Vibration problems in rotors can be extremely frustrating and may lead to greatly reduced reliability. By utilizing the proper data collection and analysis techniques, the faults because of vibration can be discovered and predicted. The signal analysis is important in extracting fault characteristics in fault diagnosis of machinery. The traditional signal analysis can not settle for non-station...

We present an efficient method for robustly calculating time-frequency attributes of a signal, including instantaneous mean frequency, bandwidth, and kurtosis. Most current approaches involve a costly intermediate step of computing a (highly oversampled) 2-d bilinear time-frequency representation (TFR), which is then collapsed to the I-d attribute. Using the principles of hybrid linearhilinear ...

The Modal distribution is a time-frequency distribution specifically designed to model the quasi-harmonic, multi-sinusoidal, nature of music signals and belongs to the Cohen general class of time-frequency distributions. A streaming, object-oriented implementation of the Modal distribution is presented which forms the basis for designing other members of the Cohen class. Implementation of this ...

The most popular time-frequency analysis tool, the Short-Time Fourier Transform, suffers from blurry harmonic representation when voiced speech undergoes changes in pitch. These relatively fast variations lead to inconsistent bins in frequency domain and cannot be accurately described by the Fourier analysis with high resolution both in time and frequency. In this paper a new analysis tool, cal...

We study local deformations of time-frequency and timescale representations, in the framework of the so-called reassignment methods, which aim at deblurringg time-frequency representations. We focus on deformations generated by appropriate vector elds deened on time-frequency or time scale plane, and constructed on the basis of geometric and group-theoretical arguments. Such vector elds may be ...

the performance of nanoscale field effect diodes as a function of the spacer length between two gates is investigated. our numerical results show that the ion/ioff ratio which is a significant parameter in digital application can be varied from 101 to 104 for s-fed as the spacer length between two gates increases whereas this ratio is approximately constant for m-fed. the high-frequency perform...

Current multimedia technologies call for efficient ways of representing signals. We review several efficient methods for signal representation, emphasizing potential applications in signal compression and denoising. We pay special attention to the representations which are adapted to “non-stationary” features of signals, in particular the classes of bilinear representations, and their approxima...

and the corresponding inversion formula analyze the frequency content of f . Underlying many finer decompositions into simpler pieces are the fundamental invariance properties of R and the corresponding operators. For harmonic analysis on R these are the translations t → t+x and the dilations t → at, where t, x ∈ R and a ∈ R. The corresponding operators are the translation operator Tx (2) Txf(t...