• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.189-190
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• 2010

Yeoju-Bo is a large massive concrete structures that require the reduction of working period of construction. In this study, we optimized the mix proportion of internal/external concrete and physical properties like compressive strength, semi adiabatic temperature rise in laboratory. And we also performed thermal analysis to verify the thermal cracking. Lastly we measured the hydration heat and the thermal cracking in site to verify the safety of massive concrete structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.259-260
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• 2010

This study is to investigate each mix property and physical properties and reduction properties of heat of hydration as basic experiment of reviewing the applicability of low calorific concrete.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.476-482
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• 2014

In this study, the characteristics of emulsified fuel and engine emissions were studied with engine dynamometer. Microexplosion took place in the combustion chamber. While combustion, emulsion fuel scattered to micro particles and it caused to smoke reduction. The heat produced from water vapour reduce the temperature of internal combustion chamber and it caused to inhibition of NOx production. It can be verified by the lower exhaust temperature of each ND-13 mode using emulsion fuel than that of MDO fuel. The NOx and smoke concentration were reduced by increasing water content in emulsion fuel. The power also decreased according to the increment of water content of emulsion fuel because emulsion fuel has low calorific value due to high water content than MDO. As a result of ND-13 mode test with 17% moisture content, it was achieved 24% reduction in NOx production, 76% reduction in smoke density, 11% reduction of $SO_2$ and 13% reduction in power loss.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.258-261
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• 2011

실내에서 화재가 발생한 경우에 매연의 크기분포 및 형상(morphology) 변화 특성은 경보장치의 작동 및 흡입에 의한 인체피해 등과 관련되어 중요한 연구 분야이다. 이와 관련하여 많은 연구가 이루어져 왔으나 실험에 의한 연구는 각 연구마다 결과치가 정량적 또는 정성적 측면에서 많은 편차를 보이고 있고, 이론적인 연구는 몇몇 특정 조건에 대하여 제한적으로 이루어져 있어서, 실재 구획화재에 적용하는 데는 어려움이 있다. 이 연구에서는 구획화재에 대하여 발열속도이력(history of heat release rate) 및 매연발생률(soot yield) 등에 따른 매연입자의 크기분포 및 형상 변화 해석을 위한 방법을 개발하였으며, 이를 유럽표준시험화재(EN54 Part7)에 규정된 폴리우레탄폼화재(TF4)에 대하여 시험 적용하였다. 이 방법에서는 입자의 크기분포방정식(dynamic equation for the discrete-size spectrum)을 푸는데 있어서 계산시간을 줄이기 위하여 결절방법(nodal method)을 도입하였으며, 또한 실재 화재에서의 매연입자의 성장에 따른 입경범위에 맞추기 위하여 분자운동영역(free molecular region)과 연속영역(continuum region)을 포괄하는 입자크기에 적용되는 충돌빈도함수(collision frequency function)를 사용하였다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.231-234
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• 2010

본 연구는 화재조건에 따른 화재실 바닥면에서의 열유속특성을 파악하기 위해 ISO-9705 표준화재실의 40% 축소모형공간에 대하여 화재실험을 수행하고 화재성상에 따른 열유속변화와 공간적 분포를 분석한다. 또한 모형실험에서 계측된 열유속을 Scaling Law를 적용하여 실규모 크기의 결과로 환산하고 이를 기존의 다른 연구결과와 비교분석함으로써 화재발생으로 인한 공간내 열유속의 축소법칙의 적용성을 파악하고자 한다. 실험에 사용된 연료는 천연가스, 메탄올, 에탄올, 헵탄, 톨로엔, 폴리스틸렌등이며 모형실험의 최대발열량은 450 kW 정도로 실규모로 환산시 약 4.4 MW이다. 실험결과 화재실바닥면의 열유속은 연층의 온도와 연료의 종류에 따라 차이를 보였으나 측정위치별 차이는 크지 않았으며 Scaling Law를 적용한 결과 화재실 상층부 온도가 약 $500{\sim}600^{\circ}C$ 정도에서 바닥면의 열유속은 약 $20kW/m^2$ 정도로 기존연구와 유사한 경향을 보였다. 본 연구는 화재공간 내 열유속 측정을 통해 전실화재로의 화재성장을 파악하고 화재실내부의 열적특성을 분석하기 위한 기초적인 자료를 제공하고자 한다.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1421-1432
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• 2018

Water soluble oil was obtained from the pyrolysis of coconut waste as a biomass at $600^{\circ}C$. It was studied that the combustion characteristics of bio-emulsion fuel by mixing and emulsifying 15~20% of water soluble oil which obtained from pyrolysis of coconut waste as a biomass and MDO(marine diesel oil) as a marine fuel. Engine dynamometer was used for detecting emissions, temperature, and power. The temperature of combustion chamber was decreased because the moisture in bio-emulsion fuel deprived of heat of evaporation in combustion chamber. While combustion, micro-explosion took place in the combustion chamber by water in the bio-emulsion fuel, MDO fuel scattered to micro particles and it caused to smoke reduction. The temperature reduction of combustion chamber by using bio-emulsion fuel reduced the NOx emission. The increasing of bio-oil content caused increasing water content in bio-emulsion fuel so total calorific value was reduced. So the characteristics of power was decreased in proportion to using the increasing amount of bio-emulsion fuel. Heavy oil as a marine fuel exhausts a lot of smoke and NOx. We expect that we can reduce the exhaust gas of marine engine such as smoke and NOx by using of bio-emulsion fuel as a marine fuel.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.639-643
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• 2007

The use of forest biomass resources produced by forest tending and residual forest biomass that was not gathered on commercial thinning or cutting area was estimated to be come into the spotlight as bioenergy sources in these days of new high oil price. With considering these problems, This study was investigated about possibility with biomass calculation and convertibility to fossil fuel in these area. Total forest tending area in the year 2005 was 294, 115 ha and the yield gathered from these area was $143,747m^3$. It is equivalent to biomass of 115,000 ton and caloric value of 533,199Gcal. However, the potential and additional yield that is residual in forest stands was 2,483,000 ton. It is equivalent to 11,133 billion won of oil which is 20 times of the actual yield produced by forest tending. Therefore, these amount of biomass has a substitution effect of the fossil fuel. Moreover, the residual biomass that is not gathered at commercial thinning and cutting area was 475,000 ton. It is equivalent to 2,206,235 Gcal of heating value and about 2,211 billion won of oil. This potential amount could be a new energy source to be a substitution effect of fossil fuel. It is time to be interested in the forest biomass as a renewable and environment-friendly resource and its substitution effect of fossil fuel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1419-1426
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• 2012

The heating and cooling energy load of the KNU plant factory was analyzed using the DesignBuilder. Indoor temperature set-point, LED supplemental lighting schedule, LED heat gain, and type of double skin window were selected as simulation parameters. For the cases without LED supplemental lighting, the proper growth temperature of lettuce $20^{\circ}C$ was selected as indoor temperature set-point together with $15^{\circ}C$ and $25^{\circ}C$. The annual heating and cooling loads which are required to maintain a constant indoor temperature were calculated for all the given temperatures. The cooling load was highest for $15^{\circ}C$ and heating load was highest for $25^{\circ}C$. For the cases with LED supplemental lighting, the heating load was decreased and the cooling load was 6 times higher than the case without LED. In addition, night time lighting schedule gave better result as compared to day time lighting schedule. To investigate the effect of window type on annual energy load, 5 different double skin window types were selected. As the U-value of double skin window decreases, the heating load decreases and the cooling load increases. To optimize the total energy consumption in the plant factory, it is required to set a proper indoor temperature for the selected plantation crop, to select a suitable window type depending on LED heat gain, and to apply passive and active energy saving technology.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.836-847
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• 2016

Water soluble oil was obtained by pyrolysis of biomass. The characteristics of emulsified fuel by mixing water soluble oil and MDO(marine diesel oil) and engine emissions were studied with engine dynamometer. Saw dust was used as biomass. Water soluble oil was obtained by condensing of water and carbon content with pyrolysis of saw dust at $500^{\circ}C$. Emulsion fuel was obtained by emulsifying MDO and water soluble oil by the water soluble oil mixing ratio of 10 to 20% of MDO. Exhaust gas detection was performed with engine dynamometer. While combustion, micro-explosion took place in the combustion chamber by water in the emulsion fuel, emulsion fuel scattered to micro particles and it caused to smoke reduction. The heat produced from water vapour reduce the temperature of internal combustion chamber and it caused to inhibition of NOx production. It can be verified by the lower exhaust temperature of each ND-13 mode using emulsion fuel than that of MDO fuel. The NOx and smoke concentration were reduced by increasing water soluble oil content in the emulsion fuel. The power also decreased according to the increment of water soluble oil content of emulsion fuel because emulsion fuel has low calorific value due to high water content than MDO. As a result of ND-13 mode test with 20% bio oil content, it was achieved 25% reduction in NOx production, 60% reduction in smoke density, and 15% reduction in power loss.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.987-996
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• 2015

According to the recent research results of the Ministry of Environment, the indoor air quality of large general hospitals and university hospitals(58 hospitals) exceeded the maintenance standard. On top of such indoor air quality, it is also desperately required to have the environment-friendly building design and also low carbon green design in accordance with the increase of hospital size and enlarged hospital buildings. Especially, the increase of carbon dioxide, heat, garbage, waste energy, exhaust heat from power plants and sewage heat in each medical center brings up lots of problems to the health of hospital patients and customers. Thus this study aims to convergently develop the green environment-friendly architecture design technology concerning the organic relations between each medical building, and technical development which should be introduced to the low carbon green environment-friendly architecture design based on the characteristics of each medical center in large-scale medical complex.