It has been shown that detailed information from non-stationary signals such as speech are better represented by an acoustic image, a two dimensional feature representation [10]. Several time frequency representations such as the spectrogram, Wigner-ville and choi-williams distribution have been proposed [6] while the acoustic images based on the two dimensional root cepstrum analysis (TDRC) is...

[1] A comprehensive directional wave buoy data set showing the directional wave spectrum during the passage of a number of hurricanes is presented. The data confirm remote sensing measurements, showing that waves in the forward quadrants of the storm are dominated by swell radiating out from the intense wind regions to the right of the storm centre. The data show that for almost all quadrants o...

two dimensional single frequency scalar vlf data modeling has been studied in this research. vlf method is one of the electromagnetic investigation methods. radio frequency waves are used for investigation of conductive deposits (paal, 1968). synthetic modeling and inversion of single frequency and multiple frequencies of vlf signals was done by oskooi (2004) for two dimensional simple structur...

The purpose of this paper is to review recent research on the applications of existing non-destructive testing (NDT) techniques, especially radio frequency (RF) NDT, for carbon-fibre reinforced plastics (CFRP) composites. Electromagnetic properties of CFRP composites that are associated with RF NDT are discussed first. The anisotropic characteristic of the conductivity and the relationship betw...

The non-Bloch band theory can describe energy bands in a one-dimensional (1D) non-Hermitian system. On the other hand, whether be extended to higher-dimensional systems is nontrivial. In this work, we construct two classes of two-dimensional by reducing problem that for 1D model. these systems, get generalized Brillouin zone complex wave vector and investigate topological properties. model Cher...

Gabor frames for signals over finite Abelian groups, generated by an arbitrary lattice within the finite time-frequency plane, are the central topic of this paper. Our generic approach covers both multi-dimensional signals as well as non-separable lattices, and in fact the multi-window case as well. Our generic approach includes most of the fundamental facts about Gabor expansions of finite sig...

Photonic analogue of topological insulator was recently predicted by arranging ε/μ (permittivity/permeability)-matched bianisotropic metamaterials into two-dimensional superlattices. However, the experimental observation of such photonic topological insulator is challenging as bianisotropic metamaterial is usually highly dispersive, so that the ε/μ-matching condition can only be satisfied in a ...

Abstract An experimental investigation was performed for investigating the tribological performance of micro-dimple surface texture patterns on a cylindrical in realistic operating environment starved lubrication. Micro-dimples were generated by dual-frequency texturing method, which high-frequency (16.3 kHz) three-dimensional (3D) vibration and low-frequency (230 Hz) one-dimensional (1D) appli...

We compute the response matrix for a tracer particle in compressible fluid with odd viscosity living on two-dimensional surface. Unlike incompressible case, we find that an can produce lift force particle. Using "shell localization" formalism, provide analytic expressions drag and forces acting steady state also at finite frequency. Importantly, existence of requires taking into account non-con...