Srinivasa, Narasimha Kini; Dr.Poulose Jacob, K(Cochin University of Science and Technology, May 31, 2002)
[+]
[-]
Abstract:
This thesis attempts to investigate the problems associated with such schemes and suggests a software architecture, which is aimed towards achieving a meaningful discovery. Usage of information elements as a modelling base for efficient information discovery in distributed systems is demonstrated with the aid of a novel conceptual entity called infotron. The investigations are focused on distributed systems and their associated problems. The study was directed towards identifying suitable software architecture and incorporating the same in an environment where information growth is phenomenal and a proper mechanism for carrying out information discovery becomes feasible. An
empirical study undertaken with the aid of an election database of constituencies distributed geographically, provided the insights required. This is manifested in the Election Counting and Reporting Software (ECRS) System. ECRS system is a software
system, which is essentially distributed in nature designed to prepare reports to district administrators about the election counting process and to generate other miscellaneous statutory reports.
Description:
Department of
Computer Science, Cochin University of Science and Technology,
Kini, Srinivasa Narasimha; Dr.Poulose Jacob, K(Cochin University of Science & Technology, 2002)
[+]
[-]
Abstract:
Sharing of information with those in need of it has always been an idealistic goal
of networked environments. With the proliferation of computer networks, information is
so widely distributed among systems, that it is imperative to have well-organized
schemes for retrieval and also discovery. This thesis attempts to investigate the problems
associated with such schemes and suggests a software architecture, which is aimed
towards achieving a meaningful discovery. Usage of information elements as a
modelling base for efficient information discovery in distributed systems is demonstrated
with the aid of a novel conceptual entity called infotron.The investigations are focused on distributed systems and their associated
problems. The study was directed towards identifying suitable software architecture and
incorporating the same in an environment where information growth is phenomenal and a
proper mechanism for carrying out information discovery becomes feasible. An
empirical study undertaken with the aid of an election database of constituencies
distributed geographically, provided the insights required. This is manifested in the
Election Counting and Reporting Software (ECRS) System. ECRS system is a software
system, which is essentially distributed in nature designed to prepare reports to district administrators about the election counting process and to generate other miscellaneous
statutory reports.Most of the distributed systems of the nature of ECRS normally will possess a
"fragile architecture" which would make them amenable to collapse, with the
occurrence of minor faults. This is resolved with the help of the penta-tier architecture
proposed, that contained five different technologies at different tiers of the architecture.The results of experiment conducted and its analysis show that such an
architecture would help to maintain different components of the software intact in an
impermeable manner from any internal or external faults. The architecture thus evolved
needed a mechanism to support information processing and discovery. This necessitated
the introduction of the noveI concept of infotrons. Further, when a computing machine
has to perform any meaningful extraction of information, it is guided by what is termed
an infotron dictionary.The other empirical study was to find out which of the two prominent markup
languages namely HTML and XML, is best suited for the incorporation of infotrons. A
comparative study of 200 documents in HTML and XML was undertaken. The result
was in favor ofXML.The concept of infotron and that of infotron dictionary, which were developed,
was applied to implement an Information Discovery System (IDS). IDS is essentially, a
system, that starts with the infotron(s) supplied as clue(s), and results in brewing the information required to satisfy the need of the information discoverer by utilizing the
documents available at its disposal (as information space). The various components of
the system and their interaction follows the penta-tier architectural model and therefore
can be considered fault-tolerant. IDS is generic in nature and therefore the characteristics
and the specifications were drawn up accordingly. Many subsystems interacted with
multiple infotron dictionaries that were maintained in the system.In order to demonstrate the working of the IDS and to discover the information
without modification of a typical Library Information System (LIS), an Information
Discovery in Library Information System (lDLIS) application was developed. IDLIS is
essentially a wrapper for the LIS, which maintains all the databases of the library. The
purpose was to demonstrate that the functionality of a legacy system could be enhanced
with the augmentation of IDS leading to information discovery service. IDLIS
demonstrates IDS in action. IDLIS proves that any legacy system could be augmented
with IDS effectively to provide the additional functionality of information discovery
service.Possible applications of IDS and scope for further research in the field are
covered.
Description:
Department of
Computer Science, Cochin University of Science and Technology
Siju, Varghese M; Dr.Sarita,Bhat G(Cochin University of Science And Technology, October 11, 2013)
[+]
[-]
Abstract:
The primary habitat of Salmonella is the gastrointestinal tract of
animals and they are discharged into the water bodies through the feces.
Aquatic animals act as asymptomatic reservoirs of a wide range of Salmonella
serotypes. The inevitable delay in the detection of Salmonella contamination
and the low sensitivity of the conventional methods is a serious issue in the
seafood industry. Due to the indiscriminate use, the antibiotics are finally
accumulated in the aquatic environment which provides the required antibiotic
stress for the emergence of more and more antibiotic resistant phenotypes ofSalmonella. Several genetic determinants like integrons, genomic islands etc.
play their role in acquisition and reshuffling of antibiotic resistance genes. A
large number of virulence determinants are required for Salmonella
pathogenicity. The virulence potential of Salmonella is determined, to some
extent, by the presence of phages or phage mediated genes in the bacterial
genome. There is much intra-serotype polymorphism in Salmonella and
epidemiological studies rely on genetic resemblance of the isolated strains.
Proper identification of the strain employing the traditional and molecular
techniques is a prerequisite for accurate epidemiological studies (Soto et al.,
2000).
In this context, a study was undertaken to determine the prevalence of
different Salmonella serotypes in seafood and to characterize them
Description:
Microbial Genetics Laboratory
Department of Biotechnology
Cochin University of Science and Technology
Supriyo,Dey; Dr.Nair, K G(Cochin University of Science and Technology, December 28, 1993)
[+]
[-]
Abstract:
This thesis Entitled Investigations on Broadband planar Dipole Antennas. An antenna is a device ordinarily used for both transmitting and receiving electromagnetic energy. It is an integral part of the radio communication system and accounts for a good deal of progress that has been made in this field during the last few decades.The effect of flaring the dipole arms is studied in Section 4.1. It is observed that the flaring modifies the impedance characteristics of the dipole. In particular, the change in the reactive part of the impedance with frequency is controlled considerably. This improves the 2:1
VSWR bandwidth of the antenna. The effect of various other design parameters on the impedance bandwidth of the antenna are also studied. The important conclusion drawn is that, there is considerable improvement in the impedance bandwidth of the dipole when ground arm dimensions are larger than the main arm dimensions.
Theoretical analysis of various cavity backed antennas are given in Chapter 6. The experimental values agree well with the computation. Also the theory gives a clear inside view and explains the reasons for bandwidth enhancement due to flaring and end-loading of the dipole arms. The percentage bandwidth is determined by calculating the Q of the antenna. Since the approach is for the analysis of microstrip antenna on thick grounded substrate, this method cannot be used to predict the impedance bandwidth of the antennas without cavity backup. Also, the structures analysed are simplified versions of the optimised ones. Specially, the arms overlapping is neglected in the analysis. Also, the antennas with symmetrical arms can only be analysed with this theory.
Description:
Department of Electronics, Cochin
University of Science and Technology
Binoy, Paul; Dr.Girijavallabhan,C P(Cochin University of Science & Technology, February , 2004)
[+]
[-]
Abstract:
Nonlinear optical processes in organic compounds have attracted considerable interest in the field of science and technology because of their compelling technological promises in fields of optical communication,computing,switching and signal processing.As a result of the synthesis of novel organic compounds with varying degree of nonlinear optical strength, many practical devices based on these are getting realised giving new theoretical insights into the nonolinear optical behaviour of materials.Organic compounds like phthalocyanines and porphyrins have evoked great deal of interest in the field of photonic technology.The present thesis describes the results obtained from the investigations carried out on the nonlinear optical properties of certain organo-metallic compounds using Z-Scan and DFWM techniques.
Description:
International School of Photonics,
Cochin University of Science & Technology
Mridula, S; Dr.Mohanan, P(Cochin University Of Science And Technology, July 7, 2005)
[+]
[-]
Abstract:
The thesis relates to the investigations carried out on Rectangular Dielectric
Resonator Antenna configurations suitable for Mobile Communication applications.
The main objectives of the research are to:
- numerically compute the radiation characteristics of a Rectangular DRA
- identify the resonant modes
- validate the numerically predicted data through simulation and experiment
0 ascertain the influence of the geometrical and material parameters upon the
radiation behaviour of the antenna
° develop compact Rectangular DRA configurations suitable for Mobile
Communication applications
Although approximate methods exist to compute the resonant frequency of
Rectangular DRA’s, no rigorous analysis techniques have been developed so far to
evaluate the resonant modes. In this thesis a 3D-FDTD (Finite Difference Time
Domain) Modeller is developed using MATLAB® for the numerical computation of the radiation characteristics of the Rectangular DRA. The F DTD method is a
powerful yet simple algorithm that involves the discretimtion and solution of the
derivative form of Maxwell’s curl equations in the time domain.
Description:
Department of Electronics, Cochin University of Science and
Technology
Deepti Das, Krishna; Dr.Aanandan, C K(Cochin University of Science and Technology, September , 2010)
[+]
[-]
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, we have investigated two major types of wide band
planar antennas: Monopole and Slot. Four novel compact broadband antennas,
suitable for poratble applications, are designed and characterized, namely
1. Elliptical monopole
2. Inverted cone monopole
3. Koch fractal slot
4. Wide band 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 time-domain 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,
Faculty of Technology,
Cochin University of Science and Technology
Suma,M N; Dr.Mohanan, P(Cochin University of Science & Technology, January , 2008)
[+]
[-]
Abstract:
The space constraints on wireless gadgets is a challenge to antenna designers as the ground plane dimensions of the printed monopole significantly affect s the antenna characteristics.Investigations on ground plane truncations have led to the development of an extremely broad band printed monopole antenna.Omnidirectional radiation characteristics with moderate gain makes this antenna highly suitable for mobile/wireless applications .This thesis also highlights the development of UWB printed antenna along with design equations .Optimum ground plane dimensions for compact antenna applications,folding technique for miniaturization and double folding for dual band application are the other highlights of this thesis.
Description:
Department of Electronics,
Cochin University of Science and Technology
Mathiazhagan, A; Dr.Rani,Joseph; Dr.Narayanan, K P(Cochin University of Science & Technology, January , 2011)
[+]
[-]
Abstract:
Brasses are widely used as constructional materials in marine environment due to their anticorrosive,antifouling and mechanical properties.However, its resistance to corrosion and fouling may vary according to local marine environmental condition and the seasons.The dezincification of brass is one of the forms of selective corrosion which has attracted the attention of researchers for the last two decades.Many of the dezincification mechanistic studies have been performed in noncomplex media and hence their conclusions cannot be extended to esturine water,which is of great significance since brass is extensively used in marine environment.Inhibited α brasses are largely immune to dezincication and the effect of tin and arsenic addition to α/beta brasses is not so reliable in controlling the dezincification. There have been many cases of dezincification in duplex brasses in both freshwater and seawater.Though there is some protection methods such as inhibitors,electro deposition and electro polymerization,there is no reliable method of inhibiting the dezincification of two-phase brass.Organic coatings are effectively used for the protection metals due to their capacity to act a physical barrieer between the metal surface and corrosive environment.Hence,pure epoxy coating is selected for this as it has antocorrosiion effect on brass.The dezincification behaviour of brass of the present study has been highlighted in terms of corrosion rate,weight gain/loss,corrosion current and polarization resistence,open circuit potential,dezincification factor. The marine fouling as biomass on brass was assessed and presented in this thesis, The physicochemical properties of estuarine water were correlated with corrosion behaviour of brass.The deterioration of the brass subjected to the effect of estuarine water was also investigated as a measure of loss in mechanical properties such as tensile strength,yield strength,percntage elongation and percentage reduction in area.To validate dezincification data,visual observation,spot analysis,surface morphology before and after removal of corrosion products and corrosion product analysis were performed.The dezincification behavior of epoxy coated brass of the present study has beenhighlighted in terms of corrosion rate ,weight gain/loss,corrosion current and polarization resistance,open circuit potential.dezincification factor.The marine fouling as biomass on epoxy coated brass subjeted to the effect of estuarine water was also investigated as ameasure of loss in mechanical properties such as tensile strength,percentage elongation and percentage reduction in area.The results of dezincification behavior of brass and epoxy coated brass in Cochin estuary water has been presented and discussed.Attempt has been made to correlate the dezincification behavior of brass with epoxy coated brass.
Description:
Dept.of Ship Technology,Cochin University of Science and Technology