acsij publication - Advances in Computer Science : an International
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acsij publication - Advances in Computer Science : an International
Advances in Computer Science: an International Journal Vol. 4, Issue 4, July 2015 © ACSIJ PUBLICATION www.ACSIJ.org ISSN : 2322-5157 ACSIJ Reviewers Committee 2015 Prof. José Santos Reyes, Faculty of Computer Science, University of A Coruña, Spain Dr. Dariusz Jacek Jakóbczak, Technical University of Koszalin, Poland Dr. Artis Mednis, Cyber-Physical Systems Laboratory Institute of Electronics and Computer Science, Latvia Dr. Heinz DOBLER, University of Applied Sciences Upper Austria, Austria Dr. Ahlem Nabli, Faculty of sciences of Sfax,Tunisia Prof. Zhong Ji, School of Electronic Information Engineering, Tianjin University, Tianjin, China Prof. Noura AKNIN, Abdelmalek Essaadi University, Morocco Dr. Qiang Zhu, Geosciences Dept., Stony Brook University, United States Dr. Urmila Shrawankar, G. H. Raisoni College of Engineering, Nagpur, India Dr. Uchechukwu Awada, Network and Cloud Computing Laboratory, School of Computer Science and Technology, Dalian University of Technology, China Dr. Seyyed Hossein Erfani, Department of Computer Engineering, Islamic Azad University, Science and Research branch, Tehran, Iran Dr. Nazir Ahmad Suhail, School of Computer Science and Information Technology, Kampala University, Uganda Dr. Fateme Ghomanjani, Department of Mathematics, Ferdowsi University Of Mashhad, Iran Dr. Islam Abdul-Azeem Fouad, Biomedical Technology Department, College of applied Medical Sciences, SALMAN BIN ABDUL-AZIZ University, K.S.A Dr. Zaki Brahmi, Department of Computer Science, University of Sousse, Tunisia Dr. Mohammad Abu Omar, Information Systems, Limkokwing University of Creative Technology, Malaysia Dr. Kishori Mohan Konwar, Department of Microbiology and Immunology, University of British Columbia, Canada Dr. S.Senthilkumar, School of Computing Science and Engineering, VIT-University, INDIA Dr. Elham Andaroodi, School of Architecture, University of Tehran, Iran Dr. Shervan Fekri Ershad, Artificial intelligence, Amin University of Isfahan, Iran Dr. G.UMARANI SRIKANTH, S.A.ENGINEERING COLLEGE, ANNA UNIVERSTIY, CHENNAI, India Dr. Senlin Liang, Department of Computer Science, Stony Brook University, USA Dr. Ehsan Mohebi, Department of Science, Information Technology and Engineering, University of Ballarat, Australia Sr. Mehdi Bahrami, EECS Department, University of California, Merced, USA Dr. Sandeep Reddivari, Department of Computer Science and Engineering, Mississippi State University, USA Dr. Chaker Bechir Jebari, Computer Science and information technology, College of Science, University of Tunis, Tunisia Dr. Javed Anjum Sheikh, Assistant Professor and Associate Director, Faculty of Computing and IT, University of Gujrat, Pakistan Dr. ANANDAKUMAR.H, PSG College of Technology (Anna University of Technology), India Dr. Ajit Kumar Shrivastava, TRUBA Institute of Engg. & I.T, Bhopal, RGPV University, India ACSIJ Published Papers are Indexed By: Google Scholar EZB, Electronic Journals Library ( University Library of Regensburg, Germany) DOAJ, Directory of Open Access Journals Bielefeld University Library - BASE ( Germany ) Academia.edu ( San Francisco, CA ) Research Bible ( Tokyo, Japan ) Academic Journals Database Technical University of Applied Sciences ( TH - WILDAU Germany) AcademicKeys WorldCat (OCLC) TIB - German National Library of Science and Technology The University of Hong Kong Libraries Science Gate OAJI Open Academic Journals Index. 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Paul Leonard Library _ San Francisco State University OALib _ Open Access Library Université Joseph Fourier _ France CIVILICA ( Iran ) CiteSeerX _ Pennsylvania State University (United States) The Collection of Computer Science Bibliographies (Germany) Indiana University (Indiana, United States) Tsinghua University Library (Beijing, China) Cite Factor OAA _ Open Access Articles (Singapore) Index Copernicus International (Poland) Scribd QOAM _ Radboud University Nijmegen (Nijmegen, Netherlands) Bibliothekssystem Universität Hamburg The National Science Library, Chinese Academy of Sciences (NSLC) Universia Holding (Spania) Technical University of Denmark (Denmark) TABLE OF CONTENTS A Survey on the Privacy Preserving Algorithm and techniques of Association Rule Mining – (pg 1-6) Maryam Fouladfar, Mohammad Naderi Dehkordi « ACASYA »: a knowledge-based system for aid in the storage, classification, assessment and generation of accident scenarios. Application to the safety of rail transport systems – (pg 7-13) Dr. Habib HADJ-MABROUK, Dr. Hinda MEJRI Overview of routing algorithms in WBAN – (pg 14-20) Maryam Asgari, Mehdi Sayemir, Mohammad Shahverdy an Efficient Blind Signature Scheme based on Error Correcting Codes – (pg 21-26) Junyao Ye, Fang Ren, Dong Zheng, Kefei Chen Multi-lingual and -modal Applications in the Semantic Web: the example of Ambient Assisted Living – (pg 27-36) Dimitra Anastasiou An Empirical Method to Derive Principles, Categories, and Evaluation Criteria of Differentiated Services in an Enterprise – (pg 37-45) Vikas S Shah A comparative study and classification on web service security testing approaches – (pg 46-50) Azadeh Esfandyari Collaboration between Service and R&D Organizations – Two Cases in Automation Industry – (pg 51-59) Jukka Kääriäinen, Susanna Teppola, Antti Välimäki Load Balancing in Wireless Mesh Network: a Survey – (pg 60-64) Maryam Asgari, Mohammad Shahverdy, Mahmood Fathy, Zeinab Movahedi Mobile Banking Supervising System- Issues, Challenges & Suggestions to improve Mobile Banking Services – (pg 65-67) Dr.K.Kavitha A Survey on Security Issues in Big Data and NoSQL – (pg 68-72) Ebrahim Sahafizadeh, Mohammad Ali Nematbakhsh Classifying Protein-Protein Interaction Type based on Association Pattern with Adjusted Support – (pg 73-79) Huang-Cheng Kuo, Ming-Yi Tai Digitalization Boosting Novel Digital Services for Consumers – (pg 80-92) Kaisa Vehmas, Mari Ervasti, Maarit Tihinen, Aino Mensonen GIS-based Optimal Route Selection for Oil and Gas Pipelines in Uganda – (pg 93-104) Dan Abudu, Meredith Williams Hybrid Trust-Driven – (pg 105-112) Recommendation System for E-commerce Networks Pavan Kumar K. N, Samhita S Balekai, Sanjana P Suryavamshi, Sneha Sriram, R. Bhakthavathsalam Correlated Appraisal of Big Data, Hadoop and MapReduce – (pg 113-118) Priyaneet Bhatia, Siddarth Gupta Combination of PSO Algorithm and Naive Bayesian Classification for Parkinson Disease Diagnosis – (pg 119-125) Navid Khozein Ghanad, Saheb Ahmadi Automatic Classification for Vietnamese News – (pg 126-132) Phan Thi Ha, Nguyen Quynh Chi Practical applications of spiking neural network in information processing and learning – (pg 133-137) Fariborz Khademian, Reza Khanbabaie ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org A Survey on the Privacy Preserving Algorithm and techniques of Association Rule Mining Maryam Fouladfar1, Mohammad Naderi Dehkordi2 Faculty of Computer Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran 1 [email protected], 2 [email protected] Abstract in order to support a variety of domains marketing, weather forecasting, medical diagnosis, and national security. But it is still a challenge to mine certain kinds of data without violating the data owners ’privacy .For example, how to mine patients private data is an ongoing problem in health care applications .As data mining become more pervasive, privacy concerns are increasing. Commercial concerns are also concerned with the privacy issue. Most organizations collect information about individuals for their own specific needs. Very frequently, however, different units within an organization themselves may find it necessary to share information. In such cases, each organization or unit must be sure that the privacy of the individual is not violated or that sensitive business information is not revealed .Consider, for example, a government, or more appropriately, one of its security branches interested in developing a system for determining, from passengers whose baggage has been checked, those who must be subjected to additional security measures. The data indicating the necessity for further examination derives from a wide variety of sources such as police records; airports; banks; general government statistics; and passenger information records that generally include personal information; demographic data; flight information; and expenditure data. In most countries, this information is regarded as private and to avoid intentionally or unintentionally exposing confidential information about an individual, it is against the law to make such information freely available. While various means of preserving individual information have been developed, there are ways for circumventing these methods. In our example, in order to preserve privacy, passenger information records can be de-identified before the records are shared with anyone who is not permitted directly to access the relevant data. This can be accomplished by deleting from the dataset unique identity fields. However, even if this information is In recent years, data mining is a popular analysis tool to extract knowledge from collection of large amount of data. One of the great challenges of data mining is finding hidden patterns without revealing sensitive information. Privacy preservation data mining (PPDM) is answer to such challenges. It is a major research area for protecting sensitive data or knowledge while data mining techniques can still be applied efficiently. Association rule hiding is one of the techniques of PPDM to protect the association rules generated by association rule mining. In this paper, we provide a survey of association rule hiding methods for privacy preservation. Various algorithms have been designed for it in recent years. In this paper, we summarize them and survey current existing techniques for association rule hiding. Keywords: Association Rule Hiding, Data Mining, Privacy Preservation Data Mining. 1. Motivation computers have promised us a fountain of wisdom but delivered a deluge of information. this huge amount of data makes it crucial to develop tools to discover what is called hidden knowledge. these tools are called data mining tools. so, data mining promises to discover what is hidden, but what if that hidden knowledge is sensitive and owners would not be happy if this knowledge were exposed to the public or to adversaries? this problem motivates for write this paper. 2. Introduction The problem of privacy preserving data mining has become more important in recent years because of the increasing ability to store personal data about users and the increasing sophistication of data mining algorithm to leverage this information. A number of data mining techniques have been suggested in recent years in order to perform privacy preserving Data mining techniques have been developed successfully to extracts knowledge 1 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org deleted, there are still other kinds of information, personal or behavioral that, when linked with other available datasets, could potentially identify subjects. To avoid these types of violations, we need various data mining algorithm for privacy preserving. We review recent work on these topics. In this paper, it has been tried to focus on data -mining background in advance, while the important part of the paper has been focusing on introduction of different approaches of data-mining and algorithms of data mining privacy preserving for sanitizing sensitive knowledge in context of mining association rules or item sets with brief descriptions. It has been tried to concentrate on different classifications of data mining privacy preserving approaches. 3. discovering all itemsets and computation time. Generally, only those item sets that fulfill a certain support requirement are taken into consideration. Support and confidence are the two most important quality measures for evaluating the interestingness of a rule. The support of the rule X →Y is the percentage of transactions in T that contain X ∩Y . It determines how frequent the rule is applicable to the transaction set T . The support of a rule is represented by the formula (1): ( ) | | | | (1) where | X∩Y| is the number of transactions that contain all the items of the rule and n is the total number of transactions. The confidence of a rule describes the percentage of transactions containing X which also contain Y . It is given by (2): Privacy Preserving Data Mining Concepts Today as the usage of data mining technology has been increasing, the importance of securing information against disclosure of unauthorized access is one of the most important issues in securing of privacy of data mining [1]. The state or condition of being isolated from the view or presence of others is privacy [2] which is associated with data mining so that we are ab le to conceal sensitive information from revelation to public [1]. Therefore to protect the sensitive rule from unauthorized publishing, privacy preserving data mining (PPDM) has focused on data mining and database security field [3]. ( ) | | | | (2) Confidence is a very important measure to determine whether a rule is interesting or not. The process of mining association rules consists of twomain steps. The first step is, identifying all the itemsets contained in the data that are adequate for mining association rules. These combinations have to show at least a certain frequency and are thus called frequent itemsets. The second step generates rules out of the discovered frequent itemsets. All rules that has confidence greater than minimum confidence are regarded as interesting. 3.1 Association Rule Mining Strategy Association rules are an important class of regularities within data which have been extensively studied by the data mining community. The problem of mining association rules can be stated as follows: Given I = {i1 , i2 , ... , im } is a set of items, T = {t1, t2 , ... , tn} is a set of transactions, each of which contains items of the itemset I . Each transaction ti is a set of items such that ti ⊆I . An association rule is an implication of the form: X →Y, where X ⊂I , Y ⊂I and X ∩Y = Ø. X (or Y ) is a set of items, called itemset. In therule X→Y, X is called the antecedent, Y is the consequent. It is obvious that the value of the antecedent implies the value of the consequent. The antecedent, also called the “left handside” of a rule, can consist either of a single item or of a whole set of items. This applies for the consequent, also called the “right hand side”, as well. Often, a compromise has to be made between 3.2 Side Effects As it is presented in (Fig. 1), R is denoted as all association rules in the database D, as well as SR for the sensitive rules, the none sensitive rules ~SR, discovered rules R’ in sanitized database D’. The circles with the numbers of 1, 2, and 3 are possible problems that respectively represent the sensitive association rules that were failed to be censored, the legitimate rules accidentally missed, and the artificial association rules created by the sanitization process. 2 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org artifactual patterns created by the adopted privacy preserving technique. For example, in [4], Oliveira and Zaiane define two metrics misses cost and artifactual pattern which are corresponding to lost information and artifactual information respectively. In particular, misses cost measures the percentage of nonrestrictive patterns that are hidden after the sanitization process. This happens when some non-restrictive patterns lose support in the database due to the sanitization process. The misses cost (MC) is computed as (4): ( ) Fig. 1 Side Effects ) (4) ( ) The percentage of sensitive information that is still discovered, after the data has been sanitized, gives an estimate of the hiding failure parameter. Most of the developed privacy preserving algorithms are designed with the goal of obtaining zero hiding failure. Thus, they hide all the patterns considered sensitive. However, it is well known that the more sensitive information we hide, the more non-sensitive information we miss. Thus, some PPDM algorithms have been recently developed which allow one to choose the amount of sensitive data that should be hidden in order to find a balance between privacy and knowledge discovery. For example, in [4], Oliveira and Zaiane define the hiding failure (HF) as the percentage of restrictive patterns that are discovered from the sanitized database. It is measured as (3): ( ) ( ) ( where # ∼ RP (D) and # ∼ RP(D′) denote the number of non-restrictive patterns discovered from the original database D and the sanitized database D′ respectively. In the best case, MC should be 0%. Notice that there is a compromise between the misses cost and the hiding failure in their approach. The more restrictive patterns they hide, the more legitimate patterns they miss. The other metric, artifactual pattern (AP), is measured in terms of the percentage of the discovered patterns that are artifacts. The formula is (5): | || | | | (5) where |X | denotes the cardinality of X . According to their experiments, their approach does not have any artifactual patterns, i.e., AP is always 0. In case of association rules, the lost information can be modeled as the set of non-sensitive rules that are accidentally hidden, referred to as lost rules, by the privacy preservation technique, the artifactual information, instead, represents the set of new rules, also known as ghost rules, that can be extracted from the database after the application of a sanitization technique. (3) where #RP (D) and #RP(D′) denote the number of restrictive patterns discovered from the original data base D and the sanitized database D′ respectively. Ideally, HF should be 0. In their framework, they give a specification of a disclosure threshold φ , representing the percentage of sensitive transactions that are not sanitized, which allows one to find a balance between the hiding failure and the number of misses. Note that φ does not control the hiding failure directly, but indirectly by controlling the proportion of sensitive transactions to be sanitized for each restrictive pattern. 4. Different Approaches Sin PPDM Many approaches have been proposed in PPDM in order to censor sensitive knowledge or sensitive association rules [5,6]. Two classifications in existing sanitizing algorithm of PPDM shown in (fig. 2). When quantifying information loss in the context of the other data usages, it is useful to distinguish between: lost information representing the percentage of non-sensitive patterns (i.e., association, classification rules) which are hidden as side-effect of the hiding process; and the artifactual information representing the percentage of 3 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org M. Atallah et al [13], tried to deal with the problem of limiting disclosure of sensitive rules. They attempt to selectively hide some frequent item sets from large databases with as little as possible impact on other, nonsensitive frequent item sets. They tried to hide sensitive rules by modifying given database so that the support of a given set of sensitive rules, mined from the database, decreases below the minimum support value. Item RestrictionBased Item AdditionBased Data-Sharing Item ObfuscationBased Sanitizing Algorithm PPDM Pattern-Sharing Heuristic Based techniques Border Based techniques Sanitizing techniques Rule RestrictionBased Data distortion techniques N. Radadiya [14] proposed an algorithm called ADSRRC which tried to improve DSRRC algorithm. DSRRC could not hide association rules with multiple items in the antecedent (L.H.S) and consequent (R.H.S.), so it uses a count of items in consequence of the sensible rules and also modifies the minimum number of transactions to hide maximum sensitive rules and maintain data quality. Data blocking techniques Exact techniques Reconstruction Based techniques Cryptography Based techniques Y. Guo [15] proposed a framework with three phases: mining frequent set, performing sanitation algorithm over frequent item sets, and generate released database by using FP-tree-based inverse frequent set mining. Fig. 2 Classification of Approaches Sanitizing Alghorithm Border-based: In this approach by the concepts of borders, the algorithm tries to preprocess the sensitive rules, so the minimum number of them will be censored. Afterward, Database quality will maintain as well while side effects will be minimized [14,9]. One of the approaches used are as follows. data-sharing: In data-sharing technique, without analyzing or any statistical techniques, data will be communicated between parties. In this approach, the algorithms suppose change database by producing distorted data in the data base [6,7,8]. pattern-sharing: In pattern-sharing technique, the algorithm tries to sanitize the rules which are mined from the data set [6,8,9]. Y. Jain et al [16] proposed two algorithms called ISL (Increase Support of Left hand side) and DSR (Decrease Support of Right hand side) to hide useful association rule from transaction data. In ISL method, confidence of a rule is decreased by increasing the support value of Left Hand Side (L.H.S.) of the rule, so the items from L.H.S. of a rule are chosen for modification. In DSR method, confi dence of a rule is decreased by decreasing the support value of Right Hand Side (R.H.S.) of a rule, so items from R.H.S. of a rule are chosen for modification. Their algorithm prunes number of hidden rules with the same number of transactions scanned, less CPU time and modification. Sanitizing techniques Heuristic-Based: Heuristic-based techniques resolves how to select the appropriate data sets for data modification. Since the optimal selective data modification or sanitization is an NP-Hard problem, heuristics is used to address the complexity issues. The methods of Heuristic based modification include perturbation, which is accomplished by the alteration of an attribute value by a new value (i.e., changing a 1value to a0- value, or adding noise), and blocking, which is the replacement of an existing attribute value with a “?” [10,11,12]. Some of the approaches used are as follows. Exact: In this approach it tries to formulate the hiding problem to a constraint satisfactory problem (CSP). The solution of CSP will provide the minimum number of transactions that have to be sanitized from the original database. Then solve it by helping binary integer 4 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org supports and support counts from original database D. The second phase runs sanitization algorithm over programming (BIP), such as ILOG CPLEX, GNU GLPK or XPRESS-MP [14, 9]. Although this approach presents a better solution among other approaches, high time complexity to CSP is a major problem. Gkoulalas and Verykios proposed an approach in finding an optimal solution for rule hiding problems [17]. frequent itemset FS and get the sanitized frequent itemsets of FS’. The third phase is to generate released database D’ from FS’ by using inverse frequent set mining algorithm. But this algorithm is very complex as it involves generation of modified dataset from frequent set. Reconstruction-Based: A number of recently proposed techniques address the issue of privacy preservation by perturbing the data and reconstructing the distributions at an aggregate level in order to perform the association rules mining. That is, these algorithms are implemented by perturbing the data first and then reconstructing the distributions. According to different methods of reconstructing the distributions and data types, the corresponding algorithm is not the same. Some of the approaches used are as follows. Cryptography-Based: In many cases, multiple parties may wish to share aggregate private data, without leaking any sensitive information at their end. This requires secure and cryptographic protocols for sharing the information across the different parties[24,25,26,27]. one of the approache used are as follows. The paper proposed by Assaf Schuster et al.[28] presents a cryptographic privacy-preserving association rule mining algorithm in which all of the cryptographic primitives involve only pairs of participants. The advantage of this algorithm isits scalability and the disadvantage is that, a rule cannot be found correct before the algorithm gathers information from k resources. Thus, candidate generation occurs more slowly, and hence the delay in the convergence of the recall. The amount of manager consultation messages is also high. Agrawal et al. [18] used Bayesian algorithm for distribution reconstruction in numerical data. Then, Agrawal et al.[19] proposed a uniform randomization approach on reconstruction-based association rule to deal with categorical data. Before sending a transaction to the server, the client takes each item and with probability p replaces it by a new item not originally present in this transaction. This process is called uniform randomization. It generalizes Warner’s “randomized response” method. The authors of [20] improved the work over the Bayesian-based reconstruction procedure by using an EM algorithm for distributionreconstruction. 5. Conclusion We present a classification and an extended description and clustering of various algorithms of association rule mining. The work presents in here, which indicates the ever increasing interest of researchers in the area of securing sensitive data and knowledge from malicious users. At present, privacy preserving is at the stage of development. Many privacy preserving algorithms of association rule mining are proposed, however, privacy preserving technology needs to be further researched because of the complexity of the privacy problem. Chen et. al. [21] first proposed a Constraint-based Inverse Itemset Lattice Mining procedure (CIILM) for hiding sensitive frequent itemsets. Their data reconstruction is based on itemset lattice. Another emerging privacy preserving data sharing method related with inverse frequent itemset mining is inferring original data from the given frequent itemsets. This idea was first proposed by Mielikainen [22]. He showed finding a dataset compatible with a given collection of frequent itemsets is NPcomplete. References [1] S.R.M. Oliveira, O.R. Zaıane, Y. Saygin, “Secure association rule sharing, advances in knowledge discovery and data mining, in: Proceedings of the 8th Pacific-Asia Conference (PAKDD2004), Sydney, Australia, 2004, pp.74–85. A FP-tree based method is presented in [23] for inverse frequent set mining which is based on reconstruction technique. The whole approach is divided into three phases: The first phase uses frequent itemset mining algorithm to generate all frequent itemsets with their [2] Elena Dasseni, Vassilios S. Verykios, Ahmed K.Elmagarmid, and Elisa Bertino, “Hiding Association 5 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Rules by using Confidence and Support,” In Proceedings of the 4th Information Hiding Workshop (2001), pp.369– 383. 15th ACM Int. Conf. Inf. Knowl. Manag. ACM Press, New York, New York, USA, pp 748–757 [18] Chris Clifton, Murat Kantarcioglou, XiadongLin and Michaed Y.Zhu, “Tools for privacy preserving distributed data mining,” SIGKDD Explorations 4, no. 2, 2002. [3] Verykios, V.S., Elmagarmid, A., Bertino, E., Saygin, Y., and Dasseni, E. Association rule hiding. IEEE Transactions on Knowledge and Data Engineering, 2004, 16(4):434-447 [19] Alexandre Evfimievski, Ramakrishnan Srikant, Rakesh Agrawal, Johannes Gehrke. Privacy Preserving Mining of Association Rules. SIGKDD 2002, Edmonton, Alberta Canada. [4] Oliveira, S.R.M., Zaiane, O.R.: Privacy preserving frequent itemset mining. In: IEEE icdm Workshop on Privacy, Security and Data Mining, vol. 14, pp. 43–54 (2002). [20] D. Agrawal and C. C. Aggarwal, "On the design and quantification of privacy preserving data mining algorithms", In Proceedings of the 20th Symposium on Principles of Database Systems, Santa Barbara, California, USA, May, 2001. [5] Oliveira SRM, Zaiane OR (2006) A unified framework for protecting sensitive association rules in business collaboration. Int J Bus Intell Data Min 1:247–287. [6] HajYasien A (2007) Preserving privacy in association rule mining. Ph. D Thesis, University of Griffith. [21] Chen, X., Orlowska, M., and Li, X., "A new framework for privacy preserving data sharing.", In: Proc. of the 4th IEEE ICDM Workshop: Privacy and Security Aspects of Data Mining. IEEE Computer Society, 2004. 47-56. [7] Oliveira SRM, Za OR, Zaiane OR, Saygin Y (2004) Secure association rule sharing. Adv. Knowl. Discov. Data Min. Springer, pp 74–85. [22] Mielikainen, T. "On inverse frequent set mining". 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[11] Verykios VS, Pontikakis ED, Theodoridis Y, Chang L (2007) Efficient algorithms for distortion and blocking techniques in association rule hiding. Distrib Parallel Databases 22:85–104. doi: 10.1007/s10619-007-7013-0 [25] Ioannidis, I.; Grama, A, Atallah, M., “A secure protocol for computing dot-products in clustered and distributed environments,” Proceedings of International Conference on Parallel Processing, 18-21 Aug. 2002, pp.379–384. [12] Saygin Y, Verykios VS, Clifton C, Saygm Y (2001) Using unknowns to prevent discovery of association rules. ACM SIGMOD Rec 30:45–54. [26] A. Sanil, A. Karr, X. Lin, and J. Reiter, “Privacy preserving analysis of vertically partitioned data using secure matrix products,” Journal of Official Statistics, 2007. [13] Atallah M, Bertino E, Elmagarmid a., et al. (1999) Disclosure limitation of sensitive rules. Proc. 1999 Work. Knowl. Data Eng. Exch. (Cat. 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Proc. 6 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org « ACASYA »: a knowledge-based system for aid in the storage, classification, assessment and generation of accident scenarios. Application to the safety of rail transport systems Dr. Habib HADJ-MABROUK1, Dr. Hinda MEJRI2 1 Ability to supervise research French Institute of Science and Technology for Transport, Land and networks [email protected] 2 Assistant Professor Higher Institute of Transport and Logistics University of Sousse, Tunisia [email protected] Regulatory context of research interest appears thus by the creation of Community institutions to the image of the European railway agency (ERA), with which France will have to collaborate; but also by the installation of safety checking and evaluation tool like the statistic statement of rail transport or the safety common goals and methods. These measurements will be essential on France as it was the case for the introduction of the railway infrastructure’s manager and like the case for the national authorities of safety (NAS). Parallel to this European dash, one also notes an awakening in France since the decree 2000-286 of the 30/03/00 relative to the railway security, which replaces the decree of the 22/03/42 which constituted hitherto, the only legal reference on the matter. France also sets up new mechanisms, contained in laws and regulations in order to improve the security level. We note the introduction of organisms or independent technical services (ITS) in charge of certification, technical organization of investigation or even the decree related to the physical and professional ability conditions of staff. Concerning the aptitude of staff, it is necessary to stress that the next challenge to take up for Europe passes by the necessary harmonization of the work conditions which is at the same time a requirement for the safety and interworking. the safety railway formerly within the competence of the only Member States and occulted a long time by the European Union, gradually will become a nearly exclusive field of the Community policy, this in particular by the means of the project of interworking. The European This study thus, shows that the safety from a theoretical and legal perspective undergoes and will undergo many changes. We notice in particular the presence of a multiplicity of actors who support and share the responsibility for the railway safety in France and Europe. Abstract Various researches in artificial intelligence are conducted to understand the transfer of expertise problem. Today we perceive two major independent research activities: the acquisition of knowledge which aims to define methods inspired specially from software engineering and cognitive psychology to better understand the transfer of expertise, and the automatic learning proposing the implementation of inductive, deductive, abductive techniques or by analogy to equip the system of learning abilities. The development of a knowledge-based support system “ACASYA” for the analysis of the safety guided transport systems insisted us to use jointly and complementary both approaches. The purpose of this tool is to first, to evaluate the completeness and consistency of accidents scenarios and secondly, to contribute to the generation of new scenarios that could help experts to conclude on the safe character of a new system. “ACASYA” consists of three learning modules: CLASCA, EVALSCA and GENESCA dedicated respectively to the classification, evaluation and generation accident scenarios. Key-words: Transport system, Safety, Accident scenario, Acquisition, Assessment, Artificial intelligence, Expert system, Machine learning. 1. 7 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org intellectual tasks and has the ambition to giving computers some of the human mind functions: learning, recognition, reasoning or linguistic expression. Our research has involved three specific aspects of artificial intelligence: knowledge acquisition, machine learning and knowledge based systems (KBS). That they are public or are deprived, they have all of the obligations to respect and partly subjected to the independent organisms control. 2. Introduction As part of its missions of expertise and technical assistance, IFSTTAR evaluates the files of safety of guided transportation systems. These files include several hierarchical analysis of safety such as the preliminary analysis of risks (PAR), the functional safety analysis (FSA), the analysis of failure modes, their effects and of their criticality (AFMEC) or analysis of the impact of the software errors [2] and [3]. These analyses are carried out by the manufacturers. It is advisable to examine these analyses with the greatest care, so much the quality of those conditions, in fine, the safety of the users of the transport systems. Independently of the manufacturer, the experts of IFSTTAR carry out complementary analyses of safety. They are brought to imagine new scenarios of potential accidents to perfect the exhaustiveness of the safety studies. In this process, one of the difficulties then consists in finding the abnormal scenarios being able to lead to a particular potential accident. It is the fundamental point which justified this work. A development of the knowledge base in a KBS requires the use of techniques and methods of knowledge acquisition in order to collect structure and formalize knowledge. It has not been possible with knowledge acquisition to extract effectively some types of expert knowledge to analysis and evaluate safety. Therefore, the use of knowledge acquisition in combination with machine learning appears to be a very promising solution. The approach which was adopted in order to design and implement the tool “ACASYA” involved the following two main activities: Extracting, formalizing and storing hazardous situations to produce a library of standard cases which covers the entire problem. This is called a historical scenario knowledge base. This process entailed the use of knowledge acquisition techniques, Exploiting the stored historical knowledge in order to develop safety analysis know-how which can assist experts to judge the thoroughness of the manufacturer’s suggested safety analysis. This second activity involves the use of machine learning techniques. If cognitive psychology and software engineering generated support methods and tools for the knowledge acquisition, the exploitation of these methods remains still limited, in a complex industrial context. We estimate that, located downstream, machine learning can advantageously contribute to complete and strengthen the conventional means of knowledge acquisition. The ACASYA tool [4], which is the subject of this paper, provides assistance in particular during the phase in which the completeness of functional safety analysis (FSA) is evaluated. Generally, the aim of FSA is to ensure that all safety measures have been considered in order to cover the hazards identified in the preliminary hazard analyses and therefore, to ensure that all safety measures are taken into account to cover potential accidents. These analyses provide safety criteria for system design and implementation of hardware and software safety. They also, impose a safety criteria related to sizing, exploitation and maintenance of the system. They can bring out adverse security scenarios that require taking the specification. The application of knowledge acquisition means, described in addition in [5], led primarily on the development of a generic model of accident scenarios representation and on the establishment of a historical knowledge base of the scenarios that includes about sixty scenarios for the risk of collision. The acquisition of knowledge is however faced the difficulty to extract the expertise evoked in each step of the safety evaluation process. This difficulty emanates from the complexity of the expertise which encourages the experts naturally, to decline their know-how through significant examples or accident scenarios lived on automated transport systems already certified or approved. Consequently, the update of expertise must be done from examples. Machine learning [[6] and [7]] makes it possible to facilitate the transfer of knowledge, in particular from experimental examples. It contributes to the development 3. Approach used to develop the “ACASYA” system The modes of reasoning which are used in the context of safety analysis (inductive, deductive, analogical, etc.) and the very nature of safety knowledge (incomplete, evolving, empirical, qualitative, etc.) mean that a conventional computing solution is unsuitable and the utilization of artificial intelligence techniques would seem to be more appropriate. The aim of artificial intelligence is to study and simulate human intellectual activities. It attempts to create machines which are capable of performing 8 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org considered by the manufacturer. These situations provide a stimulus to the expert in formulating new accident scenarios. of KBS knowledge bases while reducing the intervention of the knowledge engineer. Indeed, the experts generally consider that it is simpler to describe experimental examples or cases rather than to clarify processes of decision making. The introduction of the automatic learning systems operating on examples allows generating new knowledge that can help the expert to solve a particular problem. The expertise of a field is not only held by the experts but also, implicitly, distributed and stored in a mass of historical data that the human mind finds it difficult to synthesize. To extract from this mass of information a relevant knowledge for an explanatory or decisional aim, constitutes one of the automatic learning objectives. 4.1. Functional organization of the “ACASYA” system As is shown in figure 1, this organization consists of four main modules. The first formalization module deals with the acquisition and representation of a scenario and is part of the knowledge acquisition phase. The three other modules, CLASCA, EVALSCA and GENESCA, under the previously general principle, cover the problems of classification, evaluation and generation. CLASCA Scen ario classification The learning from examples is however insufficient to acquire all the know-how of experts and requires application of the knowledge acquisition to identify the problem to solve, extract and formalize accessible knowledge by the usual means of acquisition. In this direction, each of the two approaches can fill the weaknesses of the other. To improve the transfer process expertise, it is thus interesting to reconcile these two approaches. Our approach is to exploit by learning, the base of scenarios examples, in order to produce knowledge that can help the experts in their mission of a system safety evaluation. New scenario Static descriptio n Fo rmalization Dynamic descriptio n Class Ck EVALSCA Scen ario Ev alu ation Historical scenario kn owled ge base Su mmarized failu res likely to in duce a system fault GENESCA Scen ario Generation Gen erated scenarios Validation of gen erated scenarios 4. The “ACASYA” system of aid to safety analysis Validated scenarios Fig. 1: Functional organization of the ACASYA system [1] 4.2. Functional architecture of the “CLASCA” system mock-up The ACASYA system [[1] and [4]] is based on the combined utilization of knowledge acquisition techniques and machine learning. This tool has two main characteristics. The first is the consideration of the incremental aspect which is essential to achieve a gradual improvement of knowledge learned by the system. The second characteristic is the man/machine co-operation which allows experts to correct and supplement the initial knowledge produced by the system. Unlike the majority of decision making aid systems which are intended for a nonexpert user, this tool is designed to co-operate with experts in order to assist them in their decision making. The ACASYA organization is such that it reproduces as much as possible the strategy which is adopted by experts. Summarized briefly, safety analysis involves an initial recognition phase during which the scenario in question is assimilated to a family of scenarios which is known to the expert. This phase requires a definition of scenarios classes. In a second phase, the expert evaluates the scenario in an attempt to evolve unsafe situations which have not been CLASCA [8] is a learning system which uses examples in order to find classification procedures. It is inductive, incremental and dedicated to the classification of accident scenarios. In CLASCA, the learning process is nonmonotonic, so that it is able to deal with incomplete accident scenario data, and on other hand, interactive (supervised) so that the knowledge which is produced by the system can be checked and in order to assist the expert in formulating his expertise. CLASCA incrementally develops disjunctives descriptions of historical scenarios classes with a dual purpose of characterizing a set of unsafe situations and recognizing and identifying a new scenario which is submitted to the experts for evaluation. CLASCA contains five main modules (figure 2): 1. A scenario input module ; 2. A predesign module which is used to assign values to the parameters and learning constraints which are 9 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org combination of a set of elementary failures having the same effect on the system behavior. This evaluation approach allows to attract the attention of the expert on eventual failures not taken into account during the design phase and can cause danger to the safety of the transportation system. In this sense, it can promote the generation of new accident scenarios. required by the system. These parameters mainly affect the relevance and quality of the learned knowledge and the convergence speed of the system; 3. An induction module for learning descriptions of scenario classes ; 4. A classification module, that aims to deduct the membership of a new scenario from the descriptions classes induced previously and by referring to adequacy rate; 5. A dialogue module for the reasoning of the system and the decision of experts. In justification the system keeps track from the deduction phase in order to construct its explanation. Following this rationale phase of classification decisions, the expert decides either to accept the proposed classification (in which case CLASCA will learn the scenario) or to reject this classification. In the second case it is the expert who decides what subsequent action should be taken. He may, for example, modify the learning parameters, create a new class, edit the description of the scenario or put the scenario on one side for later inspection. The second level of processing considers the class deduced by CALASCA in order to evaluate the scenario consistency. The evaluation approach is centered on the summarized failures which are involved in the new scenario to evaluate. The evaluation of this scenario type involves the two modules below [4] (figure 3): A mechanism for learning CHARADE’s rules [9] which makes it possible to deduce sf recognition functions and so to generate a basic evaluation rules ; An inference engine which exploits the above base of rules in order to deduce which sfs are to be considered in the new scenario to assess. These two steps are detailed below-after: Validation and expert decision A classification Classification (deduction) Parameters adjustment Classification parameters Baseof historical scenarios Enrichment of the base Learning parameters Predesign Learning (induction) Acceptability conditions for a scenario New scenario for classification Historical scenario Scenarios input Current knowledge learnt (descriptions of scenario classes) Accident scenario Fig. 2: Architecture of the CLASCA system mock-up Fig. 3: Architecture of the EVALSCA system mock-up [3] 4.3. Functional architecture of the “EVALSCA” system mock-up 4.3.1. Learning from recognition functions The objective of the module EVALSCA [[1] and [4]] is to confront the list of the summarized failures (sf) proposed in the scenario to evaluate with the list of archived historical summarized failures, in order to stimulate the formulation of unsafe situations not considered by the manufacturer. A sf is a generic failure, resulting from the This phase of learning attempts, using the base of examples which was formed previously, to generate a system of rules reflecting the functions of recognition summarized failures. The purpose of this stage is to generate a recognition function for each sf associated with a given class. The sf recognition function is a production failures summarized 10 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org rule which establishes a link between a set of facts (parameters which describe a scenario or descriptors) and the sf fact. There is a logic dependency relationship, which can be expressed in the following form: 4.3.2. . Deduction of the summarized failures which are to be considered in the scenario to evaluate During the previous step, the CHARADE module created a system of rules from the current basis of learning examples and which is relative to the class Ck offered by the CALASCA system. The sf deduction stage requires beforehand, a transfer phase of rules which have been generated and transferred to an expert system in order to construct a scenario evaluation knowledge base. This evaluation contains (figure3): If Principe of cantonment (PC) and Potential risks or accidents (R) and Functions related to the risk (FRR) and Geographical _ zones (GZ) and Actors involved (AI) and Incidents _ functions (IF) Then Summarized failures (SF) The base of rules, which is split into two parts: a current base of rules which contains the rules which CHARADE has generated in relation to a class which CLASCA has suggested at the instant t and a store base of rules, which composed of the list of historical bases of rules. Once a scenario has been evaluated, a current base of rules becomes a store base of rules ; The base of facts, which contains the parameters which describe the manufacturer's scenarios to evaluate and that’s enriched, over interference, from facts or deducted descriptors. A base of evaluation rules can be generated for each class of scenarios. Any generated rule must contain the PR descriptor in its conclusion. It has proved to be inevitable to use a learning method which allows production rules to be generated from a set of historical examples (or scenarios). The specification of the properties required by the learning system and analysis of the existing has led us to choose the CHARADE’s mechanism [9]. To generate automatically a system of rules, rather than isolated rules, and its ability to produce rules in order to develop sf recognition functions make an undeniable interest to CHARADE. A sample of some rules generated by CHARADE is given below. These relate to the initialization sequence class. If Actors involved = operator _ itinerant, Incident _functions = instructions Elements-involved = operator _in _cc. Then Summarized failures = SF11 (Invisible element on the zone of completely automatic driving) Actors involved = AD _ with _redundancy, Functions related to the risk =train localization, Geographical _zones = terminus If Principle of cantonment = fixed _cantonment Functions related to the risk = initialization Incident _functions = instructions Then Summarized failures = SF10 (erroneous _re-establishment of safety frequency/high voltage), Functions related to the risk = SF10 (erroneous _re-establishment of safety frequency/high voltage permission), Functions related to the risk Functions related to the risk = alarm _management, Functions related to the risk = train _localization. [0] This scenario evaluation knowledge base which has been described above (base of facts and base of rules) exploited by forward chaining by an inference engine, generates the summarized failures which must be involved in the description of the scenario to evaluate. The plausible sfs deduced by the expert system are analyzed and compared to the sfs which have actually been considered by the scenario to evaluate. This confrontation can generate one or more sfs not taken into account in the design of protective equipment and likely to affect the safety of the transport system. The above suggestion may assist in generating unsafe situations which have not been foreseen by the manufacturer during the specification and design phases of system. [0] 4.4. Functional architecture of the “GENESCA” system mock-up In complement as of two previous levels of treatment which involve the static description of the scenario (descriptive parameters), the third level [10] involves in particular the dynamic description of the scenario (the model of Petri) like to the three mechanisms of reasoning: the induction, the deduction and the abduction. The aid in the generation of a new scenario is based on the injection of a sf, declared possible by the previous level, in a particular sequencing of Petri network marking evolution. 11 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org exploitable scenarios systematically, but only the embryos of scenarios which will stimulate the imagination of the experts in the formulation of accident scenarios. Taking into account the absence of work relative to this field, originality and complexity of problem, this difficulty was predictable and solutions are under investigation. This approach of generation includes two distinct processes: the static generation and the dynamic generation (figure 4). The static approach seeks to derive new static descriptions of scenarios from evaluating a new scenario. It exploits by automatic learning the whole of the historical scenarios in order to give an opinion on the static description of a new scenario. 5. If the purpose of the static approach is to reveal static elements which describe the general context in which the new scenario proceeds, the dynamic approach is concerned to create a dynamics in this context in order to suggest sequences of events that could lead to a potential accident. The method consists initially, to characterize by learning the knowledge implied in dynamic descriptions of historical scenarios of the same class as the scenario to evaluate and to represent them by a “generic” model. The next step is to animate by simulation this generic model in order to discover eventual scenarios that could eventually lead to one or more adverse safety situations. Conclusion The ACASYA system created to assist safety analysis for automated terrestrial transit systems satisfies classification, evaluation and generation objectives of accident scenario. It demonstrates that machine learning and knowledge acquisition techniques are able to complement each other in the transfer of knowledge. Unlike diagnostic aid systems, ACASYA is presented as a tool to aid in the prevention of design defects. When designing a new system, the manufacturer undertakes to comply with the safety objectives. He must demonstrate that the system is designed so that all accidents are covered. At the opposite, the experts of certification aim to show that the system is not safe and, in this case, to identify the causes of insecurity. Built in this second approach, ACASYA is a tool that evaluates the completeness of the analysis proposed by the manufacturer. ACASYA is at the stage of a model whose first validation demonstrates the interest of the aid to safety analysis method and which requires some improvements and extensions. More precisely, the dynamic approach involves two principal phases (figure 3): A modeling phase which must make it possible to work out a generic model of a class of scenarios. The Modeling attempts to transform a set of Petri networks into rules written in logic of proposals; A simulation phase which exploits the previous model to generate possible dynamic descriptions of scenarios. References [1] Hadj-Mabrouk H. "Apport des techniques d'intelligence artificielle à l'analyse de la sécurité des systèmes de transport guidés", Revue Recherche Transports Sécurité, no 40, INRETS, France, 1993. [2] Hadj-Mabrouk H. "Méthodes et outils d’aide aux analyses de sécurité dans le domaine des transports terrestres guidés", Revue Routes et Transports, Montréal-Québec, vol. 26, no 2, pp 22-32, Été 1996. [3] Hadj-Mabrouk H. "Capitalisation et évaluation des analyses de sécurité des automatismes des systèmes de transport guidés", Revue Transport Environnement Circulation, Paris, TEC no 134, pp 22-29, Janvier-février 1996. [4] Hadj-Mabrouk H. "ACASYA: a learning system for functional safety analysis", Revue Recherche Transports Sécurité, no 10, France, Septembre 1994, p 9-21. Fig. 4: Approach help to generating embryos accident scenarios During the development of model GENESCA, we met with methodological difficulties. The produced model does not make it yet possible to generate new relevant and 12 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [5] Angele J., Sure Y. "Evaluation of ontology –based tools workshop", 13th International Conference on Knowledge Engineering and Knowledge management EKAW 2002, Siguenza (Spain), September 30th (pp: 63-73) [6] Cornuéjols A., Micelet L., Kodratoff Y. " Apprentissage artificiel: Concepts et algorithmes", Eyrolles éd, Août 2002. [7] Ganascia J.-G "L’intelligence artificielle", Cavalier Bleu Eds, Mai 2007. [8] Hadj-Mabrouk H. "CLASCA, un système d'apprentissage automatique dédié à la classification des scénarios d'accidents", 9ème colloque international de fiabilité & maintenabilité. La Baule, France, 30 Mai-3 Juin 1994, p 1183 - 1188. [9] Ganascia J.-G. "AGAPE et CHARADE : deux mécanismes d'apprentissage symbolique appliqués à la construction de bases de connaissances", Thèse d'Etat, Université Paris-sud, mai 1987. [10] Mejri L. "Une démarche basée sur l’apprentissage automatique pour l’aide à l’évaluation et à la génération de scénarios d’accidents", Application à l’analyse de sécurité des systèmes de transport automatisés. Thèse de doctorat, Université de Valenciennes, 6 décembre 1995, 210 p. 13 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Overview of routing algorithms in WBAN Maryam Asgari 1, Mehdi Sayemir 2, Mohammad Shahverdy 3 1 Computer Engineering Faculty, Islamic Azad University, Tafresh, Iran [email protected] 2 Safahan Institute Of Higher Education, Esfahan, Iran [email protected] 3 Computer Engineering Faculty, Islamic Azad University, Tafresh, Iran [email protected] increased medical costs As research on this subject shows that medical expenses in the year 2022 will specialty 20% of America's GDP in which in its own field is a major problem for the government. As another proof of this claim, we can mention the growth of medical costs in America 85/1 trillion in 1980 to $ 250 billion in 2004. This is despite the fact that 45 million people in America are without health insurance. Checking these statics only brings one thing to the researchers mind and that is the need of change in health systems so that the costs of treatment is lowered and the health care in form of Prevention is raised [2, 3, 4, 5, 6 and 7]. Abstract The development of wireless computer networks and advances in the fabrication of integrated electronic circuits is one of the key elements in making miniature sensors, Makes it possible to use the wireless sensor networks for environmental monitoring in and around the bodies of animals. This precinct of researches is called the wireless research around the body or WBAN and IEEE Institute has assigned two standards to this matter being LEEE.802.15.6 and IEEE.802.15.4. WBAN aim to facilitate, accelerate and improve the accuracy and reliability of medical care and Because of its wide range of challenges, many studies have been devoted to this precinct. according to IEEE.802.15.6 , the topology in WBAN is in star form and one step and two step communications are supported but Due to changes in body position and the different states of the human that body takes (for example walking , running , sitting and …) connecting nodes in one or two step mode via sync or PDA is not always possible . The possibility of using multi-step communication and in result the existence of multiple ways between Source and destination brings up this question that in which way and by which adjoining the transmitter sends the data to the receiver. So far, many routing algorithms have been proposed to address this question in this article we are going to evaluate them. WBAN has come to increase the speed and Accuracy of health care, provide quality for human life by providing cost savings. The sensors in WBAN networks be put inside or on the body. In both ways, nodes need to wirelessly communicate with sink and as a result making radiation that can increase the temperature of nodes and its surrounding areas in long periods and as the result be harmful for body and bring serious injuries to surrounding tissues [1]. Broadly speaking, proposing any way to reduce the amount of damage to the tissues, is based on the following two rules: Keywords: Routing Algorithms, WBAN 1. Introduction 1. Reducing the power of sent signals via the transmitter of sink According to the latest census and statistical analysis, the population of the world is increasing and on the other hand, with the development of medical technologies and social security, increased life expectancy and therefore, the aging of the population, is inevitable [1]. The aging of the population, however, causes problems such as the need for medical care for the elderly, and thus leads to 2. Using multi step communication instead of one step communication It is clear that the lower power of sent signals are , the lower area surrounding node is damaged but with lowering the power of sent signals ,communications between transmitter and sink are more likely to 14 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org disconnect and in other word , Reliability link will be reduced. have more initiative in times of crisis [2, 3]. Statistics show that more than 30% of the causes of death in developed countries is due to cardiovascular problems However, if monitoring technology is used it can greatly reduce the number. For example with using WBAN you can steadily monitor blood pressure, body temperature and heart rate of the patient, which are all vital signs. WBAN sensors can send amount of vital signals via a device connected to the internet for example cell phone after they are measured. Cell phone can send the data via phone’s internet connection to the doctor or the medical team and at the end; medical team can decide what is necessary to do. Due to need of keeping the connection active due to sensitivity of its usage being so important, the need of making guarantied links is of high priority. Providing the availability of the reliability of links is needed in high levels. All of these challenges make it Inevitable to change the one step connections to sync and multi-step connections. As mentioned on IEEE 802.15.6 standard , topologies of WBAN are in star shape motion , so that connection between nodes and sink (hub) is one or two stepped because human body experiences different motions in limited time (motions like running , walking , sitting ,sleeping , ...)there is always a chance that connection between nodes and sink to be broken and network become partition [8, 9, 10]. A solution to solve this problem is that nodes improve their signal power but as mentioned, this solution will result in nodes to have temperature rise and as the result to have tissues surrounding the nodes to injure and as the result using multi step connection is inevitable. [11, 12, 13 and 14] Ways of using WBAN in medical field is parted to three sections: 1.hideable WBANs : these clothing or in more formal way , wearable equipment , normally can be cameras , sensors for checking vital signals ,sensors for communication with a central unit and sensors for controlling the surrounding area of the person .for example for military use , with equipping soldiers with these clothes they can be tracked ,measured their activity ,tiredness or even check their vital signals and plus that if athletes use this clothes they can check their medical symptoms online and at will that will result in lowering the possibility of injuries for another example There may be cases in which a patient is allergic to substances or gases Thus, using this type of clothing, the patient may be alerted before dangerous disorders happen and will the place Thus, for any reason and in any position to look at the relationship between wireless nodes, replacing a single communication step with the sink, the tie will be a useful step. The ability of using multi step communication and as of result being multiple ways between source and destination brings up this question that in which way and with which tool the transmitter sends its data to the receiver. So far, many routing algorithms have been proposed to address this question in this article we are going to evaluate them. 2. WBANs placed inside of the body: Statistics show that in 2012, 4.6 percent of people in the world, nearly 285 million people suffer from diabetes and it is expected that in 2030 this figure will reach 438 million Research also shows that in the absence of control of the disease, many problems such as loss of vision, will threaten the patient. Using sensors and functions that are embedded in the body, such as a syringe that when it’s necessary it will insert suitable dosage of insulin to patient’s body can greatly facilitate the process of controlling diabetes. Plus, as mentioned, one of the leading causes of death worldwide is cancer and is predicted that in 2020, more than 15 million people will die from this disease. If the built-in WBAN is used, the ability to monitor the growth of cancer cells is provided thus Control tumor growth and reduce the death toll is easily accessible Other parts of this article have been sorted as follows: Second part is devoted to the usage of WBAN in medical field. Third part describes the problems in navigation of WBAN and in forth section is devoted to analyzing some well-known navigation algorithms and comparison and assessment are provided in fifth Section. The conclusion is in sixth section. 2. Usage of WBAN in medical field Due to the growth of technology, usage of medical care services will result in a Massive transformation in health field. There are expeditions that using WBAN will significantly change the systems of health care and will make doctors able to have more speed and accuracy in finding out the illnesses and to 15 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org 3.control tools and medical equipment’s in longdistance : the ability of WBAN sensors to connect to internet ,being able to have network between tools and medical equipment’s and Provides an acceptable controlling of the equipment’s from long distance that is called living with limited assist or AAL , In addition to saving time, costs are greatly reduced. power usage between different nodes and by doing this , prevent early death. 4. Increased longevity: A good routing algorithm must be able to transfer data paths selected so that the total time of network activity increases. 5. Efficient communication radius: A good routing algorithm should consider an efficient communication radius of nodes. The higher communication range of a node is the higher the energy usage will be but if communication range of a node is very low there is a chance that the mentioned node will lose communication with other nodes and network divide to several pieces. Also If the radius of communication is very low, usually a number of options for routing to the destination are reduced this results usage a same way by a node and this result in temperature rise of the neighbor node and increase of energy usage in node 3. Routing challenges in WBAN So far, numerous routing algorithms for ado networks and wireless sensor networks have been presented WBAN networks are very much maligned to MANET in the position and motion of the nodes, of course, the movement of the nodes in the WBAN are usually grouped This means that all network nodes move with keeping their position toward one another while in MANET each node moves independently from other nodes. In addition, energy consumption is more restrictions on WBAN networks because a node insertion or replacement battery in WBAN, especially when the node is placed inside the patient's body, is much harder than replacing a node in a traditional sensor networks because surgery is usually required. Hence, it is more important to have more longevity in WBAN networks also the rate of change of topology and speed in WBAN nodes is far greater than sensor networks. Based on what was said, routing protocols designed for MANET and WSN are not useable in WBAN. Challenges that are raised in the WBAN networks, are summarized below: 6. Finite number of jumps: as mentioned before, number of jumps in WBAN standard must be one to two steps. Use of higher-quality channels can increase the reliability of packets but at the same time usually the number of steps are increased, however, despite restrictions on the number of steps in the IEEE 802.15.6 standard is intended, routing algorithms usually do not pay attention to these limitations. 7. Usage in Heterogeneous Environments: WBANs usually consists of different sensors with different data transfer rates. Routing algorithms must be able to provide quality services in a variety of different applications. 1. body movements: moving of nodes because of human body position causes serious problems for providing service in WBAN Because the quality of the communication channel between nodes with each other, as a function of time and due to changes in posture of body, is not stable As a result, an appropriate routing algorithm must be able to adapt itself to a variety of changes in the network topology. 4. The routing algorithms in WBAN So far, numerous routing algorithms for a WBAN networks have been provided and each has been trying to resolve basic variety of challenges posed in the previous section. 2. The temperature and interference: The temperature of a node for computing activities or relationships with other nodes, usually increases and this increase in temperature may cause damage to the human body. A good routing algorithm must manage the data sending schedule so that a specified node is not always chosen as relay node. 4.1. OFR & DOR routing algorithms OFR routing algorithm is the same flooding algorithm used in other types of networks. As the name suggests, in this algorithm ,for sending a package between transmitter and receiver , no navigation is done but the transmitter sends the copy of the package to its neighbors .each neighbor (basically each node it network) sends the package to its neighbor after receiving it . With this method, 3. Reduce energy consumption: a good routing algorithm must be able to use intermediate nodes as the relay nodes instead of sending the data directly to a remote destination so that it prorate the overhead 16 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org multiple copies of a package arrives at the receiver. Based on this, the receiver saves the first package that has less delay and sweep away other packages. OFR method is usable in different varieties, for example, it has high reliability (because it uses all the potential of the network) and has a small delay but because of using too much resources, energy usage and temperature created in it will rise and also it has low throughput. not only consider current state of the channel but also consider the state of channel in t period of time unit before current state. Obviously, the larger the value of t is the less impact on the instantaneous channel quality will be. In other word, by determining a value of t large enough, the channel quality of real-time changes will in no way affect the amount of LLF. The quality factor of the link between node I and j at and it always has the amount time t is shown with between zero (no connection) and one (full connection) and after each time cutting , the amount will update via (1) relation : On the opposite side of OFR method is the DOR method that its function is completely opposite of OFR method. Is routing algorithm of DOR sender only sends its data to the receiver when a direct communication link is established between them and if a link is unavailable, transmitter holds its data in the buffer until it establishes the link? In other word, there is no routing in DOR. However, unlike OFR, DOR algorithm uses fewer resources, but because it does not benefit from multi step Communication, it suffers a lot of delay and sometimes it’s unacceptable, it’s because of this reason that its only usage is in networks that are sensitive to delay. Plus, by increasing the distance between transmitter and receiver, even the possibility that the sender will not be able to send data to a receiver. { ( ) (1) In each section satisfied between the link nodes I and j will increase rate of w.as mentioned , determining the amount of w will have great impacts of usage of PRPLC algorithm so that the lower the amount w is , the amount of speed of in having connection will reduce but if channel lose connection , will decrease fast.it is expected that the amount of w is in a way that for channel that have had long amount of connection will decrease slow and increase fast and vice versa , For channels that have been cut for a long time and have poor quality, and slowly increase and the decrease fast. In other word, the amount of w in each time cutting, must be updated, number 2 relation show the way of updating w: DOR and OFR algorithms are basically useless but low processing overhead and other benefits and features, are usually used to compare other algorithms. 4.2. PRPLC routing algorithm In this algorithm [15] meters known as a living link factor (LLF) is defined. Each node has a duty to calculate LLF for its link to sink and other nodes and give these information to other nodes. This factor determines how the quality of the channel between the transmitter and the other nodes is. Method of calculating LLF is that higher values for a link show that link is more likely to be in next period of time. As you know, there is always the possibility that the quality of the channel between two nodes drop due to changes in the body temporarily and after a few moments revert back to normal. For example, Assume that the communication between two nodes one on the wrist and the other one on the chest is fine in normal mode but when the person puts his hand behind his back, this channel technically will have disorder. PRPLC algorithm uses time window in calculating LLF to ignore instantaneous channel changes, in other word, while calculating LLF it will ∑ )2( In this relation is the amount of time window, also the amount of in r time cutting is 1 if the channel between I and j is connected, if not so the amount is 0. When node I wants to send data to node d and node j is in the neighborhood of node I , if node I will send its data to node j. in other word , be considering that LLF has a better position between node j and destination, node I prefers to send its data to destination via node j . 4.3. ETPA Routing algorithm In [17] an energy-aware routing algorithm that considers measured temperature and transmitting 17 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org power at the same time has been presented as ETPA. This multi-step algorithm uses a cost estimate function for choosing best neighbor. Cost of each neighbor, is a function of temperature, energy level and signal strength received from the neighbor. In this algorithm to reduce interference and eliminating the time listening to a channel, the TDMA method is used in other word , Each time frame is divided into N slots so that N is the number of network nodes and each node to send its own time slice. At the beginning of each period (includes 4 time frames), each node for example node j sends a hello message to neighbor nodes ,then each node tries to test the signal power sent from each neighbor node and record in a table. After sending hello messages, each node will be able to calculate the cost of sending via each neighbor, and then send the data is sent through the cheapest neighbor efficiency because in calculating LLD the inertia of the moving body is not important. Inertial measurement sensors can easily collect data on acceleration and direction of motion of the body. In addition, the sensors can lead to sudden changes in body movement that can detect sudden changes in the quality of the links. Algorithm BAPR [16] in summary is a routing method that combines information from the relay node selection algorithms that have emerged with inertial motion (such as ETPA & PRPLC). In this algorithm, each node has a routing table. Routing table contains of records that have 3 parts. The first part of the destination node ID, second part the ID of the relay node and the third part shows the connection fee. the meaning of connection fee is a fee of connection between transmitter node and relay node, unlike routing algorithms in MANET , routing algorithms in BARR can have several records for one destination. In BAPR relay node is chosen via communication fee in this way that nodes with highest fee are in priority for selection .the reason for this kind of choosing is that based of fee calculating method in BAPR, link with higher fee has the higher reliability and from there BPR wants to improve the chance of sending the package successfully so it chooses a relay node with higher fee. Equation (3) shows how to calculate the cost of sending from node j to node I ( ) ( ) ( ) )3( In this equation a is the non-negative factor , is the power of signal received in node I , is highest power received , is highest energy in a node (starting energy) and is highest temperature permitted in a node. Each node chooses lowest costing neighbor while sending and sends the package to that node. If a suitable neighbor is not found transmitter saves the package in its buffer and calculates the possibility of sending again in time frame. ETPA suggests that the packages for more than two time frames remain in the buffer, are discarded. The simulation results show that this algorithm has good performance In BAPR, Information relating to motor inertia and local topology is considered in calculating the cost of connection. The cost function of this algorithm collects the data of the motor inertia to cover immediate changes to network topology and network topology history to cover long-term changes in topology. That is why in BAPR when topology changes are quick, information about the movements of the body are more valuable, otherwise the history of link is more important. In this algorithm it is assumed that the momentum vector of the body ⃗⃗⃗⃗⃗⃗⃗⃗ can be measured via inertial measurement sensors 4.4. BAPR routing algorithm As we saw, PRPLC algorithm tries to minimize the effects of instantaneous channel quality vibrations in estimating function of channel quality. This way of viewing the channel, has a big problem and that is Topology changes that occur due to changes in body position, the will not affect the channel quality measurement functions in speed. In other word , although occurring things like getting blocked , does not affect the salary factor of channel in PRPLC algorithm but accruing an event for a long time will slowly effect LLF. Considering that in situations in terms of walking or running, the body is constantly changing, PRPLC algorithm will basically lose its 5. Comparison and Analysis In this part of the article we are going to review, analyze and evaluate routing algorithms described in the previous section. The most important criteria in evaluating the performance of a routing algorithm in WBAN networks are mainly longevity and energy efficiency, reliability, successful delivery rate, packet delay. Therefore we will appraisal BAPR, ETPA and PRPLC algorithms in terms of the criteria for successful and use OFR and DOR algorithms as 18 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Indicators to measure the performance of these algorithms. expected, the number of jumps in OFR routing algorithm is more than other algorithms while the DOR algorithm has a minimum number of jumps in between other algorithms (just one jump).number of jumps in BAPR algorithm is in better place than PRPLC and ETPR but there is not a high difference between BAPR and ETPA algorithms. Of course we need to mention that the number of jumps in just calculated for packages that have been delivered successfully thus eliminating packages in PRPLC and ETPA prevents the increase of steps in algorithms. 5.1. Average rate of successful delivery As figure 1 shows, fee of delivering the massage in OFR algorithm is higher than every other algorithms and BAPR algorithm is in second place with a small difference from OFR. As you see, delivery fee price in BAPR in 30 percent higher than PRPLC algorithm that is a significant improvement Fig1. The average rate of successful delivery Figure 3: Average number of jumps 5.2. Average end to end delay 5.4. Other parameters Connection in every algorithm is the same except the DOP algorithm. Since OFR algorithm uses flooding method, delay in this algorithm is a lower bound for routing algorithms. In other word, none of the routing algorithms will have less delay than OFR algorithm. Based on this, delay in all three algorithms of PRPLC, ETPA and BAPR is acceptable. A class of routing algorithms does not pay attention to temperatures generated by the nodes, which in some cases can even cause damage to body tissues of the patient. While the ETPA pays special attention to this issue, as the temperature of the relay nodes, is being placed in fee estimate function. On the other side, BAPR routing algorithm is opposite of named algorithms and need equipment such as measurement sensor and inertial measurement. Although OFR algorithm has an acceptable performance most of the times but because of using network resources to much, is never used. Plus the overhead processing in ETPA and BARP are high compared to PFR and DOR but PRPLC algorithm has a medium overhead processing compared to other algorithms. 6. Conclusions Due to the growing population and increasing life expectancy, the traditional methods of treatment, will not be efficient because it imposes heavy cost to the economy of a country. With regard that prevention and care, are one of the simplest ways to reduce deaths and medical costs, WBAN networks for monitoring patient's vital parameters and injection materials needed for patient’s body in specific times Figure 2: The average end-to-end delay 5.3. the average number of jumps The number of jumps in a message, in a sense represents the amount of usage of resources. Thus, as 19 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [8] J. Xing and Y. Zhu, “A survey on body area network,” in 5th International Conference on Wireless Communications, Networking and Mobile Computing (WiCom ’09), pp. 1 –4, Sept. 2009. [9] S. Wang and J.-T. Park, “Modeling and analysis of multi-type failures in wireless body area networks with semi-markov model,” Comm. Letters., vol. 14, pp.6–8,Jan.2010. [10] K. Y. Yazdandoost and K. Sayrafian-Pour, “Channel model for body area network (BAN),” Networks,p.91,2009. [11] M. Shahverdy, M. Behnami & M. Fathy ” A New Paradigm for Load Balancing in WMNs” International Journal of Computer Networks (IJCN), Volume(3):Issue(4):2011,239 [12] “IEEE p802.15.6/d0 draft standard for body area network,” IEEE Draft, 2010. [13] D. Lewis, “IEEE p802.15.6/d0 draft standard for body area network,” in 15-10-0245-06-0006, May.2010. [14] “IEEE p802.15-10 wireless personal area networks”July,2011. [15] M. Quwaider and S. Biswas, “Probabilistic routing in on-body sensor networks with postural disconnections,” Proceedings of the 7th ACM international symposium on Mobility management and wireless access (MobiWAC), pp. 149–158, 2009. [16] S. Yang, J. L. Lu, F. Yang, L. Kong, W. Shu, M, Y. Wu, “Behavior-Aware Probabilistic Routing For Wireless Body Area Sensor Networks,” In Proceedings of IEEE Global Communication Conference (GLOBECOM), Atlanta, Ga, pp. 4444449,Dec,2013. [17] S. Movassaghi, M. Abolhasan, and J. Lipman, “Energy efficient thermal and power aware (ETPA) routing in body area networks,” in 23rd IEEE International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC), Sept. 2012. have been released. In the standard created for WBAN that is known with the name of LEEE 802.15.6 suggests star topology and one and multistep communications for sending data from nodes to sink. However, due to the change in body position during the day, one step connection of nodes to the sink will not be continuously connected. To solve this problem, using a multi-step communication has been proposed. Using multi-step communication has always coincided with the concept of synchronization, for this reason, much research has been done on routing algorithms in WBAN. In this article, we reviewed some of the proposed routing algorithms within the WBAN, discussed the strengths and weaknesses of them and finally we compared them with each other. References [1] Milenkovic, C. Otto, and E. Jovanov, “Wireless sensor networks for personal health monitoring: Issues and an implementation,” Computer Communications (Special issue: Wireless Sensor Networks: Performance, Reliability, Security, and Beyond, vol. 29, pp. 2521–2533, 2006. [2] C. Otto, A. Milenkovic’, C. Sanders, and E. Jovanov, “System architecture of a wireless body area sensor network for ubiquitous health monitoring,” J. Mob. Multimed., vol. 1, pp. 307–326, Jan.2005. [3] S. Ullah, P. Khan, N. Ullah, S. Saleem, H. Higgins, and K. Kwak, “A review of wireless body area networks for medical applications,” arXiv preprint arXiv:1001.0831, vol. abs/1001.0831, 2010. [4] M. Chen, S. Gonzalez, A. Vasilakos, H. Cao, and V. Leung, “Body area networks: A survey,” Mobile Networks and Applications, vol. 16, pp. 171–193, 2011. [5] K. Kwak, S. Ullah, and N. Ullah, “An overview of IEEE 802.15.6 standard,” in 3rd International Symposium on Applied Sciences in Biomedical and Communication Technologies (ISABEL), pp. 1 –6, Nov.2010. [6] S. Ullah, H. Higgin, M. A. Siddiqui, and K. S. Kwak, “A study of implanted and wearable body sensor networks,” in Proceedings of the 2nd KES International conference on Agent and multi-agent systems: technologies and applications, (Berlin, Heidelberg), pp. 464–473, Springer-Verlag, 2008. [7] E. Dishman, “Inventing wellness systems for aging in place,” Computer, vol. 37, pp. 34 – 41, May. 2004. 20 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org an Efficient Blind Signature Scheme based on Error Correcting Codes Junyao Ye1, 2, Fang Ren3 , Dong Zheng3 and Kefei Chen4 1 Department of Computer Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, China [email protected] 2 3 School of Information Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403,China [email protected] National Engineering Laboratory for Wireless Security, Xi’an University of Posts and Telecommunications Xi’an 710121, China [email protected] 4 School of Science, Hangzhou Normal University, Hangzhou 310000, China [email protected] The concept of blind signature was first proposed by Chaum et al.[2] in CRYPTO'82. In a blind signature mechanism, the user can get a valid signature without revealing the message or relevant information to the signer. What's more, the signer won't be able to connect the signature with the corresponding signature process in the future. In 1992, Okamoto proposed a blind signature scheme[3] based on schnorr signature[4]. In 2001, Chien et al.[5] proposed a partial blind signature scheme based on RSA public key cryptosystem. In 2007, Zheng Cheng et al.[6] proposed a blind signature scheme based on elliptic curve. There are a variety of mature blind signature scheme used in electronic cash scheme[7]. Hash function[8] can compress the message of arbitray length to fixed length. A secure hash function has the characteristic of onewayness and collision-resistance, which is widly used in digtal signature. There are many blind signature schemes at present, but the development of post-quantum computers has posed a huge threat to them. Code-based public key cryptography can resist the attack from post-quantum algorithm. Until now, just a literature[9] related to blind signature based on error correcting codes. In this paper[9], the authors proposed a conversion from signature schemes connected to coding theory into blind signature schemes, then give formal security reductions to combinatorial problems not connected to number theory. This is the first blind signature scheme which can not be broken by quantum computers via cryptanalyzing the underlying signature scheme employing Shor's algorithms[1]. In our paper, we propose a blind signature scheme based on Niederreiter [10] public key cryptosystem. Our scheme realizes the blindness, unforgeability, non-repudiation of the bind signature scheme, lastly we analyze the security of our scheme. Abstract Cryptography based on the theory of error correcting codes and lattices has received a wide attention in the last years. Shor’s algorithm showed that in a world where quantum computers are assumed to exist, number theoretic cryptosystems are insecure. Therefore, it is important to design suitable, provably secure post-quantum signature schemes. Code-based public key cryptography has the characteristic of resisting the attack from post-quantum computers. We propose a blind signature scheme based on Niederreiter PKC, the signature is blind to the signer. Our scheme has the same security as the Neiderreiter PKC.Through performance analysis, the blind signature scheme is correct; also it has the characteristic of blindness, unforgeability and non-repudiation. In addition, its efficiency is higher than the signature scheme based on RSA scheme. In the near future, we will focus our research on the group signature and threshold ring signature based on error correcting codes. Keywords: Code-based PKC, Blind Signature, Unforgeability, Non-repudiation, Error Correcting Codes. 1. Introduction Digital signature algorithms are among the most useful and recurring cryptographic schemes. Cryptography based on the theory of error correcting codes and lattices has received a wide attention in the last years. This is not only because of the interesting mathematical background but as well because of Shor’s algorithm[1], which showed that in a world where quantum computers are assumed to exist, number theoretic cryptosystems are insecure. Therefore, it is of utmost importance to ensure that suitable, provably secure post-quantum signature schemes are available for deployment, should quantum computers become a technological reality. 21 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org The remainder of this paper is organized as follows. Section 2 discusses theoretical preliminaries for the presentation. Section 3 describes the digital signature, blind signature and RSA blind scheme. Section 4 describes the proposed blind signature based on Niederreiter PKC. Section 5 formally analyses the proposal scheme and proves that the scheme is secure and efficient. We conclude in Section 6. the vector subspace , i.e. it holds that, +. 2.2 SDP and GDP A binary linear error-correcting code of length and dimension , denoted , - -code for short, is a linear subspace of having dimension . If its minimum distance is , it is called an , --code. An , --code is specified by either a generator matrix or by ( ) parity-check matrix as * + * | | +. The syndrome decoding problem(SDP), as well as the closely related general decoding problem(GDP), are classical in coding theory and known to be NPcomplete[11]. Definition 5(Syndrome decoding problem). Let r,n, and w be integers, and let (H,w,s) be a triple consisting of a . matrix , an integer w<n, and a vector Does there exist a vector of weight wt(e) such that ? Definition 6(General decoding problem). Let k,n, and w be integers, and let (G,w,c) be a triple consisting of a matrix , an integer , and a vector . Does there exist a vector such that ( ) ? 2. Preliminaries We now recapitulate some essential concepts from coding theory and security notions for signature schemes. 2.1 Coding Theory The idea is to add redundancy to the message in order to be able to detect and correct the errors. We use an encoding algorithm to add this redundancy and a decoding algorithm to reconstruct the initial message, as is showed in Fig1, a message of length is transformed in a message of length with . Noise e c= m r Channel * y=c+e 2.3 Niederreiter Public Key Cryptosystem Fig1. Encoding Process A dual encryption scheme is the Niederreiter[10] cryptosystem which is equivalent in terms of security to the McEliece cryptosystem[12]. The main difference between McEliece and Niederreiter cryptosystems lies in the description of the codes. The Niederreiter encryption scheme describes codes through parity-check matrices. But both schemes have to hide any structure through a scrambling transformation and a permutation transformation. The Niederreiter cryptosystem includes three algorithms. ( ) 1.Choose n, k and t according to ; 2.Randomly pick a parity-check matrix of an [n, k, 2t+1] binary Goppa code; 3.Randomly pick a permutation matrix ; 4.Randomly pick a ( ) ( ) invertible matrix ; 5.Calculate ; ( ) where 6.Output ( ), and is an efficient syndrome decoding algorithm. ( ) algorithm maps any bit strings to codewords of length n and constant weight t. 1.Calculate ; 2.Output c. ( ) Definition 1(Linear Code). An (n, k)-code over is a linear subspace of the linear space . Elements of are called words, and elements of are codewords. We call n the length, and k the dimension of . Definition 2(Hamming Distance, Weight). The Hamming distance d(x, y) between two words x, y is the number of positions in which x and y differ. That is, ( ) |* +|, where ( ) and ( ). Here, we use | | to denote the number of elements, or cardinality, of a set S. In particular, d(x, 0) is called the Hamming weight of x, where 0 is the vector containing n 0’s. The minimum distance of a linear code is the minimum Hamming distance between any two distinct codewords. Definition 3(Generator Matrix). A generator matrix of an (n, k)-linear code is a matrix G whose rows form a basis for the vector subspace . We call a code systematic if it can be characterized by a generator matrix G of the ( | form is the ( ) ) , where identity matrix and A, an ( ) matrix. Definition 4(Parity-check Matrix). A parity-check matrix of an (n, k)-linear code is an ( ) matrix H whose rows form a basis of the orthogonal complement of 22 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org When data are transmitted through the Internet, it is better that the data are protected by a cryptosystem beforehand to prevent them from tampering by an illegal third party. Basically, an encrypted document is sent, and it is impossible for an unlawful party to get the contents of the message, except he gets the sender’s private key to decrypt the message. Under a mutual protocol between the senders and receivers, each sender holds a private key to encrypt his messages to send out, and a public key used by the receiver to decrypt his sent-out messages. When the two message digests are verified to be identical, the recipient can have the true text message. Thus, the security of data transmission can be made sure. 1.Calculate ; 2.Calculate ( ); 3.Output . The security of the Niederreiter PKC and the McEliece PKC are equivalent. An attacker who can break one is able to break the other and vice versa [12]. In the following, by “Niederreiter PKC” we refer to the dual variant of the McEliece PKC and to the proposal by Niederreiter to use GRS codes by “GRS Niederreiter PKC”. The advantage of this dual variant is the smaller public key size since it is sufficient to store the redundant part of the matrix . The disadvantage is the fact, that the mapping algorithm slows down encryption and decryption. In a setting, where we want to send random strings, only, this disadvantage disappears as we can take ( ) as random string, where is a secure hash function. 3.2 Blind Signature The signer signs the requester’s message and knows nothing about it; moreover, no one knows about the correspondence of the message-signature pair except the requester. A short illustration of blind signature is described in the following. 1. Blinding Phase: A requester firstly chooses a random number called a blind factor to mess his message such that the signer will be blind to the message. 2. Signing Phase: When the signer gets the blinded message, he directly encrypts the blinded message by his private key and then sends the blinding signature back to the requester. 3. Unblinding Phase: The requester uses his blind factor to recover the signer’s digital signature from the blinding signature. 4. Signature Verification Phase: Anyone uses the signer’s public key to verify whether the signature is valid. 3. Digital Signatures and Blind Signatures 3.1 Digital Signature Under a protocol among all related parties, the digital signatures are used in private communication. All messages are capable of being encrypted and decrypted so as to ensure the integrity and non-repudiation of them. The concept of digital signatures originally comes from cryptography, and is defined to be a method that a sender’s messages are encrypted or decrypted via a hash function number in keeping the messages secured when transmitted. Especially, when a one-way hashing function is performed to a message, its related digital signature is generated called a message digest. A one-way hash function is a mathematical algorithm that makes a message of any length as input, but of a fixed length as output. Because its one-way property, it is impossible for the third party to decrypt the encrypted messages. Two phases of the digital signature process is described in the following. 1. Signing Phase: A sender firstly makes his message or data as the input of a one-way hashing function and then produces its corresponding message digest as the output. Secondly, the message digest will be encrypted by the private key of the sender. Thus, the digital signature of the message is done. Finally, the sender sends his message or data along with its related digital signature to a receiver. 2. Verification Phase: Once the receiver has the message as well as the digital signature, he repeats the same process of the sender does, letting the message as an input into the one-way hashing function to get the first message digest as output. Then he decrypts the digital signature by the sender’s public key so as to get the second message digest. Finally, verify whether these two message digests are identical or not. 3.3 RSA Blind System The first blind signature protocol proposed by Chaum is based on RSA system [2]. For each requester, he has to randomly choose a blind factor first and supplies the encrypted message to the signer, where ( ) . Note that is the product of two large secret primes and , and is the public key of the signer along with the corresponding secret key such that ( )( ) . The integer is called a blind factor because the signer will be blind to the message after the computation of ( ). While getting , the signer makes a signature on it directly, where ( ) and then returns the signed message to the requester. The requester strips the signature to yield an untraceable signature , where ( ), and announces the pair ( ) . Finally, anyone uses the signer’s public key to verify whether the signature is valid by checking the formula ( ) holds. 23 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org and anyone can verify the correctness by computing the following: 4. Proposed Blind Signature Scheme 4.1 Initialization Phase ( ) ( ) ( ( ) ) ( ) ( ) Because equation is equal to ( ) , signature of the message m. We randomly choose a t degree irreducible polynomial ( ) in the finite field ( ), and we get an irreducible Goppa code ( ). The generating matrix of the Goppa code is of order , the corresponding parity check matrix is of order ( ) . We then choose invertible matrix of order ( ) ( ) and permutation matrix of order . Let ( ) ( ) ( ) . The private key is ( ), the public key is ( ). is the valid 5.2 Security Analysis The blind signature scheme is based on Niederreiter PKC, so the security of the proposed signature scheme is up to the security of Niederreiter PKC. There have been several methods proposed for attacking McEliece’s system,[13],[14],etc. Among them, the best attack with least complexity is to repeatedly select k bits at random from the n-bit ciphertext vector c to form in hope that none of the selected k bits are in error. If there is no error is equal to m where is the in them, then matrix obtained by choosing k columns of G according to the same selection of . If anyone can decomposite public key , he will get , and , therefore the blind signature scheme is invalid. However, there are too many ways in decompositing , it’s about ( ) ∏ ( ), , numbers of , and respectively[15]. When n and t are large, it’s impossible to calculate, so the decomposition method is unfeasible. At present, the most efficient method on attacking the Niederreiter PKC is solving linear equations. Under such 4.2 Proposed Blind Signature Scheme There are two parties in the proposed blind signature scheme, the requester and the signer. The requester who wants the signature of a message, the signer who can sign the message into a signature. Before signing the message, the requester has to hash the message in order to hide the information of the message. 1. Hash Phase Assume the message m is of n dimension sequences, denoted as ( ). We can use a secure hash function, for example, MD5, to obtain message digest ( ), where is a selected secure hash function. 2. Blinding Phase The requester randomly chooses a invertible matrix as blinding factor, computes ( ) ( ). Then sends the blinding message B(m) to the signer. 3. Signing Phase After the signer has received the blinding message ( ), , then sends the signature computes ( ) to the user. 4. Unblinding Phase After the requester has received the signature , the requester uses invertible B to recover signature, computes as the following: ( ) ( ) So, is the real signature of the message digest ( ). 5. Verification Process Anyone can verify whether the signature is valid by computing , is the public key of the signer. If ( ) , then is the valid blind signature of the message m, otherwise, reject. an attack, the work factor is ( ) ( ), when , , ,the work factor of Niederreiter PKC is approximately , so we consider the Niederreiter PKC is secure enough. That is to say, the blind signature scheme is secure because the bind signature scheme is based on the Niederreiter PKC, they have the same security. 5.3 Blindness The blind factor is choosed randomly by the requester, only the requester knows , others can’t obtain from any other ways, the blinding process is computed as the following: ( ) ( ) Because of the privacy and randomness of , the blinding message ( ) is unknown to the signer. 5. Performance Analysis 5.4 Unforgeability 5.1 Correctness From the signature process, we can see that anyone else can’t forge the signer’s signature. If someone wants to forge the signer’s signature, firstly, he must get the blinding message ( ) from the requester, then forges a If the requester and the signer execute the process according to the above protocol, then the signature is the exact correct signature of message m signed by the signer, 24 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Niederreiter PKC. Firstly, we use hash function to hash the message to get the message digest ( ), then select randomly an invertible matrix B as blind factor to blind ( ) and get blinding message ( ). After the signer has received ( ), he will sign the ( ) by his private key. The user then unblinds what he receives, he will get the signature. By constructing the invertible matrix cleverly, we can assure the signature is correct and is verifiable. Through performance analysis, the blind signature scheme is correct, also it has the characteristic of blindness, unforgeability and non-repudiation. The security of our scheme is the same as the security of Niederreiter PKC scheme, in addition, it’s efficiency is higher than the signature scheme based on RSA scheme. The code-based cryptography can resist the attack of post-quantum computers, so the scheme is very applicable and considerable. In the near future, we will focus our research on the group signature and threshold ring signature based on the error-correcting code. signature. In order to forge a signature, the adversary will encounter two handicap, one is the blind factor which is random and secret, only the requester knows . The other problem is that even the adversary obtains the blinding message ( ), because he doesn’t know the private key , and of the signer, it’s impossible to forge a ( ). The requester message to satisfy the equation himself can’t forge the signer’s signature, in the first step, we use the hash function to hash the message and get ( ), the process of the hash function is invertible. 5.5 Non-repudiation The signature of the signer is signed by his private key , and , no others can obtain his private key, so, at any time, the signer can’t deny his signature. 5.6 Untraceability After the signature message pair ( ) is published, even the signer has the signature information, he can't connect the blinding signature with the blinding message ( ), that is to say, he can't trace the original message . Acknowledgments We are grateful to the anonymous referees for their invaluable suggestions. This work is supported by the National Natural Science Foundation of China (Nos. 61472472). This work is also supported by JiangXi Education Department (Nos. GJJ14650 and GJJ14642). 5.7 Compared with RSA References [1] P. W. Shor. Polynomial-Time Algorithms for Prime Factorization and Discrete Logarithms on a Quantum Computer. SIAM J.SCI.STATIST.COMPUT., 26:1484, 1997. [2] Chaum D. Blind Signatures system. Advances in cryptology:proceedings of Crypto 1982, Heidelberg: Springer-Verlag, 1982:199-203. [3] Okamoto T. Provable secure and practical identification schemes and corresponding digital signature schemes. CRYPTO'92. 1992: 31-52. [4] C. P. Schnorr. Efficient Identification and Signatures for Smart Cards. In Advances in Cryptology – CRYPTO ’89, LNCS, pages 239–252. Springer, 1989. [5] Chien H Y , Jan J K , and Tseng Y M . RSA-Based partially blind signature with low computation. IEEE 8sth International Conference on Parallel and Distributed Systems. Kyongju : Institute of Electrical and Electronics Engineers Computer Soeiety, 2001: 385-389. [6] Zheng Cheng, Guiming Wei, Haiyan Sun. Design on blind signature based on elliptic curve. Chongqing University of Posts and Telecommunications, 2007, (1):234-239. [7] T.Okamoto. An efficient divisible electronic cash scheme. In CRYPTO, pages 438-451, 1995. [8] I.Damgard. A design principle for hash functions. Crypto 89, LNCS 435, 416–427. [9] Overbeck, R.: A Step Towards QC Blind Signatures. IACR Cryptology ePrint Archive 2009: 102 (2009). Fig2 Signature Time We compare the blind signature time between RSA and our scheme, as is showed in Fig2. We compare four different situations, when the length of the plaintext is 128 bits, 256 bits, 512 bits and 1024 bits. From the Fig2, we can draw the conclusion that the signature time of our scheme is smaller than the signature time of the RSA shceme. So, our blind signature scheme based on Niederreiter PKC is very efficient. 6. Conclusions We propose a blind signature scheme based on Niederreiter PKC whose security based on the security of 25 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [10]Niederreiter H. Knapsack-type cryptosystems and algebraic coding theory[J]. Problems of Control and Information Theory, 1986, 15 (2) :159-166. [11]E. Berlekamp, R. McEliece, and H. van Tilborg. On the Inherent Intractability of Certain Coding Problems. IEEE Transactions on Information Theory, IT-24(3), 1978. [12]Li, Y., Deng, R., and Wang, X. the equivalence of McEliece's and Niederreiter's public-key cryptosystems. IEEE Transactions on Information Theory, Vol.40, pp.271273(1994). [13]T.R.N. Rao and K.-H. Nam. Private-key algebraic-coded cryptosystems. Proc.Crypt0 '86, pp.35-48, Aug, 1986. [14]C. M. Adams and H. Meijer. Security-related comments regarding McEliece's public-key cryptosystem. Roc. Crypto '87, Aug,1987. [15]P. J. Lee and E. F. Brickell. An Observation on the Security of McEliece’s Public-Key Cryptosystem. j-LECT-NOTESCOMP-SCI, 330:275–280, 1988. Junyao Ye is a Ph.D. student in Department of Computer Science and Engineering, Shanghai JiaoTong University, China. His research interests include information security and code-based cryptography. Fang Ren received his M.S. degree in mathematics from Northwest University, Xi’an, China, in 2007. He received his Ph.D. degree in cryptography from Xidian University, Xi’an, China, in 2012. His research interests include Cryptography, Information Security, Space Information Networks and Internet of Things. Dong Zheng received his Ph.D. degree in 1999. From 1999 to 2012, he was a professor in Department of Computer Science and Engineering, Shanghai Jiao Tong University, China. Currently, he is a Distinguished Professor in National Engineering Laboratory for Wireless Security, Xi’an University of Posts and Telecommunications, China. His research interests include subliminal channel, LFSR, code-based systems and other new cryptographic technology. Kefei Chen received his Ph.D. degree from Justus Liebig University Giessen, Germany, in 1994. From 1996 to 2013, he was a professor in Department of Computer Science and Engineering, Shanghai Jiao Tong University, China. Currently, he is a Distinguished Professor in School of Science, Hangzhou Normal university, China. His research interests include cryptography and network security. 26 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Multi-lingual and -modal Applications in the Semantic Web: the example of Ambient Assisted Living Dimitra Anastasiou Media Informatics and Multimedia Systems, Department of Computing Science, University of Oldenburg, 26121 Oldenburg, Germany [email protected] digital libraries. The challenges of the SW at that time were the development of ontologies, formal semantics of SW languages, and trust and proof models. Zhong et al. [3] were in search of the “Wisdom Web” and Web Intelligence where “the next-generation Web will help people achieve better ways of living, working, playing, and learning.“ The challenges described in [2] have now been sufficiently addressed, whereas the vision presented in [3] has not yet gained ground. d‟ Aquin et al. [4] presented the long-term goal of developing the SW into a large-scale enabling infrastructure for both data integration and a new generation of intelligent applications with intelligent behavior. They added that some of the requirements of an application with large-scale semantics are to exploit heterogeneous knowledge sources and combine ontologies and resources. In our opinion, multimedia data belong to such heterogeneous sources. The intelligent behavior of next-generation applications can already be found in some new research fields, such as AAL and Internet of Things. Many Web applications nowadays offer user interaction in different modalities (haptics, eye gaze, hand, arm and finger gestures, body posture, voice tone); few examples are presented here. Wachs et al. [5] developed GESTIX, a hand gesture tool for browsing medical images in an operating room. As for gesture recognition, Wachs et al. [6] pointed out that no single method for automatic hand gesture recognition is suitable for every application; each algorithm depends on each user‟s cultural background, application domain, and environment. For example, an entertainment system does not need the gesturerecognition accuracy required of a surgical system. An application based on eye gaze and head pose in an elearning environment is developed by Asteriadis et al. [7]. Their system extracts the degree of interest and engagement of students reading documents on a computer screen. Asteriadis et al. [7] stated that eye gaze can also be used as an indicator of selection, e.g. of a particular exhibit in a museum, or a dress at a shop window, and may assist or replace mouse and keyboard interfaces in the presence of severe handicaps. This survey paper presents related work on multilingual and multimodal applications within the field of Semantic Abstract Applications of the Semantic Web (SW) are often related only to written text, neglecting other interaction modalities and a large portion of multimedia content that is available on the Web today. Processing and analysis of speech, hand and body gestures, gaze, and haptics have been the focus of research in human-human interactions and have started to gain ground in human-computer interaction in the last years. Web 4.0 or Intelligent Web, which follows Web 3.0, takes these modalities into account. This paper examines challenges that we currently face in developing multilingual and -modal applications and focuses on some current and future Web application domains, particularly on Ambient Assisted Living. Keywords: Ambient Assisted Living, Multimodality, Multilinguality, Ontologies, Semantic Web. 1. Introduction Ambient Assisted Living (AAL) promotes intelligent assistant systems for a better, healthier, and safer life in the preferred living environments through the use of Information and Communication Technologies (ICT). AAL systems aim to support elderly users in their everyday life using mobile, wearable, and pervasive technologies. However, a general problem of AAL is the digital divide: many senior citizens and people with physical and cognitive disabilities are not familiar with computers and accordingly the Web. In order to meet the needs of its target group, AAL systems require natural interaction through multilingual and multimodal applications. Already in 1991 Krüger [1] said that “natural interaction” means voice and gesture. Another current issue to bring AAL systems into the market is interoperability to integrate heterogeneous components from different vendors into assistance services. In this article, we will show that Semantic Web (SW) technologies can go beyond written text and can be applied to design intelligent smart devices or objects for AAL, like a TV or a wardrobe. More than 10 years ago, Lu et al. [2] provided a review about web-services, agent-based distributed computing, semantics-based web search engines, and semantics-based 27 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org devices, like PC, mobile phone, PDA. In this paper, though, by “multimodality” we refer to multimodal input/output: Web. We discuss challenges of developing such applications, such as the Web accessibility by senior people. This paper is laid out as follows: in Sect. 2 we present how the multilingual and multimodal Web of Data is envisioned. Sect. 3 presents the challenges of developing multi-lingual and -modal applications. In Sect. 4 we look at some current innovative applications, including Wearable Computing, Internet of Things, and Pervasive Computing. The domain of AAL and its connection with the SW and Web 4.0 is presented in detail along with some scenarios in Sect. 5. Finally, we summarize the paper in Sect. 6. i) Multimodal input by human users (in)to Web applications, including modalities, like speech, body gestures, touch, eye gaze, etc.; for processing purposes, this input involves recognition of these modalities; ii) Multimodal output by Web applications to human users; this involves face tracking, speech synthesis, and gesture generation. Multimodal output can be found in browser-based applications, e.g. gestures are performed by virtual animated agents, but it is even more realistic to be performed by pervasive applications, such as robots. 2. Multi-linguality and -modality in the Semantic Web 2.1 Breaking the digital divide: heterogeneous target group Most SW applications are based on ontologies; regarding the multilingual support in ontologies, W3C recommends in the OWL Web Ontology Language Use Cases and Requirements [8] that the language should support the use of multilingual character sets. The impact of the Multilingual Semantic Web (MSW) is a multilingual “data network” where users can access information regardless of the natural language they speak or the natural language the information was originally published in (Gracia et al. [9]). Gracia et al. [9] envision the multilingual Web of Data as a layer of services and resources on top of the existing Linked Data infrastructure adding multilinguality in: Apart from the so-called “computer-literate” people, there are people who do not have the skills, the abilities, or the knowledge to use computers and accordingly the Web. The term “computer literacy” came into use in the mid1970‟s and usually refers to basic keyboard skills, plus a working knowledge of how computer systems operate and of the general ways in which computers can be used [12]. The senior population was largely bypassed by the first wave of computer technology; however, they find it more and more necessary to be able to use computers (Seals et al. [13]). In addition to people with physical or cognitive disabilities, people with temporal impairments (e.g. having a broken arm) or young children often cannot use computers efficiently. All the above groups profit by the interaction with multimodal systems, where recognition of gesture, voice, eye gaze or a combination of modalities is implemented. For the “computer-literate” people, multimodality brings additional advantages, like naturalness, intuitiveness, and user-friendliness. To give some examples, senior people with Parkinson have difficulties controlling the mouse, so they prefer speech; deaf-mute people are dependent on gesture, specifically sign language. Sign language, as with any natural language, is based on a fully systematic and conventionalized language system. Moreover, the selection of the modality, e.g. speech or gesture, can also be context-dependent. In a domestic environment, when a person has a tray in their hand, (s)he might use speech to open the door. Thus, as the target group of the Web is very heterogeneous, the current and future applications should be context-sensitive, personalized, and adaptive to the target‟s skills and preferences. i) linguistic information for data and vocabularies in different languages (meaning labels in multiple languages and morphological information); ii) mappings between data with labels in different languages (semantic relationships or translation between lexical entries); iii) services to generate, localize, link, and access Linked Data in different languages. Other principles, methods, and applications towards the MSW are presented by Buitelaar and Cimiano [10]. As far as multimodality is concerned, with the development of digital photography and social networks, it has become a standard practice to create and share multimedia digital content. Lu et al. [5] stated that this trend for multimedia digital libraries requires interdisciplinary research in the areas of image processing, computer vision, information retrieval, and database management. Traditional content-based multimedia retrieval techniques often describe images/videos based on low-level features (such as color, texture, and shape), but their retrieval is not satisfactory. Here the so-called Semantic Gap becomes relevant, defined by Smeulders et al. [11] as a “lack of coincidence between the information that one can extract from the visual data and the interpretation that the same data has for a user in a given situation.” Besides, multimodality may refer to multimodal 28 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org 2.2 Multimodal applications in the Semantic Web 3. Challenges in developing multi-lingual and -modal applications Historically, the first multimodal system was the “Put that there” technique developed by Bolt [14], which allowed the user to manipulate objects through speech and manual pointing. Oviatt et al. [15] stated that real multimodal applications range from map-based and virtual reality systems for simulation and training over field medic systems for mobile use in noisy environments, through to Web-based transactions and standard text-editing applications. One type of multimodal application is the multimodal dialogue system. They are applicable both in desktop and Web applications, but also in pervasive systems, such as in the car or at home (see AAL scenarios in 5.2.2). Smartkom [16] is such a system that features speech input with prosodic analysis, gesture input via infrared camera, recognition of facial expressions and emotional states. On the output side, the system features a gesturing and speaking life-like character together with displayed generated text and multimedia graphical output. Smartkom provides full “symmetric multimodality”, defined by Wahlster [17] as the possibility that all input modes are also available for output, and vice versa. Another multimodal dialogue system is VoiceApp developed by Griol et al. [18]. All applications in this system can be accessed multimodally using traditional GUIs and/or by means of voice commands. Thus, the results are accessible to motor handicapped and visually impaired users and are easier to access by any user in small hand-held devices where GUIs are in some cases difficult to employ. He et al. [19] developed a dialogue system called Semantic Restaurant Finder that is both multimodal and semantically rich. Users can interact through speech, typing, or mouse clicking and drawing to query restaurant information. SW services are used, so that restaurant information in different city/country/language are constructed, as ontologies allow the information to be sharable. Apart from dialogue systems, many web-based systems are multimodal. In the assistive domain, a portal that offers access to products is EASTIN1 [20]. It has a multilingual (users should forward information requests, and receive results, in their native language) and multimodal (offering a speech channel) front-end for end-users. Thurmair [20] tested the usability of the portal and found that most people preferred to use free text search. In this section we discuss some challenges for multilingual and -modal applications from a development perspective. A basic challenge and requirement of the future Web is to provide Web accessibility to everybody, bearing in mind the heterogeneous target group. Web accessibility means to make the content of a website available to everyone, including the elderly and people with physical or cognitive disabilities. According to a United Nations report [21], 97% of websites fail to meet the most basic requirements for accessibility by using units of measurement (such as pixels instead of percentages), which restrict the flexibility of the page layout, the font size or both. Today worldwide 650 million people have a disability and approximately 46 million of these are located in the EU. By 2015 20% of the EU will be over 65 years of age, the number of people aged 60 or over will double in the next 30 years and the number aged 80 or over will increase by 10% by 2050. These statistics highlight the timeliness and importance of the need to make the Web accessible to more senior or impaired people. W3C has published a literature review [22] related to the use of the Web by older people to look for intersections and differences between the accessibility guidelines and recommendations for web design and development issues that will improve accessibility to older people. W3C has a Web Accessibility Initiative [23], which has released accessibility guidelines, categorized into: i) Web Content: predictable and navigable content; ii) User Agents: access to all content, user control of how content is rendered, and standard programming interfaces, to enable interaction with assistive technologies; iii) Authoring Tools: HTML/XML editors, tools that produce multimedia, and blogs. Benjamins et al. [24] stated that the major challenges of SW applications, in general, concern: (i) the availability of content, (ii) ontology availability, development and evolution, (iii) scalability, (iv) multilinguality, (v) visualization to reduce information overload, and (vi) stability of SW languages. As far as multilinguality is concerned, they state that any SW approach should provide facilities to access information in several languages, allowing the creation and access to SW content independently of the native language of content providers and users. Multilinguality plays an important role at various levels [24]: i) Ontologies: WordNet, EuroWordnet etc., might be explored to support multilinguality; 1 www.eastin.eu, 10/09/14 29 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org ii) Annotations: proper support is needed that allows providers to annotate content in their native language; iii) User interface: internationalization and localization techniques should make the Web content accessible in several languages. 4. Current domain applications In the last years the usage of the Web has shifted from desktop applications and home offices to smart devices at home, in entertainment, the car, or in the medical domain. Some of the latest computing paradigms are the following: As far as the challenges related to multimodal applications are concerned, He et al. [19] pointed out that the existing multimodal systems are highly domain-specific and do not allow information to be shared across different providers. In relation with the SW, Avrithis et al. [25] stated that there is a lot of literature on multimodality in the domains of entertainment, security, teaching or technical documentation, however the understanding of the semantics of such data sources is very limited. Regarding the combination of modalities, Potamianos & Perakakis [26], among other authors, stated that multimodal interfaces pose two fundamental challenges: the combination of multiple input modalities, known as the fusion problem and the combination of multiple presentation media, known as the fission problem. Atrey et al. [27] provided a survey about multimodal fusion for multimedia analysis. They made several classifications based on the fusion methodology and the level of fusion (feature, decision, and hybrid). One other challenge of multimodal systems is low recognition. Oviatt & Cohen [28], on comparing GUIs with multimodal systems, stated that, whereas input to GUIs is atomic and certain, machine perception of human input, such as speech and gesture, is uncertain; so any recognition-based system‟s interpretations are probabilistic. This means that events, such as object selection, which were formerly basic events in a GUI (point an object by touching it) are subject to misinterpretation in multimodal systems. They see that the challenge for system developers is to create robust new time-sensitive architectures that support human communication patterns and performance, including processing users‟ parallel input and managing the uncertainty of recognition-based technologies. Apart from the above challenges, an additional challenge is twofold: i) develop multi-lingual and -modal applications in parallel and ii) tie them with a languageenhanced SW. Today there are not many applications that combine multiple modalities as input and/or output and support many natural languages at the same time. Cross [29] states that current multimodal applications typically provide user interaction in only a single language. When a software architect desires to provide user interaction in more than one language, they often write a multimodal application for each language separately and provide a menu interface to a user that permits the user to select the language that the user prefers. The drawback is that having multiple versions of the same multimodal application in various languages increases complexity, which leads to an increased error rate and additional costs. Wearable computing is concerned with miniature electronic devices that are worn on the body or woven into clothing and access the Web, resulting in intelligent clothing. A commercial product is the MYO armband by Thalmic Labs 1 with which users can control presentations, video, content, games, browse the Web, create music, edit videos, etc. MYO detects gestures and movements in two ways: 1) muscle activity and 2) motion sensing. The most recent Apple Watch 2 is designed around simple gestures, such as zooming and panning, but also senses force (Force Touch). Moreover, a heart rate sensor in Apple Watch can help improve overall calorie tracking. The Internet of Things (IoT) refers to uniquely identifiable objects and their virtual representations in an Internet structure. Atzori et al. [30] stressed that the IoT shall be the result of the convergence of three visions: things-oriented, Internet-oriented, and Semantic-oriented visions. Smart semantic middleware, reasoning over data, and semantic execution environments belong to the semanticoriented visions. A recent survey of IoT from an industrial perspective is published by Perera et al. [31]. [31] stated that “despite the advances in HCI, most of the IoT solutions have only employed traditional computer screenbased techniques. Only a few IoT solutions really allow voice or object-based direct communications.“ They also see a trend from smart home products that it also increasingly uses touchbased interactions. Pervasive context-aware systems: Pervasive/ ubiquitous computing means that information processing is integrated into everyday objects and activities. Henricksen et al. [32] explored the characteristics of context in pervasive systems: it exhibits temporary characteristics, has many alternative representations, and is highly interrelated. Chen et al. [33] developed the Context Broker Architecture, a broker agent that maintains a shared model of context for all computing entities in the space and enforces the privacy policies defined by the users when sharing their contextual information. They believe that a requirement for realizing context-aware systems is the ability to understand their situational conditions. To achieve this, it requires contextual information to be represented in ways that are adequate for machine 1 2 https://www.thalmic.com/myo/, 08/06/15 https://www.apple.com/watch/, 08/06/15 30 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org are adaptivity, individualization, self-configuration and learning aptitude. These features have been traditionally achieved with methods developed within the field of Artificial Intelligence (AI). However, they believe that the Internet has been the driving force for the further development of those methods and mentioned the problems of Web services: i) integration and evaluation of data sources, like ambient technical devices; ii) cooperation between services of different kinds, such as device services; and iii) interoperability of the above mentioned services. These problems are very similar to the interoperability issues arising between AAL system components, hence Eichelberg & Lipprandt [38] state that the success of AAL systems is tightly coupled with the progress of Semantic Web technologies. The goal of using SW technologies in AAL is to create interoperability between heterogeneous devices (products from different vendors) and/or IT services to promote cooperation between AAL systems and the emergence of innovative business models [38]. Web 4.0, the so-called Intelligent/Symbiotic Web, follows the Web 2.0 (Social Web) and Web 3.0 (Semantic Web) and is about knowledge-based linking of services and devices. It is about intelligent objects and environments, intelligent services, and intelligent products. Thus there is tight connection between Web 4.0 and AAL, since AAL is realized in smart and intelligent environments. In such environments, intelligent things and services are available, such as sensors that monitor the well being of users and transfer the data to caregivers, robots that drive users to their preferred destination, TVs that can be controlled through gestures, etc. Aghaei et al. [39] points out that Web 4.0 will be about a linked Web that communicates with humans in a similar manner that humans communicate with each other, for example, taking the role of a personal assistant. They believe that it will be possible to build more powerful interfaces, such as mind-controlled interfaces. Murugesan [40] stated that Web 4.0 will harness the power of human and machine intelligence on a ubiquitous Web in which both people and computers not only interact but also reason and assist each other in smart ways. Moreover, Web 4.0 is characterized by the so-called ambient findability. Google allows users to search the web and users‟ desktop and also extend this concept to the physical world. Some examples are to tag physical objects with the mobile phone, such as wallet, documents, but even people or animals. Users can use Google to see what objects have been tagged and Google can also locate the objects for the user. In this concept, RFID-like technology, GPS and mobile phone tricorders are needed. Also here the connection between findability and AAL is present, as smart objects with RFID are an important component of AAL and IoT (see scenarios in 5.2.2). processing and reasoning. Chen et al. [33] believe that SW languages are well suited for this purpose for the following reasons: i) RDF and OWL have rich expressive power that are adequate for modeling various types of contextual information, ii) context ontologies have explicit representations of semantics; systems with the ability to reason about context can detect inconsistent context knowledge (result from imperfect sensing), iii) SW languages can be used as meta-languages to define other special purpose languages, such as communication languages for knowledge sharing. Location-based services and positioning systems: Positioning systems have a mechanism for determining the location of an object in space, from sub-millimeter to meter accuracy. Coronato et al. [34] developed a service to locate mobile entities (people/devices) at any time in order to provide sets of services and information with different modalities of presentation and interaction. Semantic Sensor Web: Sheth et al. [35] proposed the semantic sensor Web (SSW) where sensor data are annotated with semantic metadata that increase interoperability and provide contextual information essential for situational knowledge. The SSW is the answer to the lack of integration and communication between networks, which often isolates important data streams [35]. Ambient Assisted Living (AAL): AAL is a research domain that promotes intelligent assistant systems for a better, healthier, and safer life in the preferred living environments through the use of Information and Communication Technologies (ICT). More information on AAL is provided in the next Section. 5. Ambient Assisted Living The aging population phenomenon is the primary motivation of AAL research. From a commercial perspective, AAL is rich in terms of technology (from telehealth systems to robotics) but also in terms of stakeholders (from service providers to policy makers, including core technology or platform developers) (Jacquet et al. [36]). The program AAL JP [37] is a funding initiative that aims to create a better quality of life for older adults and to strengthen the industrial opportunities in Europe through the use of ICT. In the next sections we will discuss the connection between AAL and the SW and Web 4.0, the reason why ontologies play a role in AAL, and the way AAL is realized along with two scenarios 5.1 Ambient Assisted Living and Web 3.0 – Web 4.0 According to Eichelberg & Lipprandt [38], the typical features of AAL systems, as standard interactive systems, 31 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org CARE [44], which develops a fall detector, more than 200 end users in Austria, Finland, Germany and Hungary were questioned regarding the need for a fall detector; they answered that the current fall detectors (wearable systems) are not satisfactory and do not have high acceptance in the independent living context. Thus generally speaking, endusers are involved in current AAL related projects either through answering questionnaires or participating in user studies. Their involvement includes analysis of technical achievements/ requirements of the developed product, acceptance and usability of the prototypes, and also often ergonomic, cognition, and psychological aspects. As for adoption of AAL systems by end users, this depends on various aspects, such as an application‟s obtrusiveness and the willingness of users. In many AAL systems, bio-sensors (activity, blood pressure- and weight sensors) are employed to monitor the health conditions of the users. Sensors/cameras are placed at home, so that the seniors’ activities are monitored and shared between informal carers, families and friends. The assisted have to decide whether their well being should be monitored in order to avoid undesired situations, but also to keep the technology as unobtrusive as possible, so that they preserve dignity and maintain privacy and confidentiality. Weber [45] stated that an adequate legal framework must take the technology of the IoT into account and would be established by an international legislator, which is supplemented by the private sector according to specific needs. Sun et al. [46] referred to some other challenges of AAL systems: i) dynamic of service availability and ii) service mapping. The Service Oriented Architecture, which supports the connection of various services, tackles the dynamicity problem. For service mapping, ontology libraries are required to precisely describe the services. There should be a so-called “mutual assistance community” where a smart home is managed by a local coordinator to build up a safety environment around the assisted people and the elderly should find themselves with a more active living attitude [46]. To sum up, Web 4.0 can support AAL by linking intelligent things and services through Web technology keyed to sensors, like RFID and GPS. However, according to Eichelberg & Lipprandt [38], until the integration of AAL systems into the era of Web 4.0, there is still significant progress needed concerning the semantic technologies. For instance, development of tools for collaborative development of formal semantic knowledge representations; integration of domain experts and standardization; ontology matching, reasoning and evaluation as well as semantic sensor networks and “Semantic Enterprise” methods for the migration of ITprocesses in linked systems. Information of how ontologies are related to AAL is given in 6.2.1. An example project which combines sensor networks is SHIP (Semantic Heterogeneous Integration of Processes) [41]. It combines separate devices, components and sensors to yield one coherent, intelligent and complete system. The key concept of SHIP is a semantic model, which brings together the data of the physical environment and the separate devices to be integrated. One application domain of SHIP is the Bremen Ambient Assisted Living Lab 1 , where heterogeneous services and devices are combined in integrated assistants 5.2 Realization and evaluation of AAL AAL is primarily realized in domestic environments, i.e. the houses of senior people. Homes equipped with AAL technology are called smart homes. Moreover, AAL systems can be applied in hospitals and nursing homes. Generally speaking, the objective of AAL systems is to increase the quality of life of the elderly, maintain their well-being and independence. However, achieving these outcomes requires the involvement of third parties (e.g. caregivers, family) through remote AAL services. Nehmer et al. [42] distinguished three types of remote AAL services: emergency treatment, autonomy enhancement, and comfort services. The projects funded by the AAL JP programme cover solutions for prevention and management of chronic conditions of the elderly, advancement of social interaction, participation in the self-serve society, and advancement of mobility and (self-) management of daily life activities of the elderly at home. Thus AAL is multifaceted with specific sub-objectives depending on the kind of application to be developed. Regarding the involvement of end users in AAL, the project A2E2 [43] involves users in several phases of the project, including focus groups, pilots, and an effectiveness study. Three groups are used: eldery clients, care professionals, and care researchers. Users are interviewed to find out which requirements they have on the particular interface to be developed. In the project AAL applications are trans-disciplinary, because they mix automatic control with modeling of user behavior. Thus, the ability to reuse knowledge and integrate several knowledge domains is particularly important [36]. Furthermore, AAL is a very open and changing field, so extensibility is key. In addition, an AAL environment requires a standard way of exchanging knowledge between software and hardware devices. Therefore [36] believe that ontologies are well adapted to these needs: 1 i) are extensible to take into account new applications; ii) provide a standard infrastructure for sharing knowledge; 5.2.1 Ontologies and AAL www.baall.org, 05/09/13 32 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org networked ontologies. They developed the OASIS Common Ontological Framework, a knowledge representation paradigm that provides: (i) methodological principles for developing interoperable ontologies, (ii) a „hyper-ontology‟ that facilitates formal semantic interoperability across ontologies and (iii) an appropriate software infrastructure for supporting heterogeneous ontologies. iii) semantic relationships, such as equivalence, may be expressed between various knowledge sources, thus permitting easy integration. Jacquet et al. [36] presented a framework in which ontologies enable the expression of users‟ preferences in order to personalize the system behavior: it stores preferences and contains application-specific modules. Another ontology-centered design is used in the SOPRANO Ambient Middleware (SAM) [47]. SAM receives user commands and sensor inputs, enriches them semantically and triggers appropriate reactions via actuators in a smart home. The ontology is used as a blueprint for the internal data models of the components, for communication between components, and for communication between the technical system and the typically non-technical user. In AAL there is often a problem of disambiguation between complex situations and simple sensors events. For example, if the person does not react to a doorbell ring, it may indicate that they have a serious problem, or alternatively it may indicate that they are unavailable, e.g. taking a bath [48]. Therefore, Muñoz et al. [48] proposed an AAL system based on a multi-agent architecture responsible for analyzing the data produced by different types of sensors and inferring what contexts can be associated to the monitored person. SW ontologies are adopted to model sensor events and the person‟s context. The agents use rules defined on such ontologies to infer information about the current context. In the case that agents discover inconsistent contexts, argumentation techniques are used to disambiguate the situation by comparing the arguments that each agent creates. In their ontology, concepts represent rooms, home elements, and sensors along with relationships among them. Furthermore, Hois [49] designed different modularized spatial ontologies applied to an AAL application. This application has different types of information to define: (1) architectural building elements (walls), (2) functional information of room types (kitchen) and assistive devices (temperature sensors), (3) types of user actions (cooking), (4) types of furniture or devices inside the apartment and their conditions (whether the stove is in use), and (5) requirements and constraints of the AAL system (temperature regulations). Hois [49] designed different, but related, ontologies to manage this heterogeneous information. Their interactions determine the system‟s characteristics and the way it identifies potential abnormal situations implemented as ontological query answering in order to monitor the situation in concrete contexts. Last but not least, in the project OASIS, one of the challenges was to achieve interoperability spanning complex services in the areas of Independent Living, Autonomous Mobility and Homes and Workplaces, including AAL. Due to the diversity of types of services, Bateman et al. [50] suggested the support of cross-domain 5.2.2 AAL Scenarios Two AAL scenarios will now be presented that demonstrate how multi-lingual and -modal applications, coupled with SW and Web 4.0, can improve the quality of life of senior citizens: Scenario 1: John is 70 years old and lives alone in a smart home equipped with intelligent, height-adaptable devices. He just woke up and wants to put on his clothes. His wardrobe suggests to him to wear brown trousers and a blue pullover. Then he goes to the supermarket for his daily shopping. He comes back and puts his purchased products into the fridge. The fridge registers the products. Then he wants to take a rest and watch TV. He lies on the bed; the bed is set to his favourite position with the headrest and footrest being set slightly higher. While he was at the supermarket, his daughter called him. The TV informs him about this missed call. Then he wants to cook his favourite meal; he goes to the kitchen and the kitchen reminds him about the recipe going through all the steps. The next day, when he goes again to the supermarket, his mobile reminds him that he has to buy milk. Scenario 2: Svetlana is from Ukraine and lives together with Maria, 85 years old from England, at Maria‟s smart home. Svetlana is caring staff, i.e. she cooks, cleans, helps in shopping, etc. Svetlana does not speak English very well; thus she speaks in Ukrainian to Maria, but also to electronic devices (TV, oven, etc.) and Maria hears it back in English. Alternatively to the voice commands, they can control the devices through a GUI or through haptics on the devices that this is available. The above scenarios have a lot of hardware and software requirements, some of which are currently under development in the project SyncReal 1 at the University of Bremen; we will study these scenarios in more detail in the subsequent paragraphs. Intelligent devices: these are the wardrobe, fridge, cupboards, bed, and TV. The clothes in the wardrobe are marked with an RFID tag (IoT – Web 4.0) and the wardrobe can suggest to the user what to wear through 1 http://www.syncreal.de, 25/06/2013 33 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org the elderly and challenged people. The AAL market is changing and is expected to boom in the next few years as a result of demographic developments and R&D investment by industries and stakeholders. Currently the ICT for AAL is very expensive; projects test AAL prototypes in living labs that can be applied in domestic environments in the future. The technology is still often obtrusive (motion sensors), although researchers are working towards a goal of invisible technology. In addition, often the data is “noisy”, as it is based on fuzzy techniques, probabilistic systems, or Markov-based models. Generally speaking, in regards to the future of intelligent ambient technologies, not only intelligent devices (Web 4.0), but also semantic interoperability between devices and IT-services (Web 3.0) are necessary. In our opinion, as emphasized by the term “semantic”, the SW should be context-sensitive, situation-adaptive, negotiating, clarifying, meaningful, and action-triggering. All these aspects are important both for SW-based dialogue systems and multimodal interfaces including various input and output modalities. We share the opinion of O Grady et al. [54], on their vision about evolutionary AAL systems, about the necessity for an adaptive (robust and adapting in real-time), open (not propriety AAL systems), scalable (integration of additional hardware sensors), and intuitive (support for many interaction modalities) software platform that incorporates autonomic and intelligent techniques. these RFIDs and motion sensors (Beins [51]). This is useful, among other benefits, for people with memory deficit or visual impairments. It can also remind people to wash clothes if there are not many clothes left in the wardrobe. Similarly, the fridge and the cupboards register all products that are placed in and taken out by storing them in a database. This information is then transferred to other devices, such as mobile phones, so that John could see the next day that there is no more milk in the fridge (Voigt [52]). The bed is set automatically to a specific height position every time that he wants to watch TV (context-sensitive). Semantic integration of ambient assistance: John could see the missed call of his daughter on the TV owing to formal semantic modeling and open standards; the semantic interoperability allows the integration of the telephone with the TV. Speech-to-speech dialogue system: the language barrier between Svetlana and Maria is not a problem due to the speech-to-speech technology that is implemented in the home system. It includes three technologies: i) speech recognition, ii) Machine Translation, iii) speech synthesis; advantages and drawbacks of all three technologies have to be balanced. The dialogue system is also multimodal giving the possibility to interact with either through GUI, voice commands or haptics. It can be applied not only in electronic appliances, but also in robots. Information about speech-to-speech translation in AAL can be found in Anastasiou [53]. References [1] Krueger, M.W., Artificial Reality, Second Ed. Addison, Wesley, Redwood City CA, 1991. [2] Lu, S., Dong, M., Fotouhi, F., “The Semantic Web: opportunities and challenges for next-generation Web applications”, Information Research, 2002, 7 (4). [3] Zhong, N., Liu, J., Yao, Y., In search of the wisdom web. Computer, 2002, 37 (11), pp. 27-31. [4] D‟Aquin, M.D., Motta, E., Sabou, M., Angeletou, S., Gridinoc, L., Lopez, V., Guidi, D., “Toward a New Generation of Semantic Web Applications”, IEEE Intelligent Systems, 2008, pp. 20-28. [5] Wachs, J., Stern, H., Edan, Y., Gillam, M., Feied, C., Smith, M., and Handler, J., “A hand-gesture sterile tool for browsing MRI images in the OR”, Journal of the American Medical Informatics Association, 2008, 15, pp. 3321-3323. [6] Wachs, J.P., Kölsch, M., Stern, H., Edan, Y., “Vision-based hand-gesture applications”, Communications of the ACM, 2011, 54 (2), pp. 60-71. [7] Asteriadis, S., Tzouveli, P., Karpouzis, K. Kollias, S., “Estimation of behavioral user state based on eye gaze and head pose-application in an e-learning environment.”, Multimed Tools Appl, 2009, 41, pp. 469-493. [8] OWL Web Ontology Language Use Cases and Requirements: http://www.w3.org/TR/webont-req/, June 2015 [9] Gracia, E. M. Ponsoda, P. Cimiano et al. “Challenges for the multilingual Web of Data”, Journal of Web Semantics, 11: 2012, 63-71. 6. Summary and Conclusion In this paper we focused on multimodal applications of the SW and presented some challenges involved in the development of multi-lingual and -modal applications. We provided some examples of current and future application domains, focusing on AAL. As there are large individual differences in people‟s abilities and preferences to use different interaction modes, multi-lingual and -modal interfaces will increase the accessibility of information through ICT technology for users of different ages, skill levels, cognitive styles, sensory and motor impairments, or native languages. ICT and SW applications gain ground rapidly today in everyday life and are available to a broader range of everyday users and usage contexts. Thus the needs and preferences of many users should be taken into account in the development of future applications. High customization and personalization of applications is needed, both because the limitations of challenged people can vary significantly and change constantly and in order to minimize the learning effort and cognitive load. AAL can efficiently combine multimodality and SW applications in the future to increase the quality of life of 34 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [26] Potamianos, A., Perakakis, “Human-computer interfaces to multimedia content: a review”, in Maragos, P., Potamianos, A. Gros, P. (Eds), Multimodal Processing and Interaction: Audio, Video, Text, 2008, pp. 49-90. [27] Atrey, P.K., Hossain, M.A, El Saddik, A., Kankanhalli, M.S. “Multimodal fusion for multimedia analysis: a survey” Multimedia Systems, 2010, 16, pp. 345-379. [28] Oviatt, S., Cohen, P. “Multimodal interfaces that process what comes naturally”, Communications of the ACM, 2000, 43 (3), pp. 45-52. [29] Cross, C.W., Supporting multi-lingual user interaction with a multimodal application, Patent Application Publication, United States, Pub. No: US/2008/0235027, 2008. [30] Atzori, L., Iera, A., Morabito, G. “The Internet of Things: A survey”, in Computer Networks, 2010, 54, pp. 2787-2805. [31] Perera, C., Liu, C.H., Jayawardena, S., Chen, M., “A Survey on Internet of Things From Industrial Market Perspective”, in IEEE Access, 2015, 2, pp. 1660-1679. [32] Henricksen, K., Indulska, A., Rakotonirainy, A. “Modeling context information in pervasive computing systems”, in Proceedings of the 1st International Conference on Pervasive Computing, 2002, pp. 167-180. [33] Chen, H., Finin, T., Joshi, A. “Semantic Web in the Context Broker Architecture”, in Proceedings of the Second IEEE Annual Conference on Pervasive Computing and Communications, 2010, pp. 277-286. [34] Coronato, A., Esposito, M., De Pietro, G. “A multimodal semantic location service for intelligent environments: an application for Smart Hospitals”, in Personal and Ubiquitous Computing, 2009, 13 (7), pp. 527-538. [35] Sheth, A., Henson, C., Sahoo, S. “Semantic Sensor Web” IEEE Internet Computing, 2008, pp- 78-83. [36] Jacquet, C., Mohamed, A., Mateos, M. et al. “An Ambient Assisted Living Framework Supporting Personalization Based on Ontologies. Proceedings of the 2nd International Conference on Ambient Computing, Applications, Services and Technologies, 2012, pp. 12-18. [37] Ambient Assisted Living Joint Programme (AAL JP): http://www.aal-europe.eu/. Accessed 5 Mai 2015 [38] Eichelberg, M., Lipprandt, M. (Eds.), Leitfaden interoperable Assistenzsysteme - vom Szenario zur Anforderung. Teil 2 der Publikationsreihe “Interoperabilität von AAL-Systemkomponenten”. VDE-Verlag, 2013. [39] Aghaei, S., Nematbakhsh, M.A., Farsani, H.K. “Evolution of the World Wide Web: From Web 1.0 to Web 4.0.”, in International Journal of Web & Semantic Technology, 2010, 3 (1), pp. 1-10. [40] Murugesan, S. “Web X.0: A Road Map. Handbook of Research on Web 2.0, 3.0, and X.0: Technologies, Business, and Social Applications”, in Information Science Reference, 2010, pp. 1-11. [41] Autexier, S., Hutter, D., Stahl, C. “An Implementation, Execution and Simulation Platform for Processes in Heterogeneous Smart Environments”, in Proceedings of the 4th International Joint Conference on Ambient Intelligence, 2013. [42] Nehmer, J., Becker, M., Karshmer, A., Lamm, R. “Living assistance systems: an ambient intelligence approach”, in Proceedings of the 28th International Conference on Software Engineering, ACM, New York, NY, USA, 2006, pp. 43-50. [10] Buitelaar, P., Cimiano, P. (Eds.), Towards the Multilingual Semantic Web, Principles, Methods and Applications, Springer, 2014. [11] Smeulders, A., Worring, M., Gupta, A., Jain, R., “ContentBased Image Retrieval at the End of the Early Years.”, in: Proceedings of IEEE Transactions on Pattern Analysis and Machine Intelligence, 2000, 22 (12), pp. 1349-1380. [12] Computerized Manufacturing Automation: Employment, Education, and the Workplace (Washington, D. C., U.S. Congress, Office of Technology Assessment, OTACIT235, 1984. [13] Seals, C.D., Clanton, K., Agarwal, R., Doswell, F., Thomas, C.M.: Lifelong Learning: Becoming Computer Savvy at a Later Age. Educational Gerontology, 2008, 34 (12), pp. 1055-1069. [14] Bolt, R.A.: Put-that-there: Voice and gesture at the graphics interface. ACM Computer Graphics, 1980, 14 (3), pp. 262270. [15] Oviatt, S.L., Cohen, P.R., Wu, L. et al. “Designing the user interface for multimodal speech and gesture applications: State-of-the-art systems and research directions for 2000 and beyond”, in Carroll, J. (Ed.), Human-Computer Interaction in the New Millennium, 2000, 15 (4), pp. 263322. [16] Wahlster, W., Reithinger, N., Blocher, A. “SmartKom: Multimodal communication with a life-like character”, in Proceedings of the 7th European Conference on Speech Communication and Technology, 2001, pp. 1547-1550. [17] Wahlster, W. “Towards Symmetric Multimodality: Fusion and Fission of Speech, Gesture and Facial Expression”, in G nter, A., Kruse, R., Neumann, B. (Eds.): KI 2003: Advances in Artificial Intelligence. Proceedings of the 26th German Conference on Artificial Intelligence, 2003, pp. 118. [18] Griol, D., Molina, J.M., Corrales, V., “The VoiceApp System: Speech Technologies to Access the Semantic Web”, in Advances in Artificial Intelligence, 2011, pp. 393-402. [19] He, Y.; Quan, T., Hui, S.C. “A multimodal restaurant finder for semantic web”, in Proceedings of the 4th International Conference on Computing and Telecommunication Technologies, 2007. [20] Thurmair, G. Searching with ontologies – searching in ontologies: Multilingual search in the Assistive Technology domain. Towards the Multilingual Semantic Web, 2013. [21] United Nations Open Audit of Web Accessibility: http://www.un.org/esa/socdev/enable/documents/fnomensa rep.pdf [22] Web Accessibility for Older Users: A Literature Review: http://www.w3.org/TR/wai-age-literature/. Accessed 25 Aug 2013 [23] W3C Web Accessibility Initiative (WAI): http://www.w3.org/WAI/ [24] Benjamins, V.R., Contreras, J., Corcho, O., Gómez-Pérez, A. “Six Challenges for the Semantic Web”, in KR2002 Semantic Web Workshop, 2002. [25] Avrithis, Y., O‟Connor, N.E., Staab, S., Troncy, R. “Introduction to the special issue on “semantic multimedia”, in Multimedia Tools Applic, 2008, 39, pp. 143-147. 35 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org informal communication in spatially distributed groups by exploiting smart environments and ambient intelligence. In 2015 she has been awarded a Marie Curie-Individual Fellowship grant on the topic of Tangible User Interfaces. In the last years, she has supervised numerous BA, MA and PhD students. In total she has published a book (PhD version), 17 journal/magazines papers, 32 papers in conference and workshop proceedings, and she is editor of 6 workshop proceedings. In addition, she is a member of 13 programme committees for conferences and journals (such as Jounral of Information Science, Computer Standards and Interfaces journal). She has 6-year teaching experience mainly in the field of Computational Linguistics. [43] A2E2 project: http://www.a2e2.eu/. Accessed 11 June 2015 [44] CARE project: http://care-aal.eu/en. Accessed 11 June 2015 [45] Weber, R.H., “Internet of Things – New security and privacy challenges”, Computer Law & Security Review, 2010, 26 (1), pp. 23-30. [46] Sun, H., De Florio, V., Gui, N., Blondia, C. “Promises and Challenges of Ambient Assisted Living Systems”, in Proceedings of the 6th International Conference on Information Technology: New Generations, 2009, pp. 1201-1207. [47] Klein, M., Schmidt, A., Lauer, R. “Ontology-centred design of an ambient middleware for assisted living: The case of SOPRANO”, in the 30th Annual German Conference on Artificial Intelligence, 2007. [48] Muñoz, A., Augusto, J.C., Villa, A., Botia, J.A. “Design and evaluation of an ambient assisted living system based on an argumentative multi-agent system, Pers Ubiquit Comput 15: 377-387, (2011) [49] Hois, J. “Modularizing Spatial Ontologies for Assisted Living Systems”, in Proceedings of the 4th International Conference on Knowledge Science, Engineering and Management, 2010, 6291, pp. 424-435. [50] Bateman, J., Castro, A., Normann, I., Pera, O., Garcia, L., Villaveces, J.M. OASIS common hyper-ontological framework, OASIS Project, Tech. Rep., 2009. [51] Beins, S.: Konzeption der Verwaltung eines intelligenten Kleiderschranks, Bachelor Thesis, Fachbereich 3: Mathematik und Informatik, University of Bremen, 2013. [52] Voigt, M. Entwicklung einer mittels Barcode-Lesegerätes automatisierten Einkaufsliste, Bachelor Thesis, Fachbereich 3: Mathematik und Informatik, University of Bremen, 2013. [53] Anastasiou, D. “Speech-to-Speech Translation in Assisted Living. Proceedings of the 1st Workshop on Robotics in Assistive Environments”, in the 4th International Conference on Pervasive technologies for Assistive Environments, 2011. [54] O‟Grady, M.J., Muldoon, C., Dragone, M., Tynan, R., O'Hare, G.M.P. “Towards evolutionary ambient assisted living systems”, Journal of Ambient Intelligence and Humanized Computing, 2010, 1 (1), pp. 15-29. Dr. Dimitra Anastasiou finished her PhD in 2010 within five years on the topic of “Machine Translation“ at Saarland University, Germany. Then she worked for two years as a postdoc in the project “Centre for Next Generation Localisation” at the University of Limerick, Ireland. There she designed guidelines for localisation and internationalisation as well as file formats for metadata, leaded the CNGL-metadata group, and was a member of the XML Interchange File Format (XLIFF) Technical Committee. In the next two years she continued with the project “SFB/TR8 Spatial Cognition” at the University of Bremen, Germany. Her research focused on multimodal and multilingual assistive environments and improvement of dialogue systems with relation to assisted living environments. She run user studies in the “Bremen Ambient Assisted Living Lab (BAALL)” with participants interacting with intelligent devices and a wheelchair/robot and did a comparative analysis of crosslingual spatial spoken and gesture commands. Currently she is working at the University of Oldenburg, Germany in the DFG project SOCIAL, which aims at facilitating spontaneous and 36 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org An Empirical Method to Derive Principles, Categories, and Evaluation Criteria of Differentiated Services in an Enterprise Vikas S Shah1 1 Wipro Technologies, Connected Enterprise Services East Brunswick, NJ 08816, USA [email protected] BPs’ associations to their activities and reorganize based on either changes to the or new BP requirements [5] and [19]. It allows accommodating the desire level of alterations and respective association in the BPs across enterprise by means of combining capabilities of more granular services or nested operations. Abstract Enterprises are leveraging the flexibilities as well as consistencies offered by the traditional service oriented architecture (SOA). The primarily reason to imply SOA is its ability to standardize way for formulating separation of concerns and combining them to meet the requirements of business processes (BPs). Many accredited research efforts have proven the advantages to separate the concerns in the aspects of one or more functional architectures such as application, data, platform, and infrastructure. However, there is not much attention to streamline the approach when differentiating composite services derived utilizing granular services identified for functional architectures. The purpose of this effort is to provide an empirical method to rationalize differentiated services (DSs) in an enterprise. The preliminary contribution is to provide abstract principles and categories of DS compositions. Furthermore, the paper represents an approach to evaluate velocity of an enterprise and corresponding index formulation to continuously monitor the maintainability of DSs. Keywords: Business Process (BP) Activities, Differentiated Services (DSs), Enterprise Entities, Maintainability, Requirements, and Velocity of an Enterprise. DSs deliver the framework to place and update BPs as well as other important capabilities of monitoring and managing an enterprise. It enterprises accelerated time-to-market, increased productivity and quality, reduced risk and project costs, and improved visibility. Enterprises often underestimate the amount of change required to adapt the concept of DSs. [15], [16], and [17] indicates that DSs are usually architected, updated, and built based on ongoing changes into the enterprise. For example, newly introduced product of digital electric meter will be added to the product database and the service to “capture the meter data remotely” gets updated explicitly and in composition with data service to formalize the capabilities of the new product. The primary concerns such as update to the data service and the behavior of digital electric meter during the outage are not being addressed or realized during later stages when the specific event occurs pertaining to the specific BP. 1. Introduction Traditionally, services of SOA are composited to associate enterprise entities and corresponding operations to business process (BP) activities. The concept of DSs is fairly novel that introduces level of variations necessary to accommodate all the potential scenarios that are required to be included within the diversified business processes [4] and [7]. DSs are the services with similar functional characteristics, but with additional capabilities, different service quality, different interaction paths, or with different outcomes [5]. DSs provide the ability to capture precise interconnectivity and subsequently the integration between BPs and the operations of enterprise entities [12]. Consequently, the entire purpose of DSs and their association with the enterprise entities are misled. It indicates that through feasibility analysis and navigation of complex cross functional changes of BPs associated with the enterprise entities are essential before updating DSs. The analysis presented in this paper identifies core characteristics of DSs and their association to the modeled BPs of an enterprise. The paper presents an approach to rationalize the relationship between the DSs and the desired variability in BP activities. The goal is to streamline and evaluate association between the BP requirements and baseline criteria to incorporate them into DSs. It sets the principles, categories, and evaluation criteria for DSs to retain the contexts and characteristics of DSs in an enterprise during various levels of updates. Typically, BP association with enterprise entities begins with assessments of the goals and objectives of the events required to accomplish the BP requirements. After modeling, BPs are implemented and consequently deployed to the platform of choice in an enterprise. The DSs have the built-in ability to considerably amend the 37 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org the decisions are based on some or other way related to the following criteria. In section 2, the primary concerns of the DSs and corresponding review of the past research efforts are presented. Section 3 provides methodology to institute DSs in an enterprise and derives preliminary principles. Identified meta-level categories of DSs are enumerated in Section 4. The classification of DSs is based on characteristics as well as anticipated behavior of the DSs. Section 5 represents the evaluation method for velocity of change in an enterprise considering 7 different BPs. Section 6 proposes and derives practical criteria to indicate maintainability of DSs depending on their classification. Section 7 presents conclusion and future work. Existing product or service offerings and their enhancements, support, and maintenance. For example, DSs associated with the online payment BP has to consider the product subscribed or in use by the customer. New products or services that will enhance revenue or gain new market share in the current or near term timeframe. The most prominent DS example is to replace electric meter with the smart meter for specific set of customers. Innovation related to future trends and competition. Product and service offerings that require immediate development, however, will not contribute to revenue until outlying years. DSs deployed to prospect search and survey to investigate interest in advanced smart grid products are the examples. Exit strategies for existing product or service offerings. Proactively determining end life of the products or services. In many cases, the previous products and services are either need to be discontinued or advanced significantly. The foremost example is videocassette recorder. 2. Literature Reviews and Primary Concerns of Introducing DSs BPs assist businesses to make decisions in order to manage the enterprise. Using a combination of a BP activities, associated metrics, and benchmarks, organizations can identify enterprise entities that are most in need of improvement. There has been an increasing adaptation of BPs to derive granular level principles for an enterprise in recent years [2], [18], [22] and [29]. The Open Group Architectural Framework (TOGAF) [31] reserves business architecture as one of the initial phase to define BPs. The Supply Chain Council’s Supply Chain Operations Reference-model (SCOR), the Tele-Management Forum’s Enhanced Telecom Operations Map (eTOM), and the Value Chain Group’s Value Reference Model (VRM) framework are the prominent examples of specifying BPs. The result of the decision process is a set of principles and key value propositions that provides differentiation and competitive advantages. Various attempts have been made either in specific use case [34] or in abstract standardization [32] and [25]. Rationalized principles have a much longer life span. These principles are direct or indirect reflection to attend the uncertainties of an enterprise. The principles should consider all the levels as well as categories of uncertainties identified or evaluated during the BP activities. In [14], three types of uncertainties are illustrated with examples. However, widely accepted enterprise architecture (EA) and other frameworks [27] and [2] aren’t addressing the complexities of implementing desired variability in BPs and corresponding BP activities. They are highly deficient in specifying synergies of the DSs to BPs in an enterprise. BP management suite providers are also offering either inherent SOA and EA capabilities or third-party integration adapters [8]. As specified in [3], [6], and [11], it is primarily to eliminate the friction between BPM, anticipated variations in services, and enterprise architecture modeling. The most prevalent examples are Oracle SOA suite [24], Red Hat JBOSS BPM and Fuse products, OpenText BPM suite, IBM BPM suite [21], and Tibco Software as indicated in [8]. BP management suites are still struggling to achieve their enterprise potential best practices to implement and update DSs. State uncertainty relates to the unpredictability that represents whether or when a certain change may occur. The example of state uncertainty is the initiation of outage process (by the utility corporation providing the outage to restoration services). Effect uncertainty relates to the inability to predict the nature of the impact of a change. During the outage due to unforeseen weather condition, it is absolutely unpredictable to know the locations or areas of impact. Response uncertainty is defined as a lack of knowledge of response options and/or an inability to predict the consequences of a response choice. Generally, utility provider has guideline for restoration during the outages, however, it is unpredictable during the situations that are never been faced before, such as undermined breaks in the circuits. The BP requirements are usually grouped to formulate the future state of an enterprise. These requirements drives the vision and guides the decisions to introduce DSs. Various different research efforts [20], [23], and [33] indicates that 38 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org level of updates and interdependencies with enterprise entities associated with the services (DSs or other types). DS needs to implement these uncertainties either proactively initiating a change or reactively responding to the change. The conclusion of various studies [9], [10], [18], and [22] indicates that first step to consistently implement and update DSs is to define principles. These principles govern maintaining DSs in the correlations with the enterprise entities and advancements of BP activities. Defining and Evolving Service Architecture: It is the primary step to define, update, version, and deploy DSs. The DS gets evolved and advanced accommodating the desired level of diversification identified in previous step. The responsibilities of this step also include evaluating the potential uncertainties and alternate path that needs to be derived in adherence to identified uncertainties. 3. Deriving Principles of DSs The decision whether to introduce additional DS, additional operation to existing DSs, or changes to the operations of existing DSs has to be achieved during this step. Modeling to map DSs with BP activities and streamlining their implementation are the part of this phase of DSs enabled enterprise. BP Requirements and Initiation The analysis of primary concerns and literature reviews illustrated in Section 2 justifies that the method for deriving principles of DSs should fundamentally have a focus at the BP requirements, identified and placed BP activities, and interdependencies between events of BP activities. The BP requirements have to be reviewed to certify the legitimacy and candidature for diversification to form DSs’ specification. Figure 1 presents a sequence of steps performed to identify principles of DSs in an enterprise and architect DSs in adherence to BP requirements. Discovering and Assessing Architecture Artifacts: When an enterprise receives alterations or new BP requirements, it needs to assess the impact in terms of other architectures associated with an enterprise (BP architecture, integration architecture, and system architecture). The responsibility of this step is to identify the need of introducing or updating architecture artifacts based on the process map (that is, association of services to the BPs or their activities). Primarily, it is accountable to identify whether any sublevel BPs (within existing BPs) and any additional BP activities required to be introduced. The need of introducing additional sublevel BPs or BP activities may be either due to critical to major advancements in BP requirements or changes necessary to other associated architecture artifacts (including integration and system architectures). Review and Validate Requirement Approved Analyze Business Impact, Conflict of Interest, and Notification Stage ACN NO Register(ed) BP Requirements YES Notification to Enterprise Business Process Architect Discovering and Assessing Architecture Artifacts BP Requirements and Initiation: The first step is to validate BP requirements alignment with business and goals of an enterprise. Stage 0 (initiation) is defined to reiterate and evaluate BP requirements at each phase (or step). When there is an ambiguity identified in the BP requirement at any step due to responsibilities associated with the corresponding step then Stage 0 has been initiated. Stage ACN is defined to analyze business impact, conflict of interest (if any exists), and notification across enterprise. Stage 0 Categorize Requirement & Send it for Review Stage ACN Integration Architect Approved NO YES Implication of Update to Infrastructure & Platform Resources Availability of Service for Diversification Feasibility Analysis of Process Map NO Systems Architect Approved Approved ITERATE NO YES YES ITERATE ITERATE Enterprise-level Composition of Service Specification BP and Activity Implications and Updated Specification Service Update Criteria and Dependencies Specification Resource Specification and Availability for Update Defining and Evolving Service Architecture Stage 0 DSs Design and Development Review Service Specification Categorize Update (Critical, Medium, High, & Low) Deployment Iterations DS Deployment and Versioning Contextual and Regression Testing YES NO Approved YES Stage 0 DS & BP Modeling, Design, and Updated Implementation NO Associating Service Administration Paradigms The other major responsibility of this step is to check availability of services for diversification based on BP requirements. It is also liable for specifying the desired Service Level Testing DS Configuration Available? Receive and Analyze User Tickets YES NO Failure? NO YES Support Ticketing & Notification Continuous Auditing and Monitoring of SLAs YES Stage 0 Approved Notification of Iteration NO DS Monitoring Evaluating Resources based on Scale of Update DS Description and End-point Configuration Approved Resolve? YES NO Fig. 1 Steps to identify principles of DSs and architect DSs in an enterprise. 39 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Associating Service Administration Paradigms: Specifying and resolving interdependencies of DSs with participant enterprise entities are the responsibilities of this step. It needs to ensure that DSs are in adherence to the availability of the enterprise resources and their defined Service Level Agreements (SLAs). Configuration, monitoring, and supporting DSs in association with enterprise entities (including any failure condition or resolution to uncertainties) are also the accountability of this step to derive principles of DSs in an enterprise and provide informed architecture decisions for DSs. 4. Identified Categories of DSs Due to increasing availability and development of SOA and BPs [26] and [28] platforms, services are being characterized in numerous different aspects. The foremost utilized classification methodology is functional architecture types such as platform services, data services, application services, and infrastructure services. Another approach is to classify industry segment specific services such as healthcare services, utility services, and payment services. Certain enterprises are also inclined to introduce custom classification of the services due to unavailability of the standards as well as rationalization. Following are the principles derived to identify, specify, develop, and deploy DSs in an enterprise based on the steps necessary to achieve BP requirements. Each step identified in Figure 2 reveals and constitutes the foundation for deriving the principles of DSs in relationship with BP requirements. Identified principles of DSs indicate that DSs are required reacting to the set of events associated with BP activities. DSs are independently built or composited utilizing one or more types of services placed in an enterprise. DSs need to be categorized such that each type can be streamlined based on their characteristic and governed based on the type of SLAs associated with them. Following is the list of identified categories of DSs based on their characteristics. Specification of DS’s operation into information that can be utilized in BPs in the context of concrete activities. The most prominent example is BP activity “generate invoice” needs DS that retrieves and combines the information of purchased products and their current pricing. Deterministic specification of relationship between BP activities and enterprise entities in DS. In the example of BP activities generate invoice, if any discount has to be implied then it needs to be in correlations with the pricing of the product. Precisely define BP activity’s events that can be emulated, monitored, and optimized through DS. The BP activity “generate invoice” request requires to be validated before retrieving the other related information. Impact of people, processes, and product (or service) offerings as metadata associated with the DS. The BP activity “generate invoice” can only be initiated by specific role associated with the employee (example: manager) or triggered by another activity such as “completed order”. Specify and govern SLAs of DS in the context of associated BP activity. The invoice should be generated within 3 seconds of completing order is an example of SLA. Regularly place and evaluate governance paradigms for DS in association with BP activity to address uncertainties. The BP activity “cancel order” or “returning an item (or product)” can occur after invoice has been generated. If those activities are not defined and updating, canceling or revising invoicing capabilities are not defined then it needs to be introduced. Competency Services: DSs that participates to satisfy one or more competencies of the core business offerings are categorized as competency services. Certain features between different versions of the same product-line are generic and essential, however, some features need to be distinguished in the DS. Relationship Services: DSs presenting external and internal relationships of the enterprise entities with the role associated with the entities such as customer, partner, and supplier. The example of such DS is the relationship of order with customer differs from the vendor and corresponding action needs to differ in the operations of DS. Collaboration Services: Any DS offering collaboration among varied enterprise entities and BP activities are considered the participant of collaborative service category. Calendar request to schedule the product review meeting is the type of collaborative service where participants can be either reviewer, moderator, or optional. Common Services: When an enterprise gain maturity, it needs to have standardized audit, log, and monitor capabilities. These standardized DSs falls in the category of common services. They are built to utilize consistently across multiple sets of BP activities with specific objective to monitor. Generating invoice and amount paid for an order are different BP activities, however, the number of item purchased are same and they are required to be monitored as well as verified between BP activities. 40 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Instance identification of the DS. Category of the DS. BP name and activity utilizing the DS. Registered consumer group and associated role using the DS. Service’s probability of failure (recursively identified from the audit logs). Framework Services: The framework services are to increase awareness of the enterprise’s technology architecture capabilities. DS built to search metadata associated with application services, data services, platform services, or infrastructure services is an example of framework service. The DSs differs in terms of what type of metadata can be searched for which kind of service. Governance Services: DSs deployed to ensure the policies and practices are the governance services. Most diversification to the security related services including role based entitlement are the participant of governance services. 5. Evaluating Velocity of an Enterprise The experimental evaluation is based on set of 62 DSs out of 304 services (includes functional architecture type services as well as industry segment specific services besides dedicated DSs). The services are built in Oracle SOA suite [24] that has internal capabilities to map and generate relationship with BP activities. 4 iterations of the development, updates, and deployment have been conducted for the following 7 BPs. The BP activities and DSs are derived based on severity of the BP requirements. Organizational Services: Organization culture has various impacts on the BP activities. DSs that offer common understanding of organization culture as well as corporate processes are the organizational services. Ordering and utilizing office supplies for different departments is an example of organizational service. In this example, DS differs in terms of accessibility of type of supplies to the particular department. BP# 1: Customer enrollment and registration BP# 2: Manage customer information, inquiry, and history BP# 3: Purchase order BP# 4: Payment processing and account receivables BP# 5: Invoicing BP# 6: Notification and acceptance of terms BP# 7: Account management Strategic Services: DSs participates in making a decision that impacts strategic direction and corporate goals are categorized as strategic services. Financial analysis based selection of marketing segments and budgeting based on available statistics of annual spending are the types of strategic services. Velocity of the enterprise is representation of the rapid changes and updates necessary to achieve the BP requirements. The changes can be achieved through updating or introducing either DS operations, DSs, BP activities, or sublevel BPs. Correspondingly, the velocity is based on four types of ratios as specified bellow. The ratios are representation of the level of change necessary to achieve goals of BP requirement. Conditional Services: Certain BP activities require special attention and business logic dedicated to particular condition. The DSs built, updated, and maintained to accommodate such scenarios are subject to this classification. Credit card with special privilege for purchases over allocated limit is an example of such DSs. DSs’ Ratio (DSR) = (Additional composite service / Total number of services) DS Operations’ Ratio (OPR) = (Additional accumulative number of DSs operations / Accumulative number of DSs operations) BP Activities’ Ratio (AR) = (Additional BP activities / Total number of BP activities) Sublevel BPs’ Ratio (SBR) = (Additional sublevel BPs / Total number of sublevel BPs) Automation Services: They are the services defined and utilized to introduce desired level of automation, yielding additional business value for new or existing BP activities. Typically, automation related services require stronger bonding and maturity at the BP activities. Service to send email notification for the approval versus the service for online approval is the classical example of such DSs. DSs can be associated with multiple categories. However, alias to the DS is utilized for the secondary category such that it can be independently monitored and audited. Optional DSs’ common header elements (or metadata) are introduced to capture the runtime metrics for the DSs. Following are the additional information that DSs’ provides at runtime for further evaluation. The velocity evaluation presented in Eq (1) also introduces impact factor corresponding to each ratio, that is, c (critical), h (high), m (medium), and l (low). The assigned values for the impact factors are c = 10, h = 7, m = 4, and l = 2 to indicate finite value for the severity of update. There is absolutely no constraint to revisit the allocation of 41 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org severity to update impact factors during subsequent iterations of updates to BP requirements and corresponding deployment cycle. It should be based on findings as well as severity of BP requirements in consideration. In Eq (1), #BPs represents total number of participant BPs to form DSs enabled enterprise (7 in this case). When there is a need to introduce or update sublevel BP due to BP requirement then it is considered critical (c) change to an enterprise. Whereas, update to or introduction of DS operation is considered lowest category of change, that is, low (l). As such there is no maximum limit set for the velocity, however, present deployment iteration’s velocity score can be considered as the baseline for subsequent iterations. The progressive values of velocity are indicated in Figure 2 for each iteration (1 through 4) pertaining to the 7 BPs in consideration. 6. Formulating DSs Maintainability Index (DSMI) There is no obvious solution to evaluate maintainability of DSs. The primary reason is due to the little to no effort for defining maturity model and standardization for DSs. SOA maturity models and governance are implied at more operational aspects of the functional architecture type services [30] and [13]. The other types of metrics presented in [1] and [32] to measure the agility irrespective of the maintainability concerns of DSs. The DSMI is an effort to compute and continuously monitor maintainability of DSs. Oracle SOA suite capabilities are utilized to monitor and log DSs. Service registry features are embraced to define, govern, and monitor SLAs as well as metadata associated with the DSs. VELOCITY = # BPs BP1 m DSR l OPR h AR c SBR (1) # BPs Table 1 provides implementation based analysis and computed velocity of 4th deployment iteration of BP requirements corresponding to the 7 BPs (as described above). Following are the acronyms utilized in Table 1. #DS: total number of participant DSs for the BP. #OPs: accumulative number of DSs’ operations involved. #As: total number of BP activities for the BP. #SBPs: total number of sublevel BPs of the BP. #A-CS: sum of new and updated DSs to the BP in iteration 4. #A-OPs: sum of new and updated number of DSs’ operations introduced to the BP in iteration 4. #A-A: sum of new and updated BP activities introduced to the BP in iteration 4. #A-SBPs: sum of new and updated sublevel BPs introduced to the BP in iteration 4. DSs’ operations, DSs, BP activities, and sublevel BPs that are being reused across multiple BPs are counted at each and every instance for the purpose of accuracy to evaluate velocity. 6.1 Paradigms to Derive Inverted DSMI The paradigms to formulate DSMI are described below for each type of DSs. Business continuity (BUC): It is to determine whether the introduced or updated DSs are able to continue the day-today business activities after the deployment (or iteration). The evaluation criterion for BUC paradigm is to monitor the number of unique support tickets created for type of DSs in context. For example, new customer registration is providing errors due to inaccuracies in validation of customer account number and/or customer identification. The inverted ratio for BUC specific to the set of DSs associated with the DS type is derived below. Table 1: Velocity of the enterprise in iteration 4 BP# 1 #DSs (#A-CSs) 7(0) # OPs (#A-OPs) 20(2) #As (#A-A) 8(1) # SBPs (#A-SBPs) 2(0) iBUC<DS type> = (# of unique support tickets by the customer / #DSs deployed for <DS type>) 2 12(3) 28(7) 15(0) 3(0) 3 18(4) 42(7) 22(2) 5(1) 4 8(2) 15(3) 15(2) 3(0) 5 5(1) 12(2) 10(1) 3(0) 6 3(0) 8(1) 7(0) 1(0) 7 9(2) 16(3) 14(1) 2(0) Operational risk (ORI): Operational risks are basically to evaluate the DS level continuation of the enterprise operations. Typically, it is traced by the number of failures occurred for the DSs in the production cycle of present deployment iteration. The specific example of change purchase order request DS failed due to unambiguous condition occurred within the dedicated DSs. The inverted ratio for ORI specific to the set of DSs associated with the DS type is derived below. VELOCITY (of Iteration 4) = 1.52 42 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org an example of extendibility of DSs associated with payment processing and account receivable BP. The inverted ratio for ECI specific to the set of DSs associated with the DS type is derived below. iORI<DS type> = (# of unique operational failures/ (#DSs deployed for <DS type>) The ratio of oRIS is being generated by comparing the failures with previous deployment iteration. The DSs header contains probability of failures and it is being automated at some extend to gain indicative operational risk at runtime (as stated in Section 4). iECI<DS type> = (# of alternate BP flows accustomed in DSs of <DS Type> / #DSs deployed for <DS type>) If “n” stands for the number of DS types identified in an enterprise (it is 10 in this case based on Section 4) then inverted DSMI can be computed based on Eq. (2). #Paradigms (number of paradigms) to impact the DSMI is 5 as described above. SLA Factorization (SPR): Scalability, reliability, and performance (SPR) are being bundled to evaluate SLA factorization. The SLAs defined in consideration of desired SPR for each type of DSs are configured and monitored. The SPR is identified based on the number of violations by the particular category of DSs in the present deployment iteration. The 4 seconds delay (when SLA is set for maximum 3 seconds) in sending order confirmation to vendor for specific product due to the heavy traffic is an example of SLA violation. The inverted ratio for SPR specific to the set of DSs associated with the DS type is derived below. Inverted DSMI = (1 / DSMI) = [( 1 iBUC ) / n][( 1 iORI ) / n][( 1 iSPR) / n][( 1 iCOS ) / n][( 1 iECI ) / n] (2) # Paradigms n n n n n Table 1 below presents the DSMI computed in the iteration 4 for the identified and deployed 7 BPs (as described in Section 5). iSPR<DS type> = (# of unique SPR specific SLA violations/ (#DSs deployed for <DS type>) Table 2: DSMI in iteration 4 Paradigm iBUC iORI iSPR iCOS iECI Competency (6) 0.33 0.83 0.5 0.5 0.67 Relationship (12) 0.25 0.67 0.5 1.5 0.5 Collaboration (4) 0.25 0 0.25 0.5 0.25 Common (7) 0.29 0.14 0.42 2 0.29 Framework (8) 0.5 0.25 0.75 0.5 0.38 Governance (6) 0.33 0.5 0.33 1.5 0.83 Organizational (7) 0.29 0.14 0.42 0.71 0.86 iCOS<DS type> = (# of BP activities utilizing DSs of <DS Type> / #DSs deployed for <DS type>) Strategic (7) 0.14 0 0.14 1 0.42 Conditional (5) 0.6 0.8 0.4 0.4 0.2 Extendibility and Continuous Improvements (ECI): Extensibility and continuous improvement of the DSs are evaluated based on customization required to accomplish BP requirements. It is computed considering the number of additional custom modeling as well as implementation needed in context of BP activity and enterprise entity. The primary objective is, whether respective DSs are able to accommodate these customizations within the dilemma of their dependencies with existing enterprise entities. If the payment is not received within 6 months then it needs to be sent for collection and vendor also needs to be notified, is Automation (3) 0.33 0.67 1.67 0.67 2 Consistency (COS): Consistency can be evaluated at many different aspects. The primary objective of this criterion is to assess scope of the DS across multiple BP activities. Due to the BPs requirements, specification of the DS needs to incorporate high level interactions with enterprise entities and underneath events of BP activities. The consistency of DS is being derived based on the number of BP activities utilizing the specific type of DSs in considerations. The most prominent example is order delivery confirmation and status needs to be sent to customer, vendor, and account receivables. The inverted ratio for COS specific to the set of DSs associated with the DS type is derived below. DS Type (# of DSs) Actual DSMI (of Iteration 4) = 1.76 6.2 Analysis and Observations of Evaluation Figure 2 provides the progress of velocity and DSMI through iteration 4 for the 7 BPs deployed, advanced, and monitored. The finite numbers indicate the significant reduction in velocity over the iterations. 58% reduction in velocity (of deployment iteration 4) compare to iteration 3. 43 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org and placing DSs. The categorization and corresponding implementation for BP requirements into the DSs are identified and implied. Formulae to evaluate velocity of enterprise and assessment criteria to monitor maintainability of deployed DSs in terms of index are illustrated with an example implementation and validated in number of actual deployment iterations. The graph also indicates increase in DSMI over the iterations. The DSMI (of deployment iteration 4) is improved by 21% compare to iteration 3. The result directly illustrates that continuous monitoring and improvements in terms of reducing the number of issues reported by the business users, immediate resolutions to causes of services’ failures, accurate modeling of DSs with respective to the BP requirements, and precisions in test scenarios decreases the velocity of enterprise and stabilizes the DSMI. The rationalization achieved utilizing the methodology to derive and place principles of DSs increases consistency and predictability across multiple units as well as entities of an enterprise. The measurable implications due to changes in BP requirements and assessable maintainability are accomplished due to the classification and evaluation methodologies of DSs. The subsequent step is to determine more granular level of DSs types that can be leveraged in multifaceted BP scenarios. The underneath primary goal remains intact, that is, to evolve, retain, and stabilize maintainability of DSs. Acknowledgments Vikas Shah wishes to recognize Wipro Technologies’ Connected Enterprise Services (CES) sales team to support the initiative. Special thanks to Wipro Technologies’ Oracle practice for providing opportunity of implying conceptually identified differentiated principles, types, and measurements in 4 different iterations. Fig. 2 Computed velocities and DSMI for all deployment iterations in production. Essentially, it concludes that more number of BP activities utilizing single DS and more number of alternate path inclusion to single DS decreases the level of maintainability of DSs, however, it increases the consistency and extendibility of the DSs. Contrarily, introducing more number of DSs also increases additional level of SLAs’ associations and uncertainties, however, introduces increased level of flexibility and agility in an enterprise. It is a trade-off that enterprise has to decide during the assessment of DSs architecture (2nd step described in Section 3 Figure 2). References [1] [2] [3] 7. Conclusions [4] The perception of SOA is receiving wide acceptance due to the ability of accustom and respond to BP related requirements and changes providing operational visibilities to an enterprise. DSs are the means to accommodate uncertainties of BPs such that an enterprise may able to gain acceptable level of agility and completeness. 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Vishal Dwivedi and Naveen Kulkarni, “A Model Driven Service Identification Approach for Process Centric Systems,” In: 2008 IEEE Congress on Services Part II, pp.65-72, 2008. Xie Zhengyu, Dong Baotian, and Wang Li, “Research of Service Granularity Base on SOA in Railway Information Sharing Platform,” In: Proceedings of the 2009 International Symposium on Information Processing (ISIP’09), pp. 391395, August 21-23, 2009. Vikas S Shah received the Bachelor of Engineering degree in computer engineering from Conceicao Rodrigues College of Engineering, University of Mumbai, India in 1995, the M.Sc. degree in computer science from Worcester Polytechnic Institute, MA, USA in 1998. Currently he is Lead Architect in Connected Enterprise Services (CES) group at Wipro Technologies, NJ, USA. He has published several papers in integration architecture, realtime enterprises, architecture methodologies, and management approaches. He headed multiple enterprise architecture initiatives and research ranging from startups to consulting firms. Besides software architecture research and initiatives, he is extensively supporting pre-sales solutions, risk management methodologies, and service oriented architecture or cloud strategy assessment as well as planning for multinational customers. 45 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org A comparative study and classification on web service security testing approaches Azadeh Esfandyari Department of Computer, Gilangharb branch, Islamic Azad University, Gilangharb, Iran [email protected] achieve reliable Web services, which can be integrated into compositions or consumed without any risk in an open network like the Internet, more and more software development companies rely on testing activities. In particular, security testing approaches help to detect vulnerabilities in Web services in order to make them trustworthy. The rest of paper is organized as follows: Section II presents an overview and a classification of web service testing approaches. Section III summarizes web service security testing approaches and issues. Finally, section IV gives a conclusion of the paper. Abstract Web Services testing is essential to achieve the goal of scalable, robust and successful Web Services especially in business environment where maybe exist hundreds of Web Services working together. This Relatively new way of software development brings out new issues for Web Service testing to ensure the quality of service that are published, bound, invoked and integrated at runtime. Testing services poses new challenges to traditional testing approaches. Dynamic scenario of Service Oriented Architecture (SOA) is also altering the traditional view of security and causes new risks. The great importance of this field has attracted the attention of researchers. In this paper, in addition of presenting a survey and classification of the main existing web service testing approaches, web service security testing researches and their issues are investigated. 2. Overview and a classification of web service testing approaches Keywords: web service security testing, WSDL The Web Services world is moving fast, producing new specification all the time and different applications, and hence introducing more challenges to develop more adequate testing schemes. The challenges stem mainly from the fact that Web Services applications are distributed applications with runtime behaviors that differ from more traditional applications. In Web Services, there is a clear separation of roles between the users, the providers, the owners, and the developers of a service and the piece of software behind it. Thus, automated service discovery and ultra-late binding mean that the complete configuration of a system is known only at execution time, and this hinder integration testing [2]. To have an overview of web service testing approaches I use the classification proposed by [2]. But it seems that this classification is not sufficient for categorizing all existing approaches therefore new classification is introduced. In [2] the existing web service testing approaches are classified to 4 classes by excluding the approaches that are based on formal method and data gathering: WSDL-Based Test Case Generation Approaches Mutation-Based Test Case Generation Approaches Test Modeling Approaches XML-Based Approaches All Mutation-Based test case generation approaches that referred to in [2] like [3, 4] are based on WSDL and can placed in first class. Also there are approaches that in addition to considering WSDL specification use other scenarios to cope with limitation of WSDL specification 1. Introduction The Web Services are modular, self-described and selfcontained applications. With the open standards, Web Services enable developers to build applications based on any platform with any component modular and any programming language. More and more corporations now are exposing their information as Web Services and what’s more, it is likely that Web Services are used in mission critical roles, therefore performance matters. Consumers of web services will want assurances that Web Services won’t fail to return a response in a certain time period. So the Web Services testing is more important to meet the consumers’ needs. Web Services’ testing is different from traditional software testing. In addition, traditional testing process and tools do not work well for testing Web Services, and therefore, testing Web Services is difficult and poses many challenges to traditional testing approaches due to the above mentioned reason and mainly because Web Services are distributed applications with numerous runtime behaviors. Generally, there are two kinds of Web Services, the Web Services are used in Intranet and the Web Services are used in Internet. Both of them face the security risk since message could be stolen, lost, or modified. The information protection is the complex of means directed on information safety assuring. In practice it should include maintenance of integrity, availability, confidentiality of the information and resources that used for data input, saving, processing and transferring [1]. To 46 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org based test case generation so introduction new category is seemed necessary. The proposed classification is: WSDL-Based Test Case Generation Approaches Test Modeling Approaches XML-Based Approaches Extended Test Case Generation Approaches semantical aspects which are highly critical for service availability testing, unlike other approaches that focus on syntactical correctness, to be designed at an early stage to drive the product development process and to help uncover failures prior to deployment of services [2]. Tsai et al. [9] present a Web Services testing approach based on a stochastic voting algorithm that votes on the outputs of the Web Service under test. The algorithm uses the idea of k-mean clustering to handle the multidimensional data with deviations. The heuristics is based on local optimization and may fail to find the global optimal results. Furthermore, the algorithm assumes that the allowed deviation is known, which may be hard to determine because the deviation is application dependent. 2.1 WSDL-Based Test Case Generation Approaches These approaches essentially present solution for generating test cases for web services based only on Web Services Description Language (WSDL).Research activities in this category are really extensive and not included in this paper. Two WSDL approaches is introduced in following. 2.3 XML-Based Approaches Hanna and Munro in [5] present solution for test cases generation depending on a model for the XML schema datatypes of the input message parameters that can be found in WSDL specification of the Web Service under test. They consider the role of application builder and broker in testing web services. This framework use just boundary value testing techniques. Tsai et al. [10] proposed an XML-based object-oriented (OO) testing framework to test Web Services rapidly. They named their approach Coyote. It consists of two parts: test master and test engine. The test master allows testers to specify test scenarios and cases as well as various analyses such as dependency analysis, completeness and consistency, and converts WSDL specifications into test scenarios. The test engine interacts with the Web Services under test, and provides tracing information. The test master maps WSDL specifications into test scenarios, performs test scenarios and cases generation, performs dependency analysis, and completeness and consistency checking. A WSDL file contains the signatures specification of all the Web Services methods including method names, and input/output parameters, and the WSDL can be extended so that a variety of test techniques can be used to generate test cases. The test master extracts the interface information from the WSDL file and maps the signatures of Web Services into test scenarios. The test cases are generated from the test scenarios in the XML format which is interpreted by test engine in the second stage. Di Penta et al. [11] proposed an approach to complement service descriptions with a facet providing test cases, in the form of XML-based functional and nonfunctional assertions. A facet is a (XML) document describing a particular property of a service, such as its WSDL interface. Facets to support service regression testing can either be produced manually by the service provider or by the tester, or can be generated from unit test cases of the system exposed as a service. Mao in [6] propose two level testing framework for Web Service-based software. In service unit level, combinatorial testing method is used to ensure single service’s reliability through extracting interface information from WSDL file. In system level, BPEL specification is converted into state diagram at first, and then state transition-based test cases generation algorithm is presented. Obviously the researches that generate web service test case from WSDL by using various testing techniques like black box and random testing techniques and so on are placed in this category. 2.2 Test Modeling Approaches Model-based testing is a kind of black-box testing, where these experiments are automatically generated from the formally described interface specification, and subsequently also automatically executed [7]. Frantzen et al. [7] discuss on a running example how coordination protocols may also serve as the input for Model-Based Testing of Web Services. They propose to use Symbolic Transition Systems and the underlying testing theory to approach modelling and testing the coordination. Feudjio and Schieferdecker in [8] introduced the concept of test patterns as an attempt to apply the design pattern approach broadly applied in object-oriented software development to model-driven test development. Pattern driven test design effectively allows tests targeting 2.4 Extended Test Case Generation Approaches Because of weak support of WSDL to web services semantical aspect some approaches don't confine themselves only to WSDL-Based Test Case Generation. 47 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Graphical User Interface (GUI), where the test cases are written in XML files and the results are shown in HTML and XML files [15]. Damiani et al. [12] in order to guarantee the quality of the given services propose collaborative testing framework where different part participate in. They proposed a novel approach that uses a third party certifier as a trusted entity to perform all the needed test on behalf of the user and certify that a particular service has been tested successfully to satisfy the user's needs. The open model scenario is a way to overcome the limitations of WSDL specification based test cases generation [12]. Since the service source code is generally not available, the certifier can gain a better understanding about the service behavior starting from its model. The benefit of such strategy is to allow the certifier to identify the critical areas of the service and therefore design test cases to check them [12]. 3. Web service security testing overview and related work Web services play an important role for the future of the Internet, for their flexibility, dynamicity, interoperability, and for the enhanced functionalities they support. The price we pay for such an increased convenience is the introduction of new security risks and threats, and the need of solutions that allow to select and compose services on the basis of their security properties [16]. This dynamic and evolving scenario is changing the traditional view of security and introduces new threats and risks for applications. As a consequence, there is the need of adapting current development, verification, validation, and certification techniques to the SOA vision [17]. To achieve reliable Web services, which can be integrated into compositions or consumed without any risk in an open network like the Internet, more and more software development companies rely on software engineering, on quality processes, and quite obviously on testing activities. In particular, security testing approaches help to detect vulnerabilities in Web services in order to make them trustworthy. Concerning, the Web service security testing few dedicated works have been proposed. In [18], the passive method, based on a monitoring technique, aims to filter out the SOAP messages by detecting the malicious ones to improve the Web Service’s availability. Mallouli et al. also proposed, in [19], a passive testing method which analyzes SOAP messages with XML sniffers to check whether a system respects a policy. In [20], a security testing method is described to test systems with timed security rules modelled with Nomad. The specification is augmented by means of specific algorithms for basic prohibition and obligation rules only. Then, test cases are generated with the "TestGenIF" tool. A Web Service is illustrated as an example. In [21] a security testing method dedicated for stateful Web Services is proposed. Security rules are defined with the Nomad language and are translated into test purposes. The specification is completed to take into account the SOAP environment while testing. Test cases are generated by means of a synchronous product between test purposes and the completed specification. 2.5 Web service testing tools Many tools have been implemented for testing Web Services. Next subsections describe briefly the three selected tools. • SoapUI Tool This tool is a Java based open source tool. It can work under any platform provided with Java Virtual Machine (JVM). The tool is implemented mainly to test Web Services such as SOAP, REST, HTTP, JMS and other based services. Although SoapUI concentrates on the functionality, it is also consider performance, interoperability, and regression testing [13]. • PushToTest Tool One of the objectives of this open source tool is to support the reusability and sharing between people who are involved in software development through providing a robust testing environment. PushToTest primarily implemented for testing Service Oriented Architecture (SOA) Ajax, Web applications, Web Services, and many other applications. This tool adopts the methodology which is used in many reputed companies. The methodology consists of four steps: planning, functional test, load test, and result analysis. PushToTest can determine the performance of Web Services, and report the broken ones. Also, it is able to recommend some solutions to the problems of performance [14]. • WebInject Tool This tool is used to test Web applications and services. It can report the testing results in real time, and monitor applications efficiently. Furthermore, the tool supports a set of multiple cases, and has the ability to analyze these cases in reasonable time. Practically, the tool is written in Perl, and works with the platforms which have Perl interpreter. The architecture of WebInject tool includes: WebInject Engine and Some researchers (e.g., ANISETTI et al. [17]) focused on security certification. They believe that certification techniques can play a fundamental role in the servicebased ecosystem. However, existing certification techniques are not well-suited to the service scenario: they usually consider static and monolithic software, provide certificates in the form of human-readable statements, and 48 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Four classes are introduced for web service testing approaches. By considering this classification when security is concerned, the classes that are only based on WSDL specifications can't be useful for security testing. Since ignoring WSCL and implementation details doesn't allow the definition of accurate attack models and test cases. Because of the fourth class abstraction, it can include approaches that by complete modeling of service enable themselves to produce fine-grained test cases that will be used to certify the security property of service(e.g., ANISETTI et al. [16]) . Although some security concepts aren't taken into account in [16] (for instance reliability) and the level of complexity of its processes has increased, but it seems that this is the most comprehensive approach in web service security certification area. consider systemwide certificates to be used at deployment and installation time. By contrast, in a service-based environment, we need a certification solution that can support the dynamic nature of services and can be integrated within the runtime service discovery, selection, and composition processes [22] To certify that a given security property is holed by its service, two main types of certification processes are of interest: test-based certification and model-based certification. According to Damiani et al. [23], test-based certification is a process producing evidence-based Proofs that a (white- and/or black-box) test carried out on the software has given a certain result, which in turn shows that a given high-level security property holds for that software. Model-based certification can provide formal proofs based on an abstract model of the service (e.g., a set of logic formulas or a formal computational model such as a finite state automaton). ANISETTI et al. [16] propose a test-based security certification scheme suitable for the service ecosystem. The scheme is based on the formal modeling of the service at different levels of granularity and provides a modelbased testing approach used to produce the evidence that a given security property holds for the service. The proposed certification process is carried out collaboratively by three main parties: (i) a service provider that wants to certify its services; (ii) a certification authority managing the overall certification process; and (iii) a Lab accredited by the certification authority that carries out the property evaluation. Service model generated by the certification authority using the security property and the service specifications is defined at three level of granularity: WSDL-based model, WSCL-based model and implementation-based model. The certification authority sends the Service model together with the service implementation and the requested security property to the accredited Lab. The accredited Lab generates the evidence needed to certify the service on the basis of the model and security property and returns it to the certification authority. If the evidence is sufficient to prove the requested property the certification authority awards a certificate to the service, which includes the certified property, the service model, and the evidence. They also propose matching and comparison processes that return the ranking of services based on the assurance level provided by service certificates. Because of supporting the dynamic comparison and selection of functionally equivalent services, the solution can be easily integrated within a service-based infrastructure. References [1] Li, Y., Li, M., & Yu, J. (2004). Web Services Testing, the Methodology, and the Implementation of the AutomationTesting Tool. In Grid and Cooperative Computing (pp. 940-947). [2] Ladan, M. I. (2010). Web services testing approaches: A survey and a classification. In Networked Digital Technologies (pp. 70-79). [3] Siblini, R., & Mansour, N. (2005). Testing web services. In Computer Systems and Applications, 2005. The 3rd ACS/IEEE International Conference on (p. 135). [4] Andre, L., & Regina, S. (2009). V.: Mutation Based Testing of Web Services.IEEE Software. [5] Hanna, S., & Munro, M. (2007, May). An approach for specification-based test case generation for Web services. In Computer Systems and Applications, 2007. AICCSA'07. IEEE/ACS International Conference on (pp. 16-23). [6] Mao, C. (2009, August). A specification-based testing framework for web service-based software. In Granular Computing, 2009, GRC'09. IEEE International Conference on (pp. 440-443). [7] Frantzen, L., Tretmans, J., & de Vries, R. (2006, May). Towards model-based testing of web services. In International Workshop on Web Services–Modeling and Testing (WS-MaTe 2006) (p. 67). [8] Feudjio, A. G. V., & Schieferdecker, I. (2009). Availability testing for web services. [9] Tsai, W. T., Zhang, D., Paul, R., & Chen, Y. (2005, September). Stochastic voting algorithms for Web services group testing. In Quality Software, 2005.(QSIC 2005). Fifth International Conference on (pp. 99-106). [10] Tsai, W. T., Paul, R., Song, W., & Cao, Z. (2002). Coyote: An xml-based framework for web services testing. In High Assurance Systems Engineering, 2002. Proceedings. 7th IEEE International Symposium on (pp. 173-174). [11] Di Penta, M., Bruno, M., Esposito, G., Mazza, V., & Canfora, G. (2007). Web services regression testing. In Test and Analysis of web Services (pp. 205-234). [12] Damiani, E., El Ioini, N., Sillitti, A., & Succi, G. (2009, July). Ws-certificate. InServices-I, 2009 World Conference on (pp. 637-644). [13] "SoapUI tool" , http://www.SoapUI.org. [14] "PushToTest tool", http://www.PushToTest.com. 4. Conclusions This paper had a review on main issue and related work on Web Service testing and Web Service security testing. 49 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [15] "WebInject", http://www.WebInject.org/. [16] Anisetti, M., Ardagna, C. A., Damiani, E., & Saonara, F. (2013). A test-based security certification scheme for web services. ACM Transactions on the Web (TWEB), 7(2), 5. [17] Anisetti, M., Ardagna, C., & Damiani, E. (2011, July). Finegrained modeling of web services for test-based security certification. In Services Computing (SCC), 2011 IEEE International Conference on (pp. 456-463). [18] Gruschka, N., & Luttenberger, N. (2006). Protecting web services from dos attacks by soap message validation. In Security and privacy in dynamic environments (pp. 171182). [19] Mallouli, W., Bessayah, F., Cavalli, A., & Benameur, A. (2008, November). Security rules specification and analysis based on passive testing. In Global Telecommunications Conference, 2008. IEEE GLOBECOM 2008. IEEE (pp. 16). [20] Mallouli, W., Mammar, A., & Cavalli, A. (2009, December). A formal framework to integrate timed security rules within a TEFSM-based system specification. InSoftware Engineering Conference, 2009. APSEC'09. Asia-Pacific (pp. 489-496). [21] Salva, S., Laurençot, P., & Rabhi, I. (2010, August). An approach dedicated for web service security testing. In Software Engineering Advances (ICSEA), 2010 Fifth International Conference on (pp. 494-500). [22] Damiani, E., & Manã, A. (2009, November). Toward ws-certificate. InProceedings of the 2009 ACM workshop on Secure web services (pp. 1-2). [23] Damiani, E., Ardagna, C. A., & El Ioini, N. (2008). Open source systems security certification. Springer Science & Business Media. 50 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Collaboration between Service and R&D Organizations – Two Cases in Automation Industry Jukka Kääriäinen1, Susanna Teppola1 and Antti Välimäki2 1 VTT Technical Research Centre of Finland Ltd. Oulu, P.O. Box 1100, 90571, Finland {jukka.kaariainen, susanna.teppola}@vtt.fi 2 Valmet Automation Inc. Tampere, Lentokentänkatu 11, 33900, Finland [email protected] services? In this article, the objective is not to describe the service development process, but rather to try to understand and collect industrial best practices that increase the collaboration and transparency between the Service and R&D organizations so that customers can be serviced better and more promptly. Abstract Industrial automation systems are long-lasting multitechnological systems that need industrial services in order to keep the system up-to-date and running smoothly. The Service organization needs to jointly work internally with R&D and externally with customers and COTS providers so as to operate efficiently. This paper focuses to Service – R&D collaboration. It presents a descriptive case study of how the working relationship between Service and R&D organizations has been established in a two example industrial service cases (upgrade and audit cases). The article reports the collaboration practices and tools that have been defined for these industrial services. This research provides, for other companies and research institutes that work with industrial companies, practical real-life cases of how Service and R&D organizations collaborate together. Other companies would benefit from studying the contents of the cases presented in this article and applying these practices in their particular context, where applicable. Keywords: Automation systems, Industrial service, Lifecycle, Transparency, Collaboration. This article intends to discuss the collaboration between the Service and R&D organizations using two cases that provide practical examples about the collaboration, i.e. what the collaboration and transparency between the Service and R&D organizations mean in a real-life industrial environment. In addition, the paper reports what kind of solutions the company in the case study uses to effectuate the collaboration. The paper is organized as follows. In the next section, background and need for Service and R&D collaboration are stated. In section 3, the case context and research process is introduced. In section 4, two industrial service processes are introduced that are cases for analyzing Service and R&D collaboration. In section 5, the cases are analyzed from Service and R&D collaboration viewpoint. Finally, section 6, discusses the results and draws up the conclusions. 1. Introduction Industrial automation systems are used in various industrial segments, such as power generation, water management and pulp and paper. The systems comprise HW and SW sub-systems that are developed in-house or COTS (Commercial Off-The-Shelf) components. Since these systems have a long useful life, the automation system providers offer various different kinds of lifecycle services for their customers in order to keep their automation systems running smoothly. 2. Background In the digital economy, products and services are linked more closely to each other. The slow economic growth during recent years has boosted the development of product-related services even more – they have brought increasing revenue for the manufacturing companies in place of traditional product sales [3, 4]. The global market for product and service consumption is constantly growing [5]. In 2012, the overall estimate for service revenues accrued from automation products like DCS, PLC, Integrated service/product development has been studied quite a bit, e.g. in [1, 2]. However, there is less information available how in practice the needs of the Service organization could be taken into account during product development. What kind of Service/R&D collaboration could improve the quality and lead time of the industrial 51 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org based on a generic product platform, and a new version of this product platform is released annually. Automation system vendors are also using HW and SW COTS components in their systems, for instance, third-party operating systems (e.g. Windows). Therefore, automation systems are dependent on, for instance, the technology roadmaps of operating system providers. The (generic) main sub-systems in an automation system include: Control Room, Engineering Tools, Information Management and Process Controllers. SCADA, etc. amounted to nearly $15 billion [6]. Customers are more and more interested in value-added services compared to the basic products itself. Therefore, companies and business ecosystems need the ability to adapt to the needs of the changing business environment. The shift from products to services has been taking place in the software product industry from 1990 onwards [7]. The importance of service business has been understood for a while, but more systematic and integrated product and service development processes are needed [8]. During recent years the focus has shifted towards understanding the customer’s needs and early validation of the success of developed services [9]. Furthermore, the separation of service and R&D organization may cause communication problems that need to be tackled with new practices and organizational units [10]. Engineering tools are used to configure the automation system so as to fit the customer’s context. This includes, for instance, the development of process applications and related views. Automation systems have a long life and they need to be analyzed, maintained and updated, if necessary. Therefore, the case company offers, for instance, upgrade and audit services to keep the customers’ automation systems up-to-date. Each update will be analyzed individually so as to find the optimal solution for the customer based on the customer’s business needs. Service operation is highly distributed since the case company has over 100 sales and customer service units in 38 countries serving customers representing various industrial segments in Europe, Asia, America, Africa and Australia. Technical deterioration (technology, COTS, standards, etc.) of the systems that have a long lifetime (such as automation systems) is a problem in industry. The reliability of technical systems will decrease over time if companies ignore industrial services. “For a typical automation/IT system, only 20-40 percent of the investment is actually spent on purchasing the system; the other 60-80 percent goes towards maintaining high availability and adjusting the system to changing needs during its life span” [11]. This is huge opportunity for vendors to increase their industrial service business. Automation system providers offer their automation systems and related industrial services in order to keep customer’s industrial processes running smoothly. These industrial services need to be done efficiently. Therefore, there should be systematic and effective service processes with supporting IT systems in global operational environment. Furthermore, there should be collaboration practices with R&D and Service organization that systems can be efficiently serviced and are service friendly. This all requires deeper understanding how Service and R&D organizations should operate to enable this collaboration. Because of the demands of customer-specific tailoring, there are many customer-specific configurations (i.e. the customer-specific variants of an automation system) in the field containing sub-systems from different platform releases (versions). Therefore, the Service organization (the system provider) needs to track each customer configuration of an automation system and detect what maintenance, optimization, upgrades are possible for each customer to keep the customer’s automation solutions running optimally. Case company aims at better understand collaboration between Service organization and R&D organization. For other companies and research institutes this research provides a descriptive case study how the collaboration between Service and R&D organizations have been established in a two example service case (upgrade and audit cases). Therefore, the research approach is bottom-up. These cases were selected into this study since the company personnel that work in this research project have in-depth knowledge about these services. We first studied these two service processes and then analyzed what kinds of activities can be found to enable the transparency between service and R&D organizations in these cases. We selected this approach since each industrial service seems to have its own needs for collaboration and therefore you first need to understand the service process itself. We have 3. Case context and research process This work was carried out within the international research projects Varies (Variability in Safety-Critical Embedded Systems) [12] and Promes (Process Models for Engineering of Embedded Systems) [13]. The case company operates in the automation systems industry. The company offers automation and information management application networks and systems, intelligent field control solutions, and support and maintenance services. The case focuses on the automation system product sector and includes the upgrade and audit service. Typically, the customer-specific, tailored installation of the system is 52 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org been utilized in order to identify the interfaces between service and R&D organizations. adapted the approach defined by Charalampidou et al. [14] as a frame for process descriptions. The research has been done as follows: 4.1 Case 1: Upgrade–service 1. 2. 3. 4. Upgrade–service process description was composed using company interviews and workshops (case 1). Audit–service process description was composed using company interviews and workshops (case 2). Case analysis was performed that combined case 1 and 2 and additional interviews/workshops were held to understand service/R&D collaboration behind the service processes. Two persons that work in service-R&D interface in case 1 and case 2 were interviewed and the results were discussed. Finally, the results of the case 1, case 2 and case analysis were reviewed and modified by the representatives of case company. This section presents the Upgrade-service process (Fig. 1). Upgrade-service is a service that will be provided for a customer to keep their automation systems up and running. The detailed description and demonstration of Upgradeservice process has been presented in [15]. Phases are divided into activities that represent collections of tasks that will be carried out by the workers (e.g. Service Manager). One worker has the responsibility (author) for the activity, and other workers work as contributors. Activities create and use artefacts that will be retrieved from or stored in tools (information systems). The upgrade service process is divided into six activities. The first four, form the Upgrade Planning process. The last two represent subsequent steps, as the implementation of upgrade and subsequent follow up. This case focuses to Upgrade planning–phase of the Upgrade-service process. The process contains a sequence of activities to keep the presentation simple, even though in real-life, parallelism and loops/iterations are also possible. For instance, new customer needs may emerge during price negotiations that will be investigated in a new upgrade planning iteration. 4. Industrial cases Industrial automation systems are used in various industrial segments, such as power generation, water management and pulp and paper production. The systems comprise HW and SW sub-systems that are in-house developed or COTS (Commercial Off-The-Shelf) components. Since these systems have a long lifetime, the automation system providers offer different kinds of industrial services for their customers in order to keep their automation systems running smoothly. “Identify upgrade needs” activity: The process starts with the identification of upgrade needs. The input for an upgrade need may come from various sources, for instance, directly from customer, from a service engineer working on-site at the customer’s premises, from component end-of-life notification, etc. The Service Manager is responsible for collecting and documenting upgrade needs originating from internal or external sources. In this article, we present two cases related to the industrial services that both are the sub-processes of the maintenance main process. The first is Upgrade-service and the second is Audit-service. These cases represent process presentations that have been created in cooperation with the case company in order to document and systematize their service processes. These process descriptions have 53 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org NOTATION PROCESS ACTIVITY ARTEFACT PHASE Maintenance TOOL CONNECTOR Upgrade service Implementation & Follow-up Service manager Customer Service staff 3 Analyse the system / compose LC plan 2 Identify installed system Upgrade needs Service manager Customer 4 Communicate / negotiate Service manager Customer Service staff Service staff Implement upgrades according to plans Re-evaluate upgrade needs Lifecycle Plan Lifecycle report Installed Reports Lifecycle Services Service manager Customer R&D Service manager Service staff 1 Identify upgrade needs Engineering & Maintenance AUTHOR CONTRIBUTOR COMPOSITE ARTEFACT Upgrade Planning Operator Interface CREATE / STORE USE / RETRIEVE Installation information System / service offering ”Tell me your configuration” Life cycle rules Information Management & Web Reports Office Network Router 100 Mbit/s Network Architecture 100 Mbit/s Switched Ethernet PCS PCS BU/ AL P 1,2 Interfaces to: - PLC - DCS 0- mV 100 10deg 50 - QCS Distributed I/O’s Centralized I/O’s HART Plug-in Customer extranet Installation information Installed Base Automation system Fig. 1 Description of the Upgrade Planning Process. “Negotiations” activity: In the “Negotiations” activity, the service manager modifies the lifecycle plan based upon the maintenance budgets and downtime schedules of the customer. Customer extranet is the common medium for vendor and customer to exchange lifecycle plans and other material. The final lifecycle plan presents the life cycle of each part of the system, illustrating for a single customer what needs to be upgraded and when, and at what point in time a larger migration might be needed. The plan supports the customer in preparing themselves for the updates, for instance by predicting costs, schedules for downtimes, rationale for management, etc. Based on the negotiations and offer, the upgrade implementation starts according to contract. Additionally, the Service Manager is responsible for periodically re-evaluating the upgrade needs. “Identify installed system” activity: The service manager is responsible for carrying out “Identify installed system” activity. In this activity, the customer’s automation system configuration information (i.e. customer-specific installed report) is retrieved from the InstalledBase tool. The information is collected automatically from the automation system (automatically via a network connection with the customer’s automation system) and manually by a site visit, if needed. The updated information is stored in the InstalledBase tool. Analyze the system/compose LC (lifecycle) plan” activity: In the “Analyze the system/compose LC (lifecycle) plan” activity service manager is responsible for analyzing the instant and future upgrade needs for the customer’s automation system. The InstalledBase tool contains lifecycle plan functionality. This means that the tool contains some lifecycle rules related to the automation systems. The lifecycle rules are composed by a product manager who works in service interface working in collaboration with R&D organization. The service manager generates a lifecycle report from the InstalledBase tool and starts to modify it based on negotiations with the customer. 4.2 Case 2: Audit–service This section presents the Audit-service process (Fig. 2). Audit-service is used to determine the status of the automation system or equipment. Systematic practices/process and tools to collect the information allow repeatable and high-quality service that forms basis for subsequent services. Audit-service might launch, for instance, upgrade, optimizations, training –services. Again, 54 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org audit, customer contact/team, customer’s arrangements to ensure successful audit (availability of key persons during audit, data analysis and reporting/presentation, visits, remote connections, safety/security), schedule, resources and reporting/presentation practices, etc. Furthermore, service staff documents the audit plan and makes it visible for customer. as in Upgrade-service–case process description, phases are divided into activities that represent collections of tasks that will be carried out by the workers (e.g. Service Manager). One worker has the responsibility (author) for the activity, and other workers work as contributors. Activities create and use artefacts that will be retrieved from or stored in tools (information systems). The Auditservice process is divided into five activities. Office Research -activity: The purpose of Office Research is to carry out audit activities that can be done remotely. In this activity service staff collects remote diagnostics according to audit checklist. They further collect information about customerspecific product installation. The output of the activity is the data that is ready for data analysis. Plan audit -activity: This activity is used to identify, agree and document scope and needs for audit. This enables systematic audit. The planning starts when there are a demand for service or e.g. service agreement states that the audit will be done periodically. Service staff creates audit plan with the customer that contains information about: scope/needs for NOTATION PROCESS Activity ARTEFACT PHASE TOOL CONNECTOR CREATE / STORE USE / RETRIEVE AUTHOR CONTRIBUTOR COMPOSITE ARTEFACT Maintenance Implementation & Follow-up Audit Service staff Audit service Service manager Customer Service staff 1 Plan audit Audit plan 3 Field Research Service staff Service manager Customer R&D Optional Service staff 2 Office Research Instrumented data 4 data analysis, report Data Installed Report Audit checklist Data server Engineering & Maintenance Lifecycle Services Information Management & Web Reports 0- mV 100 10deg 50 Network Architecture 100 Mbit/s Switched Ethernet PCS PCS BU/ AL P Audit report Sales leads Actions based on agreement between customer and vendor Action plan & roadmap Re-evaluate audit needs or start periodic audit Installation information ”Tell me your configuration” ”Instrumented data” Office Network Router 100 Mbit/s 5 Presentation / Communicate / Negotiate Service manager Customer Service staff Service staff Customer Customer extranet Installed Base Operator Interface Service manager Sales Manager Service staff Customer 1,2 Interfaces to: Installation information - PLC - DCS - QCS Distributed I/O’s Centralized I/O’s HART Target system Plug-ins, sensors Fig. 2 Description of the Audit Process. 55 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Field research –activity (optional): The purpose of Field Research is to acquire supplementary information/data during site visits. This activity is optional if Office research–activity is not sufficient. In this activity, Service staff carries out field research tasks according to product-specific checklists (check instruments, get info about maintenance, training needs, remarks concerning configuration, visual check, check the function of the product, corrosion, etc.). Furthermore, staff collects additional installation information from the customer premises (customer-specific product installation), if needed. practice the needs of the Service organization could be taken into account during product development. What kind of service/R&D collaboration could improve the quality and lead time of the industrial services? Target is not to describe service development process but try to understand and collect industrial best practices that increase service/R&D collaboration and transparency so that customers can be better and faster serviced. Naturally these practices are highly service dependent since each service need different issues from R&D organization. During the interviews, it become obvious that already on product platform Business Planning phase there has to be analysis activity how new proposed features of the system will be supported by services and what kind of effects there are for different services (e.g. compatibility). Therefore, already in system business planning phase one should consider technical support, product/technology lifecycle and version compatibility issues from service viewpoint before the implementation starts. Data analysis/report –activity: Purpose of Data analysis/Report is to analyze collected data and prepare a report that can be communicated with the customer. Data analysis –task analyses audit data and observations. Service staff utilize audit checklist and consult R&D in analysis, if needed. Depending upon the audit, the analysis may contain e.g.: maintenance, part or product obsolence, replacements, inventory, needs for training, etc. During the analysis customer should prepare time and contacts to answer questions that may arise concerning audit data. Service staff and manager defined recommendations based upon the audit. The Service Manager identifies sales leads related to the audit results. In addition, staff will update installation information into InstalledBase if discrepancies have been observed. The audit report will contain an introduction, definition of scope, results, along with conclusions and recommendations. The report will be reviewed internally and stored into the Customer Extranet and the Customer will be informed (well in advance, in order to allow time for customer to check the report). Based on cases above the following service/R&D collaboration practices were identified. Basically both cases highlight communication and information transparency between the organizational units. 5.1 Case 1: collaboration related to Upgrade –service In case 1 there was a nominated person who works in service/R&D interface, i.e. Product Manager who works in Service interface (Fig. 3). This person defines and updates life-cycle rules document that contains information e.g.: - Presentation/communicate/negotiations–activity: This activity presents results to the key stakeholders and agrees future actions/roadmaps. The Service Manager agrees with the customer the time and participants of result presentation event. The results will be presented and discussed. The Service Manager negotiates about the recommendations and defines actions/roadmaps based on recommendations (first step towards price and content negotiations). - - 5. Case analysis how long each technology will be supported. In other words, e.g. how long the particular version of each operating system (OS) will be supported (product & service/security packs), along with considerations of if there is any possibility of extended support). hardware – software compatibility (e.g. OS version vs. individual workstations) compatibility information showing how different sub-systems are compatible with each other (compatible, compatibility restrictions, not compatible). other rules or checklists containing what needs to be considered when conducting upgrades (conversions of file formats, etc.) Integrated service/product development has been studied a lot. However, there is less information available how in 56 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Life cycle policy Parallel: Product manager that works in Service interface Product manager(s) Product manager Optional: Collect COTS LC info Lifecycle info (enable Upgrade Planning) 3rd party tech LC info Installed Base Define and update life cycle rules Product manager Collect sub-system lifecycle info Internal tech LC info Product manager Technology life cycle information Collect sub-system compatibility info Life cycle rules Upgrade planning -process Internal compatibility info Fig. 3 Collect lifecycle rules -process. 1. The rules are used by the Service function in order to understand the lifecycle effects to the system. For instance, in Upgrade Planning -process in upgrade analysis -activity this information is used to compose life cycle plans for customers. Product manager that works in Service interface coordinates the composition of lifecycle rules. These rules originate from internal and external sources. External information is collected from third-party system providers (COTS providers). This information comes, for instance, from operating system providers (a roadmap that shows how long operating system versions will be supported). Internal lifecycle information originates from R&D (product creation and technology research functions). Internal lifecycle information defines in-house developed automation system components and their support policy. Furthermore, lifecycle information about system dependencies is also important (compatibility information). Dependency information shows the dependencies between sub-systems and components so as to detect how changes in one sub-system may escalate to other sub-systems in a customer’s configuration. Finally, rules are also affected by a company’s overall lifecycle policy (i.e. the policy on how long (and how) the company decides to support the systems). Some of these rules are implemented into the InstalledBase tool that partly automates the generation of lifecycle plan. However, since every customer tends to be unique some rules need to be applied manually depending on the upgrade needs. 2. 3. 4. 5. Based on this case we could compose a task list for the Product Manager who works in the service interface. Product manager’s task is to increase and facilitate communication between the R&D and Service organizations (collaboration between organizational units): Coordinates the collection, maintenance and documentation of lifecycle rules in cooperation with R&D to support upgrade planning. Communicates to R&D how they should prepare for lifecycle issues (how R&D should take into account service needs?). Defines the lifecycle policy with company management. Coordinates that Service Managers are creating lifecycle plans for their customers. The objective is that there are as many lifecycle plans as possible (every customer is a business possibility). Participates to the lifecycle support decision making together with R&D (e.g. replacement/spare part decisions, compatibility between platform releases). For instance: - decisions concerning how long the company provides support for different technologies/components. Decisions what technologies will be used (smaller changes/more significant changes). Service organization will make the decision (cooperation with R&D). - decisions about the compatibility. Service provides needs/requirements for compatibility (based on effects to service business). R&D tells what is possible => needs and possibilities are combined so that optimal compatibility is possible for upgrade business (service organization makes the decision). - determines the volume/quantity components there are in field (check from InstalledBase) => effects to the content of next platform release and what support are needed from service viewpoint. 57 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org 5.2 Case 2: Collaboration related to Audit –service organizations. The approach has some similarities to the solution that is presented in [10]. Similarly their case study indicated that there were need to have units that worked in between the organizations that enabled the interaction. In case 2, the Service staff utilizes audit checklists that have been prepared collaboratively by Service and R&D, and consults R&D in the audit analysis, if required. The training team that works in the Service organization is responsible for the coordination of the collection and maintenance of the audit checklists (Fig. 4). The checklists are to be composed and maintained in cooperation with R&D. Checklists are product-specific since different issues need to be checked depending on product type. Furthermore, checklists require constant updates as the product platforms evolve, e.g. one needs to check different issues from products of different age. Training team (service) R&D Key service staff persons Audit info (enable Audit service) Based on this research, it is possible to better understand interfaces and needs between Service and R&D organizations. With this information it is possible to begin to improve the collaboration practices and solutions in case company. This research provides for other companies and research institutes that work with industrial companies the practical real-life cases how Service and R&D organizations collaborate. This research is based on bottom-up approach studying two cases and therefore the results are limited since the collaboration is service dependent. This study does not try to explain why the case company has ended up with these practices and solutions, nor that these practices are directly applicable to other companies. However, we described the case in fairly detailed context in section 3 and Service processes in section 4. Therefore, this article provides for industrial companies a good ground to compare their operational environment with the one presented in this article and apply the collaboration practices when appropriate and applicable. For us, this study creates a basis for further research to study the collaboration needs of the other industrial services – for instance such as preventive maintenance services, optimization services, security assessment services. Audit -process Compose audit checklists Audit checklist Fig. 4 Compose audit checklist -process. 6. Discussion and conclusions The importance of industrial services has increased and there needs to be systematic practices/processes to support service and product development. This has been indicated also in other studies, e.g. in [1, 2]. However, there is less information available concerning how in practice the needs of the Service organization could be taken into account during product development. What kind of service/R&D collaboration could improve the quality and lead time of the industrial services? In this article, objective is not to describe service development process but rather to try to understand and collect industrial best practices that increase the collaboration and transparency between service and R&D organizations so that customers can be better and faster serviced. Acknowledgments This research has been done in ITEA2 project named Promes [13] and Artemis project named Varies [12]. This research is funded by Tekes, Artemis joint undertaking, Valmet Automation and VTT. The authors would like to thank all contributors for their assistance and cooperation. References [1] A. Tukker, U. Tischner. “Product-services as a research field: past, present and future. Reflections from a decade of research”, Journal of Cleaner Production, 14, 2006, Elsevier, pp. 1552-1556. [2] J.C. Aurich, C. Fuchs, M.F. DeVries. “An Approach to Life Cycle Oriented Technical Service Design”, CIRP Annals Manufacturing Technology, Volume 53, Issue 1, 2005, pp. 151–154. [3] H.W. Borchers, H. Karandikar. “A Data Warehouse approach for Estimating and Characterizing the Installed Base of Industrial Products”. International conference on Service systems and service management, IEEE, Vol. 1, 2006, pp. 53-59. [4] R. Oliva, R. Kallenberg. “Managing the transition from products to services”. International Journal of Service Industry Management, Vol. 14, No. 2, 2003, pp. 160-172 This article aims to discuss the collaboration and transparency of Service and R&D organizations using two cases that give practical examples about the collaboration, i.e. what the collaboration and transparency between Service and R&D organizations means in real-life industrial environment. Furthermore, the article reports what kind of solutions the case company uses to realize the collaboration. The article shows that in case company service needs were taken into account already in business planning phase of the product development process. Furthermore, there were roles and teams that worked between service and R&D organizations to facilitate the interaction between the 58 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Dr. Antti Välimäki works as a senior project manager in Valmet Automation as a subcontractor. He has worked in many positions from designer to development manager in R&D and Service in Valmet/Metso Automation. He has received a Ph.D. degree in 2011 in the field of Computer Science. He has over 20 years of experience with quality management and automation systems in industrial and research projects. [5] ICT for Manufacturing, The ActionPlanT Roadmap for Manufacturing 2.0. [6] K. Sundaram. “Industrial Services- A New Frontier for Business Model Innovation and Profitability”, Frost and Sullivan, https://www.frost.com/sublib/display-marketinsight.do?id=287324039 (accessed 24th June 2015). [7] M.A. Cusumano. “The Chaning Software Business: Moving from Products to Services”. Published by the IEEE Computer Society, January, 0018-9162/08, 2008, pp. 20 – 27. [8] J. Hanski, S. Kunttu, M. Räikkönen, M. Reunanen. Development of knowledge-intensive product-service systems. Outcomes from the MaintenanceKIBS project. VTT, Espoo. VTT Technology : 21, 2012. [9] M. Bano, D. Zowghi. “User involvement in software development and system success: a systematic literature review”. Proceedings of the 17th International Conference on Evaluation and Assessment in Software Engineering, 2003, pp. 125-130. [10] N. Lakemond, T. Magnusson. “Creating value through integrated product-service solutions: Integrating service and product development”, Proceedings of the 21st IMPconference, Rotterdam, Netherlands, 2005. [11] L. Poulsen. “Life-cycle and long-term migration planning”. InTech magazine (a publication of the international society of automation), January/February 2014, pp. 12-17. [12] Varies -project web-site: (Variability In Safety-Critical Embedded Systems) http://www.varies.eu/ (accessed 24th June 2015). [13] Promes -project web-site: (Process Models for Engineering of Embedded Systems) https://itea3.org/project/promes.html (accessed 24th June 2015). [14] S. Charalampidou, A. Ampatzoglou, P. Avgeriou. “A process framework for embedded systems engineering”. Euromicro Conference series on Software Engineering and Advanced Applications (SEAA'14), IEEE Computer Society, 27-29 August 2014, Verona, Italy. [15] J. Kääriäinen, S. Teppola, M. Vierimaa, A. Välimäki. ”The Upgrade Planning Process in a Global Operational Environment”, On the Move to Meaningful Internet Systems: OTM 2014 Workshops, Springer Berlin Heidelberg, Lecture Notes in Computer Science (LNCS), Volume 8842, 2014, pp 389-398. Dr. Jukka Kääriäinen works as a senior scientist in VTT Technical Research Centre of Finland in Digital systems and services -research area. He has received a Ph.D. degree in 2011 in the field of Computer Science. He has over 15 years of experience with software configuration management and lifecycle management in industrial and research projects. He has worked as a work package manager and project manager in various European and national research projects. Mrs. Susanna Teppola (M.Sc.) has worked as a Research Scientist at VTT Technical Research Centre of Finland since 2000. Susanna has over fifteen years’ experience in ICT, her current research interests are laying in the area of continuous software engineering, software product/service management and variability. In these areas Susanna has conducted and participated in many industrial and industry-driven research projects and project preparations both at national and international level. 59 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Load Balancing in Wireless Mesh Network: a Survey Maryam Asgari1, Mohammad Shahverdy2, Mahmood Fathy3, Zeinab Movahedi4 1 Department of Computer Engineering, Islamic Azad University-Prof. Hessabi Branch, Tafresh, Iran [email protected] 2 Department of Computer Engineering, Islamic Azad University- Prof. Hessabi Branch,Tafresh and PHD student of University of Science and Technology, Tehran Iran [email protected] 3, 4 Computer Engineering Faculty, University of Science and Technology Tehran,Iran [email protected],[email protected] Abstract wireless network has only a single hop of the path and the Clients need to be within a single hop to make connectivity with wireless access point. Therefore to set up such networks need access points and suitable backbone. As result a Deployment of large-scale WLANs are too much cost and time consuming. However, The WMNs can provide wireless network coverage of large areas without depending on a wired backbone or dedicated access points [1, 2]. WMNs are the next generation of the wireless networks that to provide best services without any infrastructure. WMNs can diminish the limitations and to improve the performance of modern wireless networks such as ad hoc networks, wireless metropolitan area networks (WMANs), and vehicular ad hoc networks [2,3,4 and 5]. WMNs are multi-hop wireless network which provide internet everywhere to a large number of users. The WMNs are dynamically self-configured and all the nodes in the network are automatically established and maintain mesh connectivity among themselves in an ad hoc style. These networks are typically implemented at the network layer through the use of ad hoc routing protocols when routing path is changed. This character brings many advantages to WMNs such as low cost, easy network maintenance, more reliable service coverage. Wireless mesh network has different members such as access points, desktops with wireless network interface cards (NICs), laptops, Pocket PCs, cell phones, etc. These members can be connected to each other via multiple hops. In the full mesh topology this feature brings many advantages to WMNs such as low cost, easy network maintenance and more reliable service coverage. In the mesh topology, one or multiple mesh routerscan be connected to the Internet. These routers can serve as GWs and provide Internet connectivity for the entire mesh network. One of the most important challenges in these networks happens on GW, when number of nodes which connected to the internet via GW, suddenly increased. It means that GWs will be a bottleneck of network and Wireless Mesh network (WMN) is a state of the art networking standard for next generation of wireless network. The construction of these networks is basis of a network of wireless routers witch forwarding each other’s packets in a multi-hop manner. All users in the network can access the internet via Gateways nodes. Because of the high traffic load towards gateway node, it will become congested. A load balancing mechanism is required to balance the traffic among the gateways and prevent the overloading of any gateway. In this paper, weinvestigatedifferent load balancing techniques in wireless mesh networks to avoid congestion in gateways,as well as we survey the effective parameters that is used in these techniques. Keywords:clustering, Gateway, Load Balancing, Wireless Mesh Network (WMN). 1.Introduction Wireless mesh networking is a new paradigm for next generation wireless networks. Wireless mesh networks (WMNs) consist of mesh clients and mesh routers, where the mesh routers form a wireless infrastructure/backbone and interwork with the wired networks to provide multi hop wireless Internet connectivity to the mesh clients. Wireless mesh networking has generated as a selforganizing and auto-configurable wireless networking to supply adaptive and flexible wireless Internet connectivity to mobile users. This idea can be used for different wireless access technologies such as IEEE 802.11, 802.15, 802.16-based wireless local area network (WLAN), wireless personal area network (WPAN), and wireless metropolitan area network (WMAN) technologies. WMNs Potential application can be used in home networks, enterprise networks, community networks, and intelligent transport system networks such as vehicular ad-hoc networks. Wireless local area networks (WLANs) are used to serve mobile clients access to the fixed network within broadband network connectivity with the network coverage [1]. The clients in WLAN use of wireless access points that are interconnected by a wired backbone network to connect to the external networks. Thus, the 60 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org performance of the network strongly decreases [4, 5, and 6]. A mesh router hearing the route request uses the information in the RREQ to establish a route back to the RREQ generator. 2.Related Work The problem of bottleneck in wireless mesh networks is an ongoing research problem although much of the literature [7, 8, 9, 10] available, addresses the problem without an introducing method for removing bottleneck and/or a welldefined way to prevent congestion. In [11], the authors proposed the Mesh Cache system for exploiting the locality in client request patterns in a wireless mesh network .The Mesh Cache system alleviates the congestion bottleneck that commonly exists at the GW node in WMNs while providing better client throughput by enabling content downloads from closer high throughput mesh routers. There is some papers related to optimization problems on dynamic and static load balancing across meshes [11].Optimal load balancing across meshes is known to be a hard problem. Akyildiz et al.[12] exhaustively survey the research issues associated with wireless mesh networks and discusses the requirement to explore multipath routing for load balancing in these networks. However, maximum throughput scheduling and load balancing in wireless mesh networks is an unexplored problem. In this paper we survey different load balancing schemes in wireless mesh networks and briefly introduce some parameters witch they used in their approaches. Fig.1 Broadcasting RREQs[13] During the path selection phase a source should decide which path is the best one among the multiple pathsfigured out in the first phase. The path selection can be prioritized in following order: (a)If there exist multiple paths to a source’s primary gateway then, take the path with minimum hop count and if there is still a tie, we can randomlyopt a path. (b)If there is no path to source’s primary gateway but a several paths to secondary gateways then take the path with minimum hop count and if there is still a tie opt a path randomly. 3.Load Balancing Techniques Increasing Load in a wireless mesh network causes Congestion and it is lead to different problems like packet drop, high end to end delay, throughput decline etc. various techniques have been suggested that considers load balancing are discussed below. As it’s clear, congestion control is based on bandwidth estimation technique,thereforeavailable bandwidth on a link should be identified.Here the consumed bandwidth information can be piggy packed on to the “Hello” message which is used to maintain local connectivity among nodes. Each host in the network determines its devoted bandwidth by monitoring the packets it sends on to the network. The mesh router can detect the congestion risk happening on its each link by the bandwidth estimation technics. A link is in risk of congestion whenever the available bandwidth of that link is less than a threshold value of bandwidth. If a link cannot handle more traffic, it will not accept more requestsover that link. The primary benefit of this protocol is that it simplifies routing algorithm but it needs preciseknowledge about the bandwidth of each link. 3.1 Hop-Count Based Congestion-Aware routing [13] In this routing protocol, each mesh router rapidly finds out multiple paths based upon hop count metric to the Internet gateways by routing protocol designing. Each mesh routerequipped to a bandwidth estimation technique to allow it to forecast congestion risk, then router select high available bandwidth link for forwarding packets. Multipath routing protocol consists two phases: Route discovery phase and path selection phase. In the route discovery phase, whenever a mesh router tries to find a route to an internet gateway, it initiates a route discovery process by sending a route request (RREQ) to all its neighbors. The generator of the RREQ marks the packet withits sequence number to avoid transmitting the duplicate RREQ. 3.2 Distributed Load Balancing Protocol. [14] In this protocol the gateways coordinates to reroute flows from congested gateways to other underutilized gateways. This technique also considers interference which can be appropriate for practical scenarios, achieving good results 61 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org and improving on shortest path routing. Here the mesh network is divided into domains. A domain di can be defined as set of routers witch receive internet traffic and a gateway witch serve them. For each domain a specific capacity is assigned and is compared against the load in the domain. The domain is considered as overloaded if the load exceeds the sustainable capacity. To avoid congestion in a domain we can reroute the traffic. This technique does not impose any routing overhead in the network. 3.4 DGWLBA: Distributed Gateway Load balancing Algorithm [16] In [16] gateways execute DGWLBA to attain load balancing. DGWLBA starts by assigning all routers to their nearest gateway that is called theNGW solution. Next steps consist in trying to reroute flows from an overloaded domain d1 to an uncongested domain d2 such that the overload of both domains is reduced. Fig.2 Mesh network divided into domains for loadbalancing [14] Fig.3 WMNs divided into 3 domains each having capacity 25[16] 3.3 Gateway–Aware Routing [15] If domain is overloaded, its sinks are checked in descending order of distance to their serving gateway. This is done to givepreferenceto border sinks. The farther a sink is fromits serving gateway the less it will harm other flows of its domain if it is rerouted. And its path to other domains will be shorter, thus improving performance. For the same reason, when a sink is chosen, domains are checked in ascendingorder of distance to the sink. Next, to perform the switching of domains, the overload after the switch must be less than the overload before the switch (lines 9-11). Lastly, the cost of switching is checked. nGWsis the gateway nearest toΔs . Only if the cost is less than the switching threshold Δsit will be performed (line 12). This rule takes into account the existence of contention, because it prevents the establishment of long paths, which suffer from intra-flow interference and increase inter-flow interference in the network, and gives preference to border sinks. Hence this approach successfully balances load in overloaded domains considering congestion and interference. In [15] a gateway mesh aware routing solution is proposed that selects gateways for each mesh router based on multihop route in the mesh as well as the potentiality of the gateway. A composite routing metric is designed that picks high throughput routes in the presence of multiple gateways. The metric designed is able to identify congested part of each path, and selectasuitable gateway. The gateway capacity metric can be defined as the time needed to transmit a packet of size S on the uplink and is expressed by gwETT=ETXgwS/Bgw (1) Where ETXgw is the expected transmission count for the uplink and Bgw is the capacity of the gateway. For forwarding packets a GARM(Gateway Aware Routing Metric) is defined which is follows: GARM =β.Mi + (1-β) .(mETT+gwETT) (2) This Gateway-aware Routing Metric has two parts.The first part of the metric is for bottleneck capacity and the second part accounts the delay of the path. The β is used forbalancing between these two factors. The gateway with minimum GARM value can be chosen as the default gateway for balancing the load. This scheme overcomes the disadvantage of accurate bandwidth estimation suggested in [6] and also improves network throughput. ALGORITHM for each gateway GWi do di={ }; for each sink s do if ( distance(s,GWi) = minimum) Add sink s to di; For domain d1 in D do if load(d1) > Cd1 then For sink s in d1 do 62 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org For domain d2 in D do If d1=d2 then Continue Ovldbefore = ovld(d1) + ovld(d2) Ovldafter = ovld(d1-{s}) + ovld(d2 U {s}) If ovldafter< ovldbefore then If dist(s,GW2) / (dist(s,nGWn) < ∆s then d1 = d1 – {s} d2 = d2 U {s} break; If load(d1) ≤ Cd then Break; node that has larger G_Value is more suitable for being a GW. Fig.4 Breaking a cluster[17] 3.5 Load Balancing in WMNs by Clustering[17] Althoughthe paper considers most of the design aspects of the proposed infrastructure, it leavessome open issues and questions. For instance, surveying load balancing of multichannel GWs in clustering wireless mesh networks, finding maximum throughput of nodes incluster based wireless mesh networks. Another open issue is using fuzzy logic for breaking the clusters. In [17] authors proposed a load balancing schemes for WMNs by clustering. In first step all nodes are clustered to control the workload of them. If workload on a GW is increased up tomaximum capacity of the GW then the cluster is broken. With the respect to the gateways capacity, the gateways overload can be predictable. Because selecting a new GW andestablish a route table is time consuming, thus third scheme is proposed which GWselection and creating route table is done before breaking the cluster. Also they considered some parameters for selecting the new GW in new cluster witch isoffered in following formula: = × × × 4. Conclusion Load balancing is one of the most important problems in wireless mesh networks that needs to be addressed. The nodes in a wireless mesh network trend to communicate with gateways to access the internet thus gateways have the potential to be a bottleneck point. Load balancing is essential to utilize the entire available paths to the destination and prevent overloading the gateway nodes. In this paper we surveyed different load balancing scheme with various routing metrics that can be employed to tackle load overhead in the network. Table1 summarizes the load balancing techniques witch we surveyed in this paper. (3) Where Power is the power of a node, Power is the processing power of each node, Constancy is the time which a node actively exists in cluster, Velocity is the spped of each node and Distance is the distance of the node to centeral of the cluster. In the above formula, they calculate G_Value for each node in a cluster and then each Table1: Summery of different techniques Technique Metric Advantages Issues that not Addressed Hop Count based Congestion Aware routing. Hop Count No routing overhead. Computational overhead. accurate bandwidth information required. Distributed Load Balancing Protocol Hop Count No Routing overhead. Computational Overhead. GARM No routing overhead, High throughput. Computational Overhead. Queue Length Low end to end delay Routing and Computational Overhead. Queue Length Low end to end delay Cluster initial formation parameter Gateway-Aware Routing DISTRIBUTD GATEWAY LOADBALANCING Load Balancing in WMNs by Clustering 63 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org The Nominal Capacity of Wireless Mesh Networks, IEEE Wireless Communications, vol. 10, no 5,pp. 8– 14. [10] Abu, R., Vishwanath R., Dipak G., John B., Wei L., Sudhir D., Biswanath M., (2008). Enhancing Multi-hop Wireless Mesh Networks with a Ring Overlay, SECON workshop. [11] Horton, G. (1993). A multi-level diffusion method for dynamic load balancing, Parallel Computing. 19 pp. 209-229. [12] Akyildiz, I., Wang, X., Wang, W.,(2005). Wireless Mesh Networks: A Survey, Computer Networks Journal 47, (Elsevier), pp. 445-487. [13] Hung Quoc, V.,Choong Seon, H., (2008). Hop-Count Based Congestion-Aware Multi-path Routing in Wireless Mesh Network, International Conference on Information Networking, pp. 1-5 . [14] Gálvez, J.J., Ruiz, P.M., Skarmeta, A.F.G, (2008). A Distributed Algorithm for Gateway Load-Balancing in Wireless Mesh Networks, Wireless Days. WD '08. 1st IFIP, pp. 1-5. [15] Prashanth A. K., David L, Elizabeth M.,(2010). Gateway–aware Routing for Wireless Mesh Networks, IEEE International Workshop on Enabling Technologies and Standards for Wireless Mesh Networking (MeshTech), San Francisco. [16] GUPTA, B. K., PATNAIK, S., YANG, Y.,(2013). GATEWAY LOAD BALANCING IN WIRELESS MESH NETWORKS, International Conference on Information System Security And Cognitive Science, Singapore. [17] Shahverdy, M., Behnami, M., Fathy, M.,(2011). A New Paradigm for Load Balancing in WMNs, International Journal of Computer Networks (IJCN), Volume (3), Issue (4). References [1] Bicket, J., Aguayo, D., Biswas, S., Morris, R.,(2005). Architecture and evaluation of an unplanned 802.11b mesh network, in: Proceedings of the 11th ACM Annual International Conference on Mobile Computing and Networking (MobiCom), ACM Press, Cologne, Germany, pp. 31–42. [2] Aoun, B., Boutaba, R., Iraqi, Y., Kenward, G. (2006 ). Gateway Placement Optimization in Wireless Mesh Networks with QoS Constraints. IEEE Journal on Selected Areas in Communications, vol. 24. [3] Hasan, A.K., Zaidan, A. A., Majeed, A., Zaidan, B. B, Salleh, R., Zakaria, O., Zuheir, A. (2009). Enhancement Throughput of Unplanned Wireless Mesh Networks Deployment Using Partitioning Hierarchical Cluster (PHC), World Academy of Science, Engineering and Technology 54. [4] Akyildiz, I.F., Wang, X., Wang, W.,(2005). Wireless mesh networks: a survey, Elsevier ,Computer Networks 47, 445–487. [5] Jain, K., Padhye, J., Padmanabhan, V. N., Qiu, L.,(2003). Impact of interference on multihop wireless network performance, in Proceeding of ACM MobiCom, 66-80. [6] Akyildiz, I., Wang, X., (2005). A survey on wireless mesh networks, IEEE Communication Magazine, vol. 43, no.9, pp.s23-s30. [7] MANOJ, B.S., RAMESH, R.,(2006). ,WIRELESS MESH NETWORKING, Chapter 8 ,Load Balancing in Wireless Mesh Networks, page 263. [8] Saumitra Das, M., Himabindu Pucha , Charlie Hu,Y.,(2006). Mitigating the Gateway Bottleneck via Transparent Cooperative Caching in Wireless Mesh Networks, NSF grants CNS-0338856 and CNS-0626703. [9] Jangeun, J., Mihail, L.,(2003). 64 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Mobile Banking Supervising System- Issues, Challenges & Suggestions to improve Mobile Banking Services Dr.K.Kavitha Assistant Professor, Department of Computer Science, Mother Teresa Women’s University, Kodaikanal [email protected] Abstract Table 1 - Technology Usage Survey Banking is one of the Largest Financial Institution which constantly provides better Customer Services. To improve the Service Quality, Banking Services are expanded to Mobile Technology. Recently Mobile Banking plays a vital role in Banking Sector. This technology helps the Customers to provide all the account information as well as save timings. Customer can avail all financial services such as Credit, Debit, Money Transfer, Bill Payment etc in their Mobiles using this application. It saves time to speed in a Bank. Almost, most of the banks providing financial services through Mobile phones. But still majority of peoples are not preferred this services like ATM or Online because of Risk Factor. The main objective of this paper is to discuss about the benefits, issues and suggestions to improve Mobile Banking services successfully. 25 Online Banking 20 Mobile Banking 5 30 40 75 Issues ATM Preferable Risk Factor Keywords: ATM, Online Service, Mobile Banking, Risk Rating, MPIN, Log Off 1. Introduction Mobile Banking System allows the Customers to avail all financial services through Phones or Tablets. The traditional Mobile Banking Services offered through SMS which is called as SMS Banking. Whenever the Customer availed Transaction either Debit or Credit, SMS will be sent to the Customers accordingly. But this service offer two transactions only such as Credit and Debit. Other benefits are gathered by spending money for SMS. New technology is rapidly modified the traditional Systems of doing banking services. Banking Services is expanded up to this technology. By using iphones, Customers can download and use Mobile applications for further financial Services. This service avoids the Customers going to branch premises and provided more Services. The Usages of technological Financial Services was tested by 50 Customers and most of them indicated that major risk service is Mobile Banking instead of ATM and Online Services as follows in table 1 Figure 1 - Technology Usage Survey Chart The above table and figure proves that the major risk comes under the third category such as Mobile Banking. ATM and Online Services are having minimum Risks comparable with mobile banking services. So that, in this Survey indicates that mostly preferred service is ATM then the next option is Online Services. This paper studies the benefits, limitations and suggestions to improve the mobile banking services. 2. Related Work Renju Chandran [1] suggested some ideas and presented three steps to run and improve the mobile banking services effectively. The author presented the benefits, limitations and problems faced by the customer during the transaction of mobile banking and suggested a method for improving that service. Aditya Kumar Tiwari.et.al [2] discussed about mobile banking advantages, drawbacks, Security issues and challenges in mobile banking services and proposed 65 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org some idea to get the solution of mobile banking security. V.Devadevan [3] conversed about Mobile Compatibility, Mindset about Mobile Banking acceptance and Security issues. The author depicted from the study that the evolution of eminent technologies in communication system and mobile device is a major factor and challenge to frequently changing the mobile banking solutions. The author suggested creating awareness among the existing customers and providing special benefits for mobile bankers which will increase the service. MD. Tukhrejul Inam.et.al[4] described the present condition of mobile banking services in Bangladesh and also showed prospects and limitations of Mobile banking in their country. The author suggested to the Bangladesh banks to follow the mobile banking services for making their lives easier.Mobile phones target the world's nonreading poor[5] disussed the Modern Cell Phone usage and functionalities. ii. iii. iv. v. Internet Connection is necessary to avail these Services. If the Customers reside in rural area means then they cannot avail the services because of Tower problem or line breakage. AntiVirus Software Updation Many Customers are not aware about Anti Virus Software so that spyware will affect their mobiles. Forget to Log Off if Customer’s mobile phone theft means unauthorised person can reveal all our transaction details. Mobile Compatibility Latest Mobile Phones alone suited for availing these services Spend Nominal Charge For Regular Usage, Customers has to spend some nominal Charges for transactions 3.2 Identify the Major Issue in Mobile Banking 3. Objectives of Mobile Banking System Customers mostly prefer ATM and Online Services. Mobile Banking is not preferred by many because of the above limitations. Customers have to aware about Mobile Banking Services before usage. The awareness and Risk about Mobile Banking was tested by 50 Customers and Comparable with other risk factor most pointed out the “forget to Log off” Issue in these Limitations as follows. The following steps are discussed in the next Section 1. Benefits & Limitation of Mobile Banking 2. Identify the Major Issue in Mobile Banking 3. Suggestion proposed to improve the Mobile Banking Services. 3.1 Benefits & Limitations of Mobile Banking Table 2 - Risk Ratings in Mobile Banking Issues in Mobile Banking Benefits of Mobile Banking i. Reduce Timing Instead of going to bank premises and waiting in a Queue for checking the account transactions, Customers can check all details through Mobile Phones ii. Mini Statement In Offline Mode, We can see our Transaction Details through Mini Statement by using MPIN iii. Security During Transactions like Amount Transfer, SMS Verification Code is provided for checking the Authorised Persons. iv. Availability At any time, Customers can avail all the Services through Mobile Phones v. Ease of Use User Friendly. Customers can access all the financial services with little knowledge about mobile application. Compulsory Internet Connection & Tower Problem Risk Ratings 5 4 3 2 1 25 5 5 10 5 10 20 20 10 40 Anti Virus Software Updation Forget to Log Off & Misuse Mobile Phones 35 5 10 Mobile Compatibility Spend Nominal Charge 10 Limitations of Mobile Banking i. Compulsory Internet Connection & Tower Problem 66 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. 40 ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org invoked by MBMS. Clock Time Limits are not fixed, Customers can change the limits at any time. Mobile Banking Log in Process Transactio n Process Monitor all Transaction s Figure 2 - Risk Ratings in Mobile Banking Chart Mobile Banking Supervising System The above collected data also indicates that 70% of Customers mentioned the “Forget to Log Off & Misuse of Mobile Phones due to theft” is a major risk factor in the above list. The author suggested an idea to improvise the mobile banking services in the next section 3.3 Suggestion proposed to improve the Mobile Banking Services Log Out Process / Skip Skip returns or time expires Invoke Log Off Service Figure 3 - MBSS Model Design 5. Conclusion In Mobile Banking Applications, whenever we need to avail financial services we have to enter our User name and Password for using our account transactions. After completion of our task, Customers have to log off these services. But sometimes, for regular usage Customers may forget or postponed to log off. At that time, This mobile application always keep inside the corresponding Customer’s Account Database. If the Customers mobile phones theft means, automatically hackers can reveal all their transaction details very easily. This will become a very big issue. Banking Sector has to avoid this type of problems by using new emerging technologies. At the Same time, Customers also have to aware about these Services like How to use these apps, what are the security measures taken by the banking sector and how to avoid major risks from unauthorized persons. Mobile Banking is a convenient financial services to the Customers. Customers can avail all account transactions like Bill payment, Credit Amount, Debit Amount, Fund Transfer etc. It offers many benefits with ease of use. But still it has some limitations. So this paper discussed the major issues faced by the Customer & Banks Sector through Mobile Banking services and suggested an idea for protecting the account information from unauthorised persons through Mobile Banking Supervising System. References [1] Renju Chandran “Pros and Cons of Mobile Banking”International Journal of Scientific Research Publications, Volume 4 Issue 10 October 2014.ISSN 2250-3153 [2] Aditya Kumar Tiwari, Ratish Agarwal, Sachin Goyal “Imperative & Challenges of Mobile Banking in India”International Journal of Computer Science & Engineering Technology, Volume 5 Issue 3 March 2014. ISSn 2229-3345 [3] V.Devadevan “ Mobile Banking in India- Issues & Challenges” – International Journal of Engineering Technology and Advanced Engineering, Volume 3, Issue 6, June 2013. ISSN 2250-2459 [4] MD.Tukhrejul Inam, MD.Baharul Islam “ Possibilities and Challenges of Mobile Banking: A Case Study in Bangladesh” International Journal of Advanced Computational Engineering and Networking, Volume 1 Issue 3 May 2013, ISSN: 2321-2106. [5] L.S.Dialing, “Mobile Phones target the world’s non reading poor”, Scientific American, Volume 296 issue 5 2007. 4. Proposed Mobile Banking Supervising System [MBSS] This paper suggested to implement Mobile Banking Supervising System [MBSS] along with mobile banking applications for protecting and keep track all the sensitive information. For tracking all the transactions, MBMS keeps Stop Watch for monitoring the Services regularly like Log in Timing, transaction Particulars, Log off (or) skip the application. Everything has to be monitored by MBSS. If the Customer skips these mobile apps or forgets to log off keep on staying means, Automatic Log off Functions is 67 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org A Survey on Security Issues in Big Data and NoSQL Ebrahim Sahafizadeh1, Mohammad Ali Nematbakhsh2 1 Computer engineering department, University of Isfahan Isfahan,81746-73441,Iran [email protected] 2 Computer engineering department, University of Isfahan Isfahan,81746-73441,Iran [email protected] Abstract 2.1 Big Data This paper presents a survey on security and privacy issues in big data and NoSQL. Due to the high volume, velocity and variety of big data, security and privacy issues are different in such streaming data infrastructures with diverse data format. Therefore, traditional security models have difficulties in dealing with such large scale data. In this paper we present some security issues in big data and highlight the security and privacy challenges in big data infrastructures and NoSQL databases. Keywords: Big Data, NoSQL, Security, Access Control Big data is a term refers to the collection of large data sets which are described by what is often referred as multi 'V'. In [8] 7 characteristics are used to describe big data: Volume, variety, volume, value, veracity, volatility and complexity, however in [9], it doesn't point to volatility and complexity. Here we describe each property. Volume: Volume is referred to the size of data. The size of data in big data is very large and is usually in terabytes and petabytes scale. Velocity: Velocity referred to the speed of data producing and processing. In big data the rate of data producing and processing is very high. Variety: Variety refers to the different types of data in big data. Big data includes structured, unstructured and semistructured data and the data can be in different forms. Veracity: Veracity refers to the trust of data. Value: Value refers to the worth drives from big data. Volatility: "Volatility refers to how long the data is going to be valid and how long it should be stored" [8]. Complexity: "A complex dynamic relationship often exists in big data. The change of one data might result in the change of more than one set of data triggering a rippling effect" [8]. Some researchers defined the important characteristics of big data are volume, velocity and variety. In general, the characteristics of big data are expressed as three Vs. 1. Introduction The term big data refers to high volume, velocity and variety information which requires new forms of processing. Due to these properties which are referred sometimes as 3 'V's, it becomes difficult to process big data using traditional database management tools [1]. A new challenge is to develop novel techniques and systems to extensively exploit the large volume of data. Many information management architectures have been developed towards this goal [2]. As developing new technologies and increasing the use of big data in several scopes, security and privacy has been considered as a challenge in big data. There are many security and privacy issues about big data [1, 2, 3, 4, 5 and 6]. In [7] top ten security and privacy challenges in big data is highlighted. Some of these challenges are: secure computations, secure data storages, granular access control and data provenance. 2.2 NoSQL The term NoSQL stands for "Not only SQL" and it is used for modern scalable databases. Scaling is the ability of the system to increase throughput when the demands increase in terms of data processing. To support big data processing, the platforms incorporate scaling in two forms of scalability: horizontal scaling and vertical scaling [10]. Horizontal Scaling: in horizontal scaling the workload distributes across many servers. In this type of scalability multiple systems are added together in order to increase the throughput. In this paper we focus on researches in access control in big data and security issues on NoSQL databases. In section 2 we have an overview on big data and NoSQL technologies, in section 3 we discuss security challenges in big data and describe some access control model in big data and in section 4 we discuss security challenges in NoSQL databases. 2. Big Data and NoSQL Overview In this section we have an overview on Big Data and NoSQL. 68 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [2] using data content. In this case the semantic content of data plays the major role in access control decision making. "CBAC makes access control decisions based on the content similarity between user credentials and data content dynamically" [2]. Attribute relationship methodology is another method to enforce security in big data proposed in [3] and [4]. Protecting the valuable information is the main goal of this methodology. Therefore [4] focuses on attribute relevance in big data as a key element to extract the information. In [4], it is assumed that the attribute with higher relevance is more important than other attributes. [3] uses a graph to model attributes and their relationship. Attributes are expressed as node and relationship is shown by the edge between each node and the method is proposed by selecting protected attributes from this graph. The method proposed in [4] is as follow: "First, all the attributes of the data is extracted and then generalize the properties. Next, compare the correlation between attributes and evaluate the relationship. Finally protect selected attributes that need security measures based on correlation evaluation" [4] and the method proposed in [3] is as follow: "All attributes are represented as circularly arranged nodes. Add the edge between the nodes that have relationships. Select the protect nodes based on the number of edge. Determine the security method for protect nodes" [3]. A suitable data access control method for big data in cloud is attribute-based encryption.[1] A new schema for enabling efficient access control based on attribute encryption is proposed in [1] as a technique to ensure security of big data in the cloud. Attribute encryption is a method to allow data owners to encrypt data under access policy such that only user who has permission to access data can decrypt it. The problem with attribute-based encryption discussed in [1] is policy updating. When the data owner wants to change the policy, it is needed to transfer the data back from cloud to local and reencrypt the data under new policy and it caused high communication overhead. The authors in [1] focus on solving this problem and propose a secure policy updating method. Hadoop is an open source framework for storing and processing big data. It uses Hadoop Distributed File System (HDFS) to store data in multiple nodes. Hadoop does not authenticate users and there is no data encryption and privacy in Hadoop. HDFS has no strong security model and Users can directly access data stored in data nodes without any fine grain authorization [13, 16]. Authors in [16] present a survey on security of Hadoop and analyze the security problems and risks of it. Some security mechanism challenges mentions in [16] are large scale of the system, partitioning and distributing files through the cluster and executing task from different user on a single node. In [13] the authors express some of security risk in Hadoop and propose a novel access control scheme for storing data. This scheme includes Creating and Distributing Access Token, Gain Access Token and Access Blocks. The same scheme is also used with Secure Sharing Storage in cloud. It can help the data owners control and audit access to Vertical Scaling: in vertical scaling more processors, more memory and faster hardware are installed within a single server. The main advantages of NoSQL is presented in [11] as the following: "1) reading and writing data quickly; 2) supporting mass storage; 3) easy to expand; 4) low cost". In [11] the data models that studied NoSQL systems support are classified as Key-value, Column-oriented and Document. There are many products claim to be part of the NoSQL database, such as MongoDB, CouchDB, Riak, Redis, Voldermort, Cassandera, Hypertable and HBase. Apache Hadoop is an open source implementation of Google big table [12] for storing and processing large datasets using clusters of commodity hardware. Hadoop uses HDFS which is a distributed file system to store data across clusters. In section 6 we have an overview of Hadoop and discuss an access control architecture presented for Hadoop. 3. Security Challenges and Access Control Model There are many security issues about big data. In [7] top ten security and privacy challenges in big data is presented. Secure computation in distributed framework is a challenge which discusses security in map-reduce functions. Secure data storage and transaction logs discuss new mechanism to prevent unauthorized access to data stores and maintain availability. Granular access control is another challenge in big data. The problem here is preventing access to data by users who should not have access. In this case, traditional access control models have difficulties in dealing with big data. Some mechanisms are proposed for handling access control in big data in [2, 3, 4, 13 and 14]. Among the security issues in big data, data protection and access control are recognized as the most important security issues in [4]. Shermin In [14] presents an access control model for NoSQL databases by the extension of traditional role based access control model. In [15] security issues in two of the most popular NoSQL databases, Cassandra and MongoDB are discussed and outlined their security features and problems. The main problems for both Cassandra and MongoDb mentioned in [15] are the lack of encryption support for data files, weak authentication between clients and servers, simple authentication, vulnerability to SQL injection and DOS attack. It is also mentioned that both of them do not support RBAC and fine-grained authorization. In [5] the authors have a look at NIST risk management standards and define the threat source, threat events and vulnerabilities. The vulnerabilities defined in [5] in term of big data are Insecure computation, End-point input validation/filtering, Granular access control, Insecure data storage and communication and Privacy preserving data mining and analytics. In some cases in big data it is needed to have access control model based on semantical content of the data. To enforce access control in such content centric big data sharing, Content-Based Access Control (CBAC) model is presented in 69 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org service attack because it performs one thread per one client [19] and it does not support inline auditing.[15] Cassandra uses a query language called Cassandra Query Language (CQL), which is something like SQL. The authors of [15] show that injection attack is possible on Cassandra like SQL injection using CQL. Cassandra also has problem in managing inactive connection [19]. their data but the owners need to update the access token when the metadata of file blocks changes. 4. Secutity Issues in NoSQL Databases NoSQL stands for "Not Only SQL" and NoSQL databases are not meant to replace the traditional databases, but they are suitable to adopt big data when the traditional databases do not appropriate [17]. NoSQL databases are classified as Key-value database, Column-oriented database, Document based and Graph database. 4.4 HBase HBase is an open source column oriented database modeled after Google big table and implemented in java. Hbase can manage structured and semi-structured data and it uses distributed configuration and write ahead logging. Hbase relies on SSH for inter-node communication. It supports user authentication by the use of SASL (Simple Authentication and Security Layer) with Kerberos. It also supports authorization by ACL (Access Control List) [17]. 4.1 MongoDB MobgoDB is a document based database. It manages collection of documents. MongoDB support complex datatype and has high speed access to huge data.[11] flexibility, power, speed and ease of use are four properties mentioned in [18] for MongoDB. All data in MongoDB is stored as plain text and there is no encryption mechanism to encrypt data files [19]. All data in MongoDB is stored as plain text and there is no encryption mechanism to encrypt data files. [19] This means that any malicious user with access to the file system can extract the information from the files. It uses SSL with X.509 certificates for secure communication between user and MongoDB cluster and intra-cluster authentication [17] but it does not support authentication and authorization when running in Sharded mode [15]. The passwords are encrypted by MD5 hash algorithm and MD5 algorithm is not a very secure algorithm. Since mongo uses Javascript as an internal scripting language, authors in [15] show that MongoDb is potential for scripting injection attack. 4.5 HyperTable Hypertable is an open source high performance column oriented database that can be deployed on HDFS. It is modeled after Google's big table. It use a table to store data as a big table [20]. Hypertable does not support data encryption and authentication [19]. It does not tolerate the failure of range server and if a range server crashes it is not able to recover lost data [20]. Eventhough Hypertbale uses Hypertable Query Language (HQL) which is similar to SQL, but it has no vulnerabilities for the injection [19]. Additionally there is no denial of service is reported for Hypertable [19]. 4.6 Voldemort 4.2 CouchDB Voldemort [23] is a key value NoSQL database used in LinkedIn. This type of databases match keys with values and the data is stored as a pair of key and value. Voldemort supports data encryption if it uses BerkeleyDB as the storage engine. There is no authentication and authorization mechanism in Voldemort. It neither supports auditing [21]. CouchDb is a flexible, fault-tolerant document based NoSQL database [11]. It is an open source apache project and it runs on Hadoop Distributed File Systems (HDFS) [19]. CouchDB does not support data encryption [19], but it supports authentication based on both password and cookie [17]. Passwords are encrypted using PBKDF2 hash algorithm and are sent over the network using SSL protocol [17]. CouchDB is potential for script injection and denial of service attack [19]. 4.7 Redis Redis is an open source key value database. Data encryption is not supported by Redis and all data stored as plain text and the communication between Redis client and server is not encrypted [19]. Redis does not implement access control, so it provides a tiny layer of authentication. Injection is impossible in Redis, since Redis protocol does not support string escaping concept [22]. 4.3 Cassandra Cassandra is an open source distributed storage for managing big data. It is a key value NoSQL database which is used in Facebook. The properties mentioned in [11] for Cassandra are the flexibility of the schema, supporting range query and high scalability. all passwords in Cassandra are encrypted by the use of MD5 hash function and passwords are very weak. If any malicious user can bypass client authorization, user can extract the data because there is no authorization mechanism in inter-node message exchange.[17] Cassandra is potential for denial of 4.8 DynamoDB DynamoDB is a fast and flexible NoSQL database used in amazon. It supports both key value and document data model [24]. Data encryption is not supported in Dynamo but the communication between client and server uses https protocol. 70 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Some researchers presented new access control model for big data which was introduced in this paper. In the last section we described security issues in NoSQL databases. As it was mentioned the most of NoSQL databases has the lack of data encryption. To have a more secure database it is needed to encrypt sensitive database fields. Some of databases have vulnerability for injection. It is needed to use sufficient input validation to overcome this vulnerability. Some of them have no authentication mechanism and some of them have weak authentication mechanism. So to overcome this weakness it is needed to have strong authentication mechanism. CouchDB uses SSL protocol, Hbase uses SASL and Hypertable, redis and Voldemort has no authentication and the other databases has weak authentication. MongoDB and CouchDB are potential for injection and Cassandra and CouchDB are potential for denial of service attack. Table 1 briefly shows this comparison. Authentication and authorization is supported by dynamo and arequests need to be signed using HMAC-SHA256 [21]. 4.9 Neo4J Neo4j [25] is an open source graph database. Neo4j does not support data encryption and authorization and auditing. The communication between client and server is based on SSL protocol. [21]. 5. Conclusion Increasing the use of NoSQL in organization, security has become a growing concern. In this paper we presented a survey on security and privacy issues in big data and NoSQL. We had an overview on big data and NoSQL databases and discussed security challenges in this area. Due to the high volume, velocity and variety of big data, traditional security models have difficulties in dealing with such large scale data. Table 1: The Comparison between NoSQL Databases Authentication Authorization Data Encription Auditing Communication protochol Document Not Support Not Support Not Support - SSL CouchDB Document Support - Not Support - SSL Cassandra Key/Value Support Not Support Not Support Not Support SSL Column Oriented Support Support Not Support - SSH Not Support - Not Support - Not Support Tiny Layer Not Support Not Support Support Not Support Support - - Not Support DB/Criteria Data Model MongoDb Hbase HyperTable Voldemolt Redis DynamoDB Neo4J Column Oriented Key/Value Key/Value Key/Value Document Graph Potential for attack Script injection Script injection and DOS Script injection (in CQL) and DOS Not reoprt for DOS and injection Data Model - - Not Support Not Support Not Encrypted - Not Support - https - Column Oriented Key/Value Key/Value Key/Value Document Not Support Not Support SSL - References K.Yang, Secure and Verifiable Policy Update Outsourcing for Big Data Access Control in the Cloud, Parallel and Distributed Systems, IEEE Transactions on , Issue 99, 2014 [2] W.Zeng, Y.Yang, B.Lou, Access control for big data using data content, Big Data, IEEE International Conference on, pp. 45-47, 2013 [3] S.Kim, J.Eom, T.Chung, Big Data Security Hardening Methodology Using Attributes Relationship, Information Science and Applications (ICISA), 2013 International Conference on, pp 1-2, 2013 [4] S.Kim, J.Eom, T.Chung, Attribute Relationship Evaluation Methodology for Big Data Security, IT Convergence and [1] [5] [6] [7] [8] Document Document Key/Value Column Oriented Graph Security (ICITCS), 2013 International Conference on, pp 1-4, 2013 M.Paryasto, A.Alamsyah, B.Rahardjo, Kuspriyanto, Big-data security management issues, Information and Communication Technology (ICoICT), 2nd International Conference on, pp 5963, 2014 J.H.Abawajy,A. Kelarev, M.Chowdhury, Large Iterative Multitier Ensemble Classifiers for Security of Big Data, Emerging Topics in Computing, IEEE Transactions on, Volume 2, Issue 3, pp 352-363, 2014 Cloude Security Allience, Top Ten Big Data Security and Privacy Challenges, www.cloudsecurityalliance.org, 2012 K. Zvarevashe, M. Mutandavari, T. Gotora, A Survey of the Security Use Cases in Big Data, International Journal of 71 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] Innovative Research in Computer and Communication Engineering, Volume 2, issue 5, pp 4259-4266, 2014 M.D.Assuncau, R.N.Calheiros, S.Bianchi, A.S.Netto, R.Buyya, Big Data computing and clouds: Trends and future directions, Journal of Parallel and Distributed Computing, 2014 D.Singh, C.K.Reddy, A survey on platforms for big data analytics, Journa of Big Data, 2014 J.Han, E.Haihong, G.Le, J.Du , Survey on NoSQL Database, Pervasive Computing and Applications (ICPCA), 2011 6th International Conference on, pp 363-366, 2011 F.Chang, J.Dean, S.Ghemawat, W.C. Hsieh, D.A. Wallach, Bigtable: A Distributed Storage System for Structured Data, Google, 2006 C.Rong, Z.Quan, A.Chakravorty, On Access Control Schemes for Hadoop Data Storage, International Conference on Cloud Computing and Big Data, pp 641-645, 2013 M. Shermin, An Access Control Model for NoSQL Databases, The University of Western Ontario, M.Sc thesis, 2013 L.Okman, N.Gal-Oz, Y.Gonen, E.Gudes, J.Abramov, Security Issues in NoSQL Databases, Trust, Security and Privacy in Computing and Communications (TrustCom), IEEE 10th International Conference on, pp 541-547, 2011 M.RezaeiJam, L.Mohammad Khanli, M.K.Akbari, M.Sargolzaei Javan, A Survey on Security of Hadoop, Computer and Knowledge Engineering (ICCKE), 2014 4th International Conference on , pp 716-721, 2014 A.Zahid, R.Masood, M.A.Shibli, Security of Sharded NoSQL Databases: A Comparative Analysis, Conference on Information Assurance and Cyber Security (CIACS), pp 1-8, 2014 A.Boicea, F.Radulescu, L.I.Agapin, MongoDB vs Oracle database comparison, Emerging Intelligent Data and Web [19] [20] [21] [22] [23] [24] [25] Technologies (EIDWT), 2012 Third International Conference on, pp 330 – 335, 2012 19P.Noiumkar, T.Chomsiri, A Comparison the Level of Security on Top 5 Open Source NoSQL Databases, The 9th International Conference on Information Technology and Applications(ICITA2014) , 2014 A.Khetrapal, V.Ganesh, HBase and Hypertable for large scale distributed storage systems, A Performance evaluation for Open Source BigTable Implementations, Dept. of Computer Science, Purdue University, http://cloud.pubs.dbs.uni-leipzig.de/node/46, 2008 K.Grolinger, W.A.Higashino, A.Tiwari,M.AM Capretz, Data management in cloud environments: NoSQL and NewSQL data stores, Journal of Cloud Computing: Advances, Systems and Applications, 2013 http://redis.io/topics/security http://www.project-voldemort.com http://aws.amazon.com/dynamodb http://neo4j.com Ebrahim Sahafizadeh, B.S. Computer Engineering (Software), Kharazmi University of Tehran,2001, M.S. Computer Engineering (Software), ran University of Science & Technology, Tehran, 2004. Ph.D student at Isfahan University. Faculty member, Lecturer, Department of Information Technology, Payame Noor University , Boushehr. MohammadAli Nematbakhsh, B.S. Electrical Engineering , Louisiana Tech University, USA, 1981, M.S. Electrical and Computer Engineering. University of Arizona, USA, 1983, Ph.D. electrical and Computer Engineering, University of Arizona, USA, 1987. Micro Advanced Computer, Phoenix, AZ, 1982-1984, Toshiba Co, USA and Japan, 1988-1993, Computer engineering Department, university of Isfahan, 1993-now 72 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Classifying Protein-Protein Interaction Type based on Association Pattern with Adjusted Support Huang-Cheng Kuo and Ming-Yi Tai Department of Computer Science and Information Engineering National Chiayi University Chia-Yi City 600, Taiwan [email protected] Keywords: Protein-Protein Interaction, Association Pattern Based Classification, Type Imbalance some small transactions from a protein complex, and each small transaction contains the residues which are geographically close to each other. The binding surface of a protein complex is usually curve. So, there have some residues of a protein with concave shape binding site and others are on the other protein with convex shape binding site. A transaction is a tuple <R, L>, where R is a set of residues of a protein, L is a set of residues of the other protein. Residues of a transaction are geographical close to each other. Patterns from obligate protein complexes and from transient protein complexes are mined separately [1]. In this paper, we assume proteins are in complex form. However, with the association patterns, proteins can be indexed under the patterns. So that biologists can quickly screen proteins that interact with the certain type of interaction. 1. Introduction 2. Related Works Protein-protein interaction refers to an event generated on the change in physical contact between two or more proteins. Protein-protein interaction occurs when a number of proteins combine into an obligate protein complex or a transient protein complex. An obligate complex will continue to maintain its quaternary structure and its function will continue to take effect. A transient complex will not maintain its structure. It will separate at the end of its function. Protein-protein interaction occurs mainly on the binding surface of the proteins. The residues on the binding surface play an important role for deciding the type of protein-protein interaction. The residue distribution affects the contacting orientation and thus determines the binding energy which is important in interaction type. In this paper, an association pattern method is proposed for classifying protein-protein interaction type. A transaction is instead of considering all the residues on the binding surface of a protein complex. We generate The ultimate goal of this paper is user input transient protein binding proteins, and then quickly screened out an experimental biological experimenter direction from the data library. As for how to predict protein interaction type, researchers have proposed method using machine learning classification methods to design the system module. Mintseris et al for protein complexes can identify whether their prediction classification of information depends only limited participation in Pair of two proteins interact in order for the quantity of various atoms, called Atomic Contact Vector. There is a good accuracy, but there are two drawbacks. (1) Feature vector (171 dimensions), there will curse of dimensionality problem. (2) Focus only on contact with the atom, it did not consider the shape of the contact surface. The shape of the contact surface of the protein affects the contacting area and the types of atom contact Abstract Proteins carry out their functions by means of interaction. There are two major types of protein-protein interaction (PPI): obligate interaction and transient interaction. In this paper, residues with geographical information on the binding sites are used to discover association patterns for classifying protein interaction type. We use the support of a frequent pattern as its inference power. However, due to the number of transient examples are much less than the number of obligate examples, therefore there needs adjustment on the imbalance. Three methods of applying association pattern to classify PPI type are designed. In the experiment, there are almost same results for three methods. And we reduce effect which is correct rate decreased by data type imbalance. 73 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org rules, such as SVM, has 99% correct rate, and knearest-neighbor method also has about 93% accuracy[13]. Lukman et al divided interaction into three categories: crystal packing, transient and obligate. 4,661 transient and 7,985 obligate protein complexes are in order bipartite graph pattern mining complexes of each category, and find style single binding surface dipeptide. Find out which style or Patches, locate the joint surface, and can bring good accuracy whether protein interactions. Some people use the opposite operation, a collection of known protein acting plane. We want to find those proteins which have similar effects because the first know what is the role of surface interacted with each other exist. But it is possible to be able to know relationship exists for protein to protein. [2,3]. It is a popular field of study on protein complexes in addition to the recognition as a research outside the pharmacy. In pharmaceutical drug design research, the main goal is analyzing protein-protein interaction[4,5]. Pharmaceutical drug design research intends to find the protein that is located in a position gap, and the gap is mainly protein or protein-bound docking. In the protein binding site, there is information, such as shapes, notch depth and electrical distribution. The protein binding site is the main location of the occurrence of disease organisms, and the location is a place where compound produced protein chemistry and mutual bonding place. Therefore, when researchers design a drug, they look for existing molecules or the synthesis of new compounds. When a compound is placed in the protein gap, we must try to put a variety of different angles to constantly rotate. Looking for as much as possible fill the gap and produce good binding force between molecules. So, we can find a compound capable of proteins that have the highest degree of matching notches. This is called docking. Protein-protein interaction network can help us to understand the function of the protein[6,7]. You can understand the basic experiment to determine the role of the presence of the protein, but the protein due to the huge amount of data. We are not likely to do it one by one experiment. So predicting interactions between proteins has become a very important issue. In order to predict whether there has interaction between the protein situations more accurately [8]. So Biologists proposed using protein combination to increase the accuracy. The joint surface between the protein and the protein interacting surface is called protein domain. Domain Protein binding protein is the role of surface functional units. Usually a combination of surface has more than one domain presence, and combined with the presence of surface property which is divided into the following categories: hydrophobicity, electrical resistance, residual Kitt, shape, curvature, retained residues[9, 10, 11]. We use information of residues. Park et al also use classification association rules prediction interaction. The interaction into Enzymeinhibitors, Non Enzyme-inhibitors, Hetero-obligomers, Homo-obligomers and other four categories[12], the total 147. Association rule is used in conjunction face value of 14 features, as well as domain, numerical characteristics such as average hydrophobicity, residue propensity, number of amino acids, and number of atoms. There is about 90 percent correction rate, but the information has the same way. Other non-association 3. Data Preparation 3D coordinate position of the plan of proteins derived from the RCSB Protein Data Bank. Identification of protein complexes, there are several sources: 1. 209 protein complexes collected by Mintseris and Weng [3]. 2. Protein complexes obtained from the PDB web site[14]. Then type of the complexes is determined by using NOXclass website. NOXclass uses SVM to classify the protein-protein interaction of three types into biological obligate, biological transient and crystal packing. We keep only the protein complexes which as classified as biological obligate and biological transient. The accuracy rate is claimed to be about 92%. So, we use the data classified by NOXclass as genuine data for experiment. We collected total 243 protein complexes [15] by this way. 3.1 The Binding Surface Residues A protein complex is composed of two or more proteins, where in PDB[14] each protein is called a chain. The all the chains in a protein complex share a coordinate system, and the coordinates of each chain of each residue sequentially label in a number of the more important atoms. Because it is a complex of a common coordinate system, so that the relative position is found between the chains. If there are two chains bind together by the chain of residue position determination, but no residues are indicated at the bonding surface on[16]. It is therefore necessary to further inquiries by other repositories or algorithms judgment. There have been many studies on protein sequence data to predict which residues are on the binding surface[17]. In our research, the atom-to-atom distance between two 74 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org residues is used to decide whether the two residues which are on the binding surfaces. They are binding surface residues if there exists an atom-to-atom distance which is less than a threshold. The distance threshold is 5Å in this paper[18,19,20] . Input 100 Input pdb data Operation confidence Search residue sets pair Confidence > 0.6 Yes Transaction No Support >1% Have same rule No No Yes Select Yes Get association rule Delete Finish rule classify Fig 1. Associative Classification Mining We input a dataset of PDB files[14], then find the residues on the binding site for each complex and get a pair of residue sets, one set on the convex side, the other one on the other side. And partition each of the pairs of residue sets into transactions for association rule mining in next box. Finally if the transaction's value of supper is less than 1%, then delete this transaction. Delete Fig 2. Applying the rules to classify Taking association rule operation value for PDB file[14] called confidence. If the value of confidence is less than 0.6, delete this rule. Next check have same rule with different type, if have same rule, delete lower confidence rule. 3.2 Obtaining Data Frequent pattern mining results can be obtained such as: identification of protein complexes in the same body, which is electrically common to the residues in the concave joint surface, and hydrophilic (or hydrophobic) residue at the convex joint surface. Association rule mining results can be obtained, such as: polar residues 75 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org association rule mining we can get rule: {phe, ser} → {arg} , support for the rule of 1.9%, confidence is 90%. After exploration, it identify with the non-binding protein complex identification of amino acid side connected to the rules. It can assist in predicting the style to get a likelihood classification combined with another side effect of the combination of face recognition occurs. If one party has a combination of surface phe and ser. The other party has arg, and then the binding surface increases the likelihood of identification. But if the two sides should also consider combining amino acid side of the amino acid pattern of non-compliance with the identification of the joint surface. The likelihood of this occurrence to identify the combination of surface and reduced. In addition, detailed rules amino acid position for the application of the rules is likely to affect, such as: if ser phe and the distance to the amino acid level, it is very far away. Even if there is another combination of surface arg. The applicability of this rule may play on a discount of, on the contrary. If it is very close distance, the influence of this rule should be raised. We will consider the overall impact is to identify a set of joint surface when the amino acid pattern recognition and non-recognition of the joint surface binding amino acid pattern in the surface of the judge[22,23]. Obtain association rules method, divided into two steps: 1. Delete unimportant or conflict association rules. 2. Select the association rules, set for unknown objects. And related forms of association rule is X => C, X is the project set (also called itemset), C is a category. Association rules in the form of <X, Y> => C, X and Y are itemsets, representing convex and convex surface binding residues; C is a correlation between categories[24]. on the concave joint surface and hydrophilic (or hydrophobic) residue at the convex joint surface. The identification of protein complexes mostly is interaction. Combination of surface materials can have physical and chemical properties of amino acids. As well as numerical features such as accessible surface area (ASA). The appropriate numeric features discrete (discretize) for the interval, as a project (item) mining of association rules. At this stage, we just take the residual basic body styles and frequently used as input data mining of association rules. We combine two protein complexes uneven surface residues projected on the surface of the joint surface of the cross to a radius of 10 Å circular motion in the transverse plane. The radius of 10 Å successive increases in a circular motion to form concentric rings[21]. Each ring will cut the number of between zones of equal area (sector), and different ring every area roughly equal to the formation of residues in each district a deal. This method will be divided residues from the past in the same transaction. But the disadvantage is that the district boundary residues are rigidly assigned to a transaction that is on the boundary of two similar residues are divided into different deal. Another way for the direct use of the tertiary structure coordinates to each binding surface residues as a benchmark. In concave surface of combination site. For example, take one of the residues r, the same as in the concave and r similar residues put together, then convex. The similar residues with r is added and assigned to the same transaction. The advantage is that residues close to each other are put into a transaction. But the drawback is that a residue may repeatedly appears in some transactions. Then we find on the amount of data that is significantly the number of type biological transient less than obligate, which causes production rules and calculations during supper. The value of biological transient is underrated, so we have to do to adjust the value of biological transient. So biological obligate and biological transient are at the fair situation. 4. Association Rules Deletion Data for the transaction or relation, in the training data set (hereinafter referred to as DB) data attach each category. The following instructions to the P and N two categories. For example, Arising class association rule (hereinafter referred to as CAR) format X => Y, X is an item set, Y is a type. In [25] algorithm, which depend on the sort of confidence class association rule. The pattern with the same confidence are sorted according their supports. Then the class association rule is according to the sort order of selection. The selection process is that the data base in line with the current class association rule (called r) case deletion of the conditions of. Data base case after delete the called DB '. Suppose r of category P, 3.3 Associative Classification Rule Various protein complexes bind frequency distribution of different surface amino acids, which the reason we believe that the association rules can be used as the basis to predict classification. In addition, the combination of surface irregularities are made of a complex combination of the two surfaces. Using arg amino acids for example, in the identification of the complex, if there is a combination of concave and phe ser, then there will be 90% across arg, there is the 76 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org in line for the case N R condition but the number of classes, for r the error; case DB 'is determined by a majority judgment error, assume that the majority of Class P case, the DB' in the number N class called DB 'of the error. So every pick a class association rule, there will be one pair of class association rule of error, and choose class association rule to the whole process lasted until the lowest error Its algorithm is as follows: 1 R = sort(R); 3. 2 for each rule r in R in sequence do 3 temp = empty; 4 for each case d in D do 5 6 6. Support Adjustment if d satisfies the conditions of r then store d.id in temp and mark r When predicting PPI type, we find that no matter which method of calculation the prediction results are almost always obligate type. There are almost all obligate data rule, transient data rule almost nothing. We judge because the gap between the obligate data and transient quantity data, resulting in a lower number of transient rule, more likely to be filtered out, so we focused on a number of imbalances do numerically adjustment. The following formula: C( x ) = P( x ∩obligate ) * R / if it correctly classifies d; 7 end if r is marked then 8 9 temp from D; insert r at the end of C; delete all the cases with the ids in 10 11 C; select a default class for the current C; compute the total number of errors of 12 obligate two type. Let Ri is descending order of confidence value rule set. Determine which type large quantity for the top few rule in set. If object type large, we surmise this object type is obligate, else we surmise this object type is transient. The number of qualified rule: If this object contains a number of rules Ri and Rj, Ri is obligate type rule set and Rj is non- obligate type rule set. If the number of rule in Ri is large than Rj, then surmise this object is obligate type, if not surmise this object is transient type. (P( x ∩obligate ) * R + P( x ∩non-obligate ) ) (1) Let's R is assumed that the ratio of transient to obligate. X is a rule, denote this PPI is obligate end denote and this PPI contain rule x. 13 end 14 Find the first rule p in C with the lowest total number of errors and drop all the rules after p in C; 15 Add the default class associated with p to end of C, and return C (our classifier). this PPI is transient. Table1. The number of non-obligate rules. Factor Before support adjustment After support adjustment 5. Applying Rules for Classification When the classification of an unknown category of object, there are some methods of selecting rules: 1. Confidence sum 2. Higher confidence 3. The number of qualified rule The methods are as follows: 1. Confidence sum: If this object contains a number of rules Ri and Rj, Ri is obligate type rule set and Rj is non- obligate type rule set. Let X is sum of confidence for Ri, Y is sum of confidence for Rj. If X > Y, we surmise this object type is obligate, else we surmise this object type is transient. 2. Higher confidence: If this object contains a number of rules R, R is rule set contain obligate and non- 1.0 2 1.1 1 1.2 1 1.3 1 1.4 1 1.5 0 1.6 0 1.7 1 1.8 1 1.9 2 11 14 14 18 34 64 95 17 3 29 1 44 9 This table shows the number two transient rules in range factor from 1.0 to 2.0. Before the change of the number of transient rules are rare and some cases do not even have. After the change, see table 1 the number of transient rules has increased after support adjustment. 77 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org In figure 3, we find that is low correct rate before data counterpoise. Because the number of non-obligate rule is more less than obligate rule number. From the figure 4, the results of the number of qualified rule and confidence sum rule number the difference of two methods is not large. Because the confidence will be greater the more acceptable when the number of its rule, cause results not dissimilar large. High confidence at lower accuracy rate method beginning, because at factor size is relatively small number of transient rule is not much. It is easy to determine when not to judge him, because of high confidence. The number of the back of transient rule is changed for a long time. It increases the accuracy by High confidences before making a judgment. 7. Experiment and Discussion 8. Conclusions The amount of protein data is enormous, coupled with environmental variation factors of uncertainty. It takes a lot of time and money to determine protein-protein interaction in wet lab. So there are many experts and scholars toward using known information to predict protein interactions situation, in order to reduce the amount of protein test objectives. We use a class association rule method for classifying protein-protein interaction type. And we compared several screening methods about screening associated rules. Due to type imbalance, where there are much more obligate protein complexes than transient protein complexes, the interesting measures of the mined rules are tortured. We have designed a method to adjust this effect. The proposed method can further be used to screen proteins that might have a certain type of protein-protein interaction with a query protein. For biologists, it may take much less time to explore; also it saves time to experiment. Even for pharmaceutical research and development, it has brought many benefits. Mainly proteins and protein interactions experimentally really have to spend a lot of time and money. If a system can quickly provide a list of the list of subjects, there will be a great help. Fig 3 The correct rate of non-obligate data prediction Fig. 4 The result of proposed method. References [1] SE Ozbabacan, HB Engin, A Gursoy, O Keskin, “Transient Protein-Protein Interactions,” Protein Engineering, Design & Selection, Vol. 24, No. 9, pp. 63548, 2011. [2] Ravi Gupta, Ankush Mittal and Kuldip Singh, “A TimeSeries-Based Feature Extraction Approach for Prediction 78 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org of Protein Structural Class,” EURASIP Journal on Bioinformatics and Systems Biology, pp. 1-7, 2008. 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ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Digitalization Boosting Novel Digital Services for Consumers Kaisa Vehmas1, Mari Ervasti2, Maarit Tihinen3 and Aino Mensonen4 1 VTT Technical Research Centre of Finland Ltd Espoo, PO BOX 1000, 02044, Finland [email protected] 2 VTT Technical Research Centre of Finland Ltd Oulu, PO BOX 1100, 90571, Finland [email protected] 3 VTT Technical Research Centre of Finland Ltd Oulu, PO BOX 1100, 90571, Finland [email protected] 4 VTT Technical Research Centre of Finland Ltd Espoo, PO BOX 1000, 02044, Finland [email protected] successful themes for economic growth: data is often considered as a catalyst for overall economy growth, innovation and digitalization across all economic sectors. For example, in Europe the Big Data sector is growing by 40% per year, seven times faster than the IT market [3]. Abstract Digitalization has changed the world. The digital revolution has promoted the Internet, and more recently mobile network infrastructure, as the technological backbone of our society. Digital technologies have become more integrated across all sectors of our economy and society, and create novel possibilities for economic growth. Today, customers are more and more interested in value-added services, compared to the basic products of the past. Novel digital services, as well as the use of mobile services, has increased both at-work and during free time. However, it is important to understand the needs and expectations of the end users and develop future services with them. This paper focuses on pointing out the importance of user involvement and co-design in digital service development and providing insights on transformation caused by the digital revolution. Experiences and effects of user involvement and codesign are introduced with details via two case studies from the traditional retail domain. Keywords: digital services, digitalization, user involvement, codesign, retail. Digitalization is affecting people‘s everyday lives, and changing the world. The pervasive nature of technology in consumers‘ lives also causes a rapid change in the business landscape [4]. The value of the ICT sector‘s manufacturing and services will increase faster than the world economy on average [5]. Thus, companies have to move their business into digital forms. Business models must change to support and improve new business opportunities, which are created together with the services. In order to build up an excellent digital service that meets the customers‘ needs, participatory design of the service is inevitable [6]. To be successful, innovative solutions must take into account opportunities provided by new technology, but they cannot lose sight of the users. In practice, companies have understood how important it is to understand the needs and expectations of the end users of the product or service. Users are experts on user experience and thus are a significant source of innovation [7]. Involving different stakeholders in the value chain, from the very start of the development process, increases customer acceptance, gives the developers new development ideas and gives the users feelings that their voices have been heard. The interaction with the customer is the key issue. That is, keeping customers satisfied in a way that they feel that the service provider listens to them and appreciates their 1. Introduction The digital revolution is everywhere and it is continually changing and evolving. Information technology (IT) innovations, such as the Internet, social media, mobile phones and apps, cloud computing, big data, e-commerce, and the consumerization of IT, have already had a transformational effect on products, services, and business processes around the world [1]. In fact, information and communications technology (ICT) is no longer a specific sector, but the foundation of all modern innovative economic systems [2]. Digitalization is one of the 80 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org opinions and activities is of major importance. This will make it possible for companies to obtain and keep loyal customers. [8] 2.1 Digital Services Boosting the Finnish Economy In the beginning of the DS program DIGILE, Finnish industry and Academia of Finland (http://www.aka.fi/en) together identified four themes which would lead the Finnish economy towards having the best means to reach an advantageous position in the global market for mobile services. The themes were 1) small and medium enterprises (SME) services, 2) financial services, 3) educational services, and 4) wellness services. The main aim of the DS program was to create and begin to implement various digital services, service platforms and technologies which promote new or enhanced services, as well as to ensure maintenance of new services in selected areas. The structure of the DS program is presented in Figure 1. This paper focuses on pointing out the importance of user involvement and co-design in digital services development and providing insights of transformation caused by digital revolution. Experiences and effects of user involvement and co-design are introduced with details via two case studies from the traditional retail domain. The research was done as a part of large Digital Services (DS) program (http://www.digital-services.fi) facilitated by DIGILE (http://www.digile.fi), one of Finland‘s Strategic Centers for Science, Technology and Innovation. DIGILE points out that ICT-based digital services are the most important way to provide added value to customers. Thus, DIGILE is focused on promoting the development of digital service know-how for business needs. In the DS program, work was conducted in a true partnership model, meaning that the program provided a pool of complementary platforms where partners shared and trialed their innovations and enabler assets. The mission was accomplished by creating new innovative services in these selected sectors and by recognizing the need of enablers in their context. The ecosystem thinking played a central role during the whole program. The case studies described in this paper, Case A and Case B, are introduced in detail for illustrating user involvement and co-design while developing new digital services for a traditional retail sector. In Case A, novel omnichannel services for the customers were integrated into the retail processes to better serve and meet the needs of the store‘s rural customers closer to their homes. Customers living in rural areas were known not to have access to the larger selections of the retailer‘s online stores. The second, Case B, aimed to understand consumer attitudes towards novel digital service points in hypermarkets. Customers were able to test the first version of a novel user interface to be used in digital service points. The case studies emphasized the importance of user involvement and co-design while developing new digital services. Fig. 1 The structure of the Digital Services program. This paper is structured in the following way. In the second chapter background information about the DIGILE Digital Services program and digitalization in general are given. Also, relevant literature concerning the retail sector and the context of the case studies are introduced. The third chapter presents the research approaches used with the two case studies. In the fourth chapter case study findings are introduced and discussed. Finally, in the fifth chapter the main findings are summarized and concluded. The key objectives for the SME services were optimizing service creation tools for SMEs and sharing of know-how in service building to enable a new class of service development. The SME theme targeted creation of a pool of companies implementing key services by or for the SME sector. SMEs supported the whole services ecosystem by utilizing and trialing service platforms offered by the program. A pull of additional platform features was created, and SMEs acted to create new service products for their business. Rapid prototyping and iterative research methods were utilized. 2. Background In the case of financial services the program concentrated on services and service enablers which bring added value to the companies, customers, as well as to consumers, and linked money transactions and financial services smoothly to the ecosystem market. The goal was to introduce mechanisms and platforms for service developers, enabling financial transactions in the services and to develop safe and flexible trust enablers, as well as cost- In this chapter, the DS program is introduced with some examples of developed digital services in order to build a complete picture of where the case studies were carried out. After that, an overview of digitalization and its‘ effect on digital services are presented. Finally, digitalization in the retail sector, the environment of our case studies, is introduced in detail. 81 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org changes the world and affects people‘s everyday lives. The huge impact of digitalization and the Internet will be felt in different industrial and associated sectors, for example, 3D printing, smart city services (e.g. lighting control, temperature optimization), predictive maintenance solutions, intelligent logistics, smart factories, etc. efficient banking and payment tools, for both existing and new innovative mobile services. The goal of educational services was to increase the utilization and availability of e-learning materials and services in education. It was not only concentrated on support for mobile and pervasive learning, but on high quality services that could be easily integrated into everyday processes of the ordinary school day. User perspectives played an important role; this was seen as especially important in cases that aim at the global market or developing services for challenged learners. Digitalization also means that businesses make use of electronic information exchange and interactions. For example, digitalization in factories allows end-to-end transparency over the entire manufacturing process, so that individual customer requirements can be implemented profitably and the produced solutions managed throughout their life cycle. Existing businesses can be modernized using new technologies, which potentially also generate entirely new types of businesses. Evans and Annunziata [10] highlight the promise of the Industrial Internet by stating that it is the 3rd innovation wave – after the Industrial Revolution (1st wave) and the Internet Revolution (2nd wave). The growing importance of context-awareness, targeting enriched experience, intuitive communication services and an increasingly mobile society, requires intelligent services that are smart, but invisible to users. Hernesniemi [11] argued that the value of the ICT sector‘s manufacturing and services will increase faster than the world economy on average. For example, e-Commerce is growing rapidly in the EU at an average annual growth rate of 22%, surpassing EUR 200 billion in 2014 and reaching a share of 7% of total retail sales [12]. In the case of wellness services the aim was to create a wellness ecosystem with common platform access and the capability to develop enablers and tools for integrating different categories of value adding services and technologies. It was also targeted towards developing components and capabilities for integrating technologies for automatic wellness data collection. Data analysis will be facilitated by developing and enabling the integration of tools for professional wellness data analysis and content delivery. During 2012-2015, 85 organizations (53 SMEs, 19 large companies and 13 research organizations) in total participated in the DS program. The program exceeded the goals by achieving 27 highlighted new services and 18 features. In addition, three new companies were established. One of the successful examples of results achievement is Personal Radio. This offers consumers new services and personal content from different sources based on recommendation engine technology. The ecosystem thinking was an enabling asset: there have been several companies involved in trying to create the service, e.g., companies to take care of content production and delivery, speech synthesis, audio search, content analysis, payment system, concept design, user interface, business models, user experience and mobile radio player. In addition, in the wellness services domain several wellbeing services were developed. For example, novel mobile services to prevent illnesses, such as memory disorder or work-related musculoskeletal disorder, were developed. Novel option for traditional marital therapy and couching methods is now available in mobile also. In this paper, two pilot cases are introduced as examples of digitalization and developing digital services in the retail sector. In the digital economy, products and services are linked more closely to each other. The slow economic growth during recent years has boosted the development of product-related services even more – these services have brought increasing revenue for the manufacturing companies in place of traditional product sales. The global market for product and service consumption is steadily growing. Today consumers are key drivers of technology and change as new digital tools, e.g., comparison websites, social media, customization of goods and services and mobile shopping, have empowered them [13]. Customers are more and more interested in value-added services compared to the basic products themselves. Now, companies around the world are not only willing to use digital technologies to obtain transformation—they must [14]. Companies are working towards achieving digital transformation, but still most are lacking experience with emerging digital technologies and they are skeptical. The key issue is to respond effectively and quickly to newly available technologies in order to gain better customer experiences and engagement, streamlined operations and new lines of business. Accordingly, digital services are a strong global trend in the world: long-term 2.2 Digitalization Effects on Services and Business The digital revolution has promoted the Internet and more recently mobile networks infrastructures as the technological backbone of our society. The Internet and digital technologies have become more integrated across all sectors of our economy and society [9]. Digitalization 82 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org development is moving the weight of economic value creation from agriculture, to goods, and then services. The service sector is the fastest growing segment of global economies. Figure 2 illustrates the trend in the USA. of these displays is to provide better service for customers and promote sales. From a retail perspective, these displays can be seen as one of the many channels that aim to capture people‘s attention and affect their customer behavior. ICT has a remarkable impact on the development of services; ICT enables completely new services, increases the efficiency of service production, enhances the availability of services, and increases the profitability of service business. Kettunen et al. [15] have identified six megatrends in ICT and ICT enabled services; 1) dataintensiveness, 2) decentralized system architectures, 3) fusion of real and virtual, 4) disappearing (or hidden) human interface, 5) web-based organization of work and life, and 6) increasing need to manage social robustness. For example, the advantage of the data-intensiveness is that the service providers can automatically collect and analyze a large amount of customer or process data, and also combine it with other data that is available free of charge. This helps service providers to develop their services, e.g., by customizing the services and creating new ones. 2.3 Digitalization of the Retail Sector The retail sector is considered one of the most rapid technology-adoptive sectors (e.g., [19]). Over the years, retailers have learned how to design their stores to better meet shoppers‘ needs and to drive sales. In addition, the technical infrastructure that supports most retail stores has grown enormously [20]. The retail industry has evolved from traditional physical stores, through the emergence of electronic commerce, into a combination of physical and digital channels. Seeing the future of retailing is quite complex and challenging; busy customers expect that companies use innovative approaches to facilitate their shopping process efficiently and economically, along with providing value-added shopping experiences. People no longer only go shopping when they need something: the experience of shopping is becoming more important [21]. There are a number of challenges and opportunities retailers face on their long-term radar, such as changes in consumer behavior and consumer digitalization. These drivers affecting the retail sector should be a key consideration for retailers of all shapes and sizes [22]. It is likely that the power of the consumer will continue to grow [23], and from the demand side, consumers will be empowered to direct the way in which the revolution will unfold [24]. The focus on buying behavior is changing from products to services [25]. Thus, the established retailers will need to start considering how they can more effectively integrate their online and off-line channels to provide customers with the very highest levels of service. Fig. 2 Long term industry trends [16]. The use of mobile services has increased both at work and during free time, and social communities are increasingly formed. People are able and willing to generate content and the line between business and private domains is increasingly blurred [17]. The idea of everybody having their own personal computer is being reborn and has evolved into everyone having their own personal cloud to store and share their data and to use their own applications [18]. This is driving a power shift away from personal devices toward personal services. It is now widely recognized that the Internet‘s power, scope and interactivity provide retailers with the potential to transform their customers‘ shopping experiences, and in so doing, strengthen their own competitive positions [26]. Frost & Sullivan [27, 28] predicts that by 2025, nearly 20% of retail will happen through online channels, with global online retail sales reaching $4.3 trillion. Thus, retailers are facing digitalization of the touch-point and consumer needs [29]. By 2025, 80 billion devices will connect the world with each person carrying five connected devices [30]. Mobile and online information technology make consumers more and more flexible in terms of where and how they wish to access retailer information and where and how to purchase products. Consumer behavior is changing as a growing number of smarter, digitally-connected, price-conscious consumers Currently, digital signage is widely used in different environments to deliver information about a wide array of topics with varying content formats. Digital signs are generally used in public spaces, transportation systems, sport stadiums, shopping centers, health care centers etc. There are also a growing number of indoor digital displays in shopping centers and retail stores. The underlying goal 83 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org All these needs and requirements must come together as a unified, holistic solution, and retailers should be able to exploit the channel-specific capabilities in a meaningful way [43]. exploit multiple shopping channels, thus making the multichannel retail approach an established shopping behavior [31]. Described as channel agnostic, modern consumers do not care whether they buy online, via mobile or in-store as long as they get the product they want, when they want it at the right price. A new behavior of test-andbuy-elsewhere is becoming more common [32] and retailers must adapt to the buying behavior of these ―channel-hoppers‖ [33]. Aubrey and Judge [34] talk about ‗digital natives‘ who are highly literate in all things digital, and their adoption of technology is easy and distinctive. 3. Developing New Digital Services In this chapter the research approaches for our case studies are introduced in detail. The case studies emphasize user involvement and co-design while developing new digital services. However, simply ―adding digital‖ is not the answer for retailers – yet that is an approach too often taken [35]. For traditional retailers to survive, they must pursue a strategy of an integrated sales experience that blends online and instore experiences seamlessly, leading to the merger of a web store and a physical store [36]. According to Frost & Sullivan [37], the retail model will evolve from a single/multiple channel model to an integrated hybrid cross-channel model, identified as bricks and clicks. Thus, shoppers of the future float seamlessly across mobile, online and real-world platforms [38]. 3.1 Case Study A In this research context the retailer wanted to integrate novel services and adapt retail processes to better serve and meet the needs of the store‘s rural customers closer to their homes. Customers living in rural areas were known not to have access to the retailer‘s online store‘s larger selection. In the development of the novel service concept the utilization of Internet possibilities and the importance of sales persons guiding and socializing alongside the customers at the physical store were also emphasized [44]. Adoption of both online and physical channels, to sell simultaneously through multiple marketing channels, is referred to as multichannel retailing [39]. Today, in an ever digitizing world the line between channels is fading as the different channels are no longer separate and alternative means for delivering shopping services, but customers increasingly use them as complements to each other, or even simultaneously. Hence, the term multichannel is not enough to describe this phenomenon, and instead the new concept of omnichannel is adopted [40]. Omnichannel is defined as ―an integrated sales experience that melds the advantages of physical stores with the information-rich experience of online shopping‖. The customers connect and use the offered channels as best fits their shopping process, creating their unique combinations of using different complementary and alternative channels. In an omnichannel solution the customer has a possibility to seamlessly move between channels which are designed to support this ―channelhopping‖. Case study A was conducted in the context of developing and piloting a novel omnichannel service concept for a Finnish retail chain (described in more detail in [45]). A starting point for the new service was a need to provide a wider selection of goods for the customers of a small, distant rural store. The store is owned by a large national co-operative retail chain. The service concept was based on the idea of providing customers with the selection available in large stores by integrating an e-commerce solution within the service of a rural store. This was practically done by integrating the service provider‘s digital web store to the service processes of the small brick-and-mortar store. Burke [46] suggests that retailers who want to web-enable their store should optimize the interface to the in-store environment instead of just providing web access. Thus, one of the driving design principles of our case study was to achieve a seamless retail experience by a fusion of web and physical retail channels. The novelty of the service concept was in how it was integrated to the service processes of a physical store, i.e., how the different channels were used together to create a retail experience that was as seamless as possible. Payne and Frow [41] examined how multichannel integration affects customer relationship management and stated that it is essential to integrate channels to create positive customer experiences. They pointed out how a seamless and consistent customer experience creates trust and leads to stronger customer relationships as long as the experience occurs both within channels and between them. Technology-savvy consumers expect pre-sales information, during-sales services and after-sales support through a channel customized to their convenience [42]. A co-design process was used in the service design. The build-and-evaluate design cycle involved a small group of researchers and the employees of the retail company. The researchers were active actors in the design process, participating in the service concept design and facilitating co-design activities. Technical experts of the retail 84 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org organization were involved in specification of how the developed solution would best integrate with the existing infrastructures of the organization, and how the new solutions related to the strategic development agenda of other related omnichannel solutions. Retail experts were involved in designing the customer journey, tasks of the staff, the service solution‘s visual and content design, and internal and external communication required by the service. screen (located on the wall above the terminal) that advertised the new retail service concept and directed the customers in its use. 3.1.1. Research Approach of Case Study A The focus of the research was on more closely investigating and analyzing the customer and personnel service experience and deriving design implications from the gained information for developing and improving the service concept further. The user experience data collection methods and the number of stakeholders for each method are listed in Table 1. The pilot study was conducted in a small rural store that was part of the service provider‘s retail chain, located in the city of Kolari (www.kolari.fi) in northern Finland, with a population of 3,836. The customers visiting the physical store could access the selection of goods otherwise not available through a web store interface. The study was launched with a goal of eventually scaling up the digital retail service concept to other small rural stores of the service provider. The retail service included a touch screen customer terminal located inside the physical store (see Figure 3). The research study was focused on the two main user groups: store customers and personnel. Altogether 35 store customers were interviewed, and of these 10 also experimented with the service hands-on by going through the controlled usability testing. The ages of the study participants among the customers varied from 21 years to 73 years. Altogether six members of the store personnel participated in the interviews. Table 1. Summary of the data collection methods and number of participants for each method. Data collection method Number of participants Interviews with store customers 35 store customers Usability testing 10 store customers Paper questionnaires 10 returned questionnaires Group interviews with store personnel 6 members of store personnel Phone calls 1 store superior Automatic behaviour tracking ~484 service users A set of complementary research methods were used to monitor and analyze the retail experience. The interviews were utilized as a primary research method, accompanied by in-situ observation at the store and a questionnaire delivered to customers. These qualitative research methods were complemented with quantitative data achieved through a customer depth sensor tracking system installed inside the store. Interviews were utilized to research customer and personnel attitudes and expectations towards the novel service concept, motivations for the service adoption and usage, their service experiences, and ideas for service improvement. Two types of structured interviews were done with the customers: a) General interview directed for all store customers, and b) interview focusing on the usability aspects of the service (done in the context of the usability testing). Usability testing, accompanied with observations, was conducted to gain insights into the ways customers used the service. Fig. 3 The digital retail service inside the store. The customers could use the terminal for browsing, comparing and ordering goods from the retail provider‘s web store selections. The two web stores accessible through the customer terminal were already existing and available for any customers through the Internet connection. In addition, the retailer piloted the marketing and selling of their own campaign products through a new web store interface available on the customer terminal. The customers could decide whether they wanted their product order delivered to a store (the delivery was then free of charge) or directly to their home. After placing the order, the customer paid for the order at a cash register at the store alongside their other purchases. The customer terminal was also accompanied by a large information Paper questionnaires were distributed for the customers who had ordered goods through the service, with a focus on gathering data of their experiences with the service ordering process. Also a people tracking system based on 85 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org one tablet device). Consumers were able to freely comment on their experience and they were also interviewed after testing the novel service prototype. depth sensor was used to automatically observe the customers. The special focus of the people-tracking was to better understand the in-store customer behavior, and to collect data in more detail of the number of customers using the service through the customer terminal, and of the duration and timing of the service use. 3.2 Case Study B In Case B, the retailer‘s goal was to improve customer service in the consumer goods trades by implementing novel digital service points in the stores. Generally, using these displays customers were able to browse the selection of consumer goods and search detailed information about the products. On displays customers were also able to see advertisements and campaign products available at the store. Customer displays help consumers in making purchase decisions by providing guides and selection assistant. In addition to that, customers can get help to find certain products from the bigger store by utilizing a map service. It has also been planned that customers could use the displays to find a wider selection of consumer goods from the online shop and place the online order in the store. Fig. 4 Test setup in the study. 4. Results and Findings from the Case Studies In this chapter the main results and findings of the case studies are presented in detail for introducing user involvement in the development process. This case study aimed to understand consumer attitudes towards digital service points in Prisma hypermarkets. The research was divided into three tasks: 4.1 Results of Case Study A The findings from Case Study A are analyzed from the viewpoint of two end-user groups, namely the rural store customers and personnel. 1. Digital service points as a service concept 2. Type and location of the digital service point in the store 3. Online shopping in the store. 4.1.1 Store Customers Altogether, 35 customers of the store were asked about their attitudes, expectations, and experiences related to the novel retail service concept. In the study, customers were able to test the first version of the novel user interface to be used in digital service points in stores and compare different screens. The goal was to gather information about customer experience, their expectations and needs, and also ideas of how to develop the user interface further. A test setup of the study is presented in Figure 4. The novel user interface was tested with the big touch screen (on right). The other touch screens were used to test with the web store content just to get an idea about the usability of the screen. Interviews and paper questionnaires. When asked whether or not the customers were likely to use the novel retail service on a scale of 1-5 (where 1 = not likely to use, 5 = likely to use), the average was 2.6, resulting in 16 interviewees responding not likely to use the service and 19 interviewees responding likely to use the service. 3.2.1 Research Approach of Case Study B The work was carried out in the laboratory environment, not in the real hypermarket. Consumers were invited to participate in a personal interview where their attitudes towards customer displays were clarified. The interviews were divided into two phases. First, the background information and purchase behavior was discussed and the novel digital service concept was presented to the customers. In the second phase they were able to test the proof of concept version of the user interface and compare different types of devices (two bigger touch screens and Regarding those 16 customers stating not likely to use the novel retail service, the age distribution was large, as this customer group consisted of persons aged between 21 and 73 years, the average age being 44 years. The gender distribution was very even; 10 men vs. 9 women (some respondents comprised of couples who answered the researchers‘ questions together as one household). Except for one person, all the interviewees said they visited quite regularly the nearest (over 150 kilometers) bigger cities for shopping purposes. Of the 16 respondents 13 had either no or only little experience with online shopping. This 86 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Usability testing. A total of ten store customers participated in the usability testing. The customers were directed to go through a set of predetermined tasks with the retail service interface, and they were asked to ―think aloud‖ and give any comments, feedback and thoughts that came to their mind during the interaction with the service. Their task performance was observed by the researchers and notes were taken during the customer‘s experimentation with the service. The tasks included 1) browsing the product selections available through the web stores, 2) looking for more detailed product information, and 3) ordering a product from two different web stores. customer group gave the following reasons for not being so eager to adopt the novel retail service in use (direct quotes translated from Finnish): “I do not need this kind of a service.” “Everyone has an Internet connection at home. It is easier to order [products] from home.” “Might be good for someone else…” On the other hand, 19 responders stated that they were likely to use the retail service in the future. Also in this customer group the gender distribution was very even, as the responders consisted of 10 men vs. 11 women. The age distribution was respectively diverse, from 29 to 72 years, the average age being 51 years. In addition, everyone regularly made shopping journeys to the closest bigger cities. In this customer group, 11 respondents had some experience with online shopping, with six respondents stating they often ordered products online. These customers justified their interest towards the novel retail service in the following ways (direct quotes translated from Finnish): The biggest difficulty the customers encountered was related to the touch-based interaction with the service terminal. The terminal‘s touch screen appeared not to be sensitive enough, resulting in six out of ten customers experiencing difficulties in interacting with the touch screen. In addition, it was not immediately clear for the customers that the terminal indeed was a touch screen, as six customers hesitated at first and asked aloud whether the terminal had a touch screen: “Do I need to touch this? / Should I touch this?” “Everything [new services] that comes need to be utilized so that the services also stay here [in Kolari].” “We do not have much [product] selections here.” “Really good… No need to visit [bigger cities] if we do not have other businesses/chores there.” “Sounds quite nice… If there would be some product offers.” “If there [in the digital retail service] would be some specific product that I would need, then I could use this.” However, interestingly four customers out of ten changed their initial answer regarding their willingness to use the service (asked before actually experimenting with the service UI) in a more positive direction after having a hands-on experience with the service. Thus, after usability testing, the average raised a bit from the initial 2.6 to 2.7 (on a scale of 1-5). None of the customers participating in the usability testing changed their response in a negative direction. Other valuable usability findings included observation on the font size on the service UI, insufficient service feedback to the customer, and unclear customer journey path. To conclude, age or gender did not seem to have an effect on the store customers‘ willingness to use the retail service. Neither did the shopping journeys to bigger cities influence the willingness for service adoption, as most of the customers made these shopping journeys regularly. However, previous experience with online shopping appeared to have a direct effect on the customers‘ willingness to use the retail service. If the customer did not have, or had only little previous experience with ordering products from web stores, the person in question often also responded not likely to adopt the retail service into use. However, if the customer was experienced with online shopping, they had a more positive attitude and greater willingness to use the novel retail service. Automatic tracking of store customers’ behaviors. A depth sensor-based system was used for detecting and tracking objects (in this case people) in the scene, i.e., inside the physical store. Depth sensors are unobtrusive, and as they do not provide actual photographic information, any potential privacy issues can be more easily handled. The sensor was positioned so that it could observe the customer traffic at the store‘s entrance hall where the service terminal was positioned. Sensor implementation is described in more detail in [47]. Paper questionnaires were distributed to the customers who had ordered products through the retail service (either at home or through the store‘s customer terminal), with the goal of researching customers‘ experiences with the ordering process. These customers identified the most positive aspects of the service as the following: 1) wider product selections, 2) unhurried [order process], 3) easy to compare the products and their prices, 4) fast delivery, and 5) free delivery. The purpose of the implementation of depth sensor tracking was to better understand the in-store customer behavior, and to gather in more detail data of 1) the number of customers using the service terminal, and 2) the duration of the service use. The data was recorded during a total of 64 days. Most of those days contain tracking information from all the hours the store was open. Some 87 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org In addition, the following comments illustrate the general thoughts of the store personnel and expectations regarding the service: hours are missing due to the instability of the peopletracking software. From the recorded data all those store customers that came to the near-range of the service set-up were analyzed. The real-world position of the customers using the service terminal was mapped to the peopletracker coordinates and all the customers that had come into a 30 cm radius of the user position and stayed still more than three seconds were accepted. The radius from the user position was kept relatively small in order to minimize the distortion of data resulting from confusing the users of the slot machine as service terminal users. “This is [indeed a useful service], since we have these long distances [to bigger cities]. Now a customer can buy the washing machine from us.” “Always the adding of more services should be a positive thing.” “More services also always mean more customers.” “When we get our own routines and set-up for this, I’m certain this will succeed!” “…Should have distribution of [personnel‘s] work with this.” The results show that most of the users used the service for a relatively short time. On average 0.54 store customers per hour used the service terminal. It is reasonable to assume that, most likely, a proper usage of the service system would take more than 120 seconds. The shorter the usage period, the less serious or determined the user session has been. Average usage period was 58.4 seconds. Thus, the service usage appeared as quite short-term, indicating that in most cases the service usage was not so ―goal-directed‖, but more like sessions where store customers briefly familiarized themselves with the novel service. During the hours the store was open, from 7am to 9pm, there were on average 7.56 service users/day. For the week, Saturday and Sunday attracted the most service users and the times of most service users were at 1-2pm and 6-7pm. During the first two months of the case study, inquiry calls were made every two weeks to the store superior in order to keep records and obtain information regarding the progress of the service adoption at the store, in addition to possible encountered problems from the viewpoint of both the customers and the personnel. In general, the novel retail service appeared to have been quickly wellintegrated into the personnel‘s work processes. 4.2 Results of Case Study B The target group of the Case Study B included a workingage population. Together 17 people were interviewed (8 women and 9 men). Age distribution varied between 27 and 63 years. Most of the interviewees (88%) lived in the Helsinki metropolitan area. Over half of the interviewees (62%) commonly used the retailer‘s stores to buy daily consumer goods. The most remarkable factor affecting selection of the store was location. Also, selection of goods, quality of the products, price level, bonus system and other services besides the store location were important criteria for consumer choice of which store to go to. 4.1.2. Store Personnel The goal of the group interviews was to investigate store personnel attitudes and expectations towards the novel service concept, and ideas for service improvement and further development. In addition, the store superior was contacted every other week with a phone call for the purpose of enquiring about the in-store service experiences, both from the viewpoint of the store customers and personnel. Consumers are mainly confident with the selection of goods in retailer‘s stores. According to the customers, it is usually easy to find the different products in smaller and familiar stores. In unfamiliar bigger hypermarkets it is sometimes a real challenge. If some product is not available in the store, the customer usually goes to some other store to buy it. Most of the interviewees (71%) also shop online, an average of 1-2 times in a month, and they usually buy clothes and electronics. Online shopping is liked mainly because of cheaper prices, wider selection of consumer goods and it is easy and fast. Group interviews and phone calls. Two group interviews with six members of the store personnel were carried out at the same time as the personnel were introduced and familiarized with the service concept, alongside their new service-related work tasks. In general, the attitudes of the store personnel towards the novel service appeared as enthusiastic and positive. Naturally, the novel service also invoked some doubts, mostly related to its employing effect on the personnel, the clearness and learnability of the order processes, and formation of the new routines related to the service adoption that would also streamline their new work duties, and thus ease their work load. Generally, customers (88%) liked the idea of novel digital service points in the Prisma stores. They felt that the customer displays sped up getting the useful information and made shopping in the stores more effective. According to the interviewees, the most important services were the map service and product information. Especially in bigger hypermarkets, and if the customers are not familiar with 88 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org the store, it is sometimes challenging to find certain products. The map service could include additional information about the location of the department and the shelf where the product can be found. In the hypermarkets there usually are limited possibilities to offer detailed information about the products. With this novel digital service customers are willing to get more information about the products and compare them. 5. Conclusions Today the Internet and digital technologies are becoming more and more integrated across all sectors of our economy and society. Digitalization is everywhere; it is changing the world and our everyday lives. Digital services provide new services or enhanced services to customers and end users. In a DIGILE Digital Services program, 85 Finnish partners innovated and developed novel digital services in 2012-2015 by recognizing the need of enablers in their context. Work was conducted in a true partnership model, in close co-operation with research organizations and companies. During the whole program, ecosystem thinking had a big role in innovating and developing the solutions. The program exceeded the goals by achieving 27 highlighted new services and 18 features. In addition, three new companies were established as a result of ecosystem thinking and companies shared and innovated together new or enhanced digital services. A proof of concept version of the novel user interface received positive feedback; customers thought it was clear, simple and easy to use. They also felt that it was something new and different, compared to traditional web sites. It was pointed out that there is too much content e.g., in Prisma´s web store to be flipped through in the hypermarket. It is important to keep the content and layout of the novel user interface simple. People are more willing to do online shopping at home. Online shopping in the store was still not totally refused, and interviewees found several circumstances when they could utilize it. For example, it could be easy to do online shopping at the same time with other shopping in Prisma stores. If some certain product is no longer available in the store, customers could buy it online in the store, especially the sale products. In many cases in the DS program the role of consumers and stakeholders was remarkable in the development process. Narratives, illustrations and prototypes enhanced the co-development of new solutions from ideas through trials and evaluations to working prototypes. There is a wide scale of tools, methods and knowledge available for demonstrating ideas and opportunities enabled by emerging technologies, and for facilitating co-innovation processes. In this program, novel game-like tools were developed to easily involve different groups of people in the development process. The tools support efficient and agile development and evaluation for identifying viable concepts in collaboration between experts and users. According to the customers there should be several digital service points in Prisma stores, customers are not willing to queue up for their own turn. The service points should be located next to the entrance and also in the departments, next to the consumer goods. The service point should be a peaceful place where they have enough privacy to concentrate on finding information and shopping. Still, there should be something interesting on the screen, something that attracts the customers. The youngest interviewees commented that they would like to go to test the new device and find out what it is, whereas the eldest interviewees said that they would like to know beforehand what they could get from the new service. The screen has to be big enough and good quality. Interviewees thought that the touch screen was modern. Using a tablet as a screen in a digital service point was seen to be too small. In this paper, two retail case studies were presented in detail. Case Study A was conducted in the context of developing and piloting a novel omnichannel service concept in distant rural store. Case Study B concentrated on novel digital service points in hypermarkets. The need for these kinds of novel digital services have different starting points; in the city of Kolari the selection of goods in the local store is limited and the distance to bigger cities and stores is long. In the Helsinki area, the selection of stores and goods is huge and people are also more experienced in shopping online. Still, in both cases, people expect more quality customer service, e.g., in terms of value added shopping experience, easier shopping and wider selection of goods. In both case studies customers stated they were likely to use the novel digital retail services in the future. The behavior of the consumer has changed due to digitalization and this change must be taken into consideration when developing services for the customers. In addition, the retailer got some new ideas for developing customer service in the stores. For example, some of the interviewees suggested a mobile application for customer service and map service, and it could also be used as a news channel. Customers could also create personalized shopping lists with it. Authentication to the digital service point could be executed by fidelity cards in order to receive personalized news and advertisements and to accelerate the service. 89 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org co-develop the retail services. It is noticed that active user involvement in the early stage of a development process increases the quality of the novel service, and user involvement leads to better user acceptance and commitment. Integrating novel digitally-enabled retail services with a physical store requires innovative thinking from retailers. Customers are interested in having these types of novel digital services in the stores; they feel them to be modern and forward-looking options. Most of the customers see that the digital service points make shopping more effective and they expect that they will get useful information faster compared to current situation in the hypermarkets. As introduced in this paper, user involvement and codesign have a central and very important role when developing novel digital services for customers. In fact, feedback and opinions of end users can significantly improve or change the final results. The DS program facilitated the development of novel digital services by providing an ecosystem where companies could share and pilot their innovations. This kind of ecosystem thinking was seen in a very useful and productive manner. These retail-related case studies were implemented in order to better understand the challenges and opportunities in this domain. Based on these studies the most important issues for retailers to take into account when implementing digital services in the stores are: Acknowledgments Keep it simple. Keeping the layout and user interface clear and easy makes it possible to serve all the user groups digitally. This work was supported by Tekes – the Finnish Funding Agency for Innovation (http://www.tekes.fi/en) and DIGILE. We also want to thank all the tens of participants we have worked with in this program. Central location. Digital service points should be situated in noticeable positions in the stores. Customers do not want to search for the service points or queue up for using the service. Enlarging and clarifying the instructional and information texts is part of this issue. Also, elements in the graphical user interface must be considered carefully to arouse customer interest when they are passing by. Adding more privacy. Despite the central location privacy issues have to be taken into consideration when implementing the digital service point in the store. The service points should offer an undisturbed place for searching information and shopping. High quality screens. Customers are nowadays experienced with using different kinds of screens. A touch screen was felt to be modern. The screens have to be high quality to ensure the smoothness of interaction between the customer and the service terminal user interface. Going mobile. 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ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [36] Maestro (2012). ‖Kaupan alan trendikartoitus 2013: Hyvästit itsepalvelulle – älykauppa tuo asiakaspalvelun takaisin.‖ Available: http://www.epressi.com/tiedotteet/mainonta/kaupan-alantrendikartoitus-2013-hyvastit-itsepalvelulle-alykauppa-tuoasiakaspalvelun-takaisin.html?p328=2 [20.2.2014]. [37] Frost & Sullivan (2012). ―Bricks and Clicks: The Next Generation of Retailing: Impact of Connectivity and Convergence on the Retail Sector.‖ Eds. Singh, S., Amarnath, A. & Vidyasekar, A. [38] PSFK. (2012). ―The Future of Retail.‖ New York, NY, USA: PSFK Labs. [39] Turban, E., King, D., Lee, J., Liang, T-P. & Turban, D.C. (2010). ―Electronic commerce: A managerial perspective.‖ Upper Saddle River, NJ: USA Prentice Hall Press. [40] Rigby, D. (2011). ―The Future of Shopping.‖ New York, NY, USA: Harvard Business Review. December 2011. [41] Payne, A. & Frow, P. 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(2014). ―Enriching Everyday Experience with a Digital Service: Case Study in Rural Retail Store.‖ 27th Bled eConference, June 1-5, Bled, Slovenia, pp. 1-16. [46] Burke, R.R. (2002). ―Technology and the customer interface: what consumers want in the physical and virtual store.‖ Academy of Marketing Science, 30(4), pp. 411-432. DOI: 10.1177/009207002236914. [47] Mäkelä, S-M., Sarjanoja, E-M., Keränen, T., Järvinen, S., Pentikäinen, V. & Korkalo, O. (2013). ‖Treasure Hunt with Intelligent Luminaires.‖ In the International Conference on Making Sense of Converging Media (AcademicMindTrek '13), October 01-04 (pp. 269-272). New York, NY, USA: ACM Press. M.Sc. Kaisa Vehmas received her M.Sc. in Graphic Arts Technology from Helsinki University of Technology in 2003. She is currently working as a Senior Scientist in the Digital services in context team at VTT Technical Research Centre of Finland Ltd. Since 2002 she has worked at VTT and at KCL (2007-2009). Her background is in printing and media research focusing nowadays on user centric studies dealing with participatory design, user experience and customer understanding especially in the area of digital service development. Dr. Mari Ervasti received her M.Sc. in Information Networks from the University of Oulu in 2007 and her PhD in Human-Centered Technology from Tampere University of Technology in 2012. She is currently working as a Research Scientist in the Digital services in context team at VTT Technical Research Centre of Finland Ltd. She has worked at VTT since 2007. Over the years, she has authored over 30 publications. In 2014 she got an Outstanding Paper Award in Bled eConference. Her research interests include user experience, user-centered design and human computer interaction. Dr. Maarit Tihinen is a Senior Scientist in the Digital services in context team at VTT Technical Research Centre of Finland. She graduated from the department of mathematics from the University of Oulu in 1991. She worked as a teacher (mainly mathematics and computer sciences) at the University of Applied Sciences before coming to VTT in 2000. She completed her Secondary Subject Thesis in 2001 and received her PhD in 2014 in information processing science from the University of Oulu, Finland. Her research interests include measurement and metrics, quality management, global software development practices and digital service development practices. Lic.Sc. Aino Mensonen obtained her Postgraduate Degree in Media Technology in 1999 from Helsinki University of Technology. She is currently working as a Senior Scientist and Project Manager in the Digital services in context team at VTT Technical Research Centre of Finland Ltd. She started her career at broadcasting company MTV Oy by monitoring the TV viewing and has worked as a Research Engineer at KCL before coming to VTT in 2009. At the moment she is involved in several projects including Trusted Cloud services, Collaborative methods an city planning, User experience, and Service concepts and development. 92 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org GIS-based Optimal Route Selection for Oil and Gas Pipelines in Uganda Dan Abudu1 and Meredith Williams2 1 2 Faculty of Engineering and Science, University of Greenwich, Chatham, ME4 4TB, United Kingdom [email protected] Centre for Landscape Ecology and GIS, University of Greenwich, Chatham, ME4 4TB, United Kingdom [email protected] routing. Impacts to animal migration routes, safety of nearby settlements, security of installations and financial cost implications are all important variables considered in optimal pipeline routing. Jankowski [7] noted that pipeline routing has been conventionally carried out using coarse scale paper maps, hand delineation methods and manual overlaying of elevation layers. Although conventional, it emphasises the importance spatial data play in determining where the pipeline is installed. This has also pioneered advancement in spatial-based pipeline planning, routing and maintenance. Abstract The Ugandan government recently committed to development of a local refinery benefiting from recently discovered oil and gas reserves and increasing local demand for energy supply. The project includes a refinery in Hoima district and a 205 kilometre pipeline to a distribution terminal at Buloba, near Kampala city. This study outlines a GIS-based methodology for determining an optimal pipeline route that incorporates Multi Criteria Evaluation and Least Cost Path Analysis. The methodology allowed for an objective evaluation of different cost surfaces for weighting the constraints that determine the optimal route location. Four criteria (Environmental, Construction, Security and Hybrid) were evaluated, used to determine the optimal route and compared with the proposed costing and length specifications targets issued by the Ugandan government. All optimal route alternatives were within 12 kilometres of the target specification. The construction criteria optimal route (205.26 km) formed a baseline route for comparison with other optimal routes. Keywords: GIS, MCE, LCPA, Oil & Gas, pipeline routing. The approaches used in this paper are presented as an improvement and a refinement of previous studies such as those conducted by Anifowose et al. [8] in Niger Delta, Nigeria, Bagli et al. [9] in Rimini, Italy, and Baynard (10) in Venezuela oil belts. This study was the first of its kind in the study area and incorporated both theory and practice in similar settings and model scenarios for testing to support the decision making process. The study understood that evaluation of the best route is a complex multi criteria problem with conflicting objectives that need balancing. Pairwise comparison matrix and Multi Criteria Evaluation (MCE) were used to weight and evaluate different factors necessary for deriving optimal routes, and then Least Cost Path Analysis (LCPA) used to derive alternative paths that are not necessarily of shortest distance but are the most cost effective. 1. Introduction Lake Albertine region in Western Uganda holds large reserves of oil and gas that were discovered in 2006. Tests have been continually carried out to establish their commercial viability and by August 2014, 6.5 billion barrels had been established in reserves [1, 2 & 3]. The Ugandan government plans to satisfy the country’s oil demands through products processed at a local refinery to be built in Kabaale, Hoima district and transported to a distribution terminal in Buloba, 14 kilometres from Kampala capital city [4]. Several options have been proposed on how to transport the processed products from the refinery to the distribution terminal, this study explored one option; constructing a pipeline from Hoima to Kampala [5]. 2. Study Area Uganda is a land locked country located in East Africa (Fig. 1). The refinery and distribution terminal locations define the start and end points respectively for the proposed pipeline route. The refinery is located near the shores of Lake Albert at Kabaale village, Buseruka sub-country in Hoima district, on a piece of land covering an area of 29 square kilometres. This location lies close to the country’s largest oil fields in the Kaiso-Tonya which is 40 kilometres Determination of the optimal route for pipeline placement with the most cost effectiveness and least impact upon natural environment and safety has been noted by Yeo and Yee [6] as a controversial spatial problem in pipeline 93 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org and a hybrid cost surface comprising of all criteria factors. Different cost surfaces for each of the criteria were generated and evaluated to identify the combination of factors for an optimal pipeline route and the route alternatives determined using Least Cost Path Analysis. by road from Hoima town. Kaiso-Tonya is also 260 kilometres by road from Kampala, Uganda’s capital. The approximate coordinates of the refinery are: 1⁰30’0.00”N, 31⁰4’48.00”E. The distribution terminal is located at Buloba town centre approximately 14 kilometres by road, west of Kampala city. The coordinates of Buloba are: 0⁰19’30.00”N, 32⁰27’0.00”E. The geomorphology is characterised by a small sector of flat areas in the northeastern region and rapid changing terrain elsewhere with elevations ranging from 574 to 4,877 metres above sea level. The most recent population census was carried out in 2014 and reported total national population results of 34.9 million covering 7.3 million households with 34.4 million inhabitants [11]. This represented a population increment of 10.7 million people from the 2002 census. Subsistence agriculture is predominantly practiced throughout the country as a major source of livelihood as well as fishing and animal grazing. Temperature ranges between 20 - 30 ºC with annual rainfall between 1,000 and 1,800 mm. 3.1 Data Achieving the study objectives required the use of both spatial and non-spatial data (Table 1). Data were obtained from government departments in Uganda and supplemented with other publicly available data. The choice of input factors was determined by the availability of data, their spatial dimensions and computational capacity. The study noted that there are many factors that can influence the routing of an oil and gas pipeline. However, only factors for which data were available were examined. Spatial consistency was attained by projecting all data to Universal Transverse Mercator (UTM) projection, Zone 36N for localised projection accuracy and a spatial resolution of 30 m maintained during data processing. Table 1: Data used for designing the cost surface layers Data type Wellbores & Borehole data Rainfall & Evapotranspiration Soil map Topography Geology Land cover Soil Population Wetlands Streams (Minor & Major) Urban centres Protected sites Boundary, source & destination Linear features (Roads, Rail, Utility lines) Construction costs Fig. 1: Location Map of Uganda, East Africa 3. Methodology The methodology utilised a GIS to prepare, weight, and evaluate environmental, construction and security factors used in the optimal pipeline routing. Estimates for local construction costs for specific activities such as the actual costs of ground layout of pipes, building support structures in areas requiring above ground installations, and maintenance costs were beyond the scope of the available data. However, cost estimates averaged from published values for similar projects in the USA and China [12, 13 & 14] were used to estimate the total construction costs of the optimal route. Multi Criteria Evaluation of pairwise comparisons were used to calculate and obtain the relative importance of each of the three major criteria cost surfaces Format Scale Date Table & Points 1:60,000 2008 Table & Raster 30 metre Raster Raster Raster Raster Raster Raster & Table Raster 30 metre 30 metre 30 metre 30 metre 30 metre 30 metre 30 metre 19902009 1970 2009 2011 2010 2008 2014 2010 Raster 30 metre 2007 Vector Vector 1:60,000 1:60,000 2013 2011 Vector 1:60,000 2014 Vector 1:60,000 2009 Table 1:60,000 2009 3.2 Routing Criteria Pipeline route planning and selection is usually a complex task involving simultaneous consideration of more than one criterion. Criteria may take the form of a factor or a constraint. A factor enhances or detracts from the suitability of a specific alternative for the activity under 94 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org consideration. For instance, routing a pipeline within close distance to roads is considered more suitable compared to routing it far away from the road. In this case, distance from the road constitute a factor criterion. Constraints on the other hand serve to limit the alternatives under consideration, for instance protected sites and large water bodies are not preferred in any way for pipelines to be routed through them. Environmental criteria The environmental criteria were aimed at assessing the risks and impacts upon the environmental features found in potential corridors of the pipeline route. Two objectives were addressed, i.e. minimising the risks of ground water contamination (GWP) and maintaining least degrading effect on the environment such as the effects on land cover, land uses, habitats and sensitive areas (DEE). A GIS-based DRASTIC Model (Fig. 3) was used to assess areas of ground water vulnerability while a weighted overlay model was used in determining areas with least degrading environmental effects. Routing a pipeline is therefore, more complex than simply laying pipes from the source refinery to the final destination. Natural and manmade barriers along possible routes have to be considered as well as the influences these barriers have on the pipeline after installation. Accurate determination of the impact of these factors and constraints on pipeline routes is usually a time-consuming task requiring a skilled and dedicated approach [15]. This study employed a criteria-based approach in order to consider the different barriers and factors required to perform optimal pipeline route selection. Datasets were selected and processed into friction surfaces and grouped into three separate strands of criteria for analysis. Fig. 2 shows the implementation methodology and the grouping of the criteria (environmental, engineering and security). Fig. 3: DRASTIC Model Construction criteria Construction criteria considered factors and constraints that accounted for the costs of laying oil and gas pipelines through the route. Two objectives were addressed; maximising the use of existing rights of way around linear features such as roads and utility lines (ROW), and maintaining routing within areas of low terrain costs (HTC). Although, the criteria aimed at minimising costs as much as possible, maintenance of high levels of pipeline integrity was not compromised. Security criteria Oil and gas pipeline infrastructures have been vandalised and destroyed in unstable political and socio-economic environments [16]. Political changes in Uganda have often been violent, involved military takeover leading to destruction of infrastructures and resources. Therefore, the security of the proposed pipeline has always been a concern. Also, the proposed pipeline is projected to be laid Fig. 2: Flow diagram of the implementation methodology 95 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org summary of the normalised weights derived from expert opinion is shown in Table 10. above ground traversing through different land cover types, administrative boundaries and cultural groupings comprising the study area. It is therefore, imperative that security is kept at high importance in consideration of the pipeline route. Two objectives were addressed by the security criteria: Table 2: DRASTIC Model Description and assigned Standard Weights S/n 1 Factor Description Weights Depth to Depth from ground surface to water 5 water table table. Represents the amount of water per unit area of land that penetrates the 4 Net Recharge ground surface and reaches the water table. Refers to the potential area for water Aquifer logging, the contaminant attenuation 3 of the aquifer inversely relates to the media amount and sorting of the fine grains Refers to the uppermost weathered 2 Soil media area of the ground. Refers to the slope of the land Topography 1 surface. It is the ground portion between the Impact of aquifer and soil cover in which pores 5 vadose zone or joints are unsaturated. Indicates the ability of the aquifer to transmit water and thereby Hydraulic determining the rate of flow of 3 conductivity contaminant material within the ground water system. First, facilitation of quick access to the pipeline facility (QCK) and secondly, protection of existing and planned infrastructures around the pipeline route (PRT). This is in line with the observation that pipeline infrastructure poses a high security risk to the environment and communities, and is of international concern [17]. Pipeline infrastructures suffer from illegal activities involving siphoning, destruction and sabotage, disrupting the supply of oil products. Similar studies such as the Baku-TblilsiCeyhan (BTC) pipeline [18] and the Niger Delta pipeline [19] reported significant effects of pipeline infrastructure vandalism and the need for proper security planning to counter such activities during pipeline route planning. It is also important that oil and gas pipelines are regularly monitored and maintained against wear and tear effects on the pipe materials, pressure, and blockages inside the pipeline. Routing in locations with ease of access for maintenance, emergency response and protection against vandalism were therefore addressed. Source: [21] 3.3 Weighting Criteria 3.4 Estimating the construction costs The weighting criteria used were based on weights derived from literature review and expert opinions. Questionnaires were used to collate responses from experts as well as standard weights (Table 2) sourced from literature that were incorporated to weigh and derive the optimal routes. The construction costs for each pipeline alternative were estimated using the economic model proposed by Massachusetts Institute of Technology (MIT), Laboratory for Energy and the Environment (LEE) (MIT-LEE) [13]. MIT applied the model to estimate the annual construction cost for a Carbon Dioxide (CO2) pipeline. Data used were based on Natural Gas pipelines due to the relative ease of availability. The cost data were used to estimate the pipeline construction costs. Although, the rate of flow and pipeline thickness of these two types of pipelines (Natural Gas and oil) may differ, the land construction costs does not differ much. The costs of acquiring pipeline materials such as pipes, pump stations, diversions and support structures were not included in the analysis. Equation 1 illustrates the formula used to estimate the total construction cost (TCC) over the operating life of the pipeline in British Pounds Sterling (BPD): 2 3 4 5 6 7 Values were assigned to each criterion based on their degree of importance in the containing criteria. For example, gentle slopes provide solid foundations for laying pipelines so it received higher weight (lower friction value) in the construction criteria whereas steep slopes require levelling and/or support posts to raise the pipeline above ground hence it received low weight (higher friction value). Based on linguistic measures developed by Saaty [20], weights were assigned on a scale of 1 to 9 semantic differentials scoring to give relative rating of two criteria where 9 is highest and 1 is lowest. The scale of differential scoring presumes that the row criterion is of equal or greater importance than the column criterion. The reciprocal values (1/3, 1/5, 1/7, or 1/9) were used where the row criterion is less important than the column criterion. A decision matrix was then constructed using Saaty’s scale and factor attributes were compared pairwise in terms of importance of each criterion to that of the next level. A TCC = LCC × CCF + OMC (1) Where, LCC is the Land construction cost in BPD, CCF is the Capital Charge Factor, OMC is the annual operation & management costs in BPD 96 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org CCF values were defaulted to 0.15 and the OMC estimated at BPD 5,208.83 per kilometre per year irrespective of the pipeline diameter [14]. LCC were obtained from two correlation equations which assume a linear relationship between LCC and distance and length of the pipeline. Equations 2 and 3 illustrate the formula used to obtain LCC for the MIT and Carnegie Mellon University (CMU) correlation models respectively. 1. regional differences in pipeline construction costs by using regional dummy variables. The two correlations provided comparative results for the study area. LCC = β × Dx × (L × 0.62137)y × z × i Where, β = BPD 27187.55 D = pipeline diameter in inches and x = 1.035 L = pipeline length in kilometres and y = 0.853 z = regional weights = 1 (since regional weights are constant) i is optional. It is the cost fluctuation index due to increase in inflation and costs in a given year (Table 4). The study used running average index for year 2007. In the MIT correlation, it is assumed that the pipeline’s LCC has a linear correlation with pipeline’s diameter and length LCC = α × D × (L × 0.62137) × i (2) Where, α = BPD 21,913.81 (variable value specific to the user) per inch per kilometre D is the pipeline diameter in inches L is the least-cost pipeline route length in Kilometres i is optional. It is the cost fluctuation index due to increase in inflation and costs in a given year. The study used the running average for year 2007 (Table 3). 4. Results and Discussion This section presents the results of the various analyses carried out in the study. Maps, Figures and Tables make up the content together with detailed descriptions and discussion of the results shown. Table 3: MIT Correlation Price Index Year 2000 2001 2002 2003 2004 2005 2006 2007 Index (i) 1.51 1.20 1.74 2.00 2.30 2.31 2.30 3.53 (3) 4.1 Weights used in the study Running Average 1.47 1.48 1.65 2.01 2.20 2.30 2.71 2.92 The study employed both primary and secondary data. Primary data were obtained from a sample of experts in the fields of oil and gas, environment, plus cultural and political leaders. Questionnaires were used to collect expert opinions from 20 respondents from each of the three fields. Fig. 4 shows the category of respondents and the percentage responses obtained for each of the categories. Table 10 shows the comparative responses normalised in percentage. Source; [13] Table 4: CMU Correlation Price Index Year 2000 2001 Index (i) 1.09 0.99 Running Average 1.05 1.08 2002 1.17 1.16 2003 2004 2005 1.33 1.56 1.52 1.35 1.47 1.57 2006 1.68 1.59 2007 2.46 2.07 Source; [13] 2. Fig. 4: Respondents collated from questionnaires The CMU correlation model is similar to the MIT model. However, it is more recent and departs from the linearity restriction in the MIT correlation and allows for a double-log (nonlinear) relationship between pipeline LCC and pipeline diameter and length. In addition, the CMU correlation model takes into account 4.2 Environment cost surface An environmental cost surface (Fig.5C) was obtained by applying equal weighting on two objective-based cost surfaces; that is maintaining least degrading effect on the 97 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org 4.6 Optimal route environment (DEE) and protection of ground water from contamination arising from pipeline related activities (GWP), represented in Fig. 5 (A) and (B) respectively. Additionally, studies by Secunda et al. [22] revealed that assuming constant values for the missing layers in the DRASTIC Model produced the same results as when all seven layers were used. This study applied constant values to the three cost layers (Net Recharge, Impact of vadose and Hydraulic conductivity) based on literature because these layers have values representing a country-wide extent [23]. Table 5 shows the accumulated costs incurred by each route and the total distance traversed by the optimal routes. While the diameter of the actual pipes for the proposed pipeline have yet to be decided, a buffer of 1 kilometre was applied around the optimal routes to generate a strip accounting for the potential right-of-way. Also, there were no routing activities conducted for oil and gas pipeline in the study area prior to this study. The Government’s estimated total distance for the pipeline route determined by a neutral criteria was 205 kilometres [4]. Therefore, this study considered the optimal route with the shortest length as a baseline route for comparisons with other optimal routes. 4.3 Construction cost surface A Construction cost surface (Fig. 6C) was obtained by applying equal weighting on two objective-based cost surfaces; maintaining the use of areas with existing right of way (ROW, Fig. 6A) and minimising areas with high terrain cost (HTC, Fig. 6B). The cost surfaces for both ROW and HTC show that distribution of the costs cover the entire study area. Over 50% of the study area presented very low ROW with a few areas in the West, Central and Eastern parts of the study extent recording high costs indicating areas of urban concentrations, Mount Elgon to the East and protected sites covering the South-Western part of the study area and North-Eastern parts. Similarly, one protected site (licensed sites for oil drilling purposes) and all major streams (lakes and rivers) presented higher costs to the construction criteria. Much of the Central and Northern parts of the country are cheaper. Moderate construction costs are observed around areas covered by protected sites such as national parks, cultural sites, wildlife reserves and sanctuaries. This is so because the importance of these protected sites are evaluated entirely on economic terms (ROW and HTC objectives). Table 5: Costs and lengths of the optimal routes Optimal route alternatives Accumulated cost distance Pipeline length (km) Environmental Construction Security Hybrid 1,529,468.00 1,363,801.75 1,393,417.50 1,255,547.75 213.09 205.26 209.52 215.11 Length difference from the proposed length +8.09 +0.26 +4.52 +10.12 The construction criteria optimal was the shortest route with a length of 205.26 kilometres, a 0.26 kilometre increase over the 205 km estimate proposed by Ugandan government. From Table 5, the environmental, security and hybrid are respectively 8.09, 4.52 and 10.12 kilometres longer than the proposed route. The baseline route also has an accumulated cost cheaper than both security and environmental criteria. However, the hybrid criteria optimal route is 1.95% cheaper than the baseline route. This suggests that the incorporation of multiple constraints and criteria in the optimal route selection minimises the resultant costs associated with routing. 4.4 Security cost surface A security cost surface was obtained from equal weighting of the QCK and PRT cost surfaces. QCK and PRT cost surfaces are the two objective-based cost surfaces for which the security criteria achieved. The results are shown in Fig. 7 (A), (B) and (C) for QCK, PRT and security criteria cost surfaces respectively. In the three maps, costs were represented as continuous surfaces. 4.7 The financial implications of each optimal route Construction cost estimates from Tables 6 and 7 show that construction costs linearly vary with increases in both pipeline diameter and length across the two models. The shorter the route and the narrower the pipeline, the cheaper the construction costs. Fig. 10 shows the graphical representation of the linear relationship between pipeline construction costs and both pipeline diameter and length. 4.5 Hybrid cost surface The final cost surface obtained is the hybrid cost surface where the six cost surfaces (DEE, GWP, ROW, HTC, QCK and PRT) were combined and equally weighted. A continuous surface was generated as shown in Fig. 8 (A). 98 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Table 6: TCC estimates for the optimal routes based on MIT Model Pipeline length (km) Optimal Routes Total construction cost (MIT Model) in millions of BPD Pipeline diameter in inches 8 16 18 24 30 36 Land uses such as roads, urban centres and protected sites were crossed by at least one of the four optimal routes. Linear features (Roads, Rail roads, utility lines) and minor streams were among the most crossed features by the optimal routes. No urban and protected sites were directly crossed by the optimal routes. However, when a spatial buffer of 200m was applied around the urban centres, five urban centres and one protected site were crossed by the optimal routes (Table 8). Of the affected urban centres, four were crossed by security optimal route while hybrid optimal route crossed one urban centre. The location of the refinery is within a 1km buffer around one of the protected sites (Kaiso-Tonya Community Wildlife Management Area). 40 42 Environmental 213.09 10.2 20.3 22.9 30.5 38.1 45.8 50.8 53.4 Construction 205.26 9.8 19.6 22.0 29.4 36.7 44.1 49.0 51.4 Security 209.52 10.0 20.0 22.5 30.0 37.5 45.0 50.0 52.5 Hybrid 215.11 10.3 20.5 23.1 30.8 38.5 46.2 51.3 53.9 Table 7: TCC estimates for the optimal routes based on CMU Model Pipeline Optimal Routes length (km) Total construction cost (CMU Model) in millions of BPD Pipeline diameter in inches 8 16 18 24 30 36 40 42 4.9 Monitoring and maintenance planning along the optimal routes Environmental 213.09 7.0 14.4 16.3 21.9 27.6 33.4 37.2 39.2 Construction 205.26 6.8 14.0 15.8 21.3 26.8 32.3 36.1 37.9 Security 209.52 6.9 14.2 16.1 21.6 27.2 32.9 36.7 38.6 Hybrid 215.11 7.1 14.5 16.4 22.1 27.9 33.7 37.5 39.5 In order to properly monitor and maintain efficient operation of the pipeline, pipeline routes were preferred to be near linear features such as roads, rail roads and utility lines since they provide quick and easy access to the pipeline facility. Also, locations near streams were preferred to allow access using water navigation means. For planning purposes such as installation of monitoring and maintenance facilities such as engineering workshops and security installations, areas with clear line of sight are recommended. The study therefore performed Viewshed analysis [24] on the on topographical data to determine visible areas. Fig. 9 (B) shows the locations visible from each of the four optimal routes as determined from ArcGIS Viewshed Analysis. Although, the Viewshed analysis performed on DEM does not consider the above-ground obstructions from land cover types such as vegetation and buildings, it can be compensated by installing such monitoring facilities at the appropriate height above ground while maintaining the site location. Considering the total construction cost for a 24-inch diameter pipeline, The total construction costs for the Government’s proposed pipeline route is 29.34 million BPD, whereas for security, environmental and hybrid routes are 30.0, 30.5 and 30.8 million BPD respectively using the MIT Model. Also using the CMU Model similar trend in results are shown where the baseline route (the shortest) also doubling as the cheapest route estimated at 21.3 million BPD, followed by security, then environmental and finally hybrid at 21.6, 21.9 and 22.1 million BPD respectively. Therefore, the financial implication of each optimal route shows the construction criteria optimal route as the cheapest and most feasible. The other three optimal routes (security, environmental and hybrid) although longer and more expensive, are all under 1.59 and 2.54 million BPD from the CMU and MIT models’ construction costs estimates. 5. Sensitivity testing of weighting schemes 4.8 Effects of optimal routes on land cover and uses 5.1 The effect of equal weighting and weights obtained from expert opinion on the optimal routes Twelve different land cover types were considered in the study, seven of which (Table 9) were crossed by at least one of the four optimal routes. Woodland, grassland, small-scale farmland, wetlands and degraded tropical high forests all were crossed by the optimal routes. Environmental and hybrid optimal routes were the only routes that crossed Bushland. Also, construction and security optimal routes were the only routes that crossed stocked tropical high forest. Equal weightings were applied to combine criteria objectives and generate criteria cost surfaces as the first stage of analysis. Weights normalised from expert opinions were then used to provide comparative results of the analysis for environmental, construction and security criteria. The hybrid criteria was not affected because nonequal weightings were applied at the objectives evaluation level. The significant result was shown in the 99 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org environmental criteria route where the 25% weight change in the DEE objective resulted in a 7.79% (16.61 km) increase in the overall pipeline length under environmental criteria. This was the highest change in the pipeline length followed by security criteria at (0.44 km) and lastly construction criteria at 0.05 km. Environmental criteria optimal route was also the longest route with a total length at 229.70 km followed by hybrid at 215.11 km, security at 210.18 km and lastly construction criteria at 205.31 km. Although, the environmental route had the longest length, security criteria accumulated the highest cost while construction had the least accumulated cost distances. 5.2 Application of non-equal weighting on criteria to generate hybrid route Table 8: Number of crossings by the optimal routes through buffer zones Features Environmental Construction Security Hybrid Roads 10 12 10 13 Lakes & 0 0 0 0 Rivers Minor 14 9 13 16 Streams Utility 2 2 2 2 Lines Rail roads 0 1 0 0 Urban 0 0 4 1 centres Protected 1 1 1 1 sites Total 27 25 30 33 Figures 5 & 11, shows the location of the hybrid optimal route generated from the application of equal weighting on the three criteria (environmental, construction and security). The route is within 1.51 kilometres south of Hoima town. By applying an un-equal weighting where the environmental criteria accounted for 50% of the total weight, security and construction at 25% each, the route was shifted 12 km further south of Hoima town (Fig. 11). Other urban centres such as Kitoba and Butemba that were initially close to the equal weighted hybrid route (11.83 & 11.96 kms respectively) were also shifted (50 and 20 kms respectively) away from the non-equal weighted route. Table 9: Areal coverage (square metres) of land cover type crossed by each pipeline route Land cover The length of the non-equal weighted hybrid route decreased from 215.11 km to 212.94 km representing a construction cost decrement of 0.3 BPD based on MIT Model for a 24-inch pipeline. Using CMU model, the construction costs decrement is at 0.2 BPD for the same pipeline diameter. Similarly, increasing the security and construction criteria by 50% respectively, while maintaining the environmental criteria weights at 25% in each case resulted in cheaper routes but presented real risk to some urban centres. For instance, the 50% security criteria weighting resulted in the hybrid optimal route crossing the buffer zone of Ntwetwe town while avoiding Bukaya by 0.2 kilometre (Fig. 9C). Although the effect of applying un-equal weighting on the hybrid criteria optimal route had no incremental effect on the total length and costs of the pipeline, the potential effects on other criteria routes are visible. However, generally un-equal weighting had minimal adverse effects upon the environmental, construction and hybrid optimal routes. Environmental Construction Security Hybrid Grassland 2,223,000 386,100 Bushland 270,000 0 0 346,500 Woodland 957,600 1,208,700 600,300 560,700 Small-Scale Farmland 2,219,400 4,383,900 Wetland 27,900 261,000 288,000 76,500 0 52,200 244,800 0 253,800 231,300 15,300 278,100 5,951,700 6,523,200 Tropical high forest (stocked) Tropical high forest (degraded) Total 27,900 2,014,200 4,161,600 3,029,400 5,337,900 6,305,400 Fig. 5: Location of the optimal routes 100 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Table 10: Summary of normalised factor weights used in determination of cost surface layers 1. DEE Objective Factor/ Weight (%) Constraint Urban centres 7.53 Land cover 50.92 Protected sites 26.30 Wetlands 15.25 2. ROW Objective 3. HTC Objective Factor/ Weight Factor/ Weight Constraint (%) Constraint (%) Linear 5.83 Land cover 6.48 features Population 0.55 Soil 38.52 density Protected 24.78 Topography 18.31 sites Cultural 14.38 Linear features 10.88 landmarks Geology 25.18 Environmental Criteria 4. QCK Objective Factor/ Weight Constraint (%) Linear 20.16 features Streams Dense land cover Urban centres Construction Criteria 30.62 8.13 41.08 5. PRT Objective Factor/ Weight Constraint (%) Urban 20.16 centres Protected 30.62 sites Linear 8.13 features Cultural 41.08 landmarks Security Criteria B A C Fig. 6: Cost surface maps showing DEE (A), GWP (B) objectives and combined environmental criteria cost surface (C) C Fig. 7: Cost surface maps showing ROW (A) and HT (B) objectives and combined Construction criteria cost surface (C) 101 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org C Fig. 8: Cost surface map showing the ROW objective (A) and the PRT objective (B) and combined Security criteria cost surface (C) A B B C Fig. 9: Hybrid cost surface map (A), visible locations to optimal routes (B) and all five route alternatives (C) 102 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org 6. Conclusions This paper presented a GIS-based methodology for the identification of an optimal and cost effective route for the oil and gas pipeline as well as taking into consideration the environmental, economic and security concerns associated with oil and gas pipeline routing. The effects on land cover and land uses, ground water contamination, costs of investments, human and wildlife security, and emergency responses to adverse effects such as oil spillage and pipeline leakages were considered in the routing activity. Given that governments and religious affiliations of the people can change any time, factors with long-term effects upon the installation and operation of the oil and gas pipelines were key in the decision making process. While the analyses were successful and objectives achieved, the study noted that community participation in pipeline routing is the most essential component of any complex multi criteria study. Factors such as socio-political, socioeconomic and religious factors for which data are often unavailable or unreliable are recommended to be incorporated in any future studies. Similarly, land prices where compulsory land purchases are required should be conducted to estimate the pre-installation market values of land. Acknowledgments Fig. 10: Construction costs variation The Authors acknowledge the technical and software support obtained from the Faculty of Engineering and Science, University of Greenwich. The authors also thank the various departments of Uganda government, GISTITOS project, Nile Basin Initiative and USGS Earth Explorer Project to name but a few that provided the required data. Finally the lead author’s profound gratitude goes to Tullow Group Scholarship Scheme for providing the scholarship funding. References [1] F.A.K. Kaliisa, “Uganda’s petroleum resources increase to 6.5 billion barrels oil in place”, Department of Petroleum, Uganda, 2014. Available at: http://www.petroleum.go.ug/news/17/Ugandaspetroleum-resources-increase-to-65-billion-barrels-oilin-place. Last accessed: 15/06/2015 [2] C.A. Mwesigye, “Why Uganda is the Best Investment Location in Africa”, State House, Uganda, 2014. Available at: http://www.statehouse.go.ug/search/node/Why%20Uga nda%20is%20the%20Best%20Investment%20Location %20in%20Africa. Last accessed: 15/06/2015 [3] US EIA, “Uganda: Country Analysis Note”, 2014, Available at: http://www.eia.gov/beta/international/country.cfm?iso= UGA. Last accessed: 15/04/2015. Fig. 11: Location of visible areas to the optimal routes 103 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [17] S.k.N. Hippu, S.K. Sanket, and R.A. Dilip, “Pipeline politics—A study of India’s proposed cross border gas projects”, Energy Policy, Vol. 62, 2013, pp. 145 – 156. [18] G. Dietl, “Gas pipelines: politics and possibilities”. In: I.P. Khosla, Ed. “Energy and Diplomacy”, Konark Publishers, New Delhi, 2005, pp.74–90 [19] F. Onuoha, “Poverty, Pipeline Vandalisation/Explosion and Human Security: Integrating Disaster Management into Poverty Reduction in Nigeria”, African Security Review, Vol. 16, No. 2, 2007, pp.94-108, DOI: 10.1080/10246029.2007.9627420. [20] T.L. Saaty, The Analytical Hierarchy Process. New York: Wiley, 1980 [21] R.A.N. Al-Adamat, I.D.L. Foster, and S.N.J. Baban, “Groundwater vulnerability and risk mapping for the Basaltic aquifer of the Azraq basin of Jordan using GIS, Remote sensing and DRASTIC”, Applied Geography, Vol. 23, 2003, pp. 303–324. [22] S. Secunda, M.L., Collin, A.J. Melloul, “Groundwater vulnerability assessment using a composite model combining DRASTIC with extensive agricultural land use in Israel’s Sharon region”, Journal of Environmental Management, Vol. 54, 1998, pp. 39 – 57. [23] MWE, “WATER SUPPLY ATLAS 2010”, 2012, Available at: http://www.mwe.go.ug/index.php?option=com_docma n&task=cat_view&gid=12&Itemid=223. Last accessed: 15/02/2015. [24] E.E. Jones, “Using Viewshed Analysis to Explore Settlement Choice: A Case Study of the Onondaga Iroquois”, American Antiquity, Vol. 71, No. 3, 2006, pp. 523-538. [4] PEPD, “Uganda’s Refinery Project Tender Progresses to the Negotiations Phase”, Department of Petroleum, Uganda, 2014. Available at: http://www.petroleum.go.ug/news/13/UgandasRefinery-Project-Tender-Progresses-to-theNegotiations-Phase. Last accessed: 15/06/2015. [5] Business Week, “Oil boss says pipeline quickest option for Uganda”, East African Business Week, 2014. Available at: http://www.busiweek.com/index1.php?Ctp=2&pI=205 2&pLv=3&srI=53&spI=20. Last accessed: 05/11/2014. [6] I. Yeo, and J. Yee, “A proposal for a site location planning model of environmentally friendly urban energy supply plants using an environment and energy geographical information system (E-GIS) database (DB) and an artificial neural network (ANN)”, Applied Energy, Vol. 119, 2014, pp. 99 – 117. [7] P. Jankowski, “Integrating geographical information systems and multiple criteria decision-making methods”, International Journal of Geographical Information Systems, Vol. 9, No. 3, 1995, pp. 251-273. [8] B. Anifowose, D.M. Lawler, V.D. Horst, and L. Chapman, “Attacks on oil transport pipelines in Nigeria: A quantitative exploration and possible explanation of observed patterns”, Applied Geography, Vol. 32, No. 2, 2012, pp. 636 – 651. [9] S. Bagli, D. Geneletti, and F. Orsi, “Routeing of power lines through least-cost path analysis and multicriteria evaluation to minimise environmental impacts”, Environmental Impact Assessment Review, Vol. 31, 2011, pp. 234 – 239. [10] C.W. Baynard, “The landscape infrastructure footprint of oil development: Venezuela’s heavy oil belt”, Ecological Indicators, Vol. 11, 2011, pp.789 – 810. [11] UBOS, “National Population and Housing Census 2014, Provincial Results”, 2014, Available at: http://www.ubos.org/onlinefiles/uploads/ubos/NPHC/ NPHC%202014%20PROVISIONAL%20RESULTS% 20REPORT.pdf. Last accessed: 13/02/2015. [12] B. Bai, X. Li, and Y. Yuan, “A new cost estimate methodology for onshore pipeline transport of CO2 in China”, Energy Procedia, Vol. 37, 2013, pp. 7633 – 7638. [13] CCSTP, “Carbon Management GIS: CO2 Pipeline Transport Cost Estimation. Carbon Capture and Sequestration Technologies Program Massachusetts Institute of Technology”, 2009, Available at: http://sequestration.mit.edu/energylab/uploads/MIT/Tr ansport_June_2009.doc. Last accessed: 02/05/ 2015 [14] G. Heddle, H. Herzog, and M. Klett, “The Economics of CO2 Storage. MIT LFEE 2003-003 RP”, 2003, Available at: http://mitei.mit.edu/system/files/2003-03rp.pdf. Last accessed: 12/05/2014. [15] Oil & Gas, “GIS leads to more efficient route planning”, Oil & Gas Journal, Vol. 91, No. 17, 1993 pp. 81. [16] S. Pandian, “The political economy of trans-Pakistan gas pipeline project: assessing the political and economic risks for India”, Energy Policy, Vol. 33, No. 5, 2005, pp. 659–670. Dan Abudu was awarded a BSc in Computer Science (First Class) by Gulu University, Uganda in 2010 and continued his career in Data Management serving at organisiations such as Joint Clinical Research Centre and Ministry of Finance, Planning and Economic Development in Uganda, and at Kingsway International Christian Centre, UK. He briefly served in Academia as Teaching Assistant (August 2010 – April 2011). Dan has been active in GIS and Remote Sensing research since 2013 with keen interests in GIS applications in Oil and Gas sector. He is a member of the African Association of Remote Sensing of the Environment (AARSE) and was awarded an MSc in GIS with Remote Sensing from the University of Greenwich, UK on the 22nd July 2015. Dr. Meredith Williams is a Senior Lecturer in Remote Sensing and GIS at the Centre for Landscape Ecology & GIS, University of Greenwich, Medway Campus, UK, with over 23 years experience in applied GIS and Remote Sensing. He specialises in the application of Remote Sensing and GIS to the monitoring of vegetation health, land cover change, and fluvial systems. He has supervised a wide range of PhD and MSc projects, including several in collaboration with the oil and gas industry. 104 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Hybrid Trust-Driven Recommendation System for E-commerce Networks Pavan Kumar K. N1, Samhita S Balekai1, Sanjana P Suryavamshi1, Sneha Sriram1, R. Bhakthavathsalam2 1 Department of Information Science and Engineering, Sir M. Visvesvaraya Institute of Technology Bangalore, Karnataka, India 1 1 [email protected], [email protected], [email protected], [email protected] 2 Super computer Education and Research Centre, Indian Institute of Science Bangalore, Karnataka, India 2 [email protected] Abstract In traditional recommendation systems, the challenging issues in adopting similarity-based approaches are sparsity, cold-start users and trustworthiness. We present a new paradigm of recommendation system which can utilize information from social networks including user preferences, item's general acceptance, and influence from friends. A probabilistic model, particularly for e-commerce networks, is developed in this paper to make personalized recommendations from such information. Our analysis reveals that similar friends have a tendency to select the same items and give similar ratings. We propose a trust-driven recommendation method known as HybridTrustWalker. First, a matrix factorization method is utilized to assess the degree of trust between users. Next, an extended random walk algorithm is proposed to obtain recommendation results. Experimental results show that our proposed system improves the prediction accuracy of recommendation systems, remedying the issues inherent in collaborative filtering to lower the user’s search effort by listing items of highest utility. Keywords: Recommendations system, Trust-Driven, Social Network, e-commerce, HybridTrustWalker. 1. Introduction Recommendation systems (RS) (sometimes replacing "system" with a synonym such as platform or engine) are a subclass of information filtering system that seek to predict the 'rating' or 'preference' that user would give to an item. RSs have changed the way people find products, information, and even other people. They study patterns of behaviour to know what someone will prefer from among a collection of things he has never experienced. RSs are primarily directed towards individuals who lack sufficient personal experience or competence to evaluate the potentially overwhelming number of alternative items that a Web site, for example, may offer .A case in point is a book recommendation system that assists users to select a book to read. In the popular Website, Amazon.com, the site employs a RS to personalize the online store for each customer. Since recommendations are usually personalized, different users or user groups receive diverse suggestions. In addition there are also non-personalized recommendations. These are much simpler to generate and are normally featured in magazines or newspapers. Typical examples include the top ten selections of books, CDs etc. While they may be useful and effective in certain situations, these types of non-personalized recommendations are not typically addressed by RS research. 1.1 Recommendation System Functions First, we must distinguish between the roles played by the RS on behalf of the service provider from that of the user of the RS. For instance, a travel recommendation system is typically introduced by a travel intermediary (e.g., Expedia.com) or a destination management organization (e.g., Visitfinland.com) to increase its turnover (Expedia), i.e. sell more hotel rooms, or to increase the number of tourists to the destination. Whereas, the user’s primary motivations for accessing the two systems is to find a suitable hotel and interesting events/attractions when visiting a destination [1]. In fact, there are various reasons as to why service providers may want to exploit this technology: Increase in sales: This goal is achieved because the recommended items are likely to satisfy users’ functional preferences. Presumably the user will recognize this after having tried several recommendations. From the service providers’ point of view, the primary goal of introducing a RS is to increase the conversion rate, i.e. the number of users that accept the recommendation and consume an item compared to the number of visitors browsing through for information. Exposure to a wider product range: Another major function of a RS is to enable the user to select items that might be hard to find without a precise recommendation. For instance, in a movie RS such as Netflix, the service 105 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org provider is interested in renting all the DVDs in the catalogue, not just the most popular ones. horror genre, then the system can learn to recommend other movies from this genre. Consolidating user satisfaction and fidelity: The user will find the recommendations interesting, relevant, and accurate, and when combined with a properly designed human-computer interaction she will also enjoy using the system. Personalization of recommendations improves user loyalty. Consequently, the longer the user interacts with the site, the more refined her user model becomes, i.e., the system representation effectively customizing recommendations to match the user’s preferences. Demographic: This type of system recommends items based on the demographic profile of the user. The assumption is that different recommendations should be generated for different demographic niches. Many Web sites adopt simple and effective personalization solutions based on demographics. For example, users are dispatched to particular Web sites based on their language or country. Or suggestions may be customized according to the age of the user. While these approaches have been quite popular in the marketing literature, there has been relatively little proper RS research into demographic systems. Improve QoS through customer feedback: Another important function of a RS, which can be leveraged to many other applications, is the description of the user’s preferences, either collected explicitly or predicted by the system. The service provider may then decide to reuse this knowledge for a number of other goals such as improving the management of the item’s stock or production. 1.2 Common Recommendation Techniques In order to implement its core function, identifying the useful items for the user, an RS must predict that an item is worth recommending. In order to do this, the system must be able to predict the utility of some of them, or at least compare the utility of some items, and then decide what items to recommend based on this comparison. The prediction step may not be explicit in the recommendation algorithm but we can still apply this unifying model to describe the general role of a RS. Some of the recommendation techniques are given below: Collaborative filtering: The simplest and original implementation of this approach recommends the items that other users with similar tastes liked, to the target user. The similarity of taste between two users is calculated based on the rating history of the users. Collaborative filtering is considered to be the most popular and widely implemented technique in RS. Neighbourhood methods focus on relationships between items or, alternatively, between users. An item-item approach models the preference of a user to an item based on ratings of similar items by the same user. Nearest-neighbours methods enjoy considerable popularity due to their simplicity, efficiency, and their ability to produce accurate and personalized recommendations. The authors will address the essential decisions that are required when implementing a neighbourhood based recommender system and provide practical information on how to make such decisions [2]. Content-based: The system learns to recommend items that are similar to the ones that the user liked in the past. The similarity of items is calculated based on the features associated with the compared items. For example, if a user has positively rated a movie that belongs to the Knowledge-based: Recommendation based on specific domain knowledge about how certain item features meet users’ needs and preferences and, ultimately, how the item is useful for the user. In these systems a similarity function estimates how well the user needs match the recommendation. The similarity score can be directly interpreted as the utility of the recommendation for the user. Content-based systems are another type of knowledge-based RSs In terms of used knowledge, both systems are similar: user requirements are collected; repairs for inconsistent requirements are automatically proposed in situations where no solutions could be found; and recommendation results are explained. The major difference lies in the way solutions are calculated. Knowledge-based systems tend to work better than others at the beginning of their deployment but if they are not equipped with learning components they may be surpassed by other shallow methods that can exploit the logs of the human/computer interaction (as in CF). 1.3 Problems in Existing Recommendation Systems Sparsity problem: In addition to the extremely large volume of user-item rating data, only a certain amount of users usually rates a small fraction of the whole available items. As a result, the density of the available user feedback data is often less than 1%. Due to this data sparsity, collaborative filtering approaches suffer significant difficulties in identifying similar users or items via common similarity measures, e.g., cosine measure, in turn, deteriorating the recommendation performance. Cold-start problem: Apart from sparsity, cold-start problem, e.g., users who have provided only little feedback or items that have been rated less frequently or even new users or new items, is a more serious challenge in recommendation research. Because of the lack of user feedback, any similarity-based approaches cannot handle such cold-start problem. Trustworthiness problem: Prediction accuracy in recommendation systems requires a great deal of 106 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org consideration as it has such a strong impact on customer experience. Noisy information and spurious feedback with malicious intent must be disregarded in recommendation considerations. Trust-driven recommendation methods refer to a selective group of users that the target user trusts and uses their ratings while making recommendations. Employing 0/1 trust relationships , where each trusted user is treated as an equal neighbour of the target user , proves to be rudimentary as it does not encapsulate the underlying level of trust between users. As a solution , the concept of Trust Relevancy [3] is introduced first , which measures the trustworthiness factor between neighbours , defining the extent to which the trusted user's rating affects the target user's predicted rating of the item. Next, the algorithm HybridTrustWalker performs a random walk on the weighted network. The result of each iteration is polymerised to predict the rating that a target user might award to an item to be recommended. Finally, we conduct experiments with a real-world dataset to evaluate the accuracy and efficiency of the proposed method. 2. Related Work Since the first paper published in 1998, research in recommendation systems has greatly improved reliability of the recommendation which has been attributed to several factors. Paolo Massa and Bobby Bhattacharjee in their paper Using Trust in Recommendation System: An Experimental Analysis (2004) show that any two users have usually few items rated in common. For this reason, the classic RS technique is often ineffective and is not able to compute a user similarity weight for many of the users. In 2005, John O'Donovan and Barry Smyth described a number of ways to establish profile-level and item-level trust metrics, which could be incorporated into standard collaborative filtering methods. Shao et al (2007) proposed a user-based CF algorithm using Pearson Correlation Coefficient (PCC) to compute user similarities. PCC measures the strength of the association between two variables. It uses historical item ratings to classify similar users and predicts the missing QoS values of a web service by considering QoS value of service used by users similar to her [4]. The most common trust-driven recommendation approaches make users explicitly issue trust statements for other users. Golbeck proposed an extended-breadth first-search method in the trust network for prediction called TidalTrust [5]. TidalTrust finds all neighbours who have rated the to-be recommended service/item with the shortest path distance from the given user and then aggregates their ratings, with trust values between the given user and these neighbours as weights. Mole Trust [6] is similar to TidalTrust but only considers the raters within the limit of a given maximum-depth. The maximum-depth is independent of any specific user and item. 3. Proposed System In a trust-driven recommendation [7] paradigm, the trust relations among users form a social network. Each user invokes several web services and rates them according to the interaction experiences. When a user needs recommendations, it predicts the ratings that the user might provide and then recommends services with high predicted ratings. Hence, the target of the recommendation system predicts users’ ratings on services by analysing the social network and user-service rating records. There is a set of users U = {u1, u2, ...,um} and a set of services S = {s1, s2, ..., sn} in a trust driven recommendation system. The ratings expressed by users on services/items are given in a rating matrix R = [Ru,s]mxn. In this matrix, Ru,s denotes the rating of user u on service (or item) s. Ru,s can be any real number, but often ratings are integers in the range of [3]. In this paper, without loss of generality, we map the ratings 1 ,…, 5 to the interval [0,1] by normalizing the ratings. In a social rating network, each user u has a set Su of direct neighbours, and tu,v denotes the value of social trust u has on v as a real number in [0, 1]. Zero means no trust, and one means full trust. Binary trust networks are the most common trust networks (Amazon, eBay, etc.). The trust values are given in a matrix T = [Tu,v]mxm. Non-zero elements Tu,v in T denote the existence of a social relation from u to v. Note that T is asymmetric in general [8]. u E-commerce Network u u u Zheng et al furthered the collaborative filtering dimension of recommendation systems for web service QoS prediction by systemically combining both item-based PCC (IPCC) and user-based PCC (UPCC). However, the correlation methods face challenges in providing recommendations for cold-start users as these methods consider users with similar QoS experiences for same services to be similar [3]. u u Web Services/Item s s s Fig. 1. Illustration of trust-driven recommendation approach 107 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Thus, the task of a trust-driven service recommendation system is as follows: Given a user u0 belonging to U and a service s belonging to S for which Ruo,s is unknown, predict the rating for u0 on service s using R and T. This is done by first determining a degree of trust between users in the social network to obtain a weighted social network from the Epinions data , using 0/1 trust relation from the input dataset and cosine similarity measures of user and service latent features. Then, a random walk performed on this weighted network yields a resultant predicted rating. Ratings over multiple iterations are polymerized to obtain the final predicted ratings. 3.1 Trust-Driven Recommendation Approach Incorporating trust metrics in a social network does not absolutely affect the target user’s ratings because the target user and trusted users might differ in interests, preferences and perception. The concept of trust relevancy considers both the trust relations between users together with the similarities between users. This section presents our approach in detail for trust-driven service recommendations. First, we define the concept of trust relevancy, on which our recommendation algorithm is based. Then, we introduce the algorithm HybridTrustWalker by extending the random walk algorithm in [7]. Lastly, the predicted ratings are returned. The methodology is summarized as shown in Fig. 2. t(u,v) is the degree of trust of u towards v. By computing the trust relevancy between all connected users in a social network, we can obtain a weighted trust network (SN+), where the weight of each edge is the value of trust relevancy. The aim of calculating trust relevancy is to determine the degree of association between trusted neighbours. In RSs, the user-item/service rating matrix is usually very large in terms of dimensionality but most of the score data is missing. Therefore, matrix factorization (MF) has been widely utilized in recommendation research to improve efficiency by dimension reduction [9]. For an m * n user-service rating matrix R, the purpose of matrix factorization is to decompose R into two latent feature matrices of users and items with a lower dimensionality d such that , R ≈ PQT (2) where P ∈ Rmxd and Q ∈ R nxd represent the user and item latent feature matrices, respectively. Each line of the respective matrix represents a user or service latent feature vector. After decomposing the matrix, we use the cosine similarity measure to calculate the similarity between two users. Given the latent feature vectors of two users, u and v, their similarity calculation is as follows: simU(u ,v) = cos(u ,v) = User Set , Service Set , Social network , Ratings (3) where u and v are latent feature vectors of users u and v. Trust Relevancy Calculation 3.2 Recommendation Algorithm The HybridTrustWalker algorithm attains a final result through multiple iterations. For each iteration, the random walk starts from the target user u0 in the weighted trust network SN+. In the kth step of the random walk in the trust network, the process will reach a certain node u. If user u has rated the to-be-recommended service s, then the rating of s from user u is directly used as the result for the iteration. Otherwise, the process has two options, one of which is: Weighted Network, User/Service Features Random Walk One result from each Iteration Ratings Prediction The random walk will stop at the current node u with a certain probability φu,s,k. Then, the service si is selected from RSu based on the probability Fu(si ). The rating of si from u is the result for the iteration. Termination condition based rating finalization Fig. 2. Proposed Methodology Given user u and v, the trust relevancy between u and v is as follows: tr(u,v) = simU(u,v) *t(u,v) (1) Here, simU(u,v) is the similarity of users u and v, and The probability that the random walk stops at user u in the k-th step is affected by the similarity of the items that u has rated and the to-be-recommended service s. The more similar the rated items and s, the greater the probability is to stop. Furthermore, a larger distance between the user u and the target user u0 can introduce more noise into the prediction. Therefore, the value of probability φu,s,k should increase when k increases [10]. 108 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Thus, the calculation for φu,s,k is as follows: φu,s,k = (si,s) * ∈ (4) where simS(si, s) is the similarity between the services si and s. The sigmoid function of k can provides value 1 for big values of k, and a small value for small values of k. In contrast to collaborative filtering techniques [2], this method can cope with services that do not have ratings from common users. Service similarities are calculated using Matrix Factorization [8]: SimS(si ,sj) = cos(si,sj) = (5) where tr(u, v) is the trust relevancy introduced earlier. The trust relevancy guarantees that each step of the walk will choose the user that is more similar to the current user, making the recommendation more accurate and thus enhancing productivity and user acceptance. 3.3 HybridTrustWalker Algorithm Input: U(user set), S(service set), R(rating matrix), SN+(weighted social network), u0(the target user), s(tobe-recommended service). Output: r (predicted rating). Pseudocode: When it is determined that user u is the terminating point of the walk, the method will need to select one service from RSu. The rating of si from u is the outcome for the iteration. The probability of the chosen service Fu(si ) is calculated according to the following formula: Fu(si )= ∑ ∈ 1 2 3 4 5 6 (6) 7 8 9 10 11 12 Services are selected Fu(si ) through a roulette-wheel selection [11], that is, services with higher values of Fu (si ) are more possible to be selected. Also, adopting the "six degrees of separation" [12], by setting the maximum step of each walk to 6, prevents infinite looping of the random walk. 13 14 15 16 17 18 19 20 21 Fig. 3. Example of HybridTrustWalker The other alternate option during the walk if the user u has not rated the to-be recommended service s is: The walk can continue with a probability of 1-φu,s,k. In which case, a target node for the next step is selected from the set of trusted neighbours of the user u. To distinguish different users’ contribution to the recommendation prediction, we propose that the target node v for the next step from the current user u is selected according to the following probability: Eu(v) = ∑ ∈ (7) set k = 1 ; //the step of the walk set u = u0 ; //set the start point of the walk as u0 set max-depth = 6 ; //the max step of the walk set r = 0 ; while (k<=max-depth) { u = selectUser(u) ; //select v from TUu as the target of the next step based on the probability Eu(v). if (u has rated s) { r = ru,s ; return r ; } else { if (random (0,1) < φu,s,k ||k == max-depth) { //stop at the current node si = selectService(u); //service si is selected from RSU based on the probability FU (si ). r = ru,si ; return r; } else k++ ; } } return r; Fig.3 shows an example to illustrate the algorithm clearly. The weight of each edge represents the probability Eu(v). Suppose the service s3 is to be recommended for the user u1. For the first step of the walk, u2 is more likely to be selected as the target node since the value of Eu(u2) is larger. If u2 has rated s3 with the rating r, r will be returned as the result of this walk (Line.7–9). Otherwise, if the termination condition (Line.12) is not reached, the walk would continue. For the second step, u5 is selected. It should also check whether u5 has rated s3. If u5 has not rated s3 but the termination condition is reached, it will select the most similar service to s3 from the items u5 has rated (Line.13). Then, the rating of the selected service by u5 is returned as the result of this walk. 109 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org RMSE into a precision metric in the range of [0, 1]. The precision is denoted as follows: 3.4 Ratings Prediction The HybridTrustWalker algorithm attains a final result through multiple iterations. The final predicted rating is obtained by polymerizing the results returned from every iteration: ∑ (8) puo,s where ri is the result of each iteration, n is the number of iterations. To obtain a stable predict result, the algorithm needs to perform an adequate number of random walks. We can decide the termination condition of the algorithm through the calculation of the variance of the prediction values. The variance of the prediction results after a random walk is denoted and calculated as: σi2 precision = 1 - (12) To combine RMSE and coverage into a single evaluation metric, we compute the F-Measure as follows : (13) F-Measure = Comparison analysis of performance measure for various RS paradigms including collaborative filtering approaches: Table 1: Comparing results for all users ∑ ̅ (9) where rj is the result of every iteration, i is the total number of iterations until the current walk, and σi2 the variance obtained from the last i iterations, which will eventually tend to a stable value. When |σi+12 - σi2| ≤ ε, the algorithm terminates ( = 0.0001). Algorithms RMSE Coverage (%) F-measure Item based CF 1.345 67.58 0.6697 User based CF 1.141 70.43 0.7095 Tidal trust 1.127 84.15 0.7750 Mole trust 1.164 86.47 0.7791 Trust Walker 1.089 95.13 0.8246 HybridTrustWalker 1.012 98.21 0.8486 4. Results and Discussion We use the dataset of Epinions published by the authors of [11]. The large size and characteristically sparse useritem rating matrix makes it suitable for our study. This contains data of 49,290 users who have rated 139,738 items. There are a total of 664,824 ratings with 487,181 trust relations within the network. We adopt the Root Mean Squared Error (RMSE), which is widely used in recommendation research, to measure the error in recommendations: 1.2 1 RMSE = √ ∑ 0.8 ̂ (10) 0.6 Precision 0.4 where Ru,s is the actual rating the user u gave to the service s and Ȓu,s: which is the predicted rating the user u gave to the service s. N denotes the number of tested ratings. The smaller the value of RMSE is, the more precisely the recommendation algorithm performs. We use the coverage metric to measure the percentage of pairs of <user, service>, for which a predicted value can be generated: Coverage = (11) where, S denotes the number of predicted ratings and N denotes the number of tested ratings. We have to convert Coverage 0.2 F-measure 0 Fig.4. Comparing results of all users. The reduction of precision of the proposed model is compensated by the increased coverage and F-measure as shown in Table 1 and Table 2 (in the case of cold-start users). 110 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Table 2: Comparing results of cold-start users Algorithms RMSE Coverage (%) F-measure Item based CF 1.537 User based CF 1.485 18.93 0.2910 Tidal trust 1.237 60.75 0.6463 Mole trust 1.397 58.29 0.6150 Trust Walker 1.212 74.36 0.7195 HybridTrustWalker 1.143 79.64 0.7531 23.14 0.3362 1.2 1 0.8 0.6 Precision 0.4 Furthermore, for this model, we develop a hybrid random walk algorithm. Existing methods usually randomly select the target node for each step when choosing to walk. By contrast, the proposed approach selects the target node based on trust and similarity. Thus, the recommendation contribution from trusted users is more accurate. We also utilize large-scale real data sets to evaluate the accuracy of the algorithm. The experimental results show that the proposed method can be directly applied in existing e-commerce networks with improved accuracy. Personalized service recommendation systems have been heavily researched in recent years and the proposed model provides an effective solution for the same. We believe that there is scope for improvement. For example, here, the trust relationships between users in the social trust network are considered to be invariant. But in reality, the trust relationship between users can change over time. In addition, the user ratings are also time sensitive. As a result, ratings that are not up-to-date may become noise information for recommendations. In large user communities, it is only natural that besides trust also distrust starts to emerge. Hence, the more users issuing distrust statements, the more interesting it becomes to also incorporate this new information. Therefore, we plan to include time sensitivity and the distrust factor in our future work. Coverage 0.2 F-measure 0 Acknowledgments The authors sincerely thank the authorities of Supercomputer Education and Research Center, Indian Institute of Science for the encouragement and support during the entire course of this work. Fig. 5 Comparing results of cold-start users References [1] Ricci, This means the ratings from most number of relevant users is considered during the rating prediction in each step of the walk in HybridTrustWalker. Due to cold-start users (Fig 5), item-based and user-based CF performs poorly. They have highest RMSE and lowest coverage than all the other algorithms considered during analysis. Due to the introduction of trust factor, TidalTrust, MoleTrust and TrustWalker have improved coverage compared to CF whereas precision does not change much. [2] [3] [4] 5. Conclusion The proposed recommendation system has three main objectives: (1) Tackling the problem of recommendations with cold-start users; (2) Address the problem of recommendations with a large and sparse user-service rating matrix and (3) Solve the problem with trust relations in a recommendation system. Thus, the main contributions of HybridTrustWalker presented in this paper, include, introducing the concept of trust relevancy, which is used to obtain a weighted social network. [5] [6] [7] Francesco, Lior Rokach, and Bracha Shapira. Introduction to recommender systems handbook. Springer US, 2011. Koren, Yehuda. "Factorization meets the neighborhood: a multifaceted collaborative filtering model." In Proceedings of the 14th ACM SIGKDD international conference on Knowledge discovery and data mining, pp. 426-434. ACM, 2008. Deng, Shuiguang, Longtao Huang, and Guandong Xu. "Social network-based service recommendation with trust enhancement." Expert Systems with Applications 41, no. 18 (2014): 8075-8084. Shao, Lingshuang, Jing Zhang, Yong Wei, Junfeng Zhao, Bing Xie, and Hong Mei. "Personalized qos prediction forweb services via collaborative filtering." InWeb Services, 2007. ICWS 2007. IEEE International Conference on, pp. 439-446. IEEE, 2007. Golbeck, Jennifer Ann. "Computing and applying trust in web-based social networks." (2005). Massa, Paolo, and Paolo Avesani. "Trust-aware recommender systems." InProceedings of the 2007 ACM conference on Recommender systems, pp. 17-24. ACM, 2007. Jamali, Mohsen, and Martin Ester. "Trustwalker: a random walk model for combining trust-based and item-based 111 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org recommendation." In Proceedings of the 15th ACM SIGKDD international conference on Knowledge discovery and data mining, pp. 397-406. ACM, 2009. [8] Sarwar, Badrul, George Karypis, Joseph Konstan, and John Riedl. Application of dimensionality reduction in recommender system-a case study. No. TR-00-043. Minnesota Univ Minneapolis Dept of Computer Science, 2000. [9] Koren, Yehuda, Robert Bell, and Chris Volinsky. "Matrix factorization techniques for recommender systems." Computer 8 (2009): 30-37. [10] Salakhutdinov, Ruslan, and Andriy Mnih. "Probabilistic Matrix Factorization Advances in Neural Information Processing Systems 21 (NIPS 21)."Vancouver, Canada (2008). [11] Lipowski, Adam, and Dorota Lipowska. "Roulette-wheel selection via stochastic acceptance." Physica A: Statistical Mechanics and its Applications 391, no. 6 (2012): 21932196. [12] Milgram, Stanley. "The small world problem." Psychology today 2, no. 1 (1967): 60-67. Mr. Pavan Kumar K N obtained his B.E. degree with distinction in Information Science and Engineering from Visvesvaraya Technological University. Presently he is taking up the position of Trainee Decision Scientist in Mu Sigma, Bangalore, India. His areas of interests include Data Analytics and Cyber Security. Ms. Samhita S Balekai received her B.E degree in Information Science and Engineering from Visvesvaraya Technological University. She secured an offer for the position of Software Engineer in Accenture, Bangalore, India. Her areas of interests are Data Analytics, Social Networks, Data Warehousing and Mining. Ms. Sanjana P Suryavamshi was awarded her B.E. degree with distinction in Information Science and Engineering from Visvesvaraya Technological University. Presently she is employed as a Software Engineer in Tata Consultancy Services (TCS), Bangalore, India. Her areas of interests are Networks and Cyber Security. Ms. Sneha Sriram earned her B.E. degree in Information Science and Engineering from Visvesvaraya Technological University. She is pursuing her M.S. degree in Information Technology Management from University of Texas, Dallas. Her areas of interests are Enterprise Systems and Information Technology. Dr. R. Bhakthavathsalam is presently working as a Principal Research Scientist in SERC, Indian Institute of Science, Bangalore. His areas of interests are Pervasive Computing and Communication, Wireless Networks and Electromagnetics with a special reference to exterior differential forms. Author held the position of Fellow of Jawaharlal Nehru Centre for Advanced Scientific Research during 1993 - 1995. He is a Member of IEEE Communication Society, ACM and CSI. 112 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Correlated Appraisal of Big Data, Hadoop and MapReduce Priyaneet Bhatia1, Siddarth Gupta2 1 Department of Computer Science and Engineering, Galgotias College of Engineering and Technology Uttar Pradesh Technical University Greater Noida, Uttar Pradesh 201306, India [email protected] 2 Department of Computer Science and Engineering, Galgotias University Greater Noida, Uttar Pradesh 203208, India [email protected] in real world scenarios. Section 3 describes the comparison between RDBMS and NoSQL and why NoSQL rather than RDBMS is used in today‟s world. Section 4 explores the Apache Hadoop in detail and its use in big data. Section 5 analyzes the MapReduce paradigm, its use in Hadoop paradigm, and its significance in enormous data reduction. Section 6 explicates the table comparisons of big data and Hadoop of various survey papers. Finally, the paper is concluded in the end. Abstract Big data has been an imperative quantum globally. Gargantuan data types starting from terabytes to petabytes are used incessantly. But, to cache these database competencies is an arduous task. Although, conventional database mechanisms were integral elements for reservoir of intricate and immeasurable datasets, however, it is through the approach of NoSQL that is able to accumulate the prodigious information in a proficient style. Furthermore, the Hadoop framework is used which has numerous components. One of its foremost constituent is the MapReduce. The MapReduce is the programming quintessential on which mining of purposive knowledge is extracted. In this paper, the postulates of big data are discussed. Moreover, the Hadoop architecture is shown as a master- slave procedure to distribute the jobs evenly in a parallel style. The MapReduce has been epitomized with the help of an algorithm. It represents WordCount as the criterion for mapping and reducing the datasets. Keywords: Big Data, Hadoop, MapReduce, RDBMS, NoSQL, Wordcount 2. Big Data Concepts 2.1 Outline of Big Data Let‟s start with big data. What is big data? Why has it created a buzz? Why is big data so essential in our daily chores of life? Where is it used? All these unanswerable questions have made everyone curious. Moving on, big data is actually a collection of large and complex datasets that has become very difficult to handle using traditional relational database management tools [5]. 1. Introduction As immense amount of data is being generated day by day, efficiency of storage capacity for this huge information becomes a painful task [1]. Therefore exabytes or petabytes of database known as big data need to be scaled down to smaller datasets through an architecture called Hadoop. Apache Hadoop is an open source framework on which the big data is processed with the help of MapReduce [2]. A programming model, MapReduce uses basic divide and conquer technique to its own map and reduce functions. On copious datasets it processes key/value pairs to generate intermediate key/value pairs and then, with the help of these pairs, merges the intermediate values to form a smaller sets of key/values sets [3][4]. The reduced data bytes of massive information are produced. The rest of the paper is formulated as follows. Section 2 covers the concepts of big data, its 3 V‟s and its applications 2.2 Four Vs‟ of Big Data Variety Velocity Volume Veracity 4V's of Big Data Figure 1: 4Vs‟ of Big Data Big data has its own 4 characteristics shown above in Fig 1 as: 113 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org i. Volume: refers to the amount of space or quantity of something. Since data is huge scaled complex sized, even larger than 1024 terabytes, it becomes a challenge to extract relevance information from traditional database techniques. E.g. the world produces 2.5 quintillion bytes in a year. 3.2 NoSQL NoSQL commonly refers to „Not Only SQL‟, has become a necessity in replacement to RDBMS, since its main characteristics focuses on data duplication and unstructured schemes. It allows unstructured compositions to be reserved and replicated across multiple servers for future needs. Eventually, no slowdown in performance occurs unlike in RDBMS. Companies such as Facebook, Google and Twitter use NoSQL for their high performance, scalability, availability of data with regards to the expectations of the users [11]. ii. Variety: represent the state of being varied or diversified. In this, all types of formats are available. Structured, unstructured, semistructured data etc. These varieties of formats are needed to be searched, analyzed, stored and managed to get the useful information. E.g.: geospatial data, climate information, audio and video files, log files, mobile data, social media etc [6]. 4. Hadoop 4.1 Hadoop in Brief iii. Velocity: the rate of speed with which something happens. In this, to deal with bulky spatial dimensional data which is streaming at an eccentric rate is still an eminent challenge for many organizations. E.g. Google produces 24 TB/day; Twitter handles 7 TB/day etc. Hadoop was created by Doug Cutting and Mike Caferella in 2005 [12]. It was named after his son‟s toy elephant [13]. It comprises of 2 components and other project libraries such as Hive, Pig, HBase, Zookeeper etc: a. iv. Veracity: refers to the accuracy of the information extracted. In this, data is mined for profitable purposes [7]. b. 2.3 Big Data in Real World Scenarios HDFS: open source data storage architecture with fault tolerant capacity. MapReduce: programming model for distributed processing that works with all types of datasets. [14]. 4.2 Motive behind Hadoop in Big Data a) Facebook generates 10-20 billions photos which is approximately equivalence to 1 petabytes. b) Earlier, hard copy photographs take space around 10 gigabytes in a canon camera. But, nowadays, digital camera is producing photographic data more than 35 times the old camera used to take and it is increasing day by day [8]. c) Videos on youtube are being uploaded in 72 hours/min. d) Data produced by google is approximately 100 peta-bytes per month [9]. Despite, one might get worried that since RDBMS is a dwindling technology, it cannot be used in big data processing; however, Hadoop is not a replacement to RDBMS. Rather, it is a supplement to it. It adds characteristics to RDBMS features to improve the efficiency of database technology. Moreover, it is designed to solve the different sets of data problems that the traditional database system is unable to solve. 4.3 CAP Theorem for Hadoop Cap theorem shown in Fig 2, can be defined as consistency, scalability and flexibility. 3. RDMS VS NOSQL a) Consistency: simultaneous transactions are needed in continuity for withdrawing from the account and saving into the account. b) Availability: flexibility in making multiples copies of data. If one copy goes down, then another is still accessible for future use. c) Partitioning: to partition the data in multiple copies for storage in commodity hardware. By default, 3 copies are normally present. This is to make for easy feasibility for the customers [15]. 3.1 RDBMS For several decades, relational database management system has been the contemporary benchmark in various database applications. It organizes the data in a well structured pattern. Unfortunately, ever since the dawn of big data era, the information comes mostly in unstructured dimensions. This culminated the traditional database system in not able to handle the competency of prodigious storage database. In consequence, it is not opted as a scalable resolution to meet the demands for big data [10]. 114 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org consistency 5.2 Principles of MapReduce a. CAP theorem partitioning b. availabilty c. Figure 2: CAP Theorem 4.4 Hadoop Business Problems d. i. ii. iii. iv. v. Marketing analysis: market surveys are being used to understand the consumer behaviours and improve the quality of the product. Lot of companies used feedback survey to study shopper attitudes. Purchaser analysis: It is best to understand the interest of the current customer rather than the new one. Therefore, the best thing is collect as much information as one can to analyze what the buyer was doing before he left the shopping mall. Customer profiling: it is essential to identify specific group of consumers having similar interest and preferences in purchasing goods from the markets. Recommendation portals: These online shopping browsers not only collect database from your own data but also from those users who match the profile of yours, so that these search engines can make recommend webites that are likely to be useful to you. E.g.: Flipkart, Amazon, Paytm, Myntra etc. Ads targeting: we all know ads are a great nuisance when we are doing online shopping, but they stay with us. These ad companies put their ads on popular social media sites so they can collect large amount of data to see what we are doing when we are actually shopping [16]. Lateral computing: provides parallel data processing across the nodes of clusters using the Java based API. It works on commodity hardware in case of any hardware failure. Programming languages: uses Java, Python and R languages for coding in creating and running jobs for mapper and reducer executables. Data locality: ability to move the computational node close to where the data is. That means, the Hadoop will schedule MapReduce tasks close to where the data exist, on which that node will work on it. The idea of bringing the compute to the data rather than bringing data to the compute is the key of understanding MapReduce. Fault tolerant with shared nothing: The Hadoop architecture is designed where the tasks have no dependency on each other. When node failure occurs, the MapReduce jobs are retried on other healthy nodes. This is to prevent any delays in the performance of any task. Moreover, these nodes failure are detected and handled automatically and programs are restarted as needed [18]. 5.3 Parallel Distributed Architecture The MapReduce is designed as the master slave framework shown in Fig 4, which works as job and task trackers. The master is the Jobtracker which performs execution across the mapper or reducer over the set of data. However, on each slave node, the Tasktracker executes either the map or reduce task. Each Tasktracker reports its status to its master. Jobtracker (master) TaskTracker (slave 1) TaskTracker (slave 2) TaskTracker (slave 3) Figure 3: Master Slave Architecture 5.4 Programming Model 5. MapReduce The MapReduce consists of 2 parts: map and reduce functions. 5.1 Understanding MapReduce MapReduce is a programming paradigm, developed by Google, which is designed to solve a single problem. It is basically used as an implementation procedure to induce large datasets by using map and reduce operations [17]. a) Map part: This is the 1st part of MapReduce. In this, when the MapReduce runs as a job, the mapper will run on each node where the data resides. Once it gets executed, it will 115 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org create a set of <key/value> pairs on each node. b) Reduce part: In the 2nd part of MapReduce, the reducer will execute on some nodes, not all the nodes. It will create aggregated sets of <key, value> pairs on these nodes. The output of this function is a single combined list. For each word in file contents: Emit (word, 1) Reducer (word, values): Sum=0 For each value in values Sum+= value Emit (word, sum) The pseudocode of MapReduce contains the mapper and reducer. The mapper has the filename and file contents and a loop for each to iterate the information. The word is emitted which has a value 1. Basically, spliiting occurs. In the reducer, from the mapper, it takes the output and produces lists of keys and values. In this case, the keys are the words and value is the total manifestation of that word. After that, zero is started as an initializer and loop occurs again. For each value in values, the sum is taken and value is added to it. Then, the aggregated count is emitted. Figure 4: MapReduce Paradigm Figure 4 displays the MapReduce prototype, comprised of three nodes under Map. Variegated categories of data have been represented through numerous colors in the Map. Accordingly, in essence, these nodes are running in three separate machines i.e. the commodity hardware. Thus, the chunks of information are implemented on discrete machines. Furthermore, the intermediate portion of this model resides the magical shuffle that is in fact quite complicated and hence is the key aspect of MapReduce. Literally, this framework has set the mind to think. How does this list come out from the Map function and is then aggregated to the Reduce function? Is this an automated process or some codes have to be written? Actually, in reality, this paradigm is the mixture of both. As a matter of fact, whenever the MapReduce jobs are written, the default implementations of shuffle and sort are studied. Consequently, all these mechanisms are tunable; one may accept the defaults or tune in or can change according to one‟s own convenience. 5.6 Example [21] Consider the question of counting the occurrence of each word in the accumulation of large documents. Let‟s take 2 input files and perform MapReduce operation on them. File 1: bonjour sun hello moon goodbye world File 2: bonjour hello goodbye goodluck world earth Map: First map: second map <bonjour, 1><bonjour,1> <sun,1><hello,1> <hello, 1><goodbye,1> <moon,1>< goodluck,1> <goodbye,1><world,1> <world,1><earth,1> 5.5 Word count Reduce: The Hello World of MapReduce program is the WordCount. It comes from Google trying to solve the data problem by counting all the words on the Web. It is de facto standard for starting with Hadoop programming. It takes an input as some text and produces a list of words and does counting on them. <bonjour, 2> <sun,1> <hello, 2> <moon,1> < goodluck,1> <goodbye,2> <world,2> <earth,1> Following below is the Pseudocode of WordCount [19][20]: Mapper (filename, file contents): 116 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Table 2: Approach on Hadoop 5.7 Algorithm Steps [22]: S.No a) Map step: in this step, it takes key and value pairs of input data and transform into output intermediate list of key/ value pairs. 1. ( Approach on Hadoop 2011 MapReduce, Linkcount, WordCount ) (1) b) Reduce step: in this step, after being shuffled and sorted, the output intermediate key/value pairs is passed through a reduce function where these values are merged together to form a smaller sets of values. ( ( )) (2) 6. Tabular Comparisons on Big Data and Hadoop Table 1: Approach on Big Data Author’s name 1. Puneet Singh Duggal et al 2. Min Chen et al P.Sara da Devi et al Year 2013 2014 2014 4. Poona m S. Patil et al 2014 5. K.Arun et al 2014 2. Puneet Duggal et al 2013 HDFS, MapReduce, joins, indexing, clustering, classification 3. Shreyas Kudale et al 2013 4. Poonam S. Patil et al 2014 5. Prajesh P. Anchalia et al 2014 HDFS, MapReduce, ETL, Associative Rule Mining HDFS, MapReduce, HBase, Pig, Hive, Yarn, k-means clustering algorithms 6. Radhika M. Kharode et al 2015 ) ( 3. Year ) ( S.No Author’s Name Mahesh Maurya et al Approach on Big Data Big Data analysis tools, Hadoop, HDFS, MapReduce Cloud computing, Hadoop Hadoop, extract transform load (ETL) tools like ELT, ELTL. RDBMS, NoSQL, Hadoop, MapReduce mining techniques like association rule learning, clustering classification Results/ Conclusion Used for storing and managing Big Data. Help organizations to understand better customers & market Focus on 4 phases of value chain of Big Data i.e., data generation, data acquisition, data storage and data analysis. Introduces ETL process in taking business intelligence decisions in Hadoop HDFS, MapReduce , k-means algorithms, cloud computing Results/ Conclusion Experimental setup to count number of words & links (double square brackets) available in Wikipedia file. Results depend on data size & Hadoop cluster. Studied Map Reduce techniques implemented for Big Data analysis using HDFS. Hadoop„s not an ETL tool but platform supports ETL processes in parallel. Parallelize & distribute computations tolerant. Experimental setup for MapReduce technique on kmeans clustering algorithm which clustered over 10 million data points. Combination of data mining & Kmeans clustering algorithm make data management easier and quicker in cloud computing model. 7. Conclusion To summarize, the recent literature of various architectures have been surveyed that helped in the reduction of big data to simple data which mainly composed of immense knowledge in gigabytes or megabytes. The concept of Hadoop, its use in big data has been analyzed and its major component HDFS and MapReduce have been exemplified in detail. Overall, the MapReduce model is illustrated with its algorithm and an example for the readers to understand it clearly. To sum up, applications of big data in real world scenario has been elucidated. Study challenges to deal analysis of big data. Gives flexibility to use any language to write algorithms. Study big data classifications to business needs. Helps in decision making in business environment by implementing data mining techniques, Acknowledgements Priyaneet Bhatia and Siddarth Gupta thanks Mr. Deepak Kumar, Assistant Professor, Department of Information Technology, and Rajkumar Singh Rathore, Assistant Professor, Department of Computer Science and Engineering, Galgotia 117 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org College of Engineering and Technology, Greater Noida, for their constant support and guidance throughout the course of whole survey. [15] [16] References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] Shreyas Kudale, Advait Kulkarni and Leena A. Deshpande, “Predictive Analysis Using Hadoop: A Survey”, International Journal of Innovative Research in Computer and Communication Engineering, Vol. 1, Issue 8, 2013. pp 1868-1873 P.Sarada Devi, V.Visweswara Rao and K.Raghavender, “Emerging Technology Big Data Hadoop Over Datawarehousing, ETL” in International Conference (IRF), 2014, pp 30-34. Jeffrey Dean and Sanjay Ghemawat, “MapReduce: Simplified Data Processing on Large Clusters”, Google, Inc in USENIX Association OSDI ‟04: 6th Symposium on Operating Systems Design and Implementation, 2009, pp 137-149. 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Mahesh Maurya and Sunita Mahajan ,“Comparative analysis of MapReduce job by keeping data constant and varying cluster size technique”, Elseveir, 2011, pp 696-701 Dhole Poonam and Gunjal Baisa, “Survey Paper on Traditional Hadoop and Pipelined Map Reduce”, International Journal of Computational Engineering Research (IJCER), Vol. 3, Issue 12, 2013, pp 32-36 MapReduce, Apache Hadoop, Yahoo Developer Network, https://developer.yahoo.com/hadoop/tutorial/modul e4.html Mahesh Maurya and Sunita Mahajan, “Performance analysis of MapReduce programs on Hadoop Cluster” IEEE, World Congress on Information and Communication Technologies (WICT2012), 2012, pp 505-510. Ms. Vibhavari Chavan and Prof. Rajesh. N. Phursule, “Survey Paper on Big Data”, International Journal of Computer Science and Information Technologies (IJCSIT), Vol. 5, No.6, 2014, pp 7932-7939. Radhika M. Kharode and Anuradha R. Deshmukh, “Study of Hadoop Distributed File system in Cloud Computing”, International Journal of Advanced Research in Computer Science and Software Engineering (IJARCSSE) , Vol.5, Issue 1, 2015, pp 990-993. First Author Priyaneet Bhatia has done her B.Tech in IT from RTU, Jaipur, Rajasthan, India in 2012. Currently, she is pursuing M.Tech in CSE from Galgotia College of Engineering and Technology, UPTU, Greater Noida, Uttar Pradesh, India. She is working on the project “Big Data in Hadoop MapReduce”. Second Author Siddarth Gupta has done B.Tech in CSE from UPTU, Lucknow, Uttar Pradesh, India in 2012.He has completed M.tech in CSE from Galgotias University, Greater Noida, Uttar Pradesh, India in May 2015. He is currently working on “Big Data optimization in Hadoop” 118 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Combination of PSO Algorithm and Naive Bayesian Classification for Parkinson Disease Diagnosis Navid Khozein Ghanad1,Saheb Ahmadi 2 1 Islamic Azad university Of Mashhad, Faculty of Engineering, Department Of Computer, Mashhad, Iran [email protected] 2 Islamic Azad university Of Mashhad, Faculty of Engineering, Department Of Computer, Mashhad, Iran [email protected] Abstract significantly low symptoms [1]. It is claimed that 90% of Parkinson is a neurological disease which quickly affects human’s motor organs. Early diagnosis of this disease is very Parkinson patients can be recognized important for its prevention. Using optimum training data and Through voice disorders[2]. Parkinson patients have a set omitting noisy training data will increase the classification of voice disorders by which their disease can be accuracy. In this paper, a new model based on the combination of diagnosed. These voice disorders have indices whose PSO algorithm and Naive Bayesian Classification has been measurement can be used for diagnosing the disease [3] presented for diagnosing the Parkinson disease, in which [4]. In the previous studies, problems of Parkinson disease optimum training data are selected by PSO algorithm and Naive diagnosis were considered. Using SVM Classification with Bayesian Classification. In this paper, according to the obtained Gaussian kernel, the obtained result was 91.4% at best [4]. results, Parkinson disease diagnosis accuracy has been 97.95% In order to diagnose the Parkinson disease, a new non- using the presented method, which is indicative of the superiority of this method to the previous models of Parkinson disease linear model based on Dirichlet process mixing was diagnosis. presented and compared with SVM Classification and decision tree. At best, the obtained result was 87.7% [5]. Keywords: Parkinson disease diagnosis, Naive Bayesian In [6], different methods have been used to diagnose the Classification, PSO algorithm Parkinson disease, in which the best result pertained to the classification using the neural network with 92.9% accuracy. In [7], the best features were selected for SVM 1. Introduction Classification through which 92.7% accuracy could be Parkinson disease is one of the nervous system diseases, obtained at best. In [8], using sampling strategy and multi- which causes quivering and losing of motor skills. Usually class multi-kernel relevance vector machine method this disease occurs more in people over 60 years old, and 1 improvement, 89.47% accuracy could be achieved. In [9], out of 100 individuals suffers from this disease. However, the combination of Genetic Algorithm and Expectation it is also observed in younger people. About 5 to 10% of Maximization Algorithm could bring 93.01% accuracy for patients are in younger ages. After Alzheimer, Parkinson is Parkinson disease diagnosis. In [10], using fuzzy entropy the second destructive disease of the nerves. Its cause has measures, the best feature was selected for classification not been recognized yet. In the first stages, this disease has and thereby 85.03% accuracy could be achieved for 119 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org classification. In [11], the combination of non-linear fuzzy and the objective function f(x) from a set like V. Bayesian method and SVM Classification could detect the speaker’s method for the new sample classification is such that it gender with 93.47% accuracy. In [12], the combination of detects the most probable class or the target value vMAP RF and CFS algorithms could diagnose the Parkinson having trait values<a1,a2,…an>, which describes the new disease with 87.01% accuracy. In [13], using parallel sample. forward neural network, Parkinson disease was diagnosed vmap=argvi=vmax p(vj I a1, a2,…….,an) with 91.20% accuracy. In [14], with improvements in OPF Using Bayesian ’ theorem, term (1) can be rewritten as Classification, Parkinson disease was diagnosed with term (2): (1) 84.01% accuracy. In [15], fuzzy combination with the Nearest Neighbor Algorithm could achieve 96.07% Vmap=argvi=vmax accuracy. In [16] and [17], by focusing on voice analysis, ( ) ( ( ) ) =argvi=vmaxP(a1,a2,…..,an,Ivj)P(vj) (2) they attempted to gain 94% accuracy. In the previous presented methods, attempts have been made to offer the Now using the training data, we attempt to estimate the best classification methods and no attention has been paid two terms of the above equation. Computation based on to the quality of the training data. In this paper, we the training data to find out what is the repetition rate of v j presented a new model based on the combination of PSO algorithm and Naive Bayesian Classification in the data, is easy. However, computation of different for terms P(a1,a2,…an | Vj) by this method will not be diagnosing the Parkinson disease. This algorithm selects acceptable unless we have a huge amount of training data the best training data for Naive Bayesian Classification available. The problem is that the number of these terms is and this causes no use of non-optimal training data. Due to equal to the number of possible samples multiplied by the using optimum training data and not using non-optimal number of the objective function values. Therefore, we training data, this new model presented in this paper should observe each sample many times so that we obtain increases the classification accuracy and Parkinson disease an appropriate estimation. diagnosis to 97.95%. Objective function output is the probability of observing First we consider Naive Bayesian Classification and PSO the traits a1,a2,…an equal to the multiplication of separate algorithm. Then, the presented algorithm, results and probabilities of each trait. If we replace it in Equ.2, it references will be investigated. yields the Naive Bayesian Classification, i.e. Equ.3: 1.1. Naive Bayesian Classification VNB=arg max P(Vj) ∏ ( One very practical Bayesian learning method is naive | ) (3) Where vNB is Naive Bayesian Classification output for the Bayesian learner which is generally called the Naive objective function. Note that the number of terms P(ai|vj) Bayesian Classification method. In some contexts, it has that should be computed in this method is equal to the been shown that its efficiency is analogous to that of the number of traits multiplied by the number of output classes methods such as neural network and decision tree. for the objective function, which is much lower than the Naive Bayesian classification can be applied in problems number of the terms P(a1,a2,…an | Vj) in which each sample x is selected by a set of trait values 120 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org We conclude that naive Bayesian learning attempts to the sake of maintaining the algorithm’s probabilistic estimate different values of P(vj) and P(ai|vj) using their property. Each particle’s next speed is obtained by Equ.5: repetition rate in the training data. This set of estimations Xi+1=Xi+Vi+1 (5) corresponds to the learnt assumption. After that, this assumption is used for classifying the new samples, which 2. Considering the presented algorithm is done through the above formula. When conditional independence assumption of Naive Bayesian Classification In the introduction section, we considered that different method is estimated, naive Bayesian class will be equal to methods have been presented for Parkinson disease the MAP class. diagnosis, but no attention has been paid to the quality of the training data. In this paper, we attempt to select the best training data using PSO algorithm for Naive Bayesian 1.2. PSO algorithm Classification. The selection of the best training data is the most important part for training the Naive Bayesian Each particle is searching for the optimum point. Each Classification training. This is due to the fact that we particle is moving, thus it has a speed. PSO is based on the observed in our studies that adding or omitting two particles’ motion and intelligence. Each particle in every training data in the whole set of training data caused 4 to stage remembers the status that has had the best result. 5% more accuracy in disease diagnosis. The suggested method will be introduced in detail in the following. Particle’s motion depends on 3 factors: 1- Particle’s current location The diagram below shows the general procedure of the 2- Particle’s best location so far (pbest) new presented algorithm. 3- The best location which the wholeset of particles were in so far (gbest) In the classical PSO algorithm, each particle i has two main parts and includes the current location, and Xiis the particle’s current speed (Vi). In each repetition, particle’s change of location in the searching space is based on the particle’s current location and its updated speed. Particles’ speed is updated according to three main factors: particle’s current speed, particle’s best experienced location (individual knowledge), and particle’s location in the best status of group’s particles (social knowledge), as Equ.4. Vi+1 =K(wVi+C1i(Pbest i– Xi) + C1i(Gbesti - Xi)) (4) th Where W is the i particle’s inertia coefficient for moving with the previous speed. C1i and C2i are respectively the individual and group learning coefficients of the ith particle, which are selected randomly in range {2-0} for 121 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Table1. Primary values given to PSO algorithm parameters No. 1 Bird in swarm The used parameter value 50 2 Number of Variable 1 3 Min and Max Range 2-46 4 Availability type Min 5 Velocity clamping factor 2 6 Cognitive constant 2 7 Social constant 2 8 min of inertia weight 0.4 9 max of inertia weight 0.4 Start Selecting the best training data and the intended parameters for naive Bayesian training using PSO algorithm Naive Bayesian Classification training using the best training data and forming the Parkinson disease diagnosis model Parkinson disease diagnosis through the formed model Parameter title 3. Experiments and results End 3.1. Dataset descriptions Fig1. The procedure of the suggested method for Parkinson disease In this article, we used the dataset of the Parkinson disease diagnosis belonging to UCI. This dataset is accessible through this The general procedure is very simple. In this paper, first link [18]. The number of the items of this dataset is 197, the best data for Naive Bayesian Classification are selected and its features are 23. Features used in Parkinson disease using PSO algorithm, and Naive Bayesian Classification is diagnosis are presented in Table2: trained by the optimum training data. Thereby, the Parkinson disease diagnosis model is formed. After the formation of the intended model, the Parkinson disease is diagnosed and identified. PSO algorithm fitness function for the selection of the optimum training data is expressed in Equ.6: Fitness = where ∑ | | (6) is the real value of the test data, and is the value that has been determined using Naive Bayesian Classification. Values of the primary parameters of PSO algorithm for the selection of the optimum training data are presented in Table1. 122 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Table3. The accuracy of Parkinson disease diagnosis class using the Table2. Features used in Parkinson disease diagnosis 1 MDVP: FO(HZ) 2 MDVP: Fhi (HZ) 3 MDVP: Flo(HZ) 4 5 6 7 8 9 MDVP: Jitter (%) MDVP: Jitter (Abs) MDVP: RAP MDVP: PPQ Jitter: DDP MDVP: Shimmer 10 11 12 13 14 15 MDVP: Shimmer (dB) Shimmer : APQ3 Shimmer : APQ5 MDVP :APQ Shimmer :DDA NHR 16 17 18 19 20 21 22 NHR RPDE DFA Spread 1 optimum training data selected by PSO algorithm Average vocal fundamental frequency Maximum vocal fundamental frequency Minimum vocal fundamental frequency The number of the optimum training data No. selected for Naive Classification accuracy Bayesian Classification using PSO algorithm Several measures of variation in fundamental frequency 1 8 97.95% 2 10 96.93% 3 12 97.95% In Table3, some of the optimum training data selected using PSO algorithm along with the classification accuracy obtained through the optimum training data can be found. As can be seen in No. 2 of Table3, by adding two training Two measures of ratio of noise to tonal components in the voice data, classification accuracy has decreased 1.02%. Therefore, it can be concluded that by increasing the training data, there is no guarantee that classification accuracy be increased. The important point in increasing the classification accuracy is the use of optimum training Two nonlinear dynamical complexity measure data and no use of noisy training data which decrease the classification accuracy. We increased the number of Spread 2 D2 PPE training data respectively to 50, 60, 70, 80 and 90 training data. The accuracy of the obtained results of this high number of training data can be observed in Table4. 3.2. The optimum training data selected for Naive Bayesian Classification using PSO algorithm Table4. The relationship between Parkinson disease diagnosis accuracy and training data increase As stated in the previous sections, selecting the best The number of the No. training data is the most important part of Naive Bayesian Classification accuracy trainingdata Classification for increasing the accuracy and Parkinson disease diagnosis. In Table3, the number of the optimum training data selected by PSO algorithm can be observed: 1 50 88.79% 2 60 77.55% 3 70 76.53% 4 80 69.38% 5 90 67.54% 123 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org In Table4, we can see that using Naive Bayesian Bayesian Classification. Due to the fact that this presented Classification with increasing the training data will algorithm selects the best training data and avoids decrease the classification accuracy. choosing those that cause drop and decrease in According to the optimum training data selected by PSO classification accuracy, it gets the classification accuracy algorithm, it is concluded that by having only 8 training and Parkinson disease diagnosis to 97.95%. This data, the highest accuracy in the possible classification can classification accuracy shows the superiority of the be obtained for Parkinson disease diagnosis. suggested method to the previous models of Parkinson In Table5, the result of the algorithm presented in this disease diagnosis. Also, according to the result obtained in paper is compared with the results of the previous works: the paper, it can be reminded that in order to increase the classification accuracy, it is not always necessary to Table5. Comparison of the suggested method’s accuracy and previous present a new classification method; rather by selecting the models of Parkinson disease diagnosis best training data and omitting the inappropriate training Result and accuracy of No. data, classification accuracy can be significantly increased. Presented works the presented model 1 [9] 93.01% References 2 [11] 93.01% 3 [13] 91.20% 4 [15] 96.01% 5 [16][17] 94% 6 Proposed Algorithm 97.95% [1] Singh, N., Pillay, V., &Choonara, Y. E. (2007). Advances in the treatment of Parkinson’s disease. Progress in Neurobiology.81,29-44 [2] Ho, A. K., Iansek, R., Marigliani, C., Bradshaw, J. L., & Gates, S. (1998).Speechimpairment in a large sample of patients with Parkinson’s disease. Behavioural Neurology, 11,131-138 [3] Little, M. A., McSharry, P. E., Hunter, E. J., Spielman, J., &Ramig, L. O (2009). Suitability of dysphonia measurements for telemonitoring of Parkinson’s disease. IEEE Transactions on Biomedical Engineering, 56(4), 1015–1022 [4] Rahn, D. A., Chou, M., Jiang, J. J., & Zhang, Y. (2007). Phonatory impairment in Parkinson’s disease: evidence from nonlinear dynamic analysis and perturbation analysis. Journal of Voice, 21, 64–71. [5] Shahbaba, B., & Neal, R. (2009). Nonlinear models using Dirichlet process mixtures.The Journal of Machine Learning Research, 10, 1829–1850. [6] Das, R. (2010). A comparison of multiple classification methods for diagnosis of Parkinson disease. Expert Systems with Applications, 37, 1568–1572. [7] Sakar, C. O., &Kursun, O. (2010). Telediagnosis of Parkinson’s disease using measurements of dysphonia. Journal of Medical Systems, 34, 1–9 [8] Psorakis, I., Damoulas, T., &Girolami, M. A. (2010). Multiclass relevance vectormachines: sparsity and accuracy. Neural Networks, IEEE Transactions on, 21,1588–1598. [9] Guo, P. F., Bhattacharya, P., &Kharma, N. (2010). Advances in detecting Parkinson’s disease. Medical Biometrics, 306–314. According to the comparison made between the suggested method and the previous models of Parkinson disease diagnosis in Table5, it is shown that the suggested method is superior to the previous models of Parkinson disease diagnosis. Based on the comparison it can be concluded that in order to increase the classification accuracy, it is not always necessary to present a new classification method; rather by selecting the best training data and omitting the inappropriate training data, classification accuracy can be significantly increased. 4. Conclusion In this paper, we suggested a new model for Parkinson disease diagnosis based on the combination of PSO algorithm and Naive Bayesian Classification. Using PSO algorithm, the best training data were selected for Naive 124 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [10] Luukka, P. (2011). Feature selection using fuzzy entropy measures with similarity classifier. Expert Systems with Applications, 38, 4600–4607. [11] Li, D. C., Liu, C. W., & Hu, S. C. (2011). A fuzzybased data transformation for feature extraction to increase classification performance with small medical data sets. Artificial Intelligence in Medicine, 52, 45–52. [12] Ozcift, A., &Gulten, A. (2011). Classifier ensemble construction with rotation forest to improve medical diagnosis performance of machine learning algorithms. Comput Methods Programs Biomed, 104, 443–451. [13] AStröm, F., &Koker, R. (2011). A parallel neural network approach to prediction of Parkinson’s Disease. Expert Systems with Applications, 38, 12470–12474. [14] Spadoto, A. A., Guido, R. C., Carnevali, F. L., Pagnin, A. F., Falcao, A. X., & Papa, J. P. (2011). Improving Parkinson’s disease identification through evolutionarybased feature selection. In Engineering in Medicine and Biology Society, EMBC, 2011 Annual International Conference of the IEEE (pp. 7857–7860). [15] Hui-Ling Chen a, Chang-Cheng Huang a, Xin-Gang Yu b, Xin Xu c, Xin Sun d, Gang Wang d, Su-Jing Wang(2013). An efficient diagnosis system for detection of Parkinson’s disease using fuzzy k-nearest neighbor approach. In Expert Systems with Applications 40 (2013) 263–271 [16] Yoneyama, M.;kurihara, y.;watanabe,k;mitoma, h. accelerometry-Based Gait Analysis and Its Application to Parkinson's Disease Assessment— Part 1: Detection of Stride Event(Volume:22 , Issue: 3)page:613-622, May 2014 [17] Yoneyama, M.;kurihara, y.;watanabe,k;mitoma, h.Accelerometry-Based Gait Analysis and Its Application to Parkinson's Disease Assessment— Part 2: New Measure for Quantifying Walking Behavior (Volume:21 , Issue: 6)page:999-1005,Nov. 2013 [18] UCI machine learning repository. (http://archive.ics.uci.edu/ml/datasets/Parkinsons) 125 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Automatic Classification for Vietnamese News Phan Thi Ha1, Nguyen Quynh Chi2 1 Posts and Telecommunications Institute of Technology Hanoi, Vietnam [email protected] 2 Posts and Telecommunications Institute of Technology Hanoi, Vietnam [email protected] and processing and classifying documents by topic has been interested and researched on the worldwide [2]. Therefore, they build the methods of text classification to strongly support for finding information of Internet users. Abstract This paper proposes an automatic framework to classify Vietnamese news from news sites on the Internet. In this proposed framework, the extracted main content of Vietnamese news is performed automatically by applying the improved performance extraction method from [1]. This information will be classified by using two machine learning methods: Support vector machine and naïve bayesian method. Our experiments implemented with Vietnamese news extracted from some sites showed that the proposed classification framework give acceptable results with a rather high accuracy, leading to applying it to real information systems. Keywords: news classification; automatic extraction; support vector machine, naïve bayesian networks This paper proposes an automatic framework to classify Vietnamese news from electronic newspaper on the Internet under Technology, Education, Business, Law, Sports fields to build archives which serve the construction of internet electronic library of Vietnam. In this proposed framework, the extracted main content of Vietnamese news is performed automatically by applying the improved performance extraction method from [1]. This information will be classified by using two machine learning methods: Support vector machine and naïve bayesian method. Our experiments implemented with Vietnamese news extracted from some sites showed that the proposed classification framework gives an acceptable result with a rather high accuracy, leading to applying it to real information systems. 1. Introduction In the modern life, the need to update and use of information is very essential for human’s activities. Also we can see clearly the role of information in work, education, business, research to modern life. In Vietnam, with the explosion of information technology in recent years, the demand for reading newspapers, searching for information on the Internet has become a routine of each person. Because of many advantages of Vietnamese documents on the Internet such as compact and long-time storage, handy in exchange especially through the Internet, easy modification, the number of document has been increasing dramatically. On the other hand, the communication via books has been gradually obsolete and the storage time of document can be limited. The rest of the paper is presented as the followings. In section 2, the methods of news classification based on automatically extracted contents of Web pages on the Internet are considered. The main content of the automatic classification method is presented in section 3. Our experiments and the results are analyzed and evaluated in section 4. The conclusions and references are the last section. 2. Related works and motivation From that fact, the requirement of building a system to store electronic documents to meet the needs of academic research based on the Vietnamese rich data sources on the site. However, to use and search the massive amounts of data and to filter the text or a part of the text containing the data without losing the complexity of natural language, we cannot manually classify text by reading and sorting of each topic. An urgent need to solve the issue is how can automatically classify the document on the Vietnamese sites. Basically, the sites will contain pure text information In recent years, natural language processing and document content classification have had a lot of works with encouraging results of the research community inside and outside Vietnam. The relevant works outside Vietnam have been published a lot. In [3], they used clustering algorithm to generate the sample data. They focused on optimizing for active machine learning. An author at University of Dortmund 126 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Germany presented that the use and improvement of support vector machine (SVM) technique has been highly effective in text classification [4]. The stages in the a text classification system including indexing text documents using Latent semantic Indexing (LSI), learning text classification using SVM, boosting and evaluating text categorization have been shown in [5]. “Text categorization based on regularized linear classification methods” [6] focused in methods based on linear least squares techniques fit, logistic regression, support Vector Machine (SVM). Most researchers have focused on processing for machine learning and foreign language, English in particularly. In the case of applying for Vietnamese documents, the results may not get the desired accuracy. In recent years, extracting contents of the site have been researched by many groups in countries and their results were rather good [16, 17, 18, 19, 1]. These approaches include: HTML code analysis; pattern framework comparison; natural language processing. The method of pattern framework extracts information from two sites. This information is then aligned together based on the foundation of pattern recognition applied by Tran Nhat Quang [18]. This author extracted content on web sites aiming to provide information on administration web sites. The method of natural language processing considers the dependence of syntax and semantics to identify relevant information and extract needed information for other processing steps. This method is used for extracting information on the web page containing text following rules of grammar. HTML method accesses directly content of the web page displayed as HTML then performs the dissection based on two ways. The first is based on Document Object Model tree structure (DOM) of each HTML page, data specification is then built automatically based on the dissected content. The second is based on statistical density in web documents. Then, dissect the content, data obtained will become independent from the source sites, it is stored and reused for different purposes. The work of Vietnamese text categorization can be mentioned by Pham Tran Vu et al. They talked about how to compute the similarity of text based on three aspects: the text, user and the association with any other person or not [7]. The authors applied this technique to compute the similarity of text compared with training dataset. Their subsequent work referred matching method with profiles based on semantic analysis (LSA). The method presented in [8] was without the use of ontology but still had the ability to compare relations on semantics based on the statistical methods. The research works in Vietnam mentioned have certain advantages but the scope of their text processing is too wide, barely dedicated for a particular kind of text. Moreover, the document content from Internet is not extracted automatically by the method proposed in [1]. Therefore, the precision of classification is not consistent and difficult to evaluate in real settings. To automatically extract text content from the web with various sources, across multiple sites with different layouts, the authors [1] studied a method to extract web pages content based on HTML tags density statistics. With the current research stated above, we would like to propose a framework for automatic classification of news including Technology, Education, business, Law, Sports fields. We use the method in [1] which is presented in the next section. To extract document content on the Internet, we must mention to the field of natural language processing – a key field in science and technology. This field includes series of Internet-related applications such as: extracting information on the Web, text mining, semantic web, text summarization, text classification... Effective exploitation of information sources on the Web has spurred the development of applications in the natural language processing. The majority of the sites is encoded in the format of Hyper Text Mark-up Language (HTML), in which each Web page’s HTML file contains a lot of extra information apart from main content such as pop-up advertisements, links to other pages sponsors, developers, copy right notices, warnings…Cleaning the text input here is considered as the process of determining content of the sites and removing parts not related. This process is also known as dissection or web content extraction (WCE). However, structured websites change frequently leading to extracting content from the sites becomes more and more difficult [9]. There are a lot of works for web content extraction, which have been published with many different applications [10, 11, 12, 13, 14, 15]. 3. Automatic News Classification 3.1 Vietnamsese classification web content extraction for The authors have automatically collected news sites under 5 fields from the Internet and used content dissection method based on word density and tag density statistics of the site. The extracting text algorithm was improved from the algorithm proposed by Aidan Finn [11] and the results were rather good. Aidan Finn proposed the main idea of BTE algorithm as follows: Identify two points i, j such that some HTML tagtokens under i and on j is maximum and the signs of texttokens between i and j is maximum. The extraction result is the text signs between interval [i, j] which are separated. Aidan Fin did experiments by using BTE algorithm to extract text content for textual content classification in 127 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org digital libraries, mainly collecting new articles in the field of sports and politics in the news website. This algorithm has the advantage that dissection does not depend on the given threshold or language but the algorithm is not suitable for some Vietnamese news sites containing some advanced HTML tags. encode[] array, which significantly reduces the size of binary_tokens[] array. The complexity of this algorithm is O(n) Step 2: Locate two points i, j from binary_tokens[] array recently obtained in step 1 so that the total number of elements which have value -1 between [i, j] and 1 outside [i, j] is the largest. Perform data dissection in the scope [i, j] and remove HTML tags. The complexity of this algorithm is O(n3). By observing some different Vietnamese news sites, the paper [1] showed that the news sites in general have a main characteristic: in each page’s HTML code, text body part contains fewer tags and many signs of text. The authors have improved algorithm BTE (by adding step 0) to extract text body from Vietnamese new sites to build Vietnamese vocabulary research corpus. The BTE-improved algorithm is tested and compared with original algorithm proposed by Aidan Finn with the same number of sites in the test set. The experiments and results are as follows: Construction algorithm: The experimental observations show that the text body of Web pages always belong to a parent tag that is located in pair (<body> … </ body>) in which HTML tags like or scripts is embedded in tags like <img> <input> <select> <option>… In addition, some content is not related to the text body but in some advanced HTML tags like (<style> … </ style> <script> … </ Script>, <a>….</a>,…). Therefore, initial step should be removing the HTML code which certainly does not contain the content of the web page (Step 0). Then binary encoding of remaining content (HTML tags corresponding to 1, text signals corresponding -1) is performed then total of identical adjacent value is computed. Next, extract segments which have the most negative values (-1) and the least positive values (1). The complexity of this algorithm is O (n2). First time: run BTE algorithm of Aidan Finn on HTML file obtained respectively from the URL. Second time: run improved BTE on HTML file obtained respectively from the URL. The ratio of text body needed over the total extraction text of 3 types of sites which are interested by many users is shown in table 1, in which each type of collected sites contains 100 files. Table 1. Comparing ratio of text body needed to take/total of extraction text Here are main steps of the algorithm: Step 0: Each site corresponds to one HTML file format. Clean HTML codes by removing tags, HTML codes do not contain information relating to contents such as tags: <input>, <script>, <img>, <style>, <marquee>,<!--...-->, <a>… and contents outside the HTML tags <body>,</body> of each web page. HTML tags library is collected from web site address [22, 23]. Aidan Finn’s algorithm 47.12% Dantri.com.vn Improved algorithm 99.02% Vietnamnet.vn 99.67% 65.71% VnExpress.net 99.00% 48. 87% Type of site 3.2 News web content classification We use a learning machine method called support vector machine (SVM) to train a 5 types classifier for news classification on webs. This is a multi-class classification problem. The idea of solving a multi-class classification problem is to convert it into two-class problems by constructing multiple classifiers. The common multi-class classification strategy are: One-Against_One (OAO), and One-Against- Rest (OAR). Step 1: For the remaining part of the web sites, build two arrays that are binary_tokens[] and tokens[]. Binary_tokens[] include 1 and -1: - Binary_tokens[i] = 1 corresponds to the ith element which is an HTML tag. This tag includes the beginning tags: <?...>, example: <html>, <p color = red> and end tags: </?...>, example: </html>, </p>. With OAR strategy (Fig 1), we will use K-1 binary classifiers to build K-class. The K-class classification problem is converted into K-1 two-class classification problems. In particular, the ith two-class classifier built on the ith class and all the remaining classes. The ith decision function for the ith classifier and the remaining classes has the form ( ) ( ) ( ) Hyper-plane yi(x) = 0 will form optimal division hyperplane, the support vector of class (i) puts yi(x) = 1 and the remaining support vector class to be satisfying yi(x) = -1. - Binary_tokens[i]= -1 corresponds to the ith element which is a sign of text. Tokens[] is an array of elements including value of text signs or tags corresponding to elements in the binary_tokens[]. Example, at position 23, binary_tokens [23] = 1, tokens [23] = <td…>. Merge adjacent elements which have the same value in the binary_tokens[] array to make an element in 128 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org If the data vector x satisfying the conditions yi(x) > 0 for only one i, x will be assigned to the ith class. But the number of training record for each classifier in OAO is less than OAR and the classification is also simpler. So the OAO strategy has higher accuracy, but the cost to build is equivalent to OAR strategy. The decision function to subclass of class i to class j in the OAO strategy is: ( ) ( ) ( ) However, both strategies lead to a vague region in the classification (Fig 3). We can avoid this problem by building K-Class based on K-linear functions of the form: ( ) ( ) And a point s is assigned to the class Ck if: ( ) ( ) with every . Technology, Education, Business, Sports Classifier -1 1 Technology Education, Sports Business, Classifier -1 1 Education Business, Sports Classifier -1 1 Business Sports Fig 1: OAR Strategy OAO strategy (Fig 2) uses K* (K-1)/2 binary classifiers constructed by pairing two classes so this strategy should also be referred to as the pair (pairwise) and used the following the method of combining multiple parts of this class to determine the final classification results. The number of classifiers never exceeds K*(K-1)/2 Technology Education Tech-Edu Classifier Technology Business Tech-Bus Classifier Technology Sports Tech-Spo Classifier Education Business Bus-Edu Classifier Education Sports Edu-Spo Classifier Business Sports Bus-Spo Classifier Fig 3: The vague region in subclass Table 2. Category label of each topic Topic Label Technology 1 Education 2 Business 3 Laws 4 Sports 5 The specific steps in the training phase as the following Step 1: Download the HTML page corresponding to the news page links to filter and retrieve content saved in plain text format (file.txt), remove the documents which are over the size allowed (1KB) and have duplicate contents. Step 2: Separate words (integrate VnTokenize) according to [20] and remove the stop words, select features [4] (the selection of features will be presented in detail in section 4) Step 3: Represent a news article as a vector as follows: <classi ><label1>:<value1><label2>:<value2> ... <labeln>:<valuen> Where: - Classi is the category label of each topic with i = 1 5 (Table 2). Fig 2: OAO Strategy Compared with OAR strategy, the advantage of the strategy is not only to reduce the region which cannot be classified, but also to increase the accuracy of the classification. The strategy OAR just needs K-1 classifiers meanwhile the OAO strategy needs K*(K-1)/2 classifiers. 129 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org - - Labelj is the index of the jth feature word in the feature space which may appear in the training news with j = 1 n. Valuej is the weight of the indexj which is calculated by the TF.IDF formula, if the valuej = 0, then do not write that feature itself. This format complies to the input data format of the program SVMMulticlass [21]. choose n dimensions corresponding to n words with the highest weights. Representation of all news articles described in step 3, Section 3.2 in which: Valuei of the ith word in vector representing jth news is the weight of the word which is calculated by the formula (4) ( Step 4: Train classification model based on multi-class SVM algorithm applying OAO strategy with the optimal model parameters (by experiment and using a number of methods such as GrisSeach, Genetics) The specific steps in the classifying phase as the following: Step 1: Allow the user to select seed words then generate queries randomly. Step 2: Perform a search for each query through Google and store links of the found news site after filtering out invalid links such as: music, video, and forums… Step 3: Use the method of [1] to extract text from the download link, check and remove the text files which do not meet requirement (size<1KB) and text files having duplicate content. Step 4: Perform to separate words (integrated VnTokenize) and remove stop words from the text. Represent the text as feature vector which is input format of the SVM algorithm. Step 5: Perform classification (under 5 labels), and save the results in a database. 4. Experiments and Evaluation 4.1. Pre-processing data and experiments on classification model training Training and testing data were built semi-automatically by the authors. We have developed software to automatically extract content of the text by updating the RSS links of two news electronic sites that are VietNamnet.net and Vnexpress.net by date for each topic (Technology, Education, Business, Laws, Sport). The data obtained is the links of news sites after removing duplicate links, invalid links. The content of news sites are extracted based on the method described in [1]. Then, the preprocessing steps of separating and removing the stop words made as step 2 in the training phase presented in section 3.2. After separating of words, the words will be re-weighted to carry out the selection of features vector for articles. Each article in the data set will be represented by an n-dimensional vectors, each dimension corresponds to a feature word. We ) { ( ( )) [ ] ( ) Where: ∑ tfij (Term frequency): The number of occurrences of the word wi in document dj dfi (Document frequency): The number of documents that contain the word wi cfi (Collection frequency): The number of occurrences of word wi in the corpus. If Valuei = 0, do not need to keep this feature. The data set for the training and testing phases includes 2114 articles in total in which 1000 articles belong to the training data set and all remaining 1114 the testing belong to data set. Table 3 lists the number of the training data set and testing on each topic. Table 3. Number of training data set and testing Topic Training data set Test data set Technology 200 123 Education 200 128 Business 200 236 Sports 200 62 Laws 200 565 To choose the value for the dimension of feature vectors, we perform experiments with different values of n listed in Table 4. Evaluation results of SVM and Bayes classifier with different dimensions of feature vectors on the same set of training and testing data set are shown in Table 3 with the accuracy suitable evaluated by the formula (5) and (6). This is the basis for selecting the dimension of the feature space for classifiers: The given criteria evaluating on is the high classification results and narrow fluctuations in a certain data region. Based on Table 4, authors choose dimension n for SVM method is 2000 and Bayes method is 1500. ( ) Where: 130 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org - Pre: Classification accuracy for a topic. - TD: The number of correctly classified documents. - SD: Total number of documents to be classified. in Table 5 according to the formula (5) and (6). Results of classification for the accuracy of each topic are different. Technology topics have the lowest accuracy and Sports have the highest accuracy. ( ) Table 5. Results of evaluations are categorized by topic Where: - Tpre: Total classification accuracy for topics. - TDCi: The number of correctly clssified documents belonging to the topic Ci. - SDCi: Total number of classified documents belonging to the topic Ci. - ST: Total topics. Topic Number of news NB Method sites Technology Education Business Laws Sports 123 128 236 62 565 SVM Method 77.23% 92.96% 94.91% 83.87% 94.51% 87% 96.88% 83.47% 96.77% 98.58% 4.2 Classification experiment and evaluation 5. Conclusion In order to automatically classify information on the web, the authors build applications which automatically classify 5 topics: Technology, Education, Laws, Business and Sports. This classification models are trained with SVM and Bayes algorithms with the dimension of the feature vectors selected in Section 4.1. The application is built following 5 specific steps in the classification phase presented in Section 3.2. To evaluate the classification model obtained after conducting the training, we tested classified documents of 1114 in different categories. This paper describes automatically classifying framework for Vietnamese news from news sites on the Internet. In the proposed method, the contents of Vietnamese news are extracted automatically by applying the improved performance extraction of the author group [1]. The news is classified by using two machine learning methods Naïve Bayes and SVM. Experiments on news sites (vietnamnet.vn and vnexpress.net) shows that using SVM method gives a higher (94%) accuracy while the method naïve Bayesian network for lower results. However, we find that classification accuracy is different with various topics and Sports news has the highest accuracy. In future, we will aim to improve automatic classification methods to increase classification accuracy for different news topics and extend widen the types of sites with different and more complicated content than news. Table 4. Results of evaluation with the different lengths of vectors Number of dimensions of feature vectors Accuracy of SVM algorithm Accuracy of Naïve Bayes algorithm 500 91.56% 89.77% 800 91.92% 90.04% 1000 92.01% 90.39% 1200 92.37% 90.57% 1500 93.00% 91.92% 1800 93.63% 90.48% 2000 93.81% 90.84% 2500 93.72% 90.79% Acknowledgments We would like thank to Phuong le Hong PhD providing useful tools for word processing on the Web Vietnamese. References [1] Phan Thi Ha and Ha Hai Nam, “Automatic main text extraction from web pages”, Journal of Science and Technology, Vietnam, Vol. 51, No.1, 2013. [2] Yang and Xin Liu, “A re-examination of text categorization methods”, Proceedings of ACM SIGIR Conference on Research and Development in Information Retrieval (SIGIR’99), 1999. [3] Rong Hu, “Active Learning for Text Classification”, Ph.D Thesis, Dublin Institute of Technology, Dublin, Ireland, 2011. [4] Joachims T., “Text categorization with Support Vector Machines: Learning with many relevant features”, in Proc. of the European Conference on Machine Learning (ECML), 1998, pages 137–142. The results showed that the SVM method give results with an accuracy of approximately 94%, Naïve Bayes (NB) method with an accuracy of approximately 91%. The accuracies are calculated by the formula (5) and (6). For each topic, testing data and evaluation results are described 131 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [5] Fabrizio Sebastiani, “Text categorization”, In Alessandro Zanasi (ed.), Text Mining and its Applications, WIT Press, Southampton, UK, 2005, pp. 109-129. First Author: Dr. Phan Thi Ha is currently a lecturer of the Faculty of Information Technology at Posts and Telecommunications Institute of Technology in Vietnam. She received a B.Sc.in Math & Informatics, a M.Sc. in Mathematic Guarantee for Computer Systems and a PhD. in Information Systems in 1994, 2000 and 2013, respectively. Her research interests include machine learning, natural language processing and mathematics applications. [6] Tong Zhang and Frank J. Oles. “Text categorization based on regularized linear classification methods”, Information Retrieval, Vol. 4:5-31, 2001 [7] Tran Vu Pham, Le Nguyen Thach, “Social-Aware Document Similarity Computation for Recommender Systems”, in Proceedings of the 2011 IEEE Ninth International Conference on Dependable, Autonomic and Secure Computing, 2011, Pages 872-878 Second Author: M.Sc Nguyen Quynh Chi is currently a lecturer of the Faculty of Information Technology at Posts and Telecommunications Institute of Technology in Vietnam. She received a B.Sc.in Information Technology in Hanoi University of Technology in Vietnam, a M.Sc. in Computer Science in University of California, Davis, USA (UCD) and became PH.D Candidate at UCD in 1999, 2004 and 2006, respectively. Her research interests include machine learning, data mining. [8] Tran Vu Pham, “Dynamic Profile Representation and Matching in Distributed Scientific Networks”, Journal of Science and Technology Development, Vol. 14, No. K2, 2011 [9] David Gibson, Kunal Punera, Andrew Tomkins, “The Volume and Evolution of Web Page Templates”. In WWW\'05: Special interest tracks and posters of the 14th international conference on World Wide Web, 2005. [10] Aidan Finn, Nicholas Kushmerick, Barry Smyth, “Fact or Fiction: Content Classification for Digital Libraries”, Proceedings of the Second DELOS Network of Excellence Workshop on Personalisation and Recommender Systems in Digital Libraries, Dublin City University, Ireland, 2001. [11] Aidan. Fin, R. Rahman, H. Alam and R. Hartono, “Content Extraction from HTML Documents”, in WDA: Workshop on Web Document Analysis, Seattle, USA, 2001. [12] C.N. Ziegler and M. Skubacz, “Content extraction from news pages using particle swarm optimization on linguistic and structural features,” in WI ’07: Proceedings of the IEEE/WIC/ACM International Conference on Web Intelligence. Washington, DC, USA: IEEE Computer Society, 2007, pp. 242–249. [13] Ion Muslea, Steve Minton, and Craig Knoblock, “A hierarchical Approach to Wrapper Induction”, in Proceedings of the third annual conference on Autonomous Agents, 1999, Pages 190-197. [14] Tim Weninger, William H. Hsu, Jiawei Han, “CETR-Content Extraction via Tag Ratios”. In Proceedings of the 19th international conference on World wide web, 2010, Pages 971-980 [15] Sandip Debnath, Prasenjit Mitra, Nirmal Pal, C. Lee Giles, “Automatic Identification of Informative Sections of Web-pages”, Journal IEEE Transactions on Knowledge and Data Engineering, Vol. 17, No. 9, 2005, pages 1233-1246 [16] http://nhuthuan.blogspot.com/2006/11/s-lc-v-k-thut-trong-vietspider3.html [17] www.majestic12.co.uk/projects/html_parser.php [18] Vu Thanh Nguyen, Trang Nhat Quang, “ Ứng dụng thuật toán phân lớp rút trích thông tin văn bản FVM trên Internet”, Journal of Science and Technology Development,Vol. 12, No. 05, 2009. [19] Ngo Quoc Hung, “Tìm kiếm tự động văn bản song ngữ Anh-Việt từ Internet”, MS thesis, Ho Chi Minh City University of Science, Vietnam, 2008 [20] http://mim.hus.vnu.edu.vn/phuonglh/softwares/vnTokenizer [21] http://www.cs.cornell.edu/people/tj/svm_light/svm_multiclass.html [22] http://mason.gmu.edu/~montecin/htmltags.htm#htmlformat [23] http://www.w3schools.com/tags/ 132 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org Practical applications of spiking neural network in information processing and learning Fariborz Khademian1, Reza Khanbabaie2 1 Physics Department, Babol Noshirvani University of Technology, Babol, Iran [email protected] 2 Physics Department, Babol Noshirvani University of Technology, Babol, Iran [email protected] Abstract Historically, much of the research effort to contemplate the neural mechanisms involved in information processing in the brain has been spent with neuronal circuits and synaptic organization, basically neglecting the electrophysiological properties of the neurons. In this paper we present instances of a practical application using spiking neurons and temporal coding to process information, building a spiking neural network – SNN to perform a clustering task. The input is encoded by means of receptive fields. The delay and weight adaptation uses a multiple synapse approach. Dividing each synapse into sub-synapses, each one with a different fixed delay. The delay selection is then performed by a Hebbian reinforcement learning algorithm, also keeping resemblance with biological neural networks. Keywords: Information processing, Spiking neural network, Learning. Fig.1 simple temporal encoding scheme for two analog variables: x1=3.5 and x2=7.0, with x3 as the reference, firing always at 0 in a coding interval of 10ms. A very simple temporal coding method, suggested in [13], [14], is to code an analog variable directly in a finite time interval. For example, we can code values varying from 0 to 20 simply by choosing an interval of 10ms and converting the analog values directly in proportional delays inside this interval, so that an analog value of 9.0 would correspond to a delay of 4.5ms. In this case, the analog value is encoded in the time interval between two or more spikes, and a neuron with a fixed firing time is needed to serve as a reference. Fig. 1 shows the output of three spiking neurons used to encode two analog variables. Without the reference neuron, the values 3.5 and 7.0 would be equal to the values 6.0 and 2.5, since both sets have the same inter-spike interval. If we now fully connect these three input neurons to two output neurons, we will have a SNN like the one shown in fig.2, which is capable of correctly separating the two clusters shown in the right side of the figure. Although this is a very simple example, it is quite useful to illustrate how real spiking neurons possibly work. The clustering here was made using only between the input and output the axonal delays neurons with all the weights equal to one. 1. Information Encoding When we are dealing with spiking neurons, the first question is how neurons encode information in their spike trains, since we are especially interested in a method to translate an analog value into spikes [1], so we can process this information in a SNN. This fundamental issue in neurophysiology remains still not completely solved and is extensively paid for in several publications [2], [3], [4], [5]. Although a line dividing the various coding schemes cannot always be clearly drawn [6], it is possible to distinguish essentially three different approaches [7], [8], in a very rough categorization: 1. rate coding: the information is encoded in the firing rate of the neurons [9]. 2. temporal coding: the information is encoded by the timing of the spikes. [10] 3. population coding: information is encoded by the activity of different pools (populations) of neurons, where a neuron may participate of several pools [11], [12]. 133 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org In a SNN with input and output neuron, the center of the RBF-like1 output neuron is given by the vector , where { | } . Similarly, the input vectors are defined as , where and is the firing time of each input neuron [10]. The SNN used here has an EPSP2 with a time constant and threshold . The lateral connection between the two output neurons is strongly inhibitory. Figure. 3 Continuous input variable encoded by means of local receptive fields. From a biological point of view, we can think of the input neurons as if they were some sort of sensory system sending signals proportional to their excitation, defined by the Gaussian receptive fields. These neurons translate the sensory signals into delayed spikes and send them forward to the output neurons. In this work, the encoding was made with the analog variables normalized in the interval [0,1] and the receptive fields equally distributed, with the centers of the first and the last receptive fields laying outside the coding interval [0,1], as shown in fig. 3, there is another way to encode analog variables, very similar to the first, the only difference being that no center lays outside the coding interval and the width of the receptive fields is broader. Fig.2 Left: SNN with a bi-dimensional input formed by three spiking neurons and two RBF-like output neurons. Right: two randomly generated clusters (crosses and circles), correctly separated by the SNN. This encoding method can work perfectly well for a number of clusters less or equal to the number of dimensions, but its performance decreases when the number of clusters exceeds the number of input dimensions. The proposed solution for this problem [15] implemented here uses an encoding method based on population coding [16], which distributes an input variable over multiple input neurons. By this method, the input variables are encoded with graded and overlapping activation functions, modeled as local receptive fields. Fig. 3 shows the encoding of the value 0.3. In this case, assuming that the time unit is millisecond, the value 0.3 was encoded with six neurons by delaying the firing of neurons 1 (5.564ms), 2 (1.287ms), 3 (0.250ms), 4 (3.783ms) and 5 (7.741ms). Neuron 6 does not fire at all, since the delay is above 9ms and lays in the no firing zone. It is easy to see that values close to 0.3 will cause neurons 2 and 3 to fire earlier than the others, meaning that the better a neuron is stimulated, the nearer to ms it will fire. A value up to ms is assigned to the less stimulated neurons, and above this limit the neuron does not fire at all (see fig. 4). Fig. 4 Spikes generated by the encoding scheme of the first type shown in figure 3. 1 2 Both types of encoding can be simultaneously used, like in fig. 5, to enhance the range of detectable detail and provide multi-scale sensitivity [17]. The width and the Radial Basis Function network Excitatory postsynaptic potential 134 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org centers are defined by Eq. (1) and (2), for the first and second types, respectively. Unless otherwise mentioned, the value of used for the first type is 1.5 and 0.5 for the second. Fig. 6 The SNN at left was capable of correctly separate ten clusters. The lateral connections linking the output neurons are strong inhibitory synapses, disabling all other neurons to fire after the first neuron has fired, thus implementing the winner-takes-all process. Each dimension of the input was coded by a receptive field with 12 neurons. ( ) The learning function used here shown in fig. 6, is a Gaussian curve defined by the Eq. (4) [23]. It reinforces the synapse between neurons and , if , and depresses the synapse if . Where we have the parameter in this form. Fig. 5 Two ways to encode continuous input variable by means of local receptive fields. The dotted lines are wide receptive fields of the second type, with 𝜆 2. Learning Giving some background information and instances of the application of the models to simulate real neurons, these examples demonstrate the existence of a relationship between electrophysiology, bifurcations, and computational properties of neurons, showing also the foundations of the dynamical behavior of neural systems. The approach presented here implements the Hebbian reinforcement learning method [18] through a winnertakes-all algorithm [19], that its practical application in SNN is discussed in [20] and a more theoretical approach is presented in [21]. In a clustering task, the learning process consists mainly of adapting the time delays, so that each output neuron represents an RBF center. This purpose is achieved using a learning window or learning function [22], which is defined as a function of the time interval between the firing times and . This function controls the learning process by updating the weights based on this time difference, as shown in Eq. (3), where is the amount by which the weights are increased or decreased and is the learning rate. Fig. 7 Gaussian learning function, with 𝛼 𝛽 𝑎𝑛𝑑 𝑣 The learning window is defined by the following parameters: - : this parameter, called here neighborhood, determines the width of the learning window where it crosses the zero line and affects the range of , inside which the weights 135 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [4] Araki, Osamu, and Kazuyuki Aihara. "Dual coding in a network of spiking neurons: aperiodic spikes and stable firing rates." Neural Networks, 1999. IJCNN'99. International Joint Conference on. Vol. 1. IEEE, 1999. [5] Koch, Christof. Biophysics of computation: information processing in single neurons. Oxford university press, 1998. [6] Dayan, P. E. T. E. R., L. F. Abbott, and L. Abbott. "Theoretical neuroscience: computational and mathematical modeling of neural systems." Philosophical Psychology (2001): 563-577. [7] Maass, Wolfgang, and Christopher M. Bishop. Pulsed neural networks. MIT press, 2001. [8] Gerstner, Wulfram, and Werner M. Kistler. Spiking neuron models: Single neurons, populations, plasticity. Cambridge university press, 2002. [9] Wilson, Hugh Reid. Spikes, decisions, and actions: the dynamical foundations of neuroscience. Oxford University Press, 1999. [10] Ruf, Berthold. Computing and learning with spiking neurons: theory and simulations. na, 1998. [11] Snippe, Herman P. "Parameter extraction from population codes: A critical assessment." Neural Computation 8.3 (1996): 511-529. [12] Gerstner, Wulfram. "Rapid signal transmission by populations of spiking neurons." IEE Conference Publication. Vol. 1. London; Institution of Electrical Engineers; 1999, 1999. [13] Hopfield, John J. "Pattern recognition computation using action potential timing for stimulus representation." Nature 376.6535 (1995): 33-36. [14] Maass, Wolfgang. "Networks of spiking neurons: the third generation of neural network models." Neural networks 10.9 (1997): 1659-1671. [15] Avalos, Diego, and Fernando Ramirez. "An Introduction to Using Spiking Neural Networks for Traffic Sign Recognition." Sistemas Inteligentes: Reportes Finales EneMay 2014} (2014): 41. [16] de Kamps, Marc, and Frank van der Velde. "From artificial neural networks to spiking neuron populations and back again." Neural Networks 14.6 (2001): 941-953. [17] Avalos, Diego, and Fernando Ramirez. "An Introduction to Using Spiking Neural Networks for Traffic Sign Recognition." Sistemas Inteligentes: Reportes Finales EneMay 2014} (2014): 41. [18] Morris, R. G. M. "DO Hebb: The Organization of Behavior, Wiley: New York; 1949." Brain research bulletin 50.5 (1999): 437. [19] Haykin, Simon. "Adaptive filters." Signal Processing Magazine 6 (1999). [20] Bohte, Sander M., Han La Poutré, and Joost N. Kok. "Unsupervised clustering with spiking neurons by sparse temporal coding and multilayer RBF networks."Neural Networks, IEEE Transactions on 13.2 (2002): 426-435. [21] Gerstner, Wulfram, and Werner M. Kistler. "Mathematical formulations of Hebbian learning." Biological cybernetics 87.5-6 (2002): 404-415. [22] Kempter, Richard, Wulfram Gerstner, and J. Leo Van Hemmen. "Hebbian learning and spiking neurons." Physical Review E 59.4 (1999): 4498. are increased. Inside the neighborhood the weights are increased, otherwise they are decreased. - : this parameter determines the amount by which the weights will be reduced and corresponds to the part of the curve laying outside the neighborhood and bellow the zero line. - : because of the time constant of the EPSP, a neuron firing exactly with does not contribute to the firing of , so the learning window must be shifted slightly to consider this time interval and to avoid reinforcing synapses that do not stimulate . Since the objective of the learning process is to approximate the firing times of all the neurons related to the same cluster, it is quite clear that a neuron less stimulated (large and thus, low weight) must have also a lower time constant, so it can fire faster and compensate for the large . Similarly, a more stimulated neuron (small and thus, high weight) must have also a higher time constant, so it can fire slower and compensate for the small . 3. Conclusions All the experimental results obtained in the development indicate that the simultaneous adaptation of weights and time constants (or axonal delays) must be submitted to a far more extensive theoretical analysis. Given the high complexity of the problem, it is not encompassed by the scope of the present work, and hence should be left to a further work. It was presented a practical applications of a neural network, built with more biologically inspired neuron, to perform what we could call real neuroscience task. In this application we demonstrated how analog values can be temporally encoded and how a network can learn using this temporal code. Even with these very short steps towards the realm of neuroscience, it is not difficult to realize how intricate things can get, if we try to descend deeper into the details of neural simulation. However, this apparent difficulty should rather be regarded as an opportunity to use spike-timing as an additional variable in the information processing by neural networks [24]. References [1] Hernandez, Gerardina, Paul Munro, and Jonathan Rubin. "Mapping from the spike domain to the rate-based domain." Neural Information Processing, 2002. ICONIP'02. Proceedings of the 9th International Conference on. Vol. 4. IEEE, 2002. [2] Aihara, Kazuyuki, and Isao Tokuda. "Possible neural coding with interevent intervals of synchronous firing." Physical Review E 66.2 (2002): 026212. [3] Yoshioka, Masahiko, and Masatoshi Shiino. "Pattern coding based on firing times in a network of spiking neurons." Neural Networks, 1999. IJCNN'99. International Joint Conference on. Vol. 1. IEEE, 1999. 136 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved. ACSIJ Advances in Computer Science: an International Journal, Vol. 4, Issue 4, No.16 , July 2015 ISSN : 2322-5157 www.ACSIJ.org [23] Leibold, Christian, and J. Leo van Hemmen. "Temporal receptive fields, spikes, and Hebbian delay selection." Neural Networks 14.6 (2001): 805-813. [24] Bohte, Sander M. "The evidence for neural information processing with precise spike-times: A survey." Natural Computing 3.2 (2004): 195-206. First Author Master of science in neurophysics at Noshirvani Institute of Technology; analyzing visual information transmission in a network of neurons with feedback loop. Second Author Post-doctoral at University of Ottawa, Canada; Synaptic Plasticity, Dynamic Synapses, Signal Processing in Electric Fish Brian. PhD at Washington University in St.Louis, USA; Synaptic Plasticity, Dynamic Synapses, Signal processing in Birds Brain. 137 Copyright (c) 2015 Advances in Computer Science: an International Journal. All Rights Reserved.