Existence of Positive Periodic Solutions for Two Species Population Growth Model

Existence and nonexistence criteria are established for the positive periodic solutions of two species pop-ulation growth with periodic delay by applying continuation theorem of coincidence degree theory.     

一类具有偏差变元的非线性中立型微分方程周期解的存在性

利用k-集压缩算子拓扑度抽象连续定理和某些分析技巧,讨论了一类非线性中立型时滞微分方程x′(t)=f(x,x(t),x(t-τ1(t)),x′(t-τ2(t)))+p(t)的周期解问题,得到了其周期解存在的充分条件.     

非线性系统的主动容错控制

对一般的非线性系统提出了一种新的主动容错控制方法.系统正常工作时,采用基于迭代学习观测器的输出反馈控制策略,控制器为迭代学习观测器的状态和调节参数的函数,此输出反馈控制器能良好地镇定该非线性系统.当系统发生故障后,进行控制器重组,在调节参数的自适应调节律中引入了故障估计的信息,使得系统发生故障后包含故障估计信息的重组控制器仍然能使系统稳定,实现了非线性系统的主动容错控制.计算机模拟显示所提出算法的有效性.     

Existence of Two Solutions of Nonlinear m—Point Boundary Value Problems

Sufficient conditions for the existence of at least two positive solutions of a nonlinear m-points boundary value problems are established,The results are obtained by using a new fixed point theorem in cones.An example is provided to illustrate the theory.