Multiple Periodic Solutions For Two Kinds Of Differential Equations With A General Piecewise Constant Argument

In this thesis,we discuss the existence of multiple periodic solutions for the delay differential equation with a general piecewise constant argument and the Neural network models.In chapter 1,we introduce the backgrounds of the problem and the main results of this thesis.In chapter 2,we introduce the basic definitions and lemma.In chapter 3,we prove the existence of multiple periodic solutions for the delay differential equation with a general piecewise constant argument:,and applying the results to Nicholson's blowflies type model:,we obtain that the existence theorems of at least two positive periodic solutions for this models.In chapter 4,we obtain that the existence theorems of periodic solution and multiple nonnegative periodic solutions for the Neural network models:(?).