Table 1.

The list of acronyms.

Acronym	Full Name
VMD	variational mode decomposition
IMF	intrinsic mode function
SKE	spectral kurtosis entropy
ELM	extreme learning machine
SaE-ELM	self-adaptive evolutionary extreme learning machine
WELM	weighted extreme learning machine
WSaE-ELM	weighted self-adaptive evolutionary extreme learning machine
BW	bandwidth
FK	spectral kurtosis
CF	center frequency
FT	Fourier transform
SNR	signal-to-noise ratio
RMSE	root mean squared error