• 한국환경복원기술학회지
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• 제17권2호
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• pp.1-14
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• 2014

The purpose of this study is to identify the efficiency of LID technologies for controlling non-point source pollution from urban areas. The recent technical responses to managing water resource and urban areas according to the influence of climate change is an important national policy, along with green growth. Through various reference studies reasonable ways to consider a wholistic plan on urban-eco-friendly river management, the Low Impact Development (LID) as the adequate river management method is being undertaken in foreign countries to technically apply to urban plans. However, the LID is at the initial stage in Korea, with no specific studies implemented. Thus, this study explored whether LID technologies can be efficient measures to control non-point source pollution on the cost side. Ulsan's Namgu and Bukgu have been chosen as case studies that illustrate the efficiency of the LID technologies. On investigation, if LID technologies are designed properly, the efficiency of them is expected to higher than that of sewage treatment plant.

• 대한토목학회논문집
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• 제39권1호
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• pp.227-237
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• 2019

도시계획 및 설계의 공간 개념에 있어 현대도시는 정체성을 기반으로 모든 공간은 차이가 나는 장소로 이루어져 있다는 시각으로 접근한다. 이렇듯 본 연구에서는 도시를 이루고 있는 개별 공간간의 차이에 주목하여 이질적 이미지를 분석하고, 레지빌리티 측정을 통해 이질성을 띄는 각 공간의 이미지에 반응하는 물리적, 행태적 요소를 도출하였다. 그 결과 부산시의 도시공간은 폐쇄성, 개방감, 동적+폐쇄성, 동적+개방감, 정적 등의 이질적 이미지를 가지며, 각각의 이미지를 강하게 느끼게 하는 레지빌리티 요소로 폐쇄성에는 고밀 고층건축물, 거주, 업무의 요소, 개방감은 수공간, 산책, 조망의 요소, 동적&폐쇄성은 산업활동의 요소, 동적&개방감은 오픈스페이스, 수공간, 수영의 요소, 정적 이미지는 녹지, 산책, 머무름의 요소로 나타났다.

• 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.

• Environmental Engineering Research
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• 제18권3호
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• pp.199-208
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• 2013

This study intended to develop an integrated governance model and find measures to manage nonpoint source (NPS) pollutions in watershed management. To reach this goal, this study has analyzed NPS pollution management policies in Korea and has employed statistical methods such as expert Delphi survey, analysis of variance, and factor analysis. As a result, this study has found that the favored basic organization form was a private-public cooperative council. The necessary governance-based NPS pollution management measures determined through this study are as follows: to build collaboration mechanisms including those related to motivation provision, trust building, capacity building, and making optimal regulations; to employ financial resources based on principles such as 'polluter-pays', 'recipient-pays', and 'general-tax-source'; and to develop several programs, including system improvement, pilot and management projects, and publicity.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.294-301
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• 2005

Ground response analysis is one of the most important and most commonly encountered problems in geotechnical earthquake engineering. It is a prerequisite step for liquefaction assessment of saturated soil or the pseudo-static and dynamic analysis of geotechnical structures. A number of techniques have been developed for ground response analysis. In this study, ground response analyses were performed using the computer programs that are currently being used domestically. From these analyses, the analysis techniques applied to the programs were compared and analyzed. The results of ground response analyses were compared as follows: 1) 1-dimensional analysis vs. 2-dimensional analysis; 2) equivalent linear analysis vs. nonlinear analysis.

• 한국태양에너지학회 논문집
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• 제29권3호
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• pp.51-58
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• 2009

Recently, many social, economical and political problems have occurred in the field of urban energy supply because of the depletion of fossil fuels and the international climate change agreements and the current energy-related laws focus on individual buildings which makes them difficult to implement. Also, the policies for energy savings have increased day by day, but it is difficult to establish efficient urban plan because of lack of integrated policies and institutions. Current legal systems for urban plan does not cover domestic and international climate change agreements, energy related industry's structural changes and other environmental problems such as embodied energy and global warming. This paper tries to investigate current conditions of legal system to provide fundamental materials for improving energy conservation in urban plan.

• Environmental Engineering Research
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• 제24권1호
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• pp.107-116
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• 2019

Nitrogen removal, nitrous oxide ($N_2O$) emission and microbial community in sequencing batch and continuous-flow intermittent aeration processes were investigated. Two sequencing batch reactors (SBRs) and two continuous-flow multiple anoxic and aerobic reactors (CMRs) were operated under high dissolved oxygen (DO) (SBR-H and CMR-H) and low DO (SBR-L and CMR-L) concentrations, respectively. Nitrogen removal was enhanced under CMR and low DO conditions (CMR-L). The highest total inorganic nitrogen removal efficiency of 91.5% was achieved. Higher nitrifying and denitrifying activities in SBRs were observed. CMRs possessed higher $N_2O$ emission factors during nitrification in the presence of organics, with the highest $N_2O$ emission factor of 60.7% in CMR-L. SBR and low DO conditions promoted $N_2O$ emission during denitrification. CMR systems had higher microbial diversity. Candidatus Accumulibacter, Nitrosomonadaceae and putative denitrifiers ($N_2O$ reducers and producers) were responsible for $N_2O$ emission.

• 대한원격탐사학회지
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• 제37권4호
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• pp.665-685
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• 2021

This study focused on the a 20-year evaluation of the dynamism of critical thermal anomalies in Busan metropolitan area prompted by unusual infrastructural development and demographic growth rate. Archived Landsat thermal data derived-LST was the major input for UTFVI and hot spot analysis (Getis-Ord Gi^*). Results revealed that the surface urban heat island-affected area has gradually expanded overtime from 23.32% to 32.36%; while the critical positive thermal anomalies (level-3 hotspots) have also spatially increased from 19.88% in 2000 to 23.56% in 2020, recording a net LST difference of > 5℃ between the maximum level-3 hotspot and minimum level-3 coldspot each year. It is been observed that thermal conditions of Busan have gradually deteriorated with time, which is potentially inherent in the rate of urban expansion. Thus, this work serves as an eye-opener to powers that be, to think and act constructively towards a sustainable thermal conform for city dwellers.

• Geomechanics and Engineering
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• 제34권4호
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• pp.341-380
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• 2023

This study evaluates the seismic fragilities in fill slopes in South Korea through parametric finite element analyses that have been barely investigated thus far. We consider three slope geometries for a slope of height 10 m and three slope angles, and two soil types, namely frictional and frictionless, associated with two soil states, loose and dense for frictional soils and soft and stiff for frictionless soils. The input ground motions accounting for four site conditions in South Korea are obtained from one-dimensional site response analyses. By comparing the numerical modeling of slopes using PLAXIS^2D against the previous studies, we compiled suites of the maximum permanent slope displacement (D_max) against two ground motion parameters, namely, peak ground acceleration (PGA) and Arias Intensity (I_A). A probabilistic seismic demand model is adopted to compute the probabilities of exceeding three limit states (minor, moderate, and extensive). We propose multiple seismic fragility curves as functions of a single ground motion parameter and numerous seismic fragility surfaces as functions of two ground motion parameters. The results show that soil type, slope angle, and input ground motion influence these probabilities, and are expected to help regional authorities and engineers assess the seismic fragility of fill slopes in the road systems in South Korea.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.387-396
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• 2020

Wearable biosensors have the potential to non-invasively and continuously monitor seniors' stress in their daily interaction with the urban environment, thereby enabling to address the stress and ultimately advance their outdoor mobility. However, current wearable biosensor-based stress detection methods have several drawbacks in field application due to their dependence on batch-learning algorithms. First, these methods train a single classifier, which might not account for multiple subjects' different physiological reactivity to stress. Second, they require a great deal of computational power to store and reuse all previous data for updating the signle classifier. To address this issue, we tested the feasibility of online multi-task learning (OMTL) algorithms to identify multiple seniors' stress from electrodermal activity (EDA) collected by a wristband-type biosensor in a daily trip setting. As a result, OMTL algorithms showed the higher test accuracy (75.7%, 76.2%, and 71.2%) than a batch-learning algorithm (64.8%). This finding demonstrates that the OMTL algorithms can strengthen the field applicability of the wearable biosensor-based stress detection, thereby contributing to better understanding the seniors' stress in the urban environment and ultimately advancing their mobility.