摘要
Since 1974, studying the original delay differential equation given by Kaplan and Yorke is about the problem on the existence of its periodic solutions, there have been a series of interesting and significant results in the previous literature. In this paper, we present a survey of some basic results. Some interesting open problems are also
Since 1974, studying the original delay differential equation given by Kaplan and Yorke is about the problem on the existence of its periodic solutions, there have been a series of interesting and significant results in the previous literature. In this paper, we present a survey of some basic results. Some interesting open problems are also
基金
partially supported by National Natural Science Foundation of China
Program for Changjiang Scholars and Innovative Research Team in University(IRT1226)