应用微分方程分支理论,研究了具有时滞和饱和接触率的SIRS模型,以时滞τ为分支参数,运用Hopf分支理论,得到当时滞τ充分小时正平衡点是局部渐近稳定的,当τ经过一系列临界值时模型出现Hopf分支。用Matlab软件进行数值仿真验证了结论的正确性。
This thesis researches SIRS models with delayed and saturation incidence by using the bifurcation method of differential equations. By means of the Hopf bifurcation theorem and considering the delay τ as a bifurcation parameter,the endemic equilibrium is locally stable when τ is small enough and Hopf bifurcation occurs when τ passes through some critical values. Matlab is employed to carry out numerical simulation to verify the results.