• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2019.08a
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• pp.252-252
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• 2019

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.11-18
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• 2000

Taegu is notorious as hot and dry summer among Korea cities. One of the most important goals of the open space planning is to ameliorate urban climate of the city. The objective of this research is to evaluate the thermal mitigation effect of the cool islands in Taegu metropolitan city. Cool islands of this paper includes parks and rivers surrounded by or adjacent to urbanized areas. Based on the analysis of the thermal band of Landsat TM at May 17, 1997, the thermal mitigation effect of open spaces in the city could be summarized as follows ; Kumho river showed the largest mitigation effect in terms of the width of mitigation zone and temperature difference. Evaporation from wide water surface and evapo-transpiration from riparian grass land could bring into results. Significant mitigation effect of parks covered with forest can be observed. The temperature range of such parks were between 19.05$^{\circ}C$ and 19.44$^{\circ}C$ However, the thermal mitigation effect of Dalsung park and Apsan park was insignificant. The small size and high percentage of hard paving of the former and the relative low density of the residential areas adjacent to the latter could be the main reason. In conclusion, the thermal mitigation effect in urban ope spaces could be detectedby the employment of thermal band data of Landsat TM and GIS buffering technique.

• Journal of the Korean Geographical Society
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• v.40
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• pp.1-13
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• 1989

The brightness temperature from NOAA AVHRR CH 4 images was examined for the metropolitan Seoul area, the capital city of Korea, to detect the characteristics of the urban heat island for this study. Surface data from 21 meteorological stations were compared with the brightness temperatures Through computer enhancement techniques, more than 20 heat islands could be recognized in South Korea, with 1 km spatii resolution at a scale of 1: 200, 00O(Fig. 3, 4 and 6). The result of the analysis of AVHRR CH 4 images over the metropolitan Seoul area can be summerized as follows (1) The pattern of brightness temperature distribution in the metropolitan Seoul area shows a relatively strong temperature contrast between urban and rural areas. There is some indication of the warm brightness temperature zone characterrizing built-up area including CBD, densely populated residential district and industrial zone. The cool brightness temperature is asociaed with the major hills such as Bukhan-san, Nam-san and Kwanak-san or with the major water bodies such as Han-gang, and reservoirs. Although the influence of the river and reservoirs is obvious in the brightness temperauture, that of small-scaled land use features such as parks in the cities is not features such as parks in the cities is not apperent. (2) One can find a linerar relationshop between the brightenss temperature and air temperature for 10 major cities, where the difference between two variables is larger in big cities. Though the coefficient value is 0.82, one can estimate that factors of the heat islands can not be explained only by the size of the cities. The magnitude of the horizontal brightness temperature differences between urban and rural area is found to be greater than that of horizontal air temperature difference in Korea. (3) Also one can find the high heat island intensity in some smaller cities such as Changwon(won(Tu-r=9.0$^{\circ}$C) and Po-hang(Tu-r==7.1$^{\circ}$~)T. he industrial location quotient of Chang-won is the second in the country and Po-hang the third. (4) A comparision of the enhanced thermal infrared imageries in 1986 and 1989, with the map at a scale of 1:200, 000 for the meotropolitan Seoul area showes the extent of possible urbanization changes. In the last three years, the heat islands have been extended in area. zone characterrizing built-up area including (5) Although the overall data base is small, the data in Fig. 3 suggest that brightness tempeautre could ge utilized for the study on the heat island characteristics. Satellite observations are required to study and monitor the impact of urban heat island on the climate and environment on global scale. This type of remote sensing provides a meams of monitoring the growth of urban and suburban aeas and its impact on the environment.

• Transactions on Electrical and Electronic Materials
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• v.15 no.1
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• pp.20-23
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• 2014

Dual phase steels have a microstructure comprising of a polygonal ferrite matrix together with dispersed islands of martensite. There are clear differences between the image quality (IQ) map of the dual phase and the corresponding ferritic/pearlitic structures, both in the as-heat treated and cold rolled conditions. Electron backscatter diffraction (EBSD) techniques were used to study the evolution substructure of steel due to plastic deformation. The martensite-ferrite and ferrite-pearlite interfaces were observed. The interface can be a source of mobile dislocations which the bands seem to originate from the martensite islands. In particular, the use of image quality is highlighted.

• KIEAE Journal
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• v.14 no.5
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• pp.123-130
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• 2014

In order for effective heat island reduction policies to be proposed, this research made use of the land usage and land coverage and Temperature of cities, Coordinate axis data within 500 meters of nationwide automatic weather stations (478 points) in order to analyze the correlation of summertime temperatures through multiple regression analysis. This research also developed a model and empirically analyzed the urban heat island reduction effect of factors that affect regional temperatures. Heat islands cause environment deterioration and therefore can harm citizens' health, and also affects the city's metabolism process. Thus in order to restrain regional temperature rises the conclusion was drawn that consideration to increase forest areas on part of land usage planning is needed. Appropriate policy measures to regulate traffic related factors are also needed to restrain regional temperature rises. In order for future heat island reduction this research proposes a way to set up more effective policies and urban sustainability improvement strategies, and is significant in that it makes use of detailed data such as land usage and land coverage, Temperature of cities, Coordinate axis in analyses.

• Journal of the Korean Solar Energy Society
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• v.35 no.4
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• pp.17-24
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• 2015

The formation of heat islands causes high energy demand for space cooling and peak cooling loads in conditioned buildings. High-temperature fluctuations on a building roof may cause mechanical stress and increase surface deterioration. Thermal energy storage (TES) systems using microencapsulated phase-change materials (MPCMs) have been recognized as one of the most advanced energy technologies for enhancing the energy efficiency and sustainability of buildings. In this study, we prepared MPCM/paint composites for mitigating the heat island effect and reducing peak temperature. In addition, we carried out thermal and physical analysis of prepared MPCM composite samples by means of SEM, FTIR spectroscopy, DSC, and TGA. Further, we evaluated the dynamic heat transfer performance of heat-storage tiles painted with 10 g of heat-storage paint. From the obtained results, we deduced that MPCM/hydrophilic paint composites are more applicable to various fields, including the building sector, than MPCM/hydrophobic paint composites. On the basis of SEM and FTIR spectroscopy results, we concluded that materials with hydrophilic properties are more compatible with MPCMs than those with hydrophobic properties. In addition, DSC analysis results revealed that MPCM/hydrophilic paint composites have better compatibility, higher latent heat capacity, and better thermal properties than other composites. TGA results showed that hydrophilic-paint-based composites have higher thermal durability than hydrophobic-paint-based composites. Finally, a lot of MPCM-loaded heat-storage tiles showed lower peak temperatures at all measurement positions.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1333-1336
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• 1998

Hydrogenated amorphous silicon(a-Si:H) films which were deposited by plasma enhanced chemical deposition(PECVD) have been recrystallized by the two-step rapid thermal annealing(RTA) employing the halogen lamp. The a-Si:H films evolve hydrogen explosively during the high temperature crystallzation step. In result, the recrystallized polycrystalline silicon(poly-Si) films have poor surface morphology. In order to avoid the hydrogen evolution, the films have undergone the dehydrogenation step prior to the crystallization step Before the RTA process, the active area of thin film transistors (TFT's) was patterned. The prepatterning of the a-Si:H active islands may reduce thermal damage to the glass substrate during the recrystallization. The computer generated simulation shows the heat propagation from the a-Si:H islands into the glass substrate. We have fabricated the poly-Si TFT's on the silicon wafers. The maximun ON/OFF current ratio of the device was over $10^5$.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.47-53
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• 2000

Saemangeum coastal area is being constructed the 33km sea dike and 40,000ha reclamation area. The purpose of this study is to find the residual circulations in spring before and after the dike construction by a robust diagnostic and prognostic numerical model. Heat flux at the sea surface in May was adopted on the basis of the daily inflow of solar radiation at the earth surface, assuming an average atmospheric transmission and no clouds, as a function of latitude and time of year(George L.P.,J. E. William,1990). The discharge from the Geum, the Mankyung and the Dongjin rivers was adopted on the basis of experience formula of river flow in May(The M. of C.,Korea, 1993). Water temperature and salinity along the open boundaries are obtained from the results of field observations. The results of spring of the residual flow in the Saemangeum coastal area by a prognostic numerical model lead to the following conclusions: Water temperature in spring is the highest, salinity is the lowest and density is the lowest at the upper layer near the coast after the dike construction. The flow pattern at the upper layer during spring is anti-clockwise circulation between Wi and Shinsi islands. The flow pattern at the lower layer is clockwise circulation between Wi and Shinsi islands.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.77-80
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• 2024

Aedes albopictus, a common species in the Republic of Korea, is internationally known as a major vector for various diseases, and it is well-adapted to urban environments. Recent insect outbreaks in urban areas, attributed to climate change and urban heat islands, have increased the necessity of researching the effects on mosquito populations. This study analyzed climate data from 25 Automatic Weather System (AWS) stations in Seoul, identifying urban areas with pronounced heat island effects and suburban areas with milder effects. Nine urban heat island conditions were established based on this analysis, under which the hatching rates of Ae. albopictus were examined. The results revealed an increase in hatching rates correlating with the intensity of the urban heat island effect. Regression analysis further indicated that this trend accelerates as the strength of the heat island effect increases. This study suggests that temperature variations resulting from urban heat island phenomena can significantly influence the hatching rates of Ae. albopictus.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.23-28
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• 1999

This study measured transpiration rate of urban trees and albedos of urban surfaces, and examined the function of microclimate amelioration by urban greenspace. Transpiration rates of trees were highest in July and August of growing months. Transpiration per unit leaf area for the two months was 300-350 g/$m^2$/h for Platanus occidentalis, 210-270 g/$m^2$/h for Ginkgo biloba and Zelkova serrata, and 130-140 g/$m^2$/h for Acer palmatum. Surface albedos were 0.09 for asphalt paving and 0.68 for white wall, which reveals that light-colored surfaces are better than dark-colored ones to lower the heat build-up. Due to lack of evapotranspiration, concrete surfaces were, at t midafternoon maximum, 8$^{\circ}C$ hotter than grass ones, though the albedo of concrete paving was higher thant that of grass and trees. Summer air temperatures at places with 12% and 22% cover of woody plants were, respectively, 0.6$^{\circ}C$ and 1.4$^{\circ}C$ cooler than a place with no vegetation. To mitigate the impacts of urban heat islands, required are minimization of hard surfaces, light-coloring for building surfaces, and greenspace enlargement including more plantings.