• Title/Summary/Keyword: General Green Function

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An Accurate Closed-form Green's Function for the Planar Structure with General Sources (일반적인 전원을 포함하는 평판구조에 대한 정확한 Closed-form 그린함수)

  • Kang Yeon-Duk;Lee Taek-Kyung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.6 s.324
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    • pp.79-86
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    • 2004
  • In the integration of Sommerfeld type for space domain Green's function, a accurate closed-from Green's function method provides more exact solution than the typical complex image method and two-level method. The accurate closed-form Green's function method is applied to obtain the space domain Green's functions of planar structures with general sources. Please put the abstract of paper here.

Dyadic Green`s Function for an Unbounded Anisotropic Medium in Cylindrical Coordinates

  • Kai Li;Park, Seong-Ook;Pan, Wei-Yan
    • Journal of electromagnetic engineering and science
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    • v.1 no.1
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    • pp.54-59
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    • 2001
  • The dyadic Green`s function for an unbounded anisotropic medium is treated analytically in the Fourier domain. The Green`s function, which is expressed as a triple Fourier integral, can be next reduced to a double integral by performing the integral, by performing the integration over the longitudinal Fourier variable or the transverse Fourier variable. The singular behavior of Green`s is discussed for the general anisotropic case.

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An Asymptotic Solution and the Green's Function for the Transverse Vibration of Beams with Variable Properties

  • Kim, Yong-Chul
    • Journal of Ocean Engineering and Technology
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    • v.24 no.1
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    • pp.34-38
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    • 2010
  • An analytical solution procedure for the dynamic response of beams with variable properties is developed by using an asymptotic solution and the Green's function. This asymptotic closed form solution is derived for the transverse vibration of beams under the assumption of slowly varying properties, such as mass, cross-section, tension etc., along the beam length. However, this solution is still found to be very accurate even in the case of large variation, such as step change in cross-section, mass, and tension. Therefore, this derived asymptotic closed form solution and the Green's function can be easily applied to find dynamic responses for various kind of beam vibration problems.

SH-wave propagation in a heterogeneous layer over an inhomogeneous isotropic elastic half-space

  • Kakar, Rajneesh
    • Earthquakes and Structures
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    • v.9 no.2
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    • pp.305-320
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    • 2015
  • The present paper is devoted to study SH-wave propagation in heterogeneous layer laying over an inhomogeneous isotropic elastic half-space. The dispersion relation for propagation of said waves is derived with Green's function method and Fourier transform. As a special case when the upper layer and lower half-space are homogeneous, our derived equation is in agreement with the general equation of Love wave. Numerically, it is observed that the velocity of SH-wave increases with the increase of inhomogeneity parameter.

Elastic Analysis of Unbounded Solids Using a Mixed Numerical Method (혼합 수치해석 방법을 이용한 무한고체의 탄성해석)

  • Lee , Jung-Ki;Heo, Kang-Il
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.341-348
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    • 2001
  • A Mixed Volume and Boundary Integral Equation Method is applied for the effective analysis of plane elastostatic problems in unbounded solids containing general anisotropic inclusions and voids or isotropic 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 Green's function for the unbounded isotropic matrix is involved in their formulation for the analysis. This new method can also be applied to general two-dimensional elastodynamic and elastostatic problems with arbitrary shapes and number of anisotropic inclusions and voids or isotropic inclusions. Through the analysis of plane elastostatic problems in unbounded isotropic matrix with orthotropic inclusions and voids or isotropic inclusions, it will be established that this new method is very accurate and effective for solving plane elastic problems in unbounded solids containing general anisotropic inclusions and voids or isotropic inclusions.

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On The Derivation of a Certain Noncentral t Distribution

  • Gupta, A.K.;Kabe, D.G.
    • Journal of the Korean Statistical Society
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    • v.19 no.2
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    • pp.182-185
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    • 1990
  • Let a p-component vector y have a p-variate normal distribution $N(b\theta, \Sigma), \Sigma$ unknown, b specified, then for testing $\theta = 0$ against general $\theta$, Khatri and Rao (1987) derive a certain t test and obtain its power function. This paper presents a direct derivation of this power function in terms of the original variates unlike Khatri and Rao (1987) who resort to the canonical transformations of the original variates and the conditional distributions.

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Design and Planning Criteria for the Green Buffer Zone (환경친화적 완충녹지의 기준설정)

  • 박은영;유병림
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.2
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    • pp.25-35
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    • 2004
  • The purpose of the study is to analyze the existing situation of the green buffer zone in the large scale industrial site and other major residential apartment areas. In this study, it is specifically intended that the planning guideline be upgraded to adopt future landuse trends and thus to suggest design criteria for management of the buffer zone. The framework of the analysis is to review the current landuse, noise reduction, ecological implications and landscape in general. Although the major function of a green buffer zone is considered to protect the residential area from various hazards of industrial, traffic, and visual environment, the situation is that most of the zones are maintained at a minimum level of services by local government. The study carried out intensively almost every type of case studied throughout the country, which implies that the management of the green buffer zone should be expanded physically enough to function for its original objectives. The study recommends that ecological management of the green buffer zone be emphasized and therefore the criteria for this purpose as well as noise issue should be developed prior to the landuse aspects. The study suggests specific guidelines for planning and design for the green buffer zone development. This study should be verified positively through the sustainable monitoring and requires nationwide and overall examination so that it may be applied to whole green spaces.

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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Internal Aerodynamic Noise from Quick Opening Throttle Valve (쓰로틀 밸브의 빠른 열림 동작에 의한 내부공력소음)

  • 정철웅;김성태;김재헌;이수갑
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.4
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    • pp.310-318
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    • 2004
  • For many industrial problems originating from aerodynamic noise, noise prediction techniques, reliable and easy to apply, would be of great value to engineers and manufacturers. General algorithm is presented for the prediction of internal flow-induced noise from quick opening throttle valve in an automotive engine. This algorithm is based on the integral formula derived by using the General Green Function, Lighthill's acoustic analogy and Curle's extension of Lighthill's. Novel approach of this algorithm is that the integral formula is so arranged as to predict frequency-domain acoustic signal at any location in a duct by using unsteady flow data in space and time, which can be provided by the Computational Fluid Dynamics Techniques. This semi-analytic model is applied to the prediction of internal aerodynamic noise from a throttle valve in an automotive engine. The predicted noise levels from the throttle valve show good agreement with actual measurements. The results show that the dipole noise is dominant in this phenomena and the origin of noise sources is attributed to the anti-vortex lines formed in the down-stream from a throttle valve. This illustrative computation shows that the current method permits generalized predictions of flow noise generated by bluff bodies and turbulence in flow ducts.

Elastic Analysis of Unbounded Solids with Anisotropic Inclusions (이방성 함유체를 포함하는 무한고체의 탄성해석)

  • Choe, Seong-Jun;Ra, Won-Seok;Lee, Jeong-Gi
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.11 s.170
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    • pp.1993-2006
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    • 1999
  • A Volume Integral Equation Method (VIEM) is applied for the effective analysis of elastic wave scattering problems and plane elastostatic 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 Green's function for the unbounded isotropic matrix is involved in their formulation for the analysis. This new method can also be applied to general two-dimensional elastodynamic and elastostatic problems with arbitrary shapes and number of anisotropic inclusions and voids. Through the analysis of plane elastodynamic and elastostatic problems in unbounded isotropic matrix with orthotropic inclusions and voids, it will be established that this new method is very accurate and effective for solving plane elastic problems in unbounded solids containing general anisotropic inclusions and voids.