Fig. 9.

We show log–log plots of $F\left(n\right)$ for (a) white noise, (b) Brown noise, (c) the HRV of a young female, and (d) the HRV of an aged female. In (a) and (b), the exponent $\alpha$ was calculated on the right side of the line, $n=100$. In (c) and (d), the exponent of the intermediate time scale ${\alpha }_i$ was calculated between the two lines (the intermediate range), $n=100$ and $n=500$, whereas the exponent of the long time scale ${\alpha }_l$ was calculated on the right side of the line $n=500$ (the long range). The fitted regression is shown by the solid line, and the upper and lower thinner lines represent 95% confidence intervals.