一类参数不确定广义时滞系统的H∞保性能鲁棒控制

针对一类状态时滞的参数不确定性广义系统,讨论了它的保性能控制问题.目的是对状态时滞的参数不确定广义系统,提出它的时滞无关保性能鲁棒控制器的一个设计方法.首先给出了广义时滞系统正则、脉冲自由且稳定的严格线性矩阵不等式表示的时滞无关充分条件;然后采用线性矩阵不等式方法,给出参数不确定性广义时滞系统的时滞无关保性能控制问题可解的一个严格线性矩阵不等式表示的充分条件,在此条件可解时,给出了时滞无关保性能鲁棒控制器表达式,以及相应的可保性能指标.最后给出了所提出方法的应用.

Abstract：

The guaranteed cost control problem is studied for singular systems with time-delay and parameter uncertainty in order to design a delay-independent guaranteed cost controller for singular systems with time-delay and parameter uncertainty. First, a delay-independent sufficient condition is derived, which is expressed by strict linear matrix in-equality (LMI) for singular systems with time-delay to be regular, impulse free and stable. Then, the delay-independent sufficient condition for the existence of guaranteed cost controller is given in terms of strict linear matrix inequalities via LMI approach. When these LMI are feasible, an explicit expression of delay-independent robust guaranteed cost controllers and the corresponding guaranteed cost of the systems are obtained. Finally, a numerical example is provided to demonstrate the application of the proposed method.     

一类具有非线性发生率的SIS传染病模型的定性分析

应用微分方程定性理论,研究了一类具有非线性发生率的SIS传染病模型.给出了该系统极限环的存在性、唯一性以及无病平衡点和地方病平衡点的全局渐近稳定性的充分条件.

Abstract：

An epidemiological model with nonlinear incidence is studied. By using the qualitative theory of ordinary differential equations, sufficient conditions are obtained for the existence and uniqueness of the limit cycles and the global asymptotic stability of the disease-free equilibrium and the endemic equilibrium to the system.     

一类中立型微分方程周期解的存在性与唯一性

利用Krasnoselskii不动点理论,结合分析的方法,对一类中立型微分方程存在周期解进行定性与定量研究,获得了这类微分方程周期解存在性与唯一性的充分条件.

Abstract：

Using the analytical method and utilizing Krasnoselskii's fixed point theory, this paper qualitatively and quantitatively study the existence of the periodic solutions for a class of neutral differential equation, and obtains some sufficient conditions of existence and uniqueness of periodic solutions for this class equations.     

一类p-Laplacian方程非零解的存在性

通过运用变分方法和分析技巧,在超二次条件和非二次条件下获得了p-Laplacian方程Dirichlet边值问题解的存在性结果.

Abstract：

The existence results are obtained for solutions of Dirichlet boundary value problem for a class of p-Lapla-eian equations by using the variational method and analytic technique under the superquadratie condition and the non-quadratic condition.     

一类非线性三阶时滞系统的全局渐近稳定性分析

针对一类非线性三阶时滞系统构造出了一个合理的Lyapunov函数,去除了要求lyapunov函数趋于无穷大这个较强的条件约束,只要求系统正半轨线有界,所得的全局渐近稳定性的充分性结果改进了相关文献的结论.最后给出了例子及仿真说明充分条件的有效性.

Abstract：

In this paper,we construct a better Lyapunov function for the nonlinear third order delay system by onlysupposing that the positive half orbit of the system is bounded.The original strong condition is removed,which demands that the Lyapunov function must trend to infinity.The results have improved the conclusions of relevant literatures.At last,examples are given and simulation is made to show the effectiveness of the sufficient conditions.     

具有竞争的Leslie型捕食者-食饵模型的定性分析

考虑了具有竞争的Leslie型模型.证明了解的最终有界性,和系统在一定条件下的一致持续生存性.研究了平衡点的局部稳定性.通过构建适当的Lyapunov函数,获得了正平衡点全局渐进稳定的充分条件.

Abstract：

In this paper, a competitive Leslie model is proposed. It is proved that the system's solution is ultimately bounded and the system is consistent and sustained under appropriate conditions. The local stability of the equilibria is investigated. By constructing a suitable Lyapunov functional, sufficient conditions are derived for the global stability of the positive equilibrium of the model.     

一个新非自治超混沌四维二次系统及其电路实现

在三维二次混沌系统的基础上增加一个含控制信号的状态变量,组成一个新的非自治超混沌四维二次系统.该系统的基本动力学特性的变化主要依赖于控制信号频率的改变.通过系统的Lyapunov指数谱、分岔图及数值仿真表明,在不同的频率参数下,该系统能够体现周期、拟周期、混沌、超混沌的动力学特性.最后设计了一个模拟电路,进一步验证了其特性.

Abstract：

Based on the three-dimensional quadratic chaos system, this paper constructs a new four-dimensional quadratic non-autonomous hyperchaos system by adding a state variable with the controlling signal.The change in the basic dynamics characters of this system is mainly realized by varying the frequency of the controlling signal. The different chaos dynamics characters of this system such as periodicity, quasi periodicity, chaos and hyperchaos at different frequencies is shown by Lyapunov spectrum , bifurcation diagram and numerical simulation. The results of the experiment are further shown to be consistent with the numerical simulation by designing an analog electronic circuit.     

关于三个问题的混合粘性迭代

在Hilbert空间中,对求解混合平衡问题、非扩张映射不动点问题及单调L-Lipschitz连续映射变分不等式问题解的公共元,引入了由粘性迭代方法确定的迭代序列.在一些参数控制条件下获得了一个强收敛定理.

Abstract：

This paper introduces an iterative sequence for finding a common element of the set of solutions of a mixed equilibrium problem,the set of fixed point problem of nonexpansive mapping and the set of solutions of the variational inequality problem.A strong convergence theorem is obtained under some parameter controlling conditions.     

类具有急慢性阶段和垂直传染的非线性SACS传染病模型

研究一类具有非线性接触率和垂直传染且在急慢性阶段均传染的非线性SACS传染病侍播数学模型动力学性质,确定了各类平衡点存在的条件阈值,讨论了各平衡点的稳定性,并将会在临界值处出现Hopf分支,揭示了急慢性阶段传染对疾病发展趋势的共同影响.

Abstract：

The dynamics of a nonlinear SACS epidemic model with vertical transmission, which has infective force at both acute and chronic stages, is studied. The conditions and thresholds for the existence of various equilibria are established. The stability of equilibria is discussed, and periodic solutions may appear by Hopf bifurcation. The influence of infectivity at acute and chronic stages on the developing trend of the disease is disclosed.     

黎曼流形上弱向量似变分不等式解的存在性

在黎曼流形上分别给出了伪不变凸函数和弱向量似变分不等式的概念.研究这类弱向量似变分不等式和向量优化问题弱有效解之间的关系.利用最大元定理证明了弱向量变分不等式解的存在性,并给出了向量优化问题弱有效解存在的条件.

Abstract：

The definitions of pseudo-invex function and weak vector variation-like inequality on Riemannian manifolds are presented. The relationship between this kind of weak vector variation-like inequalities and the weak efficient solution of vector optimization problems is obtained. By using the maximum element theorem, the existence theorem for weak vector variational-like inequalities defined on Riemannian manifolds is given. Moreover, the conditions for the existence of weak efficient solution to vector optimization problems are presented.