THEORY AND METHOD OF OPTIMAL CONTROL SOLUTION TODYNAMIC SYSTEM PARAMETERS IDENTIFICATION (Ⅰ)──FUNDAMENTAL CONCEPT AND DETERMINISTIC SYSTEM PARAMETERS IDENTIFICATION

IntroductionDynamicsystemidentificationistheinverseproblemofdynamics.Throughtheuseofexperimentaloroperahonalinput-outputdata,modelofdynaITilcsystemcanbeestablishedbysystemidentificationtechnique,andundetCndnedparametersofmodelcanalsobeidenhfied.Ingeneral,dynamicequahonsofsystemareknownPrior,whilesystemidentificahonisjustanundetendnedparametersidentificationproblem.TheseparametersaremodalparameterssuchasfrequenciesandmodeshapesorstrUctUralparameterssuchasdampingandstiffness.T'hisisatypical"g…     

THEORY AND ALGORITHM OF OPTIMAL CONTROL SOLUTION TO DYNAMIC SYSTEM PARAMETERS IDENTIFICATION (Ⅱ) ──STOCHASTIC SYSTEM PARAMETERS IDENTIFICATION AND APPLICATION EXAMPLE

Based on the contents Of part (Ⅰ) and stochastic optimal control theory, the concept of optimal control solution to parameters identification of stochastic dynamic system is discussed at first. For the completeness of the theory developed in this paper and part (Ⅰ), then the procedure of establishing HamiltonJacobi-Bellman (HJB) equations of parameters identification problem is presented.And then, parameters identification algorithm of stochastic dynamic system is introduced. At last, an application example-local nonlinear parameters identification of dynamic system is presented.     

THEORY AND METHOD OF OPTIMAL CONTROL SOLUTION TO DYNAMIC SYSTEM PARAMETERS IDENTIFICATION (I)──FUNDAMENTAL CONCEPT AND DETERMINISTIC SYSTEM PARAMETERS IDENTIFICATION

Based on the concept of optimal control solution to dynamic system parameters identification and the optimal control theory of deterministic system, dynamics system parameters identification problem is brought into correspondence with optimal control problem. Then the theory and algorithm of optimal control are introduced into the study of dynamic system parameters identification. According to the theory of Hamilton-Jacobi-Bellman (HJB) equations' solution, the existence and uniqueness of optimal control solution to dynamic system parameters identification are resolved in this paper. At last the parameters identification algorithm of determi-nistic dynamic system is presented also based on above mentioned theory and concept. Project supported by the National, Defence Science and Technology Foundation (A966000-50) and the Across Century Scientist Foundation from the State Education Commission of China     

THE HAMILTONIAN SYSTEM AND COMPLETENESS OF SYMPLECTIC ORTHOGONAL SYSTEM

I.IntroductionThemethodofseparationofvariablesisimportanttosolvethesoluti0n0fprobIem0fmathematicalphysics,butmanyproblen1sofmathematicalphysicscannotseparatet'ariab1es,thereforeitrestrictstheranget0appIicatemethodofseparationofvariable.Inthepaperlll,Zhong…     

TURBULENT COHERENT STRUCTURE AND DYNAMIC SYSTEM

The main difficulties in the study of turbulence via dynamic system lie in how to relatecontinuum systems of infinite dimension with dynamic system in low dimension space andhow to depict its special structure.In this paper,we’ll give a comprehensive review onvarious methods to describe complex systems in low dimension space and new approaches tothe resolution of turbulence problems.     

GENERALIZED VARIATIONAL PRINCIPLES WITH SEVERAL ARBITRARY PARAMETERS AND THE VARIABLE SUBSTITUTION AND MULTIPLIER METHOD

The functional transformations of variational principles in elasticity are classified asthree patterns:Ⅰ relaxation pattern,Ⅱ augmented pattern and Ⅲ equivalent pattern.On the basis of pattern Ⅲ,the generalized variational principles with several arbitraryparameters are formulated and their functionals are defined They are:the generalizedprinciple of single variable u with several parameters,the generalized principle of twovariables u,σ with several parameters,the generalized principle of two variables u,εwith several parameters,and the generalized principle of three veriables u,ε.σ withseveral parameters.From these principles,a series of new forms of equivalent functionalscan be obtained.When the values of these parameters are properly chosen.a series of finiteelement models can be formulated.In this paper,the question of losing effectiveness for Lagrange multiplier method isalso discussed.In order to“recover”effectiveness for multiplier method,a modifiedmethod,namely,the variable substitutio     

SYSTEM OF VECTOR QUASI-EQUILIBRIUM PROBLEMS AND ITS APPLICATIONS

A new system of vector quasi-equilibrium problems is introduced and its existence of solution is proved. As applications, some existence results of weak Pareto equilibrium for both constrained multicriteria games and multicriteria games without constrained correspondences are also shown.     

MINIMAL POLYNOMIAL MATRIX AND LINEAR MULTIVARIABLE SYSTEM(Ⅱ)

part(Ⅰ) of this work is on the theory of minimal polynomial matrix and Part(Ⅱ)is onthe applications of this theory to linear multivarible systeme.In I of this part,using the theory to Part(Ⅰ),some results about input part of a linearmultivarble system are discussed in detail and in Ⅱ,using duality properties,the conceptsabout row n.p.m.and row generating system,etc.are given. and some results about outputpart of linear multivariable system are discussed, too.In Ⅲ,we discuss the approach whichcan give the polynomial model with less dimension from the state-space model and in Ⅳ wediscuss tha inverse of the problem to give the state-space model from the polynomial model.Some interesting examples are given to explain the theory and the approach.     

FORM INVARIANCE AND LIE SYMMETRY OF THE GENERALIZED HAMILTONIAN SYSTEM

The form invariance and the Lie symmetry of the generalized Hamiltonian system are studied. Firstly, de?nitions and criteria of the form invariance and the Lie symmetry of the system are given. Next, the relation between the form invariance an…     

A PROBABILITY AND INTERVAL HYBRID STRUCTURAL RELIABILITY ANALYSIS METHOD CONSIDERING PARAMETERS’ CORRELATION

提出了一种考虑相关性的概率-区间混合不确定性模型及结构可靠性分析方法,能够处理变量之间具有相关性的混合可靠性分析问题. 分别针对概率变量,概率区间变量及区间变量定义了相关角的概念,用以定量描述变量之间的相关性;通过仿射坐标,将相关变量转换为独立变量;给出了其可靠性分析模型,并构建了一高效求解方法获得其可靠性指标和失效概率区间;最后通过分析两个数值算例,验证了方法的有效性.     

GENERALIZED VARIATIONAL DATA ASSIMILATION METHOD AND NUMERICAL EXPERIMENT FOR NON-DIFFERENTIAL SYSTEM

The generalized variational data assimilation for non-differential dynamical systems is studied. There is no tangent linear model for non-differential systems and thus the general adjoint model can not be derived in the traditional way. The weak form of the original system was introduced, and then the generalized adjoint model was derived. The generalized variational data assimilation methods were developed for non-differential low dimensional system and non-differential high dimensional system with global and local observations. Furthermore, ideas in inverse problems are introduced to 4DVAR ( Fourdimensional variational ) of non-differential partial differential system with local observations.     

NUMERICAL METHOD BASED ON HAMILTON SYSTEM AND SYMPLECTIC ALGORITHM TO DIFFERENTIAL GAMES

The resolution of differential games often concerns the difficult problem of two points border value (TPBV), then ascribe linear quadratic differential game to Hamilton system. To Hamilton system, the algorithm of symplectic geometry has the merits of being able to copy the dynamic structure of Hamilton system and keep the measure of phase plane. From the viewpoint of Hamilton system, the symplectic characters of linear quadratic differential game were probed; as a try, Symplectic-Runge-Kutta algorithm was presented for the resolution of infinite horizon linear quadratic differential game. An example of numerical calculation was given, and the result can illuminate the feasibility of this method. At the same time, it embodies the fine conservation characteristics of symplectic algorithm to system energy.     

THE STUDY ON A KIND OF CONTROL SYSTEM WITH NONLINEAR PARABOLIC DISTRIBUTED PARAMETERS

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅａｃｔｉｖｉｔｉｅｓｓｕｃｈａｓｔｈｅａｅｒｏｓｐａｃｅｅｎｇｉｎｅｅｒｉｎｇｈｅａｔｐｒｏｔｅｃｔｉｏｎ[1,2 ],ｔｈｅｌａｒｇｅ＿ｓｃａｌｅｃｏｎｃｒｅｔｅｐｏｕｒｉｎｇ ,ｔｈｅｃｈｅｍｉｃａｌｐｒｏｄｕｃｔｉｏｎ ,ｔｈｅｐｏｗｄｅｒｍｅｔａｌｌｕｒｇｙａｎｄｔｈｅｆｉｒｅｓａｆｅｔｙｅｎｇｉｎｅｅｒｉｎｇ[3,4],ｔｈｅｒｅｉｓｏｎｅｋｉｎｄｏｆｎｏｎｌｉｎｅａｒｐａｒａｂｏｌｉｃｄｉｓｔｒｉｂｕｔｅｄｐａｒａｍｅｔｅｒｃｏｎｔｒｏｌｓｙｓｔｅｍｗｉｔｈｍｏｖｉ…     

SYSTEM OF COINCIDENCE THEOREMS IN PRODUCT TOPOLOGICAL SPACES AND APPLICATIONS (Ⅰ)

A new notion of finite continuous topological space (in short, FC-space) with out convexity structure was introduced. A new continuous selection theorem was established in FC-spaces. By applying the continuous selection theorem, some new coincidence theorems for two families of set-valued mappings defined on product space of noncompact FC-spaces are proved under much weak assumptions. These results generalize many known results in recent literature. Some applications will be given in a follow-up paper.     

MODEL OF CENTRIFUGAL EFFECT AND ATTITUDE MANEUVER STABILITY OF A COUPLED RIGID-FLEXIBLE SYSTEM

IntroductionThedynamicandcontrolofcoupledrigid_flexiblesystemisaleading_edgeresearchsubjectthathasdrawnextensiveattentionfromtheacademiccommunityintheworld[1].TheresearchconductedbyKaneetal.in 1 987[2 ]suggestedthat,thetraditionalmodelapplyingstructuraldynamicsassumptionaboutelasticdeformationindiscriminately[3,4 ],ineffect,hasneglectedtheso_called“dynamicstiffening”effectresultedfromcoupledrigid_flexiblesystem .Therefore ,itisofparticularimportancetoresearchtheactionofcoupledrigid_flexibles…     

ON THE UNIFICATION OF THE HAMILTON PRINCIPLES IN NONHOLONOMIC SYSTEM AND IN HOLONOMIC SYSTEM

ＯＮＴＨＥＵＮＩＦＩＣＡＴＩＯＮＯＦＴＨＥＨＡＭＩＬＴＯＮＰＲＩＮＣＩＰＬＥＳＩＮＮＯＮＨＯＬＯＮＯＭＩＣＳＹＳＴＥＭＡＮＤＩＮＨＯＬＯＮＯＭＩＣＳＹＳＴＥＭ（梁立孚）（韦扬）ＯＮＴＨＥＵＮＩＦＩＣＡＴＩＯＮＯＦＴＨＥＨＡＭＩＬＴＯＮＰＲＩＮＣＩＰＬ...     

NANOINDENTATION OF THIN-FILM-SUBSTRATE SYSTEM： DETERMINATION OF FILM HARDNESS AND YOUNG’S MODULUS

In the present paper, the hardness and Young‘s modulus of film-substrate systems are determined by means of nanoindentation experiments and modified models. Aluminum film and two kinds of substrates, i.e. glass and silicon, are studied. Nanoindentation XP Ⅱ and continuous stiffness mode are used during the experiments. In order to avoid the influence of the Oliver and Pharr method used in the experiments, the experiment data are analyzed with the constant Young‘s modulus assumption and the equal hardness assumption. The volume fraction model (CZ model) proposed by Fabes et al. (1992) is used and modified to analyze the measured hardness. The method proposed by Doerner and Nix (DN formula) (1986) is modified to analyze the measured Young‘s modulus. Two kinds of modified empirical formula are used to predict the present experiment results and those in the literature, which include the results of two kinds of systems, i.e., a soft film on a hard substrate and a hard film on a soft substrate. In the modified CZ model, the indentation influence angle, φ, is considered as a relevant physical parameter, which embodies the effects of the indenter tip radius, pile-up or sink-in phenomena and deformation of film and substrate.     

SYSTEM OF COINCIDENCE THEOREMS IN PRODUCT TOPOLOGICAL SPACES AND APPLICATIONS (Ⅱ)

By applying coincidence theorems in part (Ⅰ) for two families of set-valued mappings defined on product space of noncompact FC-spaces in preceding paper, some new existence theorems for system of vector equilibrium problems, system of inequalities and system of minimax theorems were established in FC-spaces. These results generalize some known results in recent literature.     

THEORETICAL MODEL AND NUMERICAL METHOD ON ONLINE IDENTIFICATION OF DYNAMICAL CHARACTERISTICS OF STRUCTURAL SYSTEM （Department of Engineering Mechanics, Southeast University, Nanjing 210096, P.R. China）

An online method of identification of dynamic characteristics only using measured ambient response of structural dynamic system is widely focused on. The Ibrahim and ARMA ( AutoRegressive Moving Average ) methods are basic identification methods. A model on dynamic system suffered by random ambient excitation was researched into, and a subspace decomposition methodwas introduced. Robustness and effectiveness of this approach on identification of vibration characteristics are demonstrated on numerical experiment.     

DIFFERENCE DISCRETE SYSTEM OF EULER-BEAM WITH ARBITRARY SUPPORTS AND SIGN-OSCILLATORY PROPERTY OF STIFFNESS MATRICES

The difference discrete system of Euler-beam with arbitrary supports was constructed by using the two order central difference formulas. This system is equivalent to the spring-mass-rigidrod model. By using the theory of oscillatory matrix, the sign-oscillatory property of stiffness matrices of this system was proved, and the necessary and sufficient condition for the system to be positive was obtained completely.