Now showing items 1-3 of 3
On constant-sign periodic solutions in modelling the spread of interdependent epidemics
(Cambridge University Press (CUP), 2006-01-01)
We consider the following model that describes the spread of n types of epidemics which are interdependent on each other: u(i)(t) = integral(t)(t-r) g(i)(t, s) f(i) (s, u(1)(s), u(2)(s),..., u(n)(s))ds, t is an element of ...
Multiplicity of positive periodic solutions to second order differential equations
(Cambridge University Press (CUP), 2006-04-01)
In this paper, we study the existence of positive periodic solutions to the equation x" = f (t, x). It is proved that such a equation has more than one positive periodic solution when the nonlinearity changes sign. ...
Existence and quasilinearization methods in hilbert spaces
(Elsevier BV, 2006-12-01)