• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2005년도 춘계 학술발표대회 논문집
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• pp.108-109
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• 2005

• 대기
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• 제24권3호
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• pp.331-341
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• 2014

In this study, the effects of building-roof cooling on scalar dispersion in three-dimensional street canyons are investigated using a computational fluid dynamics (CFD) model. For this, surface temperature of building roof is systematically changed and non-reactive pollutants are released from street bottom in urban street canyons with the aspect ratio of 1. The characteristics of flow, air temperature, and non-reactive pollutant dispersion in the control experiment are analyzed first. Then, the effects of building-roof cooling are investigated by comparing the results with those in the control experiment. In the control experiment, a portal vortex which is a secondary flow induced by ambient air flow is formed in each street canyon. Averaged air temperature is higher inside the street canyon than in both sides of the street canyon, because warmer air is coming into the street canyon from the roof level. However, air temperature near the street bottom is lower inside the street canyon due to the inflow of cooler air from both sides of the street canyon. As building-roof temperature decreases, wind speed at the roof level increases and portal vortex becomes intensified (that is, downdraft, reverse flow, and updraft becomes stronger). Building-roof cooling contributes to the reduction of average concentration of the non-reactive pollutants and average air temperature in the street canyon. The results imply that building-roof cooling has positive effects on improvement of thermal environment and air quality in urban areas.

• 한국지리정보학회지
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• 제2권3호
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• pp.35-45
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• 1999

본 연구는 Landsat TM 영상자료를 이용한 표면온도와 NDVI의 추출을 통해서 대구광역시의 열섬분포패턴과 녹지활력도를 평가하고자 하며, 아울러 녹지의 열섬완화 효과를 정량적으로 설명하기 위해서 토지피복분류를 기준으로 한 표면온도와 NDVI의 상관성을 분석하였다. 연구결과에 따르면, 자연식생으로 피복된 산림의 경우는 NDVI가 높고, 표면온도가 낮은 곳에 분포하고 있는 반면에, 피복상태가 불투수층의 인공포장재료로 구성된 도시역은 NDVI가 낮고, 표면온도가 높은 곳에 분포하고 있는 것으로 분석되었다. 이는 토지피복상태에 따른 표면온도의 차이가 인공 포장면의 증가에 따른 도시열섬효과의 간접적인 발생 원인임을 증명하는 것으로서, 향후 도시계획을 위한 녹지계획 수립시에는 열섬분포 패턴에 관한 인자가 중요하게 고려되어져야 할 것으로 사료된다.

• 한국환경과학회지
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• 제16권5호
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• pp.603-610
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• 2007

Recent urban sprawl has destroyed various kinds of green space in tile city. It has affected duality of people's life in the city, as well as urban ecosystem. Recent study shows the possibilities of roofs as green spaces in urban central site where the land costs are generally high. This research focuses on Jung-Gu district in Daegu Metropolitan city as a study area and calculates possible area of green roof using 2002 Autocad program based on aerial photographs and land registration maps. And the purpose of this research is to analyze environmental and economic effects of green roof. The environmental effects are as follows. It is expected that $91,106m^2$ green spaces, 12.13 % of study site, will be added if green roof is performed in the study site. It is assumed that the expanded areas could reduce the highest temperature to $0.5-1.0^{\circ}C$ during the summer in terms of environmental effect. And the following shows the economic effects. If green roof and greening urban central site are created as a same size of $91,106m^2$, it will be expected that the costs of green roof will be much more in-expensive than about 98 billions won. It will be also found that the expense of cooling energy can be saved out about 8 millions won per day in summer, if grass planting is accomplished on the possible areas of green roof in the study site. Therefore, it is desirable to take legal supports such as enacting regulations to activate green roof for more environmental and economic effects. For instance, green roof for public institutions, school and model area selection are desirable method to publicize the effect of greening program for citizen's participation.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.595-598
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• 2007

Urban storm water collection and conveyance systems are critical components of the urban infrastructures. During a storm event, street grate inlets are usually loaded with debris by the first-flush runoff volume. Grate inlets are subject to clogging effects. Effective interception area of grate inlets was decreased by clogging. It also decreased the interception capacity of grate inlets and increased the inundation area in street. Therefore, it is necessary to analyze the clogging characteristics and interception capacity change by clogging for appropriate design and management of grate inlets. In this study, field survey was executed to investigate debris and clogging pattern of grate inlet in 9 areas. The clogging factor with consideration of urban area characteristics was estimated with the field survey results.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.696-701
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• 2002

This paper describes some results of change detection in Tokyo metropolitan area, Japan , using the Landsat TM data, and methods to quantify the ground cover classes. The changes are analyzed using the measures of not only conventional spectral classes but also a set of landscape indices to describe spatial properties of ground cove types using fractal dimension of objects, entropy in the specific windows defining the neighbors of focusing locations. In order eliminate the seasonal radiometric effects on TM data, an automated class labeling method is also attempted. Urban areas are also delineated automatically by defining the boundaries of the urban area. These procedures for urban change detection were implemented by the unified image computing methods proposed by the author, they can be automated in coherent and systematic ways, and it is anticipated to automate the whole procedures. The results of this analysis suggest that Tokyo metropolitan area was extended to the suburban areas along the new transportation networks and the high density area of Tokyo were also very much extended during the period between 1985 and 1995.

• 한국환경과학회지
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• 제6권5호
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• pp.437-449
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• 1997

To predict diffusion and movement of k pollutants In coastal urban region a numerical simulation shouts be consider atmospheric flow field with land-sea breeze, mountain-valley wand and urban effects. In this study we used Lagrangian [article dispersion method In the atmospheric flow field of Pusan coastal region to depict diffusion and movement of the Pollutants emoted from particular sources and employed two grid system, one for large scale calculating region with the coarse mesh grid (CMG) and the other for the small region with the One mesh 914 (FMG). It was found that the dispersion pattern of the pollutants followed local circulation system in coastal urban area and wale air pollutants exhausted from Sasang moved Into Baekyang and Jang moutain, air pollutants from Janglim moved into Hwameong-dong region.

• Smart Structures and Systems
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• 제17권2호
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• pp.257-274
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• 2016

The nonlocal static bending, buckling, free and forced vibrations of graphene nanosheets are examined based on the Kirchhoff plate theory and Taylor expansion approach. The nonlocal nanoplate model incorporates the length scale parameter which can capture the small scale effect. The governing equations are derived using Hamilton's principle and the Navier-type solution is developed for simply-supported graphene nanosheets. The analytical results are proposed for deflection, natural frequency, amplitude of forced vibration and buckling load. Moreover, the effects of nonlocal parameter, half wave number and three-dimensional sizes on the static, dynamic and stability responses of the graphene nanosheets are discussed. Some illustrative examples are also addressed to verify the present model, methodology and solution. The results show that the new nanoplate model produces larger deflection, smaller circular frequencies, amplitude and buckling load compared with the classical model.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제2호
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• pp.164-170
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• 2004

Suburban green space is an important component part of urban ecological system, the third largest space between urban center and peripheral countryside. Because of the specific regional location of the suburban green space, it differs from the green space in the center of the city in the respects of construction and planning. Anyhow, it has the features of less investment, quicker efficiency, free and easy management and good ecological effects. The writer of this paper holds that urban ecological construction should be planned rationally and laid out in an overall way under the prerequisite of making full use of and protecting local species so as to further extend the green ecological space at urban periphery, to create dense green surroundings, and to explore a way for ecological construction to develop in a scientific, effective and healthy way.

• 지역연구
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• 제35권1호
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• pp.3-18
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• 2019

도시 스프롤 현상은 녹지와 오픈스페이스의 잠식, 교통 혼잡 및 대기오염의 증가, 중심도시 쇠퇴의 촉진, 사회적 자본의 감소, 도시기반시설 비용에 대한 납세부담의 형평성 등 부정적 효과로 인해 비판을 받아왔다. 이 연구는 미국 대도시 지역에서 확인되는 도시 스프롤 특성과 다른 것으로 알려진 한국 수도 지역에서의 도시의 무질서한 확장을 측정한다. 특히 이번 연구에서는 수도권 지역이 교외지역의 저밀도 주택개발 확대로 중심도시의 쇠퇴 경험 여부를 조사한다. 인구밀도의 스프롤 지수, 인구 변화에 대한 도시화 지역의 변화 비율, 인구밀도 변화율 등 세 가지 척도를 채택하였으며, 도시 스프롤 현상을 측정하기 위해 GIS 지도와 서술적 분석을 사용하여 중심 도시의 쇠퇴와 교외지역의 개발 패턴의 특성을 조사하였다. 그 결과, 한국의 수도 지역이 중앙 도시의 쇠퇴와 교외지역의 단독주택의 증가로 미국식 스프롤형식으로 이동하고 있음을 보여주며, 정책 입안자들이 도시스프롤과 미국 대도시들이 겪고 있는 도시스프롤의 부정적 영향을 예방하기 위해 성장관리 전략을 개발할 필요가 있음을 나타낸다.