Fig. 1.

Schematics representing the definitions of the OCDSs. The curves in each figure represent the autocorrelations in which the fast (a) and slow (b) dynamics are dominant. ${\mathrm{OCDS}}_e$ and ${\mathrm{OCDS}}_l$ are defined at the red and blue regions, respectively. In the present case, these regions are [12.8, 64] ms for ${\mathrm{OCDS}}_e$ and [64, 627.2] ms for ${\mathrm{OCDS}}_l$. The red and blue lines represent the slope for the ${\mathrm{OCDS}}_e$ and the ${\mathrm{OCDS}}_l$, respectively.