Contradirectional propagation through active, first-order, almost-periodic, corrugated waveguide gratings is analyzed by using both coupled-mode theory and a combined effective-index/impedance-matching matrix technique. For TE-mode operation, which is near the first-order Bragg wavelength, the equivalence of the two techniques is analytically demonstrated for shallow surface corrugations.

Abstract The classical Transfer-Matrix Method (TMM) is often used to calculate the input impedance of woodwind instruments. However, the TMM ignores the possible influence of the radiated sound from toneholes on other open holes. In this paper a method is proposed to account for external tonehole interactions. We describe the Transfer-Matrix Method with external Interaction (TMMI) and then comp...

“Geomagnetically induced currents” (GIC) in ground-based technological networks are a manifestation of space weather. GIC are a potential source of problems to the systems and therefore important in practice. GIC in a power system (or in principle in any other discretely-earthed system) can be calculated conveniently by using matrix equations presented earlier. Since temporal variations associa...

A generalised method for the identification of the parameters which describe the dynamic properties of media between coupled substructures using measured FRFs is presented in this paper. The effort is mainly focused on the development of this generalised method and the improvement of its constituent algorithms. The method presented here is more general and more practical in some aspects when co...

This paper provides a mathematical analysis of the linearized inverse problem in multifrequency electrical impedance tomography. We consider the isotropic conductivity distribution with a finite number of unknown inclusions with different frequency dependence, as is often seen in biological tissues. We discuss reconstruction methods for both fully known and partially known spectral profiles, an...

Objectives: In the present investigation, transparent novel glass embedded with ferroic matrix was prepared by melt-quenching method. Among all glasses, selective ceramic is also prepared. Optical and electrical measurements were carried out on samples. Methods: We have composition of (100-x)[0.55Bi2O3-0.30B2O3-0.15TiO2] +xBaTiO3 ; x=0, 10, 20, 30, 40, 50 wt.%. Appropriate amounts reactant mixt...

The present work deals with a generalized algorithm for analyzing a network of linear passive acoustic filters having multi-port elements which are interconnected to each other in an arbitrary manner through their respective ports or through general 2-port elements. A multi-port element is characterized by an impedance [Z] matrix, and the junctions through which these multi-port elements are co...

Adaptive multiscale moment method (AMMM) is presented for the analysis of scattering from three-dimensional (3-D) perfectly conducting bodies. This algorithm employs the conventional moment method (MM) using the subsectional triangular patch basis functions and a special matrix transformation, which is derived from solving the Fredholm equation of the first kind by the multiscale technique. Thi...