In this paper we present a new methodology for computing a time-frequency map for non-stationary signals using the continuous wavelet transform (CWT). The conventional method of producing a time-frequency map using the Short Time Fourier Transform (STFT) limits the time-frequency resolution by a pre-defined window length. In contrast, the CWT method does not require pre-selecting a window lengt...

The relationship between finite discrete Zak transform and finite Gabor expansion are well discussed in this paper. In this paper, we present two DFT-based algorithms for computing Gabor coefficients. One is based upon the time-split Zak transform, the other is based upon the frequency-split Zak transform. These two methods are time and frequency dual pairs. With the help of Zak transform, the ...

Due to the periodical motions of most machinery in steady state operation, many diagnosis techniques are based on frequency analysis. This is often performed through Fourier transform. Some extensions of these techniques to the more general case of non stationary operation have been proposed. They are based on signal processing advances such as time-frequency representations and adaptive filter...

 The identification of the timing of the discharges of groups of muscle fibers (motor units) is of utmost importance in research into the strategies employed by the central nervous system in producing muscle force and in the diagnosis of neuromuscular diseases. The process involves the recognition of unique shapes (action potentials) contributed by different motor units at random times through...

It is shown how the Zak transform can be used to find nontrivial examples of functions f, g E L 2 ( 2 ) with f . g = 0 = F . C, where F, G are the Fourier transforms of f, g, respectively. This is then used to exhibit a nontrivial pair of functions h, keL2(T1), h # k, such that I h I = 1 k 1 , I H I = I K 1 . A similar construction is used to find an abundance of nontrivial pairs of functions h...

In this paper a new time-frequency interference terms cancellation method will be presented. We will consider this problem in the multi-structure signal case, where this problem is often difficult to solve due to interference geometry, which can be superposed on the signal component. We propose a technique based on the atomic decomposition of the signal, in order to extract its components. A py...

Wide band digital audio signals have a very high data-rate associated with them due to their complex nature and demand for highquality reproduction. Although recent technological advancements have significantly reduced the cost of bandwidth and miniaturized storage facilities, the rapid increase in the volume of digital audio content constantly compels the need for better compression algorithms...

It is shown how the Zak transform can be used to find nontrivial examples of functions f, g E L 2 ( 2 ) with f . g = 0 = F . C, where F, G are the Fourier transforms of f, g, respectively. This is then used to exhibit a nontrivial pair of functions h, keL2(T1), h # k, such that I h I = 1 k 1 , I H I = I K 1 . A similar construction is used to find an abundance of nontrivial pairs of functions h...

We examined whether the nonlinear control mechanism of the fetal autonomic nervous system would change in various fetal states. Eight thousand or more fetal heartbeats were detected from normal, hypoxemic, and acidemic fetuses. Fetal heart Doppler-signal intervals were determined in a high-precision autocorrelation method, and a time series of fetal heart rate fluctuation was obtained. The dist...

An approach for processing sonar signals with the ultimate goal of ocean bottom sediment classification and underwater buried target classification is presented in this paper. Work reported for sediment classification is based on sonar data collected by one of the AN/AQS-20’s sonars. Synthetic data, simulating data acquired by parametric sonar, is employed for target classification. The techniq...