• Title/Summary/Keyword: Poisson problem

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A DIRECT SOLVER FOR THE LEGENDRE TAU APPROXIMATION FOR THE TWO-DIMENSIONAL POISSON PROBLEM

  • Jun, Se-Ran;Kang, Sung-Kwon;Kwon, Yong-Hoon
    • Journal of applied mathematics & informatics
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    • v.23 no.1_2
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    • pp.25-42
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    • 2007
  • A direct solver for the Legendre tau approximation for the two-dimensional Poisson problem is proposed. Using the factorization of symmetric eigenvalue problem, the algorithm overcomes the weak points of the Schur decomposition and the conventional diagonalization techniques for the Legendre tau approximation. The convergence of the method is proved and numerical results are presented.

A Non-uniform Bound on Matching Problem

  • Teerapabolarn, Kanint;Neammanee, Kritsana
    • Kyungpook Mathematical Journal
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    • v.46 no.4
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    • pp.489-496
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    • 2006
  • The aim of this paper is to use the Stein-Chen method to obtain a non-uniform bound on Poisson approximation in matching problem.

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A Numerical Analysis on the solution of Poisson Equation by Direct Method (직접법을 이용한 Poisson 방정식 수치해법에 관하여)

  • Y.S. Shin;K.P. Rhee
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.3
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    • pp.62-71
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    • 1995
  • In the numerical analysis of incompressible unsteady Navier-stokes equation, large time is required for solving the pressure Poisson equation of the elliptic type at each time step. In this paper, a numerical analysis by the direct method is carried out to solve the pressure Poisson equation and the computing time is analyzed as mesh size increases. The pressure Poisson equation can be transformed to the boundary value problem by the Green theorem. The computing time for the convolution type of the domain integral can be reduced by using F.F.T. and the computing time in the direct method depends entirely on obtaining the solution of the boundary value problem. The numerical analysis on the known solutions is carried out and compared for the verification of the direct method. And the numerical analysis on the body boundary and domain decomposition problem are carried out with the computing time less than O($n^{3}$) in the (n.n) mesh.

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Image Reconstruction Using Poisson Model Screened from Image Gradient (이미지 기울기에서 선별된 포아송 모델을 이용한 이미지 재구성)

  • Kim, Yong-Gil
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.2
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    • pp.117-123
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    • 2018
  • In this study, we suggest a fast image reconstruction scheme using Poisson equation from image gradient domain. In this approach, using the Poisson equation, a guided vector field is created by employing source and target images within a selected region at the first step. Next, the guided vector is used in generating the result image. We analyze the problem of reconstructing a two-dimensional function that approximates a set of desired gradients and a data term. The joined data and gradients are able to work like modifying the image gradients while staying close to the original image. Starting with this formulation, we have a screened Poisson equation known in physics. This equation leads to an efficient solution to the problem in FFT domain. It represents the spatial filters that solve the two-dimensional screened Poisson model and shows gradient scaling to be a well-defined sharpen filter that generalizes Laplace sharpening. We demonstrate the results using a discrete cosine transformation based this Poisson model.

ANALYSIS OF A FOURTH ORDER SCHEME AND APPLICATION OF LOCAL DEFECT CORRECTION METHOD

  • Abbas, Ali
    • Journal of applied mathematics & informatics
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    • v.32 no.3_4
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    • pp.511-527
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    • 2014
  • This paper provides a new application similar to the Local Defect Correction (LDC) technique to solve Poisson problem -u"(x) = f(x) with Dirichlet boundary conditions. The exact solution is supposed to have high activity in some region of the domain. LDC is combined with a fourth order compact scheme which is recently developed in Abbas (Num. Meth. Partial differential equations, 2013). Numerical tests illustrate the interest of this application.

Bayesian Analysis for Nonhomogeneous Poisson Process Software Reliability (비동질적 포아송과정을 사용한 소프트웨어 베이지안 신뢰성 분석에 관한 연구)

  • 김희철;이동철
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.22 no.49
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    • pp.23-31
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    • 1999
  • Bayesian approach using nonhomogeneous Poisson process is considered for modelling software reliability problem. The usefulness of the iterative sampling-based method increases greatly as the dimension of a problem increases. Maximum likelihood estimator and Gibbs estimator are derived. Model selection based on a predictive likelihood is studied. A numerical example is given.

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BOUNDARY COLLOCATION FAST POISSON SOLVER ON IRREGULAR DOMAINS

  • Lee, Dae-Shik
    • Journal of applied mathematics & informatics
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    • v.8 no.1
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    • pp.27-44
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    • 2001
  • A fast Poisson solver on irregular domains, based on bound-ary methods, is presented. The harmonic polynomial approximation of the solution of the associated homogeneous problem provides a good practical boundary method which allows a trivial parallel processing for solution evaluation or straightfoward computations of the interface values for domain decomposition/embedding. AMS Mathematics Subject Classification : 65N35, 65N55, 65Y05.

Semiparametric Bayesian multiple comparisons for Poisson Populations

  • Cho, Jang Sik;Kim, Dal Ho;Kang, Sang Gil
    • Communications for Statistical Applications and Methods
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    • v.8 no.2
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    • pp.427-434
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    • 2001
  • In this paper, we consider the nonparametric Bayesian approach to the multiple comparisons problem for I Poisson populations using Dirichlet process priors. We describe Gibbs sampling algorithm for calculating posterior probabilities for the hypotheses and calculate posterior probabilities for the hypotheses using Markov chain Monte Carlo. Also we provide a numerical example to illustrate the developed numerical technique.

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Discretization of Pressure-Poisson Equation for Solving Incompressible Navier-Stokes Equations Using Non-Staggered Grid (정규격자를 사용한 비압축성 Navier-Stokes 방정식의 수치해석을 위한 압력 Poisson 방정식의 이산화)

  • Kim Y. G.;Kim H. T.;Kim J. J.
    • 한국전산유체공학회:학술대회논문집
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    • 1998.11a
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    • pp.96-101
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    • 1998
  • Various discretiation methods of Laplacian operator in the Pressure-Poisson equation are investigated for the solution of incompressible Navier-Stokes equations using the non-staggered grid. Laplacian operators previously proposed by other researchers are applied to a Driven-Cavity problem. The computational results are compared with those of Ghia. The results show the characteristics of the discrete Laplacian operators.

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