报告题目：Basic Reproduction Ratios for Periodic Compartmental Models with Time Delay
报告摘要：In this talk, I will report our recent research on basic reproduction ratio R0 for time-delayed compartmental population models in a periodic environment. It is proved that R0 serves as a threshold value for the stability of the zero solution of the associated periodic linear systems. An extension of such a theory to spatial population models and a general algorithm for the numerical computation of R0 will be discussed. As an illustrative example, we also apply the developed theory to a periodic SEIR model with an incubation period and obtain a threshold result on its global dynamics in terms of R0.