Equation 1 is used to create a synthetic signal y
with sampling frequency of 8 kHz: (a) Signal y
, ( α,σ,μ,a ) for each component from 1 to 7 is as following: (6,0.001,0.42,2Π3600), (1,0.05,0.68,2Π2600), (1,0.05,0.68,2Π600), (6,0.001,0.80,2Π1700), (1,0.04,0.93,2Π1000), (1,0.03,1.18,2Π2600), (6,0.001,1.27,2Π1700). (b) Signal y2is generated by replacing the 5th and 6th components of signal y1with two chirps with slopes of 1 and 0.5 kHz/s, respectively. (c) TFD of y1. (d) TFD of y2. (e) TF feature plane including the feature points. Although NMF of order 10 was applied to TF decomposition of each signal, 3 of the y1decompositions () did not have any significant content () so they were excluded from the analysis. Dy 1and Dy 2were the clusters identified as the discriminant features in each signal. (f, g) The TFD structures selected as the discriminant patterns in y1and y2, respectively.