This paper discusses the application of a pulse vaccination strategy to prevent and control some infectious diseases, which is described by age-structured SIR model in which susceptible and recovered individuals are s...This paper discusses the application of a pulse vaccination strategy to prevent and control some infectious diseases, which is described by age-structured SIR model in which susceptible and recovered individuals are structured by chronological age, while infected individuals are structured by infection age （duration since infection）. The time dependent disease-free equilibrium is determined, for which an explicit expression exists. The analytical results show that there exists a globally stable infectiomfree situation if the impulsive period T and proportion p satisfy Ro（p,T） 〈 1. Optimal problem is discussed： Pulse vaccination strategy with minimal costs at given R0（p, T） 〈 1.展开更多
文摘无线输能技术因其不受线缆约束,能够适应各种地形和应用场合而受到重视。整流天线作为无线输能技术的重要组成部分,其整流效率直接影响整个无线输能系统的优劣。为提高整流效率,结合SIR结构设计了一个具有谐波抑制功能的5.8 GHz接收天线,从而整合接收天线和低通滤波器的部分性能,以消除传统整流天线中天线和滤波器之间的损耗和滤波器自身的损耗,从而提高整体整流效率。结果显示,该天线带宽仅为120 MHz,在二次谐波处回波损耗仅为-2.5 d B,性能良好。
基金supported by Natural Science Foundation of Henan Province under Grant No.092300410206Science and Technology Program of Educational Department of Henan Province under Grant No. 2009A110015
文摘This paper discusses the application of a pulse vaccination strategy to prevent and control some infectious diseases, which is described by age-structured SIR model in which susceptible and recovered individuals are structured by chronological age, while infected individuals are structured by infection age （duration since infection）. The time dependent disease-free equilibrium is determined, for which an explicit expression exists. The analytical results show that there exists a globally stable infectiomfree situation if the impulsive period T and proportion p satisfy Ro（p,T） 〈 1. Optimal problem is discussed： Pulse vaccination strategy with minimal costs at given R0（p, T） 〈 1.
