Figure 12

Illustration of initial domains of the existence of an order-2 limit cycle for case (i), i.e. \(\pmb{y_{1}^{+}>y_{0}^{+}\geq Y_{\max}^{h}>b/p}\) . Four lines for \(y=Y_{\min}^{h}\) and \(y=Y_{\max}^{h}\) related to different \(V_{L}\) are plotted. The parameter values are as follows: \(b=1.8\), \(p=1.3\), \(c =0.52\), \(\omega =0.1\), \(q =0.23\), \(\delta =0.3\), \(\theta =0.8\), \(\tau=1.6\), and \(V_{L}=6.872, 6, 5, 4\).