Sreedevi, Menon K; Vasudevan, K; Aanandan,C K; Mohanan, P(Microwave and Optical Technology Letters, September 20, 2005)
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Abstract:
Propagation of electromagnetic waves through a microstrip
line with 2D electromagnetic baud gap (EBG) structures of different
geometrical shapes in the ground plane is investigated in this paper.
Using transmission-line theory, the design equations for EBG structures are calculated. The measured, numerical. and simulated results are in
gone) agreement
Jagathy Raj, V P; Praveen, R P; Ravichandran, M H; Sadasivan Achari, V T; Madhu, G; Bindu, G R(IEEE, September 10, 2011)
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Abstract:
This paper presents the optimal design of a sur-
face mounted permanent magnet Brushless DC mo-
tor (PMBLDC) meant for spacecraft applications.
The spacecraft applications requires the choice of a
torques motor with high torque density, minimum
cogging torque, better positional stability and high
torque to inertia ratio. Performance of two types
of machine con¯gurations viz Slotted PMBLDC and
Slotless PMBLDC with halbach array are compared
with the help of analytical and FE methods. It is
found that unlike a Slotted PMBLDC motor, the
Slotless type with halbach array develops zero cogging
torque without reduction in the developed torque.
Moreover, the machine being coreless provides high
torque to inertia ratio and zero magnetic stiction
Description:
ECTI TRANSACTIONS ON ELECTRICAL ENG., ELECTRONICS, AND COMMUNICATIONS VOL.9, NO.1 February 2011
Sumam, Mary Idicula; Anuja, K; Suryapriya., S(IEEE, 2009)
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Abstract:
This paper presents the design and
development of a frame based approach for speech to
sign language machine translation system in the domain
of railways and banking. This work aims to utilize the
capability of Artificial intelligence for the improvement
of physically challenged, deaf-mute people. Our work
concentrates on the sign language used by the deaf
community of Indian subcontinent which is called
Indian Sign Language (ISL). Input to the system is the
clerk’s speech and the output of this system is a 3D
virtual human character playing the signs for the
uttered phrases. The system builds up 3D animation
from pre-recorded motion capture data. Our work
proposes to build a Malayalam to ISL
Description:
2009 World Congress on Nature & Biologically Inspired Computing (NaBIC 2009)
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
Suresh, Kumar P; Thomas Lee, S; Vallabhan, C P G; Nampoori, V P N; Radhakrishnan, P(Elsevier, 2002)
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Abstract:
The design and development of a cost-effective, simple, sensitive and portable LED based fiber optic evanescent wave sensor for simultaneously detecting trace amounts of chromium and nitrite in water are presented. In order to obtain the desired performance, the middle portions of two multimode plastic clad silica fibers are unclad and are used as the sensing elements in the two arms of the sensor. Each of the sensor arms is sourced by separate super bright green LEDs, which are modulated in a time-sharing manner and a single photo detector is employed for detecting these light signals. The performance and characteristics of this system clearly establish the usefulness of the technique for detecting very low concentrations of the dissolved contaminants.
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
James, Kurian; Subramaniam, M P; Saseendran Pillai, P R(IEEE, September 22, 2003)
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Abstract:
For the scientific and commercial utilization of Ocean resources, the role of
intelligent underwater robotic systems are of great importance. Scientific activities like
Marine Bio-technology, Hydrographic mapping, and commercial applications like Marine
mining, Ocean energy, fishing, aquaculture, cable laying and pipe lining are a few utilization
of ocean resources. As most of the deep undersea exploration are beyond the reachability of
divers and also as the use of operator controlled and teleoperated Remotely Operated Vehicles (ROVs)
and Diver Transport Vehicles (DTVs) turn out to be
highly inefficient, it is essential to have a fully
automated system capable providing stable control
and communication links for the unstructured
undersea environment.
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