IB DP 数学 IA 写作 Covid-19

更常见的是，我关注了每天的新增感染人数I(t)和康复人数R(t);而且在信息被推送时，我注意到了以上两种人数的曲线总是呈现种特定的模式。我期盼疫情能得以被控制住，直至结束。我想弄清楚究竟是什么样的传播机制。比如：感染人数I(t),易感染人数S(t), 康复人数R(t)的变化是否存在某种相关性？

是的，我Google了，就是用一组微分方程组描述的SIR大疫情模型。

英文：

More commonly, I have followed the daily numbers of new infections I(t) and recoveries R(t); and from the daily updates, I have noticed that the curves of these two numbers always show a particular pattern. I hope that the epidemic will be contained until it is over. I wanted to find out what the mechanism of transmission was. For example, is there a correlation between the number of infected I(t), the number of susceptible S(t) and the number of recovered R(t)?

Yes, I Googled it, it's the SIR pandemic model des-cribed by a set of differential equations.