• 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.

• Food Quality and Culture
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• v.2 no.2
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• pp.89-96
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• 2008

In order to determine whether green tea tannin ameliorates abnormal arginine metabolism as the result of excessive arginine, we have assessed the effects of the administration of green tea tannin mixture in rats treated 30 days with 2% arginine. In the arginine-treated group, the level of guanidino compounds such as arginine (Arg), guanidinoacetic acid (GAA), creatinine (Cr), methylguanidine (MG) and guanidinosuccinic acid (GSA), nitric oxide, urea, protein and glucose increased significantly in the serum, urine and kidney, whereas the oxygen species-scavenging enzymes of kidney were reduced as compared with the non-arginine-treated group. By way of contrast, the administration of green tea tannin reduced blood urea nitrogen and serum creatinine, and reduced the urinary excretion of guanidinoacetic acid, creatinine, and $NO_2^-+NO_3^-$. The increased levels of urinary urea, protein and glucose in the arginine-treated group were also lowered by the administration of green tea tannin. In these groups, the activities of superoxide dismutase and catalase in the kidney were increased, thereby suggesting the involvement of radicals in the normalizing of kidney function. These results show that the abnormal renal function induced by the adminstration of excessive arginine in rats may be restored by treatment with green tea tannin.

• Journal of Environmental Science International
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• v.27 no.7
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• pp.519-529
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• 2018

With rapid economic growth, the urban environment has created a problem of human physical and mental illness. In order to solve these problems, urban forests have emerged as a way to mitigate the environmental risks through improving the polluted environment of the city and improve the quality of life. As the urban forests have expanded, the school forests movement has also been taking an important place recently. The study focused on the performance of school forests by comparing the perceptions among teachers and students about their functions. The questionnaire was composed of 4 questions concerning human matters, 10 questions for space recognition, 4 questions for thermal environment, 2 questions for health promotion, and 20 total questions for composition of survey items. The reliability of the school forest function, number of tree planting areas and quantities, the harmony of the planting, and the satisfaction of the school forest were analyzed in the questionnaire conducted by the school members. Although it does not recognize school forests, it has a positive response to the green space that is built outdoors. It is considered that outdoor education and environmental education are sufficient in school forests and green spaces. The results showed that the outdoor green space was more satisfactory when compared with the general school. Teachers and students' preferences were similar to 'seasonal changes' and' trees of various colors and shapes'. The reliability analysis between each item shows that the coefficient for cronbach's ${\alpha}$ was .700 to .834. The purpose of this study is to identify the perception of forest function among school forest members and to utilize them as a basic data in the future.

• Journal of Satellite, Information and Communications
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• v.4 no.2
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• pp.52-56
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• 2009

The design method of a four-port stripline circulator with a single ferrite disk is proposed using Green's function method. The four-port circulator gives the flexibility of the design of the communication system. Two cascaded three-port circulators has been used as a four-port circulator. However, if a four-port circulator with a single ferrite disk replace the present four-port circulator, then it will give less weight and volume and so has the advantage in satellite application.

• Journal of applied mathematics & informatics
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• v.27 no.1_2
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• pp.183-194
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• 2009

In this paper, we considered the following four-point boundary value problem $\{{x"(t)+h(t)f(t,x(t),x'(t))=0,\;0<t<1\atop%20x'(0)=ax(\xi),\;x'(1)=bx(\eta)}\$. where $0\;<\;{\xi}\;<\;{\eta}\;<\;1,\;{\delta}\;=\;ab{\xi}\;-\;ab{\eta}\;+\;a\;-\;b\;<\;0,\;0\;<\;a\;<\;\frac{1}{\xi},\;0\;<\;b\;<\;\frac{1}{\eta}$. After the discussion of the Green function of the corresponding homogeneous system, we establish some criteria for the existence of positive solutions by using the generalized Leggett-William's fixed point theorem. The interesting point is the expression of the Green function, which is a difficulty for multi-point BVP.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.403-405
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• 2003

An iterative Green's function method (IGFM) is introduced to analyze complex electromagnetic waveguide structures in view of the university student. The IGFM utilizes the Green's function and iteration scheme. The physical mechanism with simple mathematical equations is used to formulate the IGFM. Scattering characteristics of a standard E-plane T-junction in a parallel-plate waveguide are theoretically investigated in terms of the IGFM. Numerical computations illustrate the characteristics of resection and transmission powers versus frequency. A dominant-mode solution is presented and compared with the higher-mode solutions.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1530-1537
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• 1991

본 연구에서는 반무한 직선 계면균열의 상하면에 임의로 분포하는 어떠한 하 중에 대해서도 그 해석이 가능한 그린함수(Green's function)를 구하고자 한다. 이 를 위하여 반무한 직선 계면균열상의 임의의 한 점에 평면 집중하중이 작용하는 문제 와 비평면 집중전단하중이 작용하는 문제를 각각 택하였고, 이때 계면균열의 선단은 열려있다고 가정하였다. 이 문제를 풀므로써 균열선단부근의 응력성분을 결정하고 이로부터 그린함수의 의미를 지니는 응력강도계수에 대한 폐형해를 얻었다.

• Journal of the Korean Mathematical Society
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• v.50 no.3
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• pp.509-527
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• 2013

A Krawtchouk polynomial is introduced as the classical Mac-Williams identity, which can be expressed in weight-enumerator-free form of a linear code and its dual code over a Hamming scheme. In this paper we find a new explicit expression for the $p$-number and the $q$-number, which are more generalized notions of the Krawtchouk polynomial in the P-polynomial schemes by using an extended version of a discrete Green's function. As corollaries, we obtain a new expression of the Krawtchouk polynomial over the Hamming scheme and the Eberlein polynomial over the Johnson scheme. Furthermore, we find another version of the MacWilliams identity over a Hamming scheme.

• International Journal of Aeronautical and Space Sciences
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• v.2 no.2
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• pp.46-55
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• 2001

A Green's function approach based on the laminate theory is adopted to obtain the unsteady temperature distributions in a semi-infinite hollow circular cylinder made of functionally graded materials (FGMs). The transient heat conduction equation based on the laminate theory is formulated into an eigenvalue problem for each layer by using the eigenfunction expansion theory and the separation of variables. The eigenvalues and the corresponding eigenfunctions obtained by solving an eigenvalue problem for each layer constitute the Green's function solution for analyzing the unsteady temperature distributions. Numerical calculations are carried out for the semi-infinite hollow circular FGM cylinder subjected to partially heated loads, and the numerical results are shown in figures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.10
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• pp.2703-2709
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• 1996

This paper proposes an exact numerical method for analyzing a dipole antenna attached on a dielectric slab. A Green's function for an infinitesimal current filament on a dielectric slab is derived and a field integral equation is formulated using a boundary condition. The moment Method is used to solve the field integral equation to otain current distribution on the antenna. Since an asymptotic function is used to compute the impedance matrix elements, the computataion time is significantly reduced. Using the computed current distributions, the input impedances, the resonance lengths and the resonant resistances of the antennas for various values of the thichnessandthe dielectric constant of the slab are obtained. It was found that the resonant length and the resonant resistance are decrease monotonically as the dielectric constant increases, however, those are changed up-and-down as the substrate thickness increases.