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一类具有饱和治愈率和饱和接触率的流行病动力学模型研究
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作者 李豪 张艳 《赣南师范学院学报》 2011年第3期26-28,共3页
主要建立了一类带有饱和治愈率和饱和接触率的SIRS传染病模型,研究得到了该模型的无病平衡点及地方病平衡点的局部稳定性,同时,借助构造Liapunov函数,给出了无病平衡点和地方病平衡点全局渐近稳定的条件.
关键词 流行病动力学模型 饱和治愈率 饱和接触率 稳定性
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确定动力学流行病模型阈值的一种方法 被引量:1
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作者 钟玲 翁甲强 《物理学报》 SCIE EI CAS CSCD 北大核心 2000年第4期626-630,共5页
采用六方格子上的动力学流行病模型描述流体凝固过程 ,根据流体中所含杂质粒子与固态粒子间的短程推斥作用 ,导出了被陷杂质粒子与固态粒子的密度比方程 .并得到方程所含的两个变量 χ 与r之间有如下关系 :当r为有限值时 ,分形生长局限... 采用六方格子上的动力学流行病模型描述流体凝固过程 ,根据流体中所含杂质粒子与固态粒子间的短程推斥作用 ,导出了被陷杂质粒子与固态粒子的密度比方程 .并得到方程所含的两个变量 χ 与r之间有如下关系 :当r为有限值时 ,分形生长局限于该区域 ;r无解时 ,集团可无限生长 ,在平面上形成较密集集团 ,维数Db→ 2 ;仅当r的解为∞时 ,分形生长可无限进行 ,该点 χ 即为阈值 χc.由此 ,得到六方格子上阈值 χc≈ 0 65 5 ,与计算机模拟结果相符合 ,大于四方格子的结果 χc(s) (∞ ) =0 5 60± 0 0 0 5 . 展开更多
关键词 动力学流行病模型 阈值 流体凝固
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城市时空大数据驱动的新型冠状病毒传播风险评估——以粤港澳大湾区为例 被引量:17
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作者 夏吉喆 周颖 +4 位作者 李珍 李帆 乐阳 程涛 李清泉 《测绘学报》 EI CSCD 北大核心 2020年第6期671-680,共10页
2019年末至2020年初新型冠状病毒(COVID-19)的快速传播对中国与世界的公共卫生带来巨大的挑战。如何科学合理地评估新型冠状病毒传播风险并制定相应防疫管控措施,是各国所面临的难题,也是科学防治与精准施策的重要依据之一。作为我国最... 2019年末至2020年初新型冠状病毒(COVID-19)的快速传播对中国与世界的公共卫生带来巨大的挑战。如何科学合理地评估新型冠状病毒传播风险并制定相应防疫管控措施,是各国所面临的难题,也是科学防治与精准施策的重要依据之一。作为我国最重要的城市群之一,粤港澳大湾区受本次新型冠状病毒影响较大,且春节假期后大量的复工回流人口进一步带来潜在的传播风险。本文面向粤港澳大湾区新型冠状病毒传播风险评估的紧迫需求,结合大湾区多源城市时空大数据与流行病动力学模型,构建适宜大湾区的改进模型,并对新型冠状病毒在大湾区的传播风险和各类防疫管控措施效果进行评估与模拟。首先,引入动态复工回流人口和聚集热点改进现有动力学模型(SEIR模型),对现有动力学模型在不同空间评估单元的传播参数进行纠偏,加强模型在大湾区评估中的适宜性;利用手机信令等多源城市大数据,构建更精细化的人口、疾病流动矩阵和相应的传染病动力学模型,以满足各级防疫部门精细化(如村(社区)级)风险评估的迫切需求。模拟结果表明,相对经典SEIR模型,改进模型在大湾区的传播风险评估中具有更强的适宜性;大湾区高强度的人口流动为病毒的传播带来较高的风险;防疫部门所采取各类管控措施对病毒在大湾区的传播具有较强的抑制作用。 展开更多
关键词 新型冠状病毒 粤港澳大湾区 时空大数据 流行病动力学模型
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DYNAMICS OF SIS EPIDEMIC MODEL WITH THE STANDARD INCIDENCE RATE AND SATURATED TREATMENT FUNCTION 被引量:2
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作者 JINGJING WEI JING-AN CUI 《International Journal of Biomathematics》 2012年第3期43-60,共18页
An SIS epidemic model with the standard incidence rate and saturated treatment func- tion is proposed. The dynamics of the system are discussed, and the effect of the capacity for treatment and the recruitment of the ... An SIS epidemic model with the standard incidence rate and saturated treatment func- tion is proposed. The dynamics of the system are discussed, and the effect of the capacity for treatment and the recruitment of the population are also studied. We find that the effect of the maximum recovery per unit of time and the recruitment rate of the popula- tion over some level are two factors which lead to the backward bifurcation, and in some cases, the model may undergo the saddle-node bifurcation or Bogdanov-Takens bifurca- tion. It is shown that the disease-free equilibrium is globally asymptotically stable under some conditions, Numerical simulations are consistent with our obtained results in the- orems, which show that improving the efficiency and capacity of treatment is important for control of disease. 展开更多
关键词 SIS epidemic model saturated treatment function backward bifurcation stability.
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GLOBAL DYNAMICS OF A DIFFERENTIAL SUSCEPTIBILITY MODEL
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作者 M. R. RAZVAN S. YASAMAN 《International Journal of Biomathematics》 2012年第5期219-238,共20页
An SIS epidemiological model in a population of varying size with two dissimilar groups of susceptible individuals has been analyzed. We prove that all the solutions tend to the equilibria of the system. Then we use t... An SIS epidemiological model in a population of varying size with two dissimilar groups of susceptible individuals has been analyzed. We prove that all the solutions tend to the equilibria of the system. Then we use the Poincar~ Index theorem to determine the number of the rest points and their stability properties. It has been shown that bistability occurs for suitable values of the involved parameters. We use the perturbations of the pitchfork bifurcation points to give examples of all possible dynamics of the system. Some numerical examples of bistability and hysteresis behavior of the systeIn has been also provided. 展开更多
关键词 Epidemiological model differential susceptibility disease-free equilibrium endemic equilibrium Poincar~ index bifurcation.
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Dynamics of SVEIS epidemic model with distinct incidence
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作者 N. Nyamoradi M. Javidi B. Ahmad 《International Journal of Biomathematics》 2015年第6期99-117,共19页
In this paper, we study the global dynamics of a SVEIS epidemic model with distinct incidence for exposed and infectives. The model is analyzed for stability and bifurcation behavior. To account for the realistic phen... In this paper, we study the global dynamics of a SVEIS epidemic model with distinct incidence for exposed and infectives. The model is analyzed for stability and bifurcation behavior. To account for the realistic phenomenon of non-homogeneous mixing, the effect of diffusion on different population subclasses is considered. The diffusive model is analyzed using matrix stability theory and conditions for Turing bifurcation are derived. Numerical simulations support our analytical results on the dynamic behavior of tile model. 展开更多
关键词 SVEIS epidemic model DIFFUSION Turing bifurcation stability basic repro-duction number numerical simulation.
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