Table 10.
Summary of the correlation coefficients.
| No. | Feature domain | Max. absolute CC |
Physical meaning |
|---|---|---|---|
| 1 | Time interval | 0.286 | sd_IntSys |
| 2 | State amplitude | -0.159 | sd_Amp_S2Sys |
| 3 | Energy | 0.345 | Standard deviation of Ratio_state_energydia_cycle |
| 4 | High-order statistics | 0.185 | sd_S1_kurtosis |
| 5 | Cepstrum | 0.216 | The seventh cepstrum coefficient of S2 state |
| 6 | Frequency spectrum of state | 0.417 | Spectrum value of 30 Hz of S2 state |
| 7 | cyclostationarity | -0.240 | Sharpness of the peak of cycle frequency spectral density |
| 8 | Entropy | -0.374 | Average value of sample entropy of diastolic state |
| 9 | Frequency spectrum of records | -0.272 | Ratio of spectrum magnitude sum in [90 120] Hz |