Subin Thomas; Dr. K. Rajeev Kumar(Cochin University of Science and Technology, November 11, 2015)
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Abstract:
The semiconductor industry's urge towards faster, smaller and cheaper
integrated circuits has lead the industry to smaller node devices. The integrated
circuits that are now under volume production belong to 22 nm
and 14 nm technology nodes. In 2007 the 45 nm technology came with
the revolutionary high- /metal gate structure. 22 nm technology utilizes
fully depleted tri-gate transistor structure. The 14 nm technology is a
continuation of the 22 nm technology. Intel is using second generation
tri-gate technology in 14 nm devices. After 14 nm, the semiconductor industry
is expected to continue the scaling with 10 nm devices followed by
7 nm. Recently, IBM has announced successful production of 7 nm node
test chips. This is the fashion how nanoelectronics industry is proceeding
with its scaling trend.
For the present node of technologies selective deposition and selective removal
of the materials are required. Atomic layer deposition and the
atomic layer etching are the respective techniques used for selective deposition
and selective removal. Atomic layer deposition still remains as
a futuristic manufacturing approach that deposits materials and lms in
exact places. In addition to the nano/microelectronics industry, ALD is
also widening its application areas and acceptance. The usage of ALD
equipments in industry exhibits a diversi cation trend. With this trend,
large area, batch processing, particle ALD and plasma enhanced like ALD
equipments are becoming prominent in industrial applications. In this
work, the development of an atomic layer deposition tool with microwave
plasma capability is described, which is a ordable even for lightly funded
research labs.
Terry Mechado; Dr.Seralathan, P(Cochin University Of Science And Technology, April 12, 1995)
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Abstract:
Continental shelf is of particular significance in marine geology ,
because it links the two basically different structural zones in the earth's crust; the
continents and ocean basins. The shelf area has much wider importance in many
fields of activity such as scientific, economic, social, political and strategic. The
pace of development has ultimately put pressure on mankind to look for exploitable
resources and accessibility to the continental shelf area and beyond. Added to the
above, the developmental activities in the coastal area would readily and directly
influence the innershelf sediments. This situation demands a thorough geological
knowledge of the continental shelf area. Moreover, a successful management of
the continental shelf zone requires an optimum data base on the physico-chemical
nature of the shelf sediments. Although sedimentological studies were carried out
along the western continental shelf of India, a well documented systematic study
of the inner shelf off Trivandrum coast is still found to be lacking. Considering the
physiographic settings and the vicinity of two renowned placer deposits at Chavara
and Manavalakurichi, such a sedimetological inventory has become all the more
vital.
In view of the above, a research programme has been drawn up to
account the salient sedimentological and mineralogical aspects of the innershelf
and beach sediments between Paravur and Kovalam, Trivandrum district, Kerala
(latitudes 8° 7'00" to 8° 47'45" and longitudes 76°43'00" to 77° 40'45"). The
findings are presented in six chapters formatted to address the aim of this
research.
Description:
Marine Geology Division
School of Marine Sciences
Cochin University of Science And Technology
Maheswaran, P A; Revichandran, C(NATIONAL INSTITUTE OF OCEANOGRAPHY, August , 2004)
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Abstract:
In this thesis, a detailed attempt has been made to understand the general hydrography of the upper 300m of the water column, in the eastern Arabian Sea and the western Bay of Bengal, the two contrasting basins in the northern Indian Ocean, using recently collected data sets of Marine Research-Living Resources (MR-LR) assessment programme, funded by Department of Ocean Development, from various cruises, pertaining to different seasons. Initially it discuss the general hydrography of the west and east coasts of India are covered, in the context of mixed layer processes. The study describes the materials and methods . To compare the hydrography of the AS and BOB, a unique MLD(Mixed Layer Depth) definition for AS and BOB is essential, for which the 275 CTD profiles were used. A comparison has been made among the various MLD criteria with the actual MLD.
The monthly evolution of MLD, barrier layer thickness and the role of atmospheric forcing on the dynamics of the mixed layer in the AS and BOB were studied. The general hydrography along the west coast of India is described. The upwelling/downwelling, winter cooling processes, in the context of chemical and biological parameters, are also addressed. Finally the general hydrography of the Bay of Bengal is covered. The most striking feature in the hydrography are the signature of an anticyclonic subtropical gyre during spring intermonsoon and a cold core eddy during winter monsoon. The TTS(Typical Tropical Structure) of the euphotic layer was also investigated.
Manoj, Joseph; Dr.Mohanan, P(Cochin University of Science & Technology, October , 2010)
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Abstract:
The thesis is the outcome of the theoretical and experimental investigations on mocrostrip-fed printed strip monopole antenna.Finite ground plane has been effectively utilized to excite a new resonance near the fundamental mode by introducing another extended strip from the ground plane,without affecting compactness.Further size reduction was achieved by carrying out folding analysis on dual strip antenna and a compact folded dual strip antenna has been designed.Design methodologies for both the compact dual band antennas are presented.The proposed antennas can be used for mobile and WLAN applications due to wide bandwidth,moderate gain and omnidirectional radiation coverage.
Description:
Department of
Electronics, Cochin University of Science and Technology.
Sreedevi, E P; Dr.Sankaran, P G(Cochin University Of Science And Technology, April 9, 2010)
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Abstract:
there has been much research
on analyzing various forms of competing risks data. Nevertheless, there are several
occasions in survival studies, where the existing models and methodologies are
inadequate for the analysis competing risks data. ldentifiabilty problem and various
types of and censoring induce more complications in the analysis of competing risks
data than in classical survival analysis. Parametric models are not adequate for the
analysis of competing risks data since the assumptions about the underlying lifetime
distributions may not hold well. Motivated by this, in the present study. we develop
some new inference procedures, which are completely distribution free for the
analysis of competing risks data.
Description:
Department of Statistics, Cochin University of Science and
Technology
Hareesh, G; Dr.Balakrishna, N(Cochin University of Science and Technology, August , 2010)
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Abstract:
The thesis has covered various aspects of modeling and analysis of finite mean time series
with symmetric stable distributed innovations. Time series analysis based on Box and
Jenkins methods are the most popular approaches where the models are linear and errors
are Gaussian. We highlighted the limitations of classical time series analysis tools and
explored some generalized tools and organized the approach parallel to the classical set up.
In the present thesis we mainly studied the estimation and prediction of signal plus noise
model. Here we assumed the signal and noise follow some models with symmetric stable
innovations.We start the thesis with some motivating examples and application areas of alpha stable
time series models. Classical time series analysis and corresponding theories based on finite
variance models are extensively discussed in second chapter. We also surveyed the existing
theories and methods correspond to infinite variance models in the same chapter.
We present a linear filtering method for computing the filter weights assigned to the observation
for estimating unobserved signal under general noisy environment in third chapter.
Here we consider both the signal and the noise as stationary processes with infinite variance
innovations. We derived semi infinite, double infinite and asymmetric signal extraction filters
based on minimum dispersion criteria. Finite length filters based on Kalman-Levy
filters are developed and identified the pattern of the filter weights. Simulation studies show that the proposed methods are competent enough in signal extraction for processes
with infinite variance.Parameter estimation of autoregressive signals observed in a symmetric stable noise
environment is discussed in fourth chapter. Here we used higher order Yule-Walker type
estimation using auto-covariation function and exemplify the methods by simulation and
application to Sea surface temperature data. We increased the number of Yule-Walker
equations and proposed a ordinary least square estimate to the autoregressive parameters.
Singularity problem of the auto-covariation matrix is addressed and derived a modified
version of the Generalized Yule-Walker method using singular value decomposition.In fifth chapter of the thesis we introduced partial covariation function as a tool for stable
time series analysis where covariance or partial covariance is ill defined. Asymptotic results
of the partial auto-covariation is studied and its application in model identification of stable
auto-regressive models are discussed. We generalize the Durbin-Levinson algorithm to
include infinite variance models in terms of partial auto-covariation function and introduce
a new information criteria for consistent order estimation of stable autoregressive model.In chapter six we explore the application of the techniques discussed in the previous
chapter in signal processing. Frequency estimation of sinusoidal signal observed in symmetric
stable noisy environment is discussed in this context. Here we introduced a parametric
spectrum analysis and frequency estimate using power transfer function. Estimate of the
power transfer function is obtained using the modified generalized Yule-Walker approach.
Another important problem in statistical signal processing is to identify the number of
sinusoidal components in an observed signal. We used a modified version of the proposed
information criteria for this purpose.
Description:
Department of Statistics,
Cochin University of Science and Technology
Chandramohan,T; Balachand,A N(Dept. of Physical Oceanography,Faculty of Marine Sciences, 2006)
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Abstract:
It is proposed to study the suspended sediment transport characteristics of river basins of Kerala and to model suspended sediment discharge mechanism for typical micro-watersheds. The Pamba river basin is selected as a representative hydrologic regime for detailed studies of suspended sediment characteristics and its seasonal variation. The applicability of various erosion models would be tested by comparing with the observed event data (by continuous monitoring of rainfall, discharge, and suspended sediment concentration for lower order streams). Empirical, conceptual and physically distributed models were used for making the comparison of performance of the models. Large variations in the discharge and sediment quantities were noticed during a particular year between the river basins investigated and for an individual river basin during the years for which the data was available. In general, the sediment yield pattern follows the seasonal distribution of rainfall, discharge and physiography of the land. This confirms with similar studies made for other Indian rivers. It was observed from this study, that the quantity of sediment transported downstream shows a decreasing trend over the years corresponding to increase in discharge. For sound and sustainable management of coastal zones, it is important to understand the balance between erosion and retention and to quantify the exact amount of the sediments reaching this eco-system. This, of course, necessitates a good length of time series data and more focused research on the behaviour of each river system, both present and past. In this realm of river inputs to ocean system, each of the 41 rivers of Kerala may have dominant yet diversified roles to influence the coastal ecosystem as reflected from this study on the major fraction of transport, namely the suspended sediments
In this modern complex world, stress at work is found to be
increasingly a common feature in day to day life. For the same reason, job
stress is one of the active areas in occupational health and safety research for
over last four decades and is continuing to attract researchers in academia and
industry. Job stress in process industries is of concern due to its influence on
process safety, and worker‘s safety and health. Safety in process (chemical and
nuclear material) industry is of paramount importance, especially in a thickly
populated country like India. Stress at job is the main vector in inducing work
related musculoskeletal disorders which in turn can affect the worker health
and safety in process industries. In view of the above, the process industries
should try to minimize the job stress in workers to ensure a safe and healthy
working climate for the industry and the worker. This research is mainly aimed
at assessing the influence of job stress in inducing work related musculoskeletal
disorders in chemical process industries in India
Description:
School of Engineering
Cochin University of Science and Technology
Anisha,P; Dr.Sankaran, P G(Cochin University of Science and Technology, May 4, 2012)
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Abstract:
This thesis Entitled “modelling and analysis of recurrent event data with multiple causes.Survival data is a term used for describing data that measures the time to occurrence of an event.In survival studies, the time to occurrence of an event is generally referred to as lifetime.Recurrent event data are commonly encountered in longitudinal studies when individuals are followed to observe the repeated occurrences of certain events. In many practical situations, individuals under study are exposed to the failure due to more than one causes and the eventual failure can be attributed to exactly one of these causes.The proposed model was useful in real life situations to study the effect of covariates on recurrences of certain events due to different causes.In Chapter 3, an additive hazards model for gap time distributions of recurrent event data with multiple causes was introduced. The parameter estimation and asymptotic properties were discussed .In Chapter 4, a shared frailty model for the analysis of bivariate competing risks data was presented and the estimation procedures for shared gamma frailty model, without covariates and with covariates, using EM algorithm were discussed.
In Chapter 6, two nonparametric estimators for bivariate survivor function of paired recurrent event data were developed. The asymptotic properties of the estimators were studied. The proposed estimators were applied to a real life data set. Simulation studies were carried out to find the efficiency of the proposed estimators.
Description:
Department of Statistics,
Cochin University of Science and Technology