• Water for future
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• v.54 no.12
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• pp.22-28
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• 2021

• KIEAE Journal
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• v.10 no.4
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• pp.67-73
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• 2010

As more and more people desire to live in an apartment complex with a comfortable outdoor space, many construction company became interested in outdoor design. In order to increase the use of outdoor space and create the most pleasant environment, outdoor thermal environment and comfort should be evaluated quantitatively from the design stage. This study utilized ENVI-met 3.1 model to analyze outdoor thermal environment in apartment complex, and evaluated outdoor thermal comfort in 6 points of apartment complex. The physiologically equivalent temperature(PET) was employed as a outdoor thermal index. Playground B had a poor thermal environment with the maximum PET $43^{\circ}C$ (Very hot). Because shading by building and tree didn't affect outdoor thermal environment of playground B. To design comfortable outdoor space from the view point of thermal environment, the factors influencing Mean radiant temperature(MRT) and wind speed should be considered in design stage. Since it is difficult to control outdoor thermal environment compared with indoor environment, we should take into account an assessment for outdoor thermal environment and comfort in outdoor design stage.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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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.

• Atmosphere
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• v.16 no.3
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• pp.169-185
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• 2006

We have investigated the wind speed variations over the leeward region when the strong wind blows. In this study we employ Envi-met numerical model to simulate the effect of surface boundary conditions. This model is applied for three cases which are characterized by land use and terrain height. The base case having natural geographical condition shows the weakest wind speed around lee side of Chunsudae. The others which remove the vegetation and cut off the terrain above 20 m ASL represent the stronger wind speed than base case. The main factor of this result is the surface friction. The distinct variation of wind is found at offshore area between Chunsudae and the southern part of village, but the northern part where is apart from Chunsudae shows a small variation of wind pattern. The weakening of wind speed around residential area is a maximum of 4~10 m/s when the wind blows in the village as strong as 55 m/s. The gust wind speed is weakened about 7~17 m/s in this case if the coefficient of gust wind adapted as 1.75.

• Journal of Environmental Impact Assessment
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• v.20 no.2
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• pp.133-140
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• 2011

A numerical study with Envi-met model is experimented to investigate the characteristics of wind pattern in Gangwon innovation city. In all case, most conditions such as wind speed, temperature, and surface are considered as the same, but wind direction is the only different factor. The wind directions considered in this study have a meaning of prevailing wind direction. When the prevailing wind with the direction of $247^{\circ}$ blows into the city, the ventilation passage toward the outside of city is formed and the stagnation of air is not expressed. In case of having the direction of $270^{\circ}$, most evident ventilation passages are composed. When the inflow wind direction is the north, $0^{\circ}$, there is some possibility of stagnation phenomenon. The case where the representative wind direction of three kind will flow with development, in compliance with the building is caused by with screening effect of some and shows a true stagnation phenomenon, wishes in the park and flowing water and the greens area to be for a long time formed and the wind direction is maintained.

• Journal of Environmental Science International
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• v.30 no.1
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• pp.19-28
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• 2021

To reduce pollution, decrease the production of carbon dioxide, and to maintain a secure supply of energy, interest continues to grow in the area of renewable energy especially since there is a finite supply of cheap oil. Wind energy is one of the most viable options to consider and supply part of the energy needed to reduce dependence on foreign oil. However, it is difficult to predict the wind speed in an environment with many obstacles such as buildings and trees and getting accurate dimensions of those obstacles is difficult particularly on sloped mountainous terrain. In this study a drone was used to create a 3-D map of the campus of the Catholic University of Pusan. The dimensions and elevations for the 3-D map were used to make a model of the school campus in the CFD program Envi-met. Simulations were run for five different wind directions and 4 different elevations to find the location that would give the highest electrical output for a wind turbine. When considering all of these variables it was found that the optimal location was above the Student Union which had a 40% higher wind speed and could produce 274% more electrical power than the original wind speed.

• Journal of Environmental Science International
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• v.29 no.12
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• pp.1153-1170
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• 2020

With global warming and the rapid increase in urbanization accompanied by a concentration of population, the urban heat island effects (UHI) have become an important environmental issue. In this study, rooftop greening and permeable asphalt pavement were selected as measures to reduce urban heat island and applied to a simple virtual urban environment to simulate temperature change using ENVI-met. A total of five measures were tested by dividing the partial and whole area application of each measure. The results showed that the temperature range of the base experiment is 33.11-37.11 ℃, with the UTCI comfort level described as strong heat and very strong heat stress. A case applied permeable asphalt has a greater temperature difference than a rooftop greening case, the larger the area where each condition was applied, the greater the temperature change was.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.95-98
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• 2010

OpenFlow 는 인터넷 스위치(라우터 포함)를 부분적으로 개선하여 연구자가 기존 네트워크의 정상적인 서비스를 간섭하지 않으면서 새로운 네트워킹 기술을 테스트할 수 있는 미래인터넷 (Future Internet) 연구를 위한 프로토콜이다. 하지만 OpenFlow 기반 테스트베드의 상태 정보를 확인하고 발생한 플로우들을 제어할 수 있는 도구(tool)가 부족하여, 연구자가 실험의 다양성을 제공 받기 어렵다. ENVI(Extensible Network Visualization & Control Framework)는 OpenFlow 네트워크 가시화를 위한 프레임워크로, 사용자의 목적에 맞는 인터페이스를 만들도록 제공해 준다. 본 논문에서는 OpenFlow 기반 테스트베드의 토폴로지 정보 및 플로우 상태를 쉽게 확인하고, 플로우 경로를 제어하는 OpenFlow 제어기 응용의 개발과 ENVI 의 확장을 설계하고 이를 구현을 통해 검증한다.

• Journal of the Korean earth science society
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• v.41 no.2
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• pp.111-128
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• 2020

This study presents a possibility of intensification of fine dust mass concentration due to the complex urban structure using data mining technique and clustering analysis. The data mining technique showed no significant correlation between fine dust concentration and regional-use public urban data over Seoul. However, clustering analysis based on nationwide-use public data showed that building heights (floors) have a strong correlation particularly with PM₁₀. The modeling analyses using the single canopy model and the micro-atmospheric modeling program (ENVI-Met. 4) conducted that the controlled atmospheric convection in urban area leaded to the congested flow pattern depending on the building along the distribution and height. The complex structure of urban building controls convective activity resulted in stagnation condition and fine dust increase near the surface. Consequently, the residual effect through the changes in the thermal environment caused by the shape and structure of the urban buildings must be considered in the fine dust distribution. It is notable that the atmospheric congestion may be misidentified as an important implications for providing information about the residual probability of fine dust mass concentration in the complex urban area.

• Journal of Environmental Impact Assessment
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• v.28 no.1
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• pp.23-34
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• 2019

Global warming becomes a serious issue that poses subsidiary issues like a sea level rise or a capricious climate over the world. Because of severe heat-wave of the summer in Korea in 2016, a big attention has been focused on urban heat island since then. Not just about heat-wave itself, many researches have been concentrated on how to adapt in this trendy warming climate and weather in a small scope. A big part of existing studies is mitigating "Urban Heat Island effect" and that is because of huge impervious surface in urban area where highly populated areas do diverse activities. It is a serious problem that this thermal context has a high possibility causing mortality by heat vulnerability. However, there have been many articles of a green infrastructures' cooling impact in summer. This research pays attention to measure cooling effect of a street planting considering urban canyon and type of green infrastructures in neighborhood scale. This quantitative approach was proceeded by ENVI-met simulation with a spatial scope of a commercial block in Seoul, Korea. We found the dense double-row planting is more sensitive to change in temperature than that of the single-row. Among the double-row planting scenarios, shrubs which have narrow space between the plant and the land surface were found to store heat inside during the daytime and prevent emitting heat so as to have a higher temperature at night. The quantifying an amount of vegetated spaces' cooling effect research is expected to contribute to a study of the cost and benefit for the planting scenarios' assessment in the future.