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Machine learning parameter settings for the models used in this study
| Model | Parameter | Setting value |
|---|---|---|
| LSVR [11] | Epsilon | 0.0 |
| Tol | 0.0001 | |
| C | 1.0 | |
| Loss | epsilon_insensitive | |
| DTR [11] | intercept_scaling | 1.0 |
| max_iter | 100,000 | |
| max_depth | None | |
| min_samples_split | 2 | |
| min_samples_leaf | 1 | |
| min_weight_fraction_leaf | 0.0 | |
| XGBR | max_leaf_nodes | None |
| min_impurity_decrease | 0.0 | |
| learnig_rate | 0.3 | |
| Subsample | 1 | |
| n_estimators | 100 | |
| Gamma | 0.0 | |
| max_depth | 6 | |
| min_child_weight | 1 | |
| max_delta_step | 0 | |
| num_leaves | 31 | |
| max_depth | −1 (no limit) | |
| Subsample | 1 | |
| LGBMR | learning_rate | 0.1 |
| n_estimators | 100 | |
| min_split_gain | 0.0 | |
| min_child_weight | 0.001 | |
| min_child_samples | 20 | |
Relative predictive performance of the CMJ flight time variable, measured using MAPE
| Integration-based method | LGBMR | |
|---|---|---|
| CMJ | 11.75 | 2.04 |
Data features used to predict values for the seven CMJ performance variables
| Feature | Peak force | Second peak force | Flight time | Average loading rate | Net impulse | Peak power | RFD |
|---|---|---|---|---|---|---|---|
| Mean | V | V | V | V | V | V | |
| SD | V | V | V | V | V | V | |
| IQR | V | V | V | V | V | V | V |
| Skewness | V | V | V | V | V | V | V |
| Kurtosis | V | V | V | V | |||
| Frequency | V | V | V | V | V | ||
| Entropy | V | V | V | V | V | V | |
| value_A | V | V | V | V | V | V | V |
| value_C | V | V | V | V | V | V | |
| value_E | V | V | V | V | V | V | V |
| value_F | V | V | V | V | V | V | |
| duration_AC | V | V | V | V | V | V | |
| duration_BD | V | V | V | V | V | V | V |
| duration_CE | V | V | V | V | V | V | V |
| duration_EF | V | V | V | V | V | V | |
| slope_AL | V | V | V | V | V | V | V |
| slope_AR | V | V | V | V | V | V | V |
| slope_CL | V | V | V | V | V | V | V |
| slope_CR | V | V | V | V | |||
| slope_EL | V | V | V | V | V | ||
| slope_ER | V | V | V | V | V | V | V |
| slope_FL | V | V | V | V | V | V | V |
| slope_FR | V | V | V | V | |||
| slope_AC | V | V | V | V | V | V | |
| slope_CE | V | V | V | V | V | V | |
| slope_DE | V | V | V | V | V | ||
| slope_EF | V | V | V | V | V | V | |
| Integration | V | V | V | V | V | V | V |
| average_A | V | V | V | V | V | V | V |
| average_C | V | V | V | V | V | V | V |
| average_E | V | V | V | V | V | V | V |
Comparison of MAPE for original data and up-sampling data_
| (a) MAPE of different models utilizing the original data (1,000 Hz native). | ||||||
|---|---|---|---|---|---|---|
| Variable | Model | LR [11] | LSVR [11] | DTR [11] | XGBR | LGBMR |
| Peak force | 7.97 | 10.84 | 7.54 | 5.50 | 5.00 | |
| Second peak force | 24.88 | 28.31 | 23.84 | 19.16 | 18.07 | |
| Flight time | 2.59 | 4.63 | 2.85 | 2.09 | 2.04 | |
| Average loading rate | 34.32 | 33.54 | 30.68 | 23.50 | 23.59 | |
| Net impulse | 2.99 | 4.63 | 3.28 | 2.61 | 2.42 | |
| Peak power | 5.73 | 6.86 | 7.21 | 5.60 | 5.43 | |
| RFD | 21.12 | 23.16 | 21.73 | 17.50 | 16.56 | |
31 features extracted from the acceleration data
| Feature | Description |
|---|---|
| Mean | The mean of the acceleration data |
| SD | The standard deviation of the acceleration data |
| IQR | The interquartile range of the acceleration data |
| Skewness | The skewness of the acceleration data |
| Kurtosis | The kurtosis of the acceleration data |
| Frequency | The dominant frequency of the acceleration data |
| Entropy | The sample entropy of the acceleration data |
| value_A | The value of point A |
| value_C | The value of point C |
| value_E | The value of point E |
| value_F | The value of point F |
| duration_AC | The time interval from point A to point C |
| duration_BD | The time interval from point B to point D |
| duration_CE | The time interval from point C to point E |
| duration_EF | The time interval from point E to point F |
| slope_AL | The slope from (point A − 20 ms) to point A |
| slope_AR | The slope from point A to (point A + 20 ms) |
| slope_CL | The slope from (point C − 20 ms) to point C |
| slope_CR | The slope from point C to (point C + 20 ms) |
| slope_EL | The slope from (point E − 10 ms) to point E. |
| slope_ER | The slope from point E to (point E + 10 ms). |
| slope_FL | The slope from (point F − 10 ms) to point F |
| slope_FR | The slope from point F to (point F + 10 ms) |
| slope_AC | The slope from point A to point C |
| slope_CE | The slope from point C to point E |
| slope_DE | The slope from point D to point E |
| slope_EF | The slope from point E to point F. |
| Integration | The integration value before point C |
| average_A | The average value between (point A − 80 ms) and (point A + 20 ms) |
| average_C | The average value between (point C − 20 ms) and (point C + 180 ms). |
| average_E | The average value between (point E − 20 ms) and (point E + 180 ms) |