In this section, we assume that the coefficients of model (1.1) are periodic with common period, that is, (3.1).
Recently, assuming that the biological and environmental parameters are periodic with a common period, Chen [26] considered the same equation but with periodic parameters.
where,, are periodic with a common period,,, being -periodic.
The coefficients of model (3.2) are all periodic with the common period 20.
We will further investigate the existence and stability of the periodic solution for model (1.1) under the assumption that the coefficients of model (1.1) are all periodic with a common period.
We assume that (A t)) and (f t,u)) are periodic in t with a common period (xi>0).
The output regulation problem is addressed and solved in the presence of unknown periodic reference and/or disturbance signals of known common period.
In this section, we assume that all the coefficients of system (1.3) are positive sequences with common periodic ω, where ω is a fixed positive integer, stands for the prescribed common period of the parameters in system (1.3), then the system (1.3) is an ω-periodic system for this case.
Note that the main result of [17] cannot be used for general periodic functions r, s (which do not have any common period).
We investigate perturbed second order Euler type half-linear differential equations with periodic coefficients and with the perturbations given by the finite sums of periodic functions which do not need to have any common period.
Depression may appear at any age, but its most common period of onset is in young adulthood.
