. 2018 Dec 11;18(12):4381. doi: 10.3390/s18124381

Table 1.

Signal characterization parameters.

Features	Signal Components
Features	F_p	F_f	F_c	a_p	a_f	a_c	AE
Mean	$X_{F_{p}}^{j}$	$X_{F_{f}}^{j}$	$X_{F_{c}}^{j}$	$X_{a_{p}}^{j}$	$X_{a_{f}}^{j}$	$X_{a_{c}}^{j}$	$X_{A E}^{j}$
Standard deviation	$σ_{F_{p}}^{j}$	$σ_{F_{f}}^{j}$	$σ_{F_{c}}^{j}$	$σ_{a_{p}}^{j}$	$σ_{a_{f}}^{j}$	$σ_{a_{c}}^{j}$	$σ_{A E}^{j}$
Peak to peak amplitude	$P P_{F_{p}}^{j}$	$P P_{F_{f}}^{j}$	$P P_{F_{c}}^{j}$	$P P_{a_{p}}^{j}$	$P P_{a_{f}}^{j}$	$P P_{a_{c}}^{j}$	$P P_{A E}^{j}$
Skewness	$S_{F_{p}}^{j}$	$S_{F_{f}}^{j}$	$S_{F_{c}}^{j}$	$S_{a_{p}}^{j}$	$S_{a_{f}}^{j}$	$S_{a_{c}}^{j}$	$S_{A E}^{j}$
Kurtosis	$K_{F_{p}}^{j}$	$K_{F_{f}}^{j}$	$K_{F_{c}}^{j}$	$K_{a_{p}}^{j}$	$K_{a_{f}}^{j}$	$K_{a_{c}}^{j}$	$K_{A E}^{j}$
Energy	$E_{F_{p}}^{j}$	$E_{F_{f}}^{j}$	$E_{F_{c}}^{j}$	$E_{a_{p}}^{j}$	$E_{a_{f}}^{j}$	$E_{a_{c}}^{j}$	$E_{A E}^{j}$
Shannon entropy	$S E_{F_{p}}^{j}$	$S E_{F_{f}}^{j}$	$S E_{F_{c}}^{j}$	$S E_{a_{p}}^{j}$	$S E_{a_{f}}^{j}$	$S E_{a_{c}}^{j}$	$S E_{A E}^{j}$

Where, $j = t$ is time for TDA method, SSA $j = λ_{1}, \dots, λ_{L}$ are number of the eigenvalues for SSA method, PSD $j = f 1, \dots, f 4$ are frequency ranges for PSD, and $j = A, \dots, A D A D A$ are frequency ranges (packets) for the WPT.