In this paper, we consider the boundary value problems of a one-dimensional steady-state SIS epidemic reaction-diffusion-advection system in the following two cases: (ⅰ) the advection rate is relatively large comparing to the diffusion rates of infected and susceptible populations; (ⅱ) the diffusion rate of the susceptible population approaches zero. By introducing a singular parameter, the system can be viewed as a singularly perturbed problem. By the renormalization group method, we construct the first-order approximate solutions and obtain error estimates.

中文翻译：

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SIS问题的奇异重整化组方法

在以下两种情况下，我们考虑一维稳态SIS流行病反应扩散-对流系统的边​​值问题：（ⅰ）与感染和易感者的扩散率相比，对流率相对较大人口; （ⅱ）易感人群的扩散率接近零。通过引入奇异参数，可以将系统视为一个奇摄动问题。通过重归一化组方法，我们构造了一阶近似解并获得误差估计。