Algorithm 1 EMD decomposition steps.

1:Identify all extrema (maxima and minima) 2:Create the upper $u\left(t\right)$ and lower $l\left(t\right)$ envelopes by connecting the maxima and minima separately with a cubic spline curve 3:Find the mean of the envelopes as $m\left(t\right)=\frac{u\left(t\right)+l\left(t\right)}{2}$ 4:Take the difference between the data and the mean: $d\left(t\right)=x\left(t\right)-m\left(t\right)$ 5:Decide whether $d\left(t\right)$ is an IMF or not by checking the two basic conditions described above and the stoppage criterion 6:If $d\left(t\right)$ is not an IMF, repeat steps 1–5 on $d\left(t\right)$ as many times as needed until it satisfies the conditions 7:If $d\left(t\right)$ is an IMF, assign it to an IMF component $c\left(t\right)$ 8:Repeat steps 1–7 on the residue, $r\left(t\right)=x\left(t\right)-c\left(t\right)$, as input data 9:The process stops when the residue contains no more than one extremum