• Fire Science and Engineering
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• v.15 no.1
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• pp.23-33
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• 2001

The utility tunnels are the important facility as a mainstay of country because of the latest communication developments. However, the utilities tunnel is difficult to deal with in case of a fire accident. When a cable burns, the black smoke containing poisonous gas will be reduced. This black smoke goes into the tunnel, and makes it difficult to extinguish the fire. Therefore, when there was a fire in the utility tunnel, the central nerves of the country had been paralyzed, such as property damage, communication interruption, in addition to inconvenience for people. This paper is based on the fire occurred in the past, and reenacting the fire by making the real utilities tunnel model. The aim of this paper is the scientific analysis of the character image of the fire, and the verification of each fire protection system whether it works well after process of setting up a fire protection system in the utilities tunnel at a constant temperature. The fire experiment was equipped with the linear heat detector, the fire door, the connection water spray system and the ventilation system in the utilities tunnel. Fixed portion of an electric power supply cable was coated with a fire retardant coating, and a heating tube was covered with a fireproof. The result showed that the highest temperature was $932^{\circ}c$ and the linear heat detector was working at the constant temperature, and it pointed at the place of the fire on the receiving board, and Fixed portion of the electric power supply cable coated with the fire retardant coating did not work as the fireproof. The heating tube was covered with the fireproof about 30 minutes.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.256-262
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• 2011

Currently among the several methods to estimate an environmental impact of products, Life Cycle Assessment (LCA) technique is mostly used. The Ministry of Environment has been performed the carbon footprint labelling to give the carbon record of product by using this method. But the calculation of carbon footprint in primary agricultural product which is raw material of the processed food cannot be made because there is lack of methodology and LCI DB at agriculture sector. Therefore, LCA carried out to estimate carbon footprint, and established LCI DB for complex fertilizers (21-17-17 1 kg, 17-21-17 1 kg, 15-15-15 1 kg, Unspecified 1 kg) in the production system. The result of LCI DB analysis focussed on the GHG, and it was observed that the values of carbon footprint were $2.42E+00kg\;CO_2-eq.kg^{-1}$ for 21-17-17, $2.10E+00kg\;CO_2-eq.kg^{-1}$ for 17-21-17, $2.23E+00kg\;CO_2-eq.kg^{-1}$ for 15-15-15 and $3.56E+00kg\;CO_2-eq.kg^{-1}$ for Unspecified. For the analysis of LCIA (Life Cycle Impact Assessment) on complex fertilizers in the production system, the carbon footprint from pre-manufacturing phase is contributed to 98.96%, 98.81%, 98.88% and 99.30% on each complex fertilizer with 21-17-17, 17-21-17, 15-15-15, and Unspecified, respectively. These results will be used in basic data for estimation of agricultural greenhouse gas emissions.

• The Korean Journal of Food And Nutrition
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• v.15 no.3
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• pp.215-219
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• 2002

Growth characteristics of sourdough lactic acid bacteria was investigated to obtain basic informations for sourdough starter. The optimum temperature and pH on bacterial growth and lactic acid production of Lactobacillus brevis UC-22 in sourdough broth were 35'E and around pH 5.5, respectively. And the optimum concentrations of the carbohydrate sources added to the broths was 2% maltose. The acidity significantly increased during growth by Lactobacillus brevis UC-22 fur 18 hours while pH significantly decreased during growth.

• Journal of the Society of Disaster Information
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• v.7 no.1
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• pp.75-85
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• 2011

In this study, the behavior were analyzed for the bow collision event. The model of protective Structure was consist of slab, RCP and non-linear soil spring. The ship was modeled by bow and midship. The bow model was composed by elastic-plastic shell elements, and the midship was composed by elastic solid element. According to the weight of the ship's change from DWT 10000 until DWT 25000 increments 5000. The head-on collision was assumed, its speed was 5knot. Analysis was carried out ABAQUS/Explicit. As the result, increasing the weight of the ship deformability in athletes and to increase the amount of energy dissipated by the plastic could be confirmed.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.100-100
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• 2021

IPCC 5차 보고서에 따르면 지구 평균 기온상승은 저위도 보다 극지방에서 더욱 뚜렷하게 나타나며 이러한 기후변화는 극지 생태계의 변화를 초래한다. 이러한 기후변화에 따른 극지 생태계의 변화를 분석 및 예측하기 위하여 지면-생태계 모형을 구축하고 극지방 생태계, 수문 및 탄소 순환 등을 모의하는 연구들이 많이 진행되고 있다. 최근 극지 지역에서는 기후변화로 인하여 화재 발생 빈도가 증가하고 있으며, 이로 인하여 극지 생태계뿐 아니라 물순환에 많은 영향을 미치고 있다. 하지만 지면-생태계 모형안의 화재 시뮬레이션은 화재의 원인 파악의 부족, 입력자료의 부족, 화재 역학 이해의 부족 등의 한계가 존재한다. 본 연구에서는 2001~2012년 동안 위성에서 관측된 화재면적 자료인 Global Fire Emissions Database (GFED) v4 자료와 지면-생태계 모형인 NCAR Community Land Model (CLM)-biogeochemistry (BGC) 와의 실시간 융합을 통하여 기존 화재 시뮬레이션의 한계점을 보완하고자 하였다. 기존 CLM-BGC 모형을 통한 증발산량, 화재 자료-모형의 융합을 통한 증발산량 결과와 Moderate Resolution Imaging Spectroradiometer (MODIS) 증발산량 자료와의 비교를 통하여 증발산량 모의에 화재의 중요성을 분석하고자 한다. 또한, 유출량 뿐만 아니라 토양수분의 변화를 시·공간적 변화를 분석함으로써 화재가 극지방 물순환에 미치는 영향을 나타내었다. 또한, 본 연구를 통하여 미래 기후변화에 따른 극지방의 생태계 및 물순환을 모의하기 위하여 화재 시스템 구축의 중요성을 제시하였다.

• Land and Housing Review
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• v.12 no.2
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• pp.109-120
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• 2021

Global warming due to increased carbon dioxide is perceived as one of the factors threatening the future. Efforts are being made to reduce carbon dioxide emissions in each industry around the world. In particular, environmental loads and impacts during the life cycle of SOC structures and buildings have been quantitatively assessed through a quantitative method called Life Cycle Assessment (LCA). However, the construction sector has gone through difficulty in quantitative assessment for several reasons: 1) LCI DB is not fully established; 2) the life cycle is very long; 3) the building structures are unique. Therefore, it takes enormous effort and time to carry out LCA. Rather than estimating carbon emissions with accuracy, this study aims to present a simplified estimation model that allows owners or designers to easily estimate carbon dioxide emissions with little effort, given that rapid and rough decisions regarding environmental load reduction are to be made. This study performs the LCA using data from 25 road construction projects across the country, followed by multiple regression analyses to derive a simplified carbon estimation model (SLCA). The study also carries out a comparative analysis with values estimated by performing a typical LCA. The comparison analysis shows an error rate of less than 5% for 16 road projects.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.237-241
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• 2010

Many policies have been implemented to mitigate the greenhouse gases in atmosphere overall of sectors. With considering the distinct characteristics of the food security, agricultural sector is no exception to this situation. To this regard, total amount of carbon which is emitted through all of the agricultural production process is calculated, and being based on this result, the demand for the introduction of agricultural production system with low carbon has been rising. Case studies on the application of life cycle assessment (LCA) technique to agricultural sector are found in many countries. For example, life cycle inventory (LCI) data bases of crop, farm infrastructure, fertilizer, farm machinery, and etc., have been constructed and provided by Ecoinvent (Swiss centre for life cycle inventories) of Swiss. In Japan, Top-down typed LCA methodology for agriculture is developed based on the inter-industry analysis, and is evaluated according to the productive method of crop. On the other hand, environmental impact assessment of agricultural system using LCA in Korea is just in the beginning stages. So it is required to assess environmental impact on agricultural fertilizer and pesticide, and to develop their flow modeling, and methodology of LCA of agricultural sector. Environmental impact assessment on agricultural materials, machinery, and infrastructure will also be carried out.

• Journal of the Korean Geographical Society
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• v.50 no.3
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• pp.277-287
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• 2015

This paper addresses limitations of land-change modeling application in the context of REDD (Reducing Emissions from Deforestation and forest Degradation). REDD is an international conservation policy that aims to protect forests via carbon credit generation and trading. In REDD, carbon credits are generated only if there is measurable quantied carbon sequestration activities that are additional to business-as-usual (BAU). A "reference level" is defined as simulated baseline carbon emissions for the future under a BAU scenario, and predictive land-change modeling plays an important role in constructing reference levels. It is tested in this research how predictive accuracies of two land-change models, namely Geographic Emission Benchmark (GEB) and GEOMOD, vary with respect to different spatial scales: Xishuangbanna prefecture and Yunnan province. The accuracies are measured by Figure of Merit. In this Chinese case study, it turns out that GEB's better performance is mainly due to quantity (e.g., how many hectares of forest will be converted to agricultural land?) rather than spatial allocation (e.g., where will the conversion happen?). As both quantity and allocation are crucial in REDD reference level setting it appears to be fundamental to systematically analyze accuracies of quantity and allocation independently in pursuit of accurate reference levels.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.1-2
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• 1999

시간과 공간의 구애를 받지 않는 양질의 음성, 화상, 문자정보의 교환을 위한 노력으로 디지털 휴대폰과 휴대용 컴퓨터가 등장하면서 음성과 문자정보의 교환분야에 커다란 진보를 이룩하였다. 그러나 현재는 휴대폰이 음성정보에 문자정보교환이 추가된 상황이기 때문에, 아직도 관련 정보교환기술 및 기기개발이 진행되고 있다. 앞으로 휴대폰과 휴대용 컴퓨터의 기능을 통합하고 화상정보까지 결합된 휴대용 정보기기를 위해서는 전자회로의 집적화 및 통신속도 증대가 필수적이다. 또한 이들 휴대용 정보기기를 구동시키기 위한 전력도 증가될 것으로 예측되기 때문에, 현재 전원으로 사용되는 2차전지보다 에너지 밀도가 더욱 증패된 전지가 요구될 것으로 예상된다. 그리고 내연기관의 배기에 의해 발생되는 환정오염문제를 해결하기 위한 방법중의 일환으로 전기자동차 개발이 진행되고 있으며, 이들 전기자동차에 2차전지를 장착하기 위해서 경제성이 있고, 고속충전이 가능하고, 안전성이 높은 고에너지 밀도의 2차 전지 개발이 요구되고 있다. 현재 2차전지는 음극재료나 양극재료에 따라 낚축전지, 니켈/카드륨(Ni/Cd) 전지, 니켈/수소(Ni/MH) 전지, 라륨 2 차전지등이 있으며, 전극재료의 고유특성에 의해 전위와 애너지 밀도가 결정된다. 특히 리튬 2차전지는 리튬의 낮은 산화환원전위와 분자량으로 인해 에너지 밀도가 높기 때문에 앞에서 언급한 휴대용 전자기기의 구동전원으로 많이 사용되고 있다. 리튬 2차전지는 음극 재료가 금속리튬인 경우는 리튬금속으로, 탄소재료인 경우는 리튬이온이라 하며, 한편으로 전해질이 고체 고분자이거나 혹은 역체 유기용매와 리튬염을 고분자와 혼성시킨 겔(gel)인 경우는 고분자로, 전해짙이 리튬염이 전리되어 있는 유동성 액체일 경우는 고분자를 생략하여 구분하고 있다. 즉 리튬금속 2 차전지(LB), 리튬이온 2 차전지(LIB), 리튬금속 고분자 2차전지(LPB), 리튬 이온 고분자 2차전지(LIPB)로 크게 구분된다. 금속리듐을 음극으로 사용하고 전해질로는 리튬염이 전리되어 있는 액체유기용매 를 사용한 리튬금속 2차전지는, 금속리튬전극이 충방전 과정을 반복하면서, 전리된 리튬이 균일하게 산화환원되지 못하고 표변에서 양극방향으로 성장하는 수지상 (dendrite) 현상으로 인해 안전성 확보에 문게가 있었다. 리튬과 알루미늄 합금형태로 음극에 사용한 동전형 전지는 상용화 되었지만, 이러한 단점을 개선하기 위해 리튬이온이 금속으로 석활되는 환원반응전위보다 높은 전위에서 전극재료가 충전되면서 리튬이온이 저장되고, 방전되면서 배출되는 탄소를 음극재료로, 그리고 리튬이온이 충방 전시 가역적으로 삼입 탈리되는 층상의 리튬금속산화물을 양극으로 구성하고, 엑체 전해질과 다공성 고분자 분리막을 사용한 것이 LIB이다. LIB에서 리튬이온의 이동이 가능한 액체전해질의 가능을 고분자 전해질이 대신함으로서 보다 높은 안정성을 확보 한 전지가 LIPB 이다. 또한 고분자 전해질을 사용한 경우 금속리튬상에서의 수지상 성장이 저하되는 현상이 관찰됨으로서, 이론용량이 3,860mAh/g 에 달하는 리튬금속 혹은 합금을 고분자 전지에서 음극으로 사용하고자 하는 2 차전지가 LPB 이다. 리튬 2차전지는 비록 1989년 액체전해질을 사용한 금속리튬 2차전지의 실패전력을 안고있지만 궁극적으로는 이론적으로 최대의 에너지밀도를 가지고 있는 LPB를 지 향할 것으로 예상되지만 가까운 장래에 실현되기는 어려울 것이다. 따라서 향후의 라튬 2차전지의 전개방향은 현재의 LIB를 고분자 전해질을 채용하는 LIPB로 진행시커면서 저가의 전극재료개발을 지속적으로 추진할 것으로 예상된다. 현재 리튬 2차전지는 소형전지에 국한되고 있지만 전기자동차나 전력저장용으로 이를 대형화시커기 위해서는 열적특성이 우수하고 저가인 전극재료개발이 선행되야하기 때문에, 저가의 탄소재료와 코발트산화물을 대신할 수 있는 철, 망칸 또는 니켈산 화물의 개발이 필요하다.

• Fire Science and Engineering
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• v.21 no.3
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• pp.15-23
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• 2007

In the events of a fire in the residential building, highly flammable polyurethane foam sofa produce toxic smokes. In this type of fire, the residents of the building can be gotten into the difficulties of evacuating from the fire places or may be to death due to a lot of hot toxic gases. In this study, CFD simulations were carried out to study the effects of the openings of stairwell on the fire characteristics of fire room and stairwell. Also, analysis of fire hazard based on the tenability limits of fire and FED(fractional effective dose) was performed to evaluate the life safety of the residents of the building. In the fire room, maximum temperature was about $290^{\circ}C$, maximum CO concentration was about 4,740 ppm, and the time to incapacitation of residents in fire room was about t=144 s. In the stairwell, temperature and CO concentration in the condition of openings to be open were even lower than those in it to be closed. Time to the tenability limit with respect to smoke visibility in the stairwell with openings, which was open, was shorter than that of it without openings to be open. It has been shown from this study that opening the stairwell openings is able to decrease the fire hazards to the life safety in the multi-story residential building fire.