非线性控制系统的梯度扩张的能达性

研究了仿射非线性控制系统的梯度扩张系统.利用非线性控制系统的微分几何理论,通过计算梯度扩张系统的输出函数沿着输入向量场和系统向量场的李导数,讨论仿射非线性控制系统的梯度扩张系统的能达性分布,研究了非线性控制系统和它的梯度扩张系统的能达性之间的关系,证明了如果梯度扩张系统是能达的,则原非线性控制系统也是能达的.     

几种特殊曲面上的测地线

具体刻画了柱面、锥面、旋转曲面上测地线的几何特征,所得结果一方面匡正了某些文献关于锥面上测地线的错误断言,一方面推广了现有文献关于旋转曲面上测地线几何性质的描述.     

关于一类三重积分的简便求法

关于一类三重积分的简便求法武家华（合肥经济技术学院）众所周知，当积分区域由椭球面、球面、柱面、园锥面或旋转抛物面等曲面所围成时，利用柱面坐标或球面坐标计算三重积分较容易。笔者在教学过程中发现，若积分区域同上，被积函数县羊千。的函都．采佣盲色也拣系．化...     

辛映射与Hamilton控制系统

给定等价辛流形 ,即辛同态或形变等价的辛流形 ,研究了建立在这些辛流形上的Hamilton控制系统之间的一些性质的联系 ,诸如 (局部 )能观测性 ,强可接近性 ,(拟 )极小性等 .而且 ,利用Cort啨ｓ介绍的 (弱 )外等价系统的概念 ,给出使得两个Hamilton控制系统是辛同态的一个充分条件     

滞后控制系统的完全能控性、毕竟能控性、最终能控性和拟能控性

讨论时滞控制系统的能控性 .指出与无时滞系统不同的是 ,该类系统的能控性与终点时刻有一定的关系 .由此给出一系列与终点时刻有关的能控性 ,即完全能控性、毕竟能控性、最终能控性等 ,并得到一些判定定理 .     

非零势能的耗散力学控制系统的位形能控性

在拉格朗日力学控制系统的仿射联络框架下,基于Sussmann对有限维流形上一般仿射非线性控制系统的能控性讨论,将简单力学控制系统短时间局部位形能控的一个可计算的充分条件推广到迷向耗散的系统上,并给出系统是平衡点能控的一个充分条件,其中,系统的拉格朗日函数为动能减势能A·D2在问题的讨论中,系统的能控李代数的向量场李括号运算,以及与系统位形流形的Levi-Civita联络相关的对称积起了重要作用．尽管势能项会使系统的位形能控性讨论复杂化,但Liouville向量场又简化了系统的能控李代数计算．     

一类非线性chemotaxis系统的局部零能控性

本文研究了一类非线性chemotaxis系统的能控性问题.利用这类线性化结合不动点的方法,获得了非线性系统的局部零能控性结果,推广了非线性抛物-椭圆型方程能控性的结果.     

非线性中立型控制系统函数能控性

本文讨论形如的非线性中立型控制系统函数能控性．给出该类系统的函数能控性和零函数能控性的判定定理．所得结果在实际系统的设计、分析等方面是非常实用的．     

关于曲线族产生曲面的理论证明的一点补充——多项式的结式在几何上的一个应用

在空间解析几何中,我们把柱面,锥面和旋转曲面看成是动曲线的轨迹,来建立这几类特殊曲面的方程,例如,把柱面看成是与空间定曲线(准线)相交且和定方向(母线方向)平行的动直线的轨迹。建立柱面方程的步骤是先写出满足条件的动直线的方程——含有参数的直线族方程,然后从     

若干特殊曲面上均匀投点的Von Neumann抽样技巧

木文给出了若干特殊曲面上均匀投点的冯、诺依曼抽样技巧的原理。据此,我们得到了在n维球面、n维锥面、n维环域上均匀投点的冯、诺依曼抽样方法,所得结果在蒙特卡洛计算中具有实用价值。文中提供的方法对获得其它一些特殊区域(譬如,椭球面,椭球体,柱面,空心柱体等)上的均匀投点仍然是适用的。     

Stabilization of stationary affine control systems with discrete time

We obtain new sufficient conditions for the local and global asymptotic stabilization of the zero solution of a nonlinear affine control system with discrete time and with constant coefficients by a continuous state feedback. We assume that the zero solution of the free system is Lyapunov stable. For systems with linear drift, we construct a bounded control in the problem of global asymptotic state and output stabilization. Corollaries for bilinear systems are obtained.     

Asymptotic bifurcation points, and global bifurcation of nonlinear operators and its applications

Using the cone theory and lattice structure, we discuss the existence of asymptotic bifurcation points and the global bifurcation of nonlinear operators which are not assumed to be cone mappings and may not be Frechet differentiable at points at infinity. As an application, the structure of the set of solutions of the superlinear Sturm-Liouville problems is investigated.     

Boundedness, global existence and continuous dependence for nonlinear dynamical systems describing physiologically structured populations

The paper is aimed as a contribution to the general theory of nonlinear infinite dimensional dynamical systems describing interacting physiologically structured populations. We carry out continuation of local solutions to maximal solutions in a functional analytic setting. For maximal solutions we establish global existence via exponential boundedness and by a contraction argument, adapted to derive uniform existence time. Moreover, within the setting of dual Banach spaces, we derive results on continuous dependence with respect to time and initial state.To achieve generality the paper is organized top down, in the way that we first treat abstract nonlinear dynamical systems under very few but rather strong hypotheses and thereafter work our way down towards verifiable assumptions in terms of more basic biological modelling ingredients that guarantee that the high level hypotheses hold.     

A new approach to discretization applied to a continuous, nonlinear, sliding-mode-like control using nonsmooth analysis

This paper introduces a new approach to discretization of nonlinearcontrol laws with a Lipschitz property. The sampling time isdefined as a parameter, which must be selected sufficientlysmall so that the closed-loop system is stable. In contrastto similar results, the stabilizing effect of the control istaken into account. This can result in less conservative constraintson the minimum sampling frequency. The discretization techniquesare explained on a general nonlinear model and applied to thediscretization of a novel nonlinear, robust sliding-mode-likecontrol law. Similar robustness features as for continuous controlare demonstrated. Nonsmooth Lyapunov functions are used forthe discretized sliding-mode-like control introducing cone shapedregions of the state space. One of these cone shaped regionscoincides with a cone shaped layer around the sliding mode definedby the continuous sliding-mode-like control. A stability theoremusing nonsmooth Lyapunov functions is provided.     

A smoothing Newton-type method for generalized nonlinear complementarity problem

By using a new type of smoothing function, we first reformulate the generalized nonlinear complementarity problem over a polyhedral cone as a smoothing system of equations, and then develop a smoothing Newton-type method for solving it. For the proposed method, we obtain its global convergence under milder conditions, and we further establish its local superlinear (quadratic) convergence rate under the BD-regular assumption. Preliminary numerical experiments are also reported in this paper.     

Global Small Solutions to an MHD‐Type System: The Three‐Dimensional Case

In this paper, we consider the global well‐posedness of a three‐dimensional incompressible MHD type system with smooth initial data that is close to some nontrivial steady state. It is a coupled system between the Navier‐Stokes equations and a free transport equation with a universal nonlinear coupling structure. The main difficulty of the proof lies in exploring the dissipative mechanism of the system due to the fact that there is a free transport equation of ? in the coupled equations and only the horizontal derivatives of ? is dissipative with respect to time. To achieve this, we first employ anisotropic Littlewood‐Paley analysis to establish the key L¹(? ⁺ ; Lip(?³)) estimate to the third component of the velocity field. Then we prove the global well‐posedness to this system by the energy method, which depends crucially on the divergence‐free condition of the velocity field. © 2014 Wiley Periodicals, Inc.     

Local‐in‐Time Existence and Uniqueness of Solutions to the Prandtl Equations by Energy Methods

We prove local existence and uniqueness for the two‐dimensional Prandtl system in weighted Sobolev spaces under Oleinik's monotonicity assumption. In particular we do not use the Crocco transform or any change of variables. Our proof is based on a new nonlinear energy estimate for the Prandtl system. This new energy estimate is based on a cancellation property that is valid under the monotonicity assumption. To construct the solution, we use a regularization of the system that preserves this nonlinear structure. This new nonlinear structure may give some insight into the convergence properties from the Navier‐Stokes system to the Euler system when the viscosity goes to 0. © 2015 Wiley Periodicals, Inc.     

Decentralized model-reference adaptive control for a class of uncertain large-scale time-varying delayed systems with series nonlinearities

In this paper, the problem of model-reference adaptive control for large-scale time-varying delayed systems with series nonlinearities is investigated. By applying the theory of variable structure control, we propose an adaptive controller, which is both memoryless and decentralized, to derive the error subsystem between the local model state and plant state to zero. The proposed variable structure control is able to ensure the stability of a sliding manifold of the composite system even though the control input is nonlinear. The main difficulty for handling the effects of interconnected terms is well solved by a new proposed adaptation mechanism. Finally, a numerical example is illustrated to demonstrate the validity of the derived controller.     

Non‐selfsimilar global solutions to a two‐dimensional system of conservation laws

This paper considers the two‐dimensional Riemann problem for a system of conservation laws that models the polymer flooding in an oil reservoir. The initial data are two different constant states separated by a smooth curve. By virtue of a nonlinear coordinate transformation, this problem is converted into another simple one. We then analyze rigorously the expressions of elementary waves. Based on these preparations, we obtain respectively four kinds of non‐selfsimilar global solutions and their corresponding criteria. It is shown that the intermediate state between two elementary waves is no longer a constant state and that the expression of the rarefaction wave is obtained by constructing an inverse function. These are distinctive features of the non‐selfsimilar global solutions. Copyright © 2017 John Wiley & Sons, Ltd.     

Nonmonotone smoothing Broyden-like method for generalized nonlinear complementarity problems

Based on a new symmetrically perturbed smoothing function, the generalized nonlinear complementarity problem defined on a polyhedral cone is reformulated as a system of smoothing equations. Then we suggest a new nonmonotone derivative-free line search and combine it into the smoothing Broyden-like method. The proposed algorithm contains the usual monotone line search as a special case and can overcome the difficult of smoothing Newton methods in solving the smooth equations to some extent. Under mild conditions, we prove that the proposed algorithm has global and local superlinear convergence. Furthermore, the algorithm is locally quadratically convergent under suitable assumptions. Preliminary numerical results are also reported.