While speaker identification performance has improved dramatically over the past years, the presence of interfering noise and the variety of channel conditions pose a major obstacle. Particularly the mismatch between training and test condition leads to severe performance degradations. In this paper we explored several approaches to compensation for the effects of reverberation including compen...

Given far field data of a time-harmonic wave radiated by an ensemble of well separated acoustic or electromagnetic sources as well as a priori information on the locations of these sources, we discuss an algorithm to approximate the far field data radiated by each of these sources separately. The method is based on a Galerkin procedure considering subspaces spanned by the singular vectors of “r...

The limited resolution of a conventional optical imaging system stems from the fact that the fine feature information of an object is carried by evanescent waves, which exponentially decays in space and thus cannot reach the imaging plane. We introduce here an adiabatic lens, which utilizes a geometrically conformal surface to mediate the interference of slowly decompressed electromagnetic wave...

By use of approximations based on physical reasoning radar cross-section results for bodies of revolution are found. In the Rayleigh region (wavelength large with respect to object dimensions) approximate solutions are found. Examples given include a finite cone, a lens, an ellipticogive,.a spindle and a finite cylinder. In the physical optics region (wavelength very small with respect to all r...

The far-field reflector problem is a well-known inverse problem arising in geometric optics. It consists in creating a mirror that reflects a given point light source to a prescribed target light at infinity. In this article, we study this problem under the common design constraint that the mirror is convex and is the graph of a polynomial over a given plane. We propose a method that iterativel...

Inhomogeneous media identification is the problem of determining the physical properties of an unknown inhomogeneity from its response to various interrogating modalities. This response, recorded in measured data, comes as a result of the interaction of the inhomogeneity with an exciting physical field. Inhomogeneous media identification is mathematically modeled as the problem of determining t...