ANFIS	Adaptive neuro-fuzzy inference system
ApEn	Approximate entropy
CFBEE	Characteristic frequency band energy entropy
CMSPE	Composite multi-scale permutation entropy
CMSWPE	Composite multi-scale weighted permutation entropy
CWC	Continuous wavelet coefficients
CWRU	Case Western Reserve University
DE	Dispersion entropy
EE	Energy entropy
EEMD	Ensemble empirical mode decomposition
ELM	Extreme learning machine
EMD	Empirical mode decomposition
EWT	Empirical wavelet transform
FAWT	Flexible analytical wavelet transform
GCMSFE	Generalized composite multi-scale fuzzy entropy
GCMSPE	Generalized composite multi-scale permutation entropy
GRCMSE	Generalized refined composite multi-scale sample entropy
GCMSSDE	Generalized composite multi-scale symbol dynamic entropy
GCMSWPE	Generalized composite multi-scale weighted permutation entropy
GRCMSSE	Generalized refined composite multiscale sample entropy
GWO	Grey wolf optimizer
HSDE	Hierarchical symbolic dynamic entropy
HDE	Hierarchical dispersion entropy
HSE	Hierarchical sample entropy
HPE	Hierarchical permutation entropy
IEE	Improved energy entropy
IEMD	Improved empirical mode decomposition
IMSDE	Improved multi-scale dispersion entropy
IMSPE	Improved multi-scale permutation entropy
IR	Inner race
ISSD	Improved singular spectrum decomposition
IMS	Intelligence maintenance systems
LDA	Linear discriminant analysis
MBSE	Multi-band spectrum entropy
MHSE	Marginal Hilbert spectrum entropy
MLP	Multi-layer perceptron
WSST	Wavelet semi-soft threshold
MPA	Marine predators algorithm
MSE	Multi-scale entropy
MSDE	Multi-scale dispersion entropy
MSFDE	Multi-scale fluctuation-based dispersion entropy
MSFE	Multi-scale fuzzy entropy
MSSFE	Multi-scale symbolic fuzzy entropy
MMSFDE	Multivariable multi-scale fuzzy distribution entropy
MSPE	Multi-scale permutation entropy
MSSE	Multi-scale sample entropy
MSSDE	Multi-scale symbolic dynamic entropy
MSRCSDFE	Multi-scale refined composite standard deviation fuzzy entropy
MHMSFDE	Multivariable hierarchical multi-scale fluctuation dispersion entropy
mRMR	Max-relevance min-redundancy
OR	Outer race
PCA	Principal component analysis
PE	Permutation entropy
PGB	Planetary gearboxes
PSO	Particle swarm optimization
PNN	Probabilistic neural network
RCFOA	Reverse cognitive fruit fly optimization algorithm
RCMSAE	Refined composite multi-scale approximate entropy
RCMSDE	Refined composite multi-scale dispersion entropy
RCMSFE	Refined composite multi-scale fuzzy entropy
RF	Random forest
SFE	Symbolic fuzzy entropy
SVM	Support vector machine
SWD	Swarm decomposition
SMCMSDE	Stacking modified composite multi-scale dispersion entropy
t-SNE	t-distributed stochastic neighbor embedding
TSMSWPE	Time-shift multi-scale weighted permutation entropy
TSMSDE	Time-shift multi-scale dispersion entropy
VPMCD	Variable predictive models based discrimination
WMSFDE	Weighted multi-scale fluctuation-based dispersion entropy
WRCMSDE	Weighted refined composite multi-scale dispersion entropy
WRCMSDE	Weighted refined composite multi-scale dispersion entropy
WRCMSFE	Weighted refined composite multi-scale fuzzy entropy
WRCMSPE	Weighted refined composite multi-scale permutation entropy