Vineshkumar, B; Dr.Unnikrishnan Nair, N(Cochin University of Science and Technology, May 30, 2012)
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Abstract:
Reliability analysis is a well established branch of statistics that deals with the statistical study of different aspects of lifetimes of a system of components. As we pointed out earlier that major part of the theory and applications in connection with reliability analysis were discussed based on the measures in terms of distribution function. In the beginning chapters of the thesis, we have described some attractive features of quantile functions and the relevance of its use in reliability analysis. Motivated by the works of Parzen (1979), Freimer et al. (1988) and Gilchrist (2000), who indicated the scope of quantile functions in reliability analysis and as a follow up of the systematic study in this connection by Nair and Sankaran (2009), in the present work we tried to extend their ideas to develop necessary theoretical framework for lifetime data analysis. In Chapter 1, we have given the relevance and scope of the study and a brief outline of the work we have carried out. Chapter 2 of this thesis is devoted to the presentation of various concepts and their brief reviews, which were useful for the discussions in the subsequent chapters .In the introduction of Chapter 4, we have pointed out the role of ageing concepts in reliability analysis and in identifying life distributions .In Chapter 6, we have studied the first two L-moments of residual life and their relevance in various applications of reliability analysis. We have shown that the first L-moment of residual function is equivalent to the vitality function, which have been widely discussed in the literature .In Chapter 7, we have defined percentile residual life in reversed time (RPRL) and derived its relationship with reversed hazard rate (RHR). We have discussed the characterization problem of RPRL and demonstrated with an example that the RPRL for given does not determine the distribution uniquely
Description:
Department of Statistics, Cochin University of Science and Technology
Shelbi, Joseph; Dr.Jagathy Raj, V P(Cochin University of Science And Technology, June , 2014)
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Abstract:
Software systems are progressively being deployed in many facets
of human life. The implication of the failure of such systems, has an
assorted impact on its customers. The fundamental aspect that supports a
software system, is focus on quality. Reliability describes the ability of
the system to function under specified environment for a specified
period of time and is used to objectively measure the quality. Evaluation
of reliability of a computing system involves computation of hardware
and software reliability. Most of the earlier works were given focus on
software reliability with no consideration for hardware parts or vice
versa. However, a complete estimation of reliability of a computing
system requires these two elements to be considered together, and thus
demands a combined approach. The present work focuses on this and
presents a model for evaluating the reliability of a computing system.
The method involves identifying the failure data for hardware
components, software components and building a model based on it, to
predict the reliability. To develop such a model, focus is given to the
systems based on Open Source Software, since there is an increasing
trend towards its use and only a few studies were reported on the
modeling and measurement of the reliability of such products. The
present work includes a thorough study on the role of Free and Open
Source Software, evaluation of reliability growth models, and is trying
to present an integrated model for the prediction of reliability of a
computational system. The developed model has been compared with
existing models and its usefulness of is being discussed.
Chiranjivi Jayaram,Ch V; Dr. Balchand, A N(Cochin University of Science & Technology, May , 2011)
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Abstract:
In this thesis, a variety of available satellite data products have been made use of
to bring out a synergistic analysis on the upwelling phenomenon in SEAS. Basic
concepts of remote sensing, upwelling and linked oceanography topics have been
dealt in this work .Auxiliary data products utilized in this study are described
in chapter 2. The climatological monthly variability of the upwelling signatures
are detailed under chapter 3. Chapter 4 presents the forcing factors that trigger
the upwelling process in SEAS. Chapter 5 describes the oceanic response to the
forcing factors with respect to the SST cooling and CHLA blooms. Chapter 6
presents the heat budget of the region and the variability of heat budget terms
with respect to upwelling. Chapter 7 describes the inter-annual variability of
upwelling intensity in SEAS and the influence of climatic events on upwelling.
Ajitha Kumar, B S; Dr.Alagarswami, K(Cochin University of Science And Technology, March , 1984)
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Abstract:
This thesis deals with the reproductive physiology of the two species of Indian sea mussels, namely the brown mussel perna indica and the green mussel p viridis .The major aspects of the study include ecophysiology of reproduction linking up the animal reproductive cycle of the animals with the ecological conditions of the natural mussel beds, biochemical and histochemical changes associated with reproduction and neurosecretory cycle in synchrony with the reproductive cycle. Some basic studies on gamete morphology and certain aspects of gamete physiology have been taken up. The experimental work deals with the influence of different feeding levels on gamatogenesis and maturation and the effect of ganglia ablation on spawning. The material for the investigation on perna indica were collected from the natural mussel beds at Vizhinjam near Trivandrum and on p.viridic from Elathur, near Calicut. The period of observation extended from October 1981 to December 1982.
Description:
Central marine fisheries research institute, Cochin University of Science And Technology
Pramod,P K; Dr.Ramachandran,A(Cochin University of Science and Technology, June , 2006)
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Abstract:
This thesis Entitled Resource abundance and survival of indigenous ornamental fishes of central kerala with emphasis on handling and packing stress in puntius filamentosus (valenciennes).Kerala state is endowed with 41 west flowing and three east flowing rivers originating in the Western Ghats. These rivers and their vast network of tributaries and distributaries harbour rich and diversified fish fauna. Most of the freshwater fishes available in Kerala are highly appreciated as ornamental fishes in the national and international markets.Today the ornamental fish industry is one of the largest industries all over the world. The demand for ornamental fishes has been increasing steadily with the enlargement of the industry, such that the current demand for indigenous ornamental fishes have exceeded the supply. This has led to serious concern about the resources available in the country that can be utilised judiciously for the economic benefit of the state. With an aim to fill up the lacuna, a database of freshwater ornamental fishes of Kerala was created as part of the present study. Ornamental fishes destined for export marketing should thrive well in the aquarium conditions.The study reiterates fishes caught from different environmental conditions and feeding habits have a greater ability to adapt
and acclimatise to an entirely new environment and food habits.
Marketing studies based on the statistics available with Marine Products Export Development Authority show that these species are not being exported at the required level over the past 6 years,
when compared to the availability in the water bodies of Kerala. Sustainable utilisation of these resources from the wild using modern management principles and code of conduct for responsible fishing are advisable until captive breeding technology is popularised.
Description:
School of Industrial Fisheries, Cochin University of Science and Technology
Archana, S N; Humayoon Kabir, S(Cochin University of Science And Technology, May , 2014)
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Abstract:
There are around 150 engineering colleges (ECs) in Kerala
under the government, aided and self financing (S.F.) sectors. While
the college libraries in the government and aided sectors receive
several grants, the libraries of S.F. colleges are solely run by their
own funds. The rising costs of scholarly publications and strict
AICTE stipulations regarding libraries and their collection, pose
great difficulties to the libraries in all sectors in finding adequate
budgets to provide quality services. Library cooperation/resource
sharing helps to overcome this problem to a considerable extent.
The present study analysed the facilities and services of the
ECs affiliated to M.G.University, Kerala to identify whether there is
a need for resource sharing (RS) among these libraries. The
satisfaction of the users with their library resources and services
were also ascertained. The study put forward a model for RS and the
opinion of the librarians and users regarding the same were
collected. Structured questionnaires were used to collect the required
data.
The study revealed that a wide gap exist between the libraries
with respect to their facilities and services and many of the S.F.
libraries have better infrastructure when compared to the
government and aided college libraries. Majority of the respondents
opined that RS is necessary to satisfy their information needs. The
model of RS proposed by the study was widely accepted by the
librarians and users. Based on the opinions and suggestions of the
respondents, the study developed the potential model for resource
sharing- the Virtual Resource Sharing Centre (VRSC).
Thara, K J; Dr. Sajeev, R(Cochin University of Science & Technology, July , 2011)
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Abstract:
The thesis attempts to study the changes in oceanographic parameters associated with extreme climatic events,the influence of oceanographic as well as meteorological parameters on fishes.The characteristics of major pelagic fishes of southwest coast of India(Oil sardine and Indian mackerel) have been described here.A description on study area and period of study is also described .The impact of extreme climatic events on the oceanographic variability of Eastern Arabian Sea.The extreme climatic event,the Indian Ocean Dipole associated with EI Nino Southern Oscillation is taken into consideration.The variability in oil sardine and mackerel landings of southwest coast of India during the study period.The trend analysis of the landings has been done and also a prediction model is applied for the landings.The influence of environmental parameters on oil sardine as well as mackerel fishery has been explained .With regression analysis ,the significant relation between environmental parameters and fish landings are also been recognized.The prediction of landings is done with these environmental parameters.
Description:
Dept.of Physical Oceanography,Cochin University of Science and Technology
Varghese,Joshua C; Krishnamoorthy,A(Department of Mathematics, 2003)
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Abstract:
Queueing system in which arriving customers who find all servers and waiting positions (if any) occupied many retry for service after a period of time are retrial queues or queues with repeated attempts. This study deals with two objectives one is to introduce orbital search in retrial queueing models which allows to minimize the idle time of the server. If the holding costs and cost of using the search of customers will be introduced, the results we obtained can be used for the optimal tuning of the parameters of the search mechanism. The second one is to provide insight of the link between the corresponding retrial queue and the classical queue. At the end we observe that when the search probability Pj = 1 for all j, the model reduces to the classical queue and when Pj = 0 for all j, the model becomes the retrial queue. It discusses the performance evaluation of single-server retrial queue. It was determined by using Poisson process. Then it discuss the structure of the busy period and its analysis interms of Laplace transforms and also provides a direct method of evaluation for the first and second moments of the busy period. Then it discusses the M/ PH/1 retrial queue with disaster to the unit in service and orbital search, and a multi-server retrial queueing model (MAP/M/c) with search of customers from the orbit. MAP is convenient tool to model both renewal and non-renewal arrivals. Finally the present model deals with back and forth movement between classical queue and retrial queue. In this model when orbit size increases, retrial rate also correspondingly increases thereby reducing the idle time of the server between services
Asha, A S; Dr.Jayaraj, M K(Cochin University of Science & Technology, December , 2007)
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Abstract:
The main objective of this thesis work is to optimize the growth conditions for
obtaining crystalline and conducting Lao.5Sro.5Co03 (LSCO) and
Lao.5Sro.5Coo.5.5Nio.5O3 (LSCNO) thin films at low processing temperatures. The
films are prepared by radio frequency magnetron sputtering under various
deposition conditions. The thin films were used as electrodes for the fabrication
of ferroelectric capacitors using BaO.7SrO.3 Ti03 (BST) and PbZro.52 Tio.4803 (PZT).
The structural and transport properties of the La1_xSrxCo03 and Lao.5Sro.5Co1_xNix03
are also investigated. The characterization of the bulk and the thin films were
performed using different tools. A powder X-ray diffractometer was used to
analyze the crystalline nature of the material. The transport properties were
investigated by measuring the temperature dependence of resistivity using a four
probe technique. The magnetoresistance and thermoelectric power were also used to investigate the transport properties. Atomic force microscope was used
to study the surface morphology and thin film roughness. The ferroelectric
properties of the capacitors were investigated using RT66A ferroelectric tester.
Description:
Department of Physics,
Cochin University of Science and Technology