A Novel Cuckoo Search Optimized Deep Auto-Encoder Network-Based Fault Diagnosis Method for Rolling Bearing

Table 3

The formula of the partial extracted features.

Statistical features in time domain
Skewness index		Kurtosis value		Peak value index
Margin index		Waveform index		Pulse index
Note: ,
Statistical features in frequency domain
Center of gravity frequency		Frequency standard deviation
Root mean square frequency,
Skewness frequency		Kurtosis frequency
Note: is the power spectral density, ,