Noise and stability in differential delay equations

We study the stability of linear stochastic differential delay equations in the presence of additive or multiplicative white and colored noise. Using a stochastic analog of the second Liapunov method, sufficient conditions for mean square and stochastic stability are derived.     

ON THE ASYMPTOTIC BEHAVIOR OF HOPFIELD NEURAL NETWORK WITH PERIODIC INPUTS

ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｎｃｅｔｈｅｓｐｅｃｉａｌｓｕｐｅｒｉｏｒｉｔｙｏｆａｒｔｉｆｉｃｉａｌｎｅｕｒａｌｎｅｔｗｏｒｋｓｔｅｃｈｎｏｌｏｇｙｉｎｖａｒｉｏｕｓｅｎｇｉｎｅｅｒｉｎｇｔｅｃｈｎｉｑｕｅｓｆｉｅｌｄｓ,ｓｕｃｈａｓｏｐｔｉｍｉｚａｔｉｏｎ ,ａｓｓｏｃｉａｔｉｖｅｍｅｍｏｒｉｅｓ,ｐａｔｔｅｒｎｒｅｃｏｇｎｉｔｉｏｎ ,ｓｉｇｎａｌｐｒｏｃｅｓｓｉｎｇａｎｄａｕｔｏｍａｔｉｃｃｏｎｔｒｏｌ,ｔｈｅｒｅｈａｓｂｅｅｎｉｎｃｒｅａｓｉｎｇｉｎｔｅｒｅｓｔｉｎｔｈｅｉｎｖｅｓｔｉｇａｔｉ…     

万有引力场中挠性联结双体系统的稳定性与分岔

本文讨论受万有引力矩作用沿圆轨道运动的挠性联结双体系统的平面天平动。讨论其相对轨道坐标系的可能平衡状态。利用Ｌｉａｐｕｎｏｖ直接法分析各平衡状态的稳定性。分析表明，当刚度系数足够小时，平衡状态呆产生分岔和稳定性突变。利用参数空间对系统的全局运动性态作出定性的描述。     

三阶非自治微分方程的不稳定性定理

本文运用构造李雅普诺夫函数的方法，给出了一类三阶非自治微分方程零解不稳定的充分条件．     

线性Volterra系统V泛函的构造及其应用

Ｖ泛函的构造是讨论Ｖｏｌｔｅｒｒａ积分微分系统稳定性的关键．近十年来，不少作者在Ｌｉａｐｕｎｏｖ泛函构造方面作了不少努力，但对一般的线性Ｖｏｌｔｅｒｒａ系统，还是没有构造Ｌｉｓｐｕｎｏｖ泛函通用而有效的方法．本文通过具体求解一个线性偏微分方程的方法来确定Ｖ泛函，得到了更广泛的Ｌｉａｐｕｎｏｖ泛函以及变号Ｖ泛函．同时，利用这些Ｖ泛函对线性Ｖｏｌｔｅｒｒａ系统的实用稳定性与Ｌｉｓｐｕｎｏｖ稳定性作了讨论．     

一类三阶非线性非自治系统解的有界性

本文利用一为三阶非线性自治系统的李雅夫函数,给出了一类三阶非线性非自治系统解有界的充分性准则,推广了文「１－２」的结果。     

Global dynamical behavior of a three-body system with flexible connection in the gravitational field

Summary In this paper, the global behavior of relative equilibrium states of a three-body satellite with flexible connection under the action of the gravitational torque is studied. With geometric method, the conditions of existence of nontrivial solutions to the relative equilibrium equations are determined. By using reduction method and singularity theory, the conditions of occurrence of bifurcation from trivial solutions are derived, which agree with the existence conditions of nontrivial solutions, and the bifurcation is proved to be pitchfork-bifurcation. The Liapunov stability of each equilibrium state is considered, and a stability diagram in terms of system parameters is presented. Received 10 March 1998; accepted for publication 21 July 1998     

Stability of the bicarbonate system in the blood

In this paper, we describe a mathematical model about the reaction-diffusion kinetics of bicarbonate system, which it plays a key role in regulating blood pH. It is very important to know the determinants of blood pH in both experimental and theoretical studies, in order to help to investigate the hidden mechanism of acid-base disorders in the clinical setting. We explore the dynamics of the bicarbonate system under the closed condition. This condition yields that the total amount of carbon dioxide is conserved and the difference in concentrations between anions and cations is conserved. For the stability of the model, we hypothesize that the amount of initial concentrations perturbed around an equilibrium point is less than a certain constant depending on a rate constant. With an application of Liapunov's method, we prove that the model in the form of reaction-diffusion system is globally stable under the hypothesis. We also provide the blood pH profile, which is computed in our model with the experimentally observed rate constants.     

一类三阶非线性系统的全局稳定性

本文运用“类比法”，构造了一类三阶非线性系统的李雅普诺夫函数，从而推出了该系统的零解全局渐近稳定的条件。