(SoE) School of Engineering

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

The paper presents a novel framework for large class, binary pattern classification problem by learning-based combination of multiple features. In particular, class of binary patterns including characters/primitives and symbols has been considered in the scope of this work. We demonstrate novel binary multiple kernel learning-based classification architecture for applications including such problems for fast and efficient performance. The character/primitive classification problem primarily concentrates on Gujarati and Bangla character recognition from the analytical and experimental context. A novel feature representation scheme for symbols images is introduced containing the necessary elastic and non-elastic deformation invariance properties. The experimental efficacy of proposed framework for symbol classification has been demonstrated on two public data sets. © 2014, Springer-Verlag Berlin Heidelberg.

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Electrical Engineering

International Journal on Document Analysis and Recognition

Feature combination for binary pattern classification

The practically important case of dielectric loaded tape helix enclosed in a perfectly conducting coaxial conductor is analysed in this paper. The dispersion equation for the infinitesimally thin and anisotropically conducting tape is derived from an exact solution of a homogeneous boundary value problem for Maxwell's equation. The boundary value problem is solved to yield the dispersion equation which takes the form of the solvability condition viz., the determinant of the infinite-order coefficient matrix is zero. For the numerical computation of the approximate dispersion characteristics, all the entries of the symmetrically truncated version of the coefficient matrix are estimated by summing an adequate number of the rapidly converging series for them. The numerical computation of dispersion characteristics and phase speed variations for different values of b/a (outer conductor to inner helix radius) and effective dielectric permittivity is presented. © 2014 IEEE.

IEEE International Vacuum Electronics Conference, IVEC 2014

Wave propagation characteristics in anisotropically conducting dielectric loaded tape helix slow wave structures

Speech feature extraction is the most significant step in any Automatic speaker recognition system. In the last 60 years a lot of research has gone into parametric representation of these speech features. Several techniques are currently being used for Automatic Speaker Recognition. Yet Automatic Speaker Recognition still remains a confront mainly due to variations in speaker's vocal tract with time and health, varying environmental conditions, disparities in the behavior and quality of speech recorders etc. MFCC is a extensively used technique in Automatic speaker recognition. In this paper the performance of MFCC technique was evaluated in a quiet environment. A speaker database containing 30 male and 30 female speakers was created. Two separate experiments were conducted for the performance evaluation of MFCC technique when applied to K means clustering. In the first case the speech features were directly matched. In the second case a VQ codebook was created by clustering the training features of these 60 speakers. A distortion easure based on the minimum Euclidean distance was used for speaker recognition. The failure rate of speaker recognition in first ase was found to be was found to be 10\% while in the second case as found to be 14\%. Matlab-7.10.0 was used for this study © 2014 IEEE.

ICROIT 2014 - Proceedings of the 2014 International Conference on Reliability, Optimization and Information Technology

Mel frequency cepstral coefficients based text independent Automatic Speaker Recognition using matlab

Evaporation-induced particle deposition patterns like coffee rings provide easy visual identification that is beneficial for developing inexpensive and simple diagnostic devices for detecting pathogens. In this study, the effect of chemotaxis on such pattern formation has been realized experimentally in drying droplets of bacterial suspensions. We have investigated the velocity field, concentration profile, and deposition pattern in the evaporating droplet of Escherichia coli suspension in the presence and absence of nutrients. Flow visualization experiments using particle image velocimetry (PIV) were carried out with E. coli bacteria as biological tracer particles. Experiments were conducted for suspensions of motile (live) as well as nonmotile (dead) bacteria. In the absence of any nutrient gradient like sugar on the substrate, both types of bacterial suspension showed two symmetric convection cells and a ring like deposition of particles after complete evaporation. Interestingly, the droplet containing live bacterial suspension showed a different velocity field when the sugar was placed at the base of the droplet. This can be attributed to the chemoattractant nature of the sugar, which induced chemotaxis among live bacteria targeted toward the nutrient site. Deposition of the suspended bacteria was also displaced toward the nutrient site as the evaporation proceeded. Our experiments demonstrate that both velocity fields and concentration patterns can be altered by chemotaxis to modify the pattern formation in evaporating droplet containing live bacteria. These results highlight the role of bacterial chemotaxis in modifying coffee ring patterns.

Chemical Engineering

Langmuir : the ACS journal of surfaces and colloids

Fluid flow and particle dynamics inside an evaporating droplet containing live bacteria displaying chemotaxis

Analysis of fluid flow and particle transport inside evaporating droplets exposed to external radiation was carried out by experiments and numerical simulations. In this study, we have shown that by altering the free surface temperature we can modify the fluid flow profile inside the droplet and hence the deposition pattern of solute particles on the substrate. The fluid velocity and particle concentration profiles inside the evaporating droplet were measured by Particle Image Velocimetry (PIV) technique. Experiments were carried out on a small sessile water droplet containing dispersed polystyrene particles. To avoid problem of image correction encountered in PIV measurements with 3D droplets, our experiments were performed on an equivalent disc shaped 2D drop sandwiched between two non-wetting surfaces, while the base of the droplet was pinned to a wetting surface. The top surface of the droplet was heated by Infrared (IR) light. The temperature of droplet surface was measured by thermocouples. The velocity field, particle concentration profile and particle deposition patterns were studied during evaporation process. We have also performed numerical simulations by solving continuity, momentum and energy transport equations. The computed velocity profiles resulting from buoyancy and Marangoni convection are in qualitative agreement with the experiments. © 2013 Elsevier Ltd. All rights reserved.

International Journal of Heat and Mass Transfer

Analysis of fluid flow and particle transport in evaporating droplets exposed to infrared heating

Volatile organic compounds (VOCs) prevalent in our atmosphere are of major environmental concerns. Several methods of controlling VOCs exist. Most of them have direct or indirect environmental consequences in terms of materials they use and wastes they produce albeit control VOCs. It has been found that conventional techniques especially of physical and chemical nature pose a number of problems such as high on cost, high material requirement, produce lots of waste and contribute to climate change and environmental degradation. Various biological oxidation methods adopted in various reactors for controlling gaseous VOCs have been reviewed, pros and cons of these technologies have been studied and the sensitive parameters for improving removal efficiency along with their environmental implications have been identified. It has been found that rotating biological contactor (RBC) could be an effective alternative to control gaseous VOCs because of its simple design and operation. Further, it provides higher oxygen transfer, offers better mixing, consumes low energy and has potential of higher removal efficiency as compared to the other biological techniques. There is, moreover, an ample scope in improving its gaseous-control efficiency by optimizing the parameters like rotational speed, hydraulic loading rate, and hydraulic retention time and similarly by the use of different media, biofilm characteristics and dissolved-oxygen levels. With these scopes, RBC can be an eco-friendly, and promising option for controlling gaseous VOCs. © 2014 Elsevier Ltd. All rights reserved.

Civil Engineering

Journal of Environmental Chemical Engineering

Biological oxidation of gaseous VOCs - Rotating biological contactor a promising and eco-friendly technique

In the present work, the slurry erosion behavior of friction stir processed (FSPed) hydroturbine steel (CA6NM) was investigated. For comparison, the erosion performance of unprocessed CA6NM steel was evaluated under similar conditions. Friction stir processing (FSP) is a microstructural refinement tool which is useful in enhancing the bulk and surface properties of materials. An in-depth characterization of both steels was done using an optical microscope (OM), a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS), the electron backscatter diffraction (EBSD) technique, and micro- and nano-indentation techniques. The FSP of the steel helped in reducing the erosion rates by 50% to 60%, depending upon the impingement angle. The improved performance of the FSPed steel in comparison to unprocessed steel was attributed to microstructural refinement, which increased the hardness and yield strength. At an oblique impingement angle, plowing, along with microcutting, was observed to be the dominant erosion mechanism. At a normal impingement angle, the material removal process was controlled by the platelet mechanism of erosion. A modified form of the mathematical model for predicting the erosion rates of the ductile materials, proposed by authors earlier, was also presented. This modified model based upon the theory of plasticity was able to predict the erosion rates with an accuracy of ±20%. Copyright © 2014 by ASME.

Mechanical Engineering

Journal of Tribology

Improving erosion resistance of hydroturbine steel using friction stir processing

Photovoltaic (PV) arrays produce less power than the array rating due to shading on the array. Since the modules of the arrays receive different solar irradiation, the powervoltage characteristics of photovoltaic (PV) arrays contain multiple local maxima. This paper presents a novel approach to arrange the physical position of modules in Totally Cross Tied (TCT) configuration, without changing the electrical connection of the modules in the array, in such a way that there is an increase of power generation of array under partial shading condition. The modules of TCT configuration are rearranged in such a way that the shading effect is distributed over the array, and it reduces the multiple local maxima in power-voltage characteristics of PV array. Hence tracking of global maximum power point (GMPP) in the present approach is simpler. In this paper, the power generation of array with TCT and proposed configuration is compared. It is demonstrated that the power generation of array with proposed configuration is enhanced under different shading pattern. © 2014 IEEE.

2014 IEEE Innovative Smart Grid Technologies - Asia, ISGT ASIA 2014

Power enhancement of partially shaded PV array by using a novel approach for shade dispersion

The paper presents a novel framework for the application of multiple features for handwritten data based identity recognition. Different types of features characterise different facets of the handwriting. We have designed a scheme for multiple feature based identity establishment using multi-kernel learning. A new formulation for multi-kernel learning using genetic algorithm has been presented. The efficacy of the framework using individual and combination of features is demonstrated for Devanagari script input. © 2013 Elsevier B.V. All rights reserved.

Pattern Recognition Letters

Off-line hand written input based identity determination using multi kernel feature combination

The buckling of conductors of inner windings in transformers is one of the major causes of their failures. It can occur when a large magnitude of radial short-circuit electromagnetic force acts on them. In this paper, initially, mechanical strains developed during winding processes and due to radial short-circuit forces have been determined. The two mechanical strains viz. the short-circuit induced strain and the winding process-induced strain are algebraically added to obtain their resulting strain. The stress corresponding to the resulting strain has been determined by using the Ramberg-Osgood stress-strain relation. The critical buckling stress has been calculated and compared with the resulting stress. The analytically obtained result of the strain induced in the winding conductor during its winding process has been verified using the finite-element method. A case study has been described in which the factor of safety against the buckling strength is determined. © 1986-2012 IEEE.