(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

This paper brings into focus some of the interesting effects arising from the motion of the liquid free surface due to sloshing in partially filled containers of several geometrical shapes in two dimensions. The slosh characteristics that include frequencies, free surface profiles and the hydrodynamic pressure over the container walls have been reported in this study. The equations of motion of the fluid, considered inviscid, are expressed in terms of the pressure variable alone. It is assumed that the frequency of the exciting oscillation is not in the immediate neighborhood of the natural slosh frequency, so that the slope of the free surface is small. Simple harmonic oscillation and earthquake excitations are used as the prescribed boundary conditions. A finite difference-based iterative time-stepping technique is employed to advance the solution in the time domain. The paper presents numerical solutions for rectangular, vertically mounted annular cylindrical, trapezoidal and horizontal circular cylindrical containers. Numerical results obtained are compared with the available existing solutions to validate the code developed. The parametric study of the slosh dynamic systems shows the importance of the nature of excitation, fluid height and the geometry of the container. Copyright © 2007 John Wiley & Sons, Ltd.

Mechanical Engineering

World University root node

International Journal for Numerical Methods in Fluids

Slosh dynamics of inviscid fluids in two-dimensional tanks of various geometry using finite element method

The problem of sorting has been studied extensively and many algorithms have been suggested in the literature for the problem. Literature on parallel sorting is abundant. Many of the algorithms proposed, though being theoretically important, may not perform satisfactorily in practice owing to large constants in their time bounds. The algorithms presented in this paper have the potential of being practical. We suggest some novel sorting mechanisms specific to the Cell Broadband engine. We try to utilize the specifics of its architecture in order to get the optimum performance. As part of our comparative analysis we juxtapose these algorithms with similar ones implemented on Itanium 2 processor as well as the Pentium 4 processor. © 2008 IEEE.

Computer Science and Engineering

Proceedings - IEEE Symposium on Computers and Communications

Efficient sorting algorithms for the cell broadband engine

An attempt has been made to correlate the morphological and electrical properties of RF sputtered aluminum nitride (AlN), with target to substrate distance (D ts) in sputter chamber. AlN films, having thickness around 3,000 Å, were deposited on silicon substrates with different D tsvalues varying from 5 to 8 cm. XRD results indicated that the crystallinity of c-axis oriented films increase significantly with decrease in D ts and the FTIR absorption band of the films became prominent at shorter D ts. The surface roughness increased from 1.85 to 2.45 nm with that in D ts. A smooth surface with smaller grains was found at shorter D ts. The capacitance-voltage (C-V) measurements revealed that the insulator charge density (Q in) increased from 3.3 × 10 11 to 7.3 × 10 11 cm -2and the interface state density (D it) from 1.5 × 10 11 to 7.3 × 10 11 eV -1cm -2 with the increase in D ts. © Springer Science+Business Media, LLC 2007.

Electrical Engineering

Journal of Materials Science: Materials in Electronics

Effect of inter-electrode spacing on structural and electrical properties of RF sputtered AlN films

The boiler is a very important component of a thermal power plant, and its efficient operation requires continuous online information of various relevant parameters. Furnace exit gas temperature (FEGT) is one such important design/operating parameter. Knowledge of FEGT is not only useful for design of convective heating surface but also helpful for operating actions and decision making. Its online information ensures improvement in economic benefit of the power plant. Non-availability of FEGT on the operator desk greatly limits efficient operation. In this study, a novel method of estimating FEGT using neural network is presented. The training data are first generated by calculating FEGT using heat balances through various heat exchangers. Prediction accuracy and fast response are major advantages in using neural network for estimating FEGT for operator information. Two types of feed forward neural modeling networks, radial basis function and back-propagation network, were applied and compared based on their network simplicity, model building and prediction accuracy. Results are verified on practical data obtained from a 210 MW boiler of a thermal power plant. © 2008 Elsevier Ltd. All rights reserved.

Energy Conversion and Management

Estimation of furnace exit gas temperature (FEGT) using optimized radial basis and back-propagation neural networks

IEEE transactions on electron devices

Drain current model including velocity saturation for symmetric double-gate MOSFETs

Closed form current and conductance model for symmetric double-gate MOSFETs using field-dependent mobility and body doping

In this paper, a Hamilton-Jacobi-Bellman (HJB) equation based optimal control algorithm is proposed for a bilinear system. Utilizing the Lyapunov direct method, the controller is shown to be optimal with respect to a cost functional, which includes penalty on the control effort and the system states. In the proposed algorithm, Neural Network (NN) is used to And approximate solution of HJB equation using least squares method. Proposed algorithm has been applied on bilinear systems. Necessary theoretical and simulation results are presented to validate proposed algorithm. © 2008 IEEE.

Proceedings of the International Joint Conference on Neural Networks

Constrained optimal control of bilinear systems using neural network based HJB solution

Thorup and Zwick, in the seminal paper [Journal of ACM, 52(1), 2005, pp 1-24], showed that a weighted undirected graph on n vertices can be preprocessed in subcubic time to design a data structure which occupies only subquadratic space, and yet, for any pair of vertices, can answer distance query approximately in constant time. The data structure is termed as approximate distance oracle. Subsequently, there has been improvement in their preprocessing time, and presently the best known algorithms [4,3] achieve expected O(n 2) preprocessing time for these oracles. For a class of graphs, these algorithms indeed run in Θ(n2) time. In this paper, we are able to break this quadratic barrier at the expense of introducing a (small) constant additive error for unweighted graphs. In achieving this goal, we have been able to preserve the optimal size-stretch trade offs of the oracles. One of our algorithms can be extended to weighted graphs, where the additive error becomes 2·wmax (u,v) - here wmax(u,v) is the heaviest edge in the shortest path between vertices u, v. © 2008 Springer-Verlag.

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Distance oracles for unweighted graphs: Breaking the quadratic barrier with constant additive error

We present a new multiscale model for failure analysis of thin composite structures. The present model is based on the asymptotic homogenization method with multiple spatial scales. The proposed approach is a generalization of the elastostatic Caillerie-Kohn-Vogelius theory to study the failure mechanics of thin composite plates under static and dynamic loads. We employ a model reduction methodology based on the eigendeformation concept to minimize the computational burden. An efficient n-partition computational homogenization model is developed for simulation of large scale structural systems without significantly compromising on the solution accuracy. The proposed model is verified against direct 3-D finite element simulations.

Civil Engineering

American Society for Composites - 23rd Technical Conference of the American Society for Composites 2008

A multiscale failure model for thin heterogeneous plates

In this paper, design and implementation of an optimized controller for a single magnet-based electromagnetic levitation system (EMLS) where an electromagnet of 2.6-kg mass is levitated over a large gap under a fixed ferromagnetic guide-way has been discussed. EMLS is inherently unstable and strongly nonlinear in nature. A single position controller (lead type) along with an outer proportional-integral (PI) controller has been designed that will stabilize the EMLS represented mathematically by three different plants corresponding to three different operating points. An optimization technique utilizing the random search method with interval reduction, proposed by Luus and Jaakola, has been used for designing the controller. A "model matching control" design procedure has been utilized for the design of outer PI controller. The inner controller stabilizes the three unstable plants, whereas the outer PI control action is used to modify the three position outputs as per the desired model response. The combined control action provides good stability and satisfactory performance (like fast response, less overshoot, and zero steady-state error) for the different operating zones of EMLS. Stability has been confirmed by Kharitonov-Nyquist enclosure diagrams. The simulated controllers have been successfully implemented, thus validating the modeling and controller design procedure. © 2008 IEEE.