• Title/Summary/Keyword: Nonlinear Problem

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NONTRIVIAL SOLUTION FOR THE BIHARMONIC BOUNDARY VALUE PROBLEM WITH SOME NONLINEAR TERM

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • v.21 no.2
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    • pp.117-124
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    • 2013
  • We investigate the existence of weak solutions for the biharmonic boundary value problem with nonlinear term decaying at the origin. We get a theorem which shows the existence of nontrivial solutions for the biharmonic boundary value problem with nonlinear term decaying at the origin. We obtain this result by reducing the biharmonic problem with nonlinear term to the biharmonic problem with bounded nonlinear term and then approaching the variational method and using the mountain pass geometry for the reduced biharmonic problem with bounded nonlinear term.

EXISTENCE OF THE SOLUTIONS FOR THE ELLIPTIC PROBLEM WITH NONLINEAR TERM DECAYING AT THE ORIGIN

  • Choi, Q-Heung;Jung, Tacksun
    • Korean Journal of Mathematics
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    • v.20 no.4
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    • pp.533-540
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    • 2012
  • We consider the multiplicity of the solutions for the elliptic boundary value problem with $C^1$ nonlinear term decaying at the origin. We get a theorem which shows the existence of the nontrivial solution for the elliptic problem with $C^1$ nonlinear term decaying at the origin. We obtain this result by reducing the elliptic problem with the $C^1$ nonlinear term to the el-liptic problem with bounded nonlinear term and then approaching the variational method and using the mountain pass geometry for the reduced the elliptic problem with bounded nonlinear term.

OPTIMIZATION AND IDENTIFICATION FOR THE NONLINEAR HYPERBOLIC SYSTEMS

  • Kang, Yong-Han
    • East Asian mathematical journal
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    • v.16 no.2
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    • pp.317-330
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    • 2000
  • In this paper we consider the optimal control problem of both operators and parameters for nonlinear hyperbolic systems. For the identification problem, we show that for every value of the parameter and operators, the optimal control problem has a solution. Moreover we obtain the necessary conditions of optimality for the optimal control problem on the system.

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ON THE SUBDIFFERENTIAL OF A NONLINEAR COMPLEMENTARITY PROBLEM FUNCTION WITH NONSMOOTH DATA

  • Gao, Yan
    • Journal of applied mathematics & informatics
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    • v.27 no.1_2
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    • pp.335-341
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    • 2009
  • In this paper, a system of nonsmooth equations reformulated from a nonlinear complementarity problem with nonsmooth data is studied. The formulas of some subdifferentials for related functions in this system of nonsmooth equations are developed. The present work can be applied to Newton methods for solving this kind of nonlinear complementarity problem.

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A Nash Solution to Predictive Control Problem for a Class of Nonlinear Systems

  • Ahn, Choon-Ki;Kwon, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.76.5-76
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    • 2002
  • In this paper, we provide a Nash solution to predictive control problem for nonminimum phase singular nonlinear systems. Until now, there is no result on predictive control problem for this class of nonlinear systems. Chen's recent work considered predictive control problem for a class of nonlinear systems with ill-defined relative degree. Since his work is not a result considered in the feedback linearization framework, there is no a result on singular probem in his paper. In contrast to the existing predictive control result, our work considers two main obstacles (singularity and nonminimum phase) in the feedback linearization framework. For a generally formu...

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A NEW APPROACH FOR ASYMPTOTIC STABILITY A SYSTEM OF THE NONLINEAR ORDINARY DIFFERENTIAL EQUATIONS

  • Effati, Sohrab;Nazemi, Ali Reza
    • Journal of applied mathematics & informatics
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    • v.25 no.1_2
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    • pp.231-244
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    • 2007
  • In this paper, we use measure theory for considering asymptotically stable of an autonomous system [1] of first order nonlinear ordinary differential equations(ODE's). First, we define a nonlinear infinite-horizon optimal control problem related to the ODE. Then, by a suitable change of variable, we transform the problem to a finite-horizon nonlinear optimal control problem. Then, the problem is modified into one consisting of the minimization of a linear functional over a set of positive Radon measures. The optimal measure is approximated by a finite combination of atomic measures and the problem converted to a finite-dimensional linear programming problem. The solution to this linear programming problem is used to find a piecewise-constant control, and by using the approximated control signals, we obtain the approximate trajectories and the error functional related to it. Finally the approximated trajectories and error functional is used to for considering asymptotically stable of the original problem.

AN APPROACH FOR SOLVING NONLINEAR PROGRAMMING PROBLEMS

  • Basirzadeh, H.;Kamyad, A.V.;Effati, S.
    • Journal of applied mathematics & informatics
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    • v.9 no.2
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    • pp.717-730
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    • 2002
  • In this paper we use measure theory to solve a wide range of the nonlinear programming problems. First, we transform a nonlinear programming problem to a classical optimal control problem with no restriction on states and controls. The new problem is modified into one consisting of the minimization of a special linear functional over a set of Radon measures; then we obtain an optimal measure corresponding to functional problem which is then approximated by a finite combination of atomic measures and the problem converted approximately to a finite-dimensional linear programming. Then by the solution of the linear programming problem we obtain the approximate optimal control and then, by the solution of the latter problem we obtain an approximate solution for the original problem. Furthermore, we obtain the path from the initial point to the admissible solution.

A time-domain analysis for a nonlinear free-surface problem (시간영역에서의 비선형 자유표면파문제에 대한 수치해석)

  • Kyoung Jo Hyun;Bai Kwang June;Chung Sang Kwon;Kim Do Young
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.381-384
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    • 2002
  • The free surface flow problem has been one of the most interesting and challenging topic in the area of the naval ship hydrodynamics and ocean engineering field. The problem has been treated mainly in the scope of the potential theory and its governing equation is well known Laplace equation. But in general, the exact solution to the problem is very difficult to obtain because of the nonlinearlity of the free surface boundary condition. Thus the linearized free surface problem has been treated often in the past. But as the computational power increases, there is a growing trend to solve the fully nonlinear free surface problem numerically. In the present study, a time-dependent finite element method is developed to solve the problem. The initial-boundary problem is formulated and replaced by an equivalent variational formulation. Specifically, the computations are made for a highly nonlinear flow phenomena behind a transom stern ship and a vertical strut piercing the free surface.

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3-Dimensional Nonlinear Analysis of Low Velocity Impact On Composite Plates (복합재료 평판의 비선형 3차원 저속 충격 해석)

  • 김승조;지국현
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.04a
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    • pp.38-42
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    • 2000
  • In this study, the low velocity impact behavior of the composite laminates has been described by using 3 dimensional nonlinear finite elements. To describe the geometric nonlinearity due to large deformation, the dynamic contact problem is formulated using the exterior penalty finite element method on the base of Total Lagrangian formulation. The incremental decomposition is introduced, and the converged solution is attained by Newton-Raphson Method. The Newmark's constant-acceleration time integration algorithm is used. To make verification of the finite element program developed in this study, the solution of the nonlinear static problem with occurrence of large deformation is compared with ABAQUS, and the solution of the static contact problem with indentation is compared with the Hertz solution. And, the solution of low velocity impact problem for isotropic material is verificated by comparison with that of LS-DYNA3D. Finally the contact force of impact response from the nonlinear analysis are compared with those from the linear analysis.

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