Multiscale Bidirectional Input Convolutional and Deep Neural Network for Human Activity Recognition

Table 4

Calculation of time and frequency domain features.

Feature	Calculation formula	Meaning
Mean		The mean of the activity segment data
Variance		The variance of activity segment data
Standard deviation		The standard deviation of the activity segment data
Skewness		The skewness of the activity segment data
Quartile deviation		The difference between the third quartile and the first quartile
Power spectral density	This is the Fourier transform formula	Power in unit frequency band
Median frequency		Median of power spectral density
Average frequency		Mean value of power spectral density
Energy spectral density		Signal energy in unit frequency band