标题： 从SEIR模型估计的COVID-19基本再生数：与2020年人口流动的相关性 显示英文标题

标题： COVID-19 reproduction number estimated from SEIR model: association with people's mobility in 2020

摘要： 本文是对全球范围内两个流行病学问题的探索性研究。 疾病传播有多快？ 针对人们的限制措施（尤其是流动限制）是否达到了预期效果？ 为回答第一个问题，我们提出了一种基于SEIR模型的流行病再生数估计工具（二次感染数$R_t$），并将其与非模型$R_t$估计进行比较。 为了衡量不同国家的$R_t$，从约翰霍普金斯大学系统科学与工程中心（CSSE）获取了冠状病毒每日感染、康复、死亡的实时数据。 为了评估2020年新冠疫情中流动限制的有效性，展示了$R_t$与人们流动（基于苹果流动指数）之间的相关性。 这些相关性考虑了12个国家，其中大多数国家的相关性为负。 这表明流动限制的实施存在延迟——这些国家是在新新冠病例增长后才实施限制，而不是预防性地实施。 显示英文摘要

摘要： This paper is an exploratory study of two epidemiological questions on a worldwide basis. How fast is the disease spreading? Are the restrictions (especially mobility restrictions) for people bring the expected effect? To answer the first question, we propose a tool for estimating the reproduction number of epidemic (the number of secondary infections $R_t$) based on the SEIR model and compare it with an non-model $R_t$ estimation. To measure the $R_t$ of COVID-19 for different countries, real-time data on coronavirus daily cases of infections, recoveries, deaths are retrieved from the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. To assess the effectiveness of mobility restrictions for the COVID-19 pandemic in 2020, the correlations between the $R_t$ and people's mobility (based on the Apple mobility index) are presented. The correlations were considered for 12 countries and for most of them, the correlations are negative. This shows a delay in the implementation of mobility restrictions - the countries imposed them in response to growth of new COVID-19 cases, rather than preventively.