Renjith, V R; Dr.Madhu, G(Cochin University of Science & Technology, July , 2010)
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Abstract:
The hazards associated with major accident hazard (MAH) industries
are fire, explosion and toxic gas releases. Of these, toxic gas release is the worst
as it has the potential to cause extensive fatalities. Qualitative and quantitative
hazard analyses are essential for the identitication and quantification of the
hazards associated with chemical industries. This research work presents the
results of a consequence analysis carried out to assess the damage potential of
the hazardous material storages in an industrial area of central Kerala, India. A
survey carried out in the major accident hazard (MAH) units in the industrial
belt revealed that the major hazardous chemicals stored by the various industrial
units are ammonia, chlorine, benzene, naphtha, cyclohexane, cyclohexanone
and LPG. The damage potential of the above chemicals is assessed using
consequence modelling. Modelling of pool fires for naphtha, cyclohexane,
cyclohexanone, benzene and ammonia are carried out using TNO model. Vapor
cloud explosion (VCE) modelling of LPG, cyclohexane and benzene are carried
out using TNT equivalent model. Boiling liquid expanding vapor explosion
(BLEVE) modelling of LPG is also carried out. Dispersion modelling of toxic
chemicals like chlorine, ammonia and benzene is carried out using the ALOHA
air quality model. Threat zones for different hazardous storages are estimated
based on the consequence modelling. The distance covered by the threat zone
was found to be maximum for chlorine release from a chlor-alkali industry
located in the area. The results of consequence modelling are useful for the
estimation of individual risk and societal risk in the above industrial area.Vulnerability assessment is carried out using probit functions for toxic,
thermal and pressure loads. Individual and societal risks are also estimated at
different locations. Mapping of threat zones due to different incident outcome
cases from different MAH industries is done with the help of Are GIS.Fault Tree Analysis (FTA) is an established technique for hazard
evaluation. This technique has the advantage of being both qualitative and
quantitative, if the probabilities and frequencies of the basic events are known.
However it is often difficult to estimate precisely the failure probability of the
components due to insufficient data or vague characteristics of the basic event.
It has been reported that availability of the failure probability data pertaining to
local conditions is surprisingly limited in India. This thesis outlines the
generation of failure probability values of the basic events that lead to the
release of chlorine from the storage and filling facility of a major chlor-alkali
industry located in the area using expert elicitation and proven fuzzy logic.
Sensitivity analysis has been done to evaluate the percentage contribution of
each basic event that could lead to chlorine release. Two dimensional fuzzy
fault tree analysis (TDFFTA) has been proposed for balancing the hesitation
factor invo1ved in expert elicitation .
Description:
Division of Safety and Fire Engineering,
School of Engineering,
Cochin University of Science and Technology
Abdul, Salam V H; Dr.Babu,Jose T(Cochin University of Science and Technology, November , 1999)
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Abstract:
Chapter 1 presents a brief note on the state at which the construction industry
stands at present, bringing into focus the significance of the critical study. Relevance
of the study, area of investigation and objectives of the study are outlined in this
chapter. The 2nd chapter presents a review of the literature on the relevant areas.
In the third chapter an analysis on time and cost overrun in construction
highlighting the major factors responsible for it has been done. A couple of case
studies to estimate loss to the nation on account of delay in construction have been
presented in the chapter. The need for an appropriate estimate and a competent
contractor has been emphasised for improving effectiveness in the project
implementation. Certain useful equations and thoughts have been formulated on this
area in this chapter that can be followed in State PWD and other Govt. organisations.
Case studies on project implementation of major projects undertaken by
Government sponsored/supported organizations in Kerala have been dealt with in
Chapter 4. A detailed description of the project of Kerala Legislature Complex with a
critical analysis has been given in this chapter. A detailed account of the investigations carried out on the construction of International Stadium, a sports project
of Greater Cochin Development Authority is included here. The project details of
Cochin International Airport at Nedumbassery, its promoters and contractors are also
discussed in Chapter 4.
Various aspects of implementation which led the above projects successful have
been discussed in chapter 5. The data collected were analysed through discussion and
perceptions to arrive at certain conclusions. The emergence of front-loaded contract
and its impact on economics of the project execution are dealt with in this chapter.
Analysis of delays in respect of the various project narrated in chapter 3 has been done
here. The root causes of the project time and overrun and its remedial measures are
also enlisted in this chapter.
Study of cost and time overrun of any construction project IS a part of
construction management. Under the present environment of heavy investment on
construction activities in India, the consequences of mismanagement many a time lead
to excessive expenditure which are not be avoidable. Cost consciousness, therefore has
to be keener than ever before. Optimization in investment can be achieved by
improved dynamism in construction management. The successful completion of
coristruction projects within the specified programme, optimizing three major attributes
of the process - quality, schedule and costs - has become the most valuable and
challenging task for the engineer - managers to perform. So, the various aspects of
construction management such as cost control, schedule control, quality assurance,
management techniques etc. have also been discussed in this fifth chapter.
Chapter 6 summarises the conclusions drawn from the above criticalr1 of rhajor
construction projects in Kerala.
Description:
School of Engineering,Cochin University of Science and Technology
Saira Joseph; Dr. Binu Paul(Cochin University of Science and Technology, November 20, 2016)
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Abstract:
Over the past decade, there is a great demand for permission to transmit large bandwidth
concurrent with existing narrowband signals. In 2002, the federal communications
commission (FCC) decided to permit use of ultrawideband (UWB) systems.
UWB systems are unique in their large instantaneous bandwidth and potential for lowcost
digital design that enables a single system to operate in different modes as a
communication device, radar etc. UWB systems aim at covering the frequency band of
3.1-10.6 GHz defined by the FCC. The addition of more and more features in each new
generation communication system demands universal antennas suitable for operation in
multiple bands. In this regard, designing a multiband antenna which also covers the
UWB range without deteriorating the UWB performance is of great interest. Also, a
significant issue in communication systems is to miniaturize the antenna size while
providing good performance over the operation bands.
The thesis presents three different designs of CPW-fed multiband antennas. The first
design uses a fractal concept to achieve multiband operation. In the second and third
designs, a slotted circular monopole and a spiral monopole are used respectively for
multiband operation with UWB applications. For both these cases, variations from the
basic antenna geometry are also proposed in which the frequency of operation is
lowered without increase in overall antenna size. Design guidelines are developed for
all antennas to facilitate design on substrates of different permittivity and thickness. The
antennas are analyzed in both frequency and time domain for complete characterization
Raphika, P. M.; Dr. Abdulla P.(Cochin University of Science and Technology, May 3, 2016)
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Abstract:
Filters are one of the essential components in the RF and wireless
communication systems. Small sized planar lowpass filters with good electrical
characteristics along with low cost, light weight and ease of fabrication are highly
desirable for the front end of modern communication systems to suppress harmonics
and spurious signals. Design of compact lowpass filters with improved performance
and diverse specifications for numerous applications is a huge challenge.
In this thesis, high performance planar compact lowpass filters using multiple
patch resonators on high impedance transmission line are developed. Design techniques
of different types of patch resonators and their modifications to enhance the
performance of the filters are presented.Patch resonators are designed by using high impedance short circuited stubs
and low impedance open circuited patches. In the first stage of filter realization,
compact lowpass filter having sharp roll-off using triangular and funnel patch
resonators is presented. The structure is modified further to enhance the relative
stopband bandwidth of the filter. In the third stage, another resonator has been
introduced near the feed line to achieve sharp roll-off for the same cutoff frequency,
stopband bandwidth and suppression level. To obtain compactness, high suppression
level and wide stopband in filter design, low thickness substrate is tested and proved in
the fourth stage.
Realizations of planar compact lowpass filter with very sharp roll-off near the
cutoff frequency have been presented using stepped impedance polygonal patch
resonators. By increasing the patch size and number of resonators, the stopband
bandwidth and suppression level have to be enhanced to a great extent. Enhancement
of performance characteristics of lowpass filter design is continually being extended.
By using high value capacitance patch, the stopband suppression level of the filter with
sharp roll-off rate is achieved. Elliptic function lowpass filter with ultra-sharp roll-off is
also developed using elliptic shaped patch resonators.
Throughout the study, low cost substrate having permittivity 4.4 is used for the
filter design. All the designed filters have been fabricated and predicted results are
validated by the measurements.
Baby Paul; Dr. P. Mythili(Cochin University of Science and Technology, October 8, 2015)
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Abstract:
Electrocardiogram gives the information regarding the health of
the patients by monitoring the bioelectric potentials generated by the
sinoatrial node in the heart. These signals can be collected by using
electrodes suitably placed on the body of a patient. The normal human
ECG lie in the frequency range of 0.05-100 Hz and the most useful
information is contained in the range of 0.5-45 Hz. Even though a large
amount of work has already been done in the field of ECG classification,
no classification system has made an attempt in identifying the isolated
abnormalities which pose a silent threat to patients.
An adaptive filtering technique for denoising the ECG which is
based on Genetic Algorithm (GA) tuned Sign-Data Least Mean Square
(SD-LMS) algorithm is proposed. This algorithm gave an average
signal to noise ratio improvement of 10.75 dB for baseline wander and
24.26 dB for power line interference. It is seen that the step size ‘μ’
optimized with GA helps in obtaining better SNR value without causing
any damage to the information content in the ECG.
A new wavelet for automatic classification of arrhythmias
from electrocardiogram is proposed. This new wavelet is formed as a
sum of shifted Gaussians so that it resembles a normal ECG. This shape
has been chosen with the aim of extracting maximum information from
the ECG under analysis. The classification performance was studied
using the most commonly used database, the MIT-BIH Arrhythmia
database. The shifted and summed Gaussian wavelet was then
optimized using GA. The optimum wavelet for classification was
obtained after several runs of the GA algorithm. The ECG class
labeling was done according to the Association for the Advancement of
Medical Instrumentation (AAMI). The wavelet scales corresponding to
the different frequency levels giving maximum classification
performance were identified by selecting finer scales. Probabilistic
Neural Network classifier was used for classification purpose. The
proposed classification system offered better results than that reported
in literature by giving an overall sensitivity of 97.01% for Normal beats,
75.20% for Supraventricular beats and 93.06% for Ventricular beats.
As mentioned above this technique could exclusively identify some of
the isolated abnormalities present in the patient records.
Hari, V S; Dr. Jagathy Raj, V P; Dr.Gopikakumari, R(Cochin University of Science And Technology, June , 2013)
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Abstract:
The basic concepts of digital signal processing are taught to the students
in engineering and science. The focus of the course is on linear,
time invariant systems. The question as to what happens when the
system is governed by a quadratic or cubic equation remains unanswered
in the vast majority of literature on signal processing. Light has
been shed on this problem when John V Mathews and Giovanni L Sicuranza
published the book Polynomial Signal Processing. This book
opened up an unseen vista of polynomial systems for signal and image
processing. The book presented the theory and implementations
of both adaptive and non-adaptive FIR and IIR quadratic systems
which offer improved performance than conventional linear systems.
The theory of quadratic systems presents a pristine and virgin area of
research that offers computationally intensive work. Once the area of
research is selected, the next issue is the choice of the software tool to
carry out the work. Conventional languages like C and C++ are easily
eliminated as they are not interpreted and lack good quality plotting
libraries. MATLAB is proved to be very slow and so do SCILAB and
Octave. The search for a language for scientific computing that was
as fast as C, but with a good quality plotting library, ended up in
Python, a distant relative of LISP. It proved to be ideal for scientific
computing. An account of the use of Python, its scientific computing
package scipy and the plotting library pylab is given in the appendix Initially, work is focused on designing predictors that exploit the polynomial
nonlinearities inherent in speech generation mechanisms. Soon,
the work got diverted into medical image processing which offered
more potential to exploit by the use of quadratic methods. The major
focus in this area is on quadratic edge detection methods for retinal
images and fingerprints as well as de-noising raw MRI signals
Description:
School of Engineering
Cochin University of Science and Technology
Babita Roslind, Jose; Dr.Mythili, P(Cochin University of Science & Technology, January , 2010)
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Abstract:
Analog-to digital Converters (ADC) have an important impact on the overall performance of signal processing system. This research is to explore efficient techniques for the design of sigma-delta ADC,specially for multi-standard wireless tranceivers. In particular, the aim is to develop novel models and algorithms to address this problem and to implement software tools which are avle to assist the designer's decisions in the system-level exploration phase. To this end, this thesis presents a framework of techniques to design sigma-delta analog to digital converters.A2-2-2 reconfigurable sigma-delta modulator is proposed which can meet the design specifications of the three wireless communication standards namely GSM,WCDMA and WLAN. A sigma-delta modulator design tool is developed using the Graphical User Interface Development Environment (GUIDE) In MATLAB.Genetic Algorithm(GA) based search method is introduced to find the optimum value of the scaling coefficients and to maximize the dynamic range in a sigma-delta modulator.
Description:
School of Engineering, Cochin University of Science and Technology