On December 7,2022,the Chinese government optimized the current epidemic prevention and control policy,and no longer adopted the zero-COVID policy and mandatory quarantine measures.Based on the above policy changes,th...On December 7,2022,the Chinese government optimized the current epidemic prevention and control policy,and no longer adopted the zero-COVID policy and mandatory quarantine measures.Based on the above policy changes,this paper establishes a compartment dynamics model considering age distribution,home isolation and vaccinations.Parameter estimation was performed using improved least squares and Nelder-Mead simplex algorithms combined with modified case data.Then,using the estimated parameter values to predict a second wave of the outbreak,the peak of severe cases will reach on 8 May 2023,the number of severe cases will reach 206,000.Next,it is proposed that with the extension of the effective time of antibodies obtained after infection,the peak of severe cases in the second wave of the epidemic will be delayed,and the final scale of the disease will be reduced.When the effectiveness of antibodies is 6 months,the severe cases of the second wave will peak on July 5,2023,the number of severe cases is 194,000.Finally,the importance of vaccination rates is demonstrated,when the vaccination rate of susceptible people under 60 years old reaches 98%,and the vaccination rate of susceptible people over 60 years old reaches 96%,the peak of severe cases in the second wave of the epidemic will be reached on 13 July 2023,when the number of severe cases is 166,000.展开更多
基于In ternet的计算机辅助工业设计系统,基于案例的计算机辅助工业设计系统研究基础上,结合Case-based Reason ing CBR技术,采用语义隶属度分析的方法,提出了基于设计问题的程序型知识获取模型以及基于相似度计算的程序型知识检索算法...基于In ternet的计算机辅助工业设计系统,基于案例的计算机辅助工业设计系统研究基础上,结合Case-based Reason ing CBR技术,采用语义隶属度分析的方法,提出了基于设计问题的程序型知识获取模型以及基于相似度计算的程序型知识检索算法,为计算机辅助工业设计提供了一个新的思维方式,并在CB ID系统构建中得到实践与验证。展开更多
基金supported by the National Natural Science Foundation of China(12022113 and 12271314)Henry Fok Foundation for Young Teachers(171002)Outstanding Young Talents Support Plan of Shanxi Province.
文摘On December 7,2022,the Chinese government optimized the current epidemic prevention and control policy,and no longer adopted the zero-COVID policy and mandatory quarantine measures.Based on the above policy changes,this paper establishes a compartment dynamics model considering age distribution,home isolation and vaccinations.Parameter estimation was performed using improved least squares and Nelder-Mead simplex algorithms combined with modified case data.Then,using the estimated parameter values to predict a second wave of the outbreak,the peak of severe cases will reach on 8 May 2023,the number of severe cases will reach 206,000.Next,it is proposed that with the extension of the effective time of antibodies obtained after infection,the peak of severe cases in the second wave of the epidemic will be delayed,and the final scale of the disease will be reduced.When the effectiveness of antibodies is 6 months,the severe cases of the second wave will peak on July 5,2023,the number of severe cases is 194,000.Finally,the importance of vaccination rates is demonstrated,when the vaccination rate of susceptible people under 60 years old reaches 98%,and the vaccination rate of susceptible people over 60 years old reaches 96%,the peak of severe cases in the second wave of the epidemic will be reached on 13 July 2023,when the number of severe cases is 166,000.
