Entity

Time filter

Source Type

Ajmer, India

Savescu M.,Delaware State University | Savescu M.,University of Pennsylvania | Khan K.R.,Humber College | Naruka P.,Engineering College | And 3 more authors.
Journal of Computational and Theoretical Nanoscience | Year: 2013

This paper studies the dynamics of optical solitons with an improved nonlinear Schrödinger's equation that models the propagation of solitons through nano optical fibers. The traveling wave hypothesis as well as the ansatz method will be applied to extract bright and dark soliton solutions of this model. There are five types of nonlinearities that will be studied. They are Kerr law, power law, parabolic law, dual-power law and log law nonlinearity. Copyright © 2013 American Scientific Publishers All rights reserved. Source


Jain S.K.,P.A. College | Panda G.,Engineering College | Vijay S.K.,P.A. College
Indian Journal of Physics | Year: 2010

The present work deals with the anomalies in ionospheric slab thickness of F-region associated with strong seismic activity. In this regard we have considered ionosonde data of Critical frequency of F2 layer (foF2) and Ionospheric Total Electron Content (ITEC) observed for Athens [38°N, 24°E] and Rome [42°N, 13°E] stations. We have considered three cases of earthquake occurring on December 20, 2007, June 08, 2008 and April 06, 2009 and analyzed the ionosonde data of foF2 and ITEC for slab thickness of F-region of the ionosphere in one-hour interval time series record by filtering the geomagnetic disturbances. The result of the study shows that some unusual perturbations were observed in slab thickness of F-region for some days before the main seismic event. It may be due to the generation of seismogenic electric field above the surface of the earth well before the seismic event. This anomalous behavior of perturbations may be used as earthquake precursor. © 2010 IACS. Source


Soni D.P.,Sardar Vallabhbhai Patel Institute of Technology | Mistry B.B.,Engineering College | Panchal V.R.,Sardar Vallabhbhai Patel Institute of Technology
Structural Engineering and Mechanics | Year: 2010

Presented in this paper is the behaviour of asymmetric building isolated by the double variable frequency pendulum isolator (DVFPI). The DVFPI is an adoption of single variable frequency pendulum isolator (VFPI). The geometry and coefficient of friction of top and bottom sliding surfaces can be unequal. The governing equations of motion of the building-isolation system are derived and solved in incremental form. The analysis duly considers the interaction of frictional forces in the two principal directions developed at each sliding surface of the DVFPI. In order to investigate the behaviour of the base isolation using the DVFPI, the coupled lateral-torsional response is obtained under different parametric variations for a set of six far-fault earthquake ground motions and criterion to optimize its performance is proposed. Further, influences of the initial time period, coefficient of friction and frequency variation factors at the two sliding surfaces are investigated. The numerical results of the extensive parametric study help in understanding the torsional behaviour of the structure isolated with the double sliding surfaces as in the DVFPI. It is found that the performance of the DVFPI can be optimized by designing the top sliding surface initially softer and smoother relative to the bottom one. Source


Soni D.P.,Sardar Vallabhbhai Patel Institute of Technology | Mistry B.B.,Engineering College | Jangid R.S.,Indian Institute of Technology Bombay | Panchal V.R.,Sardar Vallabhbhai Patel Institute of Technology
Structural Control and Health Monitoring | Year: 2011

The double variable frequency pendulum isolator (DVFPI) is an adaptation of single variable frequency pendulum isolator (VFPI). The principle benefit of the DVFPI is its capacity to accommodate larger displacements compared to the VFPI of identical plan dimensions. Moreover, there is the capability to use sliding surfaces with varying isolator geometry and coefficients of friction of top and bottom sliding surfaces, giving the designer greater flexibility to optimize performance. This paper describes the mathematical modeling and force-displacement relationships of the DVFPI. Behavior of the DVFPI is studied by varying isolator geometry and coefficient of friction of the two sliding surfaces and criteria to optimize the performance of the DVFPI are proposed. Further, influences of the initial time period, the coefficient of friction and the frequency variation factors at the two sliding surfaces are investigated. The combined effect of change in the initial time period and the coefficient of friction on the seismic response of the DVFPI is also studied. It is observed that the best performance of the DVFPI can be achieved by designing it with different friction coefficient and different initial time period of the two sliding surfaces. Copyright © 2010 John Wiley & Sons, Ltd. Source


Ai B.,Beijing Jiaotong University | Ai B.,Engineering College | Cheng X.,Peking University | Kurner T.,TU Braunschweig | And 7 more authors.
IEEE Transactions on Intelligent Transportation Systems | Year: 2014

High-speed railway (HSR) brings convenience to peoples' lives and is generally considered as one of the most sustainable developments for ground transportation. One of the important parts of HSR construction is the signaling system, which is also called the 'operation control system,' where wireless communications play a key role in the transmission of train control data. We discuss in detail the main differences in scientific research for wireless communications between the HSR operation scenarios and the conventional public land mobile scenarios. The latest research progress in wireless channel modeling in viaducts, cuttings, and tunnels scenarios are discussed. The characteristics of nonstationary channel and the line-of-sight (LOS) sparse and LOS multiple-input-multiple-output channels, which are the typical channels in HSR scenarios, are analyzed. Some novel concepts such as composite transportation and key challenging techniques such as train-to-train communication, vacuum maglev train techniques, the security for HSR, and the fifth-generation wireless communications related techniques for future HSR development for safer, more comfortable, and more secure HSR operation are also discussed. © 2000-2011 IEEE. Source

Discover hidden collaborations