中文摘要：

基于群体稀疏分布的二维规则网格,提出了一个考虑群体自身的反馈机制、群体密度和群体流动的SIS模型。研究表明：反馈机制对系统的稳态感染比例有较大影响,但对传播阈值没有影响;在传播效率固定的前提下,群体密度越大,系统的稳态感染比例也越大,而且群体密度存在一个阈值,只有当群体密度大于该阈值时,疾病才能在群体中持续稳定地传播。另外,在群体密度不太大时,群体流动时的稳态感染比例要高于群体静止时的稳态感染比例,这说明群体流动更有利于疾病的传播。

英文摘要：

An SIS model related to feedback mechanism, crowd-density and crowd moving on sparse distributed regular lattices is proposed. It is shown that feedback greatly impacts on the stable infected ratio but does not impact on the spreading threshold of the system. If the spreading efficiency is fixed, the crowd-density is larger and the stable infected ratio is higher. Moreover, there is a crowd-density threshold in this model. Only when the crowd-density is above the threshold, the disease continuously and steadily spread in a crowd. The stable infected ratio of a moving crowd is higher than that of a static crowd in the case of low crowd-density, which indicates that the moving activity of individuals can promote the disease spread in the case of low crowd density.