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Search Results: 1 - 10 of 21128 matches for " Prabhat Kumar Vishwakarma "
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Optimizing And Analysing The Effectiveness Of Security Hardening Measures Using Various Optimization Techniques As Well As Network Management Models Giving Special Emphasis To Attack Tree Model
Prabhat Kumar Vishwakarma
International Journal of Network Security & Its Applications , 2011,
Abstract: To cope up the network security measures with the financial restrictions in the corporate world is still a challenge. At global scenario the tradeoff between the protection of IT infrastructure and the financial boundation for any organization using IT as valuable resource is quite essential. Every organization has different security needs and different budgets for coping with that therefore whether it has to look as single objective or as multiple objectives with fault tolerant feature is a critical issue. In the present paper an attempt has been taken to optimize and analyze the effectiveness of security hardening measures considering attack tree model as base. In short we can say that the main attention in the paper is-to rectify, to describe the notations of the attack tree model and to suggest a model which may be able to quantitatively specify the possible threats as well as cost of the security control while implementing the security hardening measures.
Aperture Coupled Microstrip Antenna for Dual-Band  [PDF]
Rajesh Kumar Vishwakarma, Sanjay Tiwari
Wireless Engineering and Technology (WET) , 2011, DOI: 10.4236/wet.2011.22013
Abstract: This paper presents air gap aperture coupled microstrip antenna for dual-band operation over the frequency range of (2.9 to 6.0 GHz). This antenna differs from any other microstrip antenna with their feeding structure of the radiating patch element. Input signal couples to the radiating patch trough the aperture that exists on the ground plane of microstrip feed line. The dual-band achieved by variation of air gap [2 mm to 6 mm] between single patch antenna and aper-ture coupled microstrip antenna. The main advantage of this type antenna is increased the bandwidth of the antenna as compared to a single layered patch antenna. The two resonant frequencies can vary over a wide frequency range and the input impedance is easily matched for both frequencies. The obtain ratios of resonance frequencies are variable from 2.1 GHz to 1.1 GHz with increasing the air gap between single patch and aperture coupled microstrip antenna. The measured return loss [–14 dB] exhibits an impedance bandwidth of 35%. The input impedance and VSWR return loss have been measured with the help of Network analyzer.
Detection and analysis of the effects of heat stress on EEG using wavelet transform ——EEG analysis under heat stress  [PDF]
Prabhat Kumar Upadhyay, Rakesh Kumar Sinha, Bhuwan Mohan Karan
Journal of Biomedical Science and Engineering (JBiSE) , 2010, DOI: 10.4236/jbise.2010.34056
Abstract: Continuous wavelet transform (CWT) method has been applied to capture localized time-frequency information of rat electroencephalogram (EEG) in different vigilance states and analyze alterations in transients during awake, slow wave sleep (SWS), and rapid eye movement (REM) sleep stages due to exposure to high environmental heat. Rats were divided in three group (i) acute heat stress-subjected to a single exposure for four hours in the Biological Oxygen Demand (BOD) incubator at 38?C; (ii) chronic heat stress-exposed for 21 days daily for one hour in the incubator at 38?C, and (iii) handling control groups. After two hours long EEG recordings from young healthy rats, EEG data representing three sleep states was visually selected and further subdivided into 2 seconds long epoch. Powers of wavelet spectra corresponding to delta, theta, alpha, and beta bands at all scales and locations were computed and variation in their states investigated. The wavelet analysis of EEG signals following exposure to high environmental heat revealed that powers of subband frequencies vary with time unlike Fourier technique. Changes in higher frequency components (beta) were significant in all sleep-wake states following both acute and chronic heat stress conditions. Percentage power of different components of the four bands was always found to be varying at different intervals of time in the same signal of analysis.
Predicting heat-stressed EEG spectra by self-organising feature map and learning vector quantizers——SOFM and LVQ based stress prediction  [PDF]
Prabhat Kumar Upadhyay, Rakesh Kumar Sinha, Bhuwan Mohan Karan
Journal of Biomedical Science and Engineering (JBiSE) , 2010, DOI: 10.4236/jbise.2010.35074
Abstract: Self-Organising Feature Map (SOFM) along with learning vector quantizers (LVQ) have been designed to identify the alterations in brain electrical potentials due to exposure to high environmental heat in rats. Three groups of rats were considered—acute heat stressed, chronic heat stressed and control groups. After long EEG recordings following heat exposure, EEG data representing three different vigilance states such as slow wave sleep (SWS), rapid eye movement (REM) sleep and AWAKE were visually selected and further subdivided into 2 seconds long epoch. In order to evaluate the performance of artificial neural network (ANN) in recognizing chronic and acute effects of heat stress with respect to the control subjects, unsupervised learning algorithm was applied on EEG data. Mean performance of SOFM with quadratic taper function was found to be better (chronic-92.6%, acute-93.2%) over the other two tapers. The effect of LVQ after the initial SOFM training seems explicit giving rise to considerable improvements in performance in terms of selectivity and sensitivity. The percentage increase in selectivity with uniform taper function is maximum for chronic and its control group (4.01%) and minimum for acute group (1.29%) whereas, with Gaussian it is almost identical (chronic-2.57%, acute-2.03%, control- 2.33%). Quadratic taper function gives rise to an increase of 2.41% for chronic, 1.96% for acute and 2.91% for control patterns.
Modeling of Discharge Distribution in Bend of Ganga River at Varanasi  [PDF]
Manvendra Singh Chauhan, Prabhat Kumar Singh Dikshit, Shyam Bihari Dwivedi
Computational Water, Energy, and Environmental Engineering (CWEEE) , 2015, DOI: 10.4236/cweee.2015.43004
Abstract: Dynamics of river behavior plays a great role in meandering, sediment transporting, scouring, etc. of river at bend, which solely depends on hydraulics properties such as horizontal and vertical stress, spatial and temporal variation of discharge. Therefore understanding of discharge distribution of river Ganga is essential to apprehend the behavior of river cross section at bend particularly. The measurement of discharge is not very simple as there is no instrument that can measure the discharge directly, but velocity measurement at a section can be made. Velocity distribution at different cross sections at a time is also not easy with single measurement with the help of any instrument and method, so it required repetitions of the measurement. Velocity near the end of bank, top and bottom layer of natural streams is difficult to be measured, yet velocity distribution at these regions plays important role in characterizing the behavior of river. This paper deals with the new advanced discharge measurement technique and measured discharge data has been used for modelling at river bend. To carry out the distribution of discharge and velocity with depth in river Ganga, the length of river in study area was distributed into 14 different cross sections, M-1 to M-14, measured downstream to upstream and the measurement was done by using of ADCP (Acoustic Doppler Current Profiler). At each cross section, profiles were measured independently by an ADCP and data acquired from ADCP were further used for the regression modeling. A multiple linear regression model was developed, which showed a high correlation among the discharge, depth and velocity parameters with the root mean square error (R2) value of 0.8624.
Aperture coupled stacked patch antenna for dual band
Rajesh Kumar Vishwakarma,Sanjay Tiwari
International Journal of Electronics and Computer Science Engineering , 2012,
Abstract: -Microstrip antennas (MAS) are very useful antenna where low profile antennas are required. They are most popular due to their small size, low cost, light weight. The first aperture coupled microstrip antenna was introduced in 1985 by D M Pozar. Aperture coupled antenna is a particular antenna with high gain and wide bandwidth. This paper presents aperture coupled stacked patch antenna using air gap variation. The variation of air gap [2mm to 6mm] has been done between single patch antenna and an aperture coupled antenna. The main advantage of this antenna to increase the band width of the antenna as compared with single layered patch antenna. The resonant frequencies changes with air gap variations. The feed can be done either a conventional coaxial probe or through a coupling aperture in the ground plane as we done. This antenna works well in the frequency range (2.9 GHz to 6.0 GHz). The measured return loss exhibit an impedance bandwidth of 35%.The input impedance and VSWR return loss have been measured with the help of Network analyzer. [Agilent E8363B A.04.06] From the measured result it is found that the value of VSWR corresponding lower resonance frequencies increases from 14 to 2.2 with increasing air gap variation where as at the upper resonance frequencies is also increased from 1.8 to 2.3.
Color Image Enhancement Techniques: A Critical Review
Anish Kumar Vishwakarma,Agya Mishra
Indian Journal of Computer Science and Engineering , 2012,
Abstract: Image enhancement is one of the key issues in high quality pictures such as digital camera and HDTV. Since Image clarity is very easily affected by lighting, weather, or equipment that has been used to capture the image. These conditions lead to image may suffer from loss of information. As a result, many techniques have developed known as image Enhancement techniques to recover the information in an image. This paper presents a literature review on some of the image Enhancement techniques for color image enhancement like, Contrast Stretching, Histogram Equalization and its improvement versions, Homomorphic Filtering, Retinex, and Wavelet Multiscale Transform. Comparison of all the techniques concludes the better approach for its future research.
A review of Support Vector Clustering with different Kernel function for Reduction of noise and outlier for Large Database
Deepak Kumar Vishwakarma, Anurag Jain
International Journal of Advanced Computer Research , 2012,
Abstract: For a long decade clustering faced a problem of noise and outliers. Support Vector Clustering is one of the techniques in pattern recognition. Support Vector Clustering is Kernel-Based Clustering. Division of patterns, data items, and feature vectors into groups (clusters) is a complicated task since clustering does not assume any prior knowledge, which are the clusters to be searched for. Noise and outlier reduces the mapping probability of sphere in support vector clustering. Support vector clustering is inspired clustering technique form the support vector Machine. The prediction and accuracy of support vector clustering depends upon kernel function of hyper plane. Kernel function is a heart of classifier. In this paper we present review of support vector clustering technique for pattern detection and reorganisation for very large databases. The variation of performance of support vector clustering depends upon kernel of classifier. Here we discuss different method of kernel used in support vector clustering.
Efficient Voltage Regulation in Three Phase A.C. Transmission Lines Using Static VAR Compensator
International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering , 2013,
Abstract: Due to the rapid technological progress, the consumption of electric energy increases continuously. But the transmission systems are not extended to the same extent because building of new lines is difficult for environmental as well as political reasons. Hence, the systems are driven closer to their limits resulting in congestions and critical situations endangering the system security. Power Flow Control devices such as Flexible AC Transmission Systems (FACTS) provide the opportunity to in uence power ows and voltages and therefore to enhance system security, e.g. by resolving congestions and improving the voltage pro le. From the last few years static var compensator plays an important role in voltage regulation in AC Transmission Systems. This paper deals with the designing and implementation of Static Var compensator for Efficient Voltage regulation in three phase A.C. transmission lines in MATLAB Simulink platform.
An efficient Support Vector Clustering with combined core outlier and boundary value for pre-processing of data
Deepak Kumar Vishwakarma, Anurag Jain
International Journal of Advanced Computer Research , 2012,
Abstract: The performance of support vector clustering suffered Due to noisy data. The pre-processing of data play important role in support vector cluster. In support vector clustering the mapping of data from one sphere to another sphere found some unwanted behaviour of data, these behaviour are boundary point, core and outlier. These data point degrade the performance and efficiency of support vector clustering. For the reduction of core, outlier and boundary value, we combined all dissimilar data and form COB model and data passes through genetic algorithm for collective collection of COB and reduce the COB value in data pre-processing phase. After reduction of COB support vector clustering are applied. Our empirical evaluation shows that our method is better than incremental support vector clustering and SSN-SVC.
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