Modeling a Tumor Growth with Piecewise Constant Arguments

Modeling a Tumor Growth with Piecewise Constant Arguments

β 0 x(⟦t⟧) − β 1 x(⟦t − 1⟧)) + γ 1 x(⟦t⟧) + γ 2 x(⟦t − 1⟧)}, where the parameters α, β 0 , β 1 , and r denote positive numbers, γ 1 and γ 2 are negative numbers and ⟦t⟧ is the integer part of t ∈ [0,∞). Equation (A) explains a brain tumor growth, where γ 1 is embedded to show the drug effect on the tumor and γ 2 is a rate that causes a negative effect by the immune system on the tumor populatio...

On numerical approximation using differential equations with piecewise-constant arguments

In this paper we give a brief overview of the application of delay differential equations with piecewise constant arguments (EPCAs) for obtaining numerical approximation of delay differential equations, and we show that this method can be used for numerical approximation in a class of age-dependent population models. We also formulate an open problem for a qualitative behaviour of a class of li...

Oscillation of nonlinear impulsive differential equations with piecewise constant arguments

denotes the greatest integer function, and x−1, x0 are given real numbers. Since 1980’s differential equations with piecewise constant arguments have attracted great deal of attention of researchers in mathematical and some of the others fields in science. Piecewise constant systems exist in a widely expanded areas such as biomedicine, chemistry, mechanical engineering, physics, etc. These kind...

Ergodic Type Solutions of Differential Equations with Piecewise Constant Arguments

We summarize the conditions discovered for the existence of new ergodic type solutions (asymptotically almost periodic, pseudo almost periodic, . . .) of differential equations with piecewise constant arguments. Their existence is characterized by introducing a new tool, the ergodic sequences. 2000 Mathematics Subject Classification. 39-02, 34K14, 34D09.

Oscillation of a Class of Impulsive Differential Equations with Continuous and Piecewise Constant Arguments