Applications of fractional lower order S transform time frequency filtering algorithm to machine fault diagnosis.

Stockwell transform(ST) time-frequency representation(ST-TFR) is a time frequency analysis method which combines short time Fourier transform with wavelet transform, and ST time frequency filtering(ST-TFF) method which takes advantage of time-frequency localized spectra can separate the signals from Gaussian noise. The ST-TFR and ST-TFF methods are used to analyze the fault signals, which is reasonable and effective in general Gaussian noise cases. However, it is proved that the mechanical bearing fault signal belongs to Alpha(α) stable distribution process(1 < α < 2) in this paper, even the noise also is α stable distribution in some special cases.

[Evoked Potential Blind Extraction Based on Fractional Lower Order Spatial Time-Frequency Matrix].

The impulsive electroencephalograph (EEG) noises in evoked potential (EP) signals is very strong, usually with a heavy tail and infinite variance characteristics like the acceleration noise impact, hypoxia and etc., as shown in other special tests. The noises can be described by a stable distribution model.

[Blind estimation of evoked potentials based on covariations in non-gaussian noise].

Evoked potentials (EPs) have been widely used to quantify neurological system properties. Traditional EP analysis has been developed under the condition that the background noises in EP are Gaussian distributed. Recently some researches indicate that electroencephalogram (EEG) is non-guassian in some especial conditions.

[Estimation of evoked potentials based on MD criterion and Givens matrix in non-Gaussian noise environments].

Traditional EP analysis is developed under the condition that the background noises in EP are Gaussian distributed. Alpha stable distribution, a generalization of Gaussian, is better for modeling impulsive noises than Gaussian distribution in biomedical signal processing. Conventional blind separation and estimation method of evoked potentials is based on second order statistics (SOS).

Blind estimation of evoked potentials in alpha stable distribution environments.

Evoked potentials (EPs) have been widely used to quantify neurological system properties. Traditional EP analyses are developed under the condition that the background noise in EP analysis are Gaussian distributed. Alpha stable distribution, a generalization of Gaussian, is better for modeling impulsive noise than Gaussian distribution in biomedical signal processing.