• Conservation Science in Museum
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• v.23
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• pp.71-90
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• 2020

The scientific analysis of a 'F-51D Mustang Fighter'(Registered Cultural Heritage 666), one of the War Memorial of Korean collections, was carried out. The paint layer and canopy were discolored due to a constant outdoor exhibit. The results obtained through the scientific survey and analysis processes were intended to be used as basic data for the future dismantling and restoration of the fighter. The analysis results for the pigment components have confirmed red oxide of iron, Fe₂O₃ organic pigments, such as Cobalt Blue, phthalocyanine blue, etc., yellow PbCrO₄, white TiO₂, black Fe₃O₄, and gray Fe₃O₄ + TiO₂. It has been also confirmed that Alkyd resin was mainly used for painting. The fighter's canopy was Poly methyl methacrylate(PMMA), and Al was detected as the main component of the fighter body, wings, and tails.

• Journal of the Korean Solar Energy Society
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• v.32 no.spc3
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• pp.185-193
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• 2012

Recently rapid urbanization facilitates development of high-rise building complex including apartment and office building in urban area. Many problems related with high -rise building are reported. Especially, unpleasant strong winds in pedestrian area are frequently encountered around the high-rise building. CFD simulation methods are used to analyze the wind environment of pedestrian level in high-rise building block. However, the results show differences between CFD and measurement. This difference is attributed to improper use of CFD. Conventional CFD simulation for wind environment around high-rise building does not describe the effect of trees, shrubs and plants near ground which affect the wind environment of pedestrian level. Canopy model can be used to reproduce the aerodynamic effects of trees, shrubs and plants near ground. In this paper, CFD simulation methods coupled with the tree canopy model to predict wind environment of pedestrian level in high-rise residential building block were suggested and the validity was analyzed by comparison between measurement and CFD results.

• Journal of Wetlands Research
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• v.10 no.1
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• pp.21-30
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• 2008

Evapotranspiration is an important factor in the energy interaction process between the surface and the air. Over a vegetable canopy, evapotranspiration was investigated by measuring the sensible heat flux, the soil heat flux and the net radiation flux. Evapotranspiration based on routine AWS data is in good agreement with that estimated from the energy balance equation except for weak wind shear less than $1s^{-1}$ and a cloudy period. Soil heat flux can be approximately to 10% of net radiation flux at the lower layer. When the slope of the saturation vapor pressure versus temperature curve ($de_s/dT$) is approximated to 1.5, the evapotranspiration can be described in function of the net radiation energy flux over Goheung bay wetland covered with the vegetable canopy, reeds.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.180-183
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• 2009

In this study, Urban Climate Simulation was performed by 3-Dimensional Urban Canopy Model. The characteristics of urban climate was analyzed combining artificial land coverage, building size, heat production from the air conditioning and topographic conditions as physical variables which affects urban climate characteristics. The results are as follows. (1)The aspects of the urban climatal change is derived to be related to the combination of the building coverage ratio, building height and shading area. (2)Whole heat generation was influenced by the convective sensible heat at the lower building height and by the artificial heat generation at the higher one over 20-story building influence to some extent of the building coverage ratio. The effect of the altitude is not more considerable than the other variables as below $1^{\circ}C$ of the air temperature.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.345-353
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• 2012

Recently rapid urbanization facilitates development of high-rise building complex including apartment and office building in urban area. Many problems related with high-rise building are reported. Especially, unpleasant strong winds in pedestrian area are frequently encountered around the high-rise building. CFD simulation methods are used to analyze the wind environment of pedestrian level in high-rise building block. However the results show differences between CFD and measurement. The reason for the difference is that conventional CFD simulation couldn't consider the effect of trees, shrubs and plants which affect the wind environment. Canopy model is a solution to solve the limitation of CFD analysis. In this paper, the canopy model to predict wind environment of pedestrian level by CFD simulation will be proposed and the validity will be analyzed by comparison of measurement and CFD prediction.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.12
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• pp.1045-1050
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• 2014

A Head-Up-Display is an avionic equipment to identify targets and flight data at same time the pilot looks over the external environment outside canopy. The HUD displays various symbols to depend on avionic mode which is composed of navigation mode, air-to-air mode, air-to-ground mode. In air-to-air mode, HUD should provide the intuitive symbols for pilot to aim the target exactly in a short time. In this paper, we propose a design method to improve the visibility of the HUD Symbols.

• Atmosphere
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• v.22 no.4
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• pp.429-436
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• 2012

The performances of the Seoul National University Urban Canopy Model (SNUUCM) under different meteorological conditions (clear, cloudy, and rainy conditions) in summertime are compared using observation dataset obtained at an urban site. The daily-averaged net radiation, sensible heat flux, and storage heat flux are largest in clear days and smallest in rainy days, but the daily-averaged latent heat flux is similar among clear, cloudy, and rainy days. That is, the ratio of latent heat flux to net radiation increases in order of clear, cloudy, and rainy conditions. In general, the performance of the SNUUCM is better in clear days than in cloudy or rainy days. However, the performance in simulating sensible heat flux in clear days is as poor as that in rainy days. For all the meteorological conditions, the performance in simulating latent heat flux is worst among the performances in simulating net radiation, sensible heat flux, and latent heat flux. The normalized mean error for latent heat flux is largest in rainy days in which the relative importance of latent heat flux in the surface energy balance becomes greatest among the three conditions. This study suggests that improvements to the parameterization of processes that are related to latent heat flux are particularly needed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.367-370
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• 2005

This paper investigated the sound characteristics in an apartment complex. The field measurement was conducted in order to examine the acoustical characteristics of the apartment complex in situ. As a result, it shows that there are around 3 sec. reverberation time and the additional sound reinforcements at the area of high height due to the surrounded buildings. Thus, 1:50 Scale model measurement and Raynoise computer simulation were carried out with insertion of the parapet and the canopy on the balcony. In case of a single building, the parapet was effective to reduce noise level at low floor levels, and the canopy was effective to reduce noise level at high floor levels. But it also shows that both the parapet and the canopy were not effective to reduce noise level at middle floor levels. In case of an apartment complex, the canopy was less effective to reduce noise level at each floor in comparison with case of the single building.

• Journal of the Korean Solar Energy Society
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• v.33 no.4
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• pp.70-79
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• 2013

These day cities experience serious climatic changes due to environmental load caused by disturbance in the circulation systems of water resources and energy. As technological improvement to respond to various climatic changes and disasters are also requested in the field of construction, inter-disciplinary studies linked to the establishment of sustainable environmental control and energy systems is required in a consilient perspective. This study aims to infer correlations in the impact of environmental changes caused by rooftop greening system on the photovoltaic power generation efficiency through computer simulation in an integrated perspective. By doing so, it seeks to provide basic study for developing a photovoltaic system integrated with building revegetation that is sustainable in environmental and resource aspects. A simulation showed that, in the case of sunshine hours in June, the green surface indicated temperature lowering effects of $9.19^{\circ}C$ on average compared to the non-green surface and temperature was $9.81^{\circ}C$ lower. Due to such greening effects, at the highest sunlight timepoint in June, Pmpp improved 119W and heat loss rate dropped 7.8%.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.343-343
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• 2023

식생피복(Vegetation cover)은 대기 중의 강우와 토양 사이에서 침식으로부터 표토를 보호하는 역할을 한다. 자유 낙하하는 강우의 물방울은 식생을 통과하면서 차단(interception), 수관통과(throughfall), 수간유하(stemflow)의 형태로 변화한다. 식생은 강우입자의 운동에너지와 수량을 감소시키고, 지표면에 도달하는 시간을 지연시킴에 따라 지표유출(overland flow) 저감에 기여한다. 유출수의 흐름과정에서 식물의 줄기, 낙엽, 뿌리 등은 유속을 감소시키는 장애물로 작용하여 궁극적으로 토양침식은 감소한다. 토양침식은 식생피복이 증가함에 따라 일반적으로 감소하며, 지수함수의 관계를 갖는다. 식생의 종류와 구조 그리고 잎의 모양 등에 따라 수문물리적인 반응이 달라진다. 캐노피를 갖는 지상식물(canopy cover plant)은 물방울의 운동에너지를 갖는 반면, 지피식물(ground cover plant)은 낙하고가 작기 때문에 운동에너지는 적으며, 특히 낙엽층은 지표면을 보호하여 토양침식의 저감효과가 더욱 크다. 산불지역의 식생피복에 따른 토양침식 측정 자료에 따르면, 강우운동에너지는 식생피복이 증가함에 따라 지상피복(canopy cover)에 의한 감소보다는 지면피복(ground cover)과 낙엽피복(litter cover)에 의한 감소효과가 상대적으로 컸다. 식생피복에 의해 차단되는 강우의 손실량보다 침투량 증가에 의한 손실량이 상대적으로 많았다. 낙엽피복에 대한 강우모의 실험 결과에 따르면, 낙엽의 피복율이 증가함에 따라 지수적으로 토양침식량은 감소하였다. 낙엽 피복율의 40% 이상은 토양침식량을 현격이 감소시킨 반면, 피복율의 70% 이상은 지표유출량을 현저히 감소시켰다. 낙엽 피복율이 70%이상이면, 유출계수가 33%가 감소하였으나, 토양침식민감도는 94%로 크게 감소하였다.