BACKGROUND Early diagnosis of osteoarthritis (OA) is essential for preventing further cartilage destruction and decreasing severe complications. The aims of this study are to explore the relationship between OA pathological grades and quantitative acoustic parameters and to provide more objective criteria for ultrasonic microscopic evaluation of the OA cartilage. METHODS Articular cartilage s...

Exact reflection and transmission coefficients for supersymmetric shapeinvariant potentials barriers are calculated by an analytical continuation of the asymptotic wave functions obtained via the introduction of new generalized ladder operators. The general form of the wave function is obtained by the use of the F(−∞,+∞)-matrix formalism of Fröman and Fröman which is related to the evolution of...

The study of matrices with a displacement structure is mainly concerned with recursions for the so-called generator matrices. The recursion usually involves free parameters, which can be chosen in several ways so as to simplify the resulting algorithm. In this correspondence we present a choice for the parameters that is motivated by a maximumentropy formulation. This choice further motivates t...

Abst rac t Experimental results of the quantization of Linear Predictive Coded (LPC) coefficients using two general approaches, scalar coefficient quantization and vector quantization, are presented. The LPC coefficients were quantized in several domains: Line Spectral Frequency (LSF), cepstral, predictor, reflection and autocorrelation. Two distortion measures were used to evaluate the quantiz...

This work is concerned with the scattering of a train of progressive waves by a small undulation of the bottom of a laterally unbounded sea, using two-dimensional linear water wave theory. Assuming irrotational motion, a simplified perturbation analysis is employed to obtain the first-order corrections to the velocity potential by using the Green’s integral theorem in a suitable manner, and the...

We formulate and present algorithms and applications for the inverse scattering problem for a one-dimensional layered medium whose reflection coefficients vary with time. We show that given the reflection responses to impulsive plane waves incident on the medium at different times, this problem can be solved either by solving a series of nested non-Toeplitz systems of equations, or by propagati...

Sierra, J.P., Dowding, D.D., Persetto, V., Oliveira, T.A.C., Gironella, X., Mösso, C. and and Mestres, M., 2011. Wave reflection, transmission and spectral changes at permeable low-crested structures. Journal of Coastal Research, SI 64 (Proceedings of the 11th International Coastal Symposium), . Szczecin, Poland, ISSN 0749-0208 Physical model tests were carried out in order to improve the under...

The paper discusses characteristics of a new modeling-based technique for determining dielectric properties of materials. Complex permittivity is found with an optimization algorithm designed to match complex S-parameters obtained from measurements and from 3D FDTD simulation. The method is developed on a two-port (waveguide-type) fixture and deals with complex reflection and transmission chara...

An analytical model for propagation through and reflection from a discontinuity in coupled-cavity waveguides (CCWs) (also known as coupled-resonator optical waveguides—CROW) is developed. The theory is based on a modification of the tight-binding theory for propagation in nonuniform structures. Explicit analytic expressions for the reflection and transmission coefficients are obtained. These ex...