A6airaciThe majority of model-based techniquen proposed to date for solving the multiple source direction-ofarrival (DOA) estimation problem operate under the assumption that the wavefronts impinging on the array are planar. However, when nourcea are located close to the array (i.e., in the near-field), the inherent curvature of the wavefront is no longer negligible. In this paper, we propose t...

In this paper, a new method for automatic sleep stage classification based on time-frequency image (TFI) of electroencephalogram (EEG) signals is proposed. Automatic classification of sleep stages is an important part for diagnosis and treatment of sleep disorders. The smoothed pseudo Wigner-Ville distribution (SPWVD) based time-frequency representation (TFR) of EEG signal has been used to obta...

In this article, a comprehensive study on uncertainty principle of the local polynomial Fourier transform (LPFT) is presented. It shows that the uncertainty product of the LPFT of an arbitrary order is related to the parameters of the signal and the window function, in addition to the errors of estimating the polynomial coefficients. Important factors that affect resolutions of signal represent...

The Wigner function shares several properties with classical distribution functions on phase space, but is not positive-definite. The integral of the Wigner function over a given region of phase space can therefore lie outside the interval [0, 1]. The problem of finding bestpossible upper and lower bounds for a given region is the problem of finding the greatest and least eigenvalues of an asso...

The purpose of this paper is to review the work that has been done in the past years by various researchers in vibration based health and usage monitoring and to identify the principal features and signal-processing algorithm used to this purpose. The damage detection concepts and the signal analysis techniques will be reviewed and categorized. Latest advances in signal processing methodologies...

In this work, a mode identification system for superimposed signals in the same band is presented. More precisely, a signal processing technique, namely the Wigner-Ville distribution, combined with non parametric (k-Nearest Neighbors and Parzen) and Neural Network classifiers is proposed for identifying the transmission modes in an indoor wireless environment. A reconfigurable terminal based on...

The heat capacity Cp of an array of independent aluminum rings has been measured under an external magnetic field ~ H using highly sensitive ac-calorimetry based on a silicon membrane sensor. Each superconducting vortex entrance induces a phase transition and a heat capacity jump and hence Cp oscillates with ~ H . This oscillatory and non-stationary behaviour measured versus the magnetic field ...

This paper serves the idea of applying joint time-frequency representations in electrical engineering. Main directions of researches are concentrated around Cohen’s class of transformation which gives some possibilities of adaptation for analysed signal by choosing appropriate kernel function. Additionally, novel approach delivered by S-transform is also introduced. In order to investigate the ...

In practical Time-Frequency (T-F) analysis of nonstationary signals associated with the use of the Smooth Pseudo Wigner-Ville distribution (SPWV) an important issue is a choice of the smoothing window. To address this problem, a fast sub-optimal technique is proposed, relating the window length to the approximate slope of the frequency modulation. The results obtained by using this automated pr...