Sindhu, M S; Dr.Kannan, B(Cochin University of Science And Technology, July 23, 2013)
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Abstract:
In the current study, epidemiology study is done by means of
literature survey in groups identified to be at higher potential for DDIs as
well as in other cases to explore patterns of DDIs and the factors affecting
them. The structure of the FDA Adverse Event Reporting System (FAERS)
database is studied and analyzed in detail to identify issues and challenges
in data mining the drug-drug interactions. The necessary pre-processing
algorithms are developed based on the analysis and the Apriori algorithm is
modified to suit the process. Finally, the modules are integrated into a tool to identify DDIs. The results are compared using standard drug interaction
database for validation. 31% of the associations obtained were identified to
be new and the match with existing interactions was 69%. This match
clearly indicates the validity of the methodology and its applicability to
similar databases. Formulation of the results using the generic names
expanded the relevance of the results to a global scale. The global
applicability helps the health care professionals worldwide to observe
caution during various stages of drug administration thus considerably
enhancing pharmacovigilance
Description:
Department of Computer Applications, Cochin
University of Science and Technology
Varghese, Paul; Dr.Poulose Jacob, K(Cochin University of Science & Technology, April , 2003)
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Abstract:
The present research problem is to study the existing encryption
methods and to develop a new technique which is performance wise
superior to other existing techniques and at the same time can be very
well incorporated in the communication channels of Fault Tolerant
Hard Real time systems along with existing Error Checking / Error
Correcting codes, so that the intention of eaves dropping can be
defeated. There are many encryption methods available now. Each
method has got it's own merits and demerits. Similarly, many crypt
analysis techniques which adversaries use are also available.
Description:
Department of Computer Science, Cochin University of Science and
Technology
Sonal Kumar, Jain; Dr.Anil, Bhardwaj(Cochin University Of Science And Technology, January , 2013)
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Abstract:
An attempt has been made in this thesis to model some of the emissions observed
by SPICAM and SPICAV on Mars and Venus, respectively, viz., CO Cameron band,
CO+
2 ultraviolet doublet, N2 triplet bands, atomic oxygen green (5577 A), red doublet
(6300, 6364 A), and ultraviolet (2972 A) emissions. One of major sources of these
emissions is photoelectron impact ionization/excitation. In this thesis, an electron
degradation model based on Monte Carlo technique has been developed to calculate
the production/excitation rates of above mentioned emissions due to electron impact.
The limb brightness pro les of emissions are calculated and compared with the observations
wherever available. The e ect of various model input parameters on dayglow
emissions intensities is also evaluated
Description:
Space Physics Laboratory
Vikram Sarabhai Space Centre
Indian Space Research Organisation
Thiruvananthapuram
Rajool Shanis, C P; Pillai, N G K(Cochin University Of Science And Technology, November , 2014)
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Abstract:
The present study is the first attempt to understand population characteristics of the deep-sea pandalid shrimp, P. quasigrandis and to assess the status of these resources off Kerala coast.Total mortality coefficient (Z) of P. quasigrandis estimated by various methods.Natural mortality coefficient (M) calculated was 0.65 and 1.02 by Pauly‟sempirical formula and Srinaths‟s formula respectively
The deep-sea shrimp P. quasigrandis exploited from the present fishing ground and their monetary return has started showing a declining trend. By observing the current yield and economic return, there is no further scope for increasing the catch from the present fishing ground. The study indicated that majority of the deep-sea shrimp trawlers, especially targeted for pandalid shrimps still concentrated off Kollam area (Quilon Bank). Even though researchers had located several potential deep-sea fishing grounds based on exploratory surveys in Indian EEZ , fishermen are unaware of these fishing grounds located and hence sharing the information about new potential deep-sea fishing grounds could avert the possible stock decline due to the intensive targeted deep-sea shrimp fishery in the Quilon Bank. Hence, the present
study recommended that part of the effort from existing fishing grounds may be shifted to newly located deep-sea fishing grounds which will help in a sustainableexploitation of deep-sea resources off Kerala coast.
Jayakrishnan, R; Dr.Vijayakumar, K P(Cochin University of Science & Technology, April , 2008)
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Abstract:
The present thesis can be divided into three areas:1) the
fabrication of a low temperature photo-luminescence and photoconductivity
measuring unit 2) photo-luminescence in the chalcopyrite
CulnSez and CulnS2 system for defect and composition analysis and
3) photo-luminescence and photo-conductivity of In:JS3. This thesis
shows that photo-luminescence is one of most essential semiconductor
characterization tool for a scientific group working on photovoltaics.
Tools which can be robust, non-destructive, requiring minimal sample
preparation for analysis and most informative of the device
applications are sought after by industries and this thesis is towards
establishing photo-luminescence as "THE" tool for semiconductor
characterization. The possible application of photo-luminescence as a
tool for compositional and quality analysis of semiconductor thin
films has been worked upon by this thesis. Photo-conductivity
complement photo-luminescence and together they provide all the
information required for the fabrication of an opto-electronic device.
Description:
Department of Physics,
Cochin University of Science and Technology
George, Sleeba; Dr.Meera Bai,M(Cochin University Of Science And Technology, January , 2004)
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Abstract:
The main objective of the Research was to study the Delayering
scheme implemented in FACT in all its aspects and to examine
wlietlier implementation of delayering has contributed to improvement in
organizational performance by improving managerial motivation and team
effectiveness. To enable this, a post-delayering impact assessment was
done by eliciting views and analyzing the perception of managers
affected by the change programme. Organisation-wide Surveys were
carried out as part of data collection - prior to, during and after implementation. The methodology adopted was the Case Study
approach, which involved a longitudinal study of the
Implementation process using tools such- as Observation, Opinion
surveys and Interviews and relating the research findings with the
theories/ studies on the subject for generalization and for drawing
conclusions
Description:
School of Management Studies
Cochin University of Science and Technology
Saira Joseph; Dr. Binu Paul(Cochin University of Science and Technology, November 20, 2016)
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Abstract:
Over the past decade, there is a great demand for permission to transmit large bandwidth
concurrent with existing narrowband signals. In 2002, the federal communications
commission (FCC) decided to permit use of ultrawideband (UWB) systems.
UWB systems are unique in their large instantaneous bandwidth and potential for lowcost
digital design that enables a single system to operate in different modes as a
communication device, radar etc. UWB systems aim at covering the frequency band of
3.1-10.6 GHz defined by the FCC. The addition of more and more features in each new
generation communication system demands universal antennas suitable for operation in
multiple bands. In this regard, designing a multiband antenna which also covers the
UWB range without deteriorating the UWB performance is of great interest. Also, a
significant issue in communication systems is to miniaturize the antenna size while
providing good performance over the operation bands.
The thesis presents three different designs of CPW-fed multiband antennas. The first
design uses a fractal concept to achieve multiband operation. In the second and third
designs, a slotted circular monopole and a spiral monopole are used respectively for
multiband operation with UWB applications. For both these cases, variations from the
basic antenna geometry are also proposed in which the frequency of operation is
lowered without increase in overall antenna size. Design guidelines are developed for
all antennas to facilitate design on substrates of different permittivity and thickness. The
antennas are analyzed in both frequency and time domain for complete characterization
Sumam, Mary Idicula; Poulose Jacob,K(Cochin University of Science and Technology, 1999)
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Abstract:
This work is aimed at building an adaptable frame-based system for processing Dravidian languages. There are about 17 languages in this family and they are spoken by the people of South India.Karaka relations are one of the most important features of Indian languages. They are the semabtuco-syntactic relations between verbs and other related constituents in a sentence. The karaka relations and surface case endings are analyzed for meaning extraction. This approach is comparable with the borad class of case based grammars.The efficiency of this approach is put into test in two applications. One is machine translation and the other is a natural language interface (NLI) for information retrieval from databases. The system mainly consists of a morphological analyzer, local word grouper, a parser for the source language and a sentence generator for the target language. This work make contributios like, it gives an elegant account of the relation between vibhakthi and karaka roles in Dravidian languages. This mapping is elegant and compact. The same basic thing also explains simple and complex sentence in these languages. This suggests that the solution is not just ad hoc but has a deeper underlying unity. This methodology could be extended to other free word order languages. Since the frame designed for meaning representation is general, they are adaptable to other languages coming in this group and to other applications.
Bindu, M S; Dr.Sumam Mary,Idicula(Cochin University Of Science And Technology, 2012)
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Abstract:
This is a Named Entity Based Question Answering System for Malayalam
Language. Although a vast amount of information is available today in digital
form, no effective information access mechanism exists to provide humans with
convenient information access. Information Retrieval and Question Answering
systems are the two mechanisms available now for information access.
Information systems typically return a long list of documents in response to a
user’s query which are to be skimmed by the user to determine whether they
contain an answer. But a Question Answering System allows the user to state
his/her information need as a natural language question and receives most
appropriate answer in a word or a sentence or a paragraph.
This system is based on Named Entity Tagging and Question Classification.
Document tagging extracts useful information from the documents which will be used
in finding the answer to the question. Question Classification extracts useful
information from the question to determine the type of the question and the way in
which the question is to be answered. Various Machine Learning methods are used to
tag the documents. Rule-Based Approach is used for Question Classification.
Malayalam belongs to the Dravidian family of languages and is one of the
four major languages of this family. It is one of the 22 Scheduled Languages of
India with official language status in the state of Kerala. It is spoken by 40 million
people. Malayalam is a morphologically rich agglutinative language and relatively
of free word order. Also Malayalam has a productive morphology that allows the
creation of complex words which are often highly ambiguous.
Document tagging tools such as Parts-of-Speech Tagger, Phrase Chunker,
Named Entity Tagger, and Compound Word Splitter are developed as a part of
this research work. No such tools were available for Malayalam language. Finite
State Transducer, High Order Conditional Random Field, Artificial Immunity System Principles, and Support Vector Machines are the techniques used for the
design of these document preprocessing tools.
This research work describes how the Named Entity is used to represent
the documents. Single sentence questions are used to test the system. Overall
Precision and Recall obtained are 88.5% and 85.9% respectively. This work can be
extended in several directions. The coverage of non-factoid questions can be
increased and also it can be extended to include open domain applications.
Reference Resolution and Word Sense Disambiguation techniques are suggested as
the future enhancements
Description:
Dept. Of Computer Science
Cochin University Of Science And Technology
David, Peter S; Poulose Jacob,K(Cochin University of Science and Technology, August , 2006)
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Abstract:
The present study shows design and development of a performance evaluation prototype for IT organizations in the context of outsourcing. The main objective of this research is to help an IT organization in the context of outsourcing to realize its current standing, so it can take corrective steps where ever necessary and strive for continuous improvement. Service level management (SLM) process plays a crucial role in controlling the quality provision for IT service. Out sourcing is the process of entrusting the responsibility of providing certain goods and services to an external party. We have tried to identify as many as twenty complexities and categorized in to four headings. Complexities associated with contracts and SLAs,SLM process,SLM organization and complexities due to intrinsic characteristics. In this study it is possible to measure the quality of the performance of an IT organization in an outsourcing environment effectively
Deepu, V; Dr.Mohanan, P(Cochin University of Science & Technology, April , 2009)
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Abstract:
Antennas are indispensable component of any wireless communication
device. An antenna is a transducer between the transmitter
and the free space waves and vice versa. They efficiently transfer
electromagnetic energy from a transmission line into free space.
But the present day communication applications require compact and ultra wide band designs which cannot be catered by simple microstrip based designs. PIFAs have solved the
problem to some extend, but the field of antennas needs more innovative designs
In this thesis the design and development of compact planner antenna are
presented. Emphasis is given to the design of the feed as well as the radiator
resulting in simple compact uniplanar geometries. The Asymmetric coplanar
feed used to excite the antennas is found to be a suitable choice for feeding compact antennas.The main objectives of the study are the design of compact single, dual and multi band antennas with uniplanar
structure and extension of the design for practical GSM/WLAN
applications and Ultra compact antennas using the above techniques and
extension of the design to antennas for practical applications like
RFID/DVB-H. All the above objectives are thoroughly studied. Antennas with ultra
compact dimensions are obtained as a result of the study. Simple equations are
provided to design antennas with the required characteristics. The design equations are verified by designing different antennas for different applications.
Description:
Department of Electronics, Cochin University of Science and Technology
Nijas, C M; Mohanan, P(Cochin University Of Science And Technology, March , 2015)
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Abstract:
The main objective of this thesis is to develop a compact chipless RFID
tag with high data encoding capacity. The design and development of chipless
RFID tag based on multiresonator and multiscatterer methods are presented
first. An RFID tag using using SIR capable of 79bits is proposed. The thesis
also deals with some of the properties of SIR like harmonic separation,
independent control on resonant modes and the capability to change the
electrical length. A chipless RFID reader working in a frequency band of
2.36GHz to 2.54GHz has been designed to show the feasibility of the RFID
system. For a practical system, a new approach based on UWB Impulse Radar
(UWB IR) technology is employed and the decoding methods from noisy
backscattered signal are successfully demonstrated. The thesis also proposes a
simple calibration procedure, which is able to decode the backscattered signal
up to a distance of 80cm with 1mW output power.
Sujith, R; Dr.Mohanan, P(Cochin University of Science and Technology, January , 2012)
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Abstract:
The need of miniaturization in the present day communication industry is
challenging. In the present scenario, printed antenna technology is highly
suitable for wireless communication due to its low profile and other desirable
radiation characteristics. Small monopole type antennas are overruled by
compact small antennas for present day mobile communication applications.
Coplanar waveguides (CPW) are printed on one side of a dielectric
substrate. CPW have attracted the attention of antenna designers due to their
excellent properties like ease of integration with ‘MMIC’, low cost, wide
bandwidth, flexibility towards multiband operation, low radiation leakage and
less dispersion. The requirement of omnidirectional coverage, light weight and
low cost made these CPW fed antennas a good candidate for wireless
applications. The main focus of the thesis is the study of coplanar waveguide
transmission line. Rigorous investigations were performed on both the ground
plane and signal strip of a coplanar waveguide transmission line to create
effective radiation characteristics. Good amount of works have been done to
transform CPW line to antenna suitable for mobile phone applications
Description:
Department of Electronics
Cochin University of Science and Technology
Shameena, V A; Dr.Mohanan, P(Cochin University of Science And Technology, January , 2012)
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Abstract:
In recent years, there is a visible trend for products/services which
demand seamless integration of cellular networks, WLANs and WPANs. This
is a strong indication for the inclusion of high speed short range wireless
technology in future applications. In this context UWB radio has a significant
role to play as an extension/complement to existing cellular/access technology.
In the present work, three major types of ultra wide band planar antennas are
investigated: Monopole and Slot. Three novel compact UWB antennas, suitable for
poratble applications, are designed and characterized, namely
1) Ground modified monopole
2) Serrated monopole
3) Triangular slot
The performance of these designs have been studied using standard simulation
tools used in industry/academia and they have been experimentally verified. Antenna
design guidelines are also deduced by accounting the resonances in each structure.
In addition to having compact sized, high efficiency and broad bandwidth
antennas, one of the major criterion in the design of impulse-UWB systems
have been the transmission of narrow band pulses with minimum distortion.
The key challenge is not only to design a broad band antenna with constant and
stable gain but to maintain a flat group delay or linear phase response in the
frequency domain or excellent transient response in time domain. One of the
major contributions of the thesis lies in the analysis of the frequency and timedomain
response of the designed UWB antennas to confirm their suitability for
portable pulsed-UWB systems. Techniques to avoid narrowband interference by
engraving narrow slot resonators on the antenna is also proposed and their
effect on a nano-second pulse have been investigated
Description:
Department of electronics, Cochin University of Science And Technology
Sreejith, Nair M; Dr.Mohanan, P(Cochin University Of Science And Technology, October 7, 2013)
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Abstract:
With the recent progress and rapid increase in the field of communication, the designs of antennas for small mobile terminals with enhanced radiation characteristics are acquiring great importance. Compactness, efficiency, high data rate capacity etc. are the major criteria for the new generation antennas. The challenging task of the microwave scientists and engineers is to design a compact printed radiating structure having broadband behavior along with good efficiency and enhanced gain. Printed antenna technology has received popularity among antenna scientists after the introduction of planar transmission lines in mid-seventies. When we view the antenna through a transmission line concept, the mechanism behind any electromagnetic radiator is quite simple and interesting. Any electromagnetic system with a discontinuity is radiating electromagnetic energy. The size, shape and orientation of the discontinuities control the radiation characteristics of the system such as radiation pattern, gain, polarization etc. It can be either resonant or non-resonant.
This thesis deals with antennas that are developed from a class of transmission lines known as coplanar strip-CPS, a planar analogy of parallel pair transmission line. The specialty of CPS is its symmetric structure compared to other transmission lines, which makes the antenna structures developed from CPS quite simple for design and fabrication. The structural modifications on either metallic strip of CPS results in different antennas. The first part of the thesis discusses a single band and dual band design derived from open ended slot lines which are very much suitable for 2.4 and 5.2 GHz WLAN applications. The second section of the study is vectored into the development of enhanced gain dipoles. A single band dipole and a wide band enhanced gain dipole suitable for 5.2/5.8 GHZ band and imaging applications are developed and discussed. Last part of the thesis discusses the development of directional UWBs. Three different types of ultra-compact UWBs are developed and almost all the frequency domain and time domain analysis of the structures are discussed.
Description:
Department of Electronics
Cochin University of Science and Technology
Sudheep, Elayidom M; Dr.Sumam Mary,Idicula(Cochin University of Science and Technology, 2012)
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Abstract:
Data mining is one of the hottest research areas nowadays as it has got wide variety of applications in common man’s life to make the world a better place to live. It is all about finding interesting hidden patterns in a huge history data base. As an example, from a sales data base, one can find an interesting
pattern like “people who buy magazines tend to buy news papers also” using data mining. Now in the sales point of view the advantage is that one can place these things together in the shop to increase sales. In this research work, data mining is effectively applied to a domain called placement chance prediction, since taking wise career decision is so crucial for anybody for sure. In India technical manpower analysis is carried out by an organization named National Technical Manpower Information System (NTMIS), established in 1983-84 by India's Ministry of Education & Culture. The NTMIS comprises of a lead centre in the IAMR, New Delhi, and 21 nodal centres located at different parts
of the country. The Kerala State Nodal Centre is located at Cochin University of Science and Technology. In Nodal Centre, they collect placement information by sending postal questionnaire to passed out students on a regular basis. From this raw data available in the nodal centre, a history data base was prepared. Each record in this data base includes entrance rank ranges, reservation, Sector, Sex, and a particular engineering. From each such combination of attributes from the history data base of student records, corresponding placement chances is computed and stored in the history data base. From this data, various popular data mining models are built and tested. These models can be used to predict the most suitable branch for a particular new student with one of the above combination of criteria.
Also a detailed performance comparison of the various data mining models is done.This research work proposes to use a combination of data mining models namely a hybrid stacking ensemble for better predictions. A strategy to predict the overall absorption rate for various branches as well as the time it takes for all the students of a particular branch to get placed etc are also proposed.
Finally, this research work puts forward a new data mining algorithm namely C 4.5 * stat for numeric data sets which has been proved to have competent accuracy over standard benchmarking data sets called UCI data sets. It also proposes an optimization strategy called parameter tuning to
improve the standard C 4.5 algorithm.
As a summary this research work passes through all four dimensions for a typical data mining research work, namely application to a domain, development of classifier models, optimization and ensemble methods.
Description:
Department of Computer Science, Cochin University of Science and Technology
Suresh, Kumar P; Dr. Radhakrishnan, P(Cochin University of Science & Technology, October , 2003)
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Abstract:
In recent years,photonics has emerged as an essential technology related to such diverse fields like laser technology,fiber optics,communication,optical signal processing,computing,entertainment,consumer electronics etc.Availabilities of semiconductor lasers and low loss fibers have also revolutionized the field of sensor technology including telemetry. There exist fiber optic sensors which are sensitive,reliable.light weight and accurate devices which find applications in wide range of areas like biomedicine,aviation,surgery,pollution monitoring etc.,apart from areas in basic sciences.The present thesis deals with the design,fabrication and characterization of a variety of cost effective and sensitive fiber optic sensors for the trace detetction of certain environment pollutants in air and water.The sensor design is carried out using the techniques like evanescent waves,micro bending and long period gratings.
Description:
International School of Photonics,
Cochin University of Science and Technology
Reji Kumar, R; Dr. Jacob, Philip(Cochin University of Science and Technology, December , 2009)
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Abstract:
Hevea latex is a natural biological liquid of very complex composition .Besides rubber hydrocarbons,it contains many proteinous and resinous substances,carbohydrates,inorganic matter,water,and others.The Dry Rubber Content (DRC) of latex varies according to season, tapping system,weather,soil conditions ,clone,age of the tree etc. The true DRC of the latex must be determined to ensure fair prices for the latex during commercial exchange.The DRC of Hevea latex is a very familiar term to all in the rubber industry.It has been the basis for incentive payments to tappers who bring in more than the daily agreed poundage of latex.It is an important parameter for rubber and latex processing industries for automation and verious decesion making processes.This thesis embodies the efforts made by me to determine the DRC of rubber latex following different analytical tools such as MIR absorption,thermal analysis.dielectric spectroscopy and NIR reflectance.The rubber industry is still Looking for a compact instrument that is accurate economical,easy to use and environment friendly.I hope the results presented in this thesis will help to realise this goal in the near future.
Description:
Department of Instrumentation,
Cochin University of Science and Technology
Raphika, P. M.; Dr. Abdulla P.(Cochin University of Science and Technology, May 3, 2016)
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Abstract:
Filters are one of the essential components in the RF and wireless
communication systems. Small sized planar lowpass filters with good electrical
characteristics along with low cost, light weight and ease of fabrication are highly
desirable for the front end of modern communication systems to suppress harmonics
and spurious signals. Design of compact lowpass filters with improved performance
and diverse specifications for numerous applications is a huge challenge.
In this thesis, high performance planar compact lowpass filters using multiple
patch resonators on high impedance transmission line are developed. Design techniques
of different types of patch resonators and their modifications to enhance the
performance of the filters are presented.Patch resonators are designed by using high impedance short circuited stubs
and low impedance open circuited patches. In the first stage of filter realization,
compact lowpass filter having sharp roll-off using triangular and funnel patch
resonators is presented. The structure is modified further to enhance the relative
stopband bandwidth of the filter. In the third stage, another resonator has been
introduced near the feed line to achieve sharp roll-off for the same cutoff frequency,
stopband bandwidth and suppression level. To obtain compactness, high suppression
level and wide stopband in filter design, low thickness substrate is tested and proved in
the fourth stage.
Realizations of planar compact lowpass filter with very sharp roll-off near the
cutoff frequency have been presented using stepped impedance polygonal patch
resonators. By increasing the patch size and number of resonators, the stopband
bandwidth and suppression level have to be enhanced to a great extent. Enhancement
of performance characteristics of lowpass filter design is continually being extended.
By using high value capacitance patch, the stopband suppression level of the filter with
sharp roll-off rate is achieved. Elliptic function lowpass filter with ultra-sharp roll-off is
also developed using elliptic shaped patch resonators.
Throughout the study, low cost substrate having permittivity 4.4 is used for the
filter design. All the designed filters have been fabricated and predicted results are
validated by the measurements.
Nishamol, M S; Dr.Vasudevan, K(Cochin University of Science and Technology, January 4, 2012)
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Abstract:
Antennas are necessary and vital components of communication and radar systems, but sometimes their inability to adjust to new operating scenarios can limit system performance. Reconfigurable antennas can adjust with changing system requirements or environmental conditions and provide additional levels of functionality that may result in wider instantaneous frequency bandwidths, more
extensive scan volumes, and radiation patterns with more desirable side lobe distributions. Their agility and diversity created new horizons for different types of applications especially in cognitive radio, Multiple Input Multiple Output Systems, satellites and many other applications. Reconfigurable antennas satisfy the requirements for increased functionality, such as direction finding, beam steering,
radar, control and command, within a confined volume. The intelligence associated with the reconfigurable antennas revolved around switching mechanisms utilized. In the present work, we have investigated frequency reconfigurable polarization diversity antennas using two methods: 1. By using low-loss, high-isolation switches such as PIN diode, the antenna can be structurally reconfigured to maintain the elements near their resonant dimensions for different frequency bands and/or polarization.
2. Secondly, the incorporation of variable capacitors or varactors, to overcome many problems faced in using switches and their biasing. The performances of these designs have been studied using standard simulation tools used in industry/academia and they have been experimentally verified. Antenna design guidelines are also deduced by accounting the resonances. One of the major contributions of the thesis lies in the analysis of the designed antennas using FDTD based numerical computation to validate their performance.
Description:
Department of Electronics, Cochin University of Science and Technology
Dinesh, R; Dr Mohanan, P(Cochin University of Science and Technology, April , 2015)
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Abstract:
The main objective of this thesis is to design and develop spectral signature
based chipless RFID tags Multiresonators are essential component of
spectral signature based chipless tags. To enhance the data coding capacity in
spectral signature based tags require large number of resonances in a limited
bandwidth. The frequency of the resonators have to be close to each other.
To achieve this condition, the quality factor of each resonance needs to be
high. The thesis discusses about various types of multiresonators, their practical
implementation and how they can be used in design. Encoding of data
into spectral domain is another challenge in chipless tag design. Here, the
technique used is the presence or absence encoding technique. The presence
of a resonance is used to encode Logic 1 and absence of a speci c resonance is
used to encode Logic 0. Di erent types of multiresonators such as open stub
multiresonators, coupled bunch hairpin resonators and shorted slot ground
ring resonator are proposed in this thesis.
Ramkumar, S; Dr.Vijayakumar, K P(Cochin University of Science & Technology, January , 2006)
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Abstract:
In this work we present the results of our attempt to build a compact
photothermal spectrometer capable of both manual and automated mode of
operation.The
salient features of the system include the ability to analyse thin film, powder
and polymer samples. The tool has been in use to investigate thermal, optical
and transport properties. Binary and ternary semiconducting thin films were
analysed for their thermal diffusivities. The system could perform thickness
measurements nondestructively. Ion implanted semiconductors are widely
studied for the effect of radiation induced defects. We could perform
nondestructive imaging of defects using our spectrometer.The results reported in his thesis on the above in
addition to studies on In2S3 and transparent conducting oxide ZnO have been
achieved with this spectrometer. Various polymer samples have been easily
analysed for their thermal diffusivities. The technique provided ease of
analysis not achieved with conventional techniques like TGA and DSC.
Industrial application of the tool has also been proved by analyzing defects of
welded joints and adhesion of paints. Indigenization of the expensive lock-in-amplifier
and automation has been the significant achievement in the course of
this dissertation. We are on our way to prove the noise rejection capabilities of
our PC LIA.
Description:
Department of Physics,
Cochin University of Science and Technology
Baby Paul; Dr. P. Mythili(Cochin University of Science and Technology, October 8, 2015)
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Abstract:
Electrocardiogram gives the information regarding the health of
the patients by monitoring the bioelectric potentials generated by the
sinoatrial node in the heart. These signals can be collected by using
electrodes suitably placed on the body of a patient. The normal human
ECG lie in the frequency range of 0.05-100 Hz and the most useful
information is contained in the range of 0.5-45 Hz. Even though a large
amount of work has already been done in the field of ECG classification,
no classification system has made an attempt in identifying the isolated
abnormalities which pose a silent threat to patients.
An adaptive filtering technique for denoising the ECG which is
based on Genetic Algorithm (GA) tuned Sign-Data Least Mean Square
(SD-LMS) algorithm is proposed. This algorithm gave an average
signal to noise ratio improvement of 10.75 dB for baseline wander and
24.26 dB for power line interference. It is seen that the step size ‘μ’
optimized with GA helps in obtaining better SNR value without causing
any damage to the information content in the ECG.
A new wavelet for automatic classification of arrhythmias
from electrocardiogram is proposed. This new wavelet is formed as a
sum of shifted Gaussians so that it resembles a normal ECG. This shape
has been chosen with the aim of extracting maximum information from
the ECG under analysis. The classification performance was studied
using the most commonly used database, the MIT-BIH Arrhythmia
database. The shifted and summed Gaussian wavelet was then
optimized using GA. The optimum wavelet for classification was
obtained after several runs of the GA algorithm. The ECG class
labeling was done according to the Association for the Advancement of
Medical Instrumentation (AAMI). The wavelet scales corresponding to
the different frequency levels giving maximum classification
performance were identified by selecting finer scales. Probabilistic
Neural Network classifier was used for classification purpose. The
proposed classification system offered better results than that reported
in literature by giving an overall sensitivity of 97.01% for Normal beats,
75.20% for Supraventricular beats and 93.06% for Ventricular beats.
As mentioned above this technique could exclusively identify some of
the isolated abnormalities present in the patient records.