• 제목/요약/키워드: Ordinary Differential Equations

검색결과 344건 처리시간 0.026초

ERROR ANALYSIS OF FINITE ELEMENT APPROXIMATION OF A STEFAN PROBLEM WITH NONLINEAR FREE BOUNDARY CONDITION

  • Lee H.Y.
    • Journal of applied mathematics & informatics
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    • 제22권1_2호
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    • pp.223-235
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    • 2006
  • By applying the Landau-type transformation, we transform a Stefan problem with nonlinear free boundary condition into a system consisting of a parabolic equation and the ordinary differential equations. Fully discrete finite element method is developed to approximate the solution of a system of a parabolic equation and the ordinary differential equations. We derive optimal orders of convergence of fully discrete approximations in $L_2,\;H^1$ and $H^2$ normed spaces.

A NUMERICAL METHOD FOR SINGULARLY PERTURBED SYSTEM OF SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS OF CONVECTION DIFFUSION TYPE WITH A DISCONTINUOUS SOURCE TERM

  • Tamilselvan, A.;Ramanujam, N.
    • Journal of applied mathematics & informatics
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    • 제27권5_6호
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    • pp.1279-1292
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    • 2009
  • In this paper, a numerical method that uses standard finite difference scheme defined on Shishkin mesh for a weakly coupled system of two singularly perturbed convection-diffusion second order ordinary differential equations with a discontinuous source term is presented. An error estimate is derived to show that the method is uniformly convergent with respect to the singular perturbation parameter. Numerical results are presented to illustrate the theoretical results.

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Hinged-clamped 보의 확률적 응답특성 (Stochastic Response of a Hinged-Clamped Beam)

  • 조덕상
    • 한국산업융합학회 논문집
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    • 제3권1호
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    • pp.43-51
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    • 2000
  • The response statistics of a hinged-clamped beam under broad-band random excitation is investigated. The random excitation is applied at the nodal point of the second mode. By using Galerkin's method the governing equation is reduced to a system of nonautonomous nonlinear ordinary differential equations. A method based upon the Markov vector approach is used to generate a general first-order differential equation in the dynamic moment of response coordinates. By means of the Gaussian and non-Gaussian closure methods the dynamic moment equations for the random responses of the system are reduced to a system of autonomous ordinary differential equations. The case of two mode interaction is considered in order to compare it with the case of three mode interaction. The analytical results for two and three mode interactions are also compared with results obtained by Monte Carlo simulation.

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RADIATION EFFECTS ON MHD BOUNDARY LAYER FLOW OF LIQUID METAL OVER A POROUS STRETCHING SURFACE IN POROUS MEDIUM WITH HEAT GENERATION

  • Venkateswarlu, M.;Reddy, G. Venkata Ramana;Lakshmi, D. Venkata
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제19권1호
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    • pp.83-102
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    • 2015
  • The present paper analyses the radiation effects of mass transfer on steady nonlinear MHD boundary layer flow of a viscous incompressible fluid over a nonlinear porous stretching surface in a porous medium in presence of heat generation. The liquid metal is assumed to be gray, emitting, and absorbing but non-scattering medium. Governing nonlinear partial differential equations are transformed to nonlinear ordinary differential equations by utilizing suitable similarity transformation. The resulting nonlinear ordinary differential equations are solved numerically using Runge-Kutta fourth order method along with shooting technique. Comparison with previously published work is obtained and good agreement is found. The effects of various governing parameters on the liquid metal fluid dimensionless velocity, dimensionless temperature, dimensionless concentration, skin-friction coefficient, Nusselt number and Sherwood number are discussed with the aid of graphs.

Elasticity solution of multi-layered shallow cylindrical panels subjected to dynamic loading

  • Shakeri, M.;Eslami, M.R.;Alibiglu, A.
    • Steel and Composite Structures
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    • 제2권3호
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    • pp.195-208
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    • 2002
  • Elasticity solutions to the boundary-value problems of dynamic response under transverse asymmetric load of cross-ply shallow cylindrical panels are presented. The shell panel is simply supported along all four sides and has finite length. The highly coupled partial differential equations are reduced to ordinary differential equations with constant coefficients by means of trigonometric function expansion in the circumferential and axial directions. The resulting ordinary differential equations are solved by Galerkin finite element method. Numerical examples are presented for two (0/90 deg.) and three (0/90/0 deg.) laminations under dynamic loading.

A NEW METHOD FOR SOLVING THE NONLINEAR SECOND-ORDER BOUNDARY VALUE DIFFERENTIAL EQUATIONS

  • Effati, S.;Kamyad, A.V.;Farahi, M.H.
    • Journal of applied mathematics & informatics
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    • 제7권1호
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    • pp.183-193
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    • 2000
  • In this paper we use measure theory to solve a wide range of second-order boundary value ordinary differential equations. First, we transform the problem to a first order system of ordinary differential equations(ODE's)and then define an optimization problem related to it. The new problem in modified into one consisting of the minimization of a linear functional over a set of Radon measures; the optimal measure is then approximated by a finite combination of atomic measures and the problem converted approximatly to a finite-dimensional linear programming problem. The solution to this problem is used to construct the approximate solution of the original problem. Finally we get the error functional E(we define in this paper) for the approximate solution of the ODE's problem.

Approximating Coupled Solutions of Coupled PBVPs of Non-linear First Order Ordinary Differential Equations

  • Dhage, Bapurao Chandrabhan
    • Kyungpook Mathematical Journal
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    • 제56권1호
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    • pp.221-233
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    • 2016
  • The present paper proposes a new monotone iteration method for existence as well as approximation of the coupled solutions for a coupled periodic boundary value problem of first order ordinary nonlinear differential equations. A new hybrid coupled fixed point theorem involving the Dhage iteration principle is proved in a partially ordered normed linear space and applied to the coupled periodic boundary value problems for proving the main existence and approximation results of this paper. An algorithm for the coupled solutions is developed and it is shown that the sequences of successive approximations defined in a certain way converge monotonically to the coupled solutions of the related differential equations under some suitable mixed hybrid conditions. A numerical example is also indicated to illustrate the abstract theory developed in the paper.

EIGENVALUE APPROACH FOR UNSTEADY FRICTION WATER HAMMER MODEL

  • Jung Bong Seog;Karney Bryan W.
    • Water Engineering Research
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    • 제5권4호
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    • pp.177-183
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    • 2004
  • This paper introduces an eigenvalue method of transforming the hyperbolic partial differential equations of a particular unsteady friction water hammer model into characteristic form. This method is based on the solution of the corresponding one-dimensional Riemann problem that transforms hyperbolic quasi-linear equations into ordinary differential equations along the characteristic directions, which in this case arises as the eigenvalues of the system. A mathematical justification and generalization of the eigenvalues method is provided and this approach is compared to the traditional characteristic method.

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