A robust SEIR epidemic disease model with a profitless delay and verti- cal transmission is formulated,and the dynamics behaviors of the model under pulse vaccination are analyzed.By use of the discrete dynamical system determined by the stroboscopic map,an‘infection-free’periodic solution is obtained,further,it is shown that the‘infection-free’periodic solution is globally attractive when some parameters of the model are under appropriate conditions.Using the theory on delay functional and impulsive differential equatibn,the sufficient condition with time delay for the perma- nence of the system is obtained,and it is proved that time delays,pulse vaccination and vertical transmission can bring obvious effects on the dynamics behaviors of the model. The results indicate that the delay is‘profitless’.
We consider a delayed stage-structured pest management predator-prey system with impulsive transmitting on predator and chemical control on prey.Sufficient conditions of the global attractiveness of the pest-extinction boundary periodic solution and permanence of the system are obtained.We also prove that all solutions of the system are uniformly ultimately bounded.Our results provide reliable tactical basis for practical pest management.
A pest management SI model with impulsive releases of infective pests and spraying pesticides is proposed and investigated. We prove that all solutions of the model are uniformly ultimately bounded. We also obtain the sufficient conditions of globally asymptotic stability periodic solution of pest-extinction and permanence of the model. The approach of combining impulsive releasing infective pests with impulsive spraying pesticides provides reliable tactical basis for the practical pest management.
