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Ahmadabad, India

Ahmedabad University is a private university in Ahemedabad, Gujarat, India. It was established in July 2009. It is a self-financed, non-affiliated private university promoted by Ahmedabad Education Society . Wikipedia.

Dabhi V.K.,Dharmsinh Desai University | Chaudhary S.,Ahmedabad University
Natural Computing

Empirical modeling, which is a process of developing a mathematical model of a system from experimental data, has attracted many researchers due to its wide applicability. Finding both the structure and appropriate numeric coefficients of the model is a real challenge. Genetic programming (GP) has been applied by many practitioners to solve this problem. However, there are a number of issues which require careful attention while applying GP to empirical modeling problems. We begin with highlighting the importance of these issues including: computational efforts in evolving a model, premature convergence, generalization ability of an evolved model, building hierarchical models, and constant creation techniques. We survey and classify different approaches used by GP researchers to deal with the mentioned issues. We present different performance measures which are useful to report the results of analysis of GP runs. We hope this work would help the reader by facilitating to understand key concepts and practical issues of GP and steering in selection of an appropriate approach to solve a particular issue effectively. © 2014, Springer Science+Business Media Dordrecht. Source

Bhatt J.S.,Dhirubhai Ambani Institute of ICT | Joshi M.V.,Dhirubhai Ambani Institute of ICT | Raval M.S.,Ahmedabad University
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

In this paper, we propose a two-step Bayesian approach to handle the ill-posed nature of the unmixing problem for accurately estimating the abundances. The abundances are dependent on the scene contents and they represent mixing proportions of the endmembers over an area. In this work, a linear mixing model (LMM) is used for the image formation process in order to derive the data term. In the first step, a Huber-Markov random field (HMRF)-based prior distribution is assumed to model the dependencies within the abundances across the spectral space of the data. The threshold used in the HMRF prior is derived from an initial estimate of abundances obtained using the matched filters. This makes the HMRF prior data-driven, i.e., dHMRF. Final abundance maps are obtained in the second step within a maximum a posteriori probability (MAP) framework, and the objective function is optimized using the particle swarm optimization (PSO). Theoretical analysis is carried out to show the effectiveness of the proposed method. The approach is evaluated using the synthetic and real AVIRIS Cuprite data. The proposed method has the following advantages. 1) The estimated abundances are resistant to noise since they are based on an initial estimate that has high signal-to-noise ratio (SNR). 2) The variance in the abundance maps is well preserved since the threshold in the dHMRF is derived from the data. © 2014 IEEE. Source

Sharma V.,Indian Institute of Toxicology Research | Sharma V.,University of Bradford | Sharma V.,University of North Carolina at Chapel Hill | Anderson D.,University of Bradford | And 2 more authors.

The wide scale use of Zinc oxide (ZnO) nanoparticles in the world consumer market makes human beings more prone to the exposure to ZnO nanoparticles and its adverse effects. The liver, which is the primary organ of metabolism, might act as a major target organ for ZnO nanoparticles after they gain entry into the body through any of the possible routes. Therefore, the aim of the present study was to assess the apoptotic and genotoxic potential of ZnO nanoparticles in human liver cells (HepG2) and the underlying molecular mechanism of its cellular toxicity. The role of dissolution in the toxicity of ZnO nanoparticles was also investigated. Our results demonstrate that HepG2 cells exposed to 14-20 lg/ml ZnO nanoparticles for 12 h showed a decrease in cell viability and the mode of cell death induced by ZnO nanoparticles was apoptosis. They also induced DNA damage which was mediated by oxidative stress as evidenced by an increase in Fpg sensitive sites. Reactive oxygen species triggered a decrease in mitochondria membrane potential and an increase in the ratio of Bax/ Bcl2 leading to mitochondria mediated pathway involved in apoptosis. In addition, ZnO nanoparticles activated JNK, p38 and induced p53Ser15 phosphorylation. However, apoptosis was found to be independent of JNK and p38 pathways. This study investigating the effects of ZnO nanoparticles in human liver cells has provided valuable insights into the mechanism of toxicity induced by ZnO nanoparticles. © Springer Science+Business Media, LLC 2012. Source

Gene therapy has been recently shown as a promising tool for cancer treatment as nanotechnology-based safe and effective delivery methods are developed. Generally, genes are wrapped up in extremely tiny nanoparticles which could be taken up easily by cancer cells, not to their healthy neighboring cells. Several nanoparticle systems have been investigated primarily to address the problems involved in other methods of gene delivery and observed improved anticancer efficacy suggesting that nanomedicine provides novel opportunities to safely deliver genes, thus treat cancer. In this review, various nanoparticle types and related strategies, used in gene delivery for cancer treatment, have been discussed. © 2013 by Tabriz University of Medical Sciences. Source

Sharma R.,Ahmedabad University
International Journal of Power Electronics and Drive Systems

In this paper, a new soft switched cell that overcomes most of the drawbacks of the normal "hard switched-pulse width modulation" converter is proposed to contrive a new family of soft switched PWM converters. All of the semiconductor devices in this converter are turned on and off under exact or near zero voltage switching (ZVS) and/or zero current switching (ZCS). No additional voltage and current stresses on the main switch and main diode occur. A push-pull converter equipped with the proposed snubber cell is analyzed in detail. The predicted operation principles and theoretical analysis of the presented converter are verified with a prototype of a 50W PWM push-pull multi-output converter with insulated MOSFET and for regulation of slave outputs magnetic amplifier post regulators are considered as post regulators. Moreover; this multioutput converter has a simple structure, low cost, and ease of control circuitry. © 2013 Institute of Advanced Engineering and Science. All rights reserved. Source

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