• 한국태양에너지학회 논문집
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• 제28권3호
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• pp.35-44
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• 2008

In this study, the experiment of the measuring of four different types of flooring materials' thermal characteristics was conducted and examined during the summer. The experimental materials were arranged on the existing slab of the roof, and then its thermal characteristics were examined from the point of view of thermal radiation analysis. The aim of this study is ultimately to draw the fundamental data for improvements in a building's thermal function and reduce the urban heat island phenomena through optimizing the thermal characteristics of the surface covering materials of a building. The results from this study are as follows; 1) Each experimental material's albedo was calculated as 0.83 on the aluminum panel, 0.40 on the rock block, 0.37 on the wood deck and 0.21 on the concrete. It shows that the concrete material, which has the lowest short wave reflective rate, absorbed the most radiation energy and the aluminium panel has absorbed the lowest radiation energy. 2) From the each experimental object's value of the long wave radiation, the concrete material measured the highest, at $628W/m^2$, and the aluminium panel measured the lowest at $412W/m^2$. Therefore, it verifies that the experimental objects' own radiation rate determines the amount of the long wave radiation. 3) The degree of energy absorbency of a building's surface covering materials is greatly influenced by its own albedo and radiation rate, Therefore, it needs to be considered for the improvements in a building's thermal function and reducing the urban heat island phenomena. 4) According to the evaluation result of the each experimental object's overall heat transmission screening function on the roof of a building, the wooden deck is proven to be an excellent material for excluding the outside temperature differences effectively with its characteristic of low heat capacity and conduction. Also its surface temperature on the roof slab and the temperature difference during the day were both measured at low.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.100-103
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• 2009

The impermeable area on the surface of city has been increased as buildings and artificial landcover have continually been increased. Urban development has gradually decreased the green zone in downtown and alienated the city from the natural environment on outskirt area devastating the natural eco system. There arise the environmental problems peculiar to city including urban heat island phenomenon, urban flood, air pollution and urban desertification. As one of urban plans to solve such problems, green roof system is attracting attentions. The purpose of this study was to investigate the heat reduction effect according to the development of green roof system and to quantify the heat reduction effect by analyzing through simulation the heat environment before and after green roof system. For thermal environment analysis, Thermo-Render 3.0 was used that was developed by Tokyo Industrial College to simulate. The simulation showed that the heat island index before and after the development of tree-planting on rooftop changed maximum $0.86^{\circ}C$ and the surface temperature changed about $20^{\circ}C$. Only with lawn planting, heat reduction effect was great and it means that the green roof system in low-management-light-weight type is enough to see effect. The simulation identified that only lawn planting for green rooftop brought such difference and could lower the heat island index at a narrow area. It is judged that application of green roof system to wider areas might relieve urban heat island phenomenon positively.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.533-536
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• 2004

Presently, heat island phenomenon, leading towards global warming, is one of the major environmental problems. As a solution of this problem, roof and surface wall planting is considered to be effective. Accordingly, the objective of this study is to examine the effectiveness of roof planting in reducing the heat island phenomenon. The results of the study show that, planted area of the observed house roof had lower average temperature, in between $l5-20^{\circ}C,$ in comparison with that of the unplanted area of the roof.

• 한국산업융합학회 논문집
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• 제13권2호
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• pp.55-61
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• 2010

Significant air temperature increases in urban areas are known as the heat island phenomenon in a global scale. Therefore, we use CFD simulation in order to analyze quantitative effects by placing a Building and Green on the heat island phenomenon in urban area. The present study quantitatively analyzes the Urban Heat Island Effects, Outdoor air temperature, and Humidity and air flow.

• 농업과학연구
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• 제39권1호
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• pp.87-95
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• 2012

Land surface temperature (LST) is an important factor in human health, thermal environment, heat balance, global change studies, and as control for climate change. The objective of this study was to assess the influence of Urban Heat Island (UHI) Effects on the LST and NDVI in Cheongju, Korea. The aim was to evaluate the effect of urban thermal environment for LST comparison of satellite-derived and in situ measured temperature. In this study, LANDSAT TM and KOMPSAT scene were used. The results indicated that the minimum LST is observed over dense forest as about $21{\sim}25^{\circ}C$ and maximum LST is observed over industrial area of about $28{\sim}32^{\circ}C$. The estimated LST showed that industrial area, bare soils and built-up areas exhibit higher surface temperatures, while forest, water bodies, agricultural croplands, and dense vegetations have lower surface temperatures during the summer daytime. Result corroborates the fact that LST over land use/land cover (LULC) types are greatly influenced by the amount of vegetation and water bodies present. The LST of industrial area and urban center is higher than that of suburban area, so it is clearly proved that there are obvious UHIE in Cheongju.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.82-84
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• 2008

This paper presents the modeling and power quality analysis of Jeju island power system connected with wind farm, and thermal power plant. It is for indicating the influence of wind farm operation in steady and transient state in Jeju island power system during the HVDC system overhaul period. For the computer simulation, three kinds of main item are modeled, which are 67[MW] wind farm, thermal power plant and Jeju power load. To analyze the influence of the wind power generation to the Jeju power system, two kinds of simulations are carried out by using the PSCAD/EMTDC program. One is the steady state operation under the variable speed wind, and the other is the transient state operation when all of wind farms in Jeju island are disconnected from the Jeju power grid instantaneously on the rated power output. With the comparison of these results, it is useful for analyzing the power quality of Jeju power system versus wind power generation.

• 한국환경과학회지
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• 제29권12호
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• pp.1153-1170
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• 2020

With global warming and the rapid increase in urbanization accompanied by a concentration of population, the urban heat island effects (UHI) have become an important environmental issue. In this study, rooftop greening and permeable asphalt pavement were selected as measures to reduce urban heat island and applied to a simple virtual urban environment to simulate temperature change using ENVI-met. A total of five measures were tested by dividing the partial and whole area application of each measure. The results showed that the temperature range of the base experiment is 33.11-37.11 ℃, with the UTCI comfort level described as strong heat and very strong heat stress. A case applied permeable asphalt has a greater temperature difference than a rooftop greening case, the larger the area where each condition was applied, the greater the temperature change was.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권3호
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• pp.1-10
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• 2022

Most wells developed in Jeju island before the enactment of the Groundwater Management Ordinance in 2002 are vulnerable to aquifer contamination due to inflow of upper groundwater having the high concentration of nitrate nitrogen, likely due to incomplete grouting in upper section of the wells. Although these wells require entire reinstallation, it is often necessary to rehabilitate the existing wells due to various constraints. Therefore, to identified the inflow section of contaminants, the thermal level sensor (TLS) technique was firstly applied for three wells, which enables to monitor temperature variations in every 50 cm depth. Then, the grouting material was injected to the upper section to prevent the inflow of upper contaminated groundwater into the entire aquifer. By applying TLS technique, it was found that the temperature deviations in the upper groundwater inflow section decreased sharply. Moreover, both the change in the concentration of nitrate nitrogen in the rainy/dry seasons and the average concentrations were found to decrease rapidly after grouting material injection. Consequently, the application of TLS proposed in the study turned out to be appropriate to prevent aquifer contamination.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.32-38
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• 2020

본 연구는 제주도에 설치된 제주형 지중열교환기의 열적 특성을 분석하기 위해서 시험 방법 및 평가 방법을 정립하고, 열응답시험 (TRT)을 통하여 다양한 지역에 설치된 지중열교환기의 지중온도와 열적 특성을 분석하였다. 제주도는 화산암반층으로 이루어져 지하수의 유동이 잘 발달되어 있으며, 제주형 지중열교환기는 보어홀을 굴착 한 이후에 지하수 수위로 부터 30 m 까지 지중열교환기를 설치할 수 있다. 지중열교환기는 여러개의 파이프가 보어홀 내부에 삽입되는 구조로 되어있다. 제주형 지중열교환기의 특성을 살펴보기 위해 제주도 관내 4곳 (표선, 제주, 남원, 한림)에 설치된 지중열교환기에 대한 시험을 수행하였다. 분석결과 제주형 지중열교환기의 경우 열교환기에 열량을 투입 후 1 ~ 3시간 안에서 지중 순환수 온도가 안정화 되었으며, 열교환기가 설치된 지역에 따라서 투입열량에 따른 지중 순환수 온도 상승이 다르게 나타났다. 한림의 경우 지중열교환기 용량이 73.4 kW (냉방) / 82.8 kW (난방)로 가장 높게 나타났으며, 제주의 경우 34.1 kW (냉방) / 23.3 kW (난방)로 가장 작게 계산되었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.741-743
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• 2003

This study focuses on monitoring the surface UHI in a tropical city of Bangkok in both spatial and temporal dimensions based on MODIS- and TM -derived land surface temperature (LST). The spatial extension and magnitude of the surface UHI are explored for days and nights as well as its variations through the dry (least-clouded) season. Surface UHI growth between 1993 and 2002 is mapped using highresolution LANDSAT TM thermal bands. UHI patterns are, then, analyzed in association with land/vegetation covers derived from high-resolution ETM+ and ASTER satellites and ancillary data.