| In this paper, we discuss the following applied problems about two aspects by usingthe continuation theorem based on coincidence degree theory.Firstly, the existence of positive periodic solution for a periodic predator-prey systemwith sparse effect and Holling â…¢ type functional response is studied in chapter 2. A setof sufficient conditions is derived about it, which improve some known results.Secondly, by using the coincidence degree theory based on the chapter 2, theexistence of positive periodic solution for a periodic predator-prey system with sparseeffect and Beddington-DeAngelis functional response is studied in chapter 3. If s (t ) = 0in this model, which is a general form of the classical predator-prey system withBeddington-DeAngelis functional response. A sufficient condition is also derived about it,which improve some known results. |
