The Green’s function (GF) directly eases the efficient computation for acoustic radiation problems in shallow water with use of Helmholtz integral equation. difficulty solving GF lies need to consider boundary effects. In this paper, a rigorous theoretical model interactions between spherical wave and liquid is established by Fourier transform. accurate adaptive Pekeris waveguide lossy seabed d...

AR = cavity aspect ratio a = speed of sound b = cavity half-width ~ C = dynamic compressibility c = phase speed cp = specific heat at constant pressure f = frequency H = cavity depth k = wave number m = propagation constant P = pressure Pr = Prandtl number R = reflection coefficient p = acoustic pressure pi = initial pulse amplitude Re = acoustic Reynolds number s = cavity spacing T = temperatu...

Scientific objective of this research is to understand acoustic wave propagation in a dynamic environment in two different frequency bands: (a) Low frequency band (50 Hz to 500 Hz). The subject of interest in this band is to assess the effect of environment anisotropy on acoustic wave propagation, with an emphasis on the separation of different effects due to horizontal refraction and mode coup...

For a GNSS receiver’s robustness against RFI and the high accuracy of navigation solution in GNSS, interference source detection and mitigation are needed. In this paper, an adaptive lattice IIR notch filter is employed to track single-tone continuous wave and swept continuous wave interference signals, and an interference detection method is proposed. Furthermore, this paper presents interfere...

from the early 1950s, estimating the autocorrelations of polynomials with coefficients on the unit circle has found applications in ising spin systems and in surface acoustic wave designs. in this paper, a technique is introduced that not only estimates the autocorrelations, but for some special types of such polynomials, it locates the frequencies at which maximum autocorrelation occurs.

We demonstrate that the tunable potential introduced by a surface acoustic wave on a homogeneous polariton condensate leads to fragmentation of the condensate into an array of wires which move with the acoustic velocity. Reduction of the spatial coherence of the condensate emission along the surface acoustic wave direction is attributed to the suppression of coupling between the spatially modul...

Four thin-film adhesion characterization methods are proposed. Two of them are surface acoustic wave based and the two others emphasize the complementary nature between acoustic microscopy, scratch test and tensile experiments. A continuous wave scanning acoustic microscope was used to propagate surface modes in the specimen and to measure the surface acoustic wave velocity as a function of the...

Oscillatory behavior is one of the basic properties of the solar surface. Stochastic wave excitation in the turbulent convective medium and frequent interference of acoustic wavefronts make the problem of understanding of the mechanism of solar oscillations very complicated. In observational data individual wave excitation events overlap with other wave events. Nevertheless, individual impulsiv...