• 한국환경과학회지
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• 제27권7호
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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.

• 한국해안해양공학회지
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• 제5권4호
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• pp.279-287
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• 1993

일정 수심 위를 전파하는 삼차원 파낭의 시간에 따른 변화를 Green함수를 사용하여 나타내었다. 본 논문에서 구한 해에 적절한 가정을 부여하면 기존의 해가 유도되므로 본 해는 보다 일반적인 해임을 입증하였다. 유도한 해를 수치적분하여 파낭 분산효과에 의한 파고 감소를 나타내고 이를 분석하였다.

• 한국실내디자인학회논문집
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• 제25호
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• pp.26-33
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• 2000

The end of the 20th century, on the ecological world-view which looks the whole things as systematic and admits the incessant change, human is considered to function with the environment mutually and to evolve in harmony with it. Because of the living style of the modern people whose most time spent inside of the buildings, eco-office elements are introduced in the inteior places where many general publics are gathered. We gather up the all information about Eco-office, introduction of green building certification system, Eco-office System Technics and provide source to how to design interact with eco-office.

• Coupled systems mechanics
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• 제9권1호
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• pp.77-89
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• 2020

This study is dedicated to the dynamic elasticity problem for a semi-strip. The semi-strip is loaded by the dynamic load at the center of its short edge. The conditions of fixing are given on the lateral sides of the semi-strip. The initial problem is reduced to one-dimensional problem with the help of Laplace's and Fourier's integral transforms. The one-dimensional boundary problem is formulated as the vector boundary problem in the transform's domain. Its solution is constructed as the superposition of the general solution for the homogeneous vector equation and the partial solution for the inhomogeneous vector equation. The matrix differential calculation is used for the deriving of the general solution. The partial solution is constructed with the help of Green's matrix-function, which is searched as the bilinear expansion. The case of steady-state oscillations is considered. The problem is reduced to the solving of the singular integral equation. The orthogonalization method is applied for the calculations. The stress state of the semi-strip is investigated for the different values of the frequency.

• The Journal of the Acoustical Society of Korea
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• 제22권4E호
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• pp.183-196
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• 2003

General algorithm is developed for the prediction of internal flow-induced noise. This algorithm is based on the integral formula derived by using the General Green Function, Lighthill's acoustic analogy and Curl'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 are compared with actual measurements. This illustrative computation shows that the current method penn its generalized predictions of flow noise generated by bluff bodies and turbulence in flow ducts.

• Journal of Photoscience
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• 제1권1호
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• pp.75-82
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• 1994

General features of the fluorescence depolarization are briefly reviewed. Molecular rotations and electronic excitation transports are considered to account for the fluorescence depolarization. Various molecular systems studied by the fluorescence depolarization are described. The FiSrster theory which forms a basis for the energy transfer is revisited. Several theoretical treatments for the fluorescence depolarization in liquid and solid phases such as classical hydrodynamics, probability distribution function, Green's function formalism, molecular dynamics simulation and Monte Carlo methods are introduced.

• 한국조경학회지
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• 제29권6호
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• pp.37-49
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• 2002

The objective of this research was an investigation of the important green spaces in Daegu and to present the basic frame of green network in Daegu. Present the condition of the significant green spaces is as follows: In the 3km radius of the city center, the isolation and discontinuation of the green spaces was extensive, caused by crowding of houses and funeral parlours. Consequently, the isolation relaxation which leads to the additional creation of the green spaces and a buffering plan were demanded. In the transfer area of a 3∼6km radius, which is located between the city center's congested area and the suburb green spaces, the significant green spaces had high connection and buffering characteristic, but in the northwest and the south, serious discontinuation appeared between the suburb green spaces and the city conte green spaces. In the 6∼9km radius, the suburb important green spaces accomplished the function which extended the back core green spaces to the city center area. But creation of buffering green spaces was necessary in part because of proximity to the resident area. The results suggest a connection between green spaces on the base of the distribution of the important green spaces, were as follows: In the 3km radius, irregular direction lines appeared while a schedule one direction line appeared in 3∼6km and 6∼9km radius. The discontinued parts of the green network were caused by industrial complexes, house crowding, and cultivation areas. Consequently, reservation and creation plans of green spaces in response to this were demanded. Through the additional creation of green spaces in the discontinued parts, the basic frame of green network in Daegu was the radiation annular form. And it was suitable to activate the parks and the general green spaces.

• 대한수학회보
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• 제54권2호
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• pp.507-519
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• 2017

We present an upper bound on the Cheeger constant of a distance-regular graph. Recently, the authors found an upper bound on the Cheeger constant of distance-regular graph under a certain restriction in their previous work. Our new bound in the current paper is much better than the previous bound, and it is a general bound with no restriction. We point out that our bound is explicitly computable by using the valencies and the intersection matrix of a distance-regular graph. As a major tool, we use the discrete Green's function, which is defined as the inverse of ${\beta}$-Laplacian for some positive real number ${\beta}$. We present some examples of distance-regular graphs, where we compute our upper bound on their Cheeger constants.

• 대한기계학회논문집A
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• 제31권9호
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• pp.967-974
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• 2007

A general form solution is considered for a piezoelectric material containing impermeable cracks subjected to a combined mechanical and in-plane electrical loading. The analysis is based upon the Hilbert problem formulation. Using this solution, typically for a central crack in transverse isotropic piezoelectric material, a closed form solution is obtained, where one concentrated mechanical and electrical load is subjected to the crack surface. This problem could be used as a Green's function to generate the solutions of other problems with the same geometry but of different loading conditions.

• 한국해양공학회지
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• 제15권4호
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• pp.1-7
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• 2001

Mainly, Floating Breakwaters (FBs) have been constructed in many coastal regions due to the advantages of the coastal environment and construction cost. In general, the FB becomes fixed or its width broadened because the movement of the FB comes to be large and its the wave control function lower for the long period incident waves. This study discusses the wave control function of two-rowed Fixed Floating Breakwater (FFBs) that have narrower width than that of the one-rowed FFB by using numerical approach. Boundary Element Method (BEM) based on the Green formula and Eigenfunction Expansion Method (EEM) are applied to evaluate the three-dimensional wave transformation near the wave fields of two-rowed FFBs. The validity of the present study is confirmed by comparing it with the results of Ijima et al. (1974) and Yoshida et al. (1992) for the one-rowed Fixed Floating Structure. It is revealed that the wave control function of two-rowed FFBs is more effective than that of the one-rowed FFB.