• KIEAE Journal
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• 제16권6호
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• pp.69-75
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• 2016

Climate change has resulted in the urban heat island (UHI) effect throughout the globe, contributing to heat-related illness and fatalities. In order to reduce such damage, it is necessary to improve the climate observation network for precise observation of the urban thermal environment and quick UHI forecasting system. Purpose: This study analyzed the effective range of the climate observation network and the distribution of the existing Automatic Weather Stations (AWS) in Seoul to propose optimal locations for additional installment of AWS. Method: First, we performed quality analysis to pinpoint missing values and outliers within the high-density temperature data measured. With the result from the analysis, a spatial autocorrelation structure in the temperature data was tested to draw the effective range and correlation distance for each major time period. Result: As a result, it turned out that the optimal effective range for the climate observation network in Seoul in July was a radius of 2.8 kilometers. Based on this result, population density, and temperature data, we selected the locations for additional installment of AWS. This study is expected to be used to generate urban temperature maps, select and move measurement locations since it is able to suggest valid, specific spatial ranges when the data measured in point is converted into surface data.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.81-87
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• 2009

The purpose of this study is to evaluate of the outdoor thermal environment by building scale and block type as variable factors. In this study, 18 cases of office in central business district that have different condition are compared about their surface temperature, HIP(Heat Island Potential), and MRT(Mean Radiant Temperature). They are simulated with 3-dimension numerical simulation software named Hoyano-model. The output results contain visualized distribution chart and numerical data. The results of evaluation are as follows. (1)The surface temperature of the building becomes higher as building coverage ratio is higher but floor area ratio is lower. In same conditions, unified block type is maximum $3.2^{\circ}C$ higher than divided block type. (2)HIP shows different daily pattern as block type. During daytime, divided block type is much higher than unified block type but after sunset, it is changed. (3)MRT shows different distribution pattern as sunlight moves expecially at noon. (4)As the results of this study, cases that have high floor area ratio condition show lower surface temperature by tendency to stay low indoor temperature in office building and big rate of windows on building surface.

• 한국태양에너지학회 논문집
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• 제30권3호
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• pp.71-80
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• 2010

This study carried out to understand the thermal characteristics of various surface material which compose the city through the observation in the summer. To examine passive cooling effect of planting of building, it is arranged four different materials that is natural grass, grass block, concrete slab and artificial grass. The results of this study are as follows; (1) Natural grass and grass block show the lower surface temperature because of the structures of leaf can do more thermal dissipation effectively. (2) There is little surface temperature between artificial grass and concrete. But there is little high surface temperature difference between natural grass and concrete because of latent heat effect. (3) The concrete can play a role of the tropical nights phenomenon as high heat capacity of concrete compare with other materials. (4) It is nearly same color in artificial grass and natural grass but there is large difference between natural grass and artificial grass at albedo. There is different albedo in near infrared ray range. (5) A short wave radiation gives more effect at the globe temperature than long wave radiation. (6) The artificial turf protected the slab surface temperature increase in spite of thin and low albedo materials.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.41-41
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• 2009

We utilized atomic layer deposition (ALD) for the growth of the ZnO channel layers in the oxide thin-film-transistors (TFTs) with a bottom-gate structure using a $SiO_2/p-Si$ substrate. For fundamental study, the effect of the channel thickness and thermal treatment on the TFT performance was investigated. The growth modes for the ALD grown ZnO layer changed from island growth to layer-by-layer growth at thicknesses of > 7.5 nm with highly resistive properties. A channel thickness of 17 nm resulted in the good TFT behavior with an onloff current ratio of > $10^6$ and a field effect mobility of 2.9 without the need for thermal annealing. However, further increases in the channel thickness resulted in a deterioration of the TFT performance or no saturation. The ALD grown ZnO layers showed reduced electrical resistivity and carrier density after thermal treatment in oxygen.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 추계종합학술대회
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• pp.614-617
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• 2000

영광 원자력발전소 온배수의 최대영향범위를 Lagrange 방법으로 파악하기 위하여 대조기에 TGPS Buoy의 궤적 및 이에 따른 표층수온의 측정을 년 4회 실시하였다. TGPS Bouy의 추적결과, 온배수는 낙조시 남서.서남서방향으로 플릅의 형태로 배수구로부터 약 12km 정도를 이동하며, 낙조류가 우세한 이 해역의 특성으로 3-4회에 걸친 거듭된 낙조류에 따라 칠산도까지 도달할 수 있었다. 그리고 온배수는 배수구로부터 춘.추계에 약 5km, 하계는 약 10km 떨어진 지점에서 수온급강하가 나타나고, 동계에는 차가운 대기에 의하여 지속적인 Cooling이 발생하는 것으로 나타났다.

• 한국환경복원기술학회지
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• 제12권2호
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• pp.83-94
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• 2009

Environmental pollution becomes a serious problem in urban areas. Moreover, densely constructed strictures can be problematic to cities due to the rising temperature they cause as well as the increasing accumulation of air pollutants they generate by interrupting airflow. In order to improve residential amenity, it is necessary to improve the thermal environment by preserving wind corridors. To do so requires consideration to important aspects such as building arrangement, scale, vegetation, and land cover, which all have an effect on wind corridors. In this study, a typical arrangement-complex, which is the primary form of housing in Korea, was selected as a case ENVI-met. As a result of empirical analysis, the optimal apartment-complex arrangement that is most suitable for mitigating urban heat-islands phenomenon was determined, The outcome of this study can be utilized as a planning technique for apartment-complex construction in consideration to type of buildings, scale of buildings, and land cover.

• 한국농공학회논문집
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• 제48권5호
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• pp.39-48
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• 2006

The objective of this research was to find an indirect method to estimate land surface temperature (LST) efficiently, using Landsat images. Agricultural fields including paddy fields have long been known to have multi-functions beneficial to the environment and ecology of the urban surrounding areas. Among these functions, the ambient temperature cooling (ATC) effect is widely acknowledged. However, quantitative and regional assessment of such effect has not been performed. Thermal remote sensing has been used over urban areas to assess the ATC effect, Thermal Island Effect(TIE), and as input for models of urban surface atmosphere exchange. Here, we review the use of thermal remote sensing in the study of paddy fields and urban climates, focusing primarily on the ATC effect. Landsat satellite images were used to determine the surface temperatures of different land cover types of a $44km^{2}$ study area in Cheongiu, Korea. The results show that the ATC is a function of paddy area percentage in Landsat pixels. Landsat pixels with higher paddy area percentage have much more cooling effect. The use of satellite data may contribute to a globally consistent method for analysis of ATC effect.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.137-146
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• 2007

This study is about the passive cooling effects of three outdoor solar shading facilities as trees, pergola with wistaria vine and membrane shading structure, which are expected to provide cool spots in the summer. Field observations of measuring thermal environment of selected facilities is executed. Thermal environment measuring was categorized as short wave radiation, long wave radiation, net radiation, globe temperature, surface temperature measured by infrared camera. Heat transfer mechanism is analyzed with overall data from field measurement. Results from this study are as below; 1) Radiation balance measured on shaded surface under membrane shading structure was 17%($86W/m^2$) of the unshaded surface radiation balance($511W/m^2$). 2) Surface temperature comparison between vegetation and membrane of the shading structure is performed at 3 o'clock in the afternoon. Surface temperature of vegetation was same as air temperature and that of membrane was $5^{\circ}C$ higher than air temperature. Vegetation transpiration is considered as the causing factor which make those differences. 3) Results from this study could be used as fundamental data for reducing heat island phenomena and continuos research on this subject would be needed.

• 한국주거학회논문집
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• 제22권3호
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• pp.93-100
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• 2011

The objective of this study is to provide basic objective data which can be utilized as an adjustment criterion for the alleviation of the limit on the number of floors of buildings by quantitatively evaluates the effect of the alleviation of the limit on the number of floors of buildings in apartment complexes on thermal environment of apartment complexes using data obtained from apartments in a class 2 general residential area. In this study, we carried out a thermal environment analysis utilizing the simulation of a virtual object area. The result is summarized as follows: The result of analyzing the entire surface temperature showed an equal decrease of surface temperature due to shadow in all scenarios and high floors showed a tendency of low surface temperature during daytime as the rate of shadow the high floors increase. This influences not only the surface temperature but also HIP and is judged to greatly contribute to the alleviation of the heat island effect. Also, the reason why HIP at high floors shows high values before sunrise and after sunset is thought to be because the concrete wall of the building maintains a high temperature during nighttime by absorbing and storing sunlight during daytime instead of reflecting it since it has low reflectance.

• 한국주거학회논문집
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• 제23권1호
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• pp.19-26
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• 2012

This study examines how fence demolition may change the thermal environments of external spaces of houses and suggests what factors need to be considered when a fence is demolished. The results of the research are summarized as follows. In terms of the surface temperature, there was no significant difference in all time plots after the removal of all materials. However, applying greening methods (changing the surface materials, planting trees, and building a green roof following fence demolition) could lower the surface temperatures, calling for proper plans for various greening methods. The MRT results indicates that walls block solar radiation and provide shade, reducing radiant heat from roads and surrounding structures during the daytime when solar radiation directly effects surface temperatures. Also, the application of greening methods such as planting vegetation and trees could have shading and evapotranspiration effects, leading to a lower temperature distribution. The HIP results were similar to the MRT results. They indicated that walls block solar radiation within the residential sections and provide shade, resulting in a lower temperature distribution during the daytime. However, areas where greening methods such as a green roof or tree planting were applied showed $1{\sim}2^{\circ}C$ difference in temperature distribution.