We study cumulative scattering effects on wave front propagation in time dependent randomly layered media. It is well known that the wave front has a deterministic characterization in time independent media, aside from a small random shift in the travel time. That is, the pulse shape is predictable, but faded and smeared as described mathematically by a convolution kernel determined by the auto...

Many cosmological models of GRBs envision the energy source to be a cataclysmic stellar event leading to a relativistically expanding fireball. Particles are thought to be accelerated at shocks and produce nonthermal radiation. The highly variable temporal structure observed in most GRBs has significantly constrained models. By using different methods of statistical analysis in the time domain ...

Based on a 3×3 mass matrix describing the mixing of the scalar states f0(1370), f0(1500) and f0(1710), the hadronic decays of the three states are investigated. Taking into account the two possible assumptions concerning the mass level order of the bare states |N〉 = |uū + dd̄〉/ √ 2, |S〉 = |ss̄〉 and |G〉 = |gg〉 in the scalar sector, MG > MS > MN and MG > MN > MS , the glueball-quarkonia content of ...

The results of a numerical investigation of the electromagnetic scattering from two-dimensional (2-D) targets on a time-evolving sea surface are presented. The 2-D radar cross section (RCS), or “echo width,” is computed as a function of time as the sea surface evolves linearly using the spectrally accelerated generalized forward-backward method. It is shown that the RCS varies with time on the ...

Three-dimensional numerical computations were carried out to understand the overlap effect of the transmitted pulses in a cubic participating medium subjected to a diffuse square pulse train using the transient discrete ordinates method with the pulse boundary condition. In concrete terms, the effects of the pulse width and pulse train interval on the divergence of radiative heat flux were scru...

An experimental comparative study of various controllers for a class of ac–dc converters, known as power factor precompensators (PFP) is presented. The control objective is to robustly regulate the output voltage to a desired constant level in the presence of variations in the load, while retaining a unit power factor at the input, i.e., the input current should follow in frequency and in phase...

Modified-Electroconvulsive Therapy (m-ECT) is administered for the treatment of various psychiatric disorders. The Seizure Generalization Hypothesis holds that propagation of the induced seizure throughout the whole brain is essential for the effective ECT intervention. However, we encounter many clinical cases where, due to high thresholds, seizure is not induced by the maximum dose of electri...

Analysis and minimization of output current ripple of multiphase carrier-based PWM inverters are presented in this paper. Analytical expression of rms value of output current ripple of multiphase PWM inverters as a function of the reference signal is first derived. Based on this expression, it is shown that a pure sinusoidal signal is the optimum reference signal that results in minimum output ...

The development of consistent and stable quasicontinuum models for multidimensional crystalline solids remains a challenge. For example, proving the stability of the force-based quasicontinuum (QCF) model [M. Dobson and M. Luskin, M2AN Math. Model. Numer. Anal., 42 (2008), pp. 113–139] remains an open problem. In one and two dimensions, we show that by blending atomistic and Cauchy–Born continu...

Limit cycle oscillations of rotor speed are substantially caused by inverter’s dead time, when an induction motor (IM) drive operates in low frequency condition. In this paper, without any hardware modification, discontinuous PWM (DPWM3) modulate strategy possibly controls the unfavorable rotor speed limit cycle under no load operation condition. Simulated results are presented to demonstrate t...