• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2000년도 춘계학술대회 논문집
• /
• pp.23-28
• /
• 2000

The Green integral equation for the calculation of the forward-speed time-harmonic radiation-diffraction potentials IS derived. The forward-speed Green function presented by Brard is used and the correct free surface boundary condition for the Green function is imposed. The cause of the mistakes in the existing Green integral equation is also pointed out.

• 한국해양공학회지
• /
• 제11권2호
• /
• pp.91-99
• /
• 1997

This paper presents theoretical formulations and numerical computations for predicting first-and second-order hydrodynamic force on a ship advvancing in waves. The theoretical formulation leads to linearized radiation and diffration problems solving the three-dimensional Green function integral equations over the mean wetted body surface. Green function representing a translating and pulsating source potantial for infinite water depth is used. In order to solve integral equations for three dimentional flows using Green function efficiently, the Hoff's method is adopted for numerical calculation of the Green function. Based on the first-order solution, the mean seconder-order forces and moments are obtained by directly integrating second-order pressure over the mean wetted body surface. The calculated items are carried out for analyzing the seakeeping characteristics of Series 60. The calculated items are hydrodynamic coefficients, wave exciting forces, frequency response functions and addd resistance in waves.

• 충청수학회지
• /
• 제11권1호
• /
• pp.163-172
• /
• 1998

In this paper, we will study properties of the Green's potential for the Green's function of B which is defined in [8]. In particular, we will investigate boundary behavior of some functions related with Green's function within tangential approach regions that were used in [4].

• 한국정보통신학회논문지
• /
• 제5권5호
• /
• pp.1001-1010
• /
• 2001

TLM 법에서 이산 그린함수 흡수경계는 광대역에서 정밀한 수치해석에 사용되어왔다. 그러나 이산 그린함수 흡수경계는 이산 그린함수를 얻는 수치해석이 부가적으로 요구되기 때문에 흡수경계를 적용하는 과정이 복잡하다. 그러므로 흡수경계를 적용하는 과정의 간소화를 위해서 본 논문에서는 새로운 그린 흡수층을 제안한다. 제안된 그린 흡수층은 이산 그린함수의 손실처리 방법을 응용하여 구현하였으며 최적의 흡수 상태를 그린 흡수층의 길이에 대응하는 손실 증가율과 감쇠상수리 관계로 얻을 수 있었다. 또한 최적의 흡수상태가 되는 그린 흡수층을 적용하여 도파관 대역통과필터를 해석하였다. 그 결과, 기존의 그린함수 흡수경계와 제안된 그린 흡수층을 적용한 해석 결과가 정확히 일치하였다.

• 한국생산제조학회지
• /
• 제24권5호
• /
• pp.535-540
• /
• 2015

We propose an enhanced Green's function approach to predict thermal stresses by considering temperature-dependent material properties. We introduce three correction factors for the maximum stress, the time taken to reach maximum stress, and the time required to attain steady state based on the Green's function results for each temperature. The proposed approach considers temperature-dependent material properties using correction factors, which are defined as polynomial expressions with respect to temperatures based on Green's functions, that we obtain from finite-element (FE) analyses at each temperature. We verify the proposed approach by performing detailed FE analyses on thermal transients. The Green's functions predicted by the proposed approach are in good agreement with those obtained from FE analyses for all temperatures. Moreover, the thermal stresses predicted using the proposed approach are also in good agreement with the FE results, and the proposed approach provides better predictions than the conventional Green's function approach using constant, time-independent material properties.

• Earthquakes and Structures
• /
• 제3권3_4호
• /
• pp.507-518
• /
• 2012

It is now widely accepted that the resulting displacement field within elastic, inhomogeneous, anisotropic solids subjected to equipartitioned, uniform illumination from uncorrelated sources, has intensities that follow diffusion-like equations. Typically, coda waves are invoked to illustrate this concept. These waves arrive later as a consequence of multiple scattering and appear at "the tail" (coda, in Latin) of seismograms and are usually considered an example of diffuse field. It has been demonstrated that the average correlations of motions within a diffuse field, in frequency domain, is proportional to the imaginary part of Green's function tensor. If only one station is available, the average autocorrelation is equal to the average squared amplitudes or the average power spectrum and this gives the Green's function at the source itself. Several works address this point from theoretical and experimental point of view. However, a complete and explicit analytical description is lacking. In this work we study analytically some properties of the Green's function, specifically the imaginary part of Green's function for 2D antiplane problems. This choice is guided by the fact that these scalar problems have a closed analytical solution (Kausel 2006). We assume the diffusiveness of the field and explore its analytical consequences.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2009년도 제37회 하계학술대회 초록집
• /
• pp.142-142
• /
• 2009

• Journal of electromagnetic engineering and science
• /
• 제1권1호
• /
• pp.54-59
• /
• 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.

• 한국조경학회지
• /
• 제35권2호통권121호
• /
• pp.81-90
• /
• 2007

This study used the functions for public benefits as a standard for evaluating Green Tourism. By referring to the existing literature, the "function of building emotion", the "function of providing a natural environment", the "function of preserving traditional cultures", and the "function of maintaining the local community" have been selected as the measuring variables. Detailed sub-variables of each function were prepared to examine and analyze the recognition of these are the part of Green Tourists. The Green Tourists of Yangsuri in Yangpyeong, Sinnonri in Yangpyeong, and Jurokri in Yeoju participated in the survey for which 13 variables were used as measurement. The results are as follows: First, Green Tourists recognize farm villages as places for rest and relaxation and they laid great importance on the function of providing access to the natural environment. Secondly, out of the 13 measurement variables, "beautiful scenery in farm village", "making a contribution to village income", and "trust in agricultural products" greatly influenced the overall evaluation of Green Tourism. Thirdly, regarding the relationship between the functions for public benefits and Green Tourism, it was found that "facilities and activities for experiencing farming", "facilities for rest", and "beautiful scenery in farm villages" are closely related to building the emotion experienced in these villages, and that "cultivating environmentally-friendly agricultural products" and "beautiful scenery in farm village" are closely related to the function of providing access to the natural environment.

• Journal of the Korean Institute of Landscape Architecture International Edition
• /
• 제2호
• /
• pp.88-93
• /
• 2004

This research aims to grasp the basic knowledge of green belt, which exerts far-reaching effects upon safety, by comparing the revelation of the green belt of the two cities-Japan and China. In result, features of both countries were clarified. The green belt of Japan emphasizes on the function during emergency cases such as natural disasters, while the green belt in China, stresses its' function toward social safety in usual status, such as crimes, accidents or environmental pollution. Also, the function of the green space at normal situations has many in common between these two countries; however, the concepts differ according to geological or social system.