• Fire Science and Engineering
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• v.23 no.4
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• pp.73-78
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• 2009

This paper investigated the combustion properties of the Pinus rigida, Castanea sativa, and Zelkova serrata which are grown in Korea using the cone calorimeter. The heat release rate and smoke production for these species were measured. With respect to an increase of retardant properties attributed to char formation, Zelkova serrata showed good properties compared with that of Pinus rigida and Castanea sativa. The Castanea sativa has high $CO_{peak}$ Yield and high $CO/CO_2$ Yield compared with that of Pinus rigida and Zelkova serrata.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.350-352
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• 2013

야외에서 촬영된 영상은 안개나 연무 등에 의한 화질 저하가 나타난다. 이를 해결하기 위하여 안개제거를 위한 여러 장의 영상, 추가정보를 이용하는 안개제거 방법과 한 장의 영상을 이용한 안개제거 방법들이 제안되어왔다. 본 논문에서는 한 장의 영상에서 안개나 연기를 제거하여 가시성이 향상된 영상을 제공하는 방법을 제안한다. 이를 위하여 본 논문에서는 안개영상 모델에 대한 2차원 방정식 풀이를 통해 원 영상에 안개가 어느 정도의 비율로 섞여있는지를 나타내는 전달률(transmission rate)을 계산하고, 계산된 전달률을 이용하여 안개가 제거된 영상을 구한다. 제안된 방식은 기존 방법들과 달리 필터를 사용하지 않고 화소단위의 연산만을 사용하므로 후광효과가 발생하지 않고, 연산량이 매우 적어 실시간 처리가 가능하다.

• Fire Science and Engineering
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• v.30 no.2
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• pp.75-80
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• 2016

In the wake of expanding and overpopulating urban areas, traffic congestion has been worsening increasingly, causing huge economic losses. In a bid to effectively use the space of metropolitan areas, the construction and operation of a double deck tunnel has been on the rise. On the other hand, a lower height of a double deck tunnel is expected to generate more smoke and soot in a fire than other usual tunnels. Therefore, it is undesirable to apply the standard for fire intensity or smoke generation, which were designed for existing road tunnels. A part of an effort to propose a design fire curve that is useful for double deck tunnel, is intended to obtain and analyze the fire characteristics in a double deck tunnel through a real scale fire test. The test was conducted according to the fire scenario with one passenger car and two passenger cars; the monitored fire intensity was a maximum of 2.4 MW and 3.5 MW, respectively.

• Fire Science and Engineering
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• v.28 no.6
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• pp.52-57
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• 2014

The present study suggests the fundamental method for the prediction time of the fire origin by analyzing the combustion phenomenon of inflammable material in the building structure. The heat release rate (HRR) with time variant is evaluated for the interphone as a inflammable material, which is opted from the fire incidents in the stairwell. the fire dynamics simulator (FDS ver. 6.1) is applied in order to analyze the difference of the smoke inflow time to the downstair from the fire event area with various fire pattern. The results show that the maximum inflow time difference for the case of the interphone made from ABS materials is about 4.93 times with the input conditions of heat flux values and the environment in the FDS for the fixed stairwell which composed of total volume $291.3m^3$, floorage $23.3m^2$ and the height of each floor 2.5 m. This research can be practical information for the application method of simulation scheme with experimental data to the fire Identification.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.204-210
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• 2019

In case of a fire inside a tunnel, unlike ordinary roads, it is very difficult for a driver to obtain visibility, and a large accident is highly likely to occur. In this study, the smoke behavior, visible distance, and CO concentration of a jet fan were analyzed using the NIST fire simulation (FDS). All analyses were set to HRRPUA (Heat Release Rate Per Area) 3.6MW/m and all the analysis times were set to 600s. In all analyses by CFD, the results were confirmed at y=30m and y=110m, and smoke behavior analysis, visible range analysis, and carbon monoxide concentration were confirmed according to the diameter and flow rate. As the size and flow rate of the jet fan increased, the visibility distance was high at y=30m, and the concentration of carbon monoxide was also confirmed to be 0 ppm. Therefore, proper setting of the jet fan diameter and flow rate will be an excellent solution for fires in tunnels, and taking refuge at upstream area of a re-ventilated fan can reduce the number of casualties.

• Korean Journal of Environmental Agriculture
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• v.23 no.2
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• pp.99-103
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• 2004

This study was carried out to determine impacts of burning of barley straw produced from rice-barley double cropping paddy field on air quality by investigating emissions of greenhouse gases ($CO_2$, $CH_4$ and $N_2O$), air pollution gases (CO, $SO_2$, $H_2S$, $NH_3$ and NO) and particulate matters (PM 10 and PM 2.5). When the barley straw at a rate of 4.5 t/ha was burned at open status, the emitted GHGs amounts were $CO_2$ 376.8 kg/l0a, $CH_4$ 1.56 and $N_2O$ 0.06. The amount of CO emission was the largest among air pollution gases. These results showed that the range of $45{\sim}55%$ of total C in barley straw was emitted as $CO_2-C$, followed by CO-C ($6.4{\sim}5.9%$) and $CH_4-C$ ($0.5{\sim}0.7%$). As far as moisture content in barley straw is concerned, the higher moisture content that the barley straw contains, the larger amount of air pollution gases and the higher portion of PM 2.5 in PM 10 were emitted when it burned. In case of harvesting time of barley straw, emission amounts of greenhouse, air pollution gases and PM 2.5 portion in PM 10 had tendency to increase when earlier harvested barley straw was burned.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.616-620
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• 2013

In this work, the combustive properties of the swine manure, poultry manure, and mixtures based on the resource recycling-energy were investigated. After the specimens were dried to a constant weight by dry oven, combustive properties were tested by the cone calorimeter (ISO 5660-1). It was found that the peak effective heat of combustion (PEHC) in the swine manure (78.72 MJ/kg) has risen due to more amount of the hydrocabon compared with poultry manure (69.41 MJ/kg), also the swine manure increased both of the higher $CO_2$ production rate (0.1959 g/s) and total smoke release rate (THRR) ($419m^2/m^2$) than those of the poultry manure. However, both of the CO production release (0.0996 kg/kg) and CO production rate (0034 g/s) in the poultry manure increased due to more amount of the inorganic contents compared with swine manure. Thus, the high combustion energy is expected to generate depend on the hydrocarbon content.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.163-170
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• 2013

In general, images of outdoor scenes often contain degradation due to dust, water drop, haze, fog, smoke and so on, as a result they cause the contrast reduction and color fading. Haze removal is not easier problem due to the inherent ambiguity between the haze and the underlying scene. So, we propose a novel method to solve single scene dehazing problem using the region segmentation based on graph algorithm that has used a gradient value as a cost function. We segment the scene into different regions according to depth-related information and then estimate the global atmospheric light. The medium transmission can be directly estimated by the threshold function of graph-based segmentation algorithm. After estimating the medium transmission, we can restore the haze-free scene. We evaluated the degree of the visibility restoration between the proposed method and the existing methods by calculating the gradient of the edge between the restored scene and the original scene. Results on a variety of outdoor haze scene demonstrated the powerful haze removal and enhanced image quality of the proposed method.

• Fire Science and Engineering
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• v.33 no.4
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• pp.105-111
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• 2019

In South Korea, smoke control systems are designed according to the fire safety standards NFSC501 and NFSC 501A. However, there is a problem in that the design values are incompatible when measuring the performance of the system after the design construction for calculating the leakage crack area described in the standards. Therefore, we compared the standards for smoke control systems from South Korea, Japan, and the United Kingdom. In South Korea, designs are conducted uniformly according to the NFSC 501A Manual, but in Japan and the United Kingdom, designs consider smoke temperature, duct loss, and fire floor air supply. Furthermore, they use larger values than in South Korea.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.244.3-245
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• 1979

1. 수율계수 함수의 영향 : 유가 배양에 있어서 수율 계수가 제한 기질 농도의 함수일 경우에 대한 연구를 수행하였다. 사용한 수율 계수 함수는 기질 농도에 대하여 선형 함수였으며 목적함수는 중간 대사 물질의 생산량이었다. 1-가) 수율 계수 함수의 기울기가 음의 값으로 적어짐에 따라 제한 기질의 공급속도가 증가되었다. 1-나) 일반적으로 초기의 얼마 동안은 회분 배양에서와 같이 공급 속도가 거의 없었으며 그후 전환점 이후에 가서야 공급 속도가 증가하였다. 1-다) 전환점 이후에서도 처음에는 대부분의 경우에 공급속도가 음의 값으로 부터 시작하여 증가하기 시작하였다. 1-라) 어떤 경우에는 배양 초기부터 공급 속도가 양의 값으로부터 시작하였으나 곧 감소하였다가 다시 증가하는 비 단조형 변화를 보였다. 1-마) 전환점 이후에서 공급 속도가 증가하는 형태에서도 처음에는 선형 증가를 보이다가 나중에 지수적 증가를 보였다. 1-바) 위와 같은 공급 속도의 변화에 따른 발효조 내의 제한 기질 농도의 변화는 초기에는 가능한 최대치를 유지하다가 전환점 이후에는 갑자기 감소하는 형태를 취하였다. 2. 목적 함수의 영향: 목적 함수가 균체량과 생성 중간 대사물질 량의 선형 결합일 때 대하여 연구하였다. 선형 결합 계수로는 균체량과 생성대사 물질의 상대적인 값어치를 취하였다. 2-가) 허용 최대 균체 농도가 제한되어 있는 상황 하에서 생성 대사 물질의 상대적인 값이 증가 할수록 목적 함수가 증가하였다. 2-나)생성대사 물질의 상대적인 값이 증가할수록 전환점의 위치가 줄어들었다. 2-다) 생성대사 물질 상대적 값의 단위 증가에 대한 목적 함수는 균체량을 감안하지 않은 야마네박사의 결과에 수렴하였다. 2-라) 공급 속도는 상대 값이 커질수록 줄어들었다. 2-마) 균체량의 시간에 대한 곡선은 상대값이 증가할수록 감소하고 전형적인 분기점 형태의 변화를 보였다.변이 뚜렷하여 이로 인한 외임파강내의 염증성병변이 뚜렷이 나타나 있으며 와우관의 특히 기저회전에서의 유모세포의 손실이 심한 것으로 보아 중이염으로 인한 골도의 고음역에서의 손실이 발생함을 알 수 있다.A group), vinclozolin, procymidone, tetradifon cypermethrin, 그리고 fenvalerate(B group)에서는 70% 이상의 회수율을 얻었고, 20%의 ethyl acetate/hexane을 사용하여 분석한 경우는 5%나 10%의 ethyl acetate/hexane을 사용하여 분석했을 때보다 좋은 결과를 나타내어 전체 16종의 농약 중 14종에서 75% 이상의 회수율을 얻었으나, alachlor와 bifenthrin은 매우 낮은 회수율을 보여서 ethyl acetate와 hexane의 혼합용매가 이들 두 농약성분의 분석에는 적합하지 않은 용출 용매임을 알 수 있었다.NO_2의$ 급성 중독증상으로서는 눈, 코를 강하게 자극하고 폐충혈, 폐수종, 기관지염, 폐염 등을 일으킨다. 만성 중독시에는 만성폐섬유와 및 폐수종을 일으킨다. (4) $오존(O_3)$ Ozone은 자동차 배기가스에서 나오는 $NO_2$ gas 및 탄화수소와 작용하여, PAN이라는 자극성 물질을 생성시키는 광학적 Smog의 주요소로 알려져 있다. 자극적인 냄새가 있음으로 불쾌감을 주고 비, 인후점막의 전조감과 두통이 오며 폐기능을 저하시키며 더욱 진행되면 폐충혈, 폐수종 등을 일으킨다 (5) Smog에 의한 건강피해 대표적인 것이 1952.12.5~12.8까지 4일간 영국 Lon-don에서 계속된 Smog사건이며, 이 사건으로 말미암아 호흡기질환 사망율이 사건전보다 사건기간 중 혹은 사건후에 5~10배의 증가율을 보였다. 이때 Smog의 주원인은 연료의 불완전 연소에 의한 연기와 이때 발생