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Greater Noida, India

Saxena R.,Jaypee University | Joshi H.D.,Thapar University
Pertanika Journal of Science and Technology | Year: 2014

The Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier modulation (MCM) technique which is adopted by many wireless communication standards for transmitting data at very high rates over time dispersive radio channels. In an OFDM system, the timing estimation is extremely important for maintaining orthogonality among the subcarriers. In this paper, a method of timing estimation is proposed for an OFDM system. The proposed method used chirp signal as a training sequence and employed the fractional Fourier transform (FRFT) as a tool to localize the training sequence (chirp) at the receiver. The comparative study showed the superiority of the proposed estimator in terms of mean and MSE of timing offset. The MSE of timing offset with proposed method was found to be 76% (5 dB SNR) and 63% (8 dB SNR) lower than Awoseyila et al.’s method in HIPERLAN/2 indoor channel-A and in Wi-Max system (strong fading channel), respectively. However, the improvement in MSE is obtained in the proposed method at the cost of increased computational complexity, in terms of (Formula presented)more complex multiplication than the Awoseyila et al.’s method. © 2014 Universiti Putra Malaysia Press. Source

Sharma S.,Jaypee University of Engineering & Technology | Dubey S.R.,Indian Institute of Information Technology Allahabad | Singh S.K.,Indian Institute of Information Technology Allahabad | Saxena R.,Jaypee University | Singh R.K.,Indian Institute of Information Technology Allahabad
Expert Systems with Applications | Year: 2015

A multimodal biometric system for personal identity verification is proposed using hand shape and hand geometry in this paper. Shape and geometry features are derived with the help of only contour of the hand image for which only one image acquisition device is sufficient. All the processing is done with respect to a stable reference point at wrist line which is more stable as compared to the centroid against the finger rotation and peaks and valleys determination. Two shape based features are extracted by using the distance and orientation of each point of hand contour with respect to the reference point followed by wavelet decomposition to reduce the dimension. Seven distances are used to encode the geometrical information of the hand. Shape and geometry based features are fused at score levels and their performances are evaluated using standard ROC curves between false acceptance rate, true acceptance rate, equal error rate and decidability index. Different similarity measures are used to examine the accuracy of the introduced method. Performance of system is analyzed for shape based (distance and orientation) and geometrical features individually as well as for all possible combinations of feature and score level fusion. The proposed features and fusion methods are studied over two hand image datasets, (1) JUET contact database of 50 subjects having 10 templates each and (2) IITD contactless dataset of 240 subjects with 5 templates each. The proposed method outperforms other approaches with the best 0.31% of EER. © 2014 Elsevier Ltd. All rights reserved. Source

Pundir S.S.,Jaypee Institute of Information Technology | Mishra K.,Jaypee University | Rai D.K.,Jaypee Institute of Information Technology
Solid State Ionics | Year: 2015

Proton conducting polymer electrolyte membranes consisting of poly(vinyl)alcohol and 1-butyl-3-methylimidazolium hydrogen sulfate ionic liquid are prepared by solution cast technique. The membranes are found to be free-standing and mechanically stable for the 40, 60 and 80 wt.% concentration of ionic liquid. The membranes have been characterized by X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, complex impedance spectroscopy and cyclic voltammetry. The crystallinity and melting point of the membranes are found to decrease with increasing concentration of ionic liquid. The membrane with 80 wt.% ionic liquid has been found to be completely amorphous. The highest ionic conductivity has been found to be ~ 10- 3 S cm- 1 at room temperature for the membrane with 80 wt.% ionic liquid. The variation of ionic conductivity with temperature follows Arrhenius type behavior in the temperature range of 40-130°C. The membranes show protonic conduction as established by cyclic voltammetry and complex impedance spectroscopic studies. The electrochemical window of the membranes has been found to be ~ 3.4 V. © 2015 Elsevier B.V. All rights reserved. Source

Sharma V.,Thapar University | Kumar R.,Thapar University | Rathore N.,Jaypee University
Journal of Wireless Mobile Networks, Ubiquitous Computing, and Dependable Applications | Year: 2015

Ad hoc networks have been used in wide range of applications. These networks have become versatile as far implementation is concerned. Such networks have been used from static deployment to mobile network formations. Apart from Mobile Ad Hoc Networks (MANETs) and Vehicular Ad Hoc Networks (VANETs), another ad hoc formation with mobile nodes is the aerial ad hoc networks also termed as Flying Ad Hoc Networks (FANETs). A coordinated network formation between the ground ad hoc network and aerial ad hoc network provides vast applications in both civilian and military activities. Various existing issues of mobile networks can easily be resolved using aerial network formations. However, these networks similar to the traditional ad hoc formations are having a major issue of broadcast storming and network partitioning. These issues hinder the performance of such networks. Broadcast storming refers to replication of similar data in the network that increases the overheads which ultimately leads to network failure. In this paper, broadcast storming is considered as a problem and a possible solution is provided for it by keeping control over network partitioning issues. The proposed approach uses parameter sensitivity which is derived over optimized value of nodes configurations to form a topological arrangement. This topological arrangement is formed using logical proximity graphs which operate over link weight and parameter sensitivity. The proposed route discovery strategy under the proposed approach is capable of handling issues related to broadcast storms without affecting the network performance. © 2015, Innovative Information Science and Technology Research Group. All rigths reserved. Source

Pathak B.K.,Jaypee University | Srivastava S.,Dayalbagh Educational Institute
Iranian Journal of Fuzzy Systems | Year: 2015

This study presents the effects of project uncertainties on non- linear time-cost tradeoff (TCT) profile of real life engineering projects by the fusion of fuzzy logic and artificial neural network (ANN) models with hybrid meta-heuristic (HMH) technique, abridged as Fuzzy-ANN-HMH. Nonlinear time-cost relationship of project activities is dealt with ANN models. ANN models are then integrated with HMH technique to search for Pareto-optimal nonlinear TCT profile. HMH technique incorporates simulated annealing in the selection process of multiobjective genetic algorithm. Moreover, in real life engineering projects, uncertainties like management experience, labor skills, and weather conditions are commonly involved, which affect the duration and cost of the project activities. Fuzzy-ANN-HMH analyses responsiveness of nonlinear TCT profile with respect to these uncertainties. A comparison of Fuzzy-ANN-HMH is made with another method in literature to solve nonlinear TCT problem and the superiority of Fuzzy-ANN-HMH is demonstrated by results. The study gives project planners to carry out the best plan that optimizes time and cost to complete a project under uncertain environment. © 2015, University of Sistan and Baluchestan. All rights reserved. Source

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