Visualization is an intuitive way to observe and analyse the phenomena related to the propagation of sound. It is evident that human hearing is highly capable of discriminating different aspects from an acoustic signal. The ability to discriminate is not necessarily enough to identify causality, that is answering the question: what aspect in the audio signal path, being a device or a room, cont...

In this paper we investigate the properties of two-dimensional photonic crystals (2D PhCs) with both hexagonal and square symmetry for applications in optoelectronics and telecommunication. An efficient way of manipulating the light is to make use of the defects introduced within the periodic structure, which consequently break the symmetry of the crystal, resulting in linear waveguides or reso...

We consider the finite element approximation of the solution to a singularly perturbed second order differential equation with a constant delay. The boundary value problem can be cast as a singularly perturbed transmission problem, whose solution may be decomposed into a smooth part, a boundary layer part, an interior/interface layer part and a remainder. Upon discussing the regularity of each ...

SUMMARY The Finite-Difference Time-Domain (FDTD) technique is presented in this paper as an estimation method for radio propagation prediction in large and complex wireless local area network (WLAN) environments. Its validity is shown by comparing measurements and Ray-trace method with FDTD data. The 2GHz (802.lIb/g) and 5GHz (802.lIa) frequency bands are used in both the calculations and exper...

and Applied Analysis 3 exists, when σ t t here by s → t it is understood that s approaches t in the time scale and when x is continuous at t and σ t > t, xΔ t : x σ t − x t μ t . 1.7 Note that if T R, then the delta derivative is just the standard derivative, and when T Z the delta derivative is just the forward difference operator. Hence, our results contain the discrete and continuous cases a...

In this paper, a numerical solution of time fractional advection-dispersion equations are presented.The new implicit nite dierence methods for solving these equations are studied. We examinepractical numerical methods to solve a class of initial-boundary value fractional partial dierentialequations with variable coecients on a nite domain. Stability, consistency, and (therefore) convergenceof t...

Fractional order diffusion equations are generalizations of classical diffusion equations which are used to model in physics, finance, engineering, etc. In this paper we present an implicit difference approximation by using the alternating directions implicit (ADI) approach to solve the two-dimensional space-time fractional diffusion equation (2DSTFDE) on a finite domain. Consistency, unconditi...

The scope of this paper is the time domain simulation of the sound field radiated by a string. Different time domain methods have been successfully implemented for string simulations. These methods not only perform realtime string sound synthesis, but also pressure and particle velocity generated around strings can be obtained. It is very useful to analyze the sound field interaction with exter...