Table 1.

Statistical and frequency-domain features.

Signal	Time Domain	Frequency Domain
Acceleration (3 channels)	Root mean squared	Dominant frequency
	Variance	Power at dominant frequency
	Kurtosis
	Skewness
	Linear Correlation (x-y, x-z, y-z)
Angular velocity (3 channels)	Root mean squared	Dominant frequency
	Variance	Power at dominant frequency
	Kurtosis
	Skewness
	Linear Correlation (x-y, x-z, y-z)