The 9 Interdisciplinary Research Conference ORT Braude College

Transcription

The 9th Interdisciplinary Research Conference
ORT Braude College
Book of Abstracts
October 2-3, 2013
HaGoshrim Hotel, Upper Galilee
ISBN 978-965-91208-8-8
Abstracts
Department
Pages
Interdisciplinary……………………………………………………..….…
1–7
Biotechnology Engineering…………………………………………...…..
8 - 16
Electrical and Electronic Engineering………………………………..….
17 - 22
Industrial Engineering and Management……………………..….…......
23 – 31
Mathematics………………………………………………….………..…..
32 – 40
Mechanical Engineering……………………………………….……..…..
41 – 48
Physics and Optical Engineering…………………………..…….…..…..
49 – 55
Software Engineering…………………………………….…………........
56 – 62
Teaching and Learning…………………………………….………..……
63 – 71
Author Index…………………………………………………………...….
72
Note: The author whose name appears in bold print in each abstract is the presenting author.
The 9th ORT Braude Interdisciplinary Research Conference
Interdisciplinary  1
Assessment of the mobility and fate of natural and naturally modified
engineered nano-particles related to in-situ remediation of soil and
groundwater contamination
Isam Sabbah1, Yuri Haimov1
1
Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901786, E-mail: [email protected]
Keywords: humic substances, engineered nano-particles, transport, breakthrough curve, retardation
This research tries to assess the mobility, transport, and fate of natural and naturally-modified
engineered NPs with respect to in-situ remediation of groundwater contaminants. This work is
motivated by the burgeoning growth of appropriate solutions to cleanup groundwater using
nanomaterials. Efficient, robust, safe, passive, cost-effective, sustainable, and green remediation
approaches are required. And to ensure working with, rather than against, nature, the focus of recent
research is on natural nanoparticles (NPs), which are NPs modified using natural humic substance (HS)
coatings to produce bespoke hybrid NPs.
Column experiments with sand, glass bead porous media, and sandy loam soil from the Bet Dagan
region (Hamra) identified the mechanisms of transport and fate of NPs and surface modified NPs with
humic substances as either coating matrix or mobile liquid. Copper oxide and titanium oxide
represented engineered nanoparticles.
Several experiments accounted for the breakthrough of three humic material sources in the studied
porous media. By comparing the breakthrough curves (BTCs) of humic materials to that of a nonsorbing tracer in the sand and glass bead columns, it was shown that the BTCs of the tracer and the two
humic materials were very similar, indicating that sorption and retardation of both are insignificant.
However, when applying the same procedure in a column of real (hamra) soil, the transport of humic
substances was very limited, showing a high retardation factor. Also, we obtained data showing that the
source of the humics as well as the extraction method can significantly affect the mobility of humics
through the real soil.
As for the nano copper oxide and nano titanium oxides, the breakthrough experiments show that these
nanoparticles are not stable and an aggregation very rapidly occur seven when using sand and glass
beads as porous media. However, using dissolved humic substances, the transport of the engineered
nanoparticle was enhanced, showing almost no retardation.
These preliminary findings suggest that the transport of engineered and natural NPs (i.e.,CuO, TiO2,and
HS) is not obvious and smooth, which requires more basic investigation for better understanding of their
transport and fate. In addition, more comprehensive experimental as well as modeling studies are
needed to account for these natural particles as a remedial agent, a surface modifier for engineered NPs,
and an environmentally existing compound that may affect the transport and fate of engineered NPs,
hence affecting the in-situ remediation.
2  Interdisciplinary
Toward computational design of efficient plasticizers for nylon
David Alperstein1, Dafna Knani2
1
Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901944, Fax: 972-4-9901886, E-mail: [email protected]
2
Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901875, Fax: 972-4-9901839, E-mail: [email protected]
Keywords: nylon, plasticizers, molecular modeling, computational design
Polyamides are semi-crystalline polymers useful in a wide range of applications in the plastics industry.
Some applications require higher flexibility and workability of the polyamides. Therefore, plasticizers
are added to ease compounding and processing procedures and produce the desired product properties.
Previously, we performed computational work to determine plasticizer efficiency for the nylon 66/6
copolymer. Four plasticizers were examined and graded according to several calculated properties.
According to these factors, Methyl 4-hydroxybenzoate (M4HB) is the most efficient plasticizer.
This finding correlates well with the experimental results, based on reduction of the polymer glass
transition temperature (Tg). The highest calculated plasticization efficiency was obtained for M4HB, for
which the decrease in Tg was the most significant [1].
The goal of the present study was to use computational tools to estimate plasticizer efficiency in
plasticizing nylon 66/6. It is known that plasticizer efficiency is greatly influenced by structural effects
of the plasticizer and the nature of the polymer, and therefore in this research a systematic study was
conducted to explore those factors.
An homology series of esters of 4-Hydroxybenzoate with various chain lengths of the alcohol moiety
was examined. Also, the efficiency of linear plasticizers was compared to branched ones and
stereoisomers were considered. Plasticizer efficiency was determined by calculating cohesive energy
density (CED), solubility parameters, free volume, and interaction intensities of pristine nylon and the
nylon–plasticizer blends.
It was found that plasticizer efficiency of esters with linear alcohol moiety is higher than branched
chains. Whereas plasticizer efficiency increases when the branched side chain is more bulky, no
coherent trend was observed for the linear side chain of the alcohol moiety. Surprisingly, a significant
difference was observed between the pair of enantiomers. The most efficient plasticizer of the eight
examined was the chiral molecule (R)-2-Methylbutyl-4-Hydroxybenzoate (R-MB4HB), increasing the
free volume of the nylon 60-fold (three-fold greater than the original Methyl 4-Hydroxybenzoate
(M4HB)).
A good correlation was found between the various calculated factors. The most efficient plasticizer is
the one that exerts the highest free volume enlargement, having the largest heat of mixing, and the
strongest interactions with the polymer.
[1] D. Alperstein, D. Knani, A Goichman, and M. Narkis, "Determination of plasticizer efficiency for
nylon by molecular modeling", Polymer Bulletin, 68, (2012), 1977-1988
Biomimetic locust-like jumping robot
Valentin Zaytsev1, Uri Ben-Hanan1, Avi Weiss1, Gabor Kosa2, and Amir Ayali3
1
2
Faculty of Mechanical Engineering, Tel Aviv University
3
Department of Zoology, Faculty of Life Sciences, Tel Aviv University
Keywords: locust, jumping, biomimetic robot
Locust jumping includes two phases: first, slow charging of elastic elements in the leg joints due to
chemical energy conversion in the leg muscles; and second, quick energy release from elastic elements
to the legs structure, which converts to kinetic energy, causing the leap.
The aim is to mimic the jumping principles of the locust to obtain efficient locomotion and payload
transference.
We developed a 25-gram robot that jumps to a height of 2.5 meters. The robot mimics the jumping
principles of the locust. The robot converts electrical energy to mechanical energy with a small battery
and a motor, and utilizes the energy for the leap. In the charging phase the motor rotates to one side, and
a wire connected to the legs winds on a roller mounted on the motor shaft, causing the two leg segments
to approach and deforming the elastic joints that store the energy. Later, in the leap phase, the motor
rotates quickly to the other side, releasing the wire faster than the elastic joint while the stored energy
converts to the kinetic energy of the leap.
Mathematical and physical analysis and simulations were made for the leap phase and the flight phase.
It was determined that the energy required for the leap is 1Joule, allowing a take-off velocity of 8.6 m/s.
The innovation of the robot is its use of a direct charge without a cam mechanism or gears, due to a
lever ratio between the motor shaft and the legs.
The first prototype is currently being built to be tested and evaluated and then optimized. After
evaluating the results, a second prototype will be built.
Acknowledgement: This study was supported by a grant from the Pearls-Of-Wisdom conference.
Analysis of thermo-electromechanical buckling of micro annular plate
Samy Abu-Salih
Keywords: thermo-electromechanical buckling, micro annular plate
This work presents the analysis of critical thermo electromechanical buckling (TEMB) of a micro elastic
and isotropic annular plate that is simultaneously subjected to a thermal load and symmetric electrostatic
force. The annular plate is assumed to be rigidly clamped at its outer radius edge and free at the inner
radius edge. TEMB is the bifurcation response that results from the coupling of electromechanical
bifurcation and thermo-mechanical buckling. It will be shown that the TEMB state depends on the
values of two different loading parameters. The capability to determine the values of the critical
buckling temperature or the critical buckling voltage enables us to instigate buckling even when the inplane thermal stresses are in tension. The most interesting result that will be shown is that TEMB allows
us to determine the number of buckled elastic flexures along the circumference of the annular plate. In
other words, TEMB of annular plate permits manipulation of the critical buckling values and the shape
mode of the buckling response. Finally, it will be shown for the first time that symmetric electrostatic
forces can be modeled as an active “virtual” elastic foundation with a stiffness that can be manipulated
to achieve the desired thermo-electro-mechanical response.
Analysis of huge volume of Orange cellular data
Thomas Couronné1, Valery Kirzner2, Katerina Korenblat3, Zeev Volkovich4
1
Orange Labs - France Telecom R&D, Paris, France, E-mail: [email protected]
Institute of Evolution, University of Haifa, Israel, Tel: 972-4-8240449, Fax: 972-4-2460554,
E-mail: [email protected]
3
Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901845,
Fax: 972-4-9901852, E-mail: [email protected]
4
Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901764,
2
Keywords: mobile phone data, human behavior learning, sparse data
Human mobility analysis is an important issue in social sciences, and mobility data are among the most
sought-after sources of information in urban studies, geography, transportation, and territory
management. So, recognizing and classifying users’ routine behavior patterns is a hot topic, aiming to
discover automatically recurrent routine patterns in a user’s daily life by leveraging the data extracted
from mobile phones. Most work in this area relies on densely sampled mobile data collected from
specially programmed sensors that can “follow” people.
In this talk we consider the problem of discovering humans’ personal behavior routines from large-scale
sparse mobile phone data aiming to provide informative user profile contexts to enable various humancentered applications. Two new methodologies to uncover humans’ routine behaviors are offered by
statistically correlating the temporal features in the mobile data.
We present two new methods to the analysis of big sparse cellular data. The first approach is based on a
bi-clustering technique where features and items are simultaneously clustered. Primarily the hours
within a day (the features) are clustered, aiming to group customer information according to the
obtained hours' partition. Such restructured data allows offering a sufficiently robust clustering of
customers, and moreover, to provide a cluster description in terms of calls, in particular time intervals.
To compare distributions of calls in hours we use the Kolmogorov-Smirnov distance. Based on the hour
partition, the data are captured in a more compact and informative manner. At the next stage the crossentropy method is applied to categorize the customers.
The second approach is based on a linguistic representation of customer activity as a string on a fourletter alphabet. Routine behavior is characterized in this way, revealing a connection to the well-known
physics and social sciences fundamental laws like the Maxwell–Boltzmann distribution.
We use a real-world mobile phone data set to validate our approaches. In evaluation, we show that our
methods can capture strong behavior patterns from sparse mobile data by analysis of information
concerning customers falling in certain clusters, admitting suitable social interpretations.
The proposed novel methods provide new behavior models and demonstrate high abilities in handling
human mobility analysis.
Engineering education: present and future
Alec Groysman
Department of Mechanical Engineering and Prof. Ephraim Katzir Department of Biotechnology Engineering,
ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, E-mail: [email protected]
Keywords: engineering education, humanitarian aspects, interdisciplinary communication.
What will be in shortage in the near future? Skilled knowledgeable specialists! There is a need for
knowledge transfer. One can see the aging of the workforce in any country. The number of elderly
experts above the age of 60 is increasing while the influx of young people (at the age of 25-30) who are
yet to become experts is decreasing. Young people are less interested in studying technical subjects.
What is the place of the engineer in our society? Who is an engineer today? How should tomorrow’s
engineers look? Should they know sciences as well as humanitarian disciplines? What is the place of
scientific and humanitarian disciplines in engineering education? How can engineers use art, history,
and philosophy for inspiration and creativity? We need to explain how humanitarian aspects can be used
in engineering education. There is mutual influence between humanitarian disciplines and engineering.
This talk discusses interdisciplinary and humanitarian thinking of engineers.
The aim of this work is to show how humanitarian aspects and interdisciplinary communication can
help in engineering education. The philosophy of my work is establishing interrelationships between
humanitarian aspects, engineering, and science—studying new inspirations and creativity in
engineering—to show the young generation of engineers and educators how learning, education, and our
very existence can be interesting, fascinating, creative, productive, exciting, attractive, rich, and, as a
result, beautiful.
Examples of using different humanitarian disciplines (art: music, painting, literature, poetry, sculpture;
history; philosophy) in curricula of materials science and engineering, chemical thermodynamics, and
corrosion of metals are shown. Interdisciplinary communication between exact sciences as well between
engineering and humanitarian disciplines were used. Analogies, interrelations, metaphors, comparison,
logics and intuition, common aspects and differences between humanitarian and engineering disciplines
are used in engineering education for the second and fourth year students. Their understanding is
compared with students and engineers who did not receive such education.
Students and young engineers who received explanations of engineering disciplines in interaction and
communication with humanitarian aspects showed more creativity and satisfaction in their job, progress,
further studying, and life. They have another approach to comprehending apprehending engineering
disciplines and their very existence, which is now seems beautiful.
Humanitarian aspects and interdisciplinary communication should be widely included in engineering
education; in other words, we can talk about “beautifying” engineering. Learning and education of
students and educators using humanities disciplines results in greater attractiveness of engineering, and
adds to the beauty, inspiration, and creativity of the young generation of engineers. We should strive to
educate towards the polyfunctional, diversified, and multiform cultural engineer.
From “TEMPUS - English for All” to “ERASMUS for All”
Linda Weinberg
English Studies Unit, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901985, E-mail:
[email protected]
Keywords: TEMPUS, English language, internationalization, ERASMUS
The importance of the English language for Israeli students and graduates is undisputed; however, there
are differing views on what to teach and how, in order to best prepare for greater internationalization,
particularly as interest in the Bologna process grows. As partners in the TEMPUS (Trans-European
Mobility Program for University Studies) EFA (English for All) project (2010–2013), the English
Studies Unit at ORT Braude College was actively involved in both developing and implementing
several innovative teaching programs whose objective was to improve English proficiency. The
TEMPUS program is about to be replaced with the new ERASMUS for All program that will run from
January 2014 until 2020, with the aim of ensuring that at least 40% of 30-34 year olds should be higher
education graduates. As Israeli colleges and universities deepen their ties with their European
counterparts, opportunities for participation in exchange programs expand, for lecturers as well as for
students, and the role of the English language professionals in preparing and supporting them becomes
ever more relevant. This paper presents the overall achievements of the EFA project and introduces the
new ERASMUS for All program.
8  Biotechnology Engineering
GPI-anchored CD24: Placental expression in normal and pathological
human pregnancies
Marei Sammar1, Berthold Huppertz2 , Monika Siwetz2, Niko P. Bretz3 and Peter Altevogt3
1
2
Institute of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria, E-mail:
[email protected]
3
Tumorimmunology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg,
Germany, E-mail: [email protected]
Keywords: CD24, cytotrophoblast, placenta, preeclampsia
CD24 is a membrane glycoprotein with unusual lipid-like features. These characteristics are due to a
small protein core of 30 amino acids, extensive glycosylation, and the linkage to the cell membrane
through a glycosyl-phosphatidylinositol (GPI) anchor. In humans, CD24 is expressed by subpopulations
of hematopoietic cells, regenerating muscle cells, keratinocytes and diverse tumor types such as breast,
ovarian, non-small lung, and pancreatic carcinomas. Initially discovered as a lymphoid differentiation
marker, recently CD24 expression was described as a novel prognostic marker in different cancers.
Literature search revealed that placental CD24 is not well studied.
CD24 was affinity purified from term placental tissue and characterized by SDS-PAGE followed by
Western blot and ELISA analysis. The interaction of recombinant Siglecs with placental CD24 was
measured by modified ELISA. CD24 expression in first trimester placental and decidual tissues was
studied by immuno-histochemistry (IHC) and flow cytometry while comparative expression analysis of
CD24 mRNA in preeclamptic placental tissues was performed by real time PCR.
Western blot analysis revealed strong binding of the SWA11 mAb to the affinity purified placental
CD24, which migrated as a diffused band in the range of 30–70 kDa consistent with a high degree of Nand O-linked glycosylation. Recombinant human Siglec-10 but not 3, -5 showed strong binding to
placental CD24 in ELISA modified assays.
In first trimester placenta, IHC localized CD24 expression in villous and extravillous cytotrophoblasts
but not syncytiotrophoblast beside placental vessels. CD24 was also localized in maternal uterine glands
but was absent from decidual stroma cells. High expression of CD24 was detected in BeWo and SW71
cell lines, representing cell lines derived from human placental trophoblast. At term, placental CD24
mRNA expression was lower in preeclampsia compared to control tissues. However, protein expression
of CD24 was enhanced in early and late onset preeclampsia placentas compared to GA matched
controls, especially in a subset of placental vessels and the villous trophoblast.
Our data demonstrate the expression of CD24 in placental villous and extravillous cytotrophoblast as
well as maternal uterine glands in the first trimester. More studies are needed to evaluate how the altered
expression of CD24 may play a role in the abnormal development of the placenta in preeclampsia.
Biotechnology Engineering  9
Small molecule inhibitors of protein interaction with glycosaminoglycans
(SMIGs) – A novel class of bioactive agents with anti-inflammatory
properties
Nicholas Harris1, Chen Kaplan1, Paul Gregor2
1
21982, Israel, Tel: 972-4-9901924, Fax: 972-4-9901839, E-mail: [email protected]
2
GISMO Therapeutics Inc., Howard Beach, NY 11414, USA
Keywords: glycosaminoglycan, heparin sulfate, L-selectin, inflammatory disease
A novel class of aromatic cationic amines that inhibit protein interaction with glycosaminoglycans has
been discovered and named Small Molecule Inhibitors of Protein Interaction with Glycosaminoglycans
(SMIGs). A library of synthetic compounds was initially screened using L-selectin-IgG binding to
immobilized heparin (a highly sulfated species of heparan sulfate glycosaminoglycan [HS-GAG]). The
screen identified SMIGs that bound directly to HS-GAGs and appeared to be stable in physiological
conditions. A number of the SMIGs have scaffolds similar to those of the known drugs, chloroquine,
quinacrine and tilorone, all of which bind GAGs. SMIGs inhibited interactions of HS-GAGs with
proteins such as cytokines, chemokines and cell adhesion molecules. They displayed a certain degree of
selectivity for L- and P- selectins, IL-8, VEGF, amyloid beta, a cytomegalovirus envelope protein gB
and fibronectin. SMIGS were efficacious in three animal models of inflammation, peritonitis, paw
edema and delayed type hypersensitivity. The experimental data suggests that SMIGs could be
therapeutic in inflammatory diseases and autoimmune disorders.
Targeting atypical neuroleptics to the CNS for BBB permeability
improvement and peripheral side effects reduction
Idit Golani1, Rosa Azhari1 and Alon Shamir2, 3
1
Department of Biothechnology, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901875,
2
The Neuroscience Research Laboratory, Mazra Mental Health Center, Akko, Israel. Tel: 972-4-9954708, Fax:
972-4-9559523, E-mail: [email protected]
3
The Ruth and Bruce Rappaport Faculty of Medicine, Technion – Israel Institute of Tecnology, Haifa, Israel
Keywords: schizophrenia, antipsychotic drugs, Blood Brain Barrier, drug targeting, drug formulations
About 1% of the population suffers from schizophrenia and is treated with antipsychotic drugs
(neuroleptics). There are two types of antipsychotic drugs: typical (older, since the 1950s) and atypical
(new drugs, since the 1990s). Atypicals are marked as having fewer side effects than the older ones, but
all of them cause severe physical side effects, including heart problems, weight gain, diabetes, sexual
dysfunction, elevation of fat in the bloodstream, and more. This is the main reason for non-compliance
of schizophrenic patients with drug treatment, leading to repeated psychotic episodes and regression.
In this study, new formulations of two common atypical neuroleptics are developed to target and
facilitate drug transport across the Blood Brain Barrier (BBB). The targeting will probably increase
permeability of the drugs to the central nervous system (CNS), thus enabling reduced drug doses and
drug concentrations in blood and peripheral tissues, resulting in fewer side effects. The effectiveness of
the new formulations are being examined first in an in vitro BBB model based on cell lines and
eventually in in vivo studies using a schizophrenic mice model.
Acknowledgement: This study was supported by a grant from the ORT Braude College Research
Committee
The antifungal efficacy of formulated copper oxide nanoparticles
Michal Maoz1, Daniel Panitz2, Sigal Eichler3, Ester Segal3, Iris S. Weitz4
1
2
21982, Israel, E-mail: [email protected] (undergraduate student)
3
Department of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa 32000,
Israel, E-mail: [email protected], [email protected]
4
Keywords: copper oxide, nanoparticles, antifungal, azoles
Pathogenic microorganisms are capable of adaptation, and some manage to develop resistance even to
the most efficient drug. For example, fungi have developed several resistance mechanisms for the
widely used azoles antifungal agents. Such resistance forces the use of increased dosages, which can be
harmful to the patient and the environment. This also might increase the chances of the development of
further resistance. For these reasons, our attention turns towards unconventional antimicrobial agents, to
the field of nanotechnology. Because nano-sized materials exhibit unique chemical and physical
properties, their high surface-to-volume ratio may enable them to interact with microorganisms more
efficiently.
In our previous study, copper oxide nanoparticles (CuO NPs) have shown antifungal activity against
various types of fungi including wood decay fungi, candida, and dermatophytes. Therefore, this study
suggests the combination of CuO NPs with azole antifungal agents for lowering the effective doses.
The antifungal capacity of the formulated CuO NPs with azole derivatives was evaluated against a
variety of fungi by means of the agar dilution method, following determination of the minimum
inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). The results reveal
growth inhibition of the fungi when exposed to the formulation of the CuO NPs with azole derivatives,
both in lower concentrations than their respective MIC.
In addition, formulations of CuO NPs with the azoles, which have demonstrated better antifungal
activity, were characterized by complementary techniques. The size, shape, and self-assembly of the
formulated nanoparticles were determined by transmission electron microscopy (TEM), while the
binding nature of azole to particles was established by ultraviolet visible (UV-vis) and Fourier transform
infrared (FT-IR) spectroscopies. Thermogravimetric analysis (TGA) was used to indetify and qualify
the degree of the functionalization. Azoles show weaker binding to CuO NPs due to steric effects that
hinder the self assembly process.
Further studies are needed to investigate the mode of action and to explain the synergistic effect
between CuO NPs and azoles.
Committee.
The effect of NaCl concentration in soft cheese on whey composition and on
molecular weight profile of whey proteins
Amal Rouhana Toubi1, Maor Dahan1
1
Keywords: whey, dairy, food, proteins, salt
Dairy whey is a major byproduct of the cheese industry. On the one hand, it contains a high biological
oxygen demand (BOD), which necessitates environmental treatments. On the other hand, whey contains
valuable components, making it an important raw material for the production of nutritional and
functional products such as energy drinks and protein powders. There are different whey categories with
different compositions, depending on the specific cheese processing. In many cases whey composition
affects protein functionality and defines the whey's destination.
The aim of this work is to evaluate the effects of salt concentration in cheese on the composition of
whey and on molecular weight profile of whey proteins.
For the production of soft cheese, milk was coagulated by treatment with lactic acid bacteria (LAB)
starter culture and with renin enzyme. The coagulant was divided into six parts and a different
concentration of NaCl (0-20 gr/L) was added to each part. Different whey portions were collected
following filtration of coagulants overnight at 4ºC. Each whey portion was analyzed for its volume, pH,
salt concentration (titration), and lactose concentration (polarimetric). Each whey portion was then
lyophilized and the resulted powders were used to determine protein concentrations (Bradford) and
molecular weight profiles of whey proteins (electrophoreses).
Salt concentrations in different whey portions were in accordance to NaCl concentration in cheese. The
differences in pH values in different portions were negligible (4.6 to 4.69). The differences in lactose
concentrations in different portions were minor (47 g/L to 50.9 g/L). On the other hand, different protein
concentrations were detected in different whey portions in a non-linear pattern. The lowest protein
concentration (0.556 g/L) was detected at NaCl concentration 5gr/L, while the highest protein
concentration (0.642 g/L) was detected at NaCl concentration 15gr/L. The molecular weight profile of
proteins in the investigated whey portions matched the theoretical whey proteins profile, so
densitometry analyses are planned for the near future to detect potential differences in the different
whey portions.
We conducted a preliminary study to examine the effect of salt concentrations in cheese on the
composition of whey and on molecular weight profile of whey proteins. Different protein concentrations
were detected in different whey portions in a pattern that may be explained by the salting-in and saltingout phenomena. The molecular weight profile of proteins matched the theoretical whey proteins profile,
so densitometry analyses are needed to detect potential differences in the different whey portions.
Combined adsorption and biological degradation processes for the removal
of pharmaceutical compounds from effluents by nitrifying bacteria
Anwar Dawas1, Carlos Dosoretz1, Isam Sabbah2,3
1
The Faculty of Civil and Environmental Engineering, The Technion– Israel Institute of Technology, Haifa 32000,
Israel, Tel: 972-4-8294962, E-mail: [email protected]
2
3
The Galilee Society Institute of Applied Research, P.O. Box 437, Shefa-Amr 20200, Israel,Tel: 972 4 9504523,
Fax:972 4 950452, E-mail: [email protected]
Keywords: bio-transformation, adsorption, PhACs, ammonia-oxidizing bacteria
The occurrence and fate of pharmaceutically active compounds (PhACs) in the water environment have
been recognized as one of the emerging issues in environmental chemistry due to their potential to cause
undesirable ecological and human health effects. PhACs have been detected ubiquitously in water
environments and water distribution systems because of their high persistence and low adsorption
properties. Because these chemicals are often present in wastewater at concentrations ranging from 0.1
to 105ng/L, they cannot support cell growth and activity of organisms capable of mineralizing them
during biological wastewater treatment.
The objective of this study is to examine the transformation of pharmaceuticals at environmental and
above-environmental concentrations, by means of free and entrapped nitrifying bacteria. Nitrifying
bacteria are known for the cometabolic ability of a wide range of organic substrates, including PhACs,
by means of ammonia monooxygenase (AMO). Entrapment is expected to protect the nitrifying bacteria
from environmental competition.
The biodegradation of four selected pharmaceuticals—Ibuprofen (IBP), Ketoprofen (KTP),
Carbamezabine(CBZ) and Iopromide (IOP)—at concentrations between 0.05ppm and 3ppm was
investigated by free and immobilized enriched nitrifying cultures combined with activated carbon(AC).
The biotransformation experiments conducted with free ammonia-oxidizing bacteria (AOB) show a
clear removal of the model compounds at different concentration levels (atand above environmental
concentrations). A full biotransformation was observed for IBP and KTP where the removal of CBZ
reached 40%, and IOP 10%, respectively. The faster rate of removal (or biotransformation) was
observed for IBP and the slower one for IOP. In addition it was shown that hydroxylatedibuprofen is the
main biotransformation product supporting the assumption that the used bacterial culture was enriched
ammonia oxidizing bacteria without hetrotrophic bacteria. The most important outcome of this part is
that AMO is the responsible enzyme for biotransformation of the model compounds in AOB.
Biotransformation of the most degradable compounds (KTP and IBP) was improved by immobilized
bacteria. However, the immobilization technique has not improved the biotransformation of the less
degradable compounds (CBZ and IOP). This indicates that the limiting factor for CBZ and IOP
biotransformation is not the ratio between biomass and level of concentration. The combination of PAC
within the immobilized matrix of nitrifying bacteria leads to a significant enhancement of the removal
rate of all model compounds. This result can be attributed to the synergism between the adsorption and
biodegradation processes.
Mechanisms of skeletal muscle cell mechanotransduction
Rosa Azhari1, Iris Bonshtein1, Ehud Kroll2
1
Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901750, Fax: 972-4-9901839, E-mail: [email protected]
2
Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel,
Tel: 972-4-8293813, Fax: 972-4-8292030, E-mail: [email protected]
Keywords: Tissue engineering, skeletal muscle, mechanotransduction
Mechanotransduction has been demonstrated to play a major role in affecting proliferation and
differentiation of skeletal muscle cells and determining the morphology and properties of the tissue
obtained. Therefore, various mechanical stimulation techniques have been incorporated as essential
components in novel tissue engineering methods developed for obtaining functional skeletal muscle
tissue. Nevertheless, the relationship between the type of mechanical stimulation applied and the
resulting cell responses are not clear yet.
The aim of this work is to understand the mechanotransduction mechanisms in skeletal muscle cells and
how they are affected by the type of mechanical stimulus.
In our previous studies we have developed a computer-controlled stretching machine that was designed
to apply various unidirectional and cyclic stretching patterns on cell-seeded scaffolds, clamped
horizontally in a circulating medium bioreactor. Scaffolds were made of electrospun microfibers of
poly(caprolactone), gelatin and chondroitin sulfate. The profile of various functional and structural
proteins expressed in the engineered tissue was determined using Affymetrix GeneChip microarrays.
We demonstrated that different patterns of mechanical stimuli induce altered cell responses, even if the
final stresses applied are of the same magnitude. Up-regulation and down-regulation of genes for
structural and functional proteins were totally different in tissue grown on a scaffold in a plate and tissue
grown in the bioreactor. Slow stretching hardly affected gene expression in comparison to non-stretched
samples. Application of cyclic stresses totally changed gene expression when compared to unstretched
samples and those on which 5% deformations were applied twice daily.
Up-regulation and down-regulation of gene expression of specific proteins following the change in the
mechanical stimulation regimes might point to the mechanisms of mechanotransduction induced under
each of the stretching patterns. Major mechanotransduction pathways will be discussed and related to
the experimental results.
Acknowledgement: This study was supported by grants from the Israeli Science Foundation (618-08)
and the ORT Braude College research committee.
Biomed business model design case study: BoneCure AMCA ammonio
methacrylate copolymer type A membrane for treatment of severe bone
defects in pets
Harry Langbeheim
21982, Israel, Tel: 972-4-9901907, Fax: 972-4-9901839, E-mail: [email protected] and RegeneCure Ltd. 19
Hartom Street, Jerusalem 9777518, Israel.
Keywords: business model, vertical integration, TTM, bone grafting, membrane implant, GBR
The main business model structures in biotech are the vertical business model, the horizontal (platform)
business model, and the fully integrated pharmaceutical company (FIPCO). Many small biotechnology
and medical device companies focus on research and work in a “short vertical” model, where the
product prototype is sold or partnered out to a commercial partner. This case study shows that product
focus with vertical integration over the whole value chain enabled flexibility and the ability to respond
to new business opportunities that accelerate time-to-market (TTM).
The regenerative AMCA membrane implant is the initial product of a vertically integrated small biomed
start-up that develops and manufactures its products in-house. The product is a polymeric membrane
from ammonio methacrylate copolymer type A (AMCA) and polyethylene glycol (PEG 400) wrapped
around bone edges at the bone defect site supporting human mesenchymal stem cells (hMSC)
adherence, proliferation, and differentiation. This helps promote rapid bone healing by Guided Bone
Regeneration (GBR). The membrane can be cut to any desired configuration and size, is suture-able and
drillable, and may be used alone or in conjunction with external or internal bone fixation devices such as
plates and screws.
Pre-clinical and clinical development of the AMCA membrane for orthopaedic trauma and dental
indications and the respective regulatory 510(k) marketing approvals is an extended process that takes
three to five years. An AMCA membrane implant product was manufactured and packaged routinely as
a final product for pre-clinical studies in rabbits and sheep. The rabbit study showed the product to be
safe and the healing time to be about forty percent quicker than normally observed using current
standard of care therapies. The veterinary surgeons involved in the pre-clinical studies pointed to the
medical needs of severe fracture cases in companion animals that they operated on in referral pet clinics.
Since there are no regulatory requirements for pre-marketing approval for medical devices in pets, the
AMCA membrane was introduced as the first regenerative membrane implant developed for household
pets. The AMCA membrane is now marketed and used worldwide by veterinary surgeons in pets (brand
name: BoneCure) for indications like non-union, large bone gaps, arthrodesis, fresh fractures,
comminuted fractures, and grade I open fractures.
Top management in biomed industries are actively seeking to innovate their business models to improve
their ability to both create and capture value. This case study shows that vertical integration allows
generating revenue at several levels during the product development process.
The effect of pharmacologic inhibition of the ErbB signaling pathway during
juvenile life on complex behaviors in adulthood
Idit Golani1, Hagar Tadmor2,3 , Alon Shamir2,4
1
Department of Biotechnology, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901875,
2
The Neuroscience Research Laboratory, Mazra Mental Health Center, Akko, Israel; Tel: 972-4-9954708, Fax:
3
Faculty of Medicine in the Galilee, Bar-Ilan University, Zefat, Israel
4
The Ruth and Bruce Rappaport Faculty of Medicine, Technion – Israel Institute of Technology, Haifa, Israel
Keywords: neuregulin, ErbB4 receptor, schizophrenia, ErbB kinase inhibitor, cognition, social
interaction, working and reference memory
The ErbB signaling pathway has been genetically and functionally implicated in schizophrenia.
Numerous findings support the dysregulation of NRG and EGF signaling in schizophrenia. Perinatal
exposure to EGF or NRG and postmortem human brain studies suggested that hyperfunction of the
ErbB signaling pathway contributes to the development of schizophrenia. On the other hand, evidence
from hypomorph NRG-1 mice and HB-EGF and ErbB4 knockout mice proposed that a reduction in
ErbB signaling may trigger cognitive dysfunction and emotional processing impairments. However, it is
unclear whether changes in ErbB function and expression, observed both in patients and animals,
represent direct effects or compensatory responses, and whether the alteration in the pathway occurs
during postnatal brain development or at adulthood. To further explore the role of the ErbB signaling
pathway in complex behaviors related to schizophrenia, we characterize in adulthood the behavioral
profile of pharmacological blocking of the pathway during juvenile life, which is a highly important
period in brain development and maturation. Toward this end, mice were injected, at postnatal day 24,
once a day for 14 days with the potent and highly selective pan-ErbB kinase JNJ-28871063, an ErbB
inhibitor that crosses the blood brain barrier.
Here, we report that chronic administration of the pan-ErbB kinase inhibitor during juvenile life has no
effect on reversal learning in adulthood. However, during the acquisition phase, JNJ-28871063 treated
mice needed significantly more correct-response trials to reach the learning criterion than their saline
injected control group. In addition, JNJ-28871063 injected mice consumed less sucrose than their
control group in the sucrose preference test. Inhibition of the pathway during juvenile life did not affect
exploratory behavior and locomotor activity in the open field, social interaction and social memory, and
working and reference memory as measured in the radial arm maze. These finding suggest that changes
in ErbB signaling during postnatal brain development can result in learning dysfunction and in nonhedonic behavior, and support the notion that the ErbB signaling pathway is involved in the
neurobiology of complex behaviors. However, this finding cannot pinpoint the critical period for the
involvement of the pathway in complex behavior related to schizophrenia and other psychiatric disorder.
Additional studies are required to determine this critical time in brain development.
Electrical and Electronic Engineering  17
Use of heavily masked normalized correlation for 2D label detection
Samuel Kosolapov
Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Keywords: image processing, object detection, normalized cross-correlation, 2D label
A plurality of 2D labels in some images (for example, traffic signs in a photo) can be detected using a
standard approach to find template sub-images (TSI) in the full-size image (FSI). This is called
normalized cross-correlation (NCC). Practically, the MATLAB function normxcorr2 (TSI, FSI) can be
used in this case. The result of this function is the matrix of correlation coefficients (CC). The values of
CC are in the range [-1.0..1.0] where a value of 1.0 means that an exact match for a TSI is found in the
FSI. The position of CC with maximal value points to the “best match” (after the relevant shift
addition). However, standard NCC can be used for a TSI with a rectangular shape.
In some applications, a non-rectangular TSI or ring-shaped TSI must be used; for example, to detect
borders of traffic signs or markers of 2D labels. Standard NCC cannot be used in these cases and must
be adapted to support them.
A modified algorithm called the Heavily Masked Normalized Cross-Correlation (HMNCC)—
supporting wider class of TSI—was designed, implemented, and tested. Both NCC and HMNCC are not
invariant with respect to imaging scale, rotation, and perspective distortions. However, when the TSI
has a ring shape, a small set of TSIs of different sizes can be used to find TSI with the highest CC.
NMNCC was implemented as a C# function. The function provides the same results as NCC for
rectangular TSIs, but can also be used for TSIs of different shapes when NCC cannot be used.
Heavily Masked Normalized Cross-Correlation can be seen as an extended version of NCC and thus
can be used in a wider spectrum of applications.
Acknowledgement: This study was supported by a grant from the ORT Braude College research
committee under grant number 5000.838.3.1-58.
18  Electrical and Electronic Engineering
Quantum-dot cellular automata serial decimal subtractors
Michael Gladshtein
Prof. Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982,
Israel, Tel: 972-4-9086424, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: quantum-dot cellular automata, decimal subtractor, Johnson-Mobius code
Quantum-dot cellular automata (QCA) is a possible alternative to the CMOS technology due to its high
density, high switching speed, and ultralow power dissipation. Because the signal propagation through a
QCA wire is similar to the signal propagation through a conventional shift register, it is advantageous to
use serial data transfer and processing. Besides, the growing market for financial and commercial
computer applications requires direct processing of decimal information, without representation and
conversion errors.
Among possible binary-decimal encodings, the biquinary 5-bit decimal Johnson-Mobius code (JMC) is
the most interesting: it is close to the minimal code and supports the simplest arithmetic processing of
its binary component (by inversion all of the bits) and quinary component (by twisted-ring rotation of
the code—the shift operation in a Johnson counter).
The one-digit serial decimal JMC adder previously designed by the author contains two serial bit
flippers, a decoder, a serial left barrel twisted-ring rotator, and a one-bit serial left twisted-ring rotator—
the output of which provides a serial JMC of sum. The carry-out bit is calculated by simple logic circuit.
The required number of cells for such adder implementation using multilayer crossovers is 1130. The
delay is 10 clock cycles (CLK).
The serial decimal JMC subtractor design is the next step in researching the new nanocomputer
architecture based on serial decimal processing and JMC encoding. The two basic methods of decimal
subtraction are well known: “addition of complements” and “direct subtraction.” In accordance with
these methods, two original QCA one-digit serial decimal subtractor designs are presented.
The first subtractor uses the one-digit serial decimal JMC adder and the serial 9’s complementer, which
contains two shift registers implemented by delay elements, an inverter, and the output multiplexer
implemented by two-input logic AND and OR gates. The second subtractor has the same structure as
the serial decimal JMC adder, but rotator units perform right rotation.
The QCADesigner software was used for QCA placement and simulation of the subtractors. Multilayer
crossovers were used. The required number of cells is 1486 and 1128 for the first and second subtractor
respectively. The simulation results demonstrate that the proposed subtractors work correctly. The delay
is 14 and 10 CLK for the first and second subtractor respectively.
The proposed technical solutions closely correspond to the QCA nanotechnology—serial processing-inwire. Moreover, the JMC subtractors have the error checking capability, as the result of code
redundancy.
Acknowledgement: This study was supported by a scholarship for “Conversion of hours of teaching to
hours of research” from the ORT Braude College research committee.
A small signal characterization of MOS transistor current for CMOS
submicron technology
Radu Florescu1, Guy Gontmacher2
1
2
Keywords: NMOSFET, threshold voltage, effective mobility, I/V characteristic, inversion coefficient
(IC), BSIM4 simulation model
Analog CMOS design is greatly complicated by the large change in transconductance (gm), output
conductance (gds), and body-effect transconductance (gmb) over the continuum of inversion level and
channel length. In modern IC design, MOS devices may be operated anywhere in the weak to strong
inversion continuum and over the range of available channel lengths. Simple, accurate, small-signal
MOS analysis is available only in weak inversion and strong inversion, and in the latter only if mobility
reduction and velocity saturation effects are not considered. However, the modern designer may operate
devices in moderate inversion for power efficient transconductance and low VD SAT, both needed for
low supply voltage operation. Additionally, the square-law region of strong inversion vanishes as deeper
submicron devices exhibit mobility reduction and velocity saturation effects at increasingly lower levels
of inversion. For the new CMOS technologies, a dramatic reduction of the mobility measured at short
gate length has been observed. Moore's Law states that the number of transistors per integrated circuit
doubles every two years. The current 90 nm generation node produces CMOS devices with an Lg of
~50 nm, and a projected Lg of ~10 nm.
The aim of this work is to create a new model of I/V characteristic for NMOSFET, for modern analog
CMOS design anywhere in the continuum of inversion level and channel length.
In our lecture, a semi-empirical mobility model has been formulated and verified with experimental data
for various bias and doping conditions. The model includes basic scattering mechanisms and doping
dependence, and yet retains the compact form for easy parameter extraction and drain-current modeling.
The inversion coefficient (IC) is used as the transconductance and output conductance characterization.
To verify the I-V model, a set of experimental data is considered for low power NMOSFET (sub-micron
gate length and SiO2 low thickness). Also the semi-empirical BSIM4 Simulation Model (Berkeley Short
Channel MOSFET Model) is considered.
Our model has been successfully applied to a complete modeling of the short-channel devices. Initial
results are given, illustrating our model’s accuracy.
The characterization methodology can be applied to deeper submicron processes.
Efficiency of LED panel implementation for office or factory lighting
Radu Florescu1, Raya Shechtman2
1
2
Keywords: light emitting diode (LED), compact fluorescent CFL), illuminance, luminaire
Lighting-class LEDs are now available that deliver the brightness, efficacy, lifetime, color temperatures,
and white-point stability required for general illumination. As a result, these LEDs are being designed
into most general lighting applications, including roadway, parking area, and indoor directional lighting.
LED-based luminaires reduce total-cost-of-ownership (TCO) in these applications through maintenance
avoidance (since LEDs last much longer than traditional lamps) and reduced energy costs. Lightingclass LEDs offer efficient, directional light that lasts at least 50,000 hours. Indoor luminaires designed
to take advantage of all the benefits of lighting-class LEDs can:
-Exceed the efficacy of any incandescent and halogen luminaire;
-Match the performance of even the best CFL (compact fluorescent) recessed downlight;
-Provide a lifetime five to fifty times longer than these lamps before requiring maintenance;
-Reduce the environmental impact of light: no mercury, less power-plant pollution, and less landfill
waste;
The aim of this work is to compare LED-based luminaires with linear fluorescent lamps panels using a
new method.
In our paper, a point-to-point illuminance calculation method is developed in consideration of each LED
lamp contribution. With all the system efficiencies estimated, the actual number of LED lumens
required to achieve the design goals can be calculated. For this calculation, only the light efficiencies
(optical and thermal) are used. The target application is better served by creating a new LED luminaire,
then designing the luminaire's light output to match or exceed an existing luminaire, with several
advantages. First, an existing design is already optimized to target a known application and can provide
guidance for setting the design goals around light output, cost, and operating environment. Secondly, an
existing design is already in an accepted form factor. Switching to the LED luminaire is easier for the
end user if the form factors are the same.
Our model has been successfully applied for an office lighting calculation.
The characterization methodology can be applied to all kind of lighting design. LED luminaries exceed
the efficiency of any fluorescent luminaries.
Approximated methods of analysis guided modes in large 2D photonic arrays
of identical waveguides
Elena Smith1, Vladislav Shteeman2, Elyahu Kapon3, Amos A. Hardy4
1
2
3
Laboratory of Physics of Nanostructures, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne,
Switzerland, Tel: 41-21-6933388, Fax: 41-21-6935480, E-mail: [email protected]
4
Department of Electrical Engineering – Physical Electronics, Engineering Faculty, Tel Aviv University, Ramat
Aviv, 69978, Tel Aviv, Israel, Tel: 972-3-6408959, Fax: 972-3-6423508, E-mail: [email protected]
Keywords: coupled-mode theory, photonic crystals, approximate methods
Photonic devices, made up of coupled waveguides or phase-locked laser diodes, have drawn
considerable attention in recent years, as part of a wider class of electro-optical components known as
photonic crystals. Accurate numerical analysis of optical properties and performances of photonic
crystals with traditional numerical techniques (such as Finite Difference Time Domain or Plane-Wave
Expansion) is a complicated problem, which can take a long time and consume large computer
resources.
The purpose of this research was to develop new, fast, and accurate methods of analysis of 2D photonic
arrays composed of a large number of identical elements (waveguides/lasers).
We started with the coupled-mode formalism, describing guided optical modes in arrays of coupled
waveguides in terms of sets of guided modes of the individual elements, multiplying each by its partial
amplitude. Based on this formalism, we developed approximate numerical and analytical methods of
analysis of guided modes in 2D photonic crystal devices containing a large number of identical elements
(waveguides/lasers). These methods avoid a tedious and complicated procedure of constructing a
coupling matrix and subsequent solution of the exact coupled-mode eigenequation.
We found that the spatial distribution of optical modes and their associated propagation constants,
acquired with the approximate methods, are in very good agreement with those produced by the
standard well-established techniques. Nevertheless, analysis of photonic devices with the approximate
methods requires only several tens of seconds on a standard PC (even for devices containing several
hundred waveguides), as opposed to several hours for traditional computational techniques. The
advantages of this approach are particularly noticeable when optimizing large-scale 2D photonic
components. Moreover, for the first time, analytical expressions for guided modes in the devices under
consideration became available. These expressions allow asymptotic evaluation of behavior of guided
modes as a function of the physical parameters of the devices (e.g., number of solitary elements, type of
photonic lattice (rectangular/square/hexagonal etc.), array period, core – clad contrast, etc.).
The approximate methods developed in this research allow fast and accurate analysis of guided modes
in 2D photonic crystals, composed of a large number of identical waveguides/lasers.
Acknowledgement: This study was supported by the ORT Braude College research committee.
New printed meta-material antennas
Albert Sabban
Department of Electrical and Electronic Engineering, Ort Braude College, Karmiel, P.O. Box 78, Karmiel 21982,
Israel, Tel: 972-4-8759111, Fax: 972-4-8759111, [email protected]
Keywords: meta-material, printed antennas, microstrip antennas
The communication and biomedical industries are in continuous growth in the last decade. Low profile
small antennas are crucial for the development of commercial compact systems, yet small printed
antennas suffer from low efficiency. Meta-material technology is used to design small printed antennas
with high efficiency. Design considerations, together with computed and measured results of printed
meta-material antennas with high efficiency, are presented in this paper. The proposed antenna may be
used in communication and medicare systems.
Meta-material technology is used to develop small antennas with high efficiency. A new class of printed
meta-material antennas with high efficiency is presented in this lecture.
At first a microstrip loaded dipole antenna was designed to provide horizontal polarization. The antenna
is shown in Figure 1.a.The second step was to design the same antenna with split ring resonators. The
antenna is shown in Figure 1.b. Periodic split-ring resonators and metallic posts structures may be used
to design materials with dielectric constant and permeability less than 1. The antenna consists of two
layers. The first layer consists of RO3035 0.8mm dielectric substrate. The second layer consists of RTDuroid 5880 0.8mm dielectric substrate. A printed slot antenna provides a vertical polarization. The
printed dipole and the slot antenna provide dual orthogonal polarizations. The dimensions of the dual
polarized antenna shown in Figure 1 are 26x6x0.16cm. The antenna was analyzed using Agilent ADS
software. The matching stub width and length are optimized to get the best VSWR results at the antenna
input ports. The number and location of the coupling stubs control the axial ratio value. The axial ratio
value may vary from 0dB to 20dB due to the different location and number of the coupling stubs.
(a)
( b)
Fig. 1: a. Printed dual polarized antenna b. Printed antenna with split ring resonators
The antenna bandwidth is around 10% for VSWR better than 2:1. The antenna beam width is around
100º. The gain of the antenna without SRR is around 2dBi. The resonant frequency of the antenna with
SRR is 400MHz, around 10% lower than the resonant frequency of the antenna without the SRRs.
Metallic strips have been added to the antenna with SRR. The bandwidth of the antenna with metallic
strips is around 50% for VSWR better than 3:1. The gain of the antenna with SRR is around 4 to 5dBi.
Meta-material technology is used to develop small antennas with high efficiency. A new class of printed
meta-material antennas with high efficiency is presented in this paper. The bandwidth of the antenna
with SRR and metallic strips is around 50% for VSWR better than 3:1.
Industrial Engineering and Management  23
Further results for the longest queue (LQ) system with exchangeable items
Rachel Ravid1, David Perry2, Onno Boxma3
1
Department of Industrial Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901849, Fax: 972-4-9901852, E-mail: [email protected]
2
Department of Statistics, University of Haifa, Haifa 31909, Israel, Tel: 972-4-8249153, Fax: 972-4-8240563, Email: [email protected]
3
Department of Mathematics and Computer Science, Technische Universitiet Eindhoven, The Netherlands, E-mail:
[email protected]
Keywords: longest queue system, exchangeable items
Exchangeable-item repair systems have received considerable attention in the literature because
repairable-type items are often essential and expensive. Many organizations use multi-echelon,
repairable-item systems extensively to support advanced computer systems and sophisticated medical
equipment. The items are admitted to one line but the customers wait and are marked according to their
sources.
The aim of this research is to compute the steady state distribution of the difference between the queue
lengths and the marginal distribution of the queue lengths.
The renewal cycle (Busy period + Idle period) is represented as a three state Markovian renewal
process. The system is considered to be in state U (D) if queue 1 is longer (or shorter) than queue 2, and
in state E if the queues are equal. Renewal theory is applied to compute the system steady state
distribution. The probability mass function of the difference between the queue lengths is computed
using the conditional distribution of the queue lengths, which was derived by the authors in a previous
paper. On the continuation, the marginal distribution of the queue lengths is derived from the set of the
balance equations.
We provide explicit results for the probability mass function of the difference between the queue
lengths. The marginal queue lengths are derived from the joint steady states distribution of the states on
which the absolute difference between the queue lengths is, at most, one.
24  Industrial Engineering and Management
Controlling FMS based on dynamically creating local optimal schedules for
dynamically selected appropriate operational criteria
Boris Shnits
Department of Industrial Engineering and Management, Ort Braude College, P.O. Box 78, Karmiel 21982, Israel,
Keywords: FMS control, dynamic scheduling, multi-criteria decision making
This research focuses on developing a control methodology for flexible manufacturing systems (FMSs)
that operate in a highly dynamic environment, characterized by random arrival of work orders, random
machine breakdowns, changes in due dates, and other disruptions. The literature argues that for such
environments an adaptive scheduling approach seems to be more effective than other control methods.
Adaptive scheduling means choosing an appropriate schedule/ scheduling policy based on the current
state of the shop floor at pre-specified decision points. The adaptive control methodologies suggested in
previous studies usually do not consider dynamic changing of the operational decision criteria in
accordance with system condition changes, and are based on the use of simple scheduling/dispatching
rules, providing myopic decisions and a non-delay type schedule. Such an approach does not guarantee
the best scheduling decisions, especially for FMS, which comprises versatile machines, and as a result
cannot fully exploit the flexibility offered by FMS.
The adaptive scheduling mechanism proposed in this study is based on incremental optimization. It
combines dynamic selection of the appropriate decision criterion, and solving, subject to this criterion,
the local optimization problem to select the next jobs to be processed on available machines. Two types
of the optimization-based dynamic scheduling problem were formulated: 1) the completely local
assignment problem, which when solved, determines only the next job for each available machine; 2)
the scheduling problem, which when solved, determines the best schedule (job sequence on each
available machine) for a scheduling period of predefined length. The optimization models of the above
types were formulated for different objective functions. These models were integrated in the overall
multi-criteria control scheme that is based on a two-tier decision making hierarchy. Tier 1 is used to
determine the dominant decision criterion that is of high importance at the current moment, and
according to this criterion, selects the appropriate objective function for the dynamic scheduling
problem that is solved in Tier 2.
The suggested multi-criteria dynamic scheduling methodology was implemented and evaluated using a
simulation environment based on the Arena simulation tool. The simulation model is integrated with the
mathematical scheduling models (mentioned before) that are solved online, during the simulation run, at
each decision point (at the beginning of each scheduling period) based on the current system state at
those points.
Impacts of practicing lateral transshipments on designing and operating a
supply chain
Hussein Naseraldin1, Yale T. Herer2
1
Department of Industrial Engineering and Management, ORT Braude College, P.O.B. 78, Karmiel 21982, Israel,
Tel. 972-4-9901917, Fax: 972-4-9901852, E-mail: [email protected]
2
Faculty of Industrial Engineering and Management, Technion – Israel Institute of Technology, Haifa, 32000,
Israel, Tel. 972-4-8294423, Fax: 972-4-8295688, E-mail: [email protected]
Keywords: lateral transhipments, risk-pooling, simultaneous optimization, implicit function theorem
Lateral transshipment is a recourse activity intended to improve the performance of the system by
moving stock from one retail outlet to another. Typically, transshipments are carried out whenever a
retail outlet faces an excess of inventory and another retail outlet faces a shortage of inventory.
The aim of this research is to evaluate the impact of practicing lateral transshipments on designing a
supply chain and operating it; specifically, to quantify the impact that lateral transshipment may have on
system performance.
We investigate a system that comprises retail outlets and customers, both of which are located on a
homogenous finite line segment. In each period, the customers on the whole line pose a stochastic
demand that is normally distributed. We analyze this stochastic inventory system in an infinite-horizon
setting and use the total expected cost as the performance measure. Managing such a system entails
determining various decisions that have different planning horizons. Decisions such as the number and
location of retail outlets are part of the strategic design of the supply chain. Decisions such as the
inventory replenishment levels and the lateral transshipment quantities are part of the operational
planning of the supply chain. Although integrating decisions that affect different planning horizons, e.g.,
strategic and operational decisions, necessarily leads to a better solution than if they were determined
separately, this integration is rare. This rareness is due to the difficulties in modeling the interrelated
nature of these decisions. Modeling the interaction among operational, tactical, and strategic decisions is
about properly integrating the corresponding decision variables into a single model that simultaneously
finds the optimal values of each decision variable.
Our contribution in this study focuses on shedding light on the relations among various settings of the
supply chain at hand. We compare our proposed simultaneous approach to a hierarchical approach in
which first we determine the strategic decisions and then determine the tactical decisions, subject to the
strategic decisions made earlier. After these two hierarchies of decisions are made, we consider the
operational decisions, subject to all decisions determined earlier. This approach of decision-making
leads to solutions that are not necessarily the best solutions that the decision-maker can make.
Our model sheds light on the benefits of integrating these decisions. The analysis of the model enhances
the understanding of the impacts of practicing lateral transshipments on the system's performance.
Committee.
Project management, systems engineering and what's in between
Meir Tahan
Department of Industrial Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-547589430, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: project management, systems engineering, PMBOK, SEBOK
The Project Management Body of Knowledge (PMBOK) defines five phases in the project lifecycle:
initiating, planning, executing, controlling, and closing. Nine knowledge areas are required for
implementing the project management cycles: project integration management, project scope
management, project time management, project cost management, project quality management, project
human resources management, project communication management, project risk management, and
project procurement management.
The systems engineering (SE) lifecycle model is quite different, containing many more than five phases.
It starts at the needs phase and ends at the retirement stage. The SE also has many more than nine
knowledge areas.
Engineering projects should combine both methodologies to create a product or a system. Using the
PMBOK model and the SE Vee model, the interaction between project management and systems
engineering are explored and the common areas are exposed to get a better understanding of the process
of an engineering project.
HR outsourcing and absenteeism: A cross countries study
Hilla Peretz1, Yitzhak Fried2
1
Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel 21982,
2
Whitman School of Management, Syracuse University, USA, 721 University Avenue, Syracuse, NY 13244, U.S.A,
Tel: 1-315- 4433639, Fax: 1-315- 4421449, Email: [email protected]
Keywords: human resources, outsourcing, national culture
Outsourcing is defined as an organization’s formal agreement with an external enterprise for the
delivery of goods or services that would otherwise be offered in-house. Proponents of HR outsourcing
point to such benefits as cost reduction, increased service quality, and increased access to experts in
specialized areas. Interestingly, despite the fact that HR outsourcing has become widespread, most of
the research on the conditions that contribute to outsourcing, and the effect of outsourcing on
performance, is generated from the US.
Our present study aims to address this gap in the literature on outsourcing. Specifically, we investigate
HR outsourcing across multiple countries with different societal cultures. We argue that a lack of fit
between national cultural values and outsourcing of HR practices increases resistance among
employees, resulting in negative reactions such as higher absenteeism.
The study sample consisted of 4,740 organizations from 21 countries. Data for the study were obtained
from the CRANET database for organizational level measures, and the Global Leadership and
Organizational Behavior Effectiveness (GLOBE) database for national level cultural values. Nine items
were used to measure the use of outsourcing on a 0-4 scale (0 = not at all; 4 = only outsourcing) for the
following HR functions: payroll, pensions, benefits, training and development, workforce reduction, HR
information systems, recruitment, selection, and routine queries from managers/employees. To measure
cultural values, data for three values were obtained: future orientation, uncertainty avoidance, and
collectivism. We measured the organizational outcome of absenteeism using the average annual
absenteeism (number of days) in the organization. Because of the nested structure of the data
(organizations within countries) we used multilevel hierarchical linear modeling (HLM) analysis for
modeling the structure of the data. We used the maximum likelihood method to estimate the values of
the regression coefficients, and the intercept and slope variance.
The findings generally supported our hypotheses. Specifically, the results indicated interactive effects
between culture variables and outsourcing variables (use of outsourcing and decreased percentage of
employees due to outsourcing), on absenteeism; in low future orientation and high uncertainty
avoidance societies, organizations tended to have higher absenteeism if they implemented outsourcing
HR activities.
The results increase our understanding of the effect of particular national cultural values on outsourcing
in HRM and their effect on the behavioral outcome of absenteeism. They provide a start toward
identifying the conditions under which cultural differences are associated with similar versus different
HR practices. Regarding practical implications, the results suggest that managerial decisions concerning
whether to outsource HR functions should take into account the national culture in which the
organization is embedded, to minimize the potential adverse effect of outsourcing on employees’
reactions.
Committee under grant number 1...0.0.0005-51.
Theories and theorizing in organizations
Doron Faran
Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
Keywords: organizational learning, theory-of-action, epistemology, management
Organizational learning is tightly related to the theory-of-action (TOA) concept, which links means to
ends, but less to the explanatory theory (ET) counterpart. The ET concerns causes and effects that
explain why certain means lead to expected ends; hence both theories should be consistent. The ET has
some advantages over the TOA for validation purposes, yet is latent in both research and practice.
The research addresses the awareness of the ET in organizations, its explication, and its consistency
with the TOA.
This research is based on a multiple longitudinal case study.
Organizations succeeded in explicating their ET only through intensive facilitation; they did not notice
inconsistencies between their theories (ET vs. TOA).
Organizations are barely aware of their theories and the explanatory theory is detached from the TOA.
The value and timing of introducing knowledge in decision support systems
Nirit Gavish1 and Hussein Naseraldin2
1
2
Keywords: Decision support system, information, cognitive system, experience
Advances in technology, computational power, and artificial intelligence have enabled the evolvement
of high-level cognitive computerized systems. Using these systems, the human operator can perform
complex tasks such as planning, control, diagnosis, and decision making. It can be speculated that a
person utilizes a decision support system most effectively if she accepts the way the system analyzes the
problem and recommends how to handle it. Otherwise, the person is prone to ignore the system’s help
and recommendations.
The current study evaluated the evolution of the human’s cognitive style of decision making with a
simulation that included purchasing decisions. We investigated the effect of aids given in two different
phases. The human’s cognitive styles in decision-making can be classified into two types: analytic—
plan-based, rational, explicit, and quantitative—or heuristic, spontaneous, and intuitive. In the analytic
type the decision maker uses a systematic approach, rational thinking, and explicit models of the
situation (sometimes quantitative). In the heuristic type, the decision maker uses common sense and
intuition, and her decision-making is more spontaneous. A common finding in the literature is that the
human performer starts her interaction and decision-making process with an explicit, analytic, and
theory-based style, and after gaining experience with the results of her decisions, she shifts to an
implicit, experience-based, and non-analytic style. For example, when she starts as a novice industrial
engineer, her decisions about inventory management rely on models she has learned during her
undergraduate studies. After she gains experience with the good or bad decisions she has made, her
decisions rely implicitly on her accumulated experience, and she does not refer to theoretical models
any more, as long as she is facing the same level of challenge in her decision making process.
In addition to abovementioned changes, the current study examined the effect of analytic information
given to the human operator on her decision making, and whether this effect changes if it is given in
different phases during the interaction with the simulation.
Ninety students from ORT Braude College served as participants. Participants were invited to the lab
and had two successive sessions of interaction with a simulation-based game. Thirty participants did not
receive any aids during the interaction (No-Information group). Thirty participants were introduced, at
the beginning of the first session, to an algorithm that would help them to make their decisions better
(Preliminary Information group). Thirty participants were introduced to the same algorithm, but only at
the end of the first session of interaction, before the second session started (Mid-term-Information
group). We report the participants’ decisions over time, their cognitive style, and the extent to which
they used the algorithm.
Acknowledgement: This research was supported by ORT Braude College.
Contribution of industrial engineering to the management of medical
systems
Yariv N. Marmor
Center for the Science of Health Care Delivery, 200 1st Street SW, Rochester, MN 55905, USA, Tel: 1-5072849975, Fax: 1-507-538-7957, E-mail: [email protected]
Keywords: healthcare, industrial engineering, system, scheduling, optimization, simulation
In the past 40 years, healthcare expenses as a proportion of the GDP are growing rapidly in developed
countries. This motivates providers to find ways to reduce costs, while maintaining a high level of care
for the growing populations. Since simple methods are found to have limited impact on the healthcare
systems, modern techniques need to be implemented.
The aim of this presentation is to introduce actual case studies from three years of post-doctoral research
at the Mayo Clinic, to demonstrate the contribution of the industrial engineering (IE) field to the
management of healthcare systems.
Scheduling, bed capacity planning, and staffing are some of the issues that the IE staff at Mayo Clinic
deals with on a regular basis. The clinical area can range from the Imaging department, to Intensive
Care Units (ICU), step down units, or the Emergency Room (ER). The IE tool kit consists of data
mining techniques, simulation, linear programing, queuing, and more.
Four case studies are reported. (1) A Positron Emission Tomography (PET) scanner scheduling case,
where a simulation model was used to reduce patients’ waiting time while increasing accessibility.
Since the patients are introduced with radiopharmaceuticals before the scan, the waiting time has a
clinical aspect as well as an impact on the service level. (2) Cardiovascular surgery (CVS) for bed
capacity planning that balances the use of both the ICU and the step down unit using simulation and
linear programming. A service level was introduced to balance between the high service level and
operational aspects such as utilization. (3) The use of data mining as the basis for integer programing to
increase utilization, access, and profit to the spine surgery department. (4) A combination of queuing
techniques and simulation to reduce staffing load at the ED.
The use of IE techniques in the healthcare industry can significantly impact not just its financial and
operative aspects, but also the provided level of care.
Round table brainstorming discussion of the IE&M Department
Discussion issue: How to enhance/encourage/stimulate faculty synergy through
research collaboration?
Keywords: research collaboration, intra institutional peers collaboration, interdisciplinary
research groups.
Topics to be discussed:

What is research collaboration? What motivates research collaboration? What are
factors contributing to collaboration (complexity of problems, growing
professionalization, pooling one’s knowledge with others, combination of
theoretical and experimental skills/approaches)?

Whether cooperation is vital and relevant for our department’s research? What are
the benefits and costs of collaborating (sharing and transfer of knowledge, skills,
techniques, fair division of labor, cross-fertilization of ideas across disciplines, new
insights, intellectual companionship)? Whether cooperation enhances scientific
impact?

Applied vs. theoretical – what is more actual for IE&M research? What areas of
research conducted at the department may be of mutual interest?

What is the optimal distribution of roles within the research group? Who manages
collaboration? The problem of time-consuming collaboration, assessing
contribution and “et al.” problem. What is the optimal research group size? How to
overcome the difficulties of cooperation?

How to encourage and improve formal (seminars, conferences) and informal
communications and links leading to cooperation? How to involve students into
research activity?

Cooperation during writing up and presenting the research results at faculty
seminars, national and international conferences.
32  Mathematics
Some inequalities for the horosphere function on the Hilbert ball
Mark Elin1, Marina Levenshtein2 and David Shoikhet 3
Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972--4 7046409, Email: [email protected]
2
Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9086433, Email: [email protected]
3
1
Keywords: Hilbert ball, holomorphic mapping, iterates, Poincaré hyperbolic distance,
 -nonexpansive mapping
Our goal is to trace common features as well as differences between the boundary behavior of
holomorphic (  -nonexpansive) self-mappings of the complex unit disk (in the one-dimensional case)
and the complex unit ball (in higher dimensions).
The behavior of such mappings inside the disk (ball) is usually studied in terms of the Poincaré noneuclidean hyperbolic distance  ( z, w) between two interior points z and w . However, this distance
cannot be applied to study of boundary behavior of such mappings, since  ( z, w) tends to infinity if
either z or w approaches the boundary. To avoid this deficiency, one introduces another non-euclidean
``distance’’ d ( z, w) from an interior point z to a point w in the closure of the ball. It is called the
horosphere function.
At first, we discuss some known boundary properties of holomorphic mappings in the one-dimensional
case, including the famous Julia-Wolff-Carathéodory Theorem, the classical Denjoy-Wolff theorem,
Osserman’s inequality, and Lipcshitz-like inequalities. A natural question that arises here is: which of
these properties holds in more general settings, say, for  -nonexpansive mappings that are not
holomorphic in the disk or ball? We discuss some known generalizations of the one-dimensional
assertions to the complex Hilbert ball and present new results in this direction.
Furthermore, we give a sufficient condition for locally uniform convergence of the natural iterates of a
holomorphic self-mapping of the complex Hilbert ball to a fixed point.
Mathematics  33
Exponential estimates of solutions of parabolic pseudodifferential equations
Yakov Lutsky
Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901997, Fax:
972-4-9901802, E-mail: yalutsky@ braude.ac.il
Keywords: parabolic pseudodifferential operators, parabolic differential operators with growing
coefficients, weighted estimates of solutions of the nonhomogeneous Cauchy problem
In the present work we study the Cauchy problem for a parabolic pseudodifferential operator (ψdo) of
the form
u  x 
 Op  a  x,     u  f  x  , u  0, x   u0  x  ,
x0
(1)
where symbol a  x,    can have power growth in the variables x and   . Moreover, we assume that
n
the symbol a  x,    has an analytic extension in a tube domain R   i . Under these conditions we
prove the existence and uniqueness of a solution of the Cauchy problem (1) in the spaces of functions
defined on  0, T  , T  0 , and taking their values in exponential weighted Sobolev spaces. Applying this
result we obtain for the solution of Cauchy problem, uniform with respect to the variable x0 , the
following estimates

max xu  x0 , x   Ce  x  ,
x0 0,T 
where   x   and the order of the derivatives is defined by the data of the problem (1).
The method of our investigation is based on the reduction of the parabolic problem to study of the
corresponding parameter-elliptic pseudodifferential problem with a spectral parameter belonging to a
suitable sector of the complex plane. This, approach is applied by many authors, (see, for instance,
works of H. Abels , S. Agmon, M. Agranovich and M. Vishik, R. Denk and L.Volevich, R. Denk and
M. Fairman, G. Grubb, G. Grubb and N. Kokholm , A. Kozhevnikov, T. Krainer and B.-W. Schulze,
and others).
The main technical tool of the present work is the calculus of ψdo′s constructed by H. Kumanogo and R.
k
k
Beals. The classes of considered operators are defined by the functions of the form  1     2  x  ,
where  j , j  1, 2 are weighted basic functions in the sense of H. Kumanogo. Note that the case
1    1    , 2  x  1  x
2
2
(so-called "SG culculus") is considered in the works of M.
Cappiello, T. Gramchev and L. Rodino, E.Schrohe, H. Cordes, Y. Lutsky, M. Ruzhansky and M.
Sugimoto.
34  Mathematics
Field D* pathfinding on weighted triangulated and tetrahedral meshes
Mark N. Berman
Department of Mathematics, Ort Braude College, Karmiel 21982, Israel, E-mail: [email protected]
Keywords: shortest path algorithms, artificial intelligence, graph and tree search strategies, vision and
scene understanding, perceptual reasoning, vector calculus, elementary Euclidean geometry
In May 2013, NASA's nine-year-old Mars Rover, driving along the rim of the Endeavour Crater of
Mars, approached the record for the longest drive on a celestial body other than Earth (Nature, NASA
website). This achievement relates to a basic problem in robotics and medicine: how to compute the
shortest, smoothest path between two points in a complex environment. One approach is provided by
Dijkstra's algorithm (1959), which solves a discrete version of the problem for a graph with weighted
edges. The problem has also been addressed by tessellating the region into polygonal cells (for instance,
a grid of squares) and finding a shortest weighted path traversing the edges. A notable advance in this
direction is the Field D* algorithm due to Ferguson and Stentz (2005), which considers paths that may
pass through the interior of weighted cells. The challenge in this area is to improve the efficiency of
these algorithms. This is especially important in extreme situations, such as the Mars Rover, where
resources of time and energy are limited. In this talk I will discuss recent work in collaboration with
Perkins, Marais and Gain, in which we find analytic solutions to the local minimization problem in two
and three dimensions, using elementary vector methods, thereby refining the Field D* algorithm. I will
also discuss a computational assessment of our refinement against existing schemes.
Mathematics  35
Inequalities for angular derivatives and boundary interpolation
Vladimir Bolotnikov1, Mark Elin2, David Shoikhet3
1
Department of Mathematics, The College of William and Mary, Williamsburg VA 23187-8795, USA, E-mail:
[email protected]
2
3
Keywords: Schur function, angular derivatives, boundary interpolation
The classical Julia-Wolff-Carathéodory theorem asserts that the angular derivative of a holomorphic
self-mapping of the open unit disk (Schur function) at its boundary fixed point is a positive number. In
1982, Cowen and Pommerenke proved that if a Schur function has several boundary regular fixed (or
mutual contact) points, then the angular derivatives at these points are subject to certain inequalities. We
develop a unified approach to establish relations between angular derivatives of Schur functions with a
prescribed (possibly, infinite) collection of either mutual contact points or boundary fixed points. This
approach yields diverse inequalities improving both classical and more recent results. We apply them to
study the Nevanlinna-Pick interpolation problem with boundary data. Our methods lead to fairly explicit
formulas describing the set of solutions.
36  Mathematics
New cases of increasing pursuer capturability by using hybrid dynamics
Valery Y. Glizer1, Vladimir Turetsky2
1
Department of Applied Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
7701669, Fax: 972-4-9901802, E-mail: [email protected]
2
Department of Applied Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
Keywords: interception problem, hybrid dynamics, robust capture zone, capturability
The interception problem is formulated for an engagement of two vehicles: the pursuer and the evader.
The dynamics of each vehicle are described by the vector i  (aimax , i ) , where  i is the time constant
of the first-order controller, and aimax is the maximal lateral acceleration of the pursuer ( i  p ) and the
evader ( i  e ). Modern vehicles can be equipped by the guidance control systems of two types:
aerodynamic control (in the atmosphere), and the thrust vector control (both in the space and in the
atmosphere). This motivates the recent extensions of the interception problem formulations by assuming
the hybrid dynamics of the vehicles. The case of a hybrid dynamics pursuer (a single switch from
max
 p1  (a max
p1 , p1 ) to  p 2  ( a p 2 , p 2 ) ) and a fixed dynamics evader is considered. The robust capture
zone is the set of all initial positions, from which the zero miss distance (capture) is guaranteed by the
pursuer against an arbitrary admissible target control. Previously, it was shown that the pursuer can
increase its robust capture zone by utilizing the hybrid dynamics in the case where for both modes the
max
max
max
max
pursuer is more maneuverable, a pj  ae , and not less agile, a pj /  pj  ae /  e , j  1,2 , than the
evader.
The objective of the presentation is searching all possible cases, where the pursuer's hybrid dynamics
increases the capture zone.
The investigation is carried out in the framework of the Differential Games theory by utilizing explicitly
the game space geometry (decomposition) of a corresponding planar linear pursuit-evasion game with
bounded controls and fixed players' dynamics. In the game solution, the game space is decomposed into
a regular and a singular region. The regular region of the game space is covered by the family of
candidate optimal trajectories. In this region, the optimal strategies of both players are of a "bang-bang"
type and the game value depends on the initial conditions. In the singular region, the optimal strategies
of both players are arbitrary, subject to the constraints, and the game value is constant. The singular
zone can be: (1) unbounded capture zone, (2) bounded capture zone, (3) not capture zone, (4) empty set.
The second dynamic mode necessarily yields the case (1) or the case (2).
Two additional cases of increasing the capture zone are obtained: (i) the pursuer is inferior in
maneuverability and superior in agility in the first dynamic mode, and it is superior in maneuverability
and agility in the second dynamic mode; (ii) in both dynamic modes, the pursuer is inferior in
maneuverability and superior in agility.
All possible combinations of the singular zone properties were verified. It was proved that increasing
the capture zone by using hybrid dynamics is impossible if the first dynamic mode yields the cases (3)
or (4). The pursuer can increase its capture zone if its dynamic modes yield the combinations (1), (1)
(previous result), (2), (1) or (2), (2) (new results), The combination “(1), (2)” needs further
investigation.
Mathematics  37
Indefinite metric spaces and operator linear fractional relations
Victor Khatskevich
Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Fax: 972-9901801, Email: [email protected] , [email protected]
Keywords: strict and bistrict plus-operators, Krein space, linear fractional relation
This is a natural continuation of our previous work in the considered area.
We consider strict and bistrict plus-operators between spaces with indefinite metrics, in particular, Krein
spaces (or J-spaces). We call a plus-operator T in a Krein space strict if T = dA , where d > 0 is
constant and A is a J-expansion, and we call T bistrict if both T and its conjugate operator T* are strict
plus-operators.
We consider operator and geometric sufficient and necessary conditions for a given strict plus-operator
T in a Krein space H to be bistrict as an operator between H and Im T with the induced indefinite
metric.
It is well known that a plus-operator T defines an operator linear fractional relation. In particular, we
consider the special case of linear-fractional transformations. In the case of Hilbert spaces H1 and H2 ,
each linear-fractional transformation of the closed unit ball K of the space L (H1 , H2 ) is of the form
F T ( K )  (T21  T22 K )(T11  T12 K )1
and is generated by the bistrict plus-operator T.
The theory of bistrict plus-operaters and generated linear fractional transformations forms a significant
part of the theory of spaces with indefinite metrics, in particular, Krein spaces. But the much wider class
of strict plus-operaters is an open area for investigation. We hope that our new results on the "similarity"
of a subclass of strict plus-operators, namely the set of all strict plus-operators A, for which the socalled "plus-characteristic" D(A) is non-negative operator, to the subclass of bistrict plus-operators, will
allow developing the theory of strict plus-operators and obtaining new results on generated linear
fractional relations.
We consider applications of our results to the well-known Krein-Phillips problem of invariant subspaces
of special type for sets of plus-operators acting in Krein spaces, to the so-called Koenigs embedding
problem and some other fields of the Operator Theory.
38  Mathematics
Well-posedness of coupled first and second order hyperbolic systems
Lavi Karp
Keywords: well-posedness, non-vacuum Einstein equations
Existence, uniqueness, and well-posedness of quasilinear wave equations that are coupled to first order
symmetric hyperbolic systems are established. Hughes, Kato, and Marsden studied systems consisting
only of second order hyperbolic equations [1]. They proved existence theorems for systems in R n


whose solutions u  t  ,t u  t  lie in the Sobolev space H s+1  H s . In particular, they lowered the
required value of s to s > n / 2 in cases where the coefficients of highest order terms do not involve
derivatives of the unknowns.
We extend their results and obtain the same degree of regularity for coupled first and second order
hyperbolic systems. This result is applied to show short time existence theorems for Cauchy problems
for non-vacuum Einstein equations. This is a joint work with Uwe Brauer.
[1] T.J.R. Hughes, T. Kato and J.E. Marsden, Well-posed quasi-linear second-order hyperbolic systems with
applications to nonlinear elastodynamics and general relativity, Arch. Rational Mech. Anal. 63 (1977), 273-294.
Mathematics  39
Gambler's ruin probability – a general formula
Haggai Katriel
Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, E-mail:
[email protected]
Keywords: Gambler's ruin problem, probability
The Gambler's Ruin problem is a classical probability problem, going back to Pascal and Huygens. In
addition to its intrinsic mathematical interest, it is relevant to many applications in finance and actuarial
theory.
In its simplest form, presented in many elementary probability courses, the problem concerns a gambler
playing a series of games in a casino, where each game leads to winning $1 with probability p and
losing $1 with probability 1  p . The question, given the gambler's initial wealth $M , is to determine
the probability that the gambler is ever ruined, meaning that the gambler's wealth becomes 0. The wellknown answer is: if p 
1
1
, the probability of ruin is 1, while if p  , the probability of ruin is
2
2
M
1 
  1 .
p 
In this work, a general version of the gambler's ruin problem is studied, in which the payoff for each
game is a general integer-valued random variable X , the only restriction being that it is bounded from
below. A general formula for the ruin probability is obtained. This formula is more involved than in the
simplest case presented above, as it is an expression involving the zeros in the unit disk of the
generating function associated to the random variable X .
The general gambler's ruin problem considered here has been studied by others before, but the results
available in the literature are approximate formulas and bounds, rather than an exact formula as
presented in this work.
Publication: Gambler's ruin probability – a general formula, Statistics and Probability Letters, 2013, to
appear.
40  Mathematics
Asymptotic behavior of parabolic type semigroups
Mark Elin1, Fiana Jacobzon2
1
2
Keywords: holomorphic mapping, asymptotic behaviour, one-parameter semigroup, limit curvature
We study the boundary asymptotic behavior of parabolic type semigroups of holomorphic selfmappings of the open unit disk. Namely, we consider semigroups generated by mappings with two
known power terms in their asymptotic expansion at the boundary Denjoy–Wolff point. Exponents in
such expansions are not necessary integers. Hence, we generalize previous results in [1], [2], [3]. In
addition, we present angular characteristics and a generalized limit curvature of semigroup trajectories
at their Denjoy–Wolff point.
[1] M. Elin, S. Reich, D. Shoikhet and F. Jacobzon, Asymptotic behavior of one-parameter semigroups
and rigidity of holomorphic generators, Complex Anal. Oper. Theory (2008), 55-86.
[2] M. Elin, D. Shoikhet and F. Jacobzon, Linearization models for parabolic type semigroups, J.
Nonlinear Convex Anal. (2008), 205-214.
[3] M. Elin and D. Shoikhet, Boundary behavior and rigidity of semigroups of holomorphic mappings,
Anal. Math. Phys. , (2011), 241-258
Mechanical Engineering  41
Plastic deformation mechanisms operating during creep in parent metal and
friction stir welded AZ31B magnesium alloy
Michael Regev1, Stefano Spigarelli2
1
2
Dipartimento di Meccanica, Università Politecnica delle Marche, 60131-Ancona, Italy, E-mail:
[email protected]
Keywords: friction stir welding, magnesium alloys, AZ31
The friction stir welding process (FSW) was developed in the United Kingdom in the early 1990s. Over
the years, FSW proved itself ideal for creating good quality butt joints and lap joints in a number of
materials, especially the family of nonferrous metallic materials including even those that are extremely
difficult to weld by conventional fusion welding processes. During FSW, the frictional heat that is
generated is effectively utilized to facilitate material consolidation and eventual joining with the aid of
an axial pressure. The process is, therefore, a non-fusion welding process.
The aim of this work is to get a better understanding of the deformation mechanisms operating during
creep of parent metal and friction stir welded AZ31B magnesium alloy.
FSW was applied in the current study in order to weld AZ31B-H24 alloy plates. Creep tests were
conducted at 100, 200 and 300°C on both parent material and friction stir welded specimens.
Comprehensive optical and SEM metallographic characterization together with micro hardness tests
were performed on each of the different zones of the welded joint, namely, the parent material, the Heat
Affected Zone (HAZ), the Thermo-Mechanically Affected Zone (TMAZ), and the weld nugget.
The above study revealed that both dynamic recrystallization and mechanical twinning take place during
plastic deformation. High resolution transmission electron microscopy of both welded and non-welded
specimens crept at 1000C revealed that dislocation segments which do not lie on the basal planes exist.
̅
It is therefore assumed that other slip systems are active in addition to the
basal slip
0
systems known to be the only ones active in pure magnesium up to about 180 C. Non-basal slip systems
being operative is advantageous in retarding or even preventing embrittlement of the welded joint as can
be seen from the results obtained. A plastic deformation model, based on the current investigation, will
be presented.
The proposed mechanism is dislocation glide on basal and non-basal planes assisted by twinning and
GBS. Dislocation activity on non-basal planes can explain part of the large elongation-to-fracture due to
additional active slip systems. Twinning contributes by placing new slip systems at a favorable
orientation with respect to the stress axis, while GBS serves as an accommodation mechanism. The
observed grain coarsening in the case of the welded specimens retards GBS, and therefore smaller
elongations-to-fracture were recorded.
42  Mechanical Engineering
A turned trochoidal disturbance on a liquid jet surface
Shalom Sadik1, Felix Kirzhner2, Denis Kramarenko3
1
2
Faculty of Civil and Environmental Engineering, Technion Israel Institute of Technology, Haifa, 32000, Israel,
Tel: 972-4-8293774, Fax: 972-4-8228898, E-mail: [email protected]_
3
Key words: drops, liquid jet, trochoidal function
Mathematical models of spray atomization were mostly developed for serial drop formation. The
Rayleigh linear model was the first to show this development. Subsequent works used nonlinear models
that introduced satellite drops between the main drops but all those were serial. A spray model that
defined peripheral drop production was Zimmels and Sadik analysis, which was based on harmonic
superimposed disturbances. The current work reveals peripheral drop creation without being refined to
superimposed disturbances. The turned trochoid, which is a parametric function, leads to a disturbance
function that is not unique. A non-unique disturbance may lead to peripheral drop production. The
choice of examining a trochoidal disturbance was supported by considerable research on water waves.
The paper goal of this research is to show that a turned trochoidal function disturbance may lead to
peripheral drops production. The resulting model is used to describe that a turned trochoidal disturbance
leads to peripheral drops production on the liquid jet surface without the necessity for superimposed
disturbances.
The Turned Trochoidal Disturbance Function: The turned trochoidal function is received by these
parametric equations:
. where
is the no dimensional
trochoidal parameter, and
and
are dimensional parameters. The choice of the relation between
and
determines the trochoidal figure. The trochoidal disturbance was built by decomposing the
trochoidal function to a Fourier series while every Fourier element received an amplification factor in
accordance with the Rayleigh inviscid jet model. Peripheral drops were received on the jet surface. The
paper shows that all trochoidal disturbance functions—prolate cycloid, cycloid, and curtate cycloid—
have a capability of producing peripheral drops. A limited capability of peripheral drop production is
introduced for the trochoidal curtate cycloid. Produced drops size are reduced to increase the jet velocity
and wave number. Smaller drops are also received by transitioning from the prolate cycloid to the
curtate cycloid disturbance.
Drops may be identified in the crests of the trochoidal surface. The drops increase along the jet surface.
When the jet velocity is reduced the drops tend to merge. When the jet velocity is increased, the drops
show the inverse trend and are produced as discrete drops.
According to expectations, it may be conclude that as the jet velocity increases, discrete and smaller
drops are produced. It is shown and may be concluded that as the wave number increases, the drop size
reduces. In summary, all trochoidal disturbance functions are capable of producing drops. This work
shows that to produce peripheral drops, another kind of disturbance may be offered—the trochoidal
disturbance—without the need for superimposed disturbances.
Performance simulation of a heat pump water heater
Michael Koenig1, Khen Mizrakhi
1
Department of Mechanical Engineering, ORT Braude College, E-mail: [email protected]
Keywords: heat pump, domestic hot water, thermal simulation
Heating of water for domestic use may be performed by a variety of methods. In Israel, utilization of
abundant solar energy is commonplace for hot water production, and in general is sufficient for
domestic needs during the summer. However, in the winter, the majority of water heaters employ
simple, low-efficiency electrical heating elements when solar radiation is insufficient and increased
thermal losses to low ambient temperatures do not allow for the solar collector to meet hot water
demands. In fact, the water heater is a major contributor to high household electricity bills during the
winter months.
High energy efficiency may be achieved by heating the water by means of a heat pump, which operates
at coefficients of performance significantly greater than that of the electrical resistance heating element.
While the complexity - and thus, the initial price - of the active heating system is increased, energy
savings give a return on investment in a period of time significantly less than the life-cycle of the
system.
The current research involves the detailed steady state thermal modeling of a heat pump water heater,
based on first principles of heat transfer and thermodynamics. The achievement of a viable
performance model will aid in optimizing the design of such systems, as well as provide a simulation
tool that can be used to investigate improvements to the heat pump aimed at increasing its coefficient of
performance, especially as the water temperature rises and the ambient temperature decreases. It will
also allow for evaluation and improvement of hybrid operational modes in which both solar and
electrical inputs are active.
Rehabilitation knowledge center at ORT Braude College
Orit Braun Benyamin
Keywords: rehabilitation engineering, disabled population, design
Rehabilitation engineering is now a popular subject taught in many universities. The majority of
courses are part of biomedical engineering curricula. Sometimes they are offered as optional courses as
part of electrical engineering, computer engineering, and mechatronics. Most of these courses involve
multidisciplinary aspects. Thus, emphasis might be put on medical aspects (surgical instrumentation,
medical imaging, orthopedic implants, and biomedical micro-devices). Presented is an introductory
rehabilitation course with a broad agenda: creating mutual cooperation between academia and
community while producing inexpensive tailor-made solutions for everyday problems encountered by
the disabled. This new approach to rehabilitation engineering was initiated at Ort Braude College,
establishing a rehabilitation know-how center in the periphery of Israel.
Our approach differs from other courses at other institutions in the duration of the program and its
emphasis on the design of inexpensive, custom-tailored, yet smart solutions for the disabled population.
The students are exposed to the needs of real clients, with functional problems resulting from their
disabilities. The design phase is followed by the creation of actual products, which are given to the
clients at the end of a one- or two-semester course. This educational phase is critical for the students to
gain engineering expertise while improving the solutions available to the handicapped. The major
objective is to develop universal solutions, whose design and eventually manufactured products are
inherently accessible to people with similar disabilities. These solutions undergo a simplification
process and produce general solutions applicable for a wide range of similar disability groups. The
projects are undertaken by mechanical engineering students, with a duration limited to one or two
academic semesters.
Within two semesters, students who participate in the undergraduate mechanical engineering study
program choose to
 Design a product
 Establish interaction with the disabled population, to determine its specific needs
 Produce the desired product
Finally, the product is examined and tested by the customer. Thus, a systemic process with well-defined
phases is undertaken by the students, allowing them to develop a product and the customer to choose the
preferred solution. This training stage is critical for the students to gain engineering expertise, while
improving the available solutions for the handicapped. At the next phase the disabled client uses the
product, and after an in-depth practical evaluation of it, pinpoints its disadvantages and possible
improvements. This feedback becomes the basic knowledge used as input to the next design course.
Through this course the students recognize the importance of rehabilitation and accessibility for the
handicapped and will hopefully consider these insights in the future when designing new products.
Acknowledgement: This study was supported by a grant from the Council for Higher Education,
Participation of Students and Academy in Community Oriented Projects (rehabilitation biomechanics).
Dynamic mimicking
Avi Weiss1, Gideon Avigad1, Yuri Surkov1, Barak Samina1
1
Keywords: spherical joint, rotational motion generation, dynamics of rigid bodies in magnetic fields
Accessibility for wheelchair users is a major problem, requiring more ramps and elevators to be built. In
other cases, major changes in products should be made. Several specially designed wheelchairs have
been developed. Even though they are specially constructed for climbing stairs and moving on rough
terrain, these wheelchairs are expensive, cumbersome, and scarcely used.
In contrast to these limitations, some robots possess high maneuverability, and are able to climb stairs
and go over obstacles. One way to solve the wheelchair accessibility problem would be to let a robotic
platform carry the wheelchair. However, a major issue is how to control the platform. While an external
assistant could drive the robot, this defeats the purpose of retaining control in the hands of the
handicapped person. An even bigger problem is the inconceivable notion that an untrained user would
control a robotic system, for safety and other reasons. Moreover, controlling a robotic system would be
through a joystick or a driving wheel, with which some handicapped people are unfamiliar, therefore
requiring training and a list of dos and don'ts. A final obstacle to this approach is the fact that
wheelchairs are driven by their users in many different and user-specific interfaces, including joystick,
turning the wheels manually, etc.
We suggest allowing the handicapped person control the robotic platform, thereby enhancing its
maneuverability, independent of the wheelchair type, using the same interface used to operate the
wheelchair.
We allow the wheels of the wheelchair to turn according to the user's commands against a friction
system that maintains the feeling of driving on the ground, even though the wheelchair is secured to the
robotic platform. The friction system serves as a measuring system for capturing the motion of the
wheelchair's wheels. The measured signals are used to determine the kinematics of the wheelchair,
determine the required motion, and translate it to the robot kinematics. This way, the robotic platform
moves as if it were the user's wheelchair, but with enhanced maneuverability and therefore enhanced
accessibility.
The equations for the kinematics and dynamics of the robot were developed and a mimicking system
was constructed. Initial experiments validate that the robot follows the trajectory instructed by the
wheelchair user with good accuracy.
The feasibility of the idea was demonstrated both in simulations and experimentally. Selecting a proper
carrier robot for the wheelchair will commence, and more applications will be explored.
Generation of controlled rolling motion of a cylinder using magnetic fields
Avi Weiss1, Gideon Avigad1, Maor Peretz1
1
Keywords: spherical joint, rotational motion generation, dynamics of rigid bodies in magnetic fields
Spherical joints are kinematic couples that allow three rotational degrees of freedom. While these joints
are commonly used in various applications, they are always passive joints; that is, one may not control
their orientation; rather, the motion of the links attached to the spherical joint sets the orientation of the
joint. The spherical joint simply allows for any rotational motion and does not dictate it. While a
theoretical mechanical solution utilizing a sphere and three omnidirectional wheels exists for the
problem, the requirement for a compact joint that can transfer high torques prevents this solution from
being applicable to a joint. Electromagnetically actuating a sphere was attempted before, but the result
was a possible step motor application that does not allow for continuous control over the motion of the
spherical joint.
The aim of this work is to create an active spherical joint that allows for continuous rotational motion
about any desired axis with no theoretical workspace limitations. The problem is addressed in a few
stages. The basic concept utilizes permanent magnets on the rolling body and electromagnets on the
driving body. In the first stage, the problem is simplified to create a rolling motion without the cylinder
slipping on a flat surface. This issue was not addressed previously, and so this portion in itself is worthy
studying. The scheme of the current profile to be administered to the electromagnets that would generate
continuous motion of the cylinder for benchmarks such as constant speed and constant acceleration are
developed, for the open loop case. This allows for position control of the cylinder. Next, the problem is
expanded to a sphere rolling on a surface, which is essentially a path and trajectory generation problem.
Finally, the flat surface is folded into a sphere and the problem becomes one of a sphere rolling over
another sphere to create the active spherical joint.
The basic setup was selected as N permanent magnets evenly spread on the surface of the cylinder, and
M electro magnets evenly spread on the flat surface. The equations of motion were developed, solved,
and tested with some basic input signals. This is the "forward" problem. However, the real issue is the
"inverse" problem, that is, what should the input to the electromagnets be so that desired motion is
accomplished. The complexity and non-linearity of the problem does not allow for a simple inverse
solution. Thus, a neural network is utilized to obtain an inverse solution. Currently, the problem of
constant speed is resolved, and the solution to the constant acceleration is underway.
From this work, it can be seen that even a simple one-dimensional problem such as rolling a cylinder
over a flat surface does not have a trivial inverse solution, yet it is possible to control such motion.
Future work will include the generation of paths and trajectories for a sphere on a flat surface using a
field of electromagnets.
Committee under grant number 5000.838.1.2-12.
Drilling of composite and metal stack materials with the assistance of low
frequency vibration
Uri Ben-Hanan1, Andrea Stoll2, Steffen Ihlenfeldt 2, Klaus Wolf2
1
2
Fraunhofer IWU, Chemnitz, Germany
Keywords: carbon fiber reinforced plastic, drilling, vibration frequency
Carbon fiber reinforced plastic (CFRP) laminates and metal stacks are growing in use in the aerospace
and automotive industries. To join the stack parts with rivets and/or screws, holes must first be drilled
through the two layers. The holes are drilled with the same drill bit under the same process parameters
and the result is a compromise in the accomplished hole properties. One of the methods to improve
performance is to superimpose low frequency vibrations during the drilling process.
Other publications show that the thrust force and torque while drilling CFRP with superimposed
vibration can be decreased by 20% to 30% compared to conventional drilling. Other published reports
indicate that drilling metal with the addition of low frequency vibrations achieves lower material heating
and improvement in the burr shape while using lower thrust force and torque.
In other investigations a model for predicting the thrust force and the torque in vibration drilling of
CFRP materials was developed. The predicted thrust force and torque under conventional drilling and
under superimposed low frequency vibration showed good agreement with the experimental results.
In the current investigation a special vibration platform actuated by four piezoelectric actuators was
developed. The platform can vibrate in a frequency range of 50 to 200 Hz with vibration amplitude of 015 µm.
During the preliminary drilling tests of the CFRP material a superimposed vibration frequency of 130
Hz and amplitude of 15µm was used. As a result, a reduction of the thrust force compared to the thrust
force measured without vibrations under the same process parameters was observed. The thrust force
decreased with the growing number of holes drilled. Another set of experiments was carried out in
drilling a sandwich (stack) of CFRP and aluminium with different process parameters like rotation
speeds and feed rates, and with different superimposed vibration frequencies and amplitudes. It could be
found that there are different optimal parameters when drilling the CFRP layer and the aluminium layer.
Advances in cognitive neuroscience and optimization theory can inform the
rehabilitation process in developmental disorders:
Production management in the classroom?
Gerry Leisman
Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49086467, Fax: 972-4-9901886, and the National Institute of Brain & Rehabilitation Sciences, Nazareth, Israel, Email: [email protected]
Keywords: cognitive neurosciences, graph theory, rehabilitation
Little of 150 years of research in cognitive neurosciences, human factors engineering, and the
mathematics of production management have found their way into educational policy and certainly not
into the classroom or in the production of educational materials in any meaningful or practical fashion.
Whilst more mundane concepts of timing, sequencing, spatial organization, and Gestalt principles of
perception are well known and applied, the nature of Receiver Operating Characteristics (ROC) and the
responsibility of the sender in that regard, as well as the maintenance of simplistic notions of
developmental brain organization and hemisphericity for language rather than the neurophysiology of
embodied language as an example, still inform the early childhood curriculum. The lecture intends to
overview the science of human physiologic efficiencies in engineering terms applying applications of
graph theory to connectography for examining brain function in real time in an attempt to develop novel
approaches and thinking to classroom-based practice in developmental disabilities and in the viewing of
early childhood education as a rehabilitation discipline.
Physics and Optical Engineering  49
Quantum gravity phenomenology with neutrinos and high energy photons
Dafne Guetta
Department of Physics and Optical Engineering, Ort Braude College; Karmiel 21982, Israel; Tel 972-4-9901835, E-Mail: [email protected]
Keywords: neutrinos, quantum gravity
The aim of this work is to review the main properties of Gamma Ray Bursts (GRBs) as possible sources
of high energy (E>TeV) neutrinos and confirmed sources of high energy (E>GeV) photons.
The work includes a discussion of the possibility of using the data of neutrino telescopes, such as
IceCube and the GeV-photon telescopes, such as Fermi’s LAT, for precision tests of Einstein's Special
Relativity as applied to neutrinos and photons. The focus is on possible departures from Special
Relativity that can be motivated by models of quantum space-time. It is observed that neutrinos which
one would not associate to a GRB, when assuming a classical spacetime picture, may well be GRB
neutrinos if the possibility that Lorentz invariance is broken at very high energies is taken into account.
An outline is presented on how future analyses of neutrino data should be done in order to
systematically test the Lorentz Invariance Violation possibility. In addition the possibility that Lorentz
Invariance Violation might be responsible for the spectral lags that characterize the GeV signal observed
for the remarkable GRB130427A is considered.
A comparison of these features for GRBs at different redshifts provides some encouragement for a
redshift dependence of the effects of the type expected for a quantum-spacetime interpretation, but other
aspects of the analysis appear to invite the interpretation as intrinsic properties of GRBs.
50  Physics and Optical Engineering
Interferometric control over the photo-electric effect:
What is the relative birth place of the electron in the continuum?
Avner Fleischer
Solid State Institute and Physics Department, Technion-Israel Institute of Technology, Haifa 32000, Israel and
Department of Physics and Optical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel ,
[email protected]
Keywords: photoelectric effect, matter waves, quantum control.
In tunnel ionization of atoms by strong laser fields, many photons are absorbed and usually a single
electron is released into the continuum, where it appears at the outer turning point of the tunnel barrier
formed by the combined Coulomb potential that attracts the electron to the ion, and the external
potential imposed by the electromagnetic radiation of the laser field. It is reasonable to assume that a
reduction in the number of photons which participate in the ionization process will shift the appearance
location of the ionized electron towards the origin.
The above hypothesis is verified by studying ionization of atoms by one and two-photon absorption.
By solving the three-dimensional time-dependent Schrödinger equation for a single-electron model of
Argon atom subjected to a continuous (CW) high-frequency laser field, the ionization rate of the atom
could be calculated. The appearance location of the electron in the continuum couldn't be retrieved from
this information alone; some sort of interferometric measurement needs to be carried out. The following
measurement is suggested: add a weak dc field to the high-frequency ionizing laser field. The dc field
doesn't alter the release step of the electrons into the continuum (which is carried out by the highfrequency field alone); it does, however, modify the propagation of the electronic trajectories after they
are released. The dc field forms a triangular barrier from which the right-going trajectories could reflectoff and return to the origin where they interfere with newly born trajectories heading to the left. By
changing the amplitude of the dc field, the nature of interference may be continuously controlled: from
destructive to constructive and vice-versa.
The dependence of the photoionization rate on the amplitude of the weak dc field is shown to be a
simple oscillatory one (where the period of oscillations depends on the dc field amplitude). By
measuring the phase of the oscillations, the average appearance position of the photoionized electron in
the continuum can be retrieved. It is found that while in single-photon ionization the electron appears
(no matter in which direction) almost at the origin (where the ion is placed), shifting the ionization
mechanism to two-photon ionization changes the differential appearance location dramatically. To the
best of our knowledge, these results are the first to reveal an important aspect of the photoelectric effect
which hasn't been addressed so far: where is the photo-electron born in the continuum?
Reinterpretation of the basic axioms founding the principles of
electrodynamics
Ofer Eyal
Department of Physics and Optical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel.
Keywords: dipole electrodynamics
The assumption of point charge as a basic entity can lead to some aesthetic difficulties:
1) No proper description of a point charge in a compact manifold
2) Conservation of charge has to be postulated "by hand"
3) The Green function of the Maxwell equations (described by vector potentials) has no physical
meaning
As in magnetism, we assume that the basic entity of electricity is an electric dipole, that can be created
or annihilated everywhere in space-time. It is clear that any charge/current distribution can be deduced
from a time dependent electric dipole distribution, so our approach is consistent and does not conflict
with the theory based on charges.
In this short lecture we explain how some of the laws of Electromagnetism are obtained by the use of
electric and magnetic dipoles and the analogy between them. Geometric constructions in their
topological properties are involved in obtaining the results.
Noise and controllability: suppression of controllability in large
quantum systems
Shimshon Kallush
Department of Physics and Optical Engineering, Ort Braude College, Karmiel 21982, Israel
Keywords: quantum control, controllability, open quantum systems
A closed quantum system is defined as completely controllable if an arbitrary unitary transformation can
be executed using the available controls. In practice, control fields are a source of unavoidable noise.
Can one design control fields such that the effect of noise is negligible on the time-scale of the
transformation? Complete controllability in practice requires that the effect of noise can be suppressed
for an arbitrary transformation. The present study considers a paradigm of control, where the Liealgebraic structure of the control Hamiltonian is fixed, while the size of the system increases,
determined by the dimension of the Hilbert space representation of the algebra. We show that in general,
for large quantum systems, generic noise in the controls dominates for a typical class of target
transformations i.e., complete controllability is destroyed by the noise. One exception to this case is
classical like transitions where the controlled state remains close to a Generalized Coherent State
throughout the whole dynamics.
Parametric excitation of silicon-on-insulator microcantilever beams by
fringing fields probed with laser Doppler vibrometery
Yoav Linzon1 , Said Mahajna1, Bojan Ilic2, Stella Lulinsky3, Slava Krylo3
1
Department of Physics and Optical Engineering, Ort Braude College, Karmiel 21982, Israel, E-mail:
[email protected]
2
Cornell Nanoscale Science and Technology Facility, Cornell University, Ithaca, NY 14853, USA, E-mail:
[email protected]
3
School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel, E-mail:
[email protected]
Keywords: microcantilevers, laser Doppler vibrometry
Free-standing micro- and nanoelectromechanical system (MEMS and NEMS) devices ﬁnd applications
in various areas due to their small size, low fabrication cost, durable performance, and versatile
suitability for future integration in various complex functional systems.
MEMS and NEMS resonators, often incorporating cantilever structures, have been employed in various
applications with growing complexity, including radio frequency timing devices and sensors for mass
stress and chemical composition detection. Dynamic-mode resonant operation benefits from the
dependence of device spectral parameters on its physical characteristics, the latter of which are extracted
with very high precision.
In this work, we report on the observation of efficient parametric excitation in microcantilevers using
fringing electric fields probed optically by laser Doppler vibrometry (LDV). Figure 1 shows our
cantilever microdevices, consisting of a free-standing cantilever beam and a planar electrode
symmetrically located at both sides of the resonator. Our devices are driven electrostatically via a
network analyzer, and probed via an LDV instrument synchronized in a closed loop with the drive
frequencies of the beam, around the fundamental mode and second harmonic of the mechanical
structure. Future optomechanical sensors could potentially benefit from our novel single-layer device
architecture, where very efficient parametric excitation has been achieved.
Figure 1: (a) Scanning electron micrographs
of fabricated devices; (b) 500 m long and 16
m wide cantilever (beam #1) and its electric
connection; (c) 300 m long and 16 um wide
cantilever (beam #2). Red line illustrates path
of LDV laser probe.
Radiative transfer in stellar atmospheres
Nathan Netzer
Physics and Optical Engineering Dept, ORT Braude College, 21982 Karmiel, Israel, Tel. +972-72-246-3652, Email: [email protected]
Keywords: stellar atmospheres, equation of radiative transfer, dust opacity, spectral line opacity
Stars typically lose mass in a process known as a “stellar wind”. The mechanisms for this are different,
but as the mass is lost, it forms a “circumstellar envelope”, subject to the radiation pressure from the
central star. Calculations of the interaction of the stellar outflow with this radiation have been carried
out in the past, focusing on red giants, where the interaction is with dust, formed from the condensation
of heavy chemical elements.
There is a method of extending the calculations to a wider range of parameters, which will be valid for
more classes of stars. At the moment, this method is applied to spherical stars only. The equations of
radiative transfer are coupled with the dynamical equation, where the radiation field in the stellar
atmosphere is expanded as a Legendre series. Then, if one knows the opacity of the stellar atmosphere
for a wide range of wavelengths, one can calculate the dynamics of the stellar wind. The opacity may
stem from spectral lines or from dust absorption and scattering.
The results hint clearly at an upper possible mass loss rate for stars, where the abundance of carbon
exceeds the one of oxygen.
Future work should treat the case of time-dependent mass loss rates and discuss also non-spherical
systems.
Flux-induced thermoelectric effect
Jorge Berger
Department of Physics and Optical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901991, Fax: 972-4-9883494, E-mail: [email protected]
Keywords: nonequilibrium superconductivity, Nernst effect
It has been known for more than a century that in the presence of a magnetic field and a non-uniform
temperature field, an electric current (or electric voltage) appears, in a direction perpendicular to the
magnetic field and to the temperature gradient. This is known as the Nernst (or Nernst-Ettingshausen)
effect. During the present decade the effect has been intensively studied in superconductors, and a large
Nernst signal has been measured.
In the present study we found that voltage can arise not only from a magnetic field, but also from a
magnetic flux. When a superconducting ring encloses a magnetic flux that is not an integer multiple of
half the quantum of flux Φ0, a voltage arises in the direction perpendicular to the temperature gradient.
This voltage is due to thermal fluctuations. We studied the dependence of this voltage on the
temperature gradient, flux, position, average temperature, BCS coherence length and thermal coherence
length. The largest voltages were obtained for fluxes close to 0.3 Φ 0, average temperatures slightly
below the critical temperature, thermal coherence length of the order of the perimeter of the ring and
BCS coherence length that is not negligible in comparison to the thermal coherence length.
Acknowledgement: This study was supported by a grant from the Israel Science Foundation.
56  Software Engineering
On the location of roots of graph polynomials
Johann A. Makowsky1, Elena V. Ravve2
1
Department of Computer Science, Technion – Israel Institute of Technology, Haifa 32000, Israel, E-mail:
[email protected]
2
Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901902, Fax: 972-4-9901839, E-mail: [email protected]
Keywords: graph polynomials, roots of graph polynomials
A graph G = (V (G);E(G)) is given by the set of vertices V (G) and a symmetric edge-relation E(G). We
denote by n(G) the number of vertices, and by m(G) the number of edges. k(G) denotes the number of
connected components of G. We denote the class of finite graphs by G. Graph polynomials are graph
invariants with values in a polynomial ring, usually Z[X1; : : : ;Xr]. Let P(G;X) be a graph polynomial.
The literature on graph polynomials mostly got its inspiration from the successes in studying the
chromatic polynomial, its many generalizations, and the characteristic polynomial of graphs. In both
cases the roots of graph polynomials are given much attention and are meaningful when these
polynomials model physical reality. A complex number z is a root of a univariate graph polynomial
P(G;X) if there is a graph G such that P(G; z) = 0. It is customary to study the location of the roots of
univariate graph polynomials. Prominent examples, besides the chromatic polynomial, the matching
polynomial, and the characteristic polynomial, are the independence polynomial, the domination
polynomial, and the vertex cover polynomial.
Roots of graph polynomials such as the characteristic polynomial, the chromatic polynomial, the
matching polynomial, and many others are widely studied. In this work we examine to what extent the
location of these roots reflects the graph theoretic properties of the underlying graph.
To restrict our discussion to graph polynomials with combinatorial interpretation we shall only consider
graph polynomials that are definable in second order logic (SOL) in a uniform way. The graph
polynomials that are definable in SOL encompass all the graph polynomials from the literature, but
avoid graph parameters without a natural interpretation. The SOL-definable polynomials are generating
functions where the coefficients are uniformly SOL-definable graph parameters.
Our main result is the following theorem:
Let H be a fixed graph. For every univariate SOL-definable graph polynomial P(G;X) there exist
univariate SOL-definable graph polynomials Qi(G;X); i = 1; 2; 3 d.p. equivalent to P(G;X) such that the
following holds:
(i) For every G all real roots of Q1(G;X) are positive (negative) or the only real root is 0.
(ii) Q2(H;X) = 0, and trivially every complex number is a root of Q2(H;X). In particular the roots of
Q2(G;X) are dense in the complex plane.
(iii) For every G the roots of Q3(G;X) are contained in a disk of constant radius.
Software Engineering  57
Comparable randomness of textual sources
Renata Avros1, Zeev Barzily2, Zeev Volkovich3
1
2
3
Keywords: text randomness, minimal spanning tree, Friedman and Rafsky’s two sample test
In many practical situations it is desirable to decide whether various strings of data were generated by
the same source. For such purposes, tests are formed to compare and contrast the randomness of strings.
In theoretical computer science, randomness is employed in constructing and analyzing algorithms
applied in computational number theory, computational geometry, cryptography, and distributed
computing.
In the current paper we consider the problem of comparing the randomness of two different files. The
difference between the randomness of the two given text files can result, for example, from a difference
in the writing styles. To distinguish between two texts we can draw samples from these texts and
compare them using a probability distance. The distances obtained can actually constitute two sample
test statistics that can be used in the classical univariate procedures. In the current paper we employ the
minimal spanning tree based approach connected to Friedman and Rafsky’s two sample test.
To implement the approach we consider two binary files produced by means of two different sources.
Our purpose is to distinguish between the underlying distributions of these files. To apply the two
sample test we translate the files into numerical sequences, and simulate samples drawn from each file
as samples taken from a high-dimensional vector space. A minimal spanning tree is constructed for the
points obtained by this procedure. In this tree, the number of the edges connecting elements from
different samples is counted. Two texts are associated via comparison of these edge distributions such
that a difference between ones exposes discrepancy of the sources.
To assess the ability of the proposed method, we provide several numerical experiments on various texts
written by numerous authors. The results demonstrate the high potential of the approach in the
comparison of texts. The new approach reveals high capabilities in distinguishing between writing
styles.
Cluster model selection using minimum cost spanning trees
Renata Avros1, Dvora Toledano-Kitai2, Avi Soffer3, Zeev Volkovich4
1
Department of Software Engineering, ORT Braude College,
2
3
4
P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
Keywords: clustering, cluster stability, two sample test
Cluster analysis is a tool for discovering hidden ’groups’ or ’clusters’ in collections of items commonly
described by numerical, linguistic, or structural features. The elements of each cluster are highly similar
to each other in their behaviour (with respect to the given data) and the groups are well separated, as
expected. Cluster model selection, often manifested as determination of the suitable number of clusters,
is a crucial and ill-posed challenge in cluster analysis. Although many approaches have been proposed
for solving this problem, none stands out as being the most effective for a general-purpose model
selection problem.
In the current talk we present a new viewpoint to the cluster model selection problem, which is based on
the minimum cost spanning tree approach. Our method is founded on a modified version of the
Friedman and Rafsky two sample test, which takes into account the edge lengths.
Our approach presented here is based on the perception that samples drawn from the source population
have to be well mixed in the clusters if the model is correctly chosen. Consequently, their clustered
occurrences can be interpreted as independent realizations of the same random variable. A natural tool
to measure the realizations’ closeness is provided by simple probability metrics or two sample test
multivariate statistics. In this talk we propose a method for cluster model selection, which is based on
the minimum cost spanning tree approach. In our modified version of the Friedman-Rafsky test, the
statistic uses not only the number of edges connecting points from different samples in a minimal
spanning tree constructed for each of the clusters, but also the edge lengths. Our model selection method
is summarized in a short meta-algorithm, which is then adopted in the clustering process aiming to
estimate the “true” number of clusters.
To evaluate the ability of our proposed methodology, we carried out several numerical experiments on
synthetic and real datasets. In each experiment, the computations are performed on a substantial number
of samples. Empirical distributions of the maximal score value obtained for the test statistics are formed
for several possible numbers of clusters with the purpose of determining the “true” quantity of clusters
by means of the one most suitably concentrated distribution.
The proposed novel method demonstrates high capabilities in handling the problem consisting of
detection of the true number of clusters.
Graph partition approaches based on ladder connected components
Zakharia Frenkel1, Ahuva Mu'alem2, Avi Soffer3, Zeev Volkovich4
1
Department of Software Engineering, ORT
9901902, E-mail: [email protected]
2
3
4
Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
Keywords: protein–protein interaction, graph partition, ladder connected components
Protein–protein interaction (PPI) networks are important sources of information relating to the
principles of cellular processes and functions. It has been shown before that a clustering protein
interaction network is an effective approach for identifying protein complexes and functional modules.
However, traditional clustering algorithms have difficulty in identifying these modules, largely due to
the presence of noisy false positive interactions as well as specific topological challenges in the
network.
The research aimed to propose methods for developing a new clustering algorithm that focuses on the
connected components and works well on a dense enough network. Several existing algorithms based
on the connectivity measure have various disadvantages. Some of the known algorithms do not perform
well in a dense network, meaning they generate a small number of large clusters. This work proposes
methods to overcome the problem.
The purpose of this work is to develop approaches to graph clustering for PPI networks based on
connected components, to improve the performance of the circles k-ladder algorithm and other related
algorithms in dense networks.
The main purpose of the algorithm is to divide a given network into a large number of small enough
clusters. In contrast to the classic approach, this proposed method deals with certain structural elements
connections rather than simple vertex connections. One of the strong features of the algorithm is the
ability to identify clusters that are not necessarily highly inter-connected, meaning that it does not
resemble a clique.
The new algorithm has been developed is based on the following approaches to modernization of the kladder algorithm: (1) Structural method, which is based on defining a structure and the way the
structures should connect; (2) Group similarity method, which is not based on a specific structure, but
requires a group to fulfill specific conditions (for example, the Jaccard similarity method); and (3)
Multilevel method, which expands the first method by defining the structure and the way two structures
connect to each other, and after identifying the clusters this method continues by replacing every
structure by a vertex and running the algorithm again. The algorithm executes on large data sets that
include hundreds of thousands of vertices, yet runs in a reasonable time and uses memory efficiently.
The first application of PPI network clustering via connected components, based on the Jaccard
similarity method at different thresholds, has revealed the presence of one large connected component,
in many folds larger than other clusters. A graduate increase of the similarity threshold smoothly breaks
this component down into very small (1-5) groups. We propose that this newly observed property of PPI
networks can be responsible for scale-free organization of these graphs described earlier.
The new approaches for a PPI network partition based on connected components appears to be very
fruitful and able to bring a new understanding of internal organization of these networks.
Adaptive language modeling for word prediction
Orly Yahalom
Keywords: language modeling, word prediction, autocomplete, topic modeling, keystroke savings
Word prediction (or “text prediction”) is a feature provided by many web browsers, e-mail
programs, search engine interfaces, etc. Text prediction involves the program predicting a word that the
user wants to type without the user actually typing it completely. This feature is effective when it is easy
to predict the word being typed based on those already typed, and based on a data base. Text prediction
speeds up human-computer interactions in environments to which it is well suited.
We consider two types of words separately: Stop words are very common words such as "the" and "to".
The rest of the words are called fringe words. While the frequency of stop words is assumed to be
independent of the topic of the text, that of fringe words may vary significantly among different topics.
We propose a novel language adaptive model model, whose main principles draw from Keith Trnka
(2008):
a. Prior Probability (Topic Identification): Identifying the relevant topics according to recently
typed fringe words and using an existing data base.
b. Posterior Probability (Topic Application): Higher weight (priority) is assigned to fringe words
related to the current topic(s).
The main innovations in our model are as follows:
a. We allow the user to characterize a topic by uploading text files and applying topic tags to them.
Therefore we set the similarity to a certain topic directly, rather than through applying a topic
clustering algorithm.
b. To increase the expected number of keystrokes saved, we consider word lengths, in addition to
word frequencies. That is, a word weight is calculated as the product of its length and its
estimated frequency. This principle is expanded to the suffixes of the words: we suggest them to
the user while they are typing, and update their weights accordingly.
We test the efficiency of our model by applying it to various texts and computing the percentage of
keystroke savings.
Molecular dynamics study of double-stranded DNA molecule folding
Zakharia Frenkel1, Avi Soffer 2
1
Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901902, E-mail: [email protected]
2
Keywords: DNA folding, molecular dynamics simulations
Molecular dynamics simulations are used to predict a molecule’s behavior in terms of structural
changes. A molecule, or any other atomic structure, is never motionless. The physical and chemical
forces that are exerted on each atom by its neighbors cause it to move, thus changing the molecular
structure. This research focuses on DNA molecules. DNA molecules have a distinct shape of a doublehelix, consisting of a sugar band – which acts as the backbone of the structures – and pairs of
nucleotides that are attached to the sugar band. Knowledge of the 3D configuration of a DNA sequence
is essential for understanding its biological functions.
The aim of this work is to develop a computerized 3D simulation and visualization environment that can
be used to study and analyze the movements in DNA sequences that change their structure. This
approach takes into account the intra-molecular and intermolecular interactions as has been done in
other simulation models, while considering the vibrations in the bonds between the atoms, which is
neglected in many other simulations.
The goal is accomplished by building a 3D simulation that models the changes of a DNA molecule,
from its initial, relaxed, state, through the time period defined by the user. The simulation starts by
modeling the DNA structure while taking all of the physical and chemical properties of the molecule’s
atoms into consideration. After the initial configuration is ready, the simulation begins to calculate all
the forces exerted between all atoms. Using very small time-steps, all the forces are summed for each
iteration, the acceleration is calculated, and then the velocity and position are integrated. After the
positions become available, the atoms are aligned accordingly, and the next iteration begins.
During the simulation process, output files containing the atom positions are created and stored. These
files are used as frames for the 3D visualization. Because the time-step used is very small and the
changes between two adjacent time-steps are insignificant, the frames are created every user-defined
number of iterations so that there is a visible change in the molecules’ structure. The use of Nordsieck's
algorithm on the differential equations that are obtained using the ENUF method allows completing the
computations in a realistic amount of time.
The visualization approach allows the user to set parameters such as refresh rate, arbitrarily halt the
process, run backwards and forwards, and also to manipulate the viewing angle freely on each axis.
The developed simulation/visualization tool was tested against several DNA sequences to assess their
curving nature. The mechanism was able to accurately simulate a molecule's motion in a vacuum. The
simulation consumes reasonable computing resources and executes at satisfactory rates of performance.
The 3D simulation and visualization approach presented here is used to study the natural movements of
DNA sequences (such as the nucleosome positioning pattern). Using this mechanism results in saved
time and resources required in real laboratory experiments. Furthermore, it enables calculations and
analysis beyond the capabilities in a real lab environment.
Simple repeat fossils in protein coding sequences
Zakharia Frenkel1, Zeev Barzily2, Zeev Volkovich3, Edward Trifonov4
1
2
3
4
Genome Diversity Center, Institute of Evolution, University of Haifa, Mount Carmel, Haifa 31905, Israel, Tel:
Keywords: triplet expansions, text segmentation, dynamic programming, protein structure
The phenomenon of the triplet expansion is well known as molecular pathology causing
neurodegenerative diseases. The ability of tandem repeats to increase the number of repetitions is a
fundamental property of DNA. It is widely accepted that this property is associated with slippage during
the DNA replication. It was shown that tandem repeating sequences, especially triplet repeats, play a
very important role in genome formation. This result led to the formulation of the following hypothesis:
most of the genomic sequences evolved through never-ending acts of tandem repeat expansions with
subsequent accumulation of changes. We have recently estimated that in the E. coli K-12 genome, about
35.5% of gene sequences can be detectably traced to original simple repeat ancestors.
The purpose of this work is to investigate the ancient triplet-expanded regions in protein coding
sequences to discover connections between the original simple repeat ancestors and the protein ternary.
In many cases, the powerlessness of the remaining signal causes the mapping of the formerly ideally
repeating segments to be a complicated problem. We apply a clustering algorithm for rigorous mapping
of the original, now hidden, triplet expansions in genomic sequence. This mapping task can be
considered analogous to the case of a well-developed text segmentation procedure aiming to divide a
text into homogeneous segments, so that each segment deals with a particular subject while contiguous
segments deal with different subjects. Several methods are applicable here, but we use a quick linear
time algorithm based on the dynamic programming methodology. To investigate the connection
between the original simple repeat ancestors and the protein structure we use a database of proteins with
known structures accompanied by DNA sequence encoding.
The initial application of the clustering algorithm to the protein coding sequences reveals the sharp
differences in similarity to repeats between different codon positions. The highest similarity was in the
third position, the next highest was in the first, and the lowest was in the central position. This result is
in accord with the well-known functional importance of positions in codons. The second position
determines amino acid polarity (hydrophobicity), and cannot be uniformly positioned along the
sequence. The least important is the third position. It is usually redundant, so that there is no need to
change it. Therefore, traces of the simple repeat ancestor, which are kept by the sequence, are strongly
dependent on the selective pressure affecting the DNA sequence.
The proposed new point of view on a genetic sequence as a collection of mutually modified tandem
repeats, together with application of a text segmentation algorithm, provide an innovative approach to
the analysis of protein coding sequences.
Teaching and Learning  63
Students’ misunderstandings in project design activities
Elena Trotskovsky1, Nissim Sabag2
1
Department of Electric and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
2
Keywords: misunderstandings, digital electronics, project design
The presentation presents the results of research that analyzed student misunderstandings in project
design activities.
The research aimed to characterize misunderstandings and misconceptions in project design.
Twenty electronic engineering students participated in the study. Group A (eight students) carried out a
learning project in a digital electronics lab and Group B (12 students) performed a final design project in
industry. A qualitative research methodology was applied. The research tools were observations of
Group A’s activities, interviews, and document analysis of all participants. Group A students were
required to design a small electronic system complying with a verbal description and technical
requirements. They developed a block diagram and implemented electronic circuits through a
simulation program. Group B students solved a wide range of problems that are typical for electronics
engineers. In their final project these students went through all the stages in design and implementation
of new devices: selection of components, calculation, drawing, simulation, fabrication, testing, and
integrating the designed device into the whole system.
Misunderstandings in block diagram functionality and real life problems were identified as typical for
Group A students. Iterative thinking helped Group B students to overcome their misunderstandings.
Strong motivation based on a real need and personal responsibility challenged the latter group of
students to conquer their misunderstandings and arrive at complete design systems.
64  Teaching and Learning
Financial planning for the engineering student
David Pundak1, Arie Maharshak2
1
Web-Learning Unit, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901843, Fax: 972-49901886. Engineering School, Kinneret College. E-mail: [email protected]
2
President of ORT Braude Engineering College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901750, Fax:
Keywords: financial planning, funding academic study, student loans, student employment
Recent research at the ORT Braude Engineering College (Maharshak & Pundak, 2012) demonstrates
why students in Israel are reluctant to take bank loans to fund academic studies. Findings indicated that
55% of the students dislike being exposed to financial risk and 73% avoid taking loans, thus preferring
to work during their studies, even though most believe that work may harm their ability to complete
their studies in the usual four-year time frame. The mean length of studies for college graduates is four
and a half years; in some departments the mean length of studies extends to five and a half years. Due to
these results, the “Investing in Education” program was established.
Students participating in the program will (a) improve academic results, (b) complete studies in four
years, and (c) improve their chances of employment right after graduation.
In early 2013, students in years 2-3 with satisfactory academic achievements were offered low interest
loans, repayable after graduation with a comfortable payment scheme. The program was marketed on
notice boards, the Internet, and in a one-day seminar discussing advantages of loans versus paid
employment during studies. A dean’s committee selected 49 suitable participants out of 67 candidates
who registered for the program. They signed a contract detailing their obligations during and after the
program. Students complying with the program goals can take the program loans even in years 3 and 4.
Student Obligations: (a) paid employment during studies restricted to 30 hours per month,
(b) investing most of their time in studies with a commitment to improve average grades each year, and
(c) regular loan repayment after graduation in line with bank’s terms.
Participants completed a questionnaire relating to academic achievements and motives for loan-taking.
Students accepted for the program underwent interviews to deepen understanding of their loan-taking
decision. Following the 2013 exams program, participants will complete a summarizing questionnaire,
and achievements will be compared with previous college grades.
Research Questions: 1. How does the program impact participants’ academic achievements? 2. To
what extent does the program assist students to comply with the recommended learning program? 3.
How does the program influence students’ time management during studies? 4. How does the program
influence student perceptions of the college?
Initial results will be presented at the conference.
Using lab experiments in electric circuits to promote achievements in
mathematics
Nissim Sabag1, Elena Trotskovsky2
1
2
Keywords: active learning, constructivism, enhancing learning
Some mathematicians believe that mathematics learning should be abstract, and that mathematics
should not be contaminated by practical examples from different fields of life. In contrast, others think
that combining practical examples from various disciplines can contribute to the understanding of
mathematics.
The research presented here examines the effect of integrating examples from the discipline of electrical
and electronics engineering into the mathematics studies of students learning about complex numbers.
A quantitative methodology included a real field experiment from the group of “True Experimental
Design”, and the kind of Posttest – Only Control Design. A class of 35 students was randomly divided
into experimental and control groups. Their average grades in mathematics in eleventh and twelfth
grades were compared to verify that there was no difference in learning achievements between the
groups prior to studying the complex numbers unit. Both groups listened to the same mathematics
lectures. The control group practiced in the traditional way using examples and exercises from
mathematics textbooks, while the experimental group performed laboratory experiments in electrical
circuits, which required the use of complex numbers to calculate the voltages across the circuit
components. The two groups had the same amount of practice time; their home assignments and final
test were identical. Home exercises were classified according to PST (problem solving taxonomy)
levels. Four months later, the students were tested again on complex numbers to see how much they
remembered of what they had learned.
The prior average grades were 74.89 for the experimental group and 74.61 for the control group.
Further, the students completed an Abstract Reasoning test (AR) to test their analytical thinking skill.
The average score of the experimental group was 87.35 and that of the control group was 92.35,
indicating 5 points in favor of the control group. The final examination, immediately after studying the
complex numbers unit, showed a small, but not significant gap between the two groups, with the
experimental group’s grades slightly higher than the control group. In a test given four months later, the
experimental group score 61.07 in average compared with an average grade of 44.75 for the members of
the control group, 16 points higher on average for the experimental group—a significant difference.
This disparity in favor of the experimental group is statistically significant, and can be explained as the
contribution of performing laboratory experiments that made the experimental group members engage
in active learning. This activity in turn heightened these students’ knowledge construction, compared to
the control group’s members whose learning was passive. As a result, the latter group’s acquired fragile
knowledge did not survive for long.
Teachers' work context:
Components that support or inhibit the implementation of innovations
Yael Furman Shaharabani
Teaching & General Studies Depts., ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901975, Fax: 972-4-9901738, E-mail: [email protected]
Keywords: professional development, work context, science education
Professional development (PD) in-service programs for teachers are a customary means to implement
innovations in curriculum and practice. Although studies of programs are widespread, there is limited
research of long-term effects of PD on science teacher development. Long-term PD for junior high
school (grade 7-9) science teachers were held in Israel in the 1990s as part of a comprehensive national
science education reform.
The main goal of the study was to examine the long-term effect of extended PD in the past on science
teachers' professional development. This presentation will focus on the relation of the teachers' work
context and their ongoing implementation of innovations that were introduced in past PD.
This study used the cross-case method to study each teacher individually, and to search for differences
and commonalities within the group. The research encompassed 33 grade 7-9 teachers who participated
in three sustained in-service PDs roughly ten years previously. Ten teachers were chosen for a profound
case study that included a set of in-depth interviews. Each interviewee also presented documents such as
worksheets, notes, and examples of student work related to the PD. The verbal data was inductively
analyzed to identify themes. The documents were used to support, validate, and exemplify the interview
data.
The teachers’ teaching context varied considerably. We found seven context components related to the
implementation of the PD's innovations: class size and teaching time; students' characteristics; learning
environment; science teachers' team work; management support; school culture; and the ministry of
education's policy. Each teacher had an exclusive combination of components. The teachers emphasized
the importance of the science teachers' team work and management support, to the continuous
implementation of the PD's innovations.
The teachers differed in their level of implementation, the change in their conceptions of teaching and
learning, and in their reaction to their teaching context. The level of continuous implementation
matched the work context of most of the teachers. The supportive context was related to continuous use
of PD's innovations, while inhibitory context was related to a reduction in of implementation over time.
Only a small group of teachers, who changed their conceptions considerably during the PD, found ways
of working with inhibitory context, and used context-derived opportunities to continue and advance the
innovations’ implementation.
Our findings suggest that major changes in science education require a supportive school context to
enable continuous innovation and development of practice. A less supportive environment might lead to
a reduction in the teachers' innovative practices.
Acknowledgement: This study was supported by a PhD scholarship from the Technion – Israel Institute
of Technology.
"From good to excellent"- Coaching for success
Miri Shacham1, Rivka Weizer-Biton2
1
Teaching & General Studies Depts., Teaching and Learning Center, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901724, Fax: 972-4-9901738, E-mail:, [email protected]
2
Prof. Ephraim Katzir Department of Biotechnology Engineering, Teaching and Learning Center, ORT Braude
College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901901, Fax: 972-4-9901839, E-mail: :
[email protected]
Keywords: coaching for success, personal and academic development
This year the Teaching and Learning Center initiated a new program for students at ORT Braude
College. The program, called "From good to excellent", has two goals: on the personal level, to promote
students' academic achievements and self-efficacy; and at the college level, to promote and empower
students with a high level of academic achievement.
The students were assigned to the program in an assessment center managed by the psychologists of the
Teaching and Learning Center. The coaching process included a two-hour meeting between a group of
three or four students and their coach every week during one semester. The main issues discussed
during the coaching process included personal and academic success and excellence, student's vision,
goals, work plans, and coping with difficulties.
In addition to the coaching meetings, the students participated in workshops for a year, dealing with
topics such as applying for engineering jobs, empowerment, stress management, effective presentation,
and conflict management.
The program was accompanied by longitudinal research.
The research focuses on the students’ perceptions regarding the contribution of the coaching program to
their personal and academic development. In addition, the study aimed to explore the possible impact of
being a coach on the professional development of the college lecturers.
During the second semester of this academic year, sixteen students participated in the "coaching for
success" program run by ORT Braude College lecturers who had participated in a training course for
"Group Coachers diploma", with special focus on promoting students' aspirations and achievements.
Questionnaires were conducted with 15 students who participated in the program and four lecturers who
were the coachs for these students.
In this presentation we will present our initial findings regarding the contribution of the program to the
students and the lecturers.
Engineers as second-career teachers: The perceived contribution of
engineering education and career to teaching
Yael Furman Shaharabani1, Miri Shacham1, Orna Muller1
1
Teaching & General Studies Depts., ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-49901975, Fax: 972-4-9901738, E-mail: [email protected], [email protected], [email protected]
Keywords: career change, second-career teachers, engineering education
Due to a shortage of high-school teachers in fields including science, technology, and mathematics, the
Ministry of Education has initiated special programs for training second-career teachers. A secondcareer teacher often brings a rich personal and professional life experience to teaching. Career changers
believe their age and experience provide them with skills that are immediately transferable to the
classroom, including communication skills, the ability to manage multiple projects simultaneously, a
highly developed work ethic, analytic thinking, and more.
Previous studies have reported on the varied reasons that motivate people to switch to a career in
teaching: a desire to "pay back" society for the opportunities given to them, a more "family friendly"
career, and "meaningful work"; and recognition that teaching offers opportunities for personal growth,
creativity, autonomy, and employment security.
This study aims to explore the possible contribution of education and a previous career in engineering to
teaching as a second career. A deeper understanding of the unique skills and qualities that engineers
bring with them to school may help utilize these skills for the promotion of science and technology
education. This study also aims to explore the engineers' reasons for a change of career to teaching. The
results may contribute to the adaptation of pre-service teaching programs to meet engineers' needs in
their transition to teaching.
This pilot research explores the transition to teaching of thirty engineers who are studying in a special
pre-service training program of the Ministry of Education, conducted by ORT Braude College in
cooperation with the Kibbutzim College.
The first stage of this study includes open-ended questionnaires inquiring about the engineers'
backgrounds, their motivation for becoming teachers, and their perceptions and expectations; the second
stage includes interviews with eight to ten engineers from this group, to clarify and elaborate on
significant issues concerning the career switch, identified through questionnaires' analysis.
Preliminary results derived from the questionnaires and interviews' analysis will be presented at the
conference.
Acknowledgement: This study is supported by a grant from the MOFET Institute.
Misconceptions in electronics design using simulation
Nissim Sabag1, Elena Trotskovsky2
1
2
Department of Electric and Electronics Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Keywords: misunderstandings, misconceptions, simulation
Lifelong learning is one characteristic that is very much needed by engineers. To ensure that learning is
effective, engineering students should start their education while free of misconceptions. Ridding
students of their misconceptions is one of the tasks of engineering educators. Once ingrained,
misconceptions are very difficult to cast off. Consequently, helping students overcome misconceptions
during the studying period is very important because it can contribute in the maturation of novice
engineers and assist them in their future careers. Simulation is an efficient tool to help engineers and
students with electronic circuit design and testing. Nevertheless, circuits do not function in simulation
exactly as in real life.
The article presents examples showing the potential danger of misconceptions generated when using
simulation.
In the current study we interviewed three teachers and 12 students, and observed students that were
implementing their electronic circuit design using simulation.
The results show that using simulation without implementing the circuit with real components leaves
students with the impression of realization of the circuit. They tend to believe that the simulation results
are the same as real life results.
Since the students are actively involved in learning, they strongly believe that their misunderstanding is
a true fact; therefore the misunderstanding may become a misconception.
Mathematical knowledge for effective teaching and learning:
The case of four algorithms
Ira Raveh
Department of Teaching and General Studies, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
Keywords: mathematical knowledge for teaching, standard algorithms, the four arithmetic operations
Recent studies deal with teachers’ mathematical knowledge for teaching that can most effectively
support learning. This knowledge differs from the mathematical knowledge of people who are not
engaged in teaching and is characterized, among other things, by the interconnections between subjects
taught. The studies describing teachers’ knowledge do not provide a sufficiently wide picture regarding
the components of mathematical knowledge required for teaching different subjects.
The goal of the study is to identify -first, theoretically- the core components of mathematical knowledge
for teaching the standard algorithms of the four basic arithmetic operations, and then to empirically
examine the feasibility of the framework by applying it to the design of tasks having the potential to
capture variations in the teachers' knowledge.
The research sample included 46 mathematics teachers. The main data were collected during an
intervention lasting eight meetings, in a national professional development workshop for teachers, in
two parallel groups, and in a series of semi-structured interviews (about 20 hours) with the teachers,
conducted about two months after the end of the intervention. All the meetings and interviews were
recorded using audio recorders and fully transcribed. The data were inductively analyzed. The analysis
was conducted in a spiral way. At each stage, the components of the teachers' responses to the various
questions and tasks that were relevant to the research questions were identified and categorized. The
wide range of data sources warranted the cross-referencing and triangulation of the data.
The study proposes a reference framework for characterizing school teachers’ mathematical knowledge
of the standard algorithms of the four basic arithmetic operations. The study proposes a method of
developing operational criteria for identifying various knowledge components, which also serves for
constructing mathematical tasks in a chosen context. This process can be generalized, and it provides
guidelines for constructing knowledge components for other mathematical subjects.
On the practical level, the study indicates ways to deepen the mathematical knowledge when teaching
the four algorithms, and focuses on the characteristics of unique tasks with a particularly high potential
to promote this knowledge. The findings help in formulating recommendations regarding teaching
methods for this subject within teacher professional development settings. In addition, the findings help
define the mathematical contents related to teaching this subject, along with a recommendation to
include non-standard tasks stressing the interconnections between the algorithms and their underlying
mathematical principles.
Acknowledgements: The research thesis was done under the supervision of Prof. Boris Koichu, Prof.
Orit Zaslavsky, and Dr. Irit Peled. This study was supported by the Technion – Israel Institute of
Technology.
Attitudes of engineering instructors toward “active learning”
David Pundak1, Miri Shacham2, Orit Herscovitz3
1
Web-Learning Unit, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901843, Fax: 972-49901886, E-mail: [email protected]
2
Department of Teaching, Ort Braude Engineering College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-526660321, Fax: 972-4-9901886, E-mail: [email protected]
3
The Department of Education in Technology and Science, Technion, Haifa, Israel, 32000, E-mail:
[email protected]
Keywords: active learning, active instructors, e-learning, student involvement, evaluation
Instruction in higher education has developed significantly over the past two decades, influenced by two
trends: promotion of active learning methods and integration of web technology in e-Learning. Many
studies have found that active teaching improves students' success, involvement and thinking skills.
Nevertheless, internationally, most instructors maintain traditional teaching methods. A research tool –
Active Instruction Tendency (AIT) – questionnaire, developed based on the experience of “active
instructors,” exposed the transitions they had undergone. Following a review of the literature and an
examination of the attitudes of “active instructors,” six key areas were identified that may characterize
the lecturer's tendency to adopt active learning techniques. Using the AIT questionnaire, in 2009 we
examined the attitudes of 135 instructors in three institutions of higher education in Israel, with regard
to active learning (Pundak et.al 2010).
Active Learning and Higher Thinking Levels: One of the most significant aims of the active learning
approach is to develop high level thinking skills. Students are asked to solve problems according to the
scientific method. They collect, analyze, interpret and represent data, and relying on this procedure, they
design a system, component, or process to meet desired needs (Etkina & Van Heuvelen, 2001).
According to Bloom's taxonomy of learning domains (1956), there are three domains of educational
activities: (1) The Cognitive Domain, which involves knowledge and the development of intellectual
and mental skills; (2) The Affective Domain, which describes the way we face things emotionally, such
as feelings, appreciation, values, enthusiasm, attitudes, and motivations; and (3) The Psychomotor
Domain, which involves physical movement, coordination, and use of motor skills. According to the
active instruction approach, team-work in small groups plays a crucial part in the lesson. Practicing
exercises in problem-solving leads students to pay attention to their thinking strategies. The new
knowledge that they develop is organized, analyzed, applied, and evaluated through thinking procedures
(Dori & Belcher, 2005).
In 2013 we administered the AIT questionnaire again in four institutions of higher education in Israel.
During the last four years a significant attitude toward active learning of engineering instructors was
found. Their attitudes were compared with the attitudes of instructors who have taught in active learning
environments. In all six identified instruction areas, significant differences were found between attitudes
of “active instructors” and other instructors.
72  Author Index
Author Index
Abu-Salih, S.
Alperstein, D.
Altevogt, P.
Avigad, G.
Avros, R.
Ayali, A.
Azhari, R.
Barzily, Z.
Ben-Hanan, U.
Berger, J.
Berman, M.
Bolotnikov, V.
Bonshtein, I.
Boxma, O.
Braun-Benyamin, O.
Bretz, N.
Couronne, T.
Dahan, M.
Dawas, A.
Dosoretz, C.
Eichler, S.
Elin, M.
Eyal, O.
Faran, D.
Fleischer, A.
Florescu, R.
Frenkel, Z.
Fried, Y.
Furman-Shaharabani, Y.
Gavish, N.
Gladshtein, M.
Glizer, V.
Golani, I.
Gontmacher, G.
Gregor, P.
Groysman, A.
Guetta, D.
Haimov, Y.
Hardy, A.
Harris, N.
Herer, Y.
4
2
8
45,46
57,58
3
10,14
56,62
3,47
55
34
35
14
23
44
8
5
12
13
13
11
32,35,40
51
28
50
19,20
59,61,62
27
66,68
29
18
36
10,16
19
9
6
49
1
21
9
25
Herscovitz, O.
Huppertz, B.
Ihlenfeldt, S.
Ilic, B.
Jacobzon, F.
Kallush, S.
Kaplan, C.
Kapon, E.
Karp, L.
Katriel, H.
Khatskevich, V.
Kirzhner, F.
Kirzner, V.
Knani, D.
Koenig, M.
Korenblat, K.
Kosa, G.
Kosolapov, S.
Kramarenko, D.
Kroll, E.
Krylo, S.
Langbeheim, H.
Leisman, G.
Levenshtein, M.
Linzon, Y.
Lulinsky, S.
Lutzky, Y.
Mahajna, S.
Maharshak, A.
Makowsky, J.A.
Maoz, M.
Marmor, Y.N.
Mizrakhi, K.
Mu'alem, A.
Muller, O.
Naseraldin, H.
Netzer, N.
Panitz, D.
Peretz, H.
Peretz, M.
Perry, D.
71
8
47
53
40
52
9
21
38
39
37
42
5
2
43
5
3
17
42
14
53
15
48
32
53
53
33
53
64
56
11
30
43
59
68
25,29
54
11
27
46
23
Pundak, D.
Raveh, I.
Ravid, R.
Ravve, E.V.
Regev, M.
Sabag, N.
Saban, A.
Sabbah, I.
Sadik, S.
Samina, B.
Sammar, M.
Segal, E.
Shacham, M.
Shamir, A.
Shechtman, R.
Shnits, B.
Shoikhet, D.
Shteeman, V.
Siwetz, M.
Smith, E.
Soffer, A.
Spigarelli, S.
Stoll, A.
Surkov, Y.
Tadmor, H.
Tahan, M.
Toledano-Kitai, D.
Toubi, A.
Trifonov, E.
Trotskovsky, E.
Turetsky, V.
Volkovich, Z.
Weinberg, L.
Weiss, A.
Weitz, I.S.
Weizer-Biton, R.
Wolf, K.
Yahalom, O.
Zaytsev, V.
64,71
70
23
56
41
63,65,69
22
1,13
42
45
8
11
67,68,70
10,16
20
24
32,35
21
8
21
58,59,61
41
47
45
16
26
58
12
62
63,65,69
36
5,57,58,59,62
7
3,45,46
11
67
47
60
3

The 9 Interdisciplinary Research Conference ORT Braude College

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