In this paper, we consider scattering by a guided wave incident obliquely on a surface breaking crack in a laminated composite plate, with a view to ultrasonic nondestructive assessment of cracks. The solution to this problem is the first step towards analyzing the general three-dimensional scattering problem. The method used for modeling is a hybrid method which combines finite element method ...

A theoretical model is developed for the interaction of intense femtosecond laser pulses with solid targets on the basis of the two-temperature equation of state for an irradiated substance. It allows the description of the dynamics of the plasma formation and expansion. Comparison of available experimental data on the amplitude and phase of the complex reflection coefficient of aluminum with t...

The small perturbation method (SPM) is applied to study thermal emission from a layered medium bounded by a slightly rough interface. Brightness temperatures are calculated to second order in surface height, including both specular reflection coefficient corrections and incoherent Bragg scatter terms. Unlike the homogeneous medium case, in which the SPM applied for emission predictions produces...

This thesis is concerned with the extension of the theory and computational techniques of time-series linear prediction to two-dimensional (2-D) random processes. 2-D random processes are encountered in image processing, array processing, and generally wherever data is spatially dependent. The fundamental problem of linear prediction is to determine a causal and causally invertible (minimumphas...

Backscatter communication (BackCom), which allows a backscatter node (BN) to communicate with the reader by modulating and reflecting the incident continuous wave from the reader, is considered as a promising solution to power the future Internet-of-Things. In this paper, we consider a single BackCom system, where multiple BNs are served by a reader. We propose to use the power-domain non-ortho...

Here Γ is the gamma function and the function r is the so-called reflection coefficient for the potential q0(x) = q(x, t = 0), as described below. The error term O( log t t ) is uniform for all x ∈ R. The above asymptotic form was first obtained in [ZaMa], but without the error estimate. Based on the nonlinear steepest descent method introduced in [DZ1], the error estimate in (1.1) was derived ...

Introduction The nondestructive, in-situ testing of early-age concrete properties is a crucial point for the progress of many construction projects in the building sector. The application of such techniques can establish e.g. the earliest possible form removal from concrete construction elements, thereby opening highways to traffic or releasing prestress from steel reinforcement with greatest e...

Using Biot's theory, a set of boundary conditions is presented for wave transmission and reflection at the contact surface between an elastic medium (fluid or solid) and a fluid-saturated porous solid (Biot medium). The analysis shows the continuity of the normal component of the density energy flux vectors across the contact surfaces, so that total energy is preserved. Energy reflection and tr...

We analyze the reflection and transmission coefficients calculated from transfer matrix simulations on finite lengths of electromagnetic metamaterials, to determine the effective permittivity ~«! and permeability ~m!. We perform this analysis on structures composed of periodic arrangements of wires, split ring resonators ~SRRs!, and both wires and SRRs. We find the recovered frequency-dependent...

We investigate the scattering of phase oscillation of Bose-Einstein Condensate by a ’draining of bathtub’ type fluid motion. We derive a relation between the reflection and transmission coefficients which exhibits existence of analog of ’Superradiance effect’ in BEC vortex with sink.