• Title/Summary/Keyword: Parabolic Equations

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Free Vibration Analysis of Parabolic Strip Foundations (포물선형 띠기초의 자유진동 해석)

  • Lee, Tae-Eun;Lee, Jong-Kook;Kang, Hee-Jong;Lee, Byoung-Koo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.703-706
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    • 2005
  • Since soil structure interactions are one of the most important subjects in the structural/foundation engineering, much study concerning the soil structure interactions had been carried out. One of typical structures related to the soil structure interactions is the strip foundation which is basically defined as the beam or strip rested on or supported by the soils. At the present time, lack of studies on dynamic problems related to the strip foundations is still found in the literature. From these viewpoint this paper aims to theoretically investigate dynamics of the parabolic strip foundations and also to present the practical engineering data for the design purpose. Differential equations governing the free, out o plane vibrations of such strip foundations are derived, in which effects of the rotatory and torsional inertias and also shear deformation are included although the warping of the cross-section is excluded. Governing differential equations subjected to the boundary conditions of free-free end constraints are numerically solved for obtaining the natural frequencies and mode shapes by using the numerical integration technique and the numerical method of nonlinear equation.

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Numerical Analysis of Nonlinear Effect of Wave on Refraction and Diffraction (파의 굴절 및 회절에 미치는 비선형 효과에 대한 수치해석)

  • 이정규;이종인
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.2 no.1
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    • pp.51-57
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    • 1990
  • Based on second-order Stokes wave and parabolic approximation, a refraction-diffraction model for linear and nonlinear waves is developed. With the assumption that the water depth is slowly varying, the model equation describes the forward scattered wavefield. The parabolic approximation equations account for the combined effects of refraction and diffraction, while the influences of bottom friction, current and wind have been neglected. The model is tested against laboratory experiments for the case of submerged circular shoal, when both refraction and diffraction are equally significant. Based on Boussinesq equations, the parabolic approximation eq. is applied to the propagation of shallow water waves. In the case without currents, the forward diffraction of Cnoidal waves by a straight breakwater is studied numerically. The formation of stem waves along the breakwater and the relation between the stem waves and the incident wave characteristics are discussed. Numerical experiments are carried out using different bottom slopes and different angles of incidence.

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TIME DISCRETIZATION WITH SPATIAL COLLOCATION METHOD FOR A PARABOLIC INTEGRO-DIFFERENTIAL EQUATION WITH A WEAKLY SINGULAR KERNEL

  • Kim Chang-Ho
    • The Pure and Applied Mathematics
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    • v.13 no.1 s.31
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    • pp.19-38
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    • 2006
  • We analyze the spectral collocation approximation for a parabolic partial integrodifferential equations(PIDE) with a weakly singular kernel. The space discretization is based on the spectral collocation method and the time discretization is based on Crank-Nicolson scheme with a graded mesh. We obtain the stability and second order convergence result for fully discrete scheme.

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CONTROLLABILITY OF NONLINEAR DELAY PARABOLIC EQUATIONS UNDER BOUNDARY CONTROL

  • Park, Jong-Yeoul;Kwun, Young-Chel;Jeong, Jin-Mun
    • Journal of the Korean Mathematical Society
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    • v.33 no.2
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    • pp.333-346
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    • 1996
  • Let $A(\zeta, \partial)$ be a second order uniformly elliptic operator $$ A(\zeta, \partial )u = -\sum_{j, k = 1}^{n} \frac{\partial\zeta_i}{\partial}(a_{jk}(\zeta)\frac{\partial\zeta_k}{\partial u}) + \sum_{j = 1}^{n}b_j(\zeta)\frac{\partial\zeta_j}{\partial u} + c(\zeta)u $$ with real, smooth coefficients $a_{j, k}, b_j$, c defined on $\zeta \in \Omega, \Omega$ a bounded domain in $R^n$ with a sufficiently smooth boundary $\Gamma$.

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DOUBLY NONLINEAR PARABOLIC EQUATIONS INVOLVING p-LAPLACIAN OPERATORS VIA TIME-DISCRETIZATION METHOD

  • Shin, Kiyeon;Kang, Sujin
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.6
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    • pp.1179-1192
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    • 2012
  • In this paper, we consider a doubly nonlinear parabolic partial differential equation $\frac{{\partial}{\beta}(u)}{{\partial}t}-{\Delta}_pu+f(x,t,u)=0$ in ${\Omega}{\times}[0,T]$, with Dirichlet boundary condition and initial data given. We prove the existence of a discrete approximate solution by means of the Rothe discretization in time method under some conditions on ${\beta}$, $f$ and $p$.

ERROR ESTIMATES FOR FULLY DISCRETE MIXED DISCONTINUOUS GALERKIN APPROXIMATIONS FOR PARABOLIC PROBLEMS

  • OHM, MI RAY;LEE, HYUN YOUNG;SHIN, JUN YONG
    • East Asian mathematical journal
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    • v.31 no.5
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    • pp.685-693
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    • 2015
  • In this paper, we introduce fully discrete mixed discontinuous Galerkin approximations for parabolic problems. And we analyze the error estimates in $l^{\infty}(L^2)$ norm for the primary variable and the error estimates in the energy norm for the primary variable and the flux variable.

SECOND ORDER GENERALIZED DIFFERENCE METHODS OR ONE DIMENSIONAL PARABOLIC EQUATIONS

  • Jiang, Ziwen;Sun, Jian
    • Journal of applied mathematics & informatics
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    • v.6 no.1
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    • pp.15-30
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    • 1999
  • In this paper the second order semi-discrete and full dis-crete generalized difference schemes for one dimensional parabolic equa-tions are constructed and the optimal order $H^1$ , $L^2$ error estimates and superconvergence results in TEX>$H^1$ are obtained. The results in this paper perfect the theory of generalized difference methods.

Higher Order Parabolic Wave Equations (고차 포물형 파랑 근사식)

  • Seo, Seung-Nam;Lee, Dong-Young
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.3
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    • pp.205-212
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    • 2007
  • Parabolic approximation wave models based on $Pad{\acute{e}}$ approximants are analyzed in order to calculate wave transformation. In this study a $Pad{\acute{e}}(2,2)$ parabolic approximation model is developed to increase the accuracy of computation in comparison with the existing models. Numerical studies on a constant sloping bed show that the new model proves to allow for much more successful treatment of large angles of incidence than is possible using the previously available models.