• 한국조경학회지
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• 제36권3호
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• pp.39-51
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• 2008

본 연구는 1980년대 도심 도로변 환경 영향 저감 기능 목적으로 조성된 완충녹지를 대상으로 다양한 도시녹지 기능 보완을 위한 완충녹지 재정비 방안 연구이다. 사례 대상지는 서울시 송파구내 송파대로와 남부순환로 도로변에 조성된 완충녹지이다. 완충녹지 주변 토지이용을 고려하여 완충녹지 기능을 재설정한 후 완충, 경관개선, 녹음기회 제공, 생태적 기능성 등을 강화할 수 있는 식재방안을 제안하였다. 송파구 녹지체계의 근간을 이루고 있는 송파대로, 남부순환로 주변 완충녹지 주변에는 고층아파트지역, 연립빌라지역, 근린상업지역, 상업업무지역, 교통시설지역, 도시부양시설지역, 학교 등 다양한 토지이용이 분포하였다. 그러나 완충녹지의 식재기능은 대부분 교목층에 양버즘나무, 은행나무, 느티나무 등이 교호식재되었고, 관목층에 개나리, 쥐똥나무 등을 열식하여 완충기능 일변도의 획일화된 패턴이었다. 현재 녹지의 다양한 기능을 발휘하지 못한 채 대부분 차량 영향 저감 기능 일변도의 획일적인 식재기능 및 식재양식으로 조성되어 있었다. 이에 보도를 중심으로 보행자의 보행환경과 경관개선 요구가 증대되고 완충녹지를 이용하고자 하는 요구를 고려하여 차량 영향 저감 기능뿐만 아니라 주변 토지이용에 따라 다양한 도시녹지로서의 기능을 충족할 수 있도록 완충녹지의 재정비 방안이 필요하였다. 송파구 도심 내 완충녹지 주변 토지이용과의 관계성과 완충녹지의 물리적 . 생태적 구조를 고려하여 완충기능뿐만 아니라 도시녹지로서 다양한 역할을 수행할 수 있도록 완충+경관기능, 경관+완충기능, 완충+녹음 기능 완충+생태기능으로 설정하였다. 그리고 다각적인 완충녹지 기능에 부합하는 식재기능, 식재종류, 식재양식, 시설물 등의 식재개선 방안을 제안하였다.

• 한국조경학회지
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• 제26권2호
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• pp.54-61
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• 1998

The subsurface environment of the root zone area can set the stae for "do or die" of the turfgrass plant. The good condition of the greens is verified by their physical properties. Therefore, this study was carried to evaluate on the existing green of Hwasan C.C. by undisturbed soil Core Anaysis. We completed the ISTRC SYSTEM BenchMarking of the undisturbed core samples taken from Green #1, Green #5, Green #9-"Best" area, and Green #9-"Stressed" area for the Hwasan C.C.. It was also our understanding that the greens were in "good" to "very good" conditioni. THe exception might be Green #9-"Stress" area, which was the stressed area. The stressed area was confined to a ridge across Green #9. The organic content test results comfirmed the development of organic layering in depth 0-2.5cm. For the amount of compaction in the upper root zones and te development of the green's respective organic layers, the infiltration rates were high in Green #1, Green #5, and Green #9 "Stressed" area. The depicted aerificaton hole might be the probable cause of the relatively high infiltraton rate. Green #9-"Best" area had a tested infiltration rate of 18.75cm/hr. Either this area had not been aerified, or the undisturbed sample did not contain a aerification cavity. The water retention capacity of the undisturbed samples was good. When the greens were first constructed, the original root zone mix had been relatively low water retention properties. And the bulk density and the porosity of the undisturbed samples were good. In the result, all the greens were similar except for the infiltration. Thus, we supposed that Green #9-"Stressed" area might be ainly influenced by the amount of irrigation water and the configuration of the green's surface. There had been a reduction in the amount of irrigation water as the water retention capacity in the greens was promoted. Especially, it had gradually become more of a problem as the green had matured in Green #9-"Stressed" area. Because Green #9-"Stressed" area was a ridge area. The reduction in the amount of irrigation water might be the probable cause of the stress in Green #9-"Stressed" area. Our final observation related to the soil texture and the particle size distribution of the sand. Though and sand contant of all the tested greens were good, the gravel content of them exceeded ISTRC Guidelines. In particle size distribution of the sand, the very coarse and the coarse content of all the tested greens exceeded, but the rest was insufficient. The stability is a function of the material retained on the 0.25mm mesh screen. But, the content of all the tested greens was very insufficient. Though all the greens was serviceable, the coarse root zone sands, such as the sand in the tested greens, tended to be "unstable". Thus, we recommend using a topdressing/aerification sand which should be more in line with ISTRC/USGA Guidelines.;unstable". Thus, we recommend using a topdressing/aerification sand which should be more in line with ISTRC/USGA Guidelines.ines.

• 전자공학회논문지A
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• 제30A권11호
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• pp.88-98
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• 1993

In this paper, the effective permittivity in the piezoelectric material is numerically obtained and greens function is derived from that. It is shown that the admittance and the transfer function of an interdigital transducer is represented by electrostatic charge distribution using Quasi-static approximation. To prove the validity of the quasi-static approximation, numerical results for the uniform IDT of a filter mounted on 128 $^{\circ}$ rotated Y-cut X-propagating Lithium Niobate are compared with the measured ones.

• 대한기계학회논문집A
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• 제21권9호
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• pp.1441-1451
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• 1997

This paper addresses method which can be used for analyzing thermal stresses of a functionally graded material(FGM) using semi-analytical approach. FGM is a nonhomogeneous material whose composition changes continuously from a metal surface to a ceramic surface. An infinite one dimensional FGM plate is considered. The temperature distribution in the FGM is obtained by approximate Green's function solution. To expedite the convergence of the solutions, alternative Green's function solution is derived and shows good agreement with results from finite difference method. Thermal stresses are calculated using temperature distribution of the plate.

• 대한기계학회논문집A
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• 제22권1호
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• pp.16-22
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• 1998

This paper addresses a method which can be used for analyzing thermal stresses of a functionally graded material(FGM) using semi-analytical approach. FGM is a nonhomogeneous material whose composition is changed continuously from a metal surface to a ceramic surface. An infinite one dimensional FGM plate is considered. The temperature distribution in the FGM is obtained by approximate Green's function solution. To expedite the convergence of the solutions, alternative Green's function solution is derived and shows good agreement with results from finite difference method. Thermal stresses are calculated using temperature distribution of the plate.

• 한국자동차공학회논문집
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• 제6권2호
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• pp.144-154
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• 1998

A functionally graded material is a nonhomogeneous material, which is composed of several different materials to maintain structural rigidity and endure high temperature loads. An analytical method is presenter to solve the unsteady heat conduction equation for nonhomogeneous materials. A one-dimensional infinite plate made of functionally graded material is considered. The approximate Green's function solution is derived and to be used to obtain the temperature distribution them the stress distributions may be obtained. The volume fraction, the porosity, the stress difference, and the stress ratio are the design parameters and are to be used to set up a systematic design procedure.

• 소음진동
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• 제8권5호
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• pp.807-813
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• 1998

Transmission loss of the simple expansion chamber with multiple inlet and outlet ports is obtained. Transfer matrices which represent the relation between the power variables(pressure and velocity) of inlets and outlets depend on the input relatons as well as the acoustic system parameters(i.e. geometry of the chamber, wall admittance, etc.). The analysis has been performed analytically, including the effects of higher order modes for the 2-inlet/1-outlet, 1-inlet/2-outlet and 2-inlet/2-outlet systems. This study yeilds that phase difference between the inlet ports can significantly increase the transmission loss in low frequency range.

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.499-505
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• 2017

Photoisomerizing molecules which can transform their structure by the light irradiation have great deal for the application of photo-switching devices. And azobenzene is the representive type of the photoisomerizing molecules. It can transform their trans- structures into cis- structure as the light for certain wave lengths they receive. This property shows the potential of ON/OFF switching functionalization which can be used into the nano scale photo switch. Furthermore, many studies are interested in the organic linkers that connect the azobenzene and metal electrodes. We used S, $CH_2S$, $(CH_2)_4S$ as the linker to watch the influence of linkers for electronic properties. So We suggest a photoswitching device based on the vertical junction using the first-principles calculations with density functional theory and non-equilibrium Greens function (NEGF). By analyzing the electronic structure and tunneling current caused by the structural difference of the system between cis- and trans- azobenzene, the difference in switching mechanism, ON/OFF ratio and transmission will be watched as the linker changes. And finally We will suggest which linker would be the better for the optimal device architecture which can achieve high control of the ON/OFF photocurrent ratio. This result will show the potential of azobenzene-based photoswitch and provide the critical insight in constructing the optimal device architecture.

• 한국식품영양과학회지
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• 제23권2호
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• pp.315-321
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• 1994

In order to prevent the postharvest decay and to promote the freshness retention of fruits and vegetables grapefruit seed extract(GFSE), natural microorganism control agent, was applied to the preservation of fresh fruits and vegetables. Freshfruits and vegetables treated with GFSE and stored in polyethylene film (0.1mm) at 1$0^{\circ}C$-15$^{\circ}C$ of natural low temperature low kept better qualities in color and texture than the GFSE -not- treated control. The treatment using GFSE ina 250ppm to 500ppm concentration seemed to be an effective one for the control of Botrytis cinerea isolated in red wine grapes. After 4 weeks of storage the firmness rate of cucumbers treated with the dilute GFSE was four times higher than that of non-treated ones. GFSE showed effective inhibitory action towards plant pathological bacteria and fungi which were involved in the decay of fruits and vegetables. Minimum inhibitory concentrations of GFSE towards them were in the range of 250ppm to 500ppm .Direct visualization of microbial cells and spores using electron microscopy showed microbial cells and fungal spores the function of which was destroyed by treating with the dilute solutions of GFSE. It was observed that GFSE would reduced disease damages and have bactericide & fungicide properties during the storage of such fruits and vegetables as egg plant, wild edible greens , kumquat, and kiwi fruit.

• 한국환경생태학회지
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• 제22권6호
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• pp.691-706
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• 2008

본 연구에서는 해안 매립도시인 안산시 철도변 완충녹지를 대상으로 완충녹지의 문제점을 분석하고, 완충녹지의 공간기능과 식재개념에 적합한 식재방안을 제시하였다. 안산시 철도별 완충녹지의 식재밀도는 $0.04{\sim}0.17$주/$m^2$ 이었고, 녹지용적계수는 $0.15{\sim}1.65m^3/m^2$로 녹량이 부족하여 완충기능이 미흡하였다. 마운딩 완충녹지의 토양경도는 $2.72{\sim}15kg/cm^2$로 식생생육에 적합하지 않았다. 완충녹지의 기능을 향상시키기 위해 야생조류 서식 측면의 생물서식기능, 주변 토지이용 측면의 도시공원기능, 식재수종 계절성 측면의 경관개선기능을 검토하였다. 완충녹지를 기능에 따라 생물서식기능의 완충녹지, 완충 및 경관개선기능의 완충녹지, 경관 및 도시공원기능의 완충녹지, 완충 및 생물서식기능의 완충녹지로 재설정하였다. 완충기능 식재방안에서는 곰솔 등을 주요종으로 선정하고, 교목종 0.4주/$m^2$, 관목종 0.5주/$m^2$로 식재밀도를 설정하였고, 경관개선 기능에서는 느티나무, 산벚나무, 살구나무 등을 주요종으로 선정하고 교목종 0.2주/$m^2$, 관목종 0.5주/$m^2$로 식재밀도를 설정하였다. 생물서식기능에서는 상수리나무, 산벚나무, 팥배나무 등을 주요종으로 선정하고, 적정 식재 밀도를 교목종 0.06주/$m^2$, 아교목종 0.1주/$m^2$, 관목종 0.8주/$m^2$로 식재밀도를 제시하였다.