Figure 1
![Figure 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs10033-021-00564-5/MediaObjects/10033_2021_564_Fig1_HTML.png)
Influences of \(\sigma\) and \(\lambda\) on \(f\) when the system is excited by an impulse signal: a \(\sigma^{2} = 1\), b \(\sigma^{2} = 10\), and c \(\sigma^{2} = 100\)
Influences of \(\sigma\) and \(\lambda\) on \(f\) when the system is excited by an impulse signal: a \(\sigma^{2} = 1\), b \(\sigma^{2} = 10\), and c \(\sigma^{2} = 100\)