31 citations
5 papers
Optimal control of non-autonomous SEIRS models with vaccination and treatment
Joaquim P. Mateus, Paulo Rebelo, Silvério Rosa +2
We study an optimal control problem for a non-autonomous SEIRS model with incidence given by a general function of the infective, the susceptible and the total population, and with…
Matrix approach to hypercomplex Appell polynomials
Lidia Aceto, Helmuth Robert Malonek, Graça Tomaz
Recently the authors presented a matrix representation approach to real Appell polynomials essentially determined by a nilpotent matrix with natural number entries. It allows to co…
Existence of periodic solutions of a periodic SEIRS model with general incidence
César M. Silva, Joaquim P. Mateus
For a family of periodic SEIRS models with general incidence, we prove the existence of at least one endemic periodic orbit when R_0>1. Additionally, we prove the existence of a un…
A unified matrix approach to the representation of Appell polynomials
Lidia Aceto, Helmuth R. Malonek, Graça Tomaz
In this paper we propose a unified approach to matrix representations of different types of Appell polynomials. This approach is based on the creation matrix - a special matrix whi…
A non-autonomous SEIRS model with general incidence rate
Joaquim P. Mateus, César M. Silva
For a non-autonomous SEIRS model with general incidence, that admits [T. Kuniya and Y. Nakata, Permanence and extinction for a nonautonomous SEIRS epidemic model, Appl. Math. Compu…