• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.32-38
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• 2020

This study summarizes test methods and evaluation methods for examining the thermal characteristics of Jeju-type ground heat exchangers (GHXs) installed on Jeju Island, and analyzes the ground temperature and thermal characteristics of ground heat exchangers installed in various regions by using thermal response tests (TRT). Jeju Island is composed of volcanic rock layers, and the groundwater flow is well developed. A Jeju-type GHX can be installed up to 30 m from groundwater level after drilling a borehole. The ground heat exchanger has a structure in which several pipes are inserted into the borehole. In order to examine the characteristics of the Jeju-type GHX, tests were conducted on ground heat exchangers installed in four places on Jeju Island (Pyoseon, Jeju, Namwon, and Hallym). As a result of the analysis of the Jeju-type ground heat exchanger, the ground circulating water temperature stabilized according to the heat injection, depending on the installed location, and was formed within one to three hours. The ground heat exchanger capacity in Hallym was highest at 73.4 kW (cooling) and 82.8 kW (heating), and the Jeju-type calculation was lowest at 34.1 kW (cooling) and 23.3 kW (heating).

• Journal of the Korean institute of surface engineering
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• v.57 no.2
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• pp.98-104
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• 2024

In order to overcome the urban heat island effect, highly functional paint is attracting attention as a promising means by shielding heat on the structure (building) surface. When a paint was prepared containing nano-sized silica particles, the heat-insulating performance was relatively higher than that of paints with other sizes. In addition, developed paints showed enhanced properties such as chemical resistance and abrasion resistance test because of the presence of nano-sized silica included in functional paint.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.1
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• pp.3-9
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• 2013

Development of housing, industrial and public lands has been a cause to increase a temperature of a city higher than that of a rural area. Knowing that, the research analyzed temperature changes in a riverside district and a coastal area depending on the land usage and climate change in the areas. Add to this, the study examined a correlation between topographic characteristics and temperature changes. According to the results, the temperature was increased by $1.80^{\circ}C$ in 2007 comparing to 2003 while the wind velocity was reduced by 0.24m/s. In addition, a more number of areas were designated as build-up areas which, in return, decreased the forested land. The analysis on the correlation reported that the riverside district has more of grassland and bare land while the coastal area has more of wooded land and grassland. The study is expected to be used as fundamental data for research on heat island effect which would be different by each regional characteristic as it proposes measures to solve the heat island effect.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.6
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• pp.27-37
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• 2019

This study focused on the possibility of reducing the cooling load through the change of micro climate in the outdoor space during summer season. This study proposes an efficient planning model by comparing the effects of urban heat island mitigation through wind path planning, outdoor space vegetation, and exterior material change by using the basic model of the street-oriented block housing proposed in the previous research by the same author. As a result, the most effective wind path planning strategy in the street-oriented block housing was the change of the air flow through the mass height adjustment. When the tall building masses were staggered and arranged in a balanced manner, the overall wind environment could be improved. The greater the height difference between low and high masses, the better the air flow was shown. It was also important to arrange the building masses so that the inlet of the main wind was open and to allow the external space to connect to the adjacent block to create a continuous flow. The change of outdoor space vegetation and flooring, and the formation of wind paths through the opening of lower part also showed the effect of heat island reduction. In addition, the change of PMV in summer was the biggest influence of shadow by tall building mass. Attention should be paid to the fact that high-albedo exterior materials are adversely affected by multiple reflections in dense street-oriented block housing. The use of albedo of the exterior material showed that it is necessary to pay attention to apply in the high density block housing. This is attributed to the rise of the temperature due to the absorption of energy into the low-albedo flooring, where the high-albedo exterior causes multiple reflections.

• Journal of Environmental Impact Assessment
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• v.32 no.3
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• pp.176-186
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• 2023

Urban Heat Island (UHI) is caused by an energy imbalance in urban areas, where building design and land cover contribute to its amplification. To mitigate UHI, increasing green space is one of the well known and the most effective approach. This study aims aimed to identify specific components of green spaces that lower temperatures and demonstrate the cooling effects based on their size and composition. Forests within green spaces have had a greater impact on temperature reduction due to shading and blocking solar radiation. Although lakes also contributed to temperature reduction, the effect to cooling intensity was not significant. The cooling distance does not depended on green space size or composition. The study emphasizes that initial temperature has a strongerinfluence on cooling intensity than green space size, highlighting the importance of vegetation type within green spaces to achieve a cooling effect. These findings provide valuable insights for urban planning and the design of green spaces to mitigate the effects of the urban heat island.

• Journal of Environmental Science International
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• v.16 no.1
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• pp.73-79
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• 2007

The purpose of this study is to clarify the effect of mountain-valley wind on heat island formed in urban area which is located around valley mouth. The meteorological observations were carried out over the Dalbi-valley under a clear summer pressure patterns, and some consideration were tried from the results. In order to make clear the climatological characteristics and air-mass modification process of the mountain-valley wind over the valley, the meteorological observations were done simultaneously at two points. The observational points were located at the breast and valley mouth parts, respectively. The results were as follows: First, it was found that the valley wind was observed through the daytime, and it was replaced by a mountain wind after sunset. Second, the heat budget is also investigated with observation data. The sensible heat flux over the breast of Dalbi-valley reached to about $200 W/m^2$ during daytime, which is a little more than one third of net radiation. On the other hand, the sensible heat flux represented negative values during nighttime. But the sensible heat flux over the valley mouth covered by asphalt showed plus value(about $20{\sim}30 W/m^2$) during the nighttime.

• Journal of Environmental Science International
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• v.13 no.6
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• pp.527-535
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• 2004

As urbanization has been expanded in Korea, open spaces, such as urban parks and public sites, have been utilized for other uses, and then this bring out environmental changes for the worse. It is expected that these changes become more serious problems due to overpopulation, increasing individualism, and development of transportation. This research base on the consideration of connecting between decreasing urban green spaces and distributed green sites so as to build the substantial plan for the Green Network construction for urban heat island mitigation in Dalseo district, Daegu Metropolitan City. The result were as follow; 1) Connecting existing natural sites to the remained parks green zone made an Ideal form of Green-Network system. 2) Some school sites were selected for usable open spaces in order to build Green-Network system, and the plan connecting together with exist natural sites was suggested. 3) Moreover, the scheme of planting on the road spaces for connecting green spaces was proposed. 4) The devices of planting on the urban riverside for enhancing the role of urban stream to form green network was conceived.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.325-332
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• 2006

The purpose of this paper is to suggest practical suggestions to mitigate Urban Heat Island(UHI) problems in Daegu regarding urban surface temperature. Urban street trees's size and the relations between urban land use types and surface temperature are analysed using aerial photos, the numerical value map and Landsat TM image with special reference to Jung-gu. Total urban street tree's crown size is $156,217.6m^2$ and it is equal to 2.24% of study area. In addition, the size of 'city and residential area' is $6,681,870m^2$(95.7% of study area), which causes UHI and the total size of 'river' shows the lowest surface temperature area and 'road' and 'business and service area' are the highest surface temperature zones. Therefore, it is probable that the network between urban street trees and the lowest surface temperature areas mitigate UHI effects.

• Journal of Environmental Science International
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• v.18 no.2
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• pp.169-176
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• 2009

The present study observed temperature in order to identify factors affecting temperature by zoning and to measure the intensity of their impact on temperature. The empirical results of analyzing observed data are as follows. In order to make up for multicollinearity, a problem in multiple regression analysis, and to give more specific explanations, this study conducted factor analysis and obtained desirable data with adequacy and statistical significance. In the correlation matrix, factors decreasing temperature were planted areas, water surfaces and grasslands, and those increasing temperature were bare grounds, paved areas, and building area. According to land cover patterns, commercial areas had the highest temperature lowering effect. Through the rotated component matrix, we found that factors are grouped into those decreasing temperature, those increasing temperature, and those with low significance in increasing or decreasing temperature. In order to solve the problem of multicollinearity in multiple regression analysis, we performed factor analysis between the land use patterns and temperature and confirmed the usability of factor analysis as a new analysis method in urban heat island.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.65-75
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• 2004

This study aims to identify the degree of heat island in summer in Gwangju. For the purpose the city was classified according to use and surface components and temperature of the city for 24 hours was measured. The period of measurement was from August 11 to 13. 2003(two days). As a result of the measurement, the daily standard temperature of the central business areas and downtown areas was about $26^{\circ}C$. That of new residential areas neighboring the downtown was $25.1^{\circ}C$, and that of the outer residential areas was $23.4^{\circ}C$. In comparison with the result that temperatures of the Gwangju University playground and the Gwangju Weather Bureau were $23.1^{\circ}C$ and $23.3^{\circ}C$ respectively, the temperature of the downtown was about $2.7^{\circ}C$ Higher and that of the new residential area in downtown was about $1.8^{\circ}C$ higher. And it was demonstrated that the downtown outer road under Mt. Mudeung is a low-temperature zone. When temperature of the city was measured based on surface components, the daily standard temperature of Gwangju Stream Bok-gae area was the highest, $24.2^{\circ}C$, followed by $23.6^{\circ}C$ of the downtown stream and $22.2^{\circ}C$ of the greens (city park) and the waterside area.