• Title/Summary/Keyword: green integral equation

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Improvement of the Convergence for the Green's Function in Three Layered Media (3층매질 Green함수의 수렴성 개선)

  • Hwang, Jae-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.219-222
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    • 2007
  • The paper deals with the rigorous analysis of three layered media structures. The dyadic Green's function for three layer medium is derived. The Green's functions belonging to the kernel of the integral equation are expressed as Sommerfeld integrals, in which surface wave effects are automatically included. We propose this integral representation as the most appropriate in the spatial domain analysis of slive structure. Also, we used extraction method for the convergence of this integral function. Finally, some numerical results are presented. These computed value show good agreement with proposed this method.

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EXISTENCE AND UNIQUENESS OF SOLUTIONS FOR A SINGULAR SYSTEM OF NONLINEAR FRACTIONAL DIFFERENTIAL EQUATIONS WITH INTEGRAL BOUNDARY CONDITIONS

  • Wang, Lin;Lu, Xinyi
    • Journal of applied mathematics & informatics
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    • v.31 no.5_6
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    • pp.877-894
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    • 2013
  • In this paper, we study the existence and uniqueness of solutions for a singular system of nonlinear fractional differential equations with integral boundary conditions. We obtain existence and uniqueness results of solutions by using the properties of the Green's function, a nonlinear alternative of Leray-Schauder type, Guo-Krasnoselskii's fixed point theorem in a cone. Some examples are included to show the applicability of our results.

Integral equation formulation for electromagnetic coupling through an arbitrarily shaped aperture into a parallel-plate waveguide (임의 형태의 개구에 의한 평행평판 도파관으로의 전자기적 결합 문제 해석을 위한 적분 방정식 방법)

  • Lee, Young-Soon;Lee, Chang-Won;Cho, Young-Ki;Son, Hyon
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.12
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    • pp.25-35
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    • 1995
  • An analysis method of electromagnetic coupling through an arbitrarily shaped aperture on the upper wall of parallel-plate waveguide, when excited by an electromagnetic plane wave from outside, is considered. The mixed-potential integral equation, in which Green's functions are expressed in a computationally efficient closed form by using the Prony's method and the Sommerfeld identity, is formulated. Expanding the unknown equivalent magnetic surface current in terms of two-dimensional rooftop-type basis functions and choosing razor testing, the integral equation is reduced to a linear algebraic equation, which is solved. The results are compared with the previous results. Fairly good agreements between them are observed.

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Numerical Modeling of Elastic Wave Scattering in an Isotropic Medium Containing an Orthotropic Inclusion (직교이방성 함유체를 포함하는 등방성 기지에서의 탄성파 산란 수치해석 모델)

  • Lee, Jung-Ki
    • Journal of the Korean Society for Nondestructive Testing
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    • v.21 no.1
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    • pp.69-79
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    • 2001
  • A volume integral equation method(VIEM) is applied for the effective analysis of elastic wave scattering problems in unbounded solids containing general anisotropic inclusions. It should be noted that this newly developed numerical method does not require the Green's function for anisotropic inclusions to solve this class of problems since only the Green's function for the unbounded isotropic matrix is Involved In their formulation for the analysis. nis new method can also be applied to general two-dimensional elastodynamic problems with arbitrary shapes and number of anisotropic inclusions. Through the analysis of plane elastodynamic problems in unbounded isotropic matrix with an orthotropic inclusion, it is established that this new method is very accurate and effective for solving plane elastic problems in unbounded solids containing general anisotropic inclusions.

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Three Dimensional Calculation of Capacitance for VLSI Interconnection Line (VLSI 전송선로에서의 커패시턴스의 3차원 계산)

  • 김한구;곽계달
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.7
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    • pp.64-72
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    • 1992
  • The capacitance for three-dimensional (3D) VLSI interconnection line is calculated. Capacitance is obtained by solving integral equation that is the product of Green's function and surface charge density. Surface charge density is assumed that constant in each subarea, and subarea is devided by rectangular size in interconnetion surfaces. Up to date, so this integral method using Green's function is calculated by Fourier integral transformation, that it cannot help making an error. In this paper, it is proposed to use direct integration instead of Fourier integral method. And we proved accuracy of this paper in comparision with conventional results.

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Analysis of orthotropic plates by the two-dimensional generalized FIT method

  • Zhang, Jinghui;Ullah, Salamat;Gao, Yuanyuan;Avcar, Mehmet;Civalek, Omer
    • Computers and Concrete
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    • v.26 no.5
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    • pp.421-427
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    • 2020
  • In this study, the two-dimensional generalized finite integral transform(FIT) approach was extended for new accurate thermal buckling analysis of fully clamped orthotropic thin plates. Clamped-clamped beam functions, which can automatically satisfy boundary conditions of the plate and orthogonality as an integral kernel to construct generalized integral transform pairs, are adopted. Through performing the transformation, the governing thermal buckling equation can be directly changed into solving linear algebraic equations, which reduces the complexity of the encountered mathematical problems and provides a more efficient solution. The obtained analytical thermal buckling solutions, including critical temperatures and mode shapes, match well with the finite element method (FEM) results, which verifies the precision and validity of the employed approach.

Elastic Analysis of a Half-Plane Containing Multiple Inclusions Using Volume Integral Equation Method (체적 적분방정식법을 이용한, 다수의 함유체를 포함한 반무한 고체에서의 탄성해석)

  • Lee, Jung-Ki;Ku, Duck-Young
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.2
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    • pp.148-161
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    • 2008
  • A volume integral equation method (VIEM) is used to calculate the plane elastostatic field in an isotropic elastic half-plane containing multiple isotropic or anisotropic inclusions subject to remote loading. A detailed analysis of stress field at the interface between the matrix and the central inclusion in the first column of square packing is carried out for different values of the distance between the center of the central inclusion in the first column of square packing of inclusions and the traction-free surface boundary in an isotropic elastic half-plane containing multiple isotropic or anisotropic inclusions. The method is shown to be very accurate and effective for investigating the local stresses in an isotropic elastic half-plane containing multiple isotropic or anisotropic inclusions.

Numerical Methods for Wave Response in Harbor (항만내의 파도 응답에 관한 수치 계산)

  • D.J.,Kim;K.J.,Bai
    • Bulletin of the Society of Naval Architects of Korea
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    • v.25 no.3
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    • pp.3-12
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    • 1988
  • A natural or an artificial harbor can exhibit frequency(or period) dependent water surface oscillations when excited by incident waves. Such oscillations in harbors can cause significant damage to moored ships and adjacent structures. This can also induce undesirable current in harbors. Many previous investigators have studied various aspects of harbor resonance problem. In the percent paper, both a localizes finite element method(LFEM) which is based on the functional constructed by Chen & Mei(1974) and Bai & Yeung(1974) and an integral equation method which was used by Lee(1969) are applied to harbor resonance problem. The present method(LFEM) shows computationally more efficient than the integral equation method. Our test results shows good agreement compared with other results. This enhanced computational efficiency is due to the fact that the present method gives a banded symmetric coefficients matrix and requires much less computational time in the calculation of the influence coefficients matrix than the integral equation method involved with Green's function. To test the present numerical scheme, two models are treated here. The present method(LFEM) can be extended to a fully three dimensional harbor problem with the similar computational advantage.

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Study of Nearshore OWC Wave Power Absorbing Breakwater (연안고정식 파력발전 겸 OWC 방파제 성능연구)

  • Hong, Do-Chun;Shin, Seung-Ho;Hong, Key-Yong;Hong, Seok-Won
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.465-468
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    • 2006
  • The wave power absorbing performance of a bottom-mounted oscillating water column (OWC) chamber structure is studied. The potential problem inside the chamber is solved by making use of the Green integral equation associated with the Rankine Green function while the outer problem with the Kelvin Green function taking account of fluctuating air pressure in the air chamber. The absorbed wave power, wave elevation inside the chamber, reflection coefficient and wave loads are calculated for various values of a parameter related to the fluctuating air pressure. The present methods can also be used for the design of a OWC breakwater which can absorb and reflect the incoming wave energy at the same time.

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On the Wave Loads on a Large Volume Offshore Structure (대형해양구조물에 작용하는 파랑하중에 관하여)

  • 홍도천;홍은영;이상무
    • Journal of Ocean Engineering and Technology
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    • v.1 no.1
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    • pp.33-38
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    • 1987
  • The first order mation responses of a floating structure and the hydrodynamic forces in regular waves are obtained by means of the linear potential theory. The first order potential is obtained directly from the numerical solution of the improved Green integral equation which is characterized by the combined surface distribution of sources and normal doublets. The mean second order wave drift force is also calculated by means of the near field method. It seems that the present method gives more accurate numerical results than other methods and the agreement between numerical and experimental results appears to be satisfactory.

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