A/D	Analog-to-Digital Converter
AC	Alternating Current Power
AE	Autoencoder
AM-FM	Amplitude Modulation and Frequency Modulation
ANFIS	Adaptive Neuro-Fuzzy Inference System
BLDCM	Brushless Direct Current Motor
CF	Condition Factor
CIs	Condition Indicators
CM	Confusion Matrix
CNNs	Convolutional Neural Networks
COM-CAN	Communication Interface-Controller Area Network Converter
CSV	Comma-Separated Values
DAE	Denoising Auto-Encoder
DAQ	Data Acquisition
DBMs	Deep Boltzmann Machines
DBN	Deep Belief Network
DC	Direct Current Power
DL	Deep Learning
DNN	Deep Neural Network
ELMD	Ensemble Local Mean Decomposition
EO	Energy Operator
FFT	Fast Fourier Transform
FT	Fourier Transform
GKPCA	Greedy Kernel Principal Component Analysis
HDBN	Hybrid Deep Belief Network
IEPE	Integrated Electronics Piezoelectric
k-CDM	K-Step Contrastive Divergence Method
KT	Kurtosis
LSTM	Long Short-Term Memory
MAE	Mean Absolute Error
MHMS	Machine Health Monitoring Systems
NN	Neural Network
P2P	Peak-to-Peak
PCA	Principal Component Analysis
PGB	Planetary Gearboxes
PKFA	Probabilistic Kernel Factor Analysis
RMBs	Restricted Boltzmann Machines
RMS	Root Mean Square
RNNs	Recurrent Neural Networks
SAE	Stacked Auto-Encoder
SAE-DBN	Sparse Autoencoder-Deep Belief Network
SAEs	Sparse Auto-Encoders
SCADA	Supervisory Control and Data
SD	Standard Deviation
SDAs	Stacked Denoising Automatic encoders
SK	Skewness
TSA	Time Synchronous Averaged
WPE	Wavelet Packet Energy