• Title/Summary/Keyword: heat island

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Surrogate Models and Genetic Algorithm Application to Approximate Optimization of Discrete Design for A60 Class Deck Penetration Piece (A60 급 갑판 관통 관의 이산설계 근사최적화를 위한 대리모델과 유전자 알고리즘 응용)

  • Park, Woo Chang;Song, Chang Yong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.2
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    • pp.377-386
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    • 2021
  • The A60 class deck penetration piece is a fire-resistant system installed on a horizontal compartment to prevent flame spreading and protect lives in fire accidents in ships and offshore plants. This study deals with approximate optimization using discrete variables for the fire resistance design of an A60 class deck penetration piece using different surrogate models and a genetic algorithm. Transient heat transfer analysis was performed to evaluate the fire resistance design of the A60 class deck penetration piece. For the approximate optimization of the piece, the length, diameter, material type, and insulation density were applied to discrete design variables, and temperature, productivity, and cost constraints were considered. The approximate optimum design problem based on the surrogate models was formulated such that the discrete design variables were determined by minimizing the weight of the piece subjected to the constraints. The surrogate models used in the approximate optimization were the response surface model, Kriging model, and radial basis function-based neural network. The approximate optimization results were compared with the actual analysis results in terms of approximate accuracy. The radial basis function-based neural network showed the most accurate optimum design results for the fire resistance design of the A60 class deck penetration piece.

Prediction of Land Surface Temperature by Land Cover Type in Urban Area (도시지역에서 토지피복 유형별 지표면 온도 예측 분석)

  • Kim, Geunhan
    • Korean Journal of Remote Sensing
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    • v.37 no.6_3
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    • pp.1975-1984
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    • 2021
  • Urban expansion results in raising the temperature in the city, which can cause social, economic and physical damage. In order to prevent the urban heat island and reduce the urban land surface temperature, it is important to quantify the cooling effect of the features of the urban space. Therefore, in order to understand the relationship between each object of land cover and the land surface temperature in Seoul, the land cover map was classified into 6 classes. And the correlation and multiple regression analysis between land surface temperature and the area of objects, perimeter/area, and normalized difference vegetation index was analyzed. As a result of the analysis, the normalized difference vegetation index showed a high correlation with the land surface temperature. Also, in multiple regression analysis, the normalized difference vegetation index exerted a higher influence on the land surface temperature prediction than other coefficients. However, the explanatory power of the derived models as a result of multiple regression analysis was low. In the future, if continuous monitoring is performed using high-resolution MIR Image from KOMPSAT-3A, it will be possible to improve the explanatory power of the model. By utilizing the relationship between such various land cover types considering vegetation vitality of green areas with that of land surface temperature within urban spaces for urban planning, it is expected to contribute in reducing the land surface temperature in urban spaces.

Analysis of Environmental Equity of Green Space Services in Seoul - The Case of Jung-gu, Seongdong-gu and Dongdaemun-gu - (서울지역 녹지서비스의 환경형평성 분석 - 중구, 성동구, 동대문구를 사례로 -)

  • Ko, Young Joo;Cho, Ki-Hwan;Kim, Woo-Chan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.2
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    • pp.100-116
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    • 2019
  • Urban green spaces, as a means to mitigate social problems and environmental risks, are getting more attention in evaluating urban environment. The inequity of green space distribution is becoming a major issue in urban planning and management. This study investigated the characteristics of green space in 3 districts (Jung-gu, Dongdaemun-gu, Seongdong-gu), that are composed of 46 administrative divisions in central Seoul, to analyze the environmental equity of urban green spaces. The correlations between the amount of green space, including the coverage of street trees, and the socioeconomic status of each administrative division were analyzed. To deduce the effects of plant coverage on the urban temperature regime, the relationship between the normalized difference of vegetation index (NDVI) and land surface temperature (LST) was analyzed. The research revealed that the mean NDVI of an administrative division was negatively correlated with the percentage of basic living recipients and disabled people. The LST of a division with low NDVI was higher due to the lack of green coverage. Such environmental inequities were closely related to residential building type, which was strongly affected by the economic status of residents. The LST of an apartment area was $2.0^{\circ}C$ lower than that of single-family houses and multi-housing areas. This is expected as the average NDVI of the apartment area was more than twice as high as the other environments considered in this study. The inequity can be exacerbated without urban planning which is deliberately designed to reduce it.

Performance evaluation of Surface Temperature Reduction by using Green infrastructure Surface Temperature Measurement for Urban Heat Island Mitigation (도시열섬완화를 위한 그린인프라시설의 표면온도 저감 성능평가)

  • Ko, Jong Hwan;Bae, Woo Bin;Park, Dae Geun;Jung, Won Kyong;Park, Yun mi;Kim, Yong Gil;Kim, Sang Rae
    • Ecology and Resilient Infrastructure
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    • v.5 no.4
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    • pp.257-263
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    • 2018
  • This study is to develop a GSTM (Green infrastructure Surface Temperature Measurment) equipment for reducing the surface temperature of GI by using LID Method. The tests were conducted including GI products such as Greening block, Pervious Block, Soil Block and so on. The GSTM equipment developed by considering the literature surveys are characterized as follows. The non-contact infrared temperature sensor was used to measure the surface temperature, and it was improved to measure the overall average temperature including the center and the corner temperature of the specimen. The developed GSTM equipment was used to compare performance of asphalt and GI products. As a result, the Greening Block show a high difference of $18.4^{\circ}C$ and it contributes to the decrease of surface temperature.

Distribution Analysis of Land Surface Temperature about Seoul Using Landsat 8 Satellite Images and AWS Data (Landsat 8 위성영상과 AWS 데이터를 이용한 서울특별시의 지표면 온도 분포 분석)

  • Lee, Jong-Sin;Oh, Myoung-Kwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.434-439
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    • 2019
  • Recently, interest in urban temperature change and ground surface temperature change has been increasing due to weather phenomenon due to global warming, heat island phenomenon caused by urbanization in urban areas. In Korea, weather data such as temperature and precipitation have been collected since 1904. In recent years, there are 96 ASOS stations and 494 AWS weather observation stations. However, in the case of terrestrial networks, terrestrial meteorological data except measurement points are predicted through interpolation because they provide point data for each installation point. In this study, to improve the resolution of ground surface temperature measurement, the surface temperature using satellite image was calculated and its applicability was analyzed. For this purpose, the satellite images of Landsat 8 OLI TIRS were obtained for Seoul Metropolitan City by seasons and transformed to surface temperature by applying NASA equation to the thermal bands. The ground measurement data was based on the temperature data measured by AWS. Since the AWS temperature data is station based point data, interpolation is performed by Kriging interpolation method for comparison with Landsat image. As a result of comparing the satellite image base surface temperature with the AWS temperature data, the temperature difference according to the season was calculated as fall, winter, summer, based on the RMSE value, Spring, in order of applicability of Landsat satellite image. The use of that attribute and AWS support starts at $2.11^{\circ}C$ and RMSE ${\pm}3.84^{\circ}C$, which reflects information from the extended NASA.

A Study on the Effectiveness of Wind Corridor Construction forImproving Urban Thermal Environment: A Case study of Changwon, South Korea (도시 열환경 개선을 위한 취약지역 선정 및 바람길 조성 방안: 창원시를 대상으로)

  • Kim, Jong-Sung;Kang, Jung-Eun
    • Journal of Environmental Impact Assessment
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    • v.30 no.4
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    • pp.187-202
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    • 2021
  • This study examined the effectiveness of wind corridor construction by analyzing the thermal environment, cold air generation, ventilation, and geographical characteristics to improve urban thermal environment and establish the basis for specialized strategy in Changwon-si, Gyeongsangnam-do. Using spatial analysis and remote sensing techniques, surface temperature, land cover and land use, wind field, and slope were measured and through this, a wind corridor analysis model was constructed. As a result of the analysis as of 2020, Changwon-si generally has land cover characteristics that are advantageous for the generation of cold air, but the temperature in most urban areas is the highest, and the temperature in areas such as north Changwon area, Jinbukmyeon, Ung-dong, and Ungcheon-dong are relatively high. There was a typical trend of high average wind speed in mountain regions and low average wind speed in urban areas. Accordingly, the north Changwon area, the former Changwon downtown area, the Hogye-ri and Pyeongseong-ri areas, and the Changpo Bay area are derived as vulnerable areas to thermal environment, and various measures to reduce temperature and improve air quality that the inflow of cold air into the area considering the characteristics of each area and securing wind ventilation between the surrounding mountains, reservoirs, and park areas were proposed.

Complementary measures for Environmental Performance Evaluation Index of External Space of Green Standard for Energy and Environmental Design for Apartment Complex - Focused on the Respect of Response to Climate Change - (공동주택 녹색건축인증기준의 외부공간 환경성능 평가지표 보완방안 - 기후변화 대응 측면을 중심으로 -)

  • Ye, Tae-Gon;Kim, Kwang-Hyun;Kwon, Young-Sang
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.1
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    • pp.3-14
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    • 2018
  • An apartment complex is a building use with great potential to contribute to solving problems related to urban ecological environment and climate change. The first goal of this study is to grasp the current situation of application and limitations of the ecological area rate, which is a representative evaluation index used to evaluate the environmental performance of the external space of an apartment complex in Green Standard for Energy and Environmental Design (G-SEED). The second goal is to propose a prototype of the evaluation index for evaluating greenhouse gas (GHG) reduction performance in order to supplement the evaluation index for the environmental performance of the external space in terms of response to climate change. We analyzed 43 cases of apartment complexes certified according to G-SEED, which was enforced since July 1, 2010, and found application characteristics of each space type and the limitations of ecological area rate. We analyzed overseas green building certification systems such as LEED and BREEAM that derived implications for supplementing the limitations of ecological area rate, which is focused on the evaluation of soil and water circulation function, and set up a development direction of complementary measures. Through analysis of previous studies, relevant regulations and standards, and technical documents of the manufacturer, the heat island mitigation performance of the pavement and roof surfaces of the apartment complex and the carbon uptake performance of the trees in the apartment complex was selected as parameters to yield the GHG reduction performance of the external space of the apartment complex. Finally, a quantitative evaluation method for each parameter and a prototype of the evaluation index for the GHG reduction performance were proposed. As a result of applying the prototype to an apartment complex case, the possibility of adoption and applicability as an evaluation index of G-SEED were proved.

A Study on the Necessity of Vertical Garden in Public Places for Urban Environment Improvement (도시환경 개선을 위한 공공장소의 수직정원 필요성에 관한 연구)

  • Kim, Chul-soo
    • Journal of the Korea Convergence Society
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    • v.12 no.6
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    • pp.75-81
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    • 2021
  • (Research background and purpose) Urban development has also had a significant impact on the eco-friendly industry. In the public environment, citizens are stressed in many areas, which has really made them need a natural ecological environment. Therefore, it is necessary to improve the environment into an eco-friendly urban public facility that breathes the urban environment space inside the building with plants. To this end, we want to show that the urban environment can be improved through vertical gardens. And through this, we want to contribute to the popularization of vertical gardens. (Research Methodology) we will analyze the problems of the current public environment in the city and look at the supplementation around vertical gardens. (Result) A study of the public environment in the city found problems such as gloomy environment, poor use of space, dim color, and poor air quality, and wanted to create a vertical garden to provide a pleasant shelter. These vertical gardens have influenced urban public places with improved aesthetics, increased social value, insulation and soundproofing effects of buildings, reduced urban heat island effects, and increased urban green appearance. (Conclusion)This study uses vertical gardens in public spaces to design public spaces that are more comfortable and share mental and physical health together.

A field Study to Evaluate Cooling Effects of Green Facade under Different Irrigation Conditions - Focusing on modular green facade planted with Hedera helix L and Pachysandra terminalis - (관수조절에 의한 벽면녹화의 냉각효과 분석 연구- 아이비, 수호초를 식재한 모듈형 벽면녹화를 중심으로-)

  • Kim, Eun-Sub;Yun, Seok-Hwan;Piao, Zheng-gang;Jeon, Yoon-Ho;Kang, Hye-Won;Kim, Sang-Hyuck;Kim, Ji-Yeon;Lee, Young-Gu;Lee, Dong-Kun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.24 no.6
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    • pp.121-132
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    • 2021
  • Green facade has a significant impact on building's energy performance by controlling the absorption of solar radiation and improving outdoor thermal comfort through shading and evapotranspiration. In particular, since high-density building does not enough green space, green facade, and rooftop greening using artificial ground plants are highly utilized. However, the level of cooling effect according to plant traits and irrigation control is different. Therefore, in this study, the cooling effect analyzed for a total of 4 cases by controlling the irrigation condition based on hedera and spurge. Although hedera under sufficient water had the highest cooling effect(-2℃~-4℃), had the lowest cooling effect under non-irrigation(+1.1℃~+4.4℃). In addition, hedera under sufficient water had cooling effect than hedera under non-irrigation(-1℃~-8.1℃) and in the case of spurge, it had cooling effect(-0.3℃~-7.8℃) more than non-irrigation. As a result of measuring the amount of transpiration according to the light intensity (PAR) and carbon dioxide concentration conditions, transpiration of hedera was higher than the spurge (respectively 0.63204mmolm-2s-1, 0.674367mmolm-2s-1). The difference in the cooling effect of the green facade under irrigation condition was significant. But the potential cooling effect of green facade according to plants species was different. Therefore, in order to maximize and continuously provide the cooling effect of green facade in urban areas, it is necessary to consider the characteristics of plants and the control of water supply through the irrigation system.

Ventilation Corridor Characteristics Analysis and Management Strategy to Improve Urban Thermal Environment - A Case Study of the Busan, South Korea - (도시 열환경 개선을 위한 바람길 특성 분석 및 관리 전략 - 부산광역시를 사례로 -)

  • Moon, Ho-Yeong;Kim, Dong-Pil;Gweon, Young-Dal;Park, Hyun-Bin
    • Korean Journal of Environment and Ecology
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    • v.35 no.6
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    • pp.659-668
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    • 2021
  • The purpose of this study is to propose a ventilation corridor management plan to improve the thermal environment for Busan Metropolitan City. To this end, the characteristics of hot and cool spots in Busan were identified by conducting spatial statistical analysis, and thermal image data from Landsat-7 satellites and major ventilation corridors were analyzed through WRF meteorological simulation. The results showed the areas requiring thermal environment improvement among hot spot areas were Busanjin-gu, Dongnae-gu, industrial areas in Yeonje-gu and Sasang-gu, and Busan Port piers in large-scale facilities. The main ventilation corridor was identified as Geumjeongsan Mountain-Baekyangsan Mountain-Gudeoksan Mountain Valley. Based on the results, the ventilation corridor management strategy is suggested as follows. Industrial facilities and the Busan Port area are factors that increase the air temperature and worsen the thermal environment of the surrounding area. Therefore, urban and architectural plans are required to reduce the facility's temperature and consider the ventilation corridor. Areas requiring ventilation corridor management were Mandeok-dong and Sajik-dong, and they should be managed to prevent further damage to the forests. Since large-scale, high-rise apartment complexes in areas adjacent to forests interfere with the flow of cold and fresh air generated by forests, the construction of high-rise apartment complexes near Geumjeongsan Mountain with the new redevelopment of Type 3 general residential area should be avoided. It is expected that the results of this study can be used as basic data for urban planning and environmental planning in response to climate change in Busan Metropolitan City.