• 국토계획
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• 제54권2호
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• pp.93-108
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• 2019

This study examines the relationship between three-dimensional urban built environment and urban surface temperature using LANDSAT 8 satellite image data in Seoul city. The image was divided into 600m×600m grid units as an unit of analysis. Due to the high level of spatial dependency in surface temperature, this study uses spatial statistics to take into account spatial auto-correlation. The spatial error model shows the best goodness of fit. The analysis results show that the three-dimensional built environment and transport environment as well as natural environment have statistically significant associations with surface temperature. First, natural environment variables such as green space, streams and river, and average elevation show statistically significant negative association with surface temperature. Second, the building area shows a positive association with surface temperature. In addition, while sky view factor (SVF) has a positive association with surface temperature, surface roughness (SR) shows a negative association with it. Third, transportation related variables such as road density, railway density, and traffic volume show positive associations with surface temperature. Moreover, this study finds that SVF and SR have different effects on surface temperature in regard to the levels of total floor areas in built environment. The results indicate that interactions between floor area ratio (FAR) and three-dimensional built environmental variables such as SVF and SR should be considered to reduce urban surface temperature.

• Wind and Structures
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• 제22권4호
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• pp.503-524
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• 2016

The suitability of Computational Fluid Dynamics (CFD) simulations on the built environment for the purpose of estimating average roughness characteristics and for studying wind flow patterns within the environment is assessed. Urban models of various levels of complexity are considered including an empty domain, array of obstacles arranged in regular and staggered manners, in-homogeneous roughness with multiple patches, a semi-idealized built environment, and finally a real built environment. For each of the test cases, we conducted CFD simulations using RANS turbulence closure and validated the results against appropriate methods: existing empirical formulas for the homogeneous roughness case, empirical wind speed models for the in-homogeneous roughness case, and wind tunnel tests for the semi-idealized built environment case. In general, results obtained from the CFD simulations show good agreement with the corresponding validation methods, thereby, giving further evidence to the suitability of CFD simulations for built environment studies consisting of wide-ranging roughness. This work also provides a comprehensive overview of roughness modeling in CFD-from the simplest approach of modeling roughness implicitly through wall functions to the most elaborate approach of modeling roughness explicitly for the sake of accurate wind flow simulations within the built environment.

• 한국태양에너지학회 논문집
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• 제39권6호
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• pp.67-82
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• 2019

This study aims to examine the impacts of built environmental features on the nocturnal and diurnal temperatures during the heat wave season in Gwangju, Korea. Built environmental measures are summarized at micro-scale level, such as 50 meters and 100 meters from temperature monitoring spots. Regressing the built environment on nocturnal and diurnal temperatures, we estimate how the artificial constructs contribute to temperature either day and night times. We found that impervious surface ratio is positively and negatively associated with nocturnal and diurnal temperatures, respectively. Buildings and structures tend to construct high thermal mass and absorb heat during day time and emit it for the night time. This property contributes to the nocturnal temperature model. On the other hand, urban areas with more vertical structure tend to block sun radiation more than rural, and it is more likely to find the negative relationship between impervious surface ratio and the diurnal temperatures.

• 지역연구
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• 제40권2호
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• pp.107-130
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• 2024

도시의 지표면 기온 변화는 도시민의 열 쾌적성, 에너지 소비, 나아가 건강에 영향을 미치는 주요한 환경요인이다. 많은 연구가 도시 지표면 기온과 도시 건조환경(built-environment) 형태 간의 관계를 탐색해 왔으나 대부분 극궤도위성 자료를 사용해 정오 시간대 기온만을 분석하였다. 본 연구는 다양한 시간대 지표면 기온을 관측하는 ECOSTRESS 위성 자료를 활용하여 서울시 여름철 지표면 기온의 주간 변동을 탐색하였으며 기온 변동이 건조환경 유형별로 차별적으로 나타나는지 분석하였다. ECOSTRESS는 2018년 발사된 NASA 위성으로 점진 변화 궤도를 운항하며 다양한 시간대 지표면 온도를 70m 고해상도로 관찰한다. 본 연구는 2019~2022년 이른 오전(6:25AM)과 늦은 오후(5:26PM)에 걸친 자료를 수집하여 서울시 지표면 온도의 시계열 자료를 구축하였다. 환경 특성을 반영하는 녹지, 수면, 건축 형태(건폐율, 용적률, 높이) 데이터를 기반으로 계층적 군집분석을 실시해 8가지 건조환경 유형을 도출하였으며, 유형별 온도변동 특성을 비교하였다. 각 유형은 저층고밀거주지(low-rise compact), 저밀아파트단지(low-BCR Apt.), 강변 중고층 주거단지(Riverside Mid-rise Apt.), 중고층 용도혼합지역(mid-to-high-rise mixed use), 고층고밀지역(high-rise compact), 초고층빌딩(skyscrapers), 산림, 수면(하천)을 나타내었다. 분석 결과, 지표 기온의 공간적 격차는 새벽 이후 증가하여 정오(12:04)에 극대화된 뒤 다시 감소하였으며, 기온 변화가 급격한 지역과 안정적인 지역이 구분되었다. 저층 고밀 거주지와 고층 고밀지역의 경우 기온이 빠르고 높게 증가하여 기온변동성이 높았고, 저밀 아파트단지는 기온이 온화하고 완만하게 증가하며 기온 변동성이 낮았다. 건조환경 유형 간 평균기온의 서열은 시간별로 변화하지 않고 유지되었다. 이러한 결과는 폭염과 일교차 증가에 적응할 수 있는 도시형태에 시사점을 제공한다.

• 보건교육건강증진학회지
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• 제30권4호
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• pp.87-97
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• 2013

Objectives: Recent movements in urban planning propose a promotion of health condition as one of its emerging topics as growing body of evidence suggests that individual health is correlated with the built environment. The concept of healthy city was introduced in Korea and many local governments were tried to implement relevant policies. However, empirical studies were insufficient for understanding the relationship between health and the built environment. Most studies and policies were viewed and implemented from public health perspective. The purpose of this study is to estimate a value of healthy city as an activity-friendly environment. Methods: The 195-respondent survey data in Seoul Metropolitan Area was used for estimating the perception of healthy cities. Results: Survey results reported that more than 90% of respondents did walking and/or biking regularly. Moreover, they were willing to pay won3,695 per month for creating healthy cities. Conclusions: This study confirmed that the consideration of built environmental factor was necessary in policies of healthy city. This can offer insights into how to manage and develop the policies of healthy city to help promote individual health conditions.

• Structural Engineering and Mechanics
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• 제39권2호
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• pp.187-206
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• 2011

This paper uses dynamic computer simulation techniques to develop and apply a multi-criteria procedure using non-destructive vibration-based parameters for damage assessment in truss bridges. In addition to changes in natural frequencies, this procedure incorporates two parameters, namely the modal flexibility and the modal strain energy. Using the numerically simulated modal data obtained through finite element analysis of the healthy and damaged bridge models, algorithms based on modal flexibility and modal strain energy changes before and after damage are obtained and used as the indices for the assessment of structural health state. The application of the two proposed parameters to truss-type structures is limited in the literature. The proposed multi-criteria based damage assessment procedure is therefore developed and applied to truss bridges. The application of the approach is demonstrated through numerical simulation studies of a single-span simply supported truss bridge with eight damage scenarios corresponding to different types of deck and truss damage. Results show that the proposed multi-criteria method is effective in damage assessment in this type of bridge superstructure.

• Asian Journal of Innovation and Policy
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• 제9권1호
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• pp.79-94
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• 2020

This study reviews how an aging society can be connected to the urban-built environment, transportation system, infrastructure, and climate change topics from the perspective of policy and innovation in science and technology. Each topic was described with the aging society that we will encounter in the near future. Based on the expected discussions, we suggested how policy and technological innovations may interact with the new emerging society. Especially, digital transformation is expected to hyper-connect the aging society beyond physical barriers where numerous policies and innovations in science and technology shed light on the elderly population. We observe, however, that this cannot be achieved only by the government sector; rather, municipal governments and local communities, as well as private sectors, all together need to prepare for the new society of the aging population. Furthermore, an ideal approach is to accommodate multidisciplinary studies that can address the policy and technological innovations simultaneously and collectively. By doing so, we can minimize the negative impacts when an aging society approaches.

• 대한건축학회논문집:계획계
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• 제35권1호
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• pp.117-125
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• 2019

The purpose of this study is to examine urban built environments associated with the walking behavior in order to identify the problem of urban infrastructure from the perspective of Universal design theory. Using the walkability criteria developed based on the findings of previous studies on Universal design theory and walking environment, the urban built environments in old town area of Seoul were evaluated. The results of the evaluation indicated that the pedestrian infrastructure in the study area had several shortcomings to improve in order to provide walking-friendly environments. First, the pedestrian infrastructure for visually impaired people were severely limited. Second, walking traffics in large portion of the street networks were interrupted by a variety of obstacles such as parked cars, signboards, and illegal street shops. Third, there were certain areas where the quality of pavement was not properly managed. In summary, this study provides an empirical data to understand the current situation of pedestrian infrastructure in the urban areas. Improvement of pedestrian infrastructure is needed to address the issues related to the mobility of the disabled people. It is also recommended to construct the GIS data on walking environment in order to develop and mange a long-term public investment plan for walking-friendly urban environments.

• 한국ITS학회 논문지
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• 제22권4호
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• pp.114-131
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• 2023

개인형 이동수단의 이용이 활성화됨에 따라, 관련한 PM 사고도 급격하게 증가하였다. 이러한 사고 증가에 대응하기 위해, 2021년 5월 13일 정부에서는 관련 규정을 강화하였지만, PM 가해사고의 증가 추이는 피해사고의 증가 추이보다 크게 감소하지 않았다. 이러한 PM 가해사고의 대부분은 보행자와의 충돌 사고로, 보행자들의 안전이 위협받고 있는 것을 알 수 있었다. 이에 본 연구에서는 PM 대 보행자 충돌사고를 중점적으로 규제 및 기상환경, 도시건조환경 특성 등을 반영하여, PM 대 보행자 교통사고 심각도에 영향을 미치는 요인들을 분석하였다. 2020년부터 2021년 간 서울시에서 발생한 PM 대 보행자 교통사고를 수집하였으며, 이항 로지스틱 회귀분석을 활용하여 분석을 수행하였다. 주요 분석결과를 통해 정책적 시사점을 도출하였다.

• 한국대기환경학회지
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• 제33권6호
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• pp.583-592
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• 2017

A method is proposed for locating the heat sources from temperature observations, and its applicability is investigated for urban thermal environment simulations. A Lagrangian particle dispersion model, which is originally built for simulating the pollutants spread in the air, is exploited to identify the heat sources by transporting the Lagrangian heat particles backwards in time. The urban wind fields are estimated using a diagnostic meteorological model incorporating the morphological model for the urban canopy. The proposed method is tested for the horizontally homogeneous urban boundary layer problems. The effects of the turbulence levels and the computational time on the simulation are investigated.