Nomenclature
NHTSA	National highway traffic safety administration
DDD	Driver drowsiness detection
IoT	Internet of things
KSS	Karolinska sleepiness scale
ML	Machine learning
TP	True positive
TN	True negative
FP	False positive
FN	False negative
NTHUDDD	National Tsuing Hua university drowsy driver detection
PERCLOS	Percentage of eyelid closure
EAR	Eye aspect ratio
SVM	Support vector machine
KNN	K-nearest neighbor
SHRP2	Strategic highway research program results
RF	Random forest
ANN	Artificial neural networks
CNN	Convolutional neural network
FD-NN	Fully designed neural network
TL-VGG16	Transfer learning in VGG16—VG16 is a 16-layers deep CNN architecture, named after the Visual Geometry Group from Oxford
TL-VGG19	Transfer learning in VGG19—VG19 is a 19-layers deep CNN architecture
LSTM	Long short-term memory
RNN	Recursive neural network
ROI	Region of interest
EM-CNN	Eye and mouth CNN
EMD	Empirical mode decomposition
IMF	Intrinsic mode functions
EEG	Electroencephalography
ECG	Electrocardiography
PPG	Photoplethysmography
HRV	Heart rate variability
EOG	Electrooculography
EMG	Electromyography
ELM	Extreme learning machine
SVDD	Simulated virtual driving driver
AVMD	Adaptive variational mode decomposition
RPs	Recurrence plots
RRIs	R–R intervals
Bin-RP	Binary recurrence plot
Cont-RP	Continuous recurrence plot
ReLU-RP	Thresholded recurrence plot
ReLU	Rectified linear unit
HF	High frequency
LF	Low frequency
LF/HF	Low to high frequency
MeanNN	Mean of RRI
SDNN	Standard deviation of RRI
RMSSD	Root means square of the difference of adjacent RRI
TP	Total power which is the variance of RRI
NN50	Number of pairs of adjacent RRI spaced by 50 ms or more
RRV	Respiratory rate variability.
H1	Sum of the logarithmic amplitudes of the bispectrum
H2	Sum of the logarithmic amplitudes of the diagonal elements in the bispectrum
H3	First-order spectral moment of the amplitudes of diagonal elements in the bispectrum
SWA	Steering wheel angle
ANFIS	Adaptive neuro-fuzzy inference systems
MOL	Multilevel ordered logit
BPNN	Back propagation neural network
NIRS	Near-infrared spectroscopy
MEC	Multi-access edge computing