In this paper, A flexibility-based method for damage identification of cantilever-type structures is proposed. Using the linear relation between flexibility matrix element and structure parameter, the damage equation involving modal parameter and damage coefficient of each structure element is established firstly. Then, using the free vibration response signal of structure and the time-frequenc...

The time-frequency (TF) version of the wavelet transform and the “affine” quadraticlbilinear TF representations can be used for a TF analysis with constant-Q characteristic. This paper considers a new approach to constant-Q TF analysis. A specific TF warping transform is applied to Cohen’s class of quadratic TF representations, which results in a new class of quadratic TF representations with c...

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A virtual instrument for time–frequency analysis is presented. Its realization is based on an order recursive approach to the time–frequency signal analysis. Starting from the short time Fourier transform and using the S-method, a distribution having the auto-terms concentrated as high as in the Wigner distribution, without cross-terms, may be obtained. The same relation is used in a recursive ...

Efficient measurement of time-frequency distributions (TFDs) concentration can provide a quantitative criterion for evaluation of various distributions performance. It can be used for adaptive and automatic parameter selection in time-frequency analysis, without supervision of a user. Measures for distribution concentration of monocomponent signals date back to [3], [8]. For more complex signal...

S-transform is a new time-frequency analysis method, which is deduced from short-time Fourier transform and continue Wavelet transform. It has much better performance than traditional time-frequency method. Therefore, in this paper, the basic principle of is briefly introduced and the relationships between is analyzed by theoretical derivation. According to the simulation experiments, the time-...

We give a new characterization of the Gelfand triple of function spaces in (S0, L, S′ 0) by means of a family of time-frequency localization operators. The localization operators are defined by the short-time Fourier transform and determine the local time-frequency behavior, whereas the global timefrequency distribution is characterized by a sequence space norm. We also show that the alternativ...