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