Pravitha, Ramanand; Nampoori, V P N; Sreenivasan, R(Imperial College Press, 2004)
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Abstract:
n this paper, a time series complexity analysis of dense array electroencephalogram signals is carried out using the recently introduced Sample Entropy (SampEn) measure. This statistic quantifies the regularity in signals recorded from systems that can vary from the purely deterministic to purely stochastic realm. The present analysis is conducted with an objective of gaining insight into complexity variations related to changing brain dynamics for EEG recorded from the three cases of passive, eyes closed condition, a mental arithmetic task and the same mental task carried out after a physical exertion task. It is observed that the statistic is a robust quantifier of complexity suited for short physiological signals such as the EEG and it points to the specific brain regions that exhibit lowered complexity during the mental task state as compared to a passive, relaxed state. In the case of mental tasks carried out before and after the performance of a physical exercise, the statistic can detect the variations brought in by the intermediate fatigue inducing exercise period. This enhances its utility in detecting subtle changes in the brain state that can find wider scope for applications in EEG based brain studies.
Rani, Joseph(Optical Society of America, October 29, 2001)
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Abstract:
A new polymer matrix sensitized with methylene blue for use as an optical recording material is described
here. The characterization is done to determine the optimal recording conditions. These films need no
chemical development and are found to be stable for several months. The matrix has excellent shelf life
and needs an exposure only as short as 20 s. Direct imaging was done on this material.
Biju Kumar, S; Honey, John; Rani, Joseph; Hajian,M; Ligthart, L P; Mathew, K T(Elsevier Science, 2001)
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Dielectric properties of polyaniline at different frequencies were studied. Cavity perturbation technique was employed for the
study. Poly aniline in the powder and pelletised forms were prepared under different environmental conditions. Different samples of
poly aniline exhibit high conductivity. However. the conductivity of samples prepared under different environmental conditions is
found to vary. All the samples in the powder form have high conductivity irrespective of the method of preparation. The high
conductivity at microwave frequency makes it possible to be used for developing microwave components like filters.
Dielectric properties of polyaniline at different frequencies were studied. Cavity perturbation technique was employed for the
study. Poly aniline in the powder and pelletised forms were prepared under different environmental conditions. Different samples of
poly aniline exhibit high conductivity. However, the conductivity of samples prepared under different environmental conditions is
found to vary. All the samples in the powder form have high conductivity irrespective of the method of preparation. The high
conductivity at microwave frequency makes it possible to be used for developing microwave components like filters.
The room temperature AC conductivity σ(ω) of amorphous AsSe samples with various compositions have been measured in the 103 -106 Hz frequency range. The results indicate that ac conductivity is proportional to n with n=0.89±.01 in the 103 –106 Hz frequency range. Consideration of different models for the frequency –dependent conductivity leads to thermally activated hopping as the most likely process
Description:
International Journal of Scientific and Research Publications, Volume 4, Issue 5, May 2014
Daleesha M Viswanathan; Dr. Sumam Mary Idicula(Cochin University of Science and Technology, August 4, 2015)
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Sign language is the primary means of communication for the hard to
hear and speak people around the globe. Sign language emphasizes on visual
possibilities as the participants are unable to hear sound patterns. Sign language
uses different signs, body postures and gestures as opposed to sound patterns
for communication, and evolves like any other spoken language. American
Sign Language (ASL), British sign language (BSL), Arabic sign language
(ArSL), Chinese sign language (CSL) and Indian sign language (ISL) are some
of the widely used sign language systems around the world. There exists
significant variation between sign languages, and due to these inherent
variations, it is not possible to fully adopt a methodology that is found suitable
for all. There are enormous complexities in ISL. Contrary to ASL, ISL
sentences follow Subject-Object-Verb pattern. For example, the relative
positioning of hand on face with respect to nose can convey ‘WOMAN’ or
‘THINK’ in ISL. Such complexities necessitate independent research in ISL.
Sign language recognition involves integration of different categories
of signs. The signs can be mainly categorized into three groups like static hand
gestures, dynamic gestures and facial expression. This research focuses on
these three different channels and work to identify the potential of different
computational methods to address some of the associated complexities with
each channel. These complexities include static gestures with resemblances,
static overlaid gestures, differential movement and directional changes in
dynamic gestures and facial expression changes.
We propose a novel, simple, efficient and distribution-free re-sampling technique for developing prediction intervals for returns and volatilities following ARCH/GARCH models. In particular, our key idea is to employ a Box–Jenkins linear representation of an ARCH/GARCH equation and then to adapt a sieve bootstrap procedure to the nonlinear GARCH framework. Our simulation studies indicate that the new re-sampling method provides sharp and well calibrated prediction intervals for both returns and volatilities while reducing computational costs by up to 100 times, compared to other available re-sampling techniques for ARCH/GARCH models. The proposed procedure is illustrated by an application to Yen/U.S. dollar daily exchange rate data.
Litta, A J; Dr.Sumam Mary,Idicula(Cochin University of Science And Technology, November , 2013)
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Thunderstorm is one of the most spectacular weather phenomena
in the atmosphere. Many parts over the Indian region experience
thunderstorms at higher frequency during pre-monsoon months (March-
May), when the atmosphere is highly unstable because of high
temperatures prevailing at lower levels. Most dominant feature of the
weather during the pre-monsoon season over the eastern Indo-Gangetic
plain and northeast India is the outburst of severe local convective
storms, commonly known as ‘Nor’wester’ or ‘Kalbaishakhi’. The severe
thunderstorms associated with thunder, squall line, lightning and hail
cause extensive losses in agriculture, damage to structure and also loss of
life. The casualty due to lightning associated with thunderstorms in this
region is the highest in the world. The highest numbers of aviation
hazards are reported during occurrence of these thunderstorms. In India,
72% of tornadoes are associated with this thunderstorm.
Description:
Department of Computer Science, Cochin University of Science and Technology
Krishnakumar,S; Dr.Ravindranatha Menon,N(Cochin University of Science and Technology, September , 2009)
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Abstract:
The application of computer vision based quality control has been slowly but steadily gaining importance mainly due to its speed in achieving results and also greatly due to its non- destnictive nature of testing. Besides, in food applications it also does not contribute to contamination. However, computer vision applications in quality control needs the application of an appropriate software for image analysis. Eventhough computer vision based quality control has several advantages, its application has limitations as to the type of work to be done, particularly so in the food industries. Selective applications, however, can be highly advantageous and very accurate.Computer vision based image analysis could be used in morphometric measurements of fish with the same accuracy as the existing conventional method. The method is non-destructive and non-contaminating thus providing anadvantage in seafood processing.The images could be stored in archives and retrieved at anytime to carry out morphometric studies for biologists.Computer vision and subsequent image analysis could be used in measurements of various food products to assess uniformity of size. One product namely cutlet and product ingredients namely coating materials such as bread crumbs and rava were selected for the study. Computer vision based image analysis was used in the measurements of length, width and area of cutlets. Also the width of coating materials like bread crumbs was measured.Computer imaging and subsequent image analysis can be very effectively used in quality evaluations of product ingredients in food processing. Measurement of width of coating materials could establish uniformity of particles or the lack of it. The application of image analysis in bacteriological work was also done
Description:
Dept. of Marine Biology, School of Ocean Science and
Technology, Cochin University of Science & Technology
The median (antimedian) set of a profile π = (u1, . . . , uk) of vertices of a
graphG is the set of vertices x that minimize (maximize) the remoteness i d(x,ui ).
Two algorithms for median graphs G of complexity O(nidim(G)) are designed,
where n is the order and idim(G) the isometric dimension of G. The first algorithm computes median sets of profiles and will be in practice often faster than the other
algorithm which in addition computes antimedian sets and remoteness functions and
works in all partial cubes
Description:
Algorithmica (2010) 57: 207–216
DOI 10.1007/s00453-008-9200-4
Jagathy Raj, V P; Balakrishnan, Menon(IJRFM, September , 2011)
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Abstract:
Automobile Industry in India is influenced by the presence of national and multi-national
manufacturers. The presence of many manufacturers and brands in the state provides many
choices to the customer. The current market for car manufacturers has been transformed from a
monopoly of one or two manufacturers in the seventies to oligopoly of many manufacturers in
the current marketing scenario. The main objective of the research paper is to explore and
conceptualize various parameters and develop a model, which influence the purchase patterns of
passenger cars in the State of Kerala. Thus, the main purpose of this paper is to come up with a
model, which shall facilitate further study on the consumer purchase behaviour patterns of
passenger car owners in the State of Kerala, India. The author intends to undertake further
quantitative analysis to verify and validate the model so developed. The main methods used for
this paper are secondary research on available material, depth interview of car dealers, car
financing agencies and car owners in the city of Cochin, in Kerala State in India.
The depth interviews were conducted with the use of prepared questionnaire for car dealers, car
customers and car financing agencies. The findings resulted in the identification of the
parameters that influence the consumer purchase behaviour of passenger cars and the
formulation of the model, which will be the basis for the further research of the author. The
paper will be of tremendous value to the existing and new car manufacturers both indigenous
and foreign, to formalize and strategies their policies towards an effective marketing strategy, so
as to market their models in the State, which is known for its high literacy, consumerism and
higher educational penetration
Johny,Scaria; Unnikrishnan Nair, N(Department of Statistics,Faculty of Science, 2003)
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Abstract:
The study deals with the distribution theory and applications of concomitants from the Morgenstern family of bivariate distributions.The Morgenstern system of distributions include all cumulative distributions of the form FX,Y(X,Y)=FX(X) FY(Y)[1+α(1-FX(X))(1-FY(Y))], -1≤α≤1.The system provides a very general expression of a bivariate distributions from which members can be derived by substituting expressions of any desired set of marginal distributions.It is a brief description of the basic distribution theory and a quick review of the existing literature.The Morgenstern family considered in the present study provides a very general expression of a bivariate distribution from which several members can be derived by substituting expressions of any desired set of marginal distributions.Order statistics play a very important role in statistical theory and practice and accordingly a remarkably large body of literature has been devoted to its study.It helps to develop special methods of statistical inference,which are valid with respect to a broad class of distributions.The present study deals with the general distribution theory of Mk, [r: m] and Mk, [r: m] from the Morgenstern family of distributions and discuss some applications in inference, estimation of the parameter of the marginal variable Y in the Morgestern type uniform distributions.
Conducting polymers are excellent microwave absorbers
and they show technological advantage when compared
with inorganic electromagnetic absorbing materials,
being light weight , easily processable, and the ability
of changing the electromagnetic properties with nature
and amount of dopants, synthesis conditions, etc. In this
paper we report the synthesis, dielectric properties, and
expected application of conducting composites based
on polyaniline (PAN). Cyclohexanone soluble conducting
PAN composites of microwave conductivity 12.5 S/m
was synthesized by the in situ polymerization of aniline
in the presence of emulsion grade polyvinyl chloride. The
dielectric properties of the composites, especially the
dielectric loss, conductivity, dielectric heating coefficient
, absorption coefficient, and penetration depth,
were studied using a HP8510 vector network analyzer.
The microwave absorption of the composites were studied
at different frequency bands i.e, S, C, and X bands
(2-12 GHz). The absorption coefficient was found to be
higher than 200 m -' and it can be used for making microwave
absorbers in space applications