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.
Sudha Kartha, C; Vijayakumar, K P; Rajeshmon, V G; Vimalkumar, T V; Poornima, N(Hindawi Publishing Corporation, January 6, 2013)
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Abstract:
This work projects photoluminescence (PL) as an alternative technique to estimate the order of resistivity of zinc oxide (ZnO) thin
films. ZnO thin films, deposited using chemical spray pyrolysis (CSP) by varying the deposition parameters like solvent, spray rate,
pH of precursor, and so forth, have been used for this study. Variation in the deposition conditions has tremendous impact on the
luminescence properties as well as resistivity. Two emissions could be recorded for all samples—the near band edge emission (NBE)
at 380 nm and the deep level emission (DLE) at ∼500 nm which are competing in nature. It is observed that the ratio of intensities
of DLE to NBE (𝐼DLE/𝐼NBE) can be reduced by controlling oxygen incorporation in the sample. 𝐼-𝑉 measurements indicate that
restricting oxygen incorporation reduces resistivity considerably. Variation of 𝐼DLE/𝐼NBE and resistivity for samples prepared under
different deposition conditions is similar in nature. 𝐼DLE/𝐼NBE was always less than resistivity by an order for all samples.Thus from
PL measurements alone, the order of resistivity of the samples can be estimated.
Description:
International Journal of Photoenergy
Volume 2013, Article ID 105796, 9 pages
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.
Girish Kumar,K; Saji John,Konnully(Department of Applied Chemistry, August 1, 2006)
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Abstract:
Salicylaldehyde Schiff base of amino-methylated
polystyrene has been developed as a novel reagent for the removal
of Fe(III) from solutions. The selectivity of the metal
ion uptake over a wide range of different concentrations of
metal ion, effect of pH, ligand concentration and the influence
of other foreign ions were studied. A very good selectivity
was achieved for the removal of the ion. It was found
that 0.01 g of the ligand was sufficient to achieve about 96%
removal of the metal ion in terms of concentration (ppm)
from a 30 ppm solution in acidic pH.
Sunoj, S M; Asok, Nanda K; Sankaran, P G(Elsevier, December 4, 2013)
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In the present paper, we introduce a quantile based Rényi’s entropy function and its residual
version. We study certain properties and applications of the measure. Unlike the residual
Rényi’s entropy function, the quantile version uniquely determines the distribution
Description:
Statistics and Probability Letters 85 (2014) 114–121
Ajitha Kumar, B S; Dr.Alagarswami, K(Cochin University of Science And Technology, March , 1984)
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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
Santhosh Kumar, G(Cochin University of Science And Technology, October 18, 2013)
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Abstract:
Cyber Physical systems (CPS) connect the physical world with cyber world. The events
happening in the real world is enormous and most of it go unnoticed and information is lost.
CPS enables to embed tiny smart devices to capture the data and send it to Internet for
further processing. The entire set-up call for lots of challenges and open new research
problems. This talk is a journey through the landscape of research problems in this
emerging area.
A simple technique for calculating the resonance frequencies of a
compact arrow-shaped microstrip antenna is presented and discussed . The accuracy of the method is validated by experimental results
Paulson,M; Sona,Kundukulam O; Aanandan,C K; Mohanan, P(Department of Electronics, September , 2001)
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Abstract:
The arrow shaped microstrip antenna, which produces
dual frequency dual polarisation operation with considera-ble size reduction compared to conventional patches has been
reported [I]. These antennas provide greater area reduction and
improved gain compared to drum shaped patches [2]. Prediction
of the resonance frequency of drum shaped patches [3] and circular
patches for broadband operation [4] are available in the literature.
In this Letter, we propose empirical formulas for calculating
the resonance frequencies of the arrow shaped microstrip antenna.
These antennas can be employed for obtaining dual frequency
with the same polarisation, bandwidth enhancement, circular
polarisation etc. by varying its different parameters or by introducing
slots. The proposed design equations provide an easier and
simple way of predicting the resonant frequencies of these patches.
Sona,Kundukulam O; Paulson,M; Aanandan,C K; Mohanan, P; K G Nair(Department of Electronics, October , 2002)
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A dual-port microstrip antenna with a crescent shaped
patch with excellent isolation betwecn the ports has been reportcd [I].
Since circular-sided geometries are inore compact than rectangular
oncs, thcy find morc applications in microstrip arrays. The crcscent
shaped antenna geometry [ I ] provides greater area rcductioii compared
to other circular sided patches for broadband operation [2]. In this
Lctter, formulac for calculating thc TM, I and TMZI mode resonant
frequencies of this microstrip antenna, obtained by modifying the
equations of a standard circular patch [3] are presentcd. Thcorctical
results are compared with experimental observations aid the validity
of the computation is established.
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