Related Experiment Video
Updated: May 19, 2026

Predicting the Effectiveness of Population Replacement Strategy Using Mathematical Modeling
Published on: July 4, 2007
A note on persistence about structured population models
1Graduate School of Mathematical Sciences, The University of Tokyo, Tokyo, Japan. kkawachi@ms.u-tokyo.ac.jp
Abstract:
In this paper, we report some results on persistence in two structured population models: a chronic- age-structured epidemic model and an age-duration-structured epidemic model. Regarding these models, we observe that the system is uniformly strongly persistent, which means, roughly speaking, that the proportion of infected subpopulation is bounded away from 0 and the bound does not depend on the initial data after a sufficient long time, if the basic reproduction ratio is larger than one. We derive this by adopting Thieme's technique, which requires some conditions about positivity and compactness. Although the compactness condition is rather difficult to show in general infinite-dimensional function spaces, we can apply Fréchet-Kolmogorov L(1)-compactness criteria to our models. The two examples that we study illuminate a useful method to show persistence in structured population models.
Related Concept Videos
Mechanistic Models: Compartment Models in Individual and Population Analysis
Modeling with Differential Equations
Population Growth
Conservation of Small Populations
Conservation of Declining Populations
Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...

