• 대한전자공학회논문지TC
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• 제41권6호
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• pp.79-86
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• 2004

정확한 closed-form 근린함수 계산방법은 공간영역 그린함수에 포함된 Sommerfeld 적분의 계산시간을 줄이기 위해 기존에 이용되어온 복소 영상법(Complex image method)과 2단계 근사화법(Two-level approach)에 비해 훨씬 적은 오차를 갖는다. 본 논문에서는 정확한 closed-form 그린함수 계산방법을 일반적인 전원을 포함하는 평판구조에 적용하는 방법을 제안하였다.

• Journal of electromagnetic engineering and science
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• 제1권1호
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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.

• 한국해양공학회지
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• 제24권1호
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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.

• Earthquakes and Structures
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• 제9권2호
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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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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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.

• Journal of the Korean Statistical Society
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• 제19권2호
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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.

• 한국조경학회지
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• 제32권2호
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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.

• 비파괴검사학회지
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• 제21권1호
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• pp.69-79
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• 2001

다수의 이방성 함유체를 포함하는 등방성 무한고체에서 이들 이방성 함유체에 의한 탄성파의 산란문제 해석을 효과적으로 수행할 수 있는 새로은 수치해석 방법으로 체적 적분방정식법을 제시하였다. 체적 적분방정식법에서는 등방성 무한고체에서의 Green 함수만 구할 수 있으면 이방성 함유체에서의 Green 함수를 구하지 않고서도 탄성파 산란문제 해석이 가능해지는 장점이 있다. 이 방법은 임의의 형상을 갖는 다수의 이방성 함유체가 포함된 일반적인 탄성동역학 문제 해석에도 적용이 가능하다. 한 개의 직교이방성 함유체가 등방성 무한기지에 포함된 무한고체에서 직교이방성 함유체에 의한 종과(P파) 및 횡파(SV파) 산란문제 해석을 통하여, 체적 적분방정식법이 일반적인 이방성 함유체가 포함된 무한고체에서의 탄성파 산란문제 해석에 있어 정확하고 효과적인 수치해석 방법임을 입증하였다.

• 한국소음진동공학회논문집
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• 제14권4호
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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.

• 대한기계학회논문집A
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• 제23권11호
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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.