“…Many indicators have been proposed for impulse detection and fault feature extraction from rotating machinery vibration signals. Examples of widely used indicators are kurtosis [1]; the weighted kurtosis index (also known as KCI) [24,29,32,38]; envelope kurtosis (EK) [39]; the Gini index (GI) [40]; and entropy-class indices, such as information entropy (IE, also known as Shannon entropy) [26,34], sample entropy (SE) [35,41], permutation entropy (PE) [15], power spectral entropy (PSE) [42], envelope entropy (EE) [30], and envelope spectrum entropy (ESE) [43]. To verify the superiority of the proposed SDE index, the values of these 10 indices are calculated for the desired modes obtained by VME with different penalty parameters, α n (n = 1, 2, .…”