Time–frequency analysis of the dynamics of different wake vorticity structures, generated from a triangular prism orientated with its apex edge against the incoming wind, is carried out. Time–frequency analysis of time-series obtained with hot-wire anemometry is performed through a procedure based on proper orthogonal decomposition and spectral components are extracted with a technique that pro...

Analysis of linear time-varying (LTV) systems is closely related to time-varying spectral analysis of nonstationary processes. In this paper, we link together the classical theory of linear time-varying systems and wellknown concepts from time-varying spectral analysis. Formulation of the generalized Weyl correspondence provides a unified time-frequency (TF) framework for linear system analysis...

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...

Motivated by the limitation of analyzing oscillatory signals composed of multiple compo-nents with fast-varying instantaneous frequency, we approach the time-frequency analysisproblem by optimization. Based on the proposed adaptive harmonic model, the time-frequency representation of a signal is obtained by directly minimizing a functional, whichinvolves few properties an “ideal...

spectral decomposition is a powerful tool for analysis of seismic data. fourier transform determines the frequency contents of a signal. but for analysis of non-stationary signals, 1-d transform to frequency domain is not sufficient. in early years, transforming of seismic traces into time and frequency domain was done via windowed fourier transform, called a short time fourier transform (stft)...

We present a method for estimating the instantaneous frequency of a signal. This method involves the calculation of a time–frequency energy density of the signal, then obtaining an instantaneous frequency estimate from this joint density. Time–frequency energy density is calculated as a least squares optimal combination of multi–window Gabor based evolutionary spectra. The optimal weights are o...