EXISTENCE OF SOLUTIONS FOR A CLASS OF SYSTEMS GOVERNED BY NONLINEAR DIFFERENTIAL INCLUSIONS

ＥＸＩＳＴＥＮＣＥＯＦＳＯＬＵＴＩＯＮＳＦＯＲＡＣＬＡＳＳＯＦＳＹＳＴＥＭＳＧＯＶＥＲＮＥＤＢＹＮＯＮＬＩＮＥＡＲＤＩＦＦＥＲＥＮＴＩＡＬＩＮＣＬＵＳＩＯＮＳ￥ＸＩＡＮＧＸｉａｏｌｉｎｇ；ＷＡＮＧＹｕａｎｄｉ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔ...     

DESIGN OF NONLINEAR OBSERVERS

ＤＥＳＩＧＮＯＦＮＯＮＬＩＮＥＡＲＯＢＳＥＲＶＥＲＳ￥ＺＨＥＮＧＹｕｆａｎ；ＣＨＥＮＳｈｕｚｈｏｎｇ（ＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓＲｅｓｅａｒｃｈＬａｂｏｒｕｔｏｒｙ，ＥａｓｔＣｈｉｎａＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｓｈａｎｇｈａｉ２００...     

CONTINUATION METHOD OF NONLINEAR INTEGRAL EQUATIONS

ＣＯＮＴＩＮＵＡＴＩＯＮＭＥＴＨＯＤＯＦＮＯＮＬＩＮＥＡＲＩＮＴＥＧＲＡＬＥＱＵＡＴＩＯＮＳ￥ＹＡＮＧＦｅｎｇｈａｎｇ；ＳＵＮＪｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＴｉａｎｊｉｎＵｎｉｖｅｒｓｉｔｙ，Ｔｉａｎｉｉｎ３０００７２，Ｃ...     

WU-RITT''''S METHOD FOR NONLINEAR CONTROL SYSTEMS

ＷＵ－ＲＩＴＴ＇ＳＭＥＴＨＯＤＦＯＲＮＯＮＬＩＮＥＡＲＣＯＮＴＲＯＬＳＹＳＴＥＭＳ￥ＬＩＳｈｕｒｏｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＳｙｓｔｅｍｓＳｃｉｅｎｃｅ，ＡｃａｄｅｍｉａＳｉｎｉｃａ，Ｂｅｉｊｉｎｇ１０００８０，Ｃｈｉｎａ）Ａｂｓｔｒａｃｔ：Ｔｈｉ...     

ON LOCAL STABILIZATION OF NONLINEAR CONTROL SYSTEMS

Based on the notion of maximal absolute observability and its normalforms,a new method for studying the local stabilization for a kind of nonlinearcontrol systems is established.Different from the previous results given by Byrnes-Isitori and others,this new method can deal with more general systems,and hasmuch simpler way to prove the stabilization conditions and to design the feedbacklaws.     

大型非线性系统的试验选优方法

本文提出了大型非线性系统的试验选优方法，其同现行的大系统优化方法相比，优化工作量小、优化范围广，在某种意义上，传统的大系统“分解聚合”方法为该方法的一个特例——全面试验选优方法．     

A NONLINEAR POPULATION EVOLUTION SYSTEM

A nonlinear age-dependent population model,which allows for consideration of theeffects of crowding and resource limitation,is presented.The basic properties of solution,such asexistence,positivity,uniqueness,and ultimate behavior,are discussed.Also,the condition of stabilityand controll-ability of the nonlinear population system is obtained.     

ON A LINEAR EQUATIONS METHOD OF NONLINEAR POLYNOMIAL EQUATIONS-SOLVING

A method for solving nonlinear polynomial equations is given which avoids theappearance of redundant factors as in the previous characteristic set method developed bythe present author. The new method seems thus to be of much higher efficiency than theprevious one. It has the further advantage that numerical data may be inserted at willeither at the outset or during the procedure so far removal of factors by divisions may beavoided.     

A MULTISTEP CHARACTERISTIC FINITE DIFFERENCE METHOD FOR TWO-DIMENSIONAL NONLINEAR CONVECTION-DIFFUSION PROBLEMS

1.IntroductionItiswellknowthattheconvection-dictionproblemsareakindofveryimportalprob-lems,particularlylthenonlinearconvection-diffusionproblexns.Inthepaper[1],asinglestepcharacteristicflutedmerencemethodisgivenforsolvingtwcadimensionalnonlinearconvection-dilhaionproblemswiththeconvectivecoefficientsdominating.HereweshallgiveamultistepcharactersticamrencemethodbasedonthelinearandquadraticinterpolationsforsolvingtwcadAnensionalnonlinearconvection-~ionproblemsinordertoincreasetheaccuracyofapprot…     

DISTURBANCE ATTENUATION FOR UNCERTAIN NONLINEAR CASCADED SYSTEMS

In present paper, the disturbance attenuation problem of uncertain nonlinear cascaded systems is studied. Based on the adding one power integrator technique and recursive design, a feedback controller that solves the disturbance attenuation problem is constructed for uncertain nonlinear cascaded systems with internal stability.     

AN SQP METHOD BASED ON SMOOTHING PENALTY FUNCTION FOR NONLINEAR OPTIMIZATION WITH INEQUALITY CONSTRAINT

1 IntroductionIn tabs paper, we consider the following nonlinear optbostion problem:where j: Re - R, g: Re - Re are continuously ~ntiable functinns. SoP method forproblem (1) generates a sequence of points which converges to a K--T point of problem (1)through the following iterate formulaxk 1 = x* adds (2)adhere da is the solution of the following quadratic Prograrxuning problemin which Bh is a sylnlnetric positive deflate lllatris and A* is a stepsise obtained by some lineseaxch to redu…     

A discontinuous Galerkin method combined with mixed finite element for seawater intrusion problem

<正> Seawater intrusion problem is considered in this paper.Its mathematical model is anonlinear coupled system of partial differential equations with initial boundary problem.It consistsof the water head equation and the salt concentration equation.A combined method is developedto approximate the water head equation by mixed finite element method and concentration equationby discontinuous Galerkin method.The scheme is continuous in time and optimal order estimates inH~1-norm and L~2-norm are derived for the errors.     

A SINGLESTEP CHARACTERISTIC FINITE DIFFERENCE METHOD FOR TWO-DIMENSIO NALNON LINEAR CONVECTION-DIFFUSIONPROBLEMS

1.IntroductionThenonlinearconvection-diffusionproblemsareakindofveryimportantproblemssuchastheundergroundpercolation,air--pollution,fluidmechanicsmodelingetc.Thenumericalmethodsforsolvingthelinearproblemswiththeconvectivecoefficientsdominating,whicharethecharacteristicfiniteelementandcharacteristicfinitedifferencemethods,aregivenbyJ.DouglasandT.F.Russellin[1]andfurtherdevelopmentin[2]and[3],etc.ButtheconvergenceofmethodsneedstherestrictiveassumptionAt=O(h).Inpracticeonewouldliketotakebigger…     

低信噪比图象边缘提取的非线性方法

本文介绍了被强噪声干扰的图象的边缘提取问题。作者提出把大窗口去噪性能强,小窗口提取边缘性能好的优势相结合的思想,采取大窗口滤波,小窗口中用非线性的方法求二阶导数过零点的步骤。文中还提出一种噪声引导的阈值确定准则,以此阈值分割图象。在大窗口滤波中,本文提出用“二维卷积等于一维级联”的技术压缩滤波器的贮存空间,使得贮存空间大为减小。本文最后对这种方法进行了性能评价。     

具有输出限幅特性的非线性系统数学模型建立方法

对于具有线性—限幅特性的非线性系统,在线性和非线性部分之间的任何信息都不知道的情况下,利用频谱分折的方法,可以得到线性和非线性部分的全部参数,并对限幅特性进行确认性检验。本文给出了识别全部参数的详细方法和步骤,最后给出了识别例题。     

High accuracy analysis of the finite element method for nonlinear viscoelastic wave equations with nonlinear boundary conditions

The standard finite elements of degree p over the rectangular meshes are applied to solve a kind of nonlinear viscoelastic wave equations with nonlinear boundary conditions, and the superclose property of the continuous Galerkin approximation is derived without using the nonclassical elliptic projection of the exact solution of the model problem. The global superconvergence of one order higher than the traditional error estimate is also obtained through the postprocessing technique.     

ON THE NUMBER OF FIXED POINTS OF NONLINEAR OPERATORS AND APPLICATIONS

In this paper, the famous Amann three-solution theorem is generalized. Multiplicity question of fixed points for nonlinear operators via two coupled parallel sub-super solutions is studied. Under suitable conditions, the existence of at least six distinct fixed points of nonlinear operators is proved. The theoretical results are then applied to nonlinear system of Hammerstein integral equations.     

AN EXISTENCE THEOREM FOR RADIAL POSITIVE SOLUTIONS OF NONLINEAR DEGENERATE ELLIPTIC EQUATIONS

ＡＮＥＸＩＳＴＥＮＣＥＴＨＥＯＲＥＭＦＯＲＲＡＤＩＡＬＰＯＳＩＴＩＶＥＳＯＬＵＴＩＯＮＳＯＦＮＯＮＬＩＮＥＡＲＤＥＧＥＮＥＲＡＴＥＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮＳＬＩＵＨａｉｌｉａｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＨｅｎａｎＮｏ...     

BOUNDARY LAYER ESTIMATION OF NONLINEAR ELLIPTIC EQUATION

ＢＯＵＮＤＡＲＹＬＡＹＥＲＥＳＴＩＭＡＴＩＯＮＯＦＮＯＮＬＩＮＥＡＲＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮＨＥＣｈｅｎｇ；ＺＨＡＮＧＷｅＩｔａｏ（ＩｎｓｔｉｔｕｔｅｏｆＳｙｓｔｅｍｓＳｃｉｅｎｃｅ，ＡｃａｄｅｍｉａＳｉｌｉｃａ，Ｂｅｉｊｉｎｇ１０００８０，...     

ABSOLUTE STABILITY OF GENERAL LURIE DISCRETE NONLINEAR CONTROL SYSTEMS

1 IntroductionUp to now, there are many results about abso1ute stability for Lurie discrete controlsystems{'--'l. Some sufficient conditions and necessary and sufficient conditions of absolutestability are obtained. But there are a few resuIts about gener…