A finite-difference time-domain (FDTD) algorithm has been developed to model linear infrasound propagation through a windy, viscous medium. The algorithm has been used to model signals from a large bolide that burst above a dense seismic network in the US Pacific Northwest on 19 February, 2008. We compare synthetics that have been computed using a G2S-ECMWF atmospheric model to signals recorded...

Free Electron Lasers (FELs) are the only radiation sources generating electromagnetic from THz to hard X-rays. Therefore, it is crucial to develop rigorous simulation tools. Our work is motivated by the desire to develop compact X-ray sources based on radiation generated with optical undulators. The currently existing softwares are usually written to tackle special cases allowing for particular...

In this paper, the finite difference time domain method in spherical coordinates is used to analyze a microstrip conical antenna with a dielectric electromagnetic band-gap (EBG) structure as substrate. The voltage standing wave ratio, matched impedance, maximum gain as well as far-field radiation patterns, are presented. Our study suggests that the microstrip conical antenna on EBG substrate ho...

We consider a time-dependent problem of scattering by an obstacle involving the solution of the two dimensional Maxwell’s equations in the exterior of a domain with a perfectly conducting condition on the boundary of this domain. We propose a novel fictitious domain method based on a distributed Lagrange multiplier technique for the solution of this problem. Perfectly matched layers are constru...

Microwave heating–drying of wood using a wave guide is a relatively new area of research. In order to gain insight into the phenomena that occur within the wave guide together with the temperature distribution in the wood, a detailed knowledge of absorbed power distribution is necessary. In this paper, a two dimensional numerical model is developed to predicted the distribution of electromagnet...

The thesis concentrates on the numerical analysis of electromagnetic fields with the finite difference method. Simple and fast approximative techniques are studied and developed for the estimation of the electromagnetic properties of various structures. Especially, techniques which preserve the simplicity of a structured lattice are explored. The emphasis in the thesis is put more into the rapi...

Recently there has been much interest in modeling the activity of primate midbrain dopamine neurons as signalling reward prediction error. But since the models are based on temporaldi!erence (TD) learning, they assume an exponential decline with time in the value of delayed reinforcers, an assumption long known to con#ict with animal behavior. We show that a variant of TD learning that tracks v...

This paper describes a full wave approach for analyzing planar interconnect structures, such as power distribution systems in printed circuit boards and multichip modules, using a tightly coupled combination of FDTD and SPICE. The technique enhances the present hybrid full wave circuit methods in terms of robustness and efficiency. The method is applied to a few sample problems to illustrate it...

This paper presents a new whole-body averaged specific absorption rate (SAR) estimation method based on the cylindrical fields scanning technique. The aim of this study is to achieve experimentally an estimation of whole-body averaged SAR in human models due to plane wave exposure using the radiation-field scanning technique. In this paper, the validity of the proposed methods is investigated u...

Folded slots are attractive for active arrays because of their broad bandwidth and simplicity. They have been used recently in a quasi-optical amplifier array. However, little is known about these antennas on thin substrates. The finite-difference time-domain (FDTD) method is applied to the analysis of cpw-fed folded-slot antennas. This paper compares the theoretical results and measured data a...