Students` Intenrational Research Report vol 5 2012-13

Transcription

National Institute of Technology Durgapur, INDIA
Students’ International Research Projects
Technical Report 2012-2013
Volume 5
[Blank page]
From Director’s Desk
I am pleased to note that, like the last four years, we are publishing the “Students’
International Research Projects; Technical Report 2012-2013; Volume 5” this year too.
This report presents an overview of the research activities of our students during
internship and presentation in international conferences abroad.
Over the last few years, National Institute of Technology Durgapur has been trying to
initiate the students to active research early. They are supervised by the faculty members
of the Institute and are financially supported by the Institute for their research visits to
conferences in India and abroad and for research internship abroad. This has exposed
them to the research activities being carried out in the premier universities in the world
and encouraged them to interact directly with the most eminent researchers around the
globe.
I wish the authors will pursue research and innovation in their professional life.
Professor T. Kumar
Director
National Institute of Technology Durgapur
[blank page]
AUTHORS
Avishek Dey
Abhisek Mukhopadhyay
Anurag Bhattacharyya
Arkaprava Chaudhuri
Debjani Chakraborty
Kumar Gaurav Singh
Manisha De
Ria Mishra
Shivani Bansal
Soumya Sarkar
Souransu Nandi
Sudipto Majumder
AUTHORS
Vivek Kumar Singh
Anish Singhania
Ankit Bhardwaj
Arup Kanti Kole
Bikash Choudhury
Debanjana Baksi
Divyam Saran
Arambam James Singh
Pritha Das
Saupayan Mazumdar
Contents
Title
Author
Page
No.
A COMPARATIVE STUDY OF MANGANESE OXIDE/GRAPHENE
COMPOSITES AS SUPERCAPACITOR ELECTRODES
Avishek Dey
1
INVESTIGATING THE FEASIBILITY OF A TRAVELLING-WAVE
CHOPPER FOR THE CLEAN SEPARATION OF 10 MHZ
BUNCHES AT HIE-ISOLDE
Abhisek
Mukhopadhyay
3
DESIGN MODIFICATION AND ANALYSIS OF SAA3
STRUCTURE
5
AN ALLOHEXAPLOID BRASSICA POPULATION DERIVED
FROM CROSSES BETWEEN ALLOTETRAPLOID SPECIES
SHOWS A RANGE OF FERTILITY AND REGULAR
SEGREGATION OF ALLELES
Arkaprava Chaudhuri
7
ELECTROCHEMICAL IMPEDANCE MODELLING OF
SODIUM ION BATTERIES
Debjani Chakraborty
9
EFFECTS OF RADIATION AND RADIATION CALCULATION
AT CMS CAVERN
Kumar Gaurav Singh
11
DEVELOPMENT OF A TOOL TO CONTROL POWER
DISTRIBUTION UNIT (PDU) FOR DETECTOR CONTROL
SYSTEMS
Manisha De
13
EFFECTS OF ARSENIC EXPOSURE ON REGULATION OF
ANGIOGENESIS BY VEGF-A AND VEGFR-2 IN ZEBRAFISH
Ria Mishra
15
PERFORMANCE ANALYSIS OF HMPID (HIGH MOMENTUM
PARTICLE IDENTIFIER DETECTOR) OF ALICE (A LARGE ION
COLLIDER EXPERIMENT)
Shivani Bansal
17
RESISTIVE SWITCHING OF TRANSPARENT COMPLEX
OXIDE RERAM FILMS
Soumya Sarkar
19
DESIGN AND DEVELOPMENT OF PRINTED CIRCUIT BOARDS
FOR DIFFERENT CONTROLLERS OF A POWERED ORTHOSIS
Souransu Nandi
21
MODELLING OF THE ELECTRICAL EQUIVALENT OF
RESISTIVE PLATE CHAMBERS
A MULTI-AGENT TEST BED FOR MICROGRID CONTROL
Sudipto Majumder
23
Vivek Kumar Singh
25
RESEARCH INTERNSHIP:
CONFERENCES:
SEMANTIC WEB-BASED E-COUNSELING SYSTEM
Anish Singhania
27
MODELLING OF MULTIAGENT BASED RAILWAY SYSTEM
USING BDI LOGIC
Ankit Bhardwaj
29
EFFECT OF ANNEALING ON YELLOW ORANGE
PHOTOLUMINESCENCE EMISSION OF UNCAPPED Mn2+
DOPED ZnS QUANTUM DOTS SYNTHESIZED BY SIMPLE
CHEMICAL METHOD
Arup Kanti Kole
31
A FAMILY OF FLEXIBLE OFFSET-TIME BASED WAVELENGTH
SCHEDULERS FOR OBS EDGE-NODES
Bikash Choudhury
33
CHAOTIC BLOCK ENCRYPTION WITH POSITION
PERMUTATION
Debanjana Baksi
35
QCA MULTIPLEXER BASED DESIGN OF REVERSIBLE ALU
Divyam Saran
37
AGENT BASED TASK SPECIfiC TEAM FORMATION FOR
EFFECTIVE DISTRIBUTED DECISION MAKING
Arambam James
Singh
39
SUPPLIER SELECTION IN RISK ENVIRONMENT: FUZZY
INTERVAL TYPE-2 TOPSIS METHOD
Pritha Das
41
2-Π CROSSTALK NOISE MODEL FOR DEEP SUBMICRON
VLSI GLOBAL RC INTERCONNECTS
Saupayan Mazumdar
43
A COMPARATIVE STUDY OF MANGANESE OXIDE/GRAPHENE
COMPOSITES AS SUPERCAPACITOR ELECTRODES
Avishek Dey
M. Tech student, Department of Physics
Email id: [email protected]
Department of Engineering and Innovation
The Open University, Walton Hall, Milton Keynes, MK7 6AA , UK
March 18 – May 10, 2013
Abstract
Composites of reduced graphene oxide
/Manganese oxide at three different
oxidation states of Manganese were
successfully synthesized through facile
solution based chemical methods. The
morphology and microstructure of the as
synthesized
composites
were
characterized by Field emission scanning
electron
microscopy,
Raman
spectroscopy, X-ray photo electron
spectroscopy
and
High
resolution
transmission electron microscopy.
Introduction
Carbon-based materials have been
researched extensively as electrodes in
electrical energy storage devices such as
supercapacitors and batteries, owing to a
unique combination of properties such as
high surface area, lightweight, good
electrical conductivity, compatibility with
other materials, and controlled pore size
distribution [1-3]. The advent of new forms
of carbon materials such as high quality
graphene sheets (single layer to a few
layers) with superior electrical properties
have allowed for the development of new
engineered carbons for energy storage
[4,5]. Owing to their large in-plane
conductivities graphene films are expected
to play a crucial role in the development of
electrodes for a variety of energy
applications such as photo-voltaics [6] and
supercapacitors [7]. These materials have
recently been used in super capacitor
devices to replace conventional carbon
electrodes and have shown very good
performance [8]. On the other hand
transition metal oxides, in particular,
manganese oxides are well known for
their use in supercapacitor [9]. In view of
the above the present work focuses on the
synthesis
and
characterization
of
grapheme and Manganese Oxide for
applications in energy storage.
Experimental
Graphene oxide was synthesized using
Hummers
method
[10].
MnO2/GO
composite was synthesized by refluxing
Graphene oxide and KMnO4 at 160ºC in
presence of citric acid. Mn2O3/GO
composite
was
synthesized
by
ultrasonicating Graphene oxide and
KMnO4 in presence of ethylene glycol and
then reducing with hydrazine.Mn3O4/GO
composite
was
synthesized
by
hydrothermal reaction of Graphene oxide
and Mn(AC)2 at 200 ºC.
Results and Discussion
The morphologies of the resulting
products were characterized using a
scanning electron microscopy (SEM,
ZEISS SUPRA 55VP FEGSEM, 20 keV)
attached with an energy-dispersive X-ray
analysis
(EDAX)
and
transmission
electron microscopy (HRTEM; JEM JEOL2100,
200
keV)
The
elemental
composition was characterized by X-ray
photoelectron spectroscopy
(Al Kα
radiation at 12 kV and 12 mA).
Fig (a), (b), (c) shows the SEM images of
the composites. From images it can be
depicted that the multiple layers of
graphene are stacked in the form of
flakes. Fig (b) shows the cluster formation
of the MnO2 particles on the graphene
sheets. Fig (c) shows less agglomeration
on the Mn2O3 particles on the graphene
sheet. This may be due to the proper
1 dispersion during the synthesis of the
composite. In the case of Mn3O4 the
particle density is very less in comparison
to MnO2. The above figures (d), (e),(f)
shows the EDS spectrum of the different
composites. The inset in each figure
shows the relative concentration of the
elements in the composites.
¾ Transmission electron microscopy
¾ Scanning Electron Microscopy
Conclusion and Future Work
Above results confirm the formation of
different Manganese oxide / graphene
composites.
The
electrochemical
properties of these composites are
currently being studied using cyclic
voltammetry
and
electrochemical
impedance spectroscopy.
(a)
(d)
(b)
(e)
(c)
(f)
Fig (a),(b),(c) shows the SEM images of
the composites. From images it can be
depicted that the multiple layers of
graphene are stacked in the form of
flakes. Fig (b) shows the cluster formation
of the MnO2 particles on the graphene
sheets. Fig (c) shows less agglomeration
on the Mn2O3 particles on the graphene
sheet. This may be due to the proper
dispersion during the synthesis of the
composite. In the case of Mn3O4 the
particle density is very less in comparison
to MnO2. The above figures (d), (e), (f)
shows the EDS spectrum of the different
composites. The inset in each figure
shows the relative concentration of the
elements in the composites.
The HRTEM images (g), (h), (i) reveal the
lattice orientation of α-MnO2, Mn2O3,
Mn3O4 and the carbon atoms of the
graphene sheets respectively [11].
(g)
(h)
(i)
References:
[1] Simon, P.; Gogotsi, Y. Nat. Mater.
2008, 7, 845.
[2] Zhang, L. L.; Zhao, X. S. Chem.
Soc. Rev. 2009, 38, 2520
[3] Chmiola, J.; Yushin, G.; Gogotsi,
Y.; Portet, C.; Simon, P.; Taberna,
P. L. Science 2006, 313, 1760
[4] Srivastava, A.; Galande, C.; Ci, L.;
Song, L.; Rai,
C.; Jariwala,
D.;Kelly, K. F.; Ajayan, P. M.
Chem. Mater. 2010, 22, 3457
[5] Biswas, S.; Drzal, L. T. ACS Appl.
Mater.
Interfaces
2010,2,
2293
[6] Eda, G.; Fanchini, G.; Chhowalla,
M. Nat
Nanotechnol.2008, 3, 270
[7] Kinoshita,
K.
Carbon:
Electrochemical
and
Physiochemical Properties; 1988,
Wiley- Interscience: New York.
[8] Liu, C.; Yu, Z.; Neff, D.; Zhamu, A.;
Jang, B. Z. Nano Lett. 2010, 10,
4863
[9] Dillon, A. C. Chem. Rev. 2010,
110, 6856
[10]
Hummers WS, Offeman
RE
(1958)
J
Am
Chem Soc 80:1339.
[11]
K Erickson, R Erni, Z Lee,
N Alem, W Gannett, A Zettl ; Adv.
Matter ,2011, 4467
2 INVESTIGATING THE FEASIBILITY OF A TRAVELLING-WAVE
CHOPPER FOR THE CLEAN SEPARATION OF 10 MHZ BUNCHES
AT HIE-ISOLDE
Abhisek Mukhopadhyay
Fourth year B. Tech. student, Department of Electronics & Communication Engg
CERN, Geneva
May 11 – July 10, 2013
Abstract
The feasibility of a travelling wave type
chopper at HIE-ISOLDE was investigated
using a simple model comprising a chain
of synchronised capacitors pulsed at highvoltage. Even with a relatively large
transverse aperture of 30mm, it appears
feasible to remove the satellite bunches
spaced at 75mm without significantly
perturbing the main bunch. We estimate
that for a chopping voltage of 1.2 kV a
string of 20 capacitors is required to
impart the required deflection of 4 mrad to
beams with A:q = 4:5 and the mechanical
length of the system can be kept under 0.5
m. The deflection imparted on the main
pulse is . 1% of that received by the
discarded satellite bunches and the
transverse emittance growth of the beam
is small if the rise/fall times are kept below
5 ns.
Introduction
In order to provide the requested 10MHz
beam frequency at HIE-ISOLDE it is
proposed
to
pre-bunch
into
the
101.28MHz REX-ISOLDE RFQ using an
external multi-harmonic buncher (MHB)
operatingat a sub-harmonic ten times
lower in frequency. As a consequence of
the imperfect bunching efficiency of the
MHB-RFQ system (80%) some of the ‘outof-phase’ particles entering the RFQ will
be bunched into adjacent buckets outside
of the main buckets spaced at a frequency
of 10.128 MHz. A chopper structure is
required to attain a clean separation of the
10MHz bunches by removing the satellite
bunches from the bunch train.
Theory / Model
The system initially considered consists of
a single parallel plate capacitor. in a
direction transverse to the beam axis; we
neglect
the
other
smaller
field
components. This field deflects the
unwanted satellite bunches onto a slit
placed a distance downstream of the
chopper, while the nominal bunches (the
main bunches that are not kicked) are
transmitted through the slit.
Then we scale the system up to the level
of a higher number of capacitors and
introduce structures that make this
feasible.
The feasibility is achieved by introducing
ground planes for effective shielding
between two capacitor plates. This is
necessary as in their absence the
capacitor plates might influence each
other leading to undesirable transient
performance. In this study we do not focus
on the transient performance and assume
steady state behaviour.
This is primarily a first order study in which
we later take into account the complicated
scenarios and try solving more problems.
But we are convinced that first order study
is important to understand the system.
3 Experimental
Conclusion
We simulated a simple parallel-plate
capacitor using CST EM Studio 2012
assuming
that
the
quasi
static
approximation is valid for the low
frequencies. Fourier decompositions of
trapezoidal pulse signals indicate that the
most dominant frequency components are
below 100 MHz, where the wavelength is
3m. The wavelengths of the timedependent components of the electric field
are therefore much larger than the scale of
their spatial variation and to a good
approximation the Helmholtz equation can
be reduced to the static Laplace equation.
The feasibility of cleanly separating the
main 10.128MHz bunches from the
101.28MHz satellite bunches with a
travelling-wave type chopper at HIEISOLDE was demonstrated using a model
comprising a chain of synchronised
capacitors pulsed at high-voltage and by
employing the quasi-static approximation
for the rf fields. Even with a relatively large
transverse aperture of 30mm it is possible
to remove the satellite bunches that are
separated by d = 75mm without
significantly perturbing the main pulse. We
estimate that for a chopping voltage of 1.2
kV a string of 20 capacitors is required to
impart a deflection of 4 mrad to beams
with A:q = 4:5 and the mechanical length
of the system can be kept under 0.5 m.
The deflection of the main pulse is .1% of
that received by the discarded satellite
bunches and the transverse emittance
growth of the beam is small if the rise/fall
times are kept below 5 ns (the sleep-time
of the plates should be 5 ns).
We do the required calculations on the
basis of a single capacitor, then we scale
the structure up to meet the specification.
We arrive at some basic design guidelines
for the simplified chopper consisting of an
array of independently powered parallelplate capacitors in the table.
The table clearly shows that we can attain
the given specifications and have a
structure well within the desired range of
0.5m.
Length of the plates (l) [mm]
12
Aperture (separation of the
plates),d [mm]
30
Distance to ground planes d2
[mm]
2
Separation of shielding planes
[mm]
5
Excitation voltage [kV]
1.2
No. of capacitors, N
20
Length of chopper, L_Struct [m] <0.5
ratio
<1%
Rise, fall time (tau)[ns]
<5
Sleep-time (T) [ns]
5 to 10
4 DESIGN MODIFICATION AND ANALYSIS OF SAA3 STRUCTURE
B. Tech. third year B. Tech. student, Department of Mechanical Engineering
National Institute of Technology, Durgapur, India
ALICE PH/DT
European Organization for Nuclear Research (CERN), Geneva, Switzerland
May - July, 2013
Abstract
The following report describes the tasks
performed during the summer internship at
CERN, Geneva, which are listed below:
1) Modification of the SAA3 extension
using CATIA V5
2) Analysis of the SAA3 beams, using
ANSYS WORKBENCH 14.5 and
determine the safety of the beams
under the proposed loading using
different modelling approaches.
3) Analysis of the SAA3 support
structure
using
ANSYS
WORKBENCH 14.5 and determine
the safety of the structure under the
intended loading condition using
different modelling approaches.
4) Determine the feasibility and the
safety of the SAA3 wall connection by
doing analysis of the connecting bolts
The proposed extension is shown below:
The final SAA3 structure should be as below:
Introduction
The main beam pipe in ALICE detector is
surrounded by a wall of steel blocks for
filtering the beam background detected by
ALICE. These steel blocks along with the
anti-seismic frame and the support structure
together make the SAA3.
Here the mass of the blocks along with the
anti-seismic frame is approximately 52
tonnes.It has been proposed to extend the
SAA3 structure for further beam filtering and
increased data accuracy by adding another
set of blocks and beams to the existing
structure. The newer blocks are dimensioned
as l=800mm, b=400mm and h= 400mm. total
mass of the proposed structure is 35tonnes.
.
5 Theory / Model
Experimental
DESIGN MODIFICATION:
Proposed design:
The experiments carried out were in ANSYS
software. The modelled structure was then
exposed to variety of loading conditions to
generate data on its behaviour and
deformation so as to determine its safety and
reliability. The concepts used were those of
uniformly loaded beam and beam subjected
to concentrated loads.
Final design:
Minimum yield stress value is 355 MPa.
Taking, Factor of safety =1.35
We have the maximum equivalent stress =
1.35* 103.64= 139.914 MPa
So we can safely conclude from the above
analysis that the structure is SAFE by a
factor of 2.53.
Conclusion
The SAA3 structure has been analysed in
many possible ways to determine its safety
as well as its reliability. The structure has
been found to be safe as discussed before. I
have tried to include the modelling
approaches in very detailed manner, showing
all the necessary steps.
6 AN ALLOHEXAPLOID BRASSICA POPULATION DERIVED FROM
CROSSES BETWEEN ALLOTETRAPLOID SPECIES SHOWS A RANGE
OF FERTILITY AND REGULAR SEGREGATION OF ALLELES
Arkaprava Chaudhuri
Fourth year B. Tech. student, Department of Biotechnology
School of Agriculture and Food Science, ARC CILR
The University of Queensland, Brisbane, Australia
December 10, 2012 – February 15, 2013
Abstract
There is a useful allelic contribution from all
three of the Brassica genomes present in the
cultivated diploid (2n=AA,2n=BB, 2n=CC)
and allotetraploid (2n=AABB, 2n=AACC,
2n=BBCC) crop species (canola, cabbage,
mustard) in the production of allohexaploid
Brassica (2n=AABBCC) which is added with
its
potential
for
hybrid
heterosis.
Characterisation of a population of putative
allohexaploids derived from a hybrid parent
from the novel cross (B.napus X B.carinata)
X B.juncea was done by using techniques
like single nucleotide polymorphism (SNP)
,molecular marker assay, flow cytometry and
Fluorescent in-situ hybridisation (FISH).
Introduction
The Brassica genus contains more number of
cultivated crop species of any plant genus.
Six major crop species are B. rapa (Chinese
cabbage, turnip), B. oleracea (cabbage,
cauliflower, broccoli), B. nigra (black
mustard), B. napus (canola, rapeseed), B.
juncea (Indian mustard, leaf mustard) and B.
carinata (Ethiopian mustard). Among these
species there is an unique correlation: the
progenitor diploid species B. rapa (2n = AA),
B. oleracea (2n = CC) and B. nigra (2n = BB)
gave rise to allotetraploid species B. juncea
(2n = AABB), B. napus (2n = AACC) and B.
carinata (2n = BBCC) through pairwise
crosses .However the strange fact is the
absence of natural occurrence of any
allohexaploid
species
(2n=AABBCC),
although each pair of genome coexists in the
allotetraploid(2n=AABB,AACC,BBCC).
Hybridization and polyploidy are potent force
s that allow evolutionary development of new
species against their parent species.
Hence it is rightfully evident that generation
of artificial allohexaploid of Brassica can lead
to development of modern crop species
which can tolerate a wide range of climatic
conditions and also demonstrate outbreeding
enhancement of functions over the already
available Brassica crops.
Experimental
1. Pollen Viabilities:
Dissected anthers obtained from flowers (all
viable samples were used) were placed on
slides, added with 1% acetic-acid carmine
solution. The solution basically apart from
acting as a dye also prevents pollens from
getting disoriented. A cover slip was then
placed over the petals of flowers and slowly
placed to allow release of pollen grains,
which was then viewed under Bright field
microscope( 150X –Nikon E400).
Oval
shaped,
stained
pollens
were
considered as viable and shrivelled nonstained ones non-viable. A minimum of
around 300 viable pollens were counted from
two different flowers obtained from each
viable samples.
7 2. Sporad Observation:
Buds were collected in the morning and
placed in 6:3:1 ethanol :chloroform :acetic
acid solution and was incubated for about 24
hours at room temperature before being
transferred to 50% ethanol at 4 ºC for storage.
Some 60 individuals in the SP population
was studied for sporads production. On an
average of 96.1% tetrads, 1.1 % triads ,2.1%
dyads and 1.6% monads. Samples
containing sporads with more than 4 nuclei
was however found to be less than 0.01%.
Anthers were dissected out of the buds and
squeezed with tweezers to let the sporads be
released on the microscope slides which was
then dyed with 1% acetic acid-carmine
solution. The number of sporads from one to
six nucleic post meiosis was counted for all
the viable populations for at least 500
sporads per sample.
Therefore, we could not find any major
correlation between the pollen viability and
DNA content although we did find some
association among the pollen viability and
seed set in the subset of SP population which
was used for DNA content observation
Graph Demonstrating Self Pollinated Seed Set : A major issue faced by the establishment of
an allohexaploid species may be the lack of
selection pressure in early generations for
euploid,
un-rearranged
chromosome
complements. In our study, there was no
relationship between the fertility in the SP
generation and the missing chromosome
fragments
Furthermore, the results of our analysis
support the successful utilization of FISH for
investigation of chromosome complements in
cytogenetically complex hybrids.
Conclusion
Pollen viabilities data was collected from
around 120 samples .Major difference was
however not found for samples grown at
three different geographical locations. Pollen
viabilities varied from 0-83% with an average
of 42%.Some 10 individuals were found to be
male sterile (8.3%).
8 ELECTROCHEMICAL IMPEDANCE MODELLING OF
SODIUM ION BATTERIES
Debjani Chakraborty
Fourth year B. Tech. student, Department of Electrical Engineering,
National Institute of Technology Durgapur, India
[email protected]
TUM CREATE, RP1 (Battery group), Singapore
May 14- July 12, 2013
Abstract:
Energy storage in utility power grids has
been known for many years. It is receiving
more attention recently due to the
proliferation of intermittent renewable energy
resources. The basic requirement for large
scale storage system is ultra long life cycle,
high power capability and low cost. Sodium
ion battery (NIB) is a promising alternative to
the aforementioned technology. Various tests
like cyclic voltammetry, electrochemical
impedance spectroscopy (EIS), raman
spectroscopy, etc are performed for battery’s
performance data analysis. In the project, a
technique is developed to study the electrical
circuit (model) associated with the chemical
environment with the help of the EIS data.
Introduction:
The entrance of LIBs into the high energy
fields, such as electric vehicles and grid
storage puts into question the availability of
readily accessible lithium in the environment.
Sodium ion battery (NIB) is a promising
alternative to the aforementioned technology.
Sodium metal’s alkaline chemistry is quite
similar to that of lithium, just that the size of
sodium ion is bigger that lithium ion which
sometimes affects the storage and cyclic
ability of NIBs. Currently there are many
groups of Battery researchers around the
globe who are working on high performance,
durable electrode material based on the
porous 3D NASICON framework, Na 3 V 2
(PO 4 ) 3 /C. After the assembly of the coin
cell with the electrodes and electrolyte, the
cell is made to undergo tests conducted by a
computer controlled ARBIN battery tester.
Electrochemical Impedance Spectroscopy is
a test conducted by ARBIN, in which a purely
sinusoidal voltage is applied across the cell
to study the variation of impedance in
frequency domain. From these results and
studies the analogy of an electric circuit to a
chemical system is presented with the use of
Laplace transform to construct the transfer
function of the system by studying the nyquist
and the bode plots obtained from system
data. Thus the electric circuit of the
impedance model of such a system is
constructed with the help of MATLAB
program as a tool. The developed
electrochemical impedance model is at a
rudimentary stage. It is viable only for
studying sodium vanadium phosphate
batteries. To make it applicable to other
electrode materials, further studies have to
be performed to study the interrelation of
different
parameters
of
the
model.
Researchers are developing such models for
fuel cells as well.
3D NASICON structure of Na3V2(PO4)3
9 Theory:
A purely sinusoidal voltage is applied across
the cell.
E = Em sin (ωt) I = Im sin (ωt-Ψ)
Z = E/I Z = Zm (cos (Ψ)+j sin (Ψ)) = real(Z)+
j.img(Z)
Here the red circles show the real EIS data
obtained from ARBIN. Blue line is the
MATLAB fitting of the nyquist plot and the
green line is the MATLAB fitting of diffusion
region.
Experimental:
Results:
The equation describing complete fitting and
hence the complete transfer function
designed for the system is:
Z(s) = R s +
+
+
Rct1 = A/B, Cdl1 = 1/A, Rct2 = C/D,
Cdl2 = 1/C
The straight line (diffusion region in the
nyquist plot) refers to the Warburg
impedance(Zw).
Z w = σω-0.5+j* σω-0.5
s = σ + j*ω
Where σ refers to diffusion constant and ω
refers to frequency. Zw is modeled as a
constant phase element.
Conclusion:
This is the electrical circuit representing the
model. Here Q means the double layer
capacitance (Cdl) which is not an ideal
capacitance. Here Q is a constant phase
element. For which the impedance Z =
1/Q(jω)n. For ideal capacitance n tends to 1.
Rs refers to the solution resistance which
comes into the picture due to movement of
sodium ions in the electrolyte. Rct refers to
charge transfer resistance which occurs at
the electrode-electrolyte interface.
The transfer function describing the EIS
model for NIB is designed successfully. In the
model there is a nexus between the
constants involved which is present in the
form of a jacobian, which if studied properly
can unravel pathways for designing such
transfer functions for a wide plethora of
battery system as well as fuel cells which can
be very useful for providing accurate
literature for further research into details of
the systems.
Acknowledgement:
Mr. Chad Mason (Supervisor), Research
Associate (RA), RP1, TUM CREATE Dr. Irina
Gocheva(Co-supervisor), RA, RP1 TUM
CREATE , Prof. Harry Hoster, Principal
Investigator(PI),
RP1,
TUM
CREATE
Singapore.
10 EFFECTS OF RADIATION AND RADIATION CALCULATION
AT CMS CAVERN
Kumar Gaurav Singh
European Organisation for Nuclear Research (CERN) Geneva, Switzerland
May 13 – July 10, 2013
Abstract
Theory
The main objective of this project was to
know about radiological quantities and units,
including some basic facts about radioactivity
and the biological effects of radiation; risk of
radiation to occupationally exposed workers
and radiation calculation through CMS
cavern.
The amount of a radiation dose depends on
the intensity and energy of the radiation, the
exposure time, the area exposed and the
depth of energy deposition.
Introduction
Whether the source of radiation is natural or
man-made, whether it is a small dose of
radiation or a large dose, there will be some
biological effects. There are two mechanisms
by which radiation ultimately affects cellsdirect effect and indirect effect. Also, not all
cells are equally sensitive to radiation. Those
which are actively reproducing are more
sensitive than those which are not. Biological
effects depend on the rate as well as the total
dose delivered to the tissue, like fractionation
reduces biological damage considerably.
Progressive stages of the biological
consequences of exposure to radiation begin
with damage to complex molecules and
continue through effects at the sub-cellular,
cell and tissue levels and, for sufficiently high
doses, to the ultimate survival of the
organism and to possible genetic changes
affecting entire animal population. Radiation
protection involves three basic measurestime, distance and shielding.
1. Absorbed dose
2. Effective dose
3. Equivalent dose
Various quantities that have been introduced
to specify the dose received and the
biological effectiveness of a given dose are:
Detrimental effects of radiation can be either
‘somatic’ or ‘hereditary’. The effective dose
limits have been recommended by the ICRP
(International Commission on Radiological
Protection) for three categories of peopleradiation workers, trainees and general public
to protect them from the harmful effects of
radiation.
Experimental
The whole CMS experiment or detector is
located in an underground cavern whose
diameter is 15m and length is 21.5m.
Suppose, the proton-proton collision takes
place at the centre of the detector and hence,
any radiation activity which follows, is at its
peak at the centre of the detector, as if any
radioactive products are released after the
collision they have their origin at the centre of
the CMS detector. The workers are assumed
to be standing parallel to the detector and at
a distance of 2m away from the cavern.
11 The occupational workers can use measuring
instruments for radiation protection which are
both ‘installed’ and portable. The installed
instruments include area radiation monitors,
Gamma interlock monitors, personnel exit
monitors, and airborne particulate monitors.
Cross section of the CMS detector
Using distance equation we calculated the
dose rate at points E, F, G, and H. We also
calculate the dose rate at the point where
workers are standing. For any other points,
we have to calculate the distance by using
spherical coordinate system and then
calculate the dose rate. The value of dose
obtained has to be less than 20 mSv/y as
prescribed by ICRP for radiation workers.
Conclusion
Distance is a good way of minimising dose
when radiation is involved. Dosimeter- a
device worn by the worker which measures
the absorbed dose should be used strictly.
Practical radiation measurement is essential
in evaluating the effectiveness of protection
measures, and in assessing the radiation
dose likely to be received by the individuals.
We found that the dose rate at these points
was 0.02 times the radiation at the source of
radiation. Similarly, the dose rate faced by
the worker standing at a distance of 2m from
the detector was 0.01 times the radiation at
the source of radiation. Since the value of
calculated dose rate was less than the
prescribed value, the worker was safe to
work under the given circumstances.
12 DEVELOPMENT OF A TOOL TO CONTROL POWER DISTRIBUTION UNIT
(PDU) FOR DETECTOR CONTROL SYSTEMS
Manisha De
Fourth year B. Tech. student, Department of Electronics & Communication Engineering
European Organisation of Nuclear Research (CERN), Geneva
May 12- July 11, 2013
Abstract
A PDU(power distribution unit) facilitates the
handling of large no. of devices at the same
time through a single pc.A PDU when
installed in a computer gives a webpage
display of all its power outlets through an xml
data sheet.A simple approach to monitor the
PDU outlets by building a graphical interface
in the WINCC software led to the
development of the ALIPDU package.It
displays two user defined panels which
shows the current status of all the PDU
outlets and thereby provides the options to
monitor the same.
Introduction
In today's accelerating world every task
demands the handling of large number of
devices. A single device does no good.
Keeping pace with such proliferating
demands we have designed a simple tool.
But first we need to be acquainted with a few
terms before we come to know how to use
the tool.
• Power Distribution Unit:-A PDU is a
controlling medium. It can have 8 or
16 or 24 power outlets depending on
the type. Real devices such as
laptops, monitors, printers , etc can
be connected to these outlets and
each of these devices are operated
via s single master pc to which the
PDU is installed.
•
The 'AliPdu' tool:- But to control the
PDU we need some sort of an user
interface in the master PC. To
accomplish this we have designed
some panels in Wincc and then
created a tool comprising of all these
panels. This tool is what we call the
'AliPdu' tool.
Experimental
EXPERIMENTAL:-The AliPdu tool is used in
the following way:
• Create an empty project in Wincc by
going to the Wincc OA Project
Administrator.
• Go to the graphical interface (GEDI)
and install the framework installation
tool. Once installed now install
the 'AliPdu' tool. The project will
automatically restart.
• The 'AliPdu' tool has two user defined
panels named as the New PDU panel
and the PDU outlets panel.
• First open the New Pdu panel, enter
the name of the PDU you are working
with and click the 'Create Pdu'
button.
• This action automatically starts
updating the current status of the
PDU outlets from the xml data sheet
and
consequently displays
them on the PDU outlets panel. The
user now has clear view of which
device connected to which power
outlet is switched off or rebooting etc.
• The PDU outlets panel further
provides the scope for monitoring
each of the outlets simply through the
panel
itself
like
adjusting
a
computer's
screen
resolution,
cancelling the job of a printer etc.
• The PDU outlets panel is selfequipped with a security alert. If
somehow the PDU malfunctions or it
gets disconnected from the pc due to
some reason, the panel turns red to
13 visually alert the user to take some
steps.
Conclusion
'AliPdu' has been essentially built as a tool
for the detector control systems .But it is an
easy and simple tool that finds its use almost
in every sphere of technical world today, be it
in control industries or large experimental
laboratories where there is a need for
controlling numerous machines or devices
and manual effort on each individual speck
fails. This tool makes the job much more
simpler and faster thereby also increasing the
efficiency.
Fig: Creating the panels
Fig: Status of the devices connected to the outlet.
14 EFFECTS OF ARSENIC EXPOSURE ON REGULATION OF
ANGIOGENESIS BY VEGF-A AND VEGFR-2 IN ZEBRAFISH
Ria Mishra
Indiana University, Bloomington, IN, USA
May 30 – July 25, 2013
Abstract
Angiogenesis is the sprouting of new blood
vessels from existing blood vessels.
Zebrafish intersegmental vessel (ISV)
growth is widely used to study angiogenesis
and to screen drugs and toxins that perturb
angiogenesis. Gene expression in zebrafish
ISV development is similar to that of other
vertebrates, including humans, making
things learned from the zebrafish model
relevant to understanding angiogenesis in
humans. Our hypothesis was that Arsenic
exposure disrupts angiogenesis through
dysregulation of VEGF signalling. Protein
level of core regulator of angiogenesis,
VEGFA is reduced by arsenic exposure.
Using immunostaining, confocal microscopy
and quantitative 3D image analysis we
have been able to prove this hypothesis
correct.
Introduction
Zebrafish are vertebrates, easy to maintain
and manipulate, small size, able to be kept
together in large numbers and adaptive to
different environment, easy to breed, high
spawning rate - both in number and
frequency, embryos are transparent and
develop quickly; eggs are externally
fertilization and embryos are transparent !
Angiogenesis is the physiological process
through which new blood vessels form from
pre-existing
vessels.
Intersegmental
Vessels are targeted for angiogenesis
studies as they have a very predictable
growth at different stages of embryonic
development and highly directional in
nature. Vascular endothelial growth factor
(VEGF) is a signal protein produced by
cells that stimulates vasculogenesis and
angiogenesis. VEGF-A is a type of VEGF;
stimulates endothelial cell mitosis and cell
migration and also helps in creation of
blood vessel lumen.
Arsenic contamination of groundwater is a
high-profile problem in different parts of the
world including western USA, China,
Bangladesh and India (ganges delta).
Arsenic is also a reproductive toxicant and
a teratogen, is readily transferred across
the placenta causing birth defects.
Theory
SHH expression in Notochord.
VEGF‐A expression in Somites.
VEGF‐A secreted into ECM; binds to Fibronectin.
Matrix Metalloproteases (MMPs) secreted from ECs (tip cells); ECM degraded and VEGF‐A freed
VEGF‐A binds to VEGFR‐2
VEGFR‐2 mediates the cellular signaling – Upregulates DLL4 (Notch P/W)
15 VEGF upregulates notch signaling. Notch
signaling upregulates MMPs, releasing
more VEGF.
Experimental
Embryos used in the experimentation were
flk-1 - EGFP transgenic fish embryos of age
18-24 hours post fertilization (hpf) - control
and Arsenic (Sodium Arsenite ) treated at
100 ng/ml and 400 ng/ml concentration.
First, we exposed the embryos to primary
antibodies against GFP (Alexa Fluor-488anti- GFP), VEGF 165A (Anti- VEGF 165A)
and a fluorochrome Rhodamine Lens
Culinaris-agglutinin,
a
rhodamine
conjugated lectin. Then a secondary
antibody against the anti- VEGFA was
introduced to the embryos.
VEGFR2
LCA
Effect of Arsenic Exposure on
VEGF-A Expression in Somites Around the ISVs
VEGFA
165
For 3D Image Acquisition of the embryos
using a confocal microscope we set image
acquisition parameters based on brightest
samples in each channel. We set the laser
power, gain and offset so that signal was
within the dynamic range of the detector
(pmt-photo multiplier tube)- 256 intensity
levels. We used identical acquisition
parameters for all samples. The excitation
used and emission range collected - Green
channel: ex 488nm -> em 500-560nm, Red
channel: ex 543 -> em 555-700nm and Far
red channel: ex 633 -> em 650-750nm.
We then measured the average VEGF
intensity levels around the ISVs using the
TrackEM2 plugin suite in FIJI-ImageJ. The
TrackEM2 is used for 3D image processing.
It allows segmentation and analysis of
image under segmented region.
Conclusion
VEGF-A expression was greatest around
ISVs at 23 hours. At most time points
examined, addition of arsenic decreased
VEGF-A expression in a dose dependent
manner.
16 PERFORMANCE ANALYSIS OF HMPID (HIGH MOMENTUM PARTICLE
IDENTIFIER DETECTOR) OF ALICE (A LARGE ION COLLIDER
EXPERIMENT)
Shivani Bansal
Fourth year B. Tech. student, Department of Computer Science and Engineering
European Organisation of Nuclear Research (CERN), Geneva
May 12- July11, 2013
Abstract
ALICE(A Large Ion Collider Experiment) is a
heavy ion detector on the Large Hadron
Collider(LHC)ring. It is used to study the
physics of strongly interacting matter at
extreme energy densities, where a phase
called quark-gluon plasma forms. ALICE has
many detectors to identify the particles
generated during the collision of ions. HMPID
is one of such detectors which is used for the
identification of particles with momentum in
the range 3-5 Gev/c. Here we have done the
performance analysis of HMPID to measure
various parameters (Photon cluster charge
distribution, number of photons, tracks of
particles) using the data of LHC 2010, 2011,
2012.Plots have been made to compare the
parameters of the detector for LHC 2010,
2011, 2012.
The Cherenkov photons refracts out of the
liquid radiator and reach the CsI-coated pad
cathode, located at a suitable distance (the
`proximity gap`) that allows the contribution
of the geometrical aberration to the
Cherenkov angle resolution to be reduced.
The electrons released by ionizing particles
in the proximity gap, filled with CH4, are
prevented from entering the MWPC sensitive
volume by a positive polarization of the
`collection` electrode close to the radiator.
Each of the seven RICH module consists of
a six independent photo detectors and six
high voltage sectors. A Cherenkov ring is
formed in photo detector of the RICH
modules (an event is shown in Fig. 1).
Introduction
The ALICE HMPID is based on proximity
focusing Ring Imaging Cherenkov (RICH)
counters and consists of seven modules
mounted in an independent support cradle,
which will be fixed to the space frame.
Cherenkov photons, emitted when a fast
charged particle traverses the 15 mm thick
layer of liquid C6F14 (perfluorohexane), are
detected by a photon counter, which exploits
the novel technology of a thin layer of CsI
deposited onto the pad cathode of a multiwire proportional chamber (MWPC). The
HMPID detector, with its surface of about
12 m2, represents the largest scale
application of this technique.
Fig 1. An Event showing the formation
Cherenkov ring.
Analysis
The analysis have been made using a
software called ROOT which is most widely
used in high energy physics(HEP).The raw
data from the experiments have been taken
from the repository and processed using
WLHC grid to form .root files. The processed
data of LHC 2010, 2011, 2012 have been
taken as input to the different programs
written in ROOT to generate plots to make
17
the performance analysis of the seven RICH
modules of the detector. Plots have been
made taking into consideration the various
conditions existing in the detector while the
experiments had been performed like the
failure of some of the vessels of the radiator
of particular RICH modules.
The plots that have been studied are:
• Photon Cluster Charge Distribution
per HV sector(as shown in Fig. 2)
• Gain (A0) per HV sector(as shown in
Fig. 3)
• Number of Photons vs sin2 (qckov) per
photocatode. (as shown in Fig. 4)
• Number of photons has been
normalized for gain.
• Number of Pads vs sin2(qckov) per
photocatode.
Track selection for the study that have been
made are primary tracks selected using
standard cuts.For the number of photons
study full accepted rings have been used,
applying a cut on the corresponding track
position.
Fig.4 Number of Photons vs sin2(qckov) per
photocatode for RICH 3,LHC 10b
Comparison has been made as to why the
number of photons has been varying in the
given LHC period. Plots giving an overall
view with the data for all the LHC periods
gathered together has been generated
(shown in Fig. 3). This makes the study
easier. A comparison between the theoretical
results and practicals results has been done
and reasons for deviation between the two
has been given. During the analysis of how to
increase the mean number of photons it has
been concluded that increasing the cut on
momentum of particles from 3Gev to 4Gev
has a better impact than making a thinner cut
on the full accepted ring region. We try to
increase the mean number of photons
because while the theoretical value is 15, we
get around 11-12.
Fig.2 Photon cluster charge distribution for RICH
3,LHC 10b
Fig.3 Gain over the LHC periods for RICH 0.
Fig 4. Mean number of photons for p>4Gev
18 RESISTIVE SWITCHING OF TRANSPARENT COMPLEX
OXIDE RERAM FILMS
Soumya Sarkar
Fourth year B. Tech. student, Department of Electronics & Communication Engineering
NUSNNI, National University of Singapore, Singapore
May 15 – July 10, 2013
Abstract
Recently there has been a lot of research in
the field of finding alternatives of
contemporary flash memory. One such
alternative is ReRAM which functions due to
the resistive switching of metal oxides
between high and low resistance states on
application of electric field. The main idea
behind this project had been fabrication of
transparent ReRAM films and investigate
their V-I and R-V characteristics to determine
the type of switching. Furthermore the optical
properties of the device were also
experimented. The fabrication of the device
was done using the revolutionary PLD
technique and the measurements performed
using a PPMS.
.
Introduction
In the past decade or so, advancement in the
field of information technology has been
magnanimous. Consequentially the need for
reliable high capacity and high speed nonvolatile memory devices has accelerated.
Modern semiconductor nonvolatile memory
have been successfully scaled to achieve
high capacity memories but it is feared that in
the future years this physical scaling will
reach a boundary limit. An alternative is
ReRAM or Resistive Random Access
Memory. ReRAM technology is based on the
resistive switching behavior of complex metal
oxides and they have shown
promising characteristics for next generation
non-volatile memory applications.
Theory / Model
In this project, the metal insulator transition
(MIT) properties of complex metal oxides on
application of electric field and their resistive
switching behavior has been investigated
which can be utilised as a potential for device
applications. The current voltage and the
resistance voltage characteristics have been
analysed to determine its resistive switching
behaviour.
Previously a number of experiments have
been carried out in this exciting field of MIT,
where the transition has been electrically
induced. The innovation made in this project
is the use of a transparent top electrode
which shall enable us to study the optical
properties of the device by shining a beam of
light on it and observe the change in the
reflected light in response to the switching of
the complex metal oxide from HRS to LRS.
Experimental
The device used in this project is an
ITO/LAO/NSTO heterostructure fabricated
using Pulsed Laser Deposition.
In this method a high power pulsed laser
beam inside a vacuum chamber is made to
strike a target of the material to be deposited.
19 The V-I and V-R characteristics show that the
nature of the ReRAM switching is unipolar.
Fig: The ITO/LAO/NSTO sample
The material or target vaporises in the form
of a plasma plume and it deposits as a thin
film on a substrate facing the target generally
heated to an ambient temperature to grow a
crystalline film. The sample was then
investigated for its current voltage and
resistance voltage characteristics. The
sample was attached to a sample holder
using a double sided tape and the two
terminal connections were done using a wire
bonder machine with ITO as the top
electrode.
The characteristics of the device were tested
using the Physical Properties Measurement
System (PPMS) with the help of LabView
program and the results were plotted using
Origin 8.
Conclusion
The main objective of this project had been to
examine the possibility of resistive switching
in complex metal oxide thin films with a
transparent electrode, so that in future we
can move towards research in the field of
transparent devices with a more mature and
reasonable approach. I am indebted to
NUSNNI and NUS, Singapore for providing
me with the support and platform to perform
this project.
Fig: Current-Voltage Characteristics
20 DESIGN AND DEVELOPMENT OF PRINTED CIRCUIT BOARDS FOR
DIFFERENT CONTROLLERS OF A POWERED ORTHOSIS
Souransu Nandi
Fourth year B. Tech. student, Department of Electrical Engineering
Department of Mechanical Science and Engineering
University of Illinois, Urbana - Champaign, USA
May 27 – July 31, 2013
Abstract
The Human Dynamics and Controls Lab at
the University of Illinois has developed a
portable powered ankle foot orthosis
(PPAFO) to help people walk with gait
difficulties and help improve their walking
capabilities.
My
contribution
to
its
development was to design modular printed
circuit boards that could house all the control
circuitry required to operate the PPAFO
without affecting the gait pattern of the
patient.
the assistive torques at the appropriate times
and transmit all the data wirelessly to a
computer terminal for further analysis.
Introduction
Walking is one of the most essential activities
in the life of any healthy individual. In the
United States alone, there is a considerable
population of about 4.7 million people who
suffer from neuromuscular impairments in the
lower limbs due to polio, multiple sclerosis,
cerebral palsy and spinal cord injuries. [1]
An ankle foot orthosis (AFO) is a device
which could aid this growing population in
walking and regularizing anomalous gait
(walking pattern).
The PPAFO
The Portable Powered Ankle Foot Orthosis
(PPAFO) (Fig. 1) is a pneumatically powered
device which has been developed to provide
assistive dorsiflexion (toes up) and
plantarflexion (toes down) torques to an
ankle joint. [2]
Signals from sensors on the PPAFO helps
detect the different stages of gait. A
microcontroller based electronic circuit is
used to interpret these signals and provide
Fig.1. PPAFO
My Work
My work involved the study and improvement
of the electrical circuit, design of 3 printed
circuit boards (PCBs) to implement the
control & data transmission circuitry,
accommodate hardware changes and to
ensure compactness of the design to provide
least resistance to the natural movement of
the ankle joint.
Board 1
The existing control circuitry of the PPAFO
based on the microcontroller MSP430G2553,
had been improvised from breadboards and
training kits. (Fig. 2)
This assembly was bulky, prone to
mechanical impacts and had to be carried by
the subject on person while it was in
operation. In addition presence of a
21 microcontroller board was unnecessary
during the AFO operation.
To address these issues, a customized PCB
was designed to incorporate the entire
control circuitry efficiently. EAGLE CAD was
used to develop the schematic and the board
layout.
However, algorithms such as cross
correlation, nearest neighbour and particle
oscillator are also to be used in the future
which require more computational power and
memory than the present microcontroller can
provide.
Hence, microcontroller TMS320F28335 was
chosen for future implementation of control
circuitry. TMS320F28335 boasts of a flash
memory and RAM of 512kB and 68kB
respectively.
The TMS320F28335 control card (100 pin)
can be docked on an experimenter kit for
programming and signal processing. But the
experimenter kit is too big to be mounted on
the PPAFO without affecting gait pattern.
Thus EAGLE CAD was again used to draw
the schematic design and the board layout
for a new PCB housing the more powerful
microcontroller.
Fig.2. Original Control Circuitry
This PCB_1 provided a more compact,
reliable, ergonomic and a modular version of
the electronics.
The microcontroller could be programmed
separately on a different launch pad and
inserted in this board for the AFO operation.
Board 2
The PPAFO initially used a potentiometer
based angle sensor at the ankle to record
angular position during movement. However,
this sensor was heavy and unwieldy for its
position
and
hindered
natural
gait
movements. Hence, it was replaced by a Hall
Effect angle sensor.
To adapt to the new hardware, the control
circuitry was changed and a new board was
designed on the same software platform
based on the same microcontroller to
facilitate the change made.
This board (PCB_2) was made smaller in
size and more compact than the previous
one occupying a lesser volume of space
when attached on the PPAFO.
Board 3
An algorithm called the fractional time
algorithm is being used presently for gait
stage estimation. The MSP430G2553
microcontroller has a flash memory of 16kB
and RAM of 500 bytes which is sufficient for
executing the algorithm mentioned above.
Conclusion
The PPAFO is a device capable of improving
the standard of living of a large population
today, for whom walking is an arduous task
every time.
Each board that has been designed has been
a progress on the electronic side of the
PPAFO. The PCBs have separated the
programming unit and the execution unit
reducing unnecessary components on the
board.
Fig.3. Size comparison of the PCBs
They have catered to the hardware changes
and made the board as much more compact
as possible.
References
[1] Dollar and Herr, IEEE Transactions
Robotics, 24(1): 144-58, 2008
[2] KA Shorter, ET Hsiao Wecksler, GF
Kogler, E Loth, WK Durfee; JRRD, vol-48,
pp. 459-472, Nov 4 2011
22 MODELLING OF THE ELECTRICAL EQUIVALENT OF
RESISTIVE PLATE CHAMBERS
SUDIPTO MAJUMDER
Department of Physics
CMS Collaboration, CERN, Geneva, Switzerland
May 10 – July 13, 2013
Abstract
A study of the electrical equivalent of the
double-gap resistive plate chambers has been
presented in this paper. A systematic approach
from the modelling of a single gap to a double
gap RPC is performed. The equivalent circuits
are modelled with the help of “Circuit Maker”
software. The different components of the
double gap RPC has been modelled into
equivalent electrical elements that are
analogous in property. Finally, a compact
electrical circuit for the double gap RPC has
been arrived at. The modelling has been at par
with the physical working of the RPC gas gaps
for the detection of muon particles in the CMS
detector at CERN, Geneva.
Theory
An RPC is a particle detector introduced in
1981, utilising a constant and uniform electric
field produced by two parallel electrode plates,
at least one of which is made of a material with
high bulk resistivity. A gas mixture with a high
absorption coefficient for ultraviolet light is
flown through the gap between the electrodes.
When the gas is ionised by a charged particle
crossing the chamber, free charge carriers that
are deposited in the gasgap trigger avalanches
of electrons in the externally applied electric
field and originate a discharge.
Due to the high resistivity of the electrodes, the
electric field is suddenly dropped down in a
limited area around the point where the
discharge occurred. Thus the discharge is
prevented from propagating through the whole
gas volume. The propagation of the growing
number of electrons induces a current on
external strip electrodes.
When muons pass through a chamber
electrons are knocked out of the gas atoms.
These electrons in turn hit outer atoms causing
avalanche of electrons. Electrodes are
transparent to the signal (electrons), which are
instead picked up by external metallic strips
after small but precise time delay. The pattern
of hit strips gives a quick measure of the muon
momentum, which is then used by the trigger
to make immediate decisions about whether
the data are worth keeping.
Fig. A muon passing through the gas gaps,
consequent avalanche of electrons and
induction of charges on the readout strips by
capacitive coupling
Experimental Modelling
The RPC gas gap consists of mainly:
•Two Planer electrodes made up of Graphite.
•Two Bakelite plates are separated using
polycarbonate buttons shaped spacer
•Fill Gas mixture
•The pick-up panel composed of copper strips
soldered to wires which connect to electronics.
We relate each of the components with an
electrical equivalent:
1. The Bakelite plates can be represented as
two ohmic resistances one on both sides of the
circuit.
2. The spacers are represented by an ohmic
resistance.
3. The RPC gas gap ionisation volume is
represented by a Zener diode.
23 The Zener diode is incorporated in the circuit
because, the drift of electrons in the gas gap of
RPC happens due to avalanche mechanism
which is initiated by the acceleration of
electrons due to the high electric field in the
gas gap which is similar to the working of
Zener Diode.
This
figure
represents
the
equivalent electrical
circuit for a single
gas gap RPC.
In case of a double gap RPC, as in the
adjacent diagram, we have two similar sets of
single gap RPC, one on top of the other. In this
case, the read out strips are placed in between
the two single gas
gaps.
Negative
high voltage is
given
to
the
outermost portion
of the graphite
coating
of
the
system. The inner
portion
of
the
graphite coatings
of the two gas gaps are grounded along with
the read out copper strips. The signals from
the readout strips are then amplified and
discriminated by the front-end electronics for
the appropriate signal at the observer’s end.
Now for preparing the electrical equivalent
circuit of this Double Gap RPC we have to
consider three separate simple circuits for the
top narrow, top wide and the bottom.
• Each read out strip can be considered
as a transmission line with inductances
in series and capacitances in parallel to
the ground. However, for simplicity we
are considering only the inductances in
series.
• Also in the previous case for the single
gap RPC we did not consider the read
out strips in the equivalent circuit. The
readout of RPCs occurs via capacitive
coupling to external strip or pad
electrodes, which are fully independent
of the sensitive element (the gas gap).
o Cc= Capacitive coupling
o Cs= Stray capacitances between strips
o f.e.b= Front end boards
In this equivalent only two strips are
considered. We find that for Top narrow 32
strips and that for Top Wide 64 strips can be
realised. For the bottom gap all 96 strips are
realised. Hence, the bottom is capacitavely
coupled with all the strips. Also, Top Narrow
and Wide are coupled with 32 and 64 strips
respectively. Each strip carries the charge
when hit and the F.E.Bs with the amplifiers
produces the required signal. To represent the
inducing charges we used switches instead for
a closed circuit.
In this circuit all the grounds are connected
together. The f.e.b’s are the standard pcb
available in the CMS collaboration for the RPC
installations.
Conclusion
The equivalent circuit for the standard double
gap RPC has been modelled in this paper.
The circuit elements are assumed to be ideal
in their behaviour and hence there is a scope
for the practical realisation of the electrical
equivalent model of the RPC. The different
magnitudes of the elements are taken as to be
standard assumptions for the purpose of the
study. Actual realisations with practical values
extend into future scope of studies of the
Resistive Plate Chambers.
References
1. Fabrication and characterisation of
RPC , Asmita Redji, Scientific Officer,
INO
2. “Design and Characterisation Studies
of RPC”- Satyanarayana Bheesette, IIT
Bombay
3. The ATLAS Collaboration, ATLAS
Muon Spectrometer Technical Design
Report, CERN/LHCC
4. http://cms.web.cern.ch
5. Detector Physics of Resistive Plate
Chambers Christian Lippmann (CERN,
Geneva), Werner Riegler ,(CERN,
Geneva)
24 A MULTI-AGENT TEST BED FOR MICROGRID CONTROL
Vivek Kumar Singh
Department of Electrical & Computer Science, Michigan State University, USA
July 09 –August 8, 2013
Abstract
The project involves the construction of
multi agent system test bed for microgrid
control. It has been developed in Eclipse with
Jigloo GUI builder. In the designed test bed,
different computers working as agents are
communicating to each other to achieve the
global goal. There is no centralised
computer, each computer contributing
significantly to achieve the global goal. In this
project, we have worked on computers
having Ubuntu applications where time is
synchronised by connecting to internet using
NTP server. NTP is a TCP/IP protocol for
synchronising time over a network. Different
computers send their views in form of power,
voltage and frequency. It deliberately
explains the RTDS application and RSCAD
software suite.
Introduction
The project demonstrates the application of
eclipse in designing Multi Agent System.
Eclipse is basically a java based open source
platform that provides software developer to
create
a
customized
development
environment defined as IDE which stands for
Integrated Device Electronics which is a
standard Electronic Interface used between
computer data paths or buses.
The project involves the construction of a
flexible programmable Multi Agent System
test bed for laboratory use. The test bed
consists of 4 to 5 agents, each agent
comprising a hardware
controller with an
embedded
processor,
memory
and
communication channel. These agents will be
able to communicate with each other as well
as with Real-Time Digital Simulator (RTDS)
on which the power network of a microgrid
can be simulated. The whole project
emphasizes on decentralised Multi agent
System where no single agent unilaterally
commands other to achieve the main goal.
All agents have same significant role, they
are at same hierarchical level and obey
specific rules to communicate so that all
autonomous agents can coordinate to
manage the micro grid.
Fig 1.1 Agents Communication tree
Consider a system connected as shown in
fig.1.1 It is a simple but typical structure that
circulates into a complete ring structure. It is
easy to find that a communication algorithm
applied to this structure can be extended to a
more complicated structure which may have
multiple rings or radial lines In the project,
communication is done in one direction that
is unidirectional not bi-directional. Agent 2 as
shown in fig.1.1 has two paths of
communication. At particular instant of time,
it sends message either to 5 or 3 but it
cannot send message to both agents
simultaneously.
Designed Model
We have designed a simple model for the
proposed project in java based application
softwareEclipse
Fig 1.2
Designed Model
25 In the proposed design model, we have taken
maximum 5 computers working as agents
communicating unidirectional to achieve
the global goal. There is no centralized
computer, each computer contributing
significantly to achieve the global goal. When
PC1 working as agent is processing
information at a given point of time, it is
termed as current agent. If agent PC1
transmits information to agent PC2, then PC1
is called PC2’s parent agent and PC 2 is
called PC1’s child agent. The Fig1.2
deliberately explains the concept of parent
and child agent.
Implementation & Simulation
We are working on the Ubuntu
installed
computers where time is synchronized by
connecting to internet using NTP server. NTP
is a TCP/IP protocol for synchronizing time
over a network. Basically a client requests
the current time from a server, and uses it to
set its own clock. All agents are programmed
in eclipse in
such a way that processing
starts together irrespective of time delay.
Every agents have its own views. It is
basically an agent’s knowledge of system
information. It consists of maximum real and
reactive power generation capacity Pg, Qg,
dispatchable
real and reactive power
generation capacity Pdg,Qdg ,vital real and
reactive load demand Pv, Qv and non-vital
real and reactive load demand Pnv, Qnv in
the designed model. In the mentioned
project, we have defined a class called script
.java where we have defined different
parameters of power, frequency, voltage and
time (ms) with values to get
different
readings .The input script file is written in Ms
Excel where frequency is increasing to
1decimal unit for every 5 sec.
Clock Design in Eclipse
During project, we have to design a clock
with label in order to initiate the
communication
of
different
computer
simultaneously and to calculate the lagging
time between different agents. We defined a
class called setting. When we type some
texts in the text field and press the button,
text is written into a file. The file is a simple
text file which stores the information of path
of workspace where data have been saved
earlier. When I start the program again, it
should read automatically the text in the file
and print it in the same text field. We have
checked box which determines whether the
file is checked or not.
Conclusion
The proposed project is a modern approach
to comprehensive control strategy of micro
grid. The proposed project utilizes the
concept of power control strategy to different
computers working as agents in order to
design multi agent system test bed. It
deliberately explains the RTDS application
and RSCAD software suite. It demonstrates
the views of different agents working together
to achieve the global goal using different
parameters and mathematical values. It
also demonstrate the application of agent
tool III in multi agent system engineering
which can play a significant role in future
while designing multi agent system test bed.
Acknowledgement
I would like to give my sincere thanks to
research committee of NIT Durgapur for
providing financial assistance to carry out the
summer project in foreign university. I would
like to express my great appreciation to Prof.
Joydeep Mitra for his patient support,
valuable and continuous guidance throughout
the project. I would like to thank Mohammed
Ben-Idris and Niannian Cai for keeping me
motivated all the time during the project and
making me feel comfortable with the new
environment. My grateful thanks are also
extended to Mrs. Pauline Vandyke for
assisting me in getting identity card and
activating my account and Mrs. Jennifer
Woods for providing me the keys and access
to ERISE summer lab.
26 SEMANTIC WEB-BASED E-COUNSELING SYSTEM
Anish Singhania
Fourth year B. Tech. student, Department of Information Technology
pp. 70-74, Proceedings of International Multi-Conference on Software, Electronics,
Communication and Mechanical Engineering (IMSECME'12),
Dec. 29 -30, 2012, Kuala Lumpur (Malaysia)
Abstract
Presently on Internet, it is difficult to find a
resource which serves as one-stop
destination for students regarding their
career-related queries. Students who use
Internet to search for help end up with large
amount of information, mostly irrelevant. This
happens because of current syntax-based
web search which just matches words of the
query and returns all string-matched results.
Thus, this research work proposes a
Semantic web-based e-counseling system. It
captures the query from the student in
Natural Language, understands the logic of
the query and returns a reply just as a human
counselor would, which helps the student to
find a proper career option with less efforts
and time. The Natural Language Query is
parsed by a NLP Parser to form a data
structure which is compared to the Ontology,
a hierarchical set of concepts and relations of
a domain, and only relevant options are
presented to the student.
Introduction and System Overview
In general, in an e-counseling system, a
student is required to enter his choice of
subject and field of interest in a form-based
enquiry and a huge amount of data, both
relevant and irrelevant, is returned to the
student as a result. These results are not
entirely according to the student’s need as
the form prevents the student from
completely expressing itself. The vast
expanse of data available on the web further
adds to the woe.
The proposed system gives a real-life
counselor-like
reasoning
and
logical
capability to the searching mechanism. The
student now can enter a query according to
its own needs and get a result that it wants.
This allows the student to interact more with
the system and hence a lot more queries are
asked and results returned, in contrast to the
form-based system wherein the extent of the
queries is limited. This is the concept that is
underlying the Semantic Web Technology.
The proposed idea uses forms a hierarchy of
the available data, dividing them into classes
and relating them through properties
(relations) so that they can be semantically
searched through Ontology. Now, the student
queries to the system and the system forms a
semantic hierarchy of the query after parsing
the query and compares it with the ontology
to return a result. The system helps the
student by reasoning the question so that all
the relevant results are returned. For
example: If a student queries for ‘Computer
Science and Technology’, all results elated to
‘Computer’ and ‘Computer Science’ will also
be returned, helping the student by returning
logical results.
Implemented System Architecture
A. Interface
A web-based medium between the user and
the underlying semantic search system that
accepts a query in Natural Language to be
processed .The query is processed by the
underlying system and finally the result is
displayed. Therefore, the interface helps the
user interact with the system.
B. NLP parser
Parser is a Java-based tool used to parse
natural language query and to analyse the
grammatical structure of the sentence. It
groups together words to form phrases and
resolves the different dependencies into
various parts of speech. It parses the input in
various output formats and saves the
resultant output in a .txt or .xml file.
27 C. XML Parser
The XML Parser, SAX (Simple API for XML)
is an event based sequential access parser
API used to parse XML files. A parser that
implements SAX functions as a stream
parser, with an event-driven API. The user
defines a number of call back methods that
will be called when events occur during
parsing. The SAX events include (among
others) XML Text nodes, XML Element Starts
and Ends, XML Processing Instructions, XML
Comments. The minimum memory required
for a SAX parser is proportional to maximum
depth of XML file and the maximum data
involved in a single XML event.
D. J-Tree
J-Tree is a class in the javax.swing package.
It is a Swing component that displays a set of
hierarchical data as a tree outline. Like most
Swing components, it has a model, is highly
configurable through the use of renderers,
and fires events that can be handled. Each
row displayed by the tree contains exactly
one data item, which is called a node. Every
tree has a root node from which all nodes
descend. Branch nodes can have any
number of children. Like any non-trivial Swing
component, the tree gets its data by querying
its data model, where a specific node can be
identified by a TreePath, an object that
encapsulates a node and all of its ancestors.
E. Ontology
Ontology are logical systems that constrain
the meaning of data. It provides logical
linking of data along with its annotations.
OWL makes it possible to describe concepts
but it also provides new facilities. It has a
richer set of operators-e.g. intersection, union
and negation. It is based on a different logical
model which makes it possible for concepts
to be defined as well as described. Thus,
Ontologies are considered as one of the
pillars of the Semantic Web.
are mapped with concepts (classes) and
verbs with properties (relations) and then the
result of the search is displayed with the help
of the interface.
The
System
can
schematically through
be
represented
Fig.1: System Architecture
Conclusion
In this work, we have introduced an ecounseling system for the benefit of the
students so that the machine can do the work
in favour of them therefore with reduced
efforts in less time. Thorough case studies
have been done in this regard and the results
have been quite satisfactory up to this stage.
In the future, this work can be expanded to
include larger domains of education and form
a singular aide for all students regarding any
of their career related queries.
F. Mapping code
The Mapping code maps the tree, obtained
from the parser output, with the Ontology. It
matches the nodes of the output tree with the
tags in the XML file of the OWL Ontology.
The XML file is parsed using the SAX parser.
The complete tree is traversed and the nouns
28 MODELLING OF MULTIAGENT BASED RAILWAY SYSTEM
USING BDI LOGIC
Ankit Bhardwaj
M. Tech Second year student, Department of Information Technology
International Conference on future trends in computing and communication-FTCC 2013
Bangkok, Thailand
July 13-July 14, 2013
Abstract
Multi-Agent based modeling & simulation is
an evolving paradigm for solving real life
problems for solving real life problems for the
last one decade. In this paper, we model the
manually controlled Indian Railway to a multi
agent based automated system which is
robust in nature and provide a fully
automated collision avoidance guarantee.
We consider individual entity such as station,
junction and train as an agent and the whole
railway network is framed as a graph. To
sharpen the solutions of existing system´s
problems such as collisions and delays, BDI
agent with first order predicate logic is
incorporated
in
this
paper.
The
communication and coordination between
respective agents (with help of their BDI and
rule base running as backbone) can now be
a substitution in place of manual decisions.
Thus the idea can replace the hectic job of
railway control room personals in more
sophisticated & methodical way.
Introduction
Railway system is the biggest public
transportation in the world which is used to
provide better transportation service to the
public than private one. There are lots of
advantages of using the public transport such
as lesser fuel consumption, convenience,
lesser fare, lesser pollution and many more.
But in parallel with these advantages the
existing
railway
system
has
some
disadvantages also like Collisions and delays
and unfortunately they are more dangerous
and lossy than private transport.
Railway is a distributed system which can be
efficiently modelled by the intelligent agents.
A Software Agent [1] is essentially a special
software component that has autonomy to
provide an inter-operable interface to an
arbitrary system. A Multiagent system (MAS)
[2] is a group of agents, which interact with
each other and negotiate in a decision to
achieve a common goal. MAS can be
empowered with the help of BDI theory. BDI
is a philosophical and mental model for
multiagent based problems. Railway system
is a Socio-Technical system which can be
modeled by BDI agent [7] using three words
Belief, Desire and Intension. During his
lifetime an agent go though in following
working loop depicted in Fig:1 :
Fig. 1: Working principle of BDI
Now apart from the BDI theory we are going
to concatenate first order predicate logic in
this paper which empowers the railway model
many
times.
The
combination
of
mathematical logic and BDI theory gives
stronger solution for railway system problems
because the logic gives precise meaning to
mathematical statements.
System Model
• System Architecture
We define railway system by following tuples
set:Rsys = < G, A>
Where, G is a Graph representation of
railway tracks and stations.
A is a set of agents deployed on the
graph.(Figure: 2)
Now the graph G can be defined as
G = < V, E >
Where, V is the set of vertices and E is the
set of directed edges. Again,
V=SUJ
29 S = { Si | i=1,2….n}
Si ϵ S represents a station node with an
unique id i
And J = { Ji | i=1,2….m}
Ji ϵ J represents a junction node with an
unique id i
J = { x | x ϵ V, and Capacity(x)=1 and
Waiting_on(x)=0 }
In the graph of this system model we are
considering the directed edges so trains can
move in these directions only .
Eijk = Vi → Vj
And E = { Eijk | Vj = AdjG(Vi) }
Here AdjG(Vi) is a adjacency function which
determines the adjacent nodes of Vi . As
there may be more than one edge between
Vi to Vj , to uniquely define each edge
between Vi to Vj we define Eij as Eijk. Where
{ k = 1, 2….e } and e is the total number of
edges directed from Vi to Vj .
Now the another parameter of the system
model is A (agent),
A = SA U JA U TA
Where
SA = { SAi | i=1,2….n}
SAi ϵ SA represents a Station Agent with an
unique id i which is static in nature.
JA = { JAi | i=1,2….m}
JAi ϵ JA represents a Junction Agent with an
unique id i which is static in nature. In our
system model a train agent can be defined by
the following attributes,
TAi : <ID,R,ST,WT,MPS>
Where, ID = Unique id of the train agent TAi.
R[i][j] is List of stations that TAi must follow
as its Route and { j = 1, 2…. n }, while n is the
total number of stations in the route of TAi.
ST[i][j] is Schedule time of TAi in the jth
station (R[i][j]),WT[i][j] is Waiting time of TAi
in the jth station (R[i][j]), MPS is Maximum
permissible speed of TAi.
Similarly SAj: <ID,Capacity,LT,AS,Edge>
And JAk : <ID,LT,AS,Edge,B>
Where, ID is Unique id of the respective
agent, Capacity is maximum number of trains
SAj can hold at a time, LT[p] is List of trains
those left SAj or JAk but still not reached to
the next stop, AS[p] is List of adjacent
stations of SAj or JAk, Edge[p] is List of
outgoing edges of SAi.
• BDI Architecture of System
To differentiate among tags of BDI, we give
the following well defined structure to
represent belief, desire and intension. The
predicates and functions which we use
frequently to define the BDI of a agent are
summarized in Table: I.
1) Belief Logic Tags: <B A Belief1>
Here < > is used to denote the tags. First
character of tag can have three possible
characters B, D and I which denote the tag
type. B is used for Belief tags. Second
character of the tag contains agent id. In
above belief tag, we put the agent id A, who
has the state of environment Belief1 as belief.
2) Desire Logic Tags: <D A Desire1>
Similarly, here D denotes the tag type that is
desire and A denotes the agent id. The
above tag denotes that agent A has desire
Desire1. Like <D TA1 CurrentSpeed(MPS)>
tag denotes that TA1 has a desire to gain the
MPS.
3) Intension Logic Tags:
<I A Intension1>
Intension is a desire with commitment to fulfill
it. So the difference between the Intension
and desire tag is tag type symbol only. Rest
parts of the tag remain same for an intension
tag of a agent like desire tag.
Conclusion
In this paper we propose a BDI logic based
modeling of railway system which gives a
strong foundation to solve the problems of
existing railway system and also gives an
autonomous shape to it. Our proposed model
promotes the utilization of predicate logics
with multi agent system to enhance the
quality of service of the system. In a concise
form we can state that this paper is directed
to develop a BDI agent based autonomous
railway system (with the rule base as a
backbone) which can overcome the fallacy of
manual intervention and human dependency.
The future prospect of this work will be
simulate the whole network with JADE (which
is a Java based agent oriented tool) by using
the real dataset collected from the Asansol
division of Eastern Railways, India which can
give the flavour of real time simulation.
30 EFFECT OF ANNEALING ON YELLOW ORANGE
PHOTOLUMINESCENCE EMISSION OF UNCAPPED Mn2+ DOPED ZnS
QUANTUM DOTS SYNTHESIZED BY SIMPLE CHEMICAL METHOD
Arup Kanti Kole
Ph D student, Nanoscience Laboratory, Department of Physics
7th International Conference on Materials for Advanced Technologies
Suntec, Singapore, June 30-July 05, 2013
Abstract
Amongst others doped ZnS nanomaterials,
Mn2+-doped ZnS quantum dots (QDs) have
promising applications in optoelectronic
devices. Annealing treatments are also very
common in semiconductor processing and
can be used to improve the crystal quality
and to confirm the stability of the crystal,
which is important for device fabrication.
However, in this work synthesis of uncapped
40.0 mol% Mn2+ doped ZnS QDs of average
sizes ~2.5nm in de-ionized (DI) water
medium at room temperature (RT) is
reported. The particle size is confirmed by
Transmission Electron Microscope (TEM)
and X-ray diffraction (XRD) studies.
Unannealed samples show dual PL emission
peak, one centred at 400 nm assigned due to
recombination between the sulphur vacancy
related donor and zinc vacancy related
acceptor levels, other at yellow-orange
region, centred at 600nm assigned due to
partially allowed 4T1-6A1 transition of Mn2+ in
ZnS. The XRD patterns show that the
transformation from cubic ZnS to wurtzite
ZnO phase has taken place at 6000C
temperature. There are various reports of
Mn2+ PL emission enhancement by
annealing, but in the present experiment, for
the first time, we have observed that the
intensity of Mn2+ related yellow-orange
emission peak decreases continuously with
the increase of the annealing temperature.
The reduction of yellow-orange PL emission
intensity might have taken place due to the
diffusing out of Mn2+ dopant from the ZnS
lattice during annealing.
Introduction
Out of various II-VI semiconductor QDs, ZnS
has attracted a lot of attention due to its wide
direct band gap (3.68eV at room
temperature), large exciton binding energy
(~40meV) and potential application in solar
cell, flat panel display, sensor, laser and
photocatalytic dye degradation etc. By doping
transition metal ion such as Ag2+, Co2+, Cu2+,
Mn2+ etc. in ZnS semiconductor QDs, the UVVis optical absorption and PL emission
properties can be tuned easily and makes it a
promising material for its application in
various
optoelectronic
devices
where
tenability is required. Another important
technique to obtain efficient and tuned PL
emission from semiconductor QDs is the
thermal
annealing.
Such
annealing
treatments are widely used in semiconductor
processing to improve the crystal quality and
to confirm the stability of the crystal, which is
important for device fabrication. In the
present work we have reported the effect of
thermal annealing at 100-6000C temperature
range on structural and PL emission
properties of uncapped ZnS and ZnS:Mn
QDs of average sizes~2-3nm synthesized by
simple chemical precipitation method at RT.
Experimental
ZnS QDs and Mn2+ (40 mol%) doped ZnS
QDs are synthesized at RT by simple
chemical co-precipitation method in DI water
medium. All the chemicals used are of AR
grade (Merck and SD fine chemicals,
Mumbai) and are used without further
purification. For the synthesis of ZnS QDs,
zinc nitrate is dissolved in DI water. After 1 h
of continuous stirring, sodium sulphide
solution in DI water is added drop-wise into
31 the zinc nitrate solution. After 1 h continuous
stirring of the reaction mixture, the precipitate
is then separated by centrifugation. For the
synthesis of Mn2+ doped ZnS QDs,
manganese acetate dissolved in DI water is
mixed with the zinc nitrate solution. After 1h
continuous stirring of the reaction mixture,
sodium sulphide solution is added drop-wise
and it is again stirred continuously for another
1h. Finally the precipitate is collected by
centrifugation and dried in RT for further
measurements. The samples are then heated
at the rate of 100C/min for 1 h and held for 2
h at four different temperatures of 100, 200,
400, and 6000C in a muffle furnace. Then the
samples are cooled at the rate of 100C/min
(furnace cooling). The samples are then
collected for further measurements.
The UV-Vis absorption spectra of the
annealed samples show a red shift with
increasing annealing temperature due to the
increase in particle size as a result of
annealing which is further confirmed from
TEM image analysis. XRD data analysis
show that upto 4000C annealing temperature,
the crystallinity of the samples increases as
the annealing temperature increases and at
6000C temperature, cubic ZnS has converted
to wurtzite ZnO.
We have studied the effect of annealing on
the PL emission spectra. For undoped ZnS,
only one PL emission peak at 400nm can be
observed where as for Mn2+ doped ZnS QDs,
in addition to this peak another yellow-orange
emission peak at 600nm can be observed.
The UV emission is assigned due to
recombination between the sulphur vacancy
related donor and zinc vacancy related
acceptor levels. When Mn2+ ions are doped in
ZnS, it occupies the sites of Zn2+ and the
mixing between the s–p electrons of the host
ZnS and the d electrons of Mn2+ occurs and
made the forbidden 4T1-6A1 transition partially
allowed and it results Mn2+ related yelloworange PL emission. The UV emission peak
present in both undoped and Mn2+ doped
ZnS samples at first increases with increase
in annealing temperature upto 2000C due to
the improved crystallinity as observed from
XRD analysis and it decreases at 4000C
temperature may be due to the removal of
the defect at this temperature. Further it
increases at 6000C and it corresponds to the
strong excitonic emission of ZnO as
observed earlier by other researchers for
ZnO QDs. There are various reports of Mn2+
PL emission enhancement by annealing, but
in the present experiment, for the first time,
we have observed that the intensity of Mn2+
related
yellow-orange
emission
peak
decreases continuously with the increase of
the annealing temperature. The reduction of
yellow-orange PL emission intensity might
have taken place due to the diffusing out of
Mn2+ dopants from the ZnS lattice during
annealing. Further increase in particle size
due to annealing beyond the ‘quantum
confinement’ regime leads to weak
interaction between the d electronic state of
Mn2+ and the s-p electronic state of host ZnS
leading to a decrease in yellow-orange PL
emission intensity.
Conclusion
Synthesis of ZnS and Mn2+ doped ZnS QDs
of sizes ~2-3nm at RT by using simple
chemical precipitation method without using
any capping agent is reported. The effect of
annealing on RT PL emission spectra of Mn2+
doped ZnS QDs have been studied in detail
and it shows continuous decrease in PL
emission intensity with increasing annealing
temperature. This decrease in PL emission
intensity has been attributed to the diffusing
out of Mn2+ dopant in ZnS during annealing.
The yellow-orange emission as observed
from Mn2+ doped ZnS QDs show that it can
be used in future optoelectronic devices
Acknowledgement
I am thankful to my thesis supervisor, Dr. P.
Kumbhakar, Professor, Dept. of Physics, NIT
Durgapur for providing me the opportunity for
this visit. I also acknowledge Department of
Science and Technology (DST), GOI, and
NIT Durgapur, India for providing the Air fare,
visa fee, registration fee etc.
References
[1] R.N.Bhargava, D.Gallagher, X.Hong, A.Nurmikko,
Phys. Rev. Lett. 72, 416 (1994).
[2] A.K.Kole, C.S.Tiwary, P.Kumbhakar, J. Appl. Phys.
113, 114308 (2013).
[3] D.Son, D.Jung, J.Kim, T.Moon, C.Kim, B.Park, Appl.
Phys. Lett. 90, 101910(2007).
32 A FAMILY OF FLEXIBLE OFFSET-TIME BASED WAVELENGTH
SCHEDULERS FOR OBS EDGE-NODES
Bikash Choudhury
M. Tech Second year student, Department of Information Technology
IEEE 3rd International Conference on Photonics - ICP 2012
Pulau Pinang, Malaysia, Oct 01-03, 2012
Abstract
A family of variable offset-time based
wavelength scheduling schemes for OBS
edge-nodes, is proposed which performs 420 times better than ordinary LAUC-VF
schedulers in terms of byte loss rate (ByLR).
The schedulers accept a minimum and a
maximum limit of offset-time along with the
length of the burst as input and then return
the appropriate wavelength and the exact
offset-time, to be used for the burst. The
basic principle is to align the burst either at
the beginning or at the end of an existing void
so that no new void is created after
scheduling the burst unless mandated by the
offset-time limits.
exact (within the given range) offset-time is
decided by the scheduler itself. In the existing
schemes, the scheduler is provided with the
rigid offset-time(t0) and burst-length(B) of the
new (to be scheduled) burst. The scheduler
has to search for the voids in each channel
that can hold the burst and then according to
a scheduling criterion, the appropriate
wavelength is selected. But, in our approach,
the scheduler is provided with the burstlength and a lower limit(tmin) and an upper
limit(tmax) of offset-times. The scheduler then
returns a wavelength (λ), at which the burst
should be scheduled and also an offset-time
(t0) within the given range. The basic
difference between our approach and
existing approaches is illustrated in Fig.2.
Introduction
Since its inception, optical burst switching
(OBS) technology has attracted the attention
of networking community throughout the
world and now it is being considered as a
very
promising
technology
towards
implementation of all-optical Internet in near
future. OBS combines the advantageous
features of optical circuit switching (OCS)
and optical packet switching (OPS)
techniques by elegantly separating control
plane functionalities from data plane.
Statistical multiplexing gain (SMG), slightly
lower than that offered by OPS, can be
derived without processing the packets
electronically. Data packets from a source to
a destination can be forwarded all-optically
without requiring optical/electrical/optical
(O/E/O) conversion at the intermediate
nodes. Moreover, in doing so, the SMG is
just marginally compromised.
we propose a scheduling scheme for edge
OBS nodes, where the offset-time is allowed
to be variable within a given range and the
Fig. 2: Existing and Proposed approach
The Proposed Scheme
The basic objective of our approach is to
minimize the number of voids by
concatenating the new burst with an existing
burst if possible (meeting the offset-time
constraints) so that no new void is created
after scheduling the new burst. This can be
done in various ways. One possible way is to
search the void of maximum length among
the contending wavelengths within the given
range of offset-time and then scheduling the
new burst either at the beginning or at the
end of the void. We term this scheme as
max-void variable offset-time scheduling. In
this scheme, we have two variations - the
33 new burst can be scheduled at the beginning
or at the end of the maximum void. We term
them as max-void-min-offset scheduler and
max-void-max-offset scheduler respectively.
Both the schemes give significant loss
reduction compared to that obtained from
existing schemes but the schemes are likely
to favour burst of smaller size compared to
burst of larger size, that may arrive in future.
General Framework:
We define a slot as a two tuple vector (t; s)
where t denotes the start-time of the slot and
s denotes the state (empty or occupied) of
the slot. Note that s can assume either 0 if
the slot is void (empty) or 1 if the slot is
occupied. Thus state of an wavelength w can
be represented as an ordered sequence of
slots. For convenience of computation, we
assume that the start-time of the first slot is
always zero and the state of the last slot
(actually the void at the end) is always zero.
Thus state of w can be represented as
w={(0,s1), (t2,s2),.., (th,0)} ----(1)
where th is termed as the horizon of the channel.
Now, we define the max-voids and min-voids
for the schemes as follows
vmax1 = maxi,j{vij,V vij ϵ V1 } ---(2)
vmax2 = maxi,j{vij,V vij ϵ V2, provided tmin≤tB≤tmax}
---(3)
vmin1 = mini,j{vij,V vij ϵ V1 } ---(4)
vmin2 = mini,j{vij,V vij ϵ V2, provided tmin≤tB≤tmax }
---(5)
An additional constraint, as mentioned above, on (4)
and (5) is that vij≥ B + Bmin
The Schemes
1) Max-Void based Schemes: First, we
outline the steps involved in the max-voidmin-offset scheduler as below
a) Search vmax1 within the link and return the
wavelength in which vmax1 occurs.
b) Return the start-time of vmax1 as the offsettime to be used for the new burst.
2) Min-Void based schemes: A criticism to
the above schemes is that as the new burst
is scheduled at the vmax1 or vmax2, the
algorithm will gradually reduce the size of
vmax1 or vmax2 and bursts of larger lengths will
never have a chance to be scheduled. So,
we study a diametrically opposite scheduling
scheme, named as min-void variable offsettime scheduling, as follows:
a)Find vmin1 and schedule the burst at the
wavelength to which vmin1 belongs. The value
of vmin1 should be at least equal to (B + Bmin).
b) Return offset-time, equal to the start-time
of the void vmin1.
At this point, we analyze the complexity of
the proposed schemes. Let, W be the
number of wavelengths available per
link then complexity of LAUC-VF is O(W) i.e.
it has to make W number of comparisons
before scheduling the burst. Our proposed
schemes have to search the min-void or
max-void over all wavelengths within the
limits tmin and tmax. If the average burst length
is B’, then number of voids in the link is
O(W(tmax - tmin)=B’) and hence the complexity
of the proposed scheme is O(W2(tmaxtmin)=B’).
Results and Discussions:
The results obtained for various schemes
from above studies are shown together in
Fig.2 for average burst-duration of 90 µs
considering the 2 hop topology as discussed.
above.
Fig2: ByLR for LAUC-VF, Max-Void, Min-Void and Mod-max
with average burst duration = 90_s and hops = 2
Conclusions and Future Scope
We propose two scheduling schemes that
place the burst within the void of maximum
size.
Max-void-min-offset-time
scheme
schedules the burst at the beginning of the
maximum void whereas max-void-max-offsettime scheme schedules the burst at the end
of the max-void. The ByLR performance of
max-void-min-offset-time scheme is found to
be better than the other scheme and
compared to LAUC-VF, it performs 4 to 20
times better, based on average burst-length
and applied load. Then a scheme is
proposed where the burst is scheduled at the
beginning of the minimum-void in the link.
34 CHAOTIC BLOCK ENCRYPTION WITH POSITION PERMUTATION
Debanjana Baksi
M. Tech 2011-13, Department of INFORMATION TECHNOLOGY
pp. 71-77, Proceedings of International Conference on Advances in Computing and
Communications Technologies, Pattaya, Thailand, January 19-20, 2013
Abstract
Chaotic encryption method is becoming
increasingly popular in real-time image
encryption/ decryption systems for its high
security, speed, computational overheads.
But it is not possible to generate pure random
numbers (true chaotic sequence) using finitestate machines such as digital computers
and dynamical degradation creeps in. This
paper reports that the security falls off in
chaotic encryption systems due to dynamical
degradation, from systems which use 32 bits
to generate chaos, to systems which use 8
bits for the same, and becomes insecure in
the case of systems which use 8 bits. The
paper also proposes a new algorithm based
on block based two layer permutations of
pixels, which works on systems using 8 bits
to generate chaos, enhancing its security
level. The resultant cipher has been found to
be resistant to known attacks. A comparison
in terms of some well defined metrics such as
correlation co-efficient, NPCR and UACI is
also done.
Keywords:
chaos,
image
encryption,
dynamical degradation, confusion and
diffusion, NPCR, UACI.
Introduction
Chaos based image encryption schemes
have been increasingly studied to meet the
demand for real-time secure image
transmission over the internet and wireless
networks. The development of chaos theory
began in the1960s (and established in
1970s) with efforts from many different
research areas (the pioneering research on
chaos may be retrospected to H. Poincaré’s
work in 1890s, when he found the complexity
of three-body celestial system), such as
mathematics , physics, biology, chemistry
etc. [Stewart, 1990]. Some researchers have
pointed out the tight relationship among
chaos,
communication
security
and
cryptography.
Many
fundamental
characteristics of chaos, such as the
ergodicity, mixing and exactness property
and the sensitivity to initial conditions can be
connected to the properties of “confusion”
and “diffusion” in cryptography. So it is
natural to use chaos to enrich the design of
new ciphers.
Experimental
In this work, a block based chaotic cipher
system has been proposed. This generates
chaos using 8 bit numbers and employs two
level pixel permutations to create confusion.
Final encrypted image is obtained using pixel
by pixel XOR operation between the plaintext
& chaotic sequence. This algorithm achieves
the desired properties of confusion and
diffusion and provides good resistance to
common attacks.
An experiment has been performed to obtain
the output of logistic map with 8 bit initial
condition. It is observed that the output does
not show sufficient sensitivity to initial
condition. Figures 2(a) to 2(c) show how the
difference in the plot of the output of logistic
map, with two slightly different 8 bit initial
conditions, shows periodicity. Thus chaotic
ciphers where 8 bit initial conditions are used
to generate chaos show less key sensitivity.
This is illustrated in figure 3(a)-(c).
35 Conclusion
Fig 3 (a) Lena image encrypted with key 11100001 (b)
Lena image decrypted with key 11100001 (same key)
(c) Lena image decrypted with key 11100000 (different
key)
A novel chaotic image encryption technique
is proposed. The new technique is capable of
reducing
dynamical
degradation.
The
encryption algorithm uses a 128 bit key (16
characters) to encrypt a 256 × 256 image
and it is highly sensitive to the initial
condition. Most importantly the scheme has
been designed in such a way that it works
successfully when chaos is generated using
8 bits. The map does not lose its chaotic
behaviour. Its computational complexity is
also very low and it has a large key space at
the same time. The proposed algorithm is
highly resistive against brute-force attacks
and histogram analysis establishes its
robustness against any statistical attack. The
obtained results show the superiority of the
proposed scheme.
A good encryption technique should be
robust against cryptanalytic, statistical and
brute-force attacks. The security analysis of
the proposed encryption scheme has been
performed extensively such as statistical
analysis, key sensitivity analysis, plain image
sensitivity analysis and key space analysis to
prove the security level of the algorithm.
After obtaining highly positive results in each
section it can be inferred that the proposed
algorithm is highly resistive against bruteforce attacks and histogram analysis
establishes its robustness against any
statistical attack.
36 QCA Multiplexer Based Design of Reversible ALU
Divyam Saran
M. Tech. 2011-13, Department of Computer Science & Engineering
pp. 168-173, 2012 IEEE International Conference on Circuits and Systems (ICCAS),
Kuala Lumpur, Malaysia, Oct 3-4, 2012
Abstract
The QCA (Quantum-dot Cellular Automata)
based reversible logic is gaining its
prominence in digital circuit for energy
efficient computations with high device
density. This work targets design of
reversible ALU in QCA framework. The
design is based on the 2:1 QCA multiplexer
introduced in this paper. The proposed ALU
satisfies the requirement of high device
density as well as the energy efficiency in
terms of computing power. Experimental
results establish the significant improvements
in the design level over that of conventional
design approaches.
Introduction
The QCA is based on encoding binary
information in the charge configuration of
quantum-dot cells. On the other hand,
reversible logic has attractive perspective of
constructing digital devices that can realize
computing unit with almost zero power
dissipation. The energy dissipation of a QCA
circuit can be significantly lower than kBTln2
due to its clocked information preserving
systems. This energy saving feature favours
the introduction of QCA technology with
reversible logic. Further, the multiplexer plays
an important role in digital designs. However,
the effectiveness of multiplexer based design
in QCA technology in terms of area
overhead, delay and complexity is yet to be
established. In this context, this work
explores the design of a reversible arithmetic
logic unit (RALU) in QCA technology. A cost
effective realization of 2:1 multiplexer is
introduced to outperform the efficiency of
existing designs. This effectively leads to the
synthesis of a reversible structure of 2:1
multiplexer. It is then utilized to synthesize
the desired RALU. The RALU design is
turned out as the most efficient on the basis
of complexity and speed of computation.
THE QCA MULTIPLEXER
The output of a 2: I multiplexer is,
Out = I1.Sel + I0.Sel
I0 and I1 are the two data inputs and Sel is
the select line. The majority gate
representation of this multiplexer is shown.
That is, 3 majority gates and 1 inverter are
needed to realize a 2:1 multiplexer.
F = M3(Ml(Sel, 10, 0), M2(Sel, 11, 0),1)
Fig. 1: Proposed QCA multiplexer layout and its design
Design
In [1]
In [2]
In [3]
In [4]
In [5]
Proposed
Complexity (#
Cells)
88
66
46
36
27
19
Area (µm2)
0.14
0.14
0.08
0.06
0.03
0.02
Latency
(clock cycle)
1
1
1
1
0.75
0.75
Table: Comparison of 2:1 multiplexers
REVERSIBLE MULTIPLEXER (RM)
Fig. 2 shows the reversible structure (RM)
realizing the 2:1 multiplexer. The input to
output mapping of RM structure is
P=AXORBC, Q=A'B+ AC, R=A'C+AB, where
A, B, C are inputs and P, Q, R are the
outputs. Its cell count is 224, covering an
area of 0.25 µm2. The measured input to
output delay is of 1.5 clock cycles.
Fig.2: Reversible Multiplexer (RM)
37
REVERSIBLE ALU (RALU)
A major application of the reversible
multiplexer is the design of reversible ALU
(RALU). The components of an RALU are the
reversible logic unit (RLU), a reversible
arithmetic unit (RAU) and an RM gate which
selects either output from the RLU or RAU.
Reversible logic unit (RLU)
A 4:1 multiplexer can act as an I-bit Logic
Unit if its data inputs are used as controls
and the select lines as two 1-bit inputs of the
ALU (Fig. 3). The design has 6 garbage
outputs. The QCA implementation of the
design requires only 3 RM gates, and
consequently uses 30 MVs and has an
overall delay of 3 clock cycles (12 clock
zones). Fig. 3: Reversible Logic Unit (RLU)
Table: Functionalities of RLU
Reversible arithmetic unit (RAU)
A full adder can act as an arithmetic unit if
one of the two data lines is controlled. Fig.4
is a 5-input and 2-output circuit with 6
garbage outputs realizing an RAU. The QCA
implementation of the RAU also requires 40
MV s with a delay of 6 clock cycles. RALU is
0
0
0
0
C0
C1
0
0
0
1
C2
0
0
1
0
C3
0
1
1
1
0
0
1
1
1
0
1
1
0
0
1
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
1
1
0
0
0
1
PO
0
A.B
B
A
A XOR
B
A+B
(A+B)'
A
EXNOR
B
A'
B'
(A.B)'
1
Result
AND
COPY
COPY
XOR
OR
NOR
EQUAL
NOT
NOT
NAND
CONSTANT
a 6-input and 2-output circuit with 20 garbage
outputs. QCA implementation of RALU
require 8 RM gate and consequently
require 80 MVs. For page limitation, QCA cell
layouts and its simulation results of RLU,
RAU and RALU, and the schematic diagram
of RALU are not given here. Fig.4: Reversible Arithmetic Unit (RAU)
C0
0
0
0
0
C1
0
0
1
1
C2
0
1
0
1
PO
A
A+1
A+B
A+B+1
1
0
0
A+B
1
1
1
0
1
1
1
0
1
A+B+1
A-1
A
FUNCTION
Transfer A
Increment A
Addition
Addition with carry
1's
complement
Subtraction
2's
complement
Subtraction
Decrement A
Transfer A
Table: Functionalities of RAU
Conclusion
In this work architecture of a 2:1 multiplexer
around QCA (quantum-dot cellular automata)
is introduced considering the primitives
(majority voter). The resulting design consists
of 19 cells covering an area of 0.02 µm2
which is substantially lower than that of
existing designs. It adds to significant
improvements in QCA logic circuit design. A
reversible multiplexer is then synthesized to
explore the design of an efficient reversible
ALU (RALU), in QCA, that out performs the
performance of existing designs.
References
1. K. Kim, K. Wu, R. Karri, 'The Robust QCA
Adder Designs Using Composable QCA
Building Blocks'
2. V. Mardiris, Ch. Mizas, L. Fragidis and V.
Chatzis, 'Design and simulation of a QCA 2
to 1 multiplexer'
3. T. Teodsio and L. Sousa. 'QCA -LG: A tool
for the automatic layout generation of QCA
combinational Circuits'
4. S. Hashemi, M.R. Azghadi, A.
Zakerolhosseini, 'A novel QCA multiplexer
design'
5. A. Roohi, H. Khademolhosseini, S.
Sayedsalehi, 'A Novel Architecture For QCA'
38 AGENT BASED TASK SPECIfiC TEAM FORMATION FOR EFFECTIVE
DISTRIBUTED DECISION MAKING
Arambam James Singh
M Tech Second Year, Department of Information Technology,
Email : [email protected] pp. 1-6, Proceedings of 10th International Conference(IEEE) on Electrical
Engineering/Electronics, Computer, Telecommunications and Information Technology
(ECTI-CON), Krabi, Thailand, May 15-17, 2013
Abstract
Getting solution of a problem by group
discussion is more reliable than getting
solution from a single entity. To increase
reliability of the solution, efficient group of
experts should be formed. Here in this paper
we have proposed a methodology for finding
efficient team of experts for solution of a given
problem collaboratively. The methodology is
conceptualized with the notion of Multiagent
system. We have considered several factors
like Cardinality of team, ability, willingness,
trust and reciprocality of an agent in order to
construct the team. We have also proposed
an optimization function which will be used
to choose most eligible agents to form the
team of experts.
Introduction
In order to get an effective solution of a given
problem, a team of expert agents should be
formed in which all the members are very
much capable and willing as well as highly
trustable. If the number of team members is
very large, then the cost of decision making
increases as large number of message
passing is required but reliability of solution
increases however if number of team member is less, then cost decreases but reliability
also decreases. So to form a team with
maximum reliability of solution and minimum
cost, an optimum team size should be
choosen.
Theory / Model
Let A = { Ai | i ε[1,n] } is a pool of agent.
And Suniv = { Sj | j ε [1,m] } be the universal
set of skills which are required to perform any
task in a particular domian. Each agent Ai
where i ε [1,n] has it’s own skill set SAi
Suniv
in their Knowledge Base(KB). Now suppose
from a user U , a problem P comes to an
agent Ai ε A and suppose Ai identifies the
required skill set to solve the problem. As it
doesn’t have the identified skill set in it’s KB,
it cannot solve it. Thus it forward the skill set
to it’s neighbouring agents for a collaborative
solution and initiate the request for Team
Formation. Now we have to build a group of
expert agents Gf
A which will collaboratively
provide an effective solution of the given
problem P.
Suppose from a user U a problem P of
domain dmi comes to an agent Ai for
solution. Let Ai is not capable of finding the
solution as required skill sets are not in it’s
knowledge base(KB). So agent Ai as a task
provider starts finding a team of expert
agents who can collaboratively make the
solution from pool of agents in domain dmi.
Finding a team of experts can be done in two
phases,
• Phase 1 : Initial Group Formation
• Phase 2 : Final Group Formation
A. Phase 1 : Initial Group Formation
Initially from pool of agents number of expert
agents are selected to form a group Gi. The
group should satisfy the following criterias:1) Wav is maximum: Average Willingness of
the Group should be maximum. It can only be
39 possible if the group contains agent with
maximum willingness value.
2) Cover(Gi ,SP) = SP
3) | Gi | ≤ MAX : In initial group Gi there
should be atmost MAX number of agents.
MAX is defined as an upper limit.
B. Phase 2 : Final Group Formation
skill set SA1 = {P, R, B, E, A}
on
Suniv and so
i [1,|A|].
After getting Initial Group Gi, we move to next
phase i.e. to find Final Group Gf
Gi, We
obtain final group with following criteria:i) Wav is maximum
ii) Tav is maximum
iii) RPav is maximum
iv) | Gf | is minimum : The average index
value of final group should be maximum with
minimum number of agents. Adding or
subtracting more agents decreases average
index value of that group.
Experimental Results and Discussion
In our scenario, we are representing skill
set(S Ai) of an expert software agent Ai as
set of symptoms which are in it’s knowledge
base. For a given skill set SP (here patient’s
symptom set) agent Ai can find possible
disease name if those symptoms of SP are
also present in it’s KB.
Our problem here is to form a team of expert
software agents which are best suited to
perform diagnosis (finding possible diasease)
of a patient with set of symptoms(SP).
Now suppose the patient has following
symptoms:-{Headache(A),
BodyPain(B),
Joint
Pain(C),
Chills(E),
PoorAppetite(F)}.Each symptom is mapped
with an alpha-betic letter, here Headache is
represented as ’A’, Bodypainas ’B’ and
similarly others thus SP = {A, B, C, E, F }
Suppose universal skill set (here symptom
set) contains all possible symptoms of
diaseases named from A to Z represented as
Suniv . So cardinality of universal skill set is
26. Each software agents also have symptom
set in their KB which is subset of universal
skill set. For example suppose agent Ai has
We are simulating this case study of virtual
medical board using JADE tool. We randomly
created the skill sets of each expert agent
present in their respective knowledge bases.
Now LPA initiate the team formation request
using Algorithm1 with MAX = 15 i.e initial
group(Gi ) with 15 members is formed.
Fig2 represents Willingness, Trust and
Reciprocality values of those 15 agents. Fig3
represents Optimal index values(Oi) of each
agents in initial group. Next depending on
optimal index value of agents in Gi, LPA
starts phase 2 i.e final group formation using
Algorithm3. Fig4 represents number of
iterations required to get the optimum
number of members in the final group
depending on average index value of the
group GVi (Gi ) in each iteration. In Fig4
Average index value at 0th iteration is
GV(Gi), we can see that GV value after
removing an agent(with minimum value of Oi)
is more than the previous value and it goes
like this till 4th iteration. At 5th iteration GV
value decreases, so algorithm stops here and
remaining agents in the Initial Group(Gi ) are
considered as the final members of the
group. Hence we get the final group Gf which
are best suited to perform the diagnosis of
the patient. Fig 5 represents optimal index
value of agents in the final group.
Conclusion
In this paper we propose a multi agent based
40 team formation mechanism for a task
considering parameters like cardinality of
team,
willingness,
ability,
trust
and
reciprocality of the agent. We also propose
an optimization function which evaluates the
final team members. Effectiveness of
theteam is determined by the average
willingness, trust and reciprocality of the team
as a whole.
Fig 2
Fig3
Fig 4
Fig5
41 SUPPLIER SELECTION IN RISK ENVIRONMENT: FUZZY INTERVAL
TYPE-2 TOPSIS METHOD
Pritha Das
M.Tech 2011-13, Department of Mathematics
pp. 16-21, Proceedings of International Conference on Advances in Computing and
Communications Technologies, Pattaya, Thailand, January 19-20, 2013
Abstract
An application of unequal weighted fuzzy
multi-attribute decision making method based
interval type-2 TOPSIS method on supplier
selection in a risk oriented supply chain is
discussed. Eight risks evaluative attribute
namely, Performance risk, Demand risk,
Environmental risk, Process risk and
Logistics risk are taken for selecting among
three supplier alternatives. The above fuzzy
based Interval type-2 Topsis method
remarkably reduce the degree of computation
in constructing the average decision matrix
and weighted decision matrix of attributes
enhancing Lee and Chen’ ranking value
approach of trapezoidal interval type-2 fuzzy
sets in selection of alternatives. The result is
consistent, rational, and inventive and
practically proved useful in choosing better
suppliers alternatives in risky supply chain
environment.
Keywords -- Interval type-2 fuzzy sets,
TOPSIS method, ranking weighted decision
matrix, supply chain risk management.
Introduction
In recent years, supply chain has become
more complicated and widespread. As the
organization becomes more dependent on
multi- suppliers, poor decision making
process will lead to excessive delays in
manufacturing and poor customer
side, properly maintaining manufacturer
quality level and delivery schedule. The
overall objective of the selection is to identify
the least risky supplier from the given
alternatives based on decisions of the expert
Decision makers from different fields. In the
process of decision making, due to vague
human nature the information of weights of
the attributes and alternatives relative to
these attributes are given in linguistic terms.
In this paper, we focus our attention on issue
of selection of Tyre Manufacturing companies
in supply chain under uncertain fuzzy
environment,
applying
interval
type-2
TOPSIS method.
Experimental
We consider three Commercial Tyres
Manufacturer companies, in Indian market,
as alternatives, namely “Apollo Tyres” (x1),
“MRF Tyres” (x2), “CEAT Tyres” (x3) and five
risk attributes.
The three decision makers (D1) (Production
Manager),
(D2)
(Economist/statistical
analyst), (D3) (Chemical Engineer) use the
linguistic terms shown in Table 1, to
represent the risk attributes weights, shown
in Table 2 and evaluating values of different
alternatives against different risk attributes
shown in Table 3.
service. In this paper the supplier selection
problem in supply chain takes into account
various risk factors like demand risk,
Performance risk, Environmental risk,
Process risk and Logistics risk, from supplier
42 Results and Discussion
By implementing the aforesaid algorithm with
MATLAB, we have come obtained the order
of risky behavior of the companies as follows:
x₁>x₃>x₂
The quantitative result obtained is shown.
Conclusion
In this paper, we have presented algorithmic
model for fuzzy multiple group decision
making (FMCDM) based on interval type-2
TOPSIS method. Using this approach
decision makers can derive attributes weights
and alternatives weights for total ranking
indices and find the least risky supplier from
given alternatives easily. In the case study,
we have constructed the decision matrices
and weighting decision matrices based on
trapezoidal interval type -2 fuzzy sets and
then present ranking based on ranking
values.
In future, the proposed algorithmic approach
can be applied in other fields as image
processing, machine learning, critical medical
diagnosis, pattern recognition, solving fuzzy
relation equations, function approximation,
equalization of non-linear fading channels,
forecasting of time series etc.
43 2-Π CROSSTALK NOISE MODEL FOR DEEP SUBMICRON
VLSI GLOBAL RC INTERCONNECTS
Saupayan Mazumdar
Fourth year B. Tech. student, Department of Electronics and Communication Engineering
2013 IEEE Conference on Electronics Systems, Designs and Applications (ICEDSA)
Kuala Lumpur, Malaysia
November 05- November 06, 2012
Abstract
In today’s high performance IC design noise
estimation and avoidance are becoming very
important issues. This paper presents a
much improved, highly accurate and efficient
noise model called 2-π model for the
accurate estimation of crosstalk noise. The
proposed model incorporates all the physical
properties including victim and aggressor
drivers, distributed RC characteristics of
interconnects and coupling locations of both
victim and aggressor lines. Then with the
help of this model, expressions for peak
noise and noise width as well as sensitivity
expressions to all model parameters are
calculated. We then use these sensitivity
expressions to analyze and evaluate various
noise avoidance techniques.
the coupling location, at the coupling location
and after the coupling be Ls, Lc and Le,
respectively. The 2-π type reduced RC model
is generated is shown.
Experimental
Introduction
The rapid advances in VLSI technology has
resulted in the reduction of feature size which
affects the crosstalk noise problem and also
affects the design’s timing and functionality
goals [1-2]. This reduction in chip area results
in the performance degradation of VLSI
circuits (eg: logic failure, unwanted coupling
voltage between two adjacent wires, timing
delay etc.)
Theory / Model
For simplicity, we first explain 2-π model for
the case where the victim net is a RC line.
For a victim net with some aggressor nearby,
let the aggressor voltage pulse at the
coupling location be a saturated ramp input
with transition time being tr and the
interconnect length of the victim net before
NOISE AVOIDANCE TECHNIQUES
A. Driver Sizing
Driver sizing can help to reduce the peak
crosstalk noise, since a strong driver is more
capable to sustain a noise spike. Our model
does indicate some situation under which
increasing driver size (i.e., reduce Rd) may
help to reduce the peak noise. It also
indicates the situation under which increasing
driver size may not help to reduce the peak
noise.
B. Wire Spacing
Wire spacing is another way which can
reduce the maximum noise and noise width,
44 with an area penalty. For a wire of fixed
width, its coupling capacitance decreases
while its ground capacitance increases, as its
spacing to a neighbor wire increases. On the
other hand, coupling capacitance of the wire
increases
while
ground
capacitance
decreases, when its spacing to a neighbor
wire decreases.
interconnect decreases with increase in the
physical separation between the signal line
and the shield line. When the signal width
increases, the resistance of the aggressor is
reduced and the coupling noise increases as
shown in Figure 5. The ground capacitance
of the victim line also increases, however,
causing the coupling noise to decrease.
C. Wire Sizing
Wire sizing is another factor which can be
used for maximum noise and noise width
reduction. As the wire’s width is decreased,
its resistance increases and its ground
capacitance decrease. On the other hand, as
the wire’s width is increased its resistance
decreases and its ground capacitance
increases.
D. Noise Amplitude-Width Product
The effective way to reduce amplitude-width
(AW) product are wire spacing, driver sizing
and wire sizing which helps in reducing
noise. A receiver may still be noise immune
even the peak noise exceeds certain
threshold voltage. This can be explained with
the help of amplitude (A) versus width plots,
which can then be transformed into amplitude
(A) versus amplitude-width (AW) product (AAW) plots.
We have generated 150 random circuits
using the parameter ranges presented in
Section 2 and 3 and looked at the sensitivity
of noise peak to each model parameter. The
units are mV/fF for capacitances and mV/Ω
for resistances. Figure 3 shows the scatter
diagram comparing the 2- π model (y-axis)
with HSPICE (x-axis) simulations for 150
randomly generated four-pin nets. HSPICE
simulations are performed on distributed RC
networks by dividing each long wire into
every 100μm segment. The average errors
for peak noise and noise width are 3.43%
and 5.23%, respectively. Table-1 gives the
comparative result of the peak noise voltage
and noise width computed using SPICE and
the proposed method. The peak noise
obtained from the analytical model is
compared to SPICE in terms of the physical
separation between the signal line and the
shield line, as shown in Figure 4. Figure 4
shows the coupling noise for shielded
Conclusion
This paper presents improved 2-π crosstalk
noise model and various noise avoidance
techniques
for
RC
on-chip
VLSI
interconnects. Error presented by this model
is less than 5% on average compared with
SPICE simulation, for both peak noise
voltage and noise width estimation. Results
show that the average error for noise peak is
2.2 % and for the width is 5.2% while
allowing for very fast analysis. The proposed
model can be used to allow time-efficient
accurate analysis of multi conductor line
structures.
45

Students` Intenrational Research Report vol 5 2012-13

Transcription

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