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Search Results: 1 - 10 of 150051 matches for " Vidya H. Kopanar "
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Elliptical Iris Detection using Morphological Operations
Prakash J. Kulkarni,Vidya H. Kopanar
International Journal of Computer Science and Mobile Computing , 2013,
Abstract: This paper presents a method to detect an iris to operate in 3D coordinate system. As perprojective geometry, circle in 3D is projected as an ellipse in 2D. Hence, iris is detected as an ellipse insteadof a circle. Morphological operations of light computations are used to detect an iris, which reduces time todetect an iris. Eye images with high resolution provide more number of pixels giving accuracy. Such detectedellipse can be further used to map to a circle in 3D using calibrated camera.
Numerical Analysis of Stresses on Layer-by-Layer Basis in FML Composite Cylinder Subjected to External Hydrostatic Loading  [PDF]
B. G. Sumana, H. N. Vidya Sagar, K. V. Sharma, M. Krishna
Materials Sciences and Applications (MSA) , 2015, DOI: 10.4236/msa.2015.66052
Abstract: The aim of the research work was to numerically investigate the residual stresses induced between the layers of fiber metal laminate (FML) cylinder (glass/epoxy reinforced aluminum laminates) under buckling hydrostatic loading. For the analysis of buckling behavior of FML cylinders, various fiber orientations such as 0/90°, 60/30°, ±45° and ±55° and different FRP thickness of 1, 2, and 3 mm were considered. The aluminum cylinder of inner diameter 80 mm, length 800 mm and wall thickness 1 mm was modeled with SHELL281 element type and a total of 1033 elements were used for computing the induced residual stresses between the layers. The results show that magnitude of residual stresses between the layers decreased along the thickness from outer layer towards the inner layer in sine wave form. The maximum residual Von-Mises stress was at inner aluminum layer while the maximum residual radial stress was at the outermost layer of FML cylinder due to the inward pressure. Among all types of FML cylinder 0/90° fiber oriented FML cylinder exhibited the least radial stress and a maximum Von-Mises stress along the FRP thickness.
Understanding H-defect complexes in ZnO
R. Vidya,P. Ravindran,H. Fjellv?g
Physics , 2013,
Abstract: From state-of-the-art density-functional calculations using hybrid functionals we show that, persistent $n$-type conductivity in ZnO is due to defect complexes formed between H with intrinsic and extrinsic defects. H exhibits cationic, anionic, and electrically-inactive character on interacting with defects in ZnO. The electrically-inactive molecular hydrogen can contribute to $n$-type conductivity in ZnO by activating deep donor levels into shallow levels. By calculating local vibrational mode frequencies, we have identified origins of many H-related Raman and infra-red frequencies and thus confirmed the amphoteric behavior of H.
Bandwidth Optimization in 802.15.4 Networks through Evolutionary Slot Assignment  [PDF]
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2009, DOI: 10.4236/ijcns.2009.26057
Abstract: Traditional Wireless Sensor Networks (WSNs) based on carrier sense methods for channel access suffer from reduced bandwidth utilization, increase energy consumptions and latency problems in networks with high traffic. In this work, a novel Evolutionary Slot Assignment (ESA) algorithm has been developed to in-crease the throughput of large wireless mesh networks with no centralized controller. In the presented scheme, the sensor nodes self-adapt to the traffic patterns of the network by selecting transmission slots us-ing evolutionary learning methods. Each sensor node evolves an independent transmission schedule. Unlike traditional evolutionary methods, fitness evaluation of every node impacts fitness of every other sensor node in the network. The ESA algorithm has been simulated using Network Simulator-2 and compared with the IEEE 802.15.4 CSMA-CA, a Static Slot Assignment (SSA) and a Random Slot Assignment schemes (RSA). Results show a remarkable improvement in the network throughput using the proposed ESA method as op-posed to other compared methods.
Use of Solid-Supported Reagents towards Synthesis of 2-Arylbenzoxazole, 3, 5-Diarylisoxazole and 1, 3, 5-Triarylpyrazole  [PDF]
Sneha Naik, Vidya Desai
Green and Sustainable Chemistry (GSC) , 2013, DOI: 10.4236/gsc.2013.31001

Herein we report a convenient and efficient synthesis of 2-Arylbenzoxazole from the Schiff’s bases of 2-Aminophenol, 3, 5-Diarylisoxazole from α, β-unsaturated ketoxime and 1,3,5-Triarylpyrazole from 2-pyrazoline and N-Arylhydrazone by using milder, less toxic and less expensive-NBS-SiO2, KMnO4-Al2O3, PCC-SiO2 and ACC-Al2O3 as solid-supported oxidizing agents at room temperature. Within the framework of Green Chemistry, the use of solid supported reagents has many advantages such as 1) they are easy to remove from reactions by filtration 2) excess reagents can be used to drive the reaction without introducing any difficulties in purification 3) such solid-supported reagents react differently, mostly more selectively, than their unbound counterparts and 4) toxic, noxious and explosive chemicals are handled more safely when contained on solid support.

Measuring Decentralisation in Reforms Era: A Case of Kalyan-Dombivli, India  [PDF]
Vidya Sagar Pancholi
Current Urban Studies (CUS) , 2014, DOI: 10.4236/cus.2014.22012

Since last couple of decades, there is an emerging trend of decentralisation and India is no exception to such a trend. Studies that measure decentralisation in India, however, are mostly comparative and target a limited set of parameters. This paper, attempts at a comprehensive examination of a case of Kalyan-Dombivli (KD), a fringe subcity to Mumbai. The analysis brings out that over the past seven years (since the beginning of the centrally sponsored urban renewal program), even though the local body in KD had higher resources for local development, its functional authority, fiscal autonomy, and accountability has been significantly re-centralised towards higher level governments. The case analysis brings out key lessons in terms of need for focusing on the empowerment (functional and fiscal) of local bodies and creating accountability structures that are effective and responsive to the local citizenry.

Removal of Interferences from Partial Discharge Pulses using Wavelet Transform
Vidya H.A,Bindia Tyagi,V Krishnan,K. Mallikarjunappa
Abstract: It is essential to detect partial discharge (PD) as a symptom of insulation breakdown in high voltage (HV) applications. However accuracy of such measurement is often degraded due to the existence of noise in the signal. Wavelet Transform (WT) seems to be more suitable than traditional Fourier Transform in analyzing signals with interesting transient information such as partial discharge (PD) signals. In this paper a WT method with soft thresholding is used for signal denoising. PD signals and corona obtained from actual measurements with different voltage magnitudes are processed. Processed signals show the better result.
Spin, charge and orbital ordering in ferrimagnetic insulator YBaMn$_2$O$_5$
R. Vidya,P. Ravindran,A. Kjekshus,H. Fjellv?g
Physics , 2001, DOI: 10.1103/PhysRevB.65.144422
Abstract: The oxygen-deficient (double) perovskite YBaMn$_2$O$_5$, containing corner-linked MnO$_5$ square pyramids, is found to exhibit ferrimagnetic ordering in its ground state. In the present work we report generalized-gradient-corrected, relativistic first-principles full-potential density-functional calculations performed on YBaMn$_2$O$_5$ in the nonmagnetic, ferromagnetic and ferrimagnetic states. The charge, orbital and spin orderings are explained with site-, angular momentum- and orbital-projected density of states, charge-density plots, electronic structure and total energy studies. YBaMn$_2$O$_5$ is found to stabilize in a G-type ferrimagnetic state in accordance with experimental results. The experimentally observed insulating behavior appears only when we include ferrimagnetic ordering in our calculation. We observed significant optical anisotropy in this material originating from the combined effect of ferrimagnetic ordering and crystal field splitting. In order to gain knowledge about the presence of different valence states for Mn in YBaMn$_2$O$_5$ we have calculated $K$-edge x-ray absorption near-edge spectra for the Mn and O atoms. The presence of the different valence states for Mn is clearly established from the x-ray absorption near-edge spectra, hyperfine field parameters and the magnetic properties study. Among the experimentally proposed structures, the recently reported description based on $P$4/$nmm$ is found to represent the stable structure.
Violation of the Minimum H-H Separation "Rule" for Metal Hydrides
P. Ravindran,P. Vajeeston,R. Vidya,A. Kjekshus,H. Fjellvaag
Physics , 2002, DOI: 10.1103/PhysRevLett.89.106403
Abstract: Using gradient-corrected, all-electron, full-potential, density-functional calculations, including structural relaxations, it is found that the metal hydrides $RT$InH$_{1.333}$ (R = La, Ce, Pr, or Nd; T = Ni, Pd, or Pt) possess unusually short H-H separations. The most extreme value (1.454 {\AA}) ever obtained for metal hydrides occurs for LaPtInH$_{1.333}$. This finding violates the empirical rule for metal hydrides, which states that the minimum H-H separation is 2 {\AA}. Electronic structure, charge density, charge transfer, and electron localization function analyses on $RT$InH$_{1.333}$ show dominant metallic bonding with a non-negligible ionic component between T and H, the H-H interaction beingweakly metallic. The paired, localized, and bosonic nature of the electron distribution at the H siteare polarized towards La and In which reduces the repulsive interaction between negatively charged H atoms. This could explain the unusually short H-H separation in these materials. Also, R-R interactions contribute to shielding of the repulsive interactions between the H atoms.
Seasonal variation in the incidence of preeclampsia and eclampsia in tropical climatic conditions
Vidya Subramaniam
BMC Women's Health , 2007, DOI: 10.1186/1472-6874-7-18
Abstract: We retrospectively analysed data from a large maternity centre in Mumbai, India over a period of 36 months from March 1993 to February 1996, recording the incidence of preeclampsia and eclampsia. Meteorological data was acquired from the regional meteorological centre recording the monthly average temperature, humidity, barometric pressure and rainfall during the study period. Study period was then divided into two climate conditions: monsoon season (June to August) and dry season September to May. The incidence of preeclampsia and eclampsia and the meteorological differences between the two seasons were compared.Over a 36-month period, a total of 29562 deliveries were recorded, of which 1238 patients developed preeclampsia (4.18%) and 34 developed eclampsia (0.11%). The incidence of preeclampsia did not differ between the monsoon and the dry season (4.3% vs. 4.15%, p = 0.5). The incidence of eclampsia was significantly higher in the monsoon (0.2% vs. 0.08%, p = 0.01). The monsoon was significantly cooler (median maximum temperature 30.7°C vs. 32.3°C, p = 0.01), more humid (median relative humidity 85% vs. 70%, p = 0.0008), and received higher rainfall (median 504.9 mm vs. 0.3 mm, p = 0.0002) than the rest of the year. The median barometric pressure (1005 mb) during the monsoon season was significantly lower than the rest of the year (1012 mb, p < 0.0001).In the tropical climate of Mumbai, the incidence of eclampsia is significantly higher in monsoon, when the weather is cooler and humid with a lower barometric pressure than the rest of the year. This effect is not seen with preeclampsia. This strengthens the association of low temperature and high humidity with triggering of eclampsia.The aetiology of preeclampsia and eclampsia is not fully understood. Previous studies have shown a variable association of preeclampsia and eclampsia with the changing weather patterns of different seasons. These association studies often compared the incidence of preeclampsia and ecl
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