Table 3.
Feature rankings and predictive values for collar and ear data using ReliefF. Colours indicate the feature rank from high (blue) to low (red). A: accelerometer, AD: accelerometer derivative (rate of change), G: gyroscope, GD: gyroscope derivative (rate of change).
| Type | Name | Rank Ear | Rank Collar |
|---|---|---|---|
| A | Dominant Frequency | 1 | 1 |
| AD | Dominant Frequency | 2 | 28 |
| A | Zero Crossings | 3 | 3 |
| GD | Dominant Frequency | 4 | 22 |
| G | Maximum | 5 | 13 |
| G | Zero Crossings | 6 | 11 |
| G | Mean | 7 | 6 |
| G | Signal Area | 8 | 5 |
| GD | Signal Area | 9 | 7 |
| GD | Mean | 10 | 8 |
| G | Spectral Entropy | 11 | 4 |
| GD | Interquartile Range | 12 | 14 |
| G | Dominant Frequency | 13 | 12 |
| GD | Standard Deviation | 14 | 15 |
| AD | Zero Crossings | 15 | 19 |
| A | Minimum | 16 | 2 |
| G | Standard Deviation | 17 | 21 |
| GD | Maximum | 18 | 20 |
| GD | Zero Crossings | 19 | 26 |
| AD | Signal Area | 20 | 9 |
| AD | Mean | 21 | 10 |
| G | Interquartile Range | 22 | 27 |
| GD | Spectral Area | 23 | 32 |
| AD | Interquartile Range | 24 | 18 |
| AD | Spectral Entropy | 25 | 25 |
| A | Spectral Entropy | 26 | 23 |
| G | Spectral Area | 27 | 40 |
| AD | Standard Deviation | 28 | 16 |
| AD | Maximum | 29 | 24 |
| GD | Spectral Entropy | 30 | 31 |
| GD | Kurtosis | 31 | 33 |
| G | Minimum | 32 | 29 |
| A | Interquartile Range | 33 | 17 |
| A | Kurtosis | 34 | 38 |
| A | Standard Deviation | 35 | 30 |
| A | Maximum | 36 | 34 |
| AD | Kurtosis | 37 | 39 |
| A | Mean | 38 | 35 |
| A | Signal Area | 39 | 36 |
| G | Kurtosis | 40 | 37 |
| AD | Spectral Area | 41 | 41 |
| GD | Minimum | 42 | 43 |
| A | Spectral Area | 43 | 42 |
| AD | Minimum | 44 | 44 |