• 제목/요약/키워드: parabolic equation

검색결과 250건 처리시간 0.022초

수정 완경사 파랑식에 대한 포물형 근사식 모형 (A Parabolic Model to the Modified Mild Slope Equation)

  • 서승남;이종찬
    • 한국해안해양공학회지
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    • 제18권4호
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    • pp.360-371
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    • 2006
  • 천해역의 파랑을 추산하기 위한 포물형 근사식에 대해 기존 모형을 도출할 수 있는 일반화된 모형을 제시하고 이를 수정 완경사 파랑식에 대한 포물형 근사식으로 확장하였다. 제시한 수치모형을 Berkhoff et al.(1982)의 수리모형 실험과 비교하였으며 이 경우에는 기존 포물형 근사모형과 수정 포물형 근사모형의 결과가 거의 같으며 수리실험 결과와 아주 잘 일치하는 것으로 나타났다. 따라서 계산이 빠르고 안정성이 높은 기존 포물형 근사식은 천해역의 파랑 추산에 유용한 도구라 판단된다.

Parabolic 방정식의 효율적인 시간해석 알고리즘에 대한 비교연구 (A Comparative Study of Efficient Transient Analysis Algorithm for Parabolic Equations)

  • 최창근;이은진;유원진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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    • pp.68-74
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    • 1998
  • A finite element analysis for physical phenomenon which are governed by parabolic equation, has some inefficiencies caused by much computational time and large storage space. In this paper, a comparative study is performed to suggest the best efficient transient analysis algorithms for parabolic equations. First, the general finite element analysis techniques are summarized in views of formulation procedures, treatments of convection terms. and time stepping methods. Results of several combinations applied to one dimensional convection-diffusion equation and Burger equation are represented and compared using some criteria such as accuracy, stability, and computational time. Through the results, some guidelines to select a algorithm for solving parabolic equations are proposed for diffusion dominant and convection dominant cases. Finally applicability of two dimensional extension of the result is also discussed.

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해저구릉 위로의 음의 전파를 설명하기 위한 Polar PE의 적용 (Application of the Polar Parabolic Equation Method for Sound Propagation over a Smooth Sea Mountain in the Ocean)

  • 유철수;윤석왕
    • The Journal of the Acoustical Society of Korea
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    • 제14권2E호
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    • pp.37-42
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    • 1995
  • 경계조건에 맞는 일련의 연속된 좌표계를 parabolic equation method에 적용한 polar parabolic equation method (Polar PE)는 하나의 곡면이나 언덕이 존재하는 경우 대기에서 음의 전파를 설명하는데 알맞은 수치 이론임이 입증되었다. 본 논문에서는 locally reacting 해저면과 pressure release 해수면의 경계조건을 사용하여 Polar PE 를 수중에서 해저구릉이 존재할 경우에 음의 전파를 설명하는데 적용하였다. 450m 높이의 해저구릉이 존재할 경우, 음의 전파에 관하여 계산하고 그 결과를 살펴보았다. Polar PE 를 수중에 해저구릉이 있는 경우 음의 전파를 계산하는데 적용가능성을 논의하였다.

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NEGATIVELY BOUNDED SOLUTIONS FOR A PARABOLIC PARTIAL DIFFERENTIAL EQUATION

  • FANG ZHONG BO;KWAK, MIN-KYU
    • 대한수학회보
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    • 제42권4호
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    • pp.829-836
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    • 2005
  • In this note, we introduce a new proof of the unique-ness and existence of a negatively bounded solution for a parabolic partial differential equation. The uniqueness in particular implies the finiteness of the Fourier spanning dimension of the global attractor and the existence allows a construction of an inertial manifold.

REGULARITY OF A DEGENERATE PARABOLIC EQUATION APPEARING IN VECER'S UNIFIED PRICING OF ASIAN OPTIONS

  • Dong, Hongjie;Kim, Seick
    • 대한수학회보
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    • 제52권3호
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    • pp.947-953
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    • 2015
  • Vecer derived a degenerate parabolic equation characterizing the price of Asian options with generally sampled average. It is well understood that there exists a unique probabilistic solution to Vecer's PDE but it remained unclear whether the probabilistic solution is a classical solution. We prove that the probabilistic solution to Vecer's PDE is indeed regular.

HARNACK INEQUALITY FOR A NONLINEAR PARABOLIC EQUATION UNDER GEOMETRIC FLOW

  • Zhao, Liang
    • 대한수학회보
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    • 제50권5호
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    • pp.1587-1598
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    • 2013
  • In this paper, we obtain some gradient estimates for positive solutions to the following nonlinear parabolic equation $$\frac{{\partial}u}{{\partial}t}={\triangle}u-b(x,t)u^{\sigma}$$ under general geometric flow on complete noncompact manifolds, where 0 < ${\sigma}$ < 1 is a real constant and $b(x,t)$ is a function which is $C^2$ in the $x$-variable and $C^1$ in the$t$-variable. As an application, we get an interesting Harnack inequality.

TWO NEW BLOW-UP CONDITIONS FOR A PSEUDO-PARABOLIC EQUATION WITH LOGARITHMIC NONLINEARITY

  • Ding, Hang;Zhou, Jun
    • 대한수학회보
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    • 제56권5호
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    • pp.1285-1296
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    • 2019
  • This paper deals with the blow-up phenomenon of solutions to a pseudo-parabolic equation with logarithmic nonlinearity, which was studied extensively in recent years. The previous result depends on the mountain-pass level d (see (1.6) for its definition). In this paper, we obtain two blow-up conditions which do not depend on d. Moreover, the upper bound of the blow-up time is obtained.

EXISTENCE AND LARGE TIME BEHAVIOR OF SOLUTIONS TO A FOURTH-ORDER DEGENERATE PARABOLIC EQUATION

  • LIANG, BO;WANG, MEISHAN;WANG, YING
    • 대한수학회보
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    • 제52권4호
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    • pp.1059-1068
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    • 2015
  • The paper is devoted to studying a fourth-order degenerate parabolic equation, which arises in fluid, phase transformation and biology. Based on the existence and uniqueness of one semi-discrete problem, two types of approximate solutions are introduced. By establishing some necessary uniform estimates for those approximate solutions, the existence and uniqueness of the corresponding parabolic problem are obtained. Moreover, the long time asymptotic behavior is established by the entropy functional method.