Analysis of a Heroin Epidemic Model with Saturated Treatment Function

Figure 4

Illustration of the effect of increasing parameter that accounts for the saturation of heroin users. Here the parameters remain as in caption of Figure 3 except while is shown in the figure. The heroin eradication thresholds (i.e., ) corresponding to (a)–(d) are now 0.5204, 0.6038, 0.7314, and 0.9131, respectively.

(a)

(b)

(c)

(d)