• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1332-1337
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• 2008

Fire model shall be verified and validated to reliably predict the consequences of fires within its limitations. This study aims to predict pool fire with two rooms using FDS and to coompare FDS simulation results with PRISME experimental data which can be applicable to the fire of nuclear power plant facility. Four different sizes of grid (0.08m, 0.1m, 0.125m, 0.2m) are used in the simulation and the simulated results of specific quantities such as temperature, chemical composition, heat flux and heat release rate are compared to the experimental data. From this study, the FDS simulation results with the finer grid resolution show better similarity and trend with pool fire experimental data. The sensitivity analysis and the selection of the proper size grid are essential to predict the consequences of pool fire with two rooms reliably.

• Proceedings of the KIEE Conference
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• 2005.10a
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• pp.139-144
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• 2005

In this paper, We are going to propose the fire protection system with using CAN(Controller Area Network). The larger, higher and deeper buildings are, the more dangerous people are when fire happens. We should be aware of the problems of prior fire protection system. Therefore, we construct embedded system based on CAN communication that is capable of N:N communication, and build independent fire protection system. If the fire is occurred on the building, the problem is that how fast we can detect the fire and put off it by using available system, this is major factor that reduces damage of our wealth, therefore in this studies We would like to design more stable system than current system. this system that is based on CAN communication which is available N:N communication constructs and is designed to compensate for each fault so that our aim is to reduce the line of system and cost of installation and to suppose future type fire protection system. We are simulated by NIST FDS(Fire Dynamics Simulator) to prove the efficiency of this system.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2009.04a
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• pp.327-332
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• 2009

2005년 발코니 확장이 합법화 된 이후로 공동주택인 아파트의 지속적인 증가와 재개발및 재건축이 이루어짐에 따라 상층부의 화재확대를 차단하는 발코니를 확장하는 세대가 증가하고 있으며, 기존의 아파트 또한 불법 발코니 확장을 하는 사례가 늘어나고 있다. 따라서 본 연구는 발코니의 화재 안전에 대한 역할의 중요성을 부각시키고자, 발코니유 무에 따른 상층부의 개구분출열기류확산실험을 모형실험을 통해서 실시 한 후 'NIST'에서 개발 된 FDS(Fire Dynamics Simulator)를 사용해 해석하였다. 실험과 FDS해석, 그리고 Trajectory를 비교하여, 종횡비에 따른 1:1인 창과 횡장창과 종장창에 대해 서로 다른 분출열기류를 보이는 것을 확인하였다.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.410-423
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• 2019

Fire suppression using a water mist nozzle directly above an n-Heptane pool in a fire compartment with a door opening was numerically investigated using the Fire Dynamics Simulator (FDS) for the purpose of application in nuclear power plants. Input parameters for the numerical simulation were determined by experimental measurements. Water mist was activated 10 s after the fire began. The sensitivity analysis was conducted for three input parameters: total number of cubic cells of 6032-2,926,400, droplets per second of 1000-500,000, and extinguishing coefficient of 0-100. In a new simple calibration method of this study, the extinguishing coefficient yielding the fire suppression time closest to that measured by experiments was found for use as the FDS simulation input value. When the water mist jet flow made contact with the developed fire, the heat release rate instantaneously increased, and then rapidly decreased. This phenomenon occurred with a displacement of the flame near the liquid fuel pool. Changing the configuration of the door opening with different aspect ratios and opening ratios had impact on the maximum value of the heat release rate due to the flame displacement.

• 한국생태학회:학술대회논문집
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• 2002.08a
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• pp.93-100
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• 2002

Dynamics of certain $N_2$fixing bacteria such as Rhizobium, Azospirillum and Azotobactor, nodule number in dominant legume, Atylosia trinervia, P-solubilizing bacteria, actinomycetes and fungi were studied in unburned and burned site of natural grassland, southern India. Population of $N_2$- fixing bacteria, P-solubilizing bacteria, fungi and nodule number in legume increased significantly in burned sites. On the other hand, the actinomycetes population remained unchanged. Thirty six species of fungi with tricalcium phosphate solubilizing ability were recorded. The most efficient P-solubilizing fungi recognised in the soils of the study sites are Absidia ramosa, Gongronella butlerii, Mortieralla spinosa, Mucor racemosus, Rhizopus nigricans, R. stolonifer, R. oryzae, Aspergillus fumigatus, A. nidulans, A. niger Theilavia terricola and Cheatomium lunasporium.

• The Korean Journal of Ecology
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• v.25 no.4
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• pp.227-234
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• 2002

Dynamics of certain $N_2$ fixing bacteria such as Rhizobium, Azospirillum and Azotobactor, nodule number in dominant legume, Atylosia trinervia, P-solubilizing bacteria, actinomycetes and fungi were studied in unburned and burned site of natural grassland, southern India. Population of $N_2$ - fixing bacteria, P-solubilizing bacteria, fungi and nodule number in legume increased significantly in burned sites. On the other hand, the actino-mycetes population remained unchanged. Thirty six species of fungi with tricalcium phosphate solubilizing ability were recorded. The most efficient P-solubilizing fungi recognised in the soils of the study sites are Absidia ramosa, Gongronella butlerii, Mortieralla spinosa, Mucor racemosus, Rhizopus nigricans, R. stolonifer, R. oryzae, Aspergillus fumigatus, A. nidulans, A. niger, Theilavia terricola and Cheatomium lunasporium.

• Tunnel and Underground Space
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• v.21 no.4
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• pp.274-280
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• 2011

Evacuation and Fatalities Simulation is one of the core technologies for performance based design. Recently, developed programs in foreign countries have limitations such as simple fatality calculation and coarse visual interface. This study developed an advanced evaluation program for evacuation and fatalities to overcome limitations of existing programs and improve various applications, i.e., an evacuation algorithm using elevators as well as evacuation stairs. In addition, the evaluation program can let users make a decision of fatalities from fire by coupling with FDS (Fire Dynamics Simulator) from NIST and realizes three-dimensional virtual space using a graphic module.

• Journal of ILASS-Korea
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• v.17 no.2
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• pp.64-70
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• 2012

Water mist fire suppression systems which use relatively small droplets of water with high injection pressure are increasingly being used in wider applications because of its greater efficiency, low flooding damage and low toxicity. However, the performance of the system significantly relies on the water mist characteristics and it requires better understanding of fire suppression mechanism of water mist. In the present study, computational fluid dynamics simulations were carried out to investigate cooling performance of water mist in heated chamber. The gas phase was prepared with natural convection heat transfer model for incompressible ideal case and then the effects of water mist injection characteristics on cooling capabilities were investigated upon the basis of the pre-determined temperature field. For the simulation of water mist behavior, Lagrangian discrete phase model was employed by using a commercial code, FLUENT. Smaller droplet sizes, greater injection angles and higher flow rates provided relatively higher cooling performance.

• Fire Science and Engineering
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• v.30 no.4
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• pp.103-110
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• 2016

While the demand for the gas system fire extinguishers increases every year, there are insufficient safety measures for assessing the extinguishing performance, such as system safety and reliability in the preparation of increasing demand, which has emerged as a social problem. One of the most critical causes of accidents occurring with the gas extinguishing system is pressure leakage from the extinguishing agent storage container. This is considered to be one of the critical factors on which the success of fire suppression depends. In this study, its safety measure was studied, Because it was deemed urgently necessary. The newly developed pressure leakage monitoring system is a system monitoring storage condition, pressure, leakage and discharge of the storage container related to agent concentration, which is one of the critical factors for fire suppression. This was developed to be applicable to the $CO_2$ and HFC-23 systems. Therefore, for structural safety analysis, the safety performance was verified by the fluid structure coupling analysis of the safety problems that may occur when the pressure leakage monitoring system is applied to the gas fire extinguisher. For analysis programs, the FloEFD program from Mentor Graphics was used for computational fluid dynamics analysis and ABAQUS from Dassault Systems was used for structural analysis. From the result of numerical analysis, the structure of $CO_2$ did not develop plastic deformation and its safety was verified. However, plastic deformation and deviation issue occurred with the HFC-23 monitoring system and therefore verified the structural safety of pressure leakage monitoring system by data obtained from redesigning and adjusting the condition of numerical interpretation three times.

• Journal of the Korean Institute of Gas
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• v.15 no.3
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• pp.31-38
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• 2011

In this study, we investigate simulation studies to confirm the removal of smoke through ventilation when the subway car is on fire and stopped in an underground subway tunnel, by using Fire Dynamics Simulator (FDS) which is being upgraded by NIST. The structure of subway tunnel and train for simulation modeling are based actual data from Seoul metropolitan subway. The main purpose of this study is to assure the removal efficiency of the ventilation when changing the ventilation capacity between 2.0 m/s and 3.0 m/s. The results of the study shows that carbon monoxide (CO) and carbon dioxide ($CO_2$) are reduced by about 35% as the ventilation capacity is increased by 0.5 m/s. This study also performs the grid sensitivity verification of FDS for improved accuracy of the results. To find the effective size of the grid, three cases are simulated and the results are compared.