the record of human brain neural activities, namely electroencephalogram (eeg), is generally known as a non-stationary and nonlinear signal. in many applications, it is useful to divide the eegs into segments within which the signals can be considered stationary. combination of empirical mode decomposition (emd) and hilbert transform, called hilbert-huang transform (hht), is a new and powerful ...

Optical implementation of a three-dimensional (3-D) Fourier transform is proposed and demonstrated. A spatial 3-D object, as seen from the paraxial zone, is transformed to the 3-D spatial frequency space. Based on the new procedure, a 3-D joint transform correlator is described that is capable of recognizing targets in the 3-D space.

A generalized S transform based on energy normalized windows is presented, which avoids the weighting effect of existing S transform influenced by the time-frequency spectral energy. The transform can reflect the spectral energy distribution of different frequency components while maintaining the excellent time-frequency resolution. While TT transform is a new approach to process non-stationary...

Active or passive movement causes a temporary reduction in muscle stiffness that gradually returns to baseline levels when the muscle remains still. This effect, termed muscle thixotropy, alters the mechanical properties of the joint around which the muscle acts, reducing its resonant frequency. Because physiological tremor is affected by joint mechanics, this suggests that prior movement may a...

We present a theor of linear and quadratic time-frequency representations (&FRs) that are covariant to time-frequency displacement operators. The theory unifies important T F R classes (short-time Fourier transform, wavelet transform; Cohen’s, affine, hyperbolic, and power classes), and it allows the systematic construction of new TFRs that are covariant to a given operator.

variation of frequency and voltage by load changes in a microgrid is a challenge in droop control method. centralized restoration frequency or voltage in a microgrid requires communication link and therefore affects the advantage of decentralized droop control such as reliability, simplicity and inexpensiveness. this paper proposes a decentralized method that restores the frequency of a microgr...

Energy concentration of the S-transform in the time-frequency domain has been addressed in this paper by optimizing the width of the window function used. A new scheme is developed and referred to as a window width optimized S-transform. Two optimization schemes have been proposed, one for a constant window width, the other for time-varying window width. The former is intended for signals with ...