Table 1.
Features Used for Activity Recognition
| Description | Total Number of Values |
|---|---|
| Mean, absolute value of the mean | 6 |
| Moments: standard deviation, skew, kurtosis | 9 |
| For the instantaneous change: mean, std dev, skew, kurtosis | 12 |
| Root mean square | 3 |
| Smoothed root mean square (5 pt kernel, 10 pt kernel) | 6 |
| Extremes: min, max, abs min, abs max | 12 |
| Histogram: includes counts for −3 to 3 z-score bins | 21 |
| Fourier components: 8 samples for each axis | 24 |
| Overall mean acceleration | 1 |
| Cross product means, xy, xz, yz | 3 |
| Abs mean of the cross products | 3 |
| Normalized mean cross products | 3 |
| Abs normalized mean cross products | 3 |