Sona,Kundukulam O; Manju,Paulson; Aanandan,C K; Mohanan, P; Vasudevan, K(Microwave and Optical Technology Letters, June 5, 2000)
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Abstract:
Experimental studies on a compact dual frequency microstrip
antenna are presented. This antenna configuration provides an
area reduction of 40% compared to a standard rectangular antenna
operating at the same frequency without much degradation of the gain.
The antenna structure can be modified to achieve the desired ratio
between the two resonant frequencies
Binoy,G S; Aanandan,C K; Mohanan, P; Vasudevan, K(International Journal of Electronics, January 12, 2002)
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Abstract:
A new design of' a dual-frequency dual-polarized square microsh'ip antenna fed
along the diagonal, embedded with a square slot having three extended stubs for
frequency tuning, is introduced. The proposed antenna was fabricated using a
standard photolithographic method and the antenna was tested using the HP
3510(:; Vector Network Analyser. The antenna is capable of generating dual
resonant frequencies with mutually perpendicular polarizations and broad
radiation pattern characteristics. Such dual-frequency designs find wide
applications in personal mobile handsets combining GSM and CDS 1800 modes,
and applications in which different frequencies are used for emission and reception
such as personal satellite communications and cellular network systems.
Poulose Jacob,K; Sreela Sasi; Rekha, James K; Shahana, T K; Babita, Jose R(IEEE, May 18, 2008)
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Abstract:
The recent trends envisage multi-standard
architectures as a promising solution for the future wireless
transceivers. The computationally intensive decimation filter
plays an important role in channel selection for multi-mode
systems. An efficient reconfigurable implementation is a key to
achieve low power consumption. To this end, this paper presents
a dual-mode Residue Number System (RNS) based decimation
filter which can be programmed for WCDMA and 802.11a
standards. Decimation is done using multistage, multirate finite
impulse response (FIR) filters. These FIR filters implemented in
RNS domain offers high speed because of its carry free
operation on smaller residues in parallel channels. Also, the FIR
filters exhibit programmability to a selected standard by
reconfiguring the hardware architecture. The total area is
increased only by 33% to include WLANa compared to a single
mode WCDMA transceiver. In each mode, the unused parts of
the overall architecture is powered down and bypassed to attain
power saving. The performance of the proposed decimation
filter in terms of critical path delay and area are tabulated
Description:
Circuits and Systems, 2008. ISCAS 2008. IEEE International Symposium on
Pages
952-955
Sona,Kundukulam O; Manju,Paulson; Aanandan,C K; Mohanan, P(Microwave and Optical Technology Letters, September 20, 2002)
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Abstract:
Experimental and simulated results for a dual-port
dual-polarized microstrip antenna are presented. The antenna excites
two orthogonally polarized resonant frequencies providing an isolation
of -30 dB between the ports. The patch geometry consists of
two circular arcs of different radii with their centers displaced by a
distance. This new design offers an area reduction of -70% coinpared
to it standard rectangular microstrip antenna with a reduction
in gain of 1.7 dB
Parvathi, R; Indic, P; Nampoori, V P N(Elsevier, February 11, 2002)
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Abstract:
Nonlinear time series analysis is employed to study the complex behaviour exhibited by a coupled pair of Rossler systems. Dimensional analysis with emphasis on the topological correlation dimension and the Kolmogorov entropy of the system is carried out in the coupling parameter space. The regime of phase synchronization is identified and the extent of synchronization between the systems constituting the coupled system is quantified by the phase synchronization index. The effect of noise on the coupling between the systems is also investigated. An exhaustive study of the topological, dynamical and synchronization properties of the nonlinear system under consideration in its characteristic parameter space is attempted.
Leena,P; Dr.Babu, C A(Department of Atmospheric Science, 2000)
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Abstract:
The objective of the study is to examine the dynamic and thermodynamic structure and the variations that occur in the surface layer during the pre-monsoon, onset and post-monsoon periods over the Indian region. The variations caused during the occurrence of micro and mesoscale systems, structure and variation in the marine boundary layer over the Indian region is also investigated. The drag coefficient computed indirectly also shows variation during various seasons. The thermodynamic structure of the atmosphere shows variation during the various seasons. The onset monsoon causes lowering of the Lifting Condensation Levels. The outcome of the study is expected to provide a better understanding of the structure and variations in the boundary layer over India, which is useful for many applications especially for numerical modeling studies.
Hamza, Varikoden; Dr.Babu, C A(Department of Atmospheric Science, May , 2006)
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Abstract:
Atmospheric Boundary layer (ABL) is the layer just above the earth surface and is influenced by the surface forcing within a short period of an hour or less. In this thesis, characteristics of the boundary layer over ocean, coastal and inland areas of the atmosphere, especially over the monsoon regime are thoroughly studied. The study of the coastal zone is important due to its high vulnerability mainly due to sea breeze circulation and associated changes in the atmospheric boundary layer. The major scientific problems addressed in this thesis are diurnal and seasonal variation of coastal meteorological properties, the characteristic difference in the ABL during active and weak monsoons, features of ABL over marine environment and the variation of the boundary layer structure over an inland station.
The thesis describes the various features in the ABL associated with the active and weak monsoons and, the surface boundary layer properties associated with the active and weak epochs. The study provides knowledge on MABL and can be used as the estimated values of boundary layer parameters over the marine atmosphere and to know the values and variabilities of the ABL parameters such as surface wind, surface friction, drag coefficient, wind stress and wind stress curl.
Sunoj, S M; Linu, M N(Taylor & Francis, May 2, 2010)
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Abstract:
Recently, cumulative residual entropy (CRE) has been found to be a new measure of information that
parallels Shannon’s entropy (see Rao et al. [Cumulative residual entropy: A new measure of information,
IEEE Trans. Inform. Theory. 50(6) (2004), pp. 1220–1228] and Asadi and Zohrevand [On the dynamic
cumulative residual entropy, J. Stat. Plann. Inference 137 (2007), pp. 1931–1941]). Motivated by this finding,
in this paper, we introduce a generalized measure of it, namely cumulative residual Renyi’s entropy,
and study its properties.We also examine it in relation to some applied problems such as weighted and equilibrium
models. Finally, we extend this measure into the bivariate set-up and prove certain characterizing
relationships to identify different bivariate lifetime models
George,K E; Komalan, C; Kumar, P A S; Varughese, K T; Thomas, S(eXPRESS Polymer Letters, 2007)
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Abstract:
The dynamic mechanical properties such as storage modulus, loss modulus and damping properties of blends of
nylon copolymer (PA6,66) with ethylene propylene diene (EPDM) rubber was investigated with special reference to the
effect of blend ratio and compatibilisation over a temperature range –100°C to 150°C at different frequencies. The effect of
change in the composition of the polymer blends on tanδ was studied to understand the extent of polymer miscibility and
damping characteristics. The loss tangent curve of the blends exhibited two transition peaks, corresponding to the glass
transition temperature (Tg) of individual components indicating incompatibility of the blend systems. The morphology of
the blends has been examined by using scanning electron microscopy. The Arrhenius relationship was used to calculate the
activation energy for the glass transition of the blends. Finally, attempts have been made to compare the experimental data
with theoretical models.
Joseph, P V; Jacob,Chacko(Department of Chemical Oceanography, 2002)
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Abstract:
The proposed study is an attempt to quantify and study the seasonal and spatial variations in the distribution of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb among the various geochemical phases in the surficial sediments of Chitrapuzha river. The study also estimates the concentration of heavy metals in dissolved, particulate and sediments and their variation in seasonal and spatial distribution. Chitrapuzha River originates as a small stream from the upper reaches of high ranges in the eastern boundary of Kerala, passes through the valley and finally joints in the Cochin backwaters. Numerous industrial units located along the banks of the river discharge treated and untreated effluents into the water. These are long standing local complaints about water pollution causing fish mortality and serious damage to agricultural crops resulting in extensive unemployment in the area. The river is thus of considerable social and economic importance.
Sabu,P; Dr.Revichandran,C(Cochin University of Science & Technology, January , 2009)
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Abstract:
The present study
examines the importance of low saline waters and resulting barrier layer
in the dynamics of the ASWP using observational data.The oceanic general circulation models (OGCM) are very useful for
exploring the processes responsible for the ASWP and their variability.
The circulation and thermohaline structure stimulated by an OGCM
changes a lot when the resolution is increased from mesoscale to macro
scale. For a reasonable simulation of the ASWP, we must include the
mesoscale turbulence in numerical models. Especially the SEAS is an
eddy prominent region with a horizontal dimension of 100 to 500 km and
vertical extent of hundred meters. These eddies may have an important
role on the evolution of ASWP, which has not been explored so far.Most of the earlier studies in the SEAS showed that the heat buildup
in the mixed layer during the pre-monsoon (March-May) is primarily
driven by the surface heat flux through the ocean-atmosphere interface,
while the 3-dimensional heat budget of the ML physical processes that are
responsible for the formation of the ASWP are unknown. With this
background the present thesis also examines the relative importance of
mixed layer processes that lead to the formation of warm pool in the
SEAS.
Philip, Thomas; Dr.Meera Bai,M(Cochin University of Science and Technology, May , 1996)
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Abstract:
The following objectives have been formulated for
the study.
To assess the procurement and marketing practices of
Non—Timber Forest Produce by tribes and Tribal
Co-operative Societies and examine the role of
co—operatives in liberating the tribes from the clutches
of private traders.
To study the relative efficiency of marketing channels.
To analyse the inter—difference between tribes and
regions in the collection and marketing of Non—Timber
Forest produce.
To examine the forward linkage of tribal co-operative
societies with the Ayurvedic Medicinal Manufacturing
Units of the state.
To examine the impact of marketing on employment and
income of tribes and
To examine the extent of involvement of tribes in Tribal
Co-operative Societies in policy formulation and
implementation.
Description:
Department of Applied Economics.
Cochin University of Science and Technology
Chitra, R Nayak; Kuriakose, V C(Elsevier, June 4, 2007)
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Abstract:
We investigate the effect of the phase difference of appliedfields on the dynamics of mutually coupledJosephsonjunctions. A phase difference between the appliedfields desynchronizes the system. It is found that though the amplitudes of the output voltage values are uncorrelated, a phase correlation is found to exist for small values of applied phase difference. The dynamics of the system is found to change from chaotic to periodic for certain values of phase difference. We report that by keeping the value of phase difference as π, the system continues to be in periodic motion for a wide range of values of system parameters. This result may find applications in devices like voltage standards, detectors, SQUIDS, etc., where chaos is least desired.
Haseena, V A; Dr.Meera Bai,M(Cochin University of Science and Technology, September 9, 2006)
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Abstract:
This thesis Entitled Dynamics of deforestation and Socio-Economic profile of tribal women flok in kerala -A study of Attappady. The study was based on both primary and secondary data. Primary data
were collected through a sample survey conducted in three panchayaths .The thesis is organized in eight chapters. The first chapter provides the background to the study. Second chapter reviews the literature. Third chapter provides the profile of the study area and general conditions. Fourth chapter
consists of the life cycle structure of the tribal woman. Fifth chapter covers the socio-economic conditions of the tribal women in the study area. Sixth chapter consists of relationship between tribal women and forest and the degradation of the forest. Seventh chapter provides the documentation of the development programmes implemented in Attappady and their importance to the tribals. Last chapter consists of summary and conclusions of the study, suggestions and recommendations of the study.
Description:
Department of Applied Economics, Cochin University of Science and Technology