At present, in the feature extraction of non-stationary vibration signals, many timefrequency analytic methods have emerged to meet the further need of non-stationary signal analysis such as Wavelet Transform (WT), Short Time Fourier Transform (STFT), WignerVille Distribution (WVD), Empirical Mode Decomposition (EMD), Ensemble Empirical Mode Decomposition (EEMD) and so on. However, these time-f...

This paper introduces the technique of Prior Subspace Analysis (PSA) as an alternative to Independent Subspace Analysis (ISA) in cases where prior knowledge about the sources to be separated is available. The use of prior knowledge overcomes some of the problems associated with ISA, in particular the problem of estimating the amount of information required for separation. This results in improv...

This study proposes the application of different linear and quadratic Time-Frequency Representations (TFR) for the analysis of Ventricular Late Potentials (VLP) in High-Resolution Electrocardiographic (HRECG) records. The TFR used here were Short-Time Fourier Transform (STFT), Wigner-Ville (WV) and Choi-Williams (CW) distributions. These techniques were used to evaluate the risk of Ventricular ...

A hierarchical system for audio classi cation and retrieval based on audio content analysis is presented in this paper. The system consists of three stages. The rst stage is called the coarse-level audio classi cation and segmentation, where audio recordings are classi ed and segmented into speech, music, several types of environmental sounds, and silence, based on morphological and statistical...

This simple NDT method uses impact pulse as a simple wide-spectrum excitation for spectral analysis. Usually the frequencies of resonance components from impact-echo (I-E) signal are compared with standard forms and their deviations signalize non-ideality and defects. This NDT method is very cheap and effective especially for small bodies with expressive resonance properties, but it has a small...

Starting from the context of finite dimensional signal spaces, as it can be constructively realized on a computer and completely described in terms of concepts from linear algebra, we describe first the algebraic side of this problem. The second part of the material emphasizes the necessary definitions and problems (e.g., the form of convergence of various infinite series occurring during the d...

The proportional-bandwidth and constant-bandwidth timefrequency signal decompositions of the wavelet, Gabor, and Wilson Manuscript received August 21, 1992; revised May 26, 1993. The Guest Editor coordinating the review of this paper and approving it for publication was Dr. Patrick Flandrin. This work was supported in part by the Sound Group of the computer-based Education Research Laboratory, ...

The choice of demodulation band for envelope analysis of faulty bearings is often made by spectrum comparison with a healthy bearing, to choose resonance frequencies where the largest change occurred as a result of the fault. It has recently been established that the so-called “spectral kurtosis” gives a very similar indication of the band to be demodulated without requiring historical data. Th...

Air-borne acoustic based condition monitoring is a promising technique because of its intrusive nature and the rich information contained within the acoustic signals including all sources. However, the back ground noise contamination, interferences and the number of Internal Combustion Engine ICE vibro-acoustic sources preclude the extraction of condition information using this technique. There...

In this paper, a combustion analysis of a compression ignition (CI) engine operating with biodiesel blends has been experimentally investigated to examine the effects of biodiesel on the combustion process and the characteristics of the engine noise produced by the combustion process. The experiment with different loads and speeds was conducted on a four-cylinder, four-stroke, direct injection ...