• KIEAE Journal
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• 제16권6호
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• pp.95-101
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• 2016

Purpose: This study aims to identify the effect of temperature reduction by the application of cool roof coatings to Changwon City Hall in South Gyeongsang Province. The indoor and outdoor temperatures of the cool roofing building were analyzed and compared to that of an existing building with green-colored roof coated with waterproof polyurethane. Method: The surface temperatures and reflectivity of rooftops, surface temperatures of ceilings and the interior, and outdoor temperature and humidity of the two aforementioned buildings were measured from June to September in 2014. The measurements were taken every 10 min. Result: The surface temperature of the building with the cool roof was lower by a maximum of $9^{\circ}C$ with the reflectivity of the rooftop at an average of 0.55, which is higher than that of the building with green polyurethane by approximately 0.3. The temperature of the ceiling inside the building with the cool roof was about $1{\sim}2^{\circ}C$ lower than that of the ordinary building. Also, the indoor temperature of the office with cool roof coatings was about $0.5{\sim}1.0^{\circ}C$ lower than that of the office with green-colored roofing building. The results show that cool roof coatings can lower the temperature of buildings. In the next research, the reduction in consumption of energy for air conditioning will be investigated by utilizing building energy simulation tools.

• 한국농공학회논문집
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• 제49권1호
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• pp.79-88
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• 2007

We investigated the characteristics of temperature variations under different land covers (paddy field, upland, urban park, and urban residential area) during hot summer (July 15 to August 19, 2005). The temperatures were monitored using data loggers at one hour intervals in study sites. The mean temperature generally increased with the distance from edge of paddy fields, being $1.5^{\circ}C$ higher at a site 170-m far from paddy fields than at a paddy field area at 22 h. The mean daily temperatures in the study period followed the ordo. of paddy field $(26.6^{\circ}C)$ < upland $(27.0^{\circ}C)$ < park $(27.5^{\circ}C)$ < residential area $(28.0^{\circ}C)$. The paddy field area has shown remarkable cooling effects compared to the residential area: Mean duration of temperature below $25^{\circ}C$ in the paddy field area was longer (8.6 hrs) than in the residential area; The time to fall to below $25^{\circ}C$ in the paddy field area was sooner (22.4 hr) than in the residential area; Mean daily minimum temperature in the paddy field area was much lower $(2.4^{\circ}C)$ than in the residential area. More research is needed to better clarify the mechanism of cooling effect of a paddy field area by investigating heat balance of a paddy field.

• 한국측량학회지
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• 제39권2호
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• pp.113-122
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• 2021

Urban expansion, particularly converting sub-urban areas to residential and commercial land use in metropolitan areas, has been considered as a significant signal of regional economic development. However, this results in urban climate change. One of the key impacts of rapid urbanization on the environment is the effect of UHI (Urban Heat Island). Understanding the effects of urban land cover change on UHI is crucial for improving the ecology and sustainability of cities. This research reports an application of remote sensing data, GIS (Geographic Information Systems) for assessing effects of urban land cover change on the LST (Land Surface Temperature) and heat budget components in Ho Chi Minh City, where is one of the fastest urbanizing region of Vietnam. The change of urban land cover component and LST in the city was derived by using multi-temporal Landsat data for the period of 1998 - 2020. The analysis showed that, from 1998 to 2020 the city had been drastically urbanized into multiple directions, with the urban areas increasing from approximately 125.281 km² in 1998 to 162.6 km² in 2007, and 267.2 km² in 2020, respectively. The results of retrieved LST revealed the radiant temperature for 1998 ranging from 20.2℃ to 31.2℃, while that for 2020 remarkably higher ranging from 22.1℃ to 42.3℃. The results also revealed that given the same percentage of urban land cover components, vegetation area is more effective to reduce the value of LST, meanwhile the impervious surface is the most effective factor to increase the value of the LST.

• 한국농림기상학회지
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• 제4권1호
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• pp.58-63
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• 2002

1951-1980 평년기온 대비 1971-2000 평년기온 상승을 남한지역 14개 관측소 소재 시군의 1966년 대비 1990년의 인구증가 자연대수값에 회귀시켜 통계적으로 유의한 관계식을 얻었다. 이 관계식을 이용하여 도시화에 따른 승온효과를 제거할 경우, 순수한 지구 온난화 효과는 12월부터 4월 사이의 한후기에만 인정되며, 나머지 계절에는 나타나지 않았다. 남한지역의 한후기 일평균기온은 지구온난화에 의해 최대 0.6$^{\circ}C$까지 상승하였으며 일최저기온보다 일최고기온 상승폭이 컸다. 도시화에 따른 승온효과는 최대 0.3$^{\circ}C$에서 0.5$^{\circ}C$로 연 중(4월 제외) 고르게 나타났지만, 주로 일최저기온의 상승을 주도하였고 일최고기온 상승에는 거의 영향이 없었다.

• Natural Product Sciences
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• 제11권2호
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• pp.67-74
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• 2005

The ethanolic extracts of the leaves and bulbs of Allium victorialis var. platyphyllum (Liliaceae) collected from Daegwallyoung (D) and Ullung Island (U) in Korea were obtained using three different extracting methods. The first extracts, DL-1 DB-1, UL-1 and UB-1, were obtained from leaves (L) and bulbs (B) dried at $90^{\circ}C$, respectively, and the second extracts, DL-2, DB-2, UL-2 and UB-2, were obtained by extracting the leaves and bulbs of fresh plant parts. The third extracts DL-3, DB-3, UL-3 and UB-3 were obtained by incubating leaves and bulbs at $36^{\circ}C$. The six extracts obtained from A. victorialis var. platyphyllum at Daegwanllyoung (cultivated site) were orally administered to examine for a possible antihepatotoxic effect in $CCl_4-induced$ rats. DL-1 exhibited the most pronounced effect. The extracts inhibited serum ALT, AST, SDH, ${\gamma}-GT$, ALP and LDH activities elevated by $CCl_4$ injection and attenuated decreased glutathione S-transferase, glutatione reductase and ${\gamma}-glutamylcysteine$ synthetase activities and a decreased hepatic glutathione. However, the extracts obtained from Ullung Is. (native site) were less active than the extracts from Daegwallyoung, suggesting that A. victorialis var. platyphyllum from the cultivated site is more useful for functional food than of native site. These results also suggest that the antihepatotoxic effect is due to a higher content of hepatic glutathione. Gas chromatography of the twelve extracts showed significantly different sulfides, disulfides or trisulfides contents belonging to volatile sulfur substances (VSS). Nine components were identified on the basis of their mass spectra, namely, dimethyl disulfide, dimethyl trisulfide, diallyl disulfide, dipropyl disulfide, allyl methyl sulfide, allyl methyl trisulfide, 2-vinyl-4H-1,3-dithiin, 3,4-dihydro-3-vinyl-1,2-dithiin, and allithiamine. Extract DL-1 had the highest VSS content. Dried plant materials contained larger amounts of the VSSs than other extracts, and the leaves contained larger amount than the bulbs. These results suggest that heat treatment increases the antiheaptotoxic ability of A. victorialis var. platyphyllum by increasing the proportion of VSSs.

• 한국환경과학회지
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• 제22권11호
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• pp.1443-1449
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• 2013

This was an experimental study to evaluate temperature reduction and evapotranspiration of extensive green roof. Three test cells with a dimension of $1.2(W){\times}1.2(D){\times}1.0(H)$ meters were built using 4-inch concrete blocks. Ten-centimeter concrete slab was installed on top of each cell. The first cell was control cell with no green roof installed. The second and third cells were covered with medium-leaf type Zoysiagrass (Zoysia japonica) above a layer of soil. Soil thickness on the second cell was 10cm and that on the third cell was 20cm. Air temperature, relative humidity and solar irradiance were measured using AWS (automatic weather system). Temperature on top surface and ceiling of the control cell and temperature on top surface, below soil and ceiling of green roof cells was measured. Evapotranspiration of the green roof cells were measured using weight changes. Compared with temperature difference on the control cell, temperature difference was greater on green roof cells. Between two green roof cells, the temperature difference was greater on the third cell with a thicker soil layer. Temperature differences below soil and on ceilings of green roof cells were found greater than those of the control cell. Between the green roof cells, there was no difference in the temperature reduction effects below soil and on ceilings based on substrate depth. In summary, green roof was found effective in temperature reduction due to evapotranspiration and shading effect.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.104-108
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• 2009

Rapid urbanization resulted in expansion of urban area and increase of population bringing deepened housing shortage. Supply-oriented housing policy made apartment a representative residential space in Korea in spite of the short history of apartment. This study analyzed the shape and arrangement of main building by year and the microclimate in the complex depending on the number of floors. The purpose of this study was to present the basic data in developing apartment complex to solve problems like the stagnation of pollution source and the rise of temperature due to the declined ventilation in apartment complex, and the worsened urban heat island phenomenon due to the impeded flow of wind. This study rearranged the shape and arrangement of main building by year and the tendency of the number of floors by year in the process of change, by generalizing the process of change of apartment complex, a representative modern residential space through preliminary research. Based on it, 8 object lot by age was selected and simulated by using Envi-met. Simulation identified that the change of apartment complex takes place having a positive effect on microclimate in the apartment complex and the microclimate in the apartment complex is influenced a lot by the shape of complex. If in future apartment complex plan, a systematic legal criteria of design is made about the shape and arrangement of main building, it might have a positive effect on the improvement of microclimate in the apartment complex, a representative residential space in Korea.

• 한국습지학회지
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• 제21권spc호
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• pp.117-122
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• 2019

도시공원은 지구온난화와 대기오염을 줄여주고 열섬현상을 완화시켜주는 중추적인 역학을 하고 있다. 그러나 도시공원 일몰제에 따른 2020년 7월 이후 도시공원 제한이 일부 해제될 예정이다. 이에 따라 정부와 지자체는 공원부지 확보와 더불어 생태공원 조성 등 공원 활성화를 위한 노력을 기울이고 있다. 그러나 도시공원 주변에 건설되고 있는 고층건축물에 의해 발생하는 빌딩풍은 보행자에게 불쾌감을 유발할 수 있고, 생태공원에 서식하고 있는 동·식물의 생태계를 위협할 수 있다. 우리나라의 풍환경 평가에 대한 기준은 명확하게 제안된 바가 없으며, 관련 연구 또한 찾아보기 힘들다. 따라서 본 논문에서는 국외풍환경 평가기준 및 관련 연구를 검토하여, 풍환경 평가 기준의 중요 인자를 도출하고, 국내 기상관측자료를 이용한 풍환경 평가에 적용 가능성을 검토하였다.

• 한국환경과학회지
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• 제29권4호
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• pp.403-413
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• 2020

The purpose of this study is to understand the formation of internal wind paths of open space and its effect on meteorological factors and the generation of negative air ions. Various types of internal wind paths of open space were formed. Subsequently, changes in meteorological factors in each type were measured and the generated negative air ions were analyzed. The four key findings of the study are summarized as follows. First, the average wind speed formed inside the open space was analyzed such that the difference in wind speed was dependent on the difference in the composition of the wind path. Second, the negative air ion generation was observed to have the same trend as the average wind speed difference. Third, changes to the meteorological factors were more evident depending on the difference in wind path formation patterns. Solar radiation was expected to be highly affected by the physical structure (direction) of the target site. The relative humidity was found to show large difference depending on the different wind path type; however, this difference was significantly reduced when converting to absolute humidity. Fourth, it was found that the wind path formation type of open space affects meteorological factors through path analysis, and the changed meteorological factors affect the amount of generated negative air ions. Two conclusions can be obtained based on these results. First, the changes in internal wind speed formation of open space directly reduced the amount of generated negative air ions. Second, the changes in wind speed affect meteorological factors as well as the amount of generated negative air ions.

• KIEAE Journal
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• 제14권1호
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• pp.31-38
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• 2014

Recently, the coverage of urban forests has been rapidly decreasing as the cities are created and expanding. Consequently, there arise urban problems such as heat island effect, urban flooding, urban desertification and so on. In this context, green roof systems is considered to be an efficient alternative to deal with these problems. However, it is difficult to apply green roof to new buildings since the majority of the buildings in cities are already constructed and the demand for new building constructions is not high enough. Therefore, it should be considered to apply green roof system to existing buildings for resolving various problems. This study evaluates heating and cooling energy consumption based on the combination of passive design factors such as wall, roof, window insulation in addition to a green roof system applied to an existing house by using an energy simulation program. Total 8 potential improvement cases are developed. Each case is applied to the same house with different insulation standard for simulations. Through the analysis of the simulated cases with the chosen test house, it is confirmed that heating energy consumption decreases as improvement cases are applied, but cooling energy consumption is relatively not much affected by each improvement case. In addition, when each improvement case is applied to already highly insulated house, the effect of thermal energy improvement decreases while the same improvement that is applied to the case with low insulated house tends to yield higher improvement rate.