Mouangue R.,University Institute of Technology |
Obounou M.,University of Yaounde I |
Mura A.,CNRS Pprime Institute
International Journal of Hydrogen Energy | Year: 2014
This paper reports results of numerical simulations of a turbulent lifted jet flame of hydrogen-nitrogen mixtures including the effects of the autoignition. The impact of burned gases on the flame stabilization is analysed under the conditions of a laboratory jet flame in a vitiated coflow. In this study, mass flow rate, temperature and exact chemical composition of hot products mixed with air sent toward the turbulent flame base are fully determined. The effects of both non-infinitely fast chemistry and partially premixed combustion are taken into account within a Lagrangian intermittent framework. Detailed chemistry effects are incorporated through the use of a tabulation delay. The concept of residence time of the particles and the transport equation for the mean scalar dissipation rate are included. Numerical simulation of the turbulent diluted jet flame of H2/N2 studied by Cabra and his co-workers at Berkeley University is performed and satisfactory results are obtained: the flame liftoff height is reasonably captured and the predictions display a reasonable agreement with respect to experimental data. © 2014 Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Burse K.,Truba Institute of Engineering and Information Technology |
Pandey A.,University Institute of Technology |
Somkuwar A.,Maulana Azad National Institute of Technology
Proceedings - 2011 International Conference on Computational Intelligence and Communication Systems, CICN 2011 | Year: 2011
In a complex valued neural network (CVNN) the weights, threshold, inputs and outputs are all complex numbers. Researchers have proposed many complex activation functions which can approximate a continuous complex valued function for CVNN node processing. The choice of an activation function determines the convergence of the complex back propagation algorithm and its generalization characteristics. In this paper we have compared the performance of various activation functions on the complex XOR problem for the complex multiplicative neural network. © 2011 IEEE.
Patel R.,University Institute of Technology
The Scientific World Journal | Year: 2013
Region duplication forgery detection is a special type of forgery detection approach and widely used research topic under digital image forensics. In copy move forgery, a specific area is copied and then pasted into any other region of the image. Due to the availability of sophisticated image processing tools, it becomes very hard to detect forgery with naked eyes. From the forged region of an image no visual clues are often detected. For making the tampering more robust, various transformations like scaling, rotation, illumination changes, JPEG compression, noise addition, gamma correction, and blurring are applied. So there is a need for a method which performs efficiently in the presence of all such attacks. This paper presents a detection method based on speeded up robust features (SURF) and hierarchical agglomerative clustering (HAC). SURF detects the keypoints and their corresponding features. From these sets of keypoints, grouping is performed on the matched keypoints by HAC that shows copied and pasted regions. © 2013 Parul Mishra et al.
Kulshrestha M.,Maulana Azad National Institute of Technology |
Vishwakarma A.,University Institute of Technology
Water Policy | Year: 2013
Water supply services in urban India are essential functions of urban local bodies or municipalities. These services are mostly perceived as unsatisfactory across urban centres and the sector is widely perceived to be misgoverned with large number of municipalities making financial losses. However, this common perception of inefficient services has not much scientific basis as the efficiencies of these services are not measured. This paper, therefore, attempts to evolve a framework for evaluating the relative inefficiencies of water supply services and applies a non-parametric approach, data envelopment analysis (DEA), to 20 urban centres in the state of Madhya Pradesh in India, by applying three different models. The results of the analysis indicate that there are significant inefficiencies amongst the various municipalities that supply water. It was found that larger cities exhibit better efficiencies than smaller ones, requiring policy interventions. However, even the larger municipalities need restructuring and downsizing of their operations to be more efficient. DEA results also show that significant savings with respect to operating expenditures, staff and non-revenue water are actually possible if best practices are adopted. The paper discusses the results of the study in the context of policy issues that are relevant from a developing country perspective. © IWA Publishing 2013.
Singh B.,University Institute of Technology |
Jain S.,MANIT Bhopal
IET Power Electronics | Year: 2013
The availability of limited voltage vectors in a conventional direct torque control drive fed from a two-level inverter causes torque and current ripples. In this study, a new torque ripple reduction technique with a modified look up table incorporating a larger number of synthesised non-zero active voltage vectors is proposed to overcome the limitations of the conventional and duty ratio control switching strategies. The voltage vector selection criteria in the proposed technique are based to prevent the stator flux demagnetisation during the low-speed operation with significant reduction in torque and current ripple. The proposed switching strategy is investigated through simulation and experimentally validated on a test drive.