• 한국안전학회지
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• 제19권3호
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• pp.1-8
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• 2004

This study aims to derive the operation method of a comprehensive ventilation system which is capable of providing passengers with safe exit paths from platforms in onboard fire situations. To accomplish this, the airflow distributions in subway platforms under 6 types of tunnel vent system were calculated in addition to having analyzed diffusion behaviors of smoke and heat exhaust in such states by performing 6 kinds of different ventilation scenarios in a 3-D Fire Dynamic Simulation (FDS) simulation model. In order to recommend the mechanical smoke exhaust operation mode, Subway Environmental Simulation(SES) is used to predict the airflow of the inlet and outlet tunnel for the subway station to clarify the safety evaluation fir the heat and smoke exhaust on subway fire events.

• Computers and Concrete
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• 제21권6호
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• pp.637-647
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• 2018

Numerical approach using finite element method has been used to evaluate the behaviour of reinforced concrete frame structure subjected to fire. The structure is previously designed in accordance with Eurocode standards for the design of structures for earthquake resistance, for the ductility class M. Thermal and structural response are obtained using a commercially available software ANSYS. Temperature-dependent nonlinear thermal and mechanical properties are adopted according to Eurocode standards, with the application of constitutive model for the triaxial behaviour of concrete with a smeared crack approach. Discrete modelling of concrete and reinforcement has enabled monitoring of the behaviour at a global, as well as at a local level, providing information on the level of damage occurring during fire. Critical regions in frame structures are identified and assessed, based on temperatures, displacements, variations of internal forces magnitudes and achieved plastic deformations of main reinforcement bars. Parametric analyses are conducted for different fire scenarios and different types of concrete aggregate to determine their effect on global deformations of frame structures. According to analyses results, the three-dimensional finite element model can be used to evaluate the insulation and mechanical resistance criteria of reinforced concrete frame structures subjected to nominal fire curves.

• 한국산학기술학회논문지
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• 제15권7호
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• pp.4626-4633
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• 2014

국가 간 교류 급증 및 이상기후현상으로 인해 새로운 교통기반시설 확보에 대한 관심이 증대되면서 해중터널에 관한 연구가 진행되고 있다. 하지만 이는 전 세계적으로 거의 초기 단계이며, 특히 재해로부터 안전을 도모하기 위한 다양한 연구가 필요한 실정이다. 본 연구에서는 해중터널의 구조 성능 평가 중에 화재가 발생하였을 경우에 화재열이 해중터널에 미치는 영향성을 분석하고자 한다. 해중터널의 해석 대상 모델은 강합성 중공 RC 해중터널을 대상으로 해석을 수행하였으며, 다양한 화재가 발생하였을 경우에 화재열이 해중 터널 구조에 미치는 영향에 대해서 해석적으로 분석하였고, 또한 이를 방지할 수 있는 방지 기법을 해석적으로 검토하였다.

• 해양환경안전학회지
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• 제26권4호
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• pp.317-326
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• 2020

본 연구에서는 LNG 추진선에서 배관의 파손으로 천연가스가 누출되었을 때 누출공의 크기별 플래시 화재, 과압, 복사열에 따른 피해범위를 ALOHA(Areal Location of Hazardous Atmospheres)를 이용하여 산출했다. 그리고 민감도 분석을 위해 환경 변수(풍속, 대기온도, 대기 안정도)와 공정 변수(배관 압력, 배관 길이)로 구분하여 다양한 시나리오별 피해영향범위를 분석했다. 그 결과 환경 변수에 따른 피해범위는 플래시 화재에 의한 피해범위가 가장 컸으며 다음으로 과압, 복사열 순서로 큰 피해범위를 나타냈다. 그리고 공정 변수에 따른 피해범위를 산출한 결과 배관의 압력과 길이, 누출공의 크기와 관계없이 플래시 화재에 의한 피해범위가 가장 컸으며, 환경 변수와 동일하게 과압, 복사열 순서로 높은 피해범위를 보였다. 또한 누출공의 크기가 클수록 환경 변수와 공정 변수가 피해범위에 큰 영향을 주었으며 제트 환재에 의한 피해범위는 환경 변수에 비해 공정 변수에 의한 피해범위가 더 큰 것을 알 수 있었다.

• 한국CDE학회논문집
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• 제16권5호
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• pp.370-379
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• 2011

The increasing complexity of complex buildings, such as high-rise buildings and underground subway stations, presents new challenges to firefighters. In a fire in complex buildings, the importance of the collaboration between firefighters is clear. The increased demand on firefighter training for such environment is now evident. Due to cost, time, and safety issues, it is impossible to experience a real fire in such environments for training. In addition, the use of real fire for training does not enable repeatable training and the evaluation of the training is difficult. We developed a team-based firefighter training simulator for complex buildings using the virtual reality technology. It provides the training and evaluation of firefighting and mission-based team training. To model real fire phenomena in virtual space, a numerical analysis method based on fire dynamics is used. To achieve an immersive virtual environment, an augmented reality technique for the compensation of real world image and a haptic technique for heat experience are adopted. The developed training simulator can help the firefighter to respond to large and complex firefighting scenarios, while maintaining the safety of the trainees.

• 한국전산유체공학회지
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• 제14권3호
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• pp.115-122
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• 2009

Numerical methods are applied to simulate the smoke behavior in a ventilated tunnel using large eddy simulation (LES) which is incorporated in FDS (Fire Dynamics Simulator) with proper combustion and radiation model. In this study, present numerical results are compared with data obtained from experiments on pool fires in a ventilated tunnel. The model tunnel is $182m(L){\times}5.4m(W){\times}2.4m(H)$. Two fire scenarios with different ventilation rates are considered with two different fire strengths. The present results are analyzed with those from LES without combustion and radiation model and from RANS ($\kappa-\epsilon$) model as well. Temperature distributions caused by fire in tunnel are compared with each other. It is found that thermal stratification and smoke back-layer can be predicted by FDS and the temperature predictions by FDS show better results than LES without combustion and radiation model. The FDS solver, however, failed to predict correct flow pattern when the high ventilation rate is considered in tunnel because of the defects in the tunnel-inlet turbulence and the near-wall turbulence.

• 한국시뮬레이션학회논문지
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• 제17권4호
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• pp.143-152
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• 2008

미래전에 있어서, 전투 초기단계의 대화력전 능력은 적을 무력화 시키는데 핵심역할을 수행한다. 본 논문에서는 효율적인 대화력전 수행방안을 제안하였다. 이를 위해, CEP를 사용한 명중확률을 산출한 후 대화력전 작전시 활용 가능한 새로운 사격제원 계산에 적용하였다. 새로운 표적제원의 타당성 검증을 위해 MANA 모델을 사용하여 시뮬레이션을 수행하였다. UAV 운용여부 등을 포함한 다양한 시나리오 상황 하에서 시뮬레이션 수행 결과, 새로운 사격제원산출 방법을 사용한 명중률이 기존의 BTCS 사격제원에 의한 명중률 보다 우수한 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제53권2호
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• pp.466-473
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• 2021

Fire protection is one of important issues to ensure safety and reduce risks of nuclear power plants (NPPs). While robust programs to shut down commercial reactors in any fires have been successfully maintained, the concept and associated regulatory requirements are constantly changing or strengthening by lessons learned from operating experiences and information all over the world. As part of this context, it is necessary not only to establish specific fire hazard assessment methods reflecting the characteristics of research reactors and educational reactors but also to make decisions based on advancement encompassing numerical analyses and experiments. The objectives of this study are to address fire simulation in the control room of an educational reactor and to discuss integrity of digital console in charge of main operation as well as analysis results through comparison. Three electrical fire scenarios were postulated and twenty-four thermal analyses were carried out taking into account two turbulence models, two cable materials and two ventilation conditions. Twelve supplementary thermal analyses and six subsequent structural analyses were also conducted for further examination on the temperature and heat flux of cable and von Mises stress of digital console, respectively. As consequences, effects of each parameter were quantified in detail and future applicability was briefly discussed. On the whole, higher profiles were obtained when Deardorff turbulence model was employed or polyvinyl chloride material and larger ventilation condition were considered. All the maximum values considered in this study met the allowable criteria so that safety action seems available by sustained integrity of the cable linked to digital console within operators' reaction time of 300 s.

• 디지털산업정보학회논문지
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• 제19권4호
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• pp.117-126
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• 2023

Traditional markets, formed naturally, often feature aged buildings and facilities that are susceptible to fire. However, the lack of adequate fire detection systems in these markets can easily lead to large-scale fires upon ignition. Therefore, this study was conducted with the aim of detecting fires in traditional markets, utilizing thermal imaging cameras for data collection and the YOLOv8 model for object detection experiments. Data were collected in the night markets within traditional markets of xx city and by simulating fire scenarios. A comparative analysis of the Nano and XL models of YOLOv8 revealed that the XL model is more effective in detecting fires. The XL model not only demonstrated higher accuracy in correctly identifying flames but also tended to miss fewer fires compared to the Nano model. In the case of objects other than flames, the XL model showed superior performance over the Nano model. Taking all these factors into account, it is anticipated that with further data collection and improvement in model performance, a suitable fire detection system for traditional markets can be developed.

• Journal of Advanced Marine Engineering and Technology
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• 제37권8호
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• pp.946-952
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• 2013

선박의 Ro-Ro 구역이나 특별범주구역의 화재방호를 위해 설치하는 고정식 수계소화설비의 개발 및 실용화를 위해, 특히 방수량이 적으며 관련기준에서 요구하는 성능요건을 만족하는 미분무 노즐을 개발하고자 실물화재실험을 수행하였다. 본 설비의 화재시나리오는 크게 두 가지로 트럭화물화재와 승용차화재로 구분되며, 각각 고정 설치된 미분무 노즐과 화원과의 세 가지 위치에 대한 시나리오로 이루어져 있다. 모든 화재실험은 30분간 진행되었으며 천장부의 가스온도와 우드펠릿의 손상율, 타깃합판의 착화여부로 판단되었다. 본 논문은 두 가지 화재실험 중 조건이 더욱 까다로운 트럭화재용 미분무 노즐의 결과를 위주로 방수압력과 방수량, 미분무수의 유동특성에 따른 화재실험결과와 화재진압특성을 고찰하였으며, 수십 회의 반복실험 결과 분당 약 40 L의 유량을 가지는 저압 미분무 노즐로 Ro-Ro구역의 화재진압이 가능한 것으로 나타났다.