In this paper,a kind of discrete delay food-limited model obtained by the Euler method is investigated,where the discrete delay τ is regarded as a parameter.By analyzing the associated characteristic equation,the lin...In this paper,a kind of discrete delay food-limited model obtained by the Euler method is investigated,where the discrete delay τ is regarded as a parameter.By analyzing the associated characteristic equation,the linear stability of this model is studied.It is shown that Neimark-Sacker bifurcation occurs when τ crosses certain critical values.The explicit formulae which determine the stability,direction,and other properties of bifurcating periodic solution are derived by means of the theory of center manifold and normal form.Finally,numerical simulations are performed to verify the analytical results.展开更多
The normal forms of generalized Neimark-Sacker bifurcation are extensively studied using normal form theory of dynamic system. It is well known that if the normal forms of the generalized Neimark-Sacker bifurcation ar...The normal forms of generalized Neimark-Sacker bifurcation are extensively studied using normal form theory of dynamic system. It is well known that if the normal forms of the generalized Neimark-Sacker bifurcation are expressed in polar coordinates, then all odd order terms must, in general, remain in the normal forms. In this paper, five theorems are presented to show that the conventional Neimark-Sacker bifurcation can be further simplified. The simplest normal forms of generalized Neimark-Sacker bifurcation are calculated. Based on the conventional normal form, using appropriate nonlinear transformations, it is found that the generalized Neimark-Sacker bifurcation has at most two nonlinear terms remaining in the amplitude equations of the simplest normal forms up to any order. There are two kinds of simplest normal forms. Their algebraic expression formulas of the simplest normal forms in terms of the coefficients of the generalized Neimark-Sacker bifurcation systems are given.展开更多
本文研究了捕食者具有Michaelis-Menten型离散捕食者–猎物模型的动力学问题。为了探索模型的丰富动力学性质,采用欧拉近似得到离散时间的Leslie-Gower模型。给出了内部不动点的存在性及其局部渐近稳定性。在此基础上,利用分岔理论和中...本文研究了捕食者具有Michaelis-Menten型离散捕食者–猎物模型的动力学问题。为了探索模型的丰富动力学性质,采用欧拉近似得到离散时间的Leslie-Gower模型。给出了内部不动点的存在性及其局部渐近稳定性。在此基础上,利用分岔理论和中心流形定理,研究了倍周期分岔和Neimark-Sacker分岔。并取临界参数进行数值模拟,验证了倍周期分岔和Neimark-Sacker分岔的存在性。In this paper, we investigate the dynamics of predator with Michaelis-Menten discrete predator-prey model. In order to explore the rich dynamic properties of the model, the discrete-time Leslie-Gower model is obtained by using Euler approximation. The existence of internal fixed points and their local asymptotic stability are given. On this basis, using bifurcation theory and central manifold theorem, the period-doubling bifurcation and Neimark-Sacker bifurcation are studied. The existence of period-doubling bifurcation and Neimark-Sacker bifurcation is verified by numerical simulation with critical parameters.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61272069,61272114,61073026,61170031,and 61100076)
文摘In this paper,a kind of discrete delay food-limited model obtained by the Euler method is investigated,where the discrete delay τ is regarded as a parameter.By analyzing the associated characteristic equation,the linear stability of this model is studied.It is shown that Neimark-Sacker bifurcation occurs when τ crosses certain critical values.The explicit formulae which determine the stability,direction,and other properties of bifurcating periodic solution are derived by means of the theory of center manifold and normal form.Finally,numerical simulations are performed to verify the analytical results.
基金Supported by National Natural Science Foundation of China (No10872141)Doctoral Foundation of Ministry of Education of China (No20060056005)Natural Science Foundation of Tianjin University of Science and Technology (No20070210)
文摘The normal forms of generalized Neimark-Sacker bifurcation are extensively studied using normal form theory of dynamic system. It is well known that if the normal forms of the generalized Neimark-Sacker bifurcation are expressed in polar coordinates, then all odd order terms must, in general, remain in the normal forms. In this paper, five theorems are presented to show that the conventional Neimark-Sacker bifurcation can be further simplified. The simplest normal forms of generalized Neimark-Sacker bifurcation are calculated. Based on the conventional normal form, using appropriate nonlinear transformations, it is found that the generalized Neimark-Sacker bifurcation has at most two nonlinear terms remaining in the amplitude equations of the simplest normal forms up to any order. There are two kinds of simplest normal forms. Their algebraic expression formulas of the simplest normal forms in terms of the coefficients of the generalized Neimark-Sacker bifurcation systems are given.
文摘本文研究了捕食者具有Michaelis-Menten型离散捕食者–猎物模型的动力学问题。为了探索模型的丰富动力学性质,采用欧拉近似得到离散时间的Leslie-Gower模型。给出了内部不动点的存在性及其局部渐近稳定性。在此基础上,利用分岔理论和中心流形定理,研究了倍周期分岔和Neimark-Sacker分岔。并取临界参数进行数值模拟,验证了倍周期分岔和Neimark-Sacker分岔的存在性。In this paper, we investigate the dynamics of predator with Michaelis-Menten discrete predator-prey model. In order to explore the rich dynamic properties of the model, the discrete-time Leslie-Gower model is obtained by using Euler approximation. The existence of internal fixed points and their local asymptotic stability are given. On this basis, using bifurcation theory and central manifold theorem, the period-doubling bifurcation and Neimark-Sacker bifurcation are studied. The existence of period-doubling bifurcation and Neimark-Sacker bifurcation is verified by numerical simulation with critical parameters.
