Ramida Lamoonwong.. Dynamical analysis of SIRS epidemic models with general infectious force functions. Doctoral Degree(Applied Mathematics). King Mongkut's University of Technology North Bangkok. Central Library. : King Mongkut's University of Technology North Bangkok, 2022.
Dynamical analysis of SIRS epidemic models with general infectious force functions
Abstract:
In epidemiological models, the infectious force function plays an important
role in the transmission of diseases. The infectious force function may be affected
by many factors when a disease enters a population, such as change of behavior of
people, density of population, life style and media coverage. In this study, we use
a general infectious force function and not specialize it to a particular form. We
also develop and study three classes of susceptible-infectious-recovered-susceptible
epidemic models with general infectious force function, namely, deterministic and
stochastic autonomous models and a deterministic non-autonomous model. Formulas for the disease-free and endemic equilibria are derived. The next-generation
method is used to calculate the basic reproduction number and to obtain conditions
for the local asymptotic stability of the disease-free equilibrium and the existence
of the endemic equilibrium. In addition, Lyapunov functions are used to prove
global stability of the equilibria for the deterministic model. In addition, we
analyze dynamical properties of the solutions for the stochastic model and study
the asymptotic behavior around the equilibria. Finally, for the non-autonomous
system, we find necessary and sufficient conditions for extinction, persistence, and
permanence of the diseases. For all problems, we will apply mathematical software
to obtain numerical results.