Lying down, preparing food, eating and drinking, socialising, reading, dressing, walking, treadmill walking, vacuuming, wiping tables, running, treadmill, running, cycling, sitting down/getting up, and lying down/getting up
Acceleration sensors
Averaged entropy over 3 axes, main FFT frequency (averaged) over 3 axes, energy of the 0.2 Hz window centred around main frequency over total FFT energy (3-axis average), and averaged mean of cross covariance between every 2 axes
Running, slow walk, fast walk, aerobic dancing, stairs up, and stairs down
Triaxial accelerometer
Mean along -axis, MinMax, STD, and RMS for Am, APF along -axis, -axis, and -axis, VarAPF, STD along -axis, -axis, and -axis, RMS along -axis, -axis, and -axis, correlation between -axis and -axis, and MinMax along -axis, -axis, and -axis
Feature clustering
Multilayer perceptron, SVM, Random Forest, and Logit Boost
Walking, standing, sitting, running, and ascending and descending the stairs
Multiple sensors
Mean, root mean square, standard deviation, variance, mean absolute deviation, cumulative histogram, th percentiles, interquartile range, zero crossing rate, mean crossing rate, and sq. length of ,
Correlation-based Feature Selection (CFS)
Decision trees (C4.5 algorithm), -Nearest Neighbor, Naïve-Bayes, and Bayes Net
Peak frequency of up-down chest acceleration, median of up-down chest acceleration, peak power of up-down chest acceleration, variance of back-forth chest acceleration, sum of variances of 3D wrist acceleration, and power ratio of frequency bands 1–1.5 Hz and 0.2–5 Hz measured from chest magnetometer
124 features: Nike + iPod Packet Payload, magnitude (mean, std. dev., min., max., and min. minus max.), frequency (energy in each of the first 10 frequency components of DFT, energy in each band of 10 frequency components, largest frequency component, and index of the largest frequency component)
Walking, running, cycling, driving, sitting, and standing
Accelerometer
Magnitude, std., mean, min., max., percentiles (10, 25, 50, 75, and 90), and sum and square sum of observations above/below percentile (5, 10, 25, 75, 90, and 95) of magnitude acceleration and square sum of &