CNC	Computerized numerical control
SSAE	Stacked sparse autoencoder
BPNN	Backpropagation neural network
GBDT	Gradient boosting decision tree
PHM	Prognostics health management
SVM	Support vector machine
LSTM	Long-short term memory
ANN	Artificial neural network
SVR	Support vector regression
GPR	Gaussian process regression
AE	Autoencoder
RMSE	Root mean square error
PCA	Principal component analysis
R2	Determination coefficient