• International Journal of Automotive Technology
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• 제6권6호
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• pp.591-598
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• 2005

A three-way catalyst system of a natural gas vehicle (NGV) has characteristics of higher fuel consumption and higher thermal load than a lean-bum catalyst system. To meet stringent emission standards in the future, NGV with the lean-bum engine may need a catalyst system to reduce the amounts of HC, CO and NOx emission, although natural gas system has low emission characteristics. We conducted experiments to evaluate the conversion efficiency of the NOx reduction catalyst for the lean-burn natural gas engine. The NOx reduction catalysts were prepared with the ${\gamma}-Al_{2}O_3$ washcoat including Ba based on Pt, Pd and Rh precious metal. In the experiments, effective parameters were space velocity, spike duration of the rich condition, and the temperature of flowing model gas. From the results of the experiments, we found that the temperature for maximum NOx reduction was around $450^{\circ}C$, and the space velocity for optimum NOx reduction was around $30,000\;h^{-1}$ And we developed an evaluation model of the NOx reduction catalyst to evaluate the conversion performance of each other catalysts.

• 한국컴퓨터산업학회논문지
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• 제2권12호
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• pp.1601-1608
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• 2001

디지털 도서관은 자연어 문서와 멀티미디어 자료에 대한 정보 검색 엔진을 필요로 하는 가장 중요한 데이터베이스 시스템이다. 이 논문은 자연어 처리 기법의 정보 검색 엔진과 브라우저에 대한 설계와 실험 결과를 소개한다. 자연어 문서에 대한 정보 검색 과정은 어휘 분석, 구문 분석, 스테밍, 주제어 색인 등의 계산학적 처리를 포함한다. 많은 이미지와 이미지의 제목, 그리고 자연어로 기술된 설명 문서를 포함하는 실험적인 데이터베이스 ‘Earth and Space Science’를 통해서 자연어 문서 분석에 기반하는 정보 검색 기능을 실험하였다. 또한 디지털 도서관 환경에서의 멀티미디어 정보 검색 내용 기반의 이미지 검색 엔진과 병행하는 정보 검색 시스템으로서의 가능성을 보여준다.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2004년도 춘계학술발표대회 논문집
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• pp.136-140
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• 2004

This study starts from the premise that future elementary school should be designed based on ecological approach. In order to restore the emotionality of children, school should provide and protect our natural environment by greening and energy saving. The research was conducted in Osaka and Busan to analyze the present condition of elementary schools in terms of ecology. The shared spaces such as halls, corridors, stairs and rest areas of fourteen schools were chosen and analyzed by the design analysis list. The list included the guidelines including greening, lighting, heating and cooling, ventilation and use of materials. The results showed that Korean schools require void space for more natural lighting, ventilation and insulation, while Japanese schools have problems in use of environmentally friendly materials, natural lighting and interior greening. This study reveals that ecological approach including greening and natural lighting should be considered in future elementary school design to make the school environment more agreeable and economical.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2006년도 추계학술발표대회 논문집
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• pp.183-186
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• 2006

The growth in human has a close relationship with circumstances and there are two different types of form as a method. One of them Is a great influence of which the environment has a certain effect to human and that is called environmental effect. The other one Is a great reaction of human against the environment which is environmental experience. Human's being loved nature and conservation of nature as a living condition have already processed out for a long time. However, in these days, it is different that a special emphasis on the conservation of nature is being destroyed and it Is perceived the principal of the destruction is human itself. The Museum of Natural Environment has no doubt in a relation with conservation of nature. The main subject of this thesis Is to restore the disappearing beauty in natural environment, an importance of resources in general needs and a change in futuristic perceptions against preservation of the species. Therefore, to produce a complexity in a combination with education and entertainment to a water resource as a main theme is now relieved from its original deteriorated public information center with its simpleness. It Is purposed to secure a cultural space for a community activity and regional peculiarities, dams and lakes, localities of rivers as a main theme to specify their details, to maximize its educational space furtherance with a value as a tourist resource in particular.

• 한국태양에너지학회 논문집
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• 제30권2호
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• pp.87-95
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• 2010

This study analyzed the performance of solar chimney system for natural ventilation in underground space. A mathematical model of the solar chimney was proposed in order to predict its performance under varying parameters and Korea climatic condition. Steady state heat transfer equations were set up using a energy balanced equations and solved using a inverse matrix method. Numerical simulation program to analyze system was developed by using MATLAB. As the results, the ventilation performance of the solar chimney was determined by the temperature difference of air channel and inlet, and the temperature difference was influenced by insolation, stack height and distance of air gab. Also the solar chimney system can provide $262.9m^3/h$ of annual average ventilation rate. Because seasonal differences of ventilation rate was calculated within 25%, the solar chimney system can be used for every season in Korea climatic condition. Through this study, performance of solar chimney system for natural ventilation was verified by numerical method. Consequently, the solar chimney system is proved to be effective device for natural ventilation utilizing at all times, and the additional studies should be made through the experimental method for imagineering and commercialization.

• 대한원격탐사학회지
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• 제33권4호
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• pp.377-390
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• 2017

Space-based Synthetic Aperture Radar (SAR) observations have been widely and successfully applied to acquire invaluable temporal and spatial information on wetlands, which are unique environments and regarded as important ecosystems. One of the best studied wetland area is Everglades, which is located in southern Florida, USA. As a World Heritage Site, the Everglades is the largest natural and subtropical wilderness in the United States. The Everglades wetlands have been threatened by anthropogenic activities such as urban expansion and agricultural development, as well as by natural processes, as sea level changes due to climate change. In order to conserve this unique wetland environment, various restoration plans have been implemented. In this review paper, we summarize the main studies using space-based SAR observations for monitoring the Everglades. The paper is composed of the following two sections: (1) review of backscattered amplitude analysis and observations, and (2) review of interferometric SAR (InSAR) analysis and applications. This study also provides an overview of a wetland InSAR technique and space-based SAR sensors. The goal of this review paper is to provide a comprehensive summary of space-based SAR monitoring of wetlands, using the Everglades wetlands as a case study.

• 한국조경학회지
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• 제27권5호
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• pp.48-56
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• 2000

This study aims to find out the norms and principles reflected in the spatial organization of royal tombs in the Chosun Dynasty through the modern interpretation of traditional oriental philosophy theory. We examined the characteristics of royal tomb sites including Jeshil(Shrine), Hongjunmun, tomb mound, ponds, and attached buildings employing an analysis of the spatial formation and landscape. This study covered 36 tombs of kings and queens in the Chosun Dynasty. The entire layout of royal tombs, including annexed buildings, was informal in may cases. This was due to following the natural contour rather than adhering to certain philosophical principles. The royal tomb site is divided into three zones. Jeshil and pond constitute a space for living people, visitors. Secondly, the semi-scared space includes the space from Hongjunmun to the entrance to the Chungjaka. The last space is for the dead, from the back of Chungjakak to tomb mound. This is in line with the layout of palaces of the Chosun Dynasty which is characterized by "three gates and three zones": outer yard-court yard- back yard. The size of the space for holding memorial ceremonies, from Hongjunmun to the Chungjakak entrance, was set at 900m until the early Chosun Dynasty. Since that time the distance varied according to the land topography due to the influence of metaphysics. It can be summarized that the spatial organization of royal tombs in the Chosun Dynasty is based on the Confucianism value, the natural contour of the site, and inner spiritual value.ual value.

• 토지주택연구
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• 제11권3호
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• pp.39-48
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• 2020

Gamcheon village was a poor village in the past, but it recently has boomed as a representative tourists' attraction in the region. Its unique topography and history have played a significant role in the town's growth as a famous tourists' attraction. The factors contributed decisively to the formation of a special spatial structure there. In the process of the town's rapid development as a tourists' destination, however, the tourism overflowed. As such, the interests of the residents and the tourists conflicted, and the segregation between the two has augmented. These gaps seem to have enormously distorted the perception of the spaces as much as they have seriously distracted the existing traffic circulations in the village. The purpose of this study is to identify the differences in spatial perception of both residents and tourists in the Gamcheon village. For the purpose, it assumes the residents' natural movements and the tourists' purposeful movements, and they are analyzed by the space syntax. The major findings are that the circulations of the residents and the tourists in the village are clearly separated and that the two groups perceive the same space completely differently. This confirms the fact that even the same space could be recognized and used in a totally different way depending on the users' purposes.

• 대한수학회지
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• 제52권6호
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• pp.1287-1303
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• 2015

The Hausdorff topology induced by a fuzzy metric space under more weak assumptions is investigated in this paper. Another purpose of this paper is to obtain the Banach contraction theorem in fuzzy metric space based on a natural concept of Cauchy sequence in fuzzy metric space.

• Korean Journal of Mathematics
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• 제6권1호
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• pp.47-66
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• 1998

In this paper, we introduce an $L_p$ analytic Fourier-Feynman transformation, show the existence of the $L_p$ analytic Fourier-Feynman transforms for a certain class of cylinder functionals on an abstract Wiener space, and investigate its interesting properties. Moreover, we define a convolution product for two functionals on the abstract Wiener space and establish the relationships between the Fourier-Feynman transform for the convolution product of two cylinder functionals and the Fourier-Feynman transform for each functional.