Assessment of muscle fatigue involves the creation of indices based on the estimation of variables such as the instantaneous frequency (IF) and the instantaneous amplitude (IA), which can be estimated from a time-frequency (TF) distribution of a surface electromyographic signal (SEMG). Since during muscle fatigue there is a decrease of the IF and an increase of the IA, slopes from these paramet...

Wigner Ville Transform is introduced as a suitable tool for the analysis of the speech signal, as it allows making a correct representation of the signal energy. First, we give a mathematical formulation of the Wigner Ville Transform of a stationary model of voiced speech. The speech model is expressed as a linear combination of the harmonic frequencies of fundamental frequency of the voiced sp...

In this paper we present a very effective method for texture segmentation and analysis using a local spectral method. The idea is to use a modular pattern detection in textured images based on the use of a Pseudo-Wigner Distribution (PWD) followed by a decorrelation procedure that consists of a principal component analyzer (for texture segmentation). The goal is to combine the advantages of a h...

This article demonstrates how time-frequency methods can be used in applications of image processing, such as monitoring, detecting inhomogeneities in textures and texture segmentation. A Pseudo Wigner Distribution (PWD) for 2D images free of aliasing and simultaneously increasing the spatial frequency support is defined through the use of a new analytic signal. In addition to that, cross-terms...

A new member of the Cohen’s class time-frequency distribution is proposed. The kernel function is determined adaptively based on the signal of interest. The kernel preserves the chirp-like components while removing interference terms generated due to the quadratic characteristic of Wigner-Ville distribution. This approach is based on the chirplet as an underlying model of biomedical signals. We...

New generations of spark ignition engines require a correct ignition adjustment to guarantee optimal performance. In this paper, we address the challenge of knock detection improvements with time-frequency analysis. Two real time knock detection methodologies based on the sliding Discrete Fourier Transform and the pseudo Wigner-Ville distribution are exposed. Their relative performances and rob...