• Fire Science and Engineering
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• v.28 no.5
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• pp.37-43
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• 2014

In the case of interior fire in an apartment building, contamination of vestibule area by fire smoke before air fan operating when fire doors are open makes the evacuation of people very difficult. In order to investigate the effect of heat release rate (HRR) and interior opening on fire flow velocity, numerical simulations using Fire Dynamics Simulator were carried out. In simulations, actual dimensions and configuration of an apartment building were considered and interior leakage and HRR were varied. From simulation results, it was found that fire flow velocity distribution is significantly influenced by HRR and interior opening resulting in the change of the location of a neutral plane. Also, it is shown that there is a larger difference of the fire flow velocity between upper and lower part of the fire door when the neutral plane becomes closer to the ceiling.

• Fire Science and Engineering
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• v.34 no.2
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• pp.22-29
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• 2020

In this study, the fire patterns, heat emissions, and smoke generated by means of fire tests developed for representative combustibles in residential facilities were analyzed from among seven fire types. These combustibles were selected in a previous study to simulate real-world situations and professionalism required while dealing with these types of fires and develop the field commander training content. Consequently, the maximum heat dissipation was recorded as 728.6 kW, followed by the dissipation measured from the combination of a mattress and electric blanket, desk and chair, and TV and mattress. The total heat emission of sofas (226.2 MJ) and the combination of mattress and electric blanket (2,259.5 ㎡) was recorded. In this study, the scope of the tests was limited to the fire characteristics and characteristics of the combustibles, and it is expected that a simulation using various data acquisition methods and FDS would be performed and evaluated at a later stage.

• Fire Science and Engineering
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• v.33 no.6
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• pp.20-27
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• 2019

In this study, a new function with higher accuracy for fire heat release rate prediction was developed. The 'αt²' curve, which is the major exponential function currently used for fire engineering calculations, must be improved to minimize the prediction gap that causes fire system engineering inefficiency and lower cost-effectiveness. The newly developed prediction function was designed to cover the initial fire stage that features rapid growth based on logistic function theory, which has a more logical background and graphical similarity compared to conventional exponential function methods for 'αt²'. The new function developed in this study showed apparently higher prediction accuracy over wider range of fire growth durations. With the progress of fire growth pattern studies, the results presented herein will contribute towards more effective fire protection engineering.

• Fire Science and Engineering
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• v.26 no.2
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• pp.90-96
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• 2012

Since vertical flame spread speed on exterior materials is much faster than horizontal fire, analysis of its fire characteristic is required. For the study of vertical fire pattern created by penetrating windows or openings from the exterior wall of buildings, the research is based on the fire simulation for an aluminum-complex-panel with which is commonly used as exterior materials and consists of polyethylene core material. As a result, the flame reaches the 2nd floor after 135 seconds in the early stage of fire, the 10the floor after 470 seconds and the 30th floor, the highest floor, after 711 seconds. The result shows that fire spread abruptly expands on upper floor due to stack effect of a turbulent flow or exterior materials. In consequence, we can confirm a serious problem that a conflagration of a building through an opening that is equipped with the exterior-materials spreads into interior of building at that same time.

• Spatial Information Research
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• v.21 no.6
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• pp.43-55
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• 2013

Recently, the research to visualize and to reproduce evacuation situations such as terrorism, the disaster and fire indoor space has been come into the spotlight and designing a model for interior space and reliable analysis through safety evaluation of the life is required. Therefore, this paper aims to develop simulation model which is able to suggest evacuation route guidance and safety analysis by considering the major risk factor of fire in actual building. First of all, we designed 3D-based fire and evacuation model at a subway station building in Incheon and performed fire risk analysis through thermal parameters on the basis of interior materials supplied by Incheon Transit Corporation. In order to evaluate safety of a life, ASET (Available Safe Egress Time), which is the time for occupants to endure without damage, and RSET (Required Safe Egress Time) are calculated through evacuation simulation by Fire Dynamics Simulator. Finally, we can come to the conclusion that a more realistic safety assessment is carried out through indoor space model based on 3-dimension building information and simulation analysis applied by safety guideline for measurement of fire and evacuation risk.

• Fire Science and Engineering
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• v.34 no.4
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• pp.87-95
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• 2020

This study evaluates the safety of an asylum through a fire simulation of building Type traditional markets. We derive the building's indoor temperature, use the observed variation in temperature gradient to calculate the temperature of the main structure, and finally compares the time required to attain the limit temperature of the structure its time of escape. To ensure improved security of the asylum, the government has proposed a fire-resistance improvement plan for the major structural parts of buildings are not safe with thickness of 0.01 m and 0.035 m. F.ire-resistance reinforcement for small - and medium-sized vehicles is more than 0.025 m, in thickness; moreover safety can be ensured for medium and large-sized vehicles fire using fire resistant reinforcement of over 0.035 m. Accordingly, in order to ensure the safety of an asylum, fire-resistant reinforcement measures may be considered.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.4
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• pp.133-140
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• 2008

The purpose of this study is to provide response methods to minimize the damage from chemical terrorism in a naturally ventilated indoor system using several types of dispersion simulations. Three chemical warfare agents such as sarin(GB), phosgene and chlorine gas which have high potential to be used in terror or to be involved with accidents were selected in this simulation. Fire dynamic simulation based on Large Eddy Simulation which is effective because of less computational effort and detailed expression of the dispersion flow was adopted to describe the dispersion behavior of these agents. When the vent speed is 0.005m/s, the heights of 0.1 agent mass fraction are 0.9m for sarin, 1.0m for phosgene and 1.1m for chlorine gas, and the maximum mass fraction are 0.27 for all three agents. However, when the vent speed is increased to 0.05m/s, the heights of 0.1 agent mass fraction become 1.6m for all three agents and maximum mass fraction inside the room increase to 0.70 for sarin, 0.58 for phosgene and 0.53 for chlorine gas. It is shown that molecular weight of the agents has an important role for dispersion, and it is important to install ventilation system with height less than 1.6m to minimize the damage from chemical toxicity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1661-1670
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• 2016

In this paper, we present a risk prediction system and customized evacuation pathfinding algorithm in fire scenarios. For the risk prediction, we apply a multi-level clustering mechanism using collected temperature at sensor nodes throughout the network in order to predict the temperature at the time that users actually evacuate. Based on the predicted temperature and its reliability, we suggest an evacuation pathfinding algorithm that finds a suitable evacuation path from a user's current location to the safest exit. Simulation results based on FDS(Fire Dynamics Simulator) of NIST for a wireless sensor network consisting of 47 stationary nodes for 1436.41 seconds show that our proposed prediction system achieves a higher accuracy by a factor of 1.48. Particularly for nodes in the most reliable group, it improves the accuracy by a factor of up to 4.21. Also, the customized evacuation pathfinding based on our prediction algorithm performs closely with that of the ground-truth temperature in terms of the ratio of safe nodes on the selected path, while outperforming the shortest-path evacuation with a factor of up to 12% in terms of a safety measure.

• Journal of Navigation and Port Research
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• v.36 no.1
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• pp.21-26
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• 2012

Recently, vessel hijacking by pirates has been a big issue around the world. For example, the hostages of VLCC "SAMHO Dream" were released for a large sum of ransom. On January 20, 2011 "SAMHO Jewelry" succeeded releasing all of the 21 crews on the vessel by attacking the pirates in international waters for the first time since the founding of the Naval Force. Furthermore, the "HANJIN Tianjin" crews evacuated to the Citadel promptly and were rescued by the navy. As hijacking of Korean vessels by pirates is increasing, various safety measures must be implemented. As a matter of fact, the standard for ship's facilities has been partially revised and setting up an evacuation shelter on all vessels sailing dangerous zone has been reinforced. This research aims to discuss crew Citadel installation on vessels intended for long haul. In addition, it will look at measures against potential gas flow in the event of pirate armed attacks and fire outbreak onboard a vessel. It will also assess the optimal number of crew Citadels theoretically. Lastly, the optimal number of shelters in the event of fire outbreak will be discussed based on an FDS simulation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.69-73
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• 2011

Unlike land fires, Fires on board a ship are not likely to be extinguished by skilled human resources using a variety of fire fighting equipments, but have to be brought under control on board a ship itself despite of difficult task. There are more cases of deaths from suffocation by smoke than from an increased temperature by heat in fires on board ships, because crew fail to secure a sufficient visibility range enough to escape from the scene of a fire or to leave the ship as early as possible. On the assumption that the height of ship's accommodation area increases from 2.0m to 2.3m comparable to the height of apartments on the ground in Korea, behaviors of fire smokes between the cases of 2.0m and 2.3m heights were compared and analyzed. Based on the blue print of the existing Training Ship "Hanbada", a new blueprint with the 30 cm height adjustment was additionally created. FDS (Fire Dynamic Simulator), which was created by the NIST in the United States and is the most widely distributed simulator for fires, was used to conduct a simulation and predict results. The results of simulation on the basis of temperature of $60^{\circ}C$ showed a safe evacuation period of time at the position 10m apart from the scene of a fire to increase by 55.8 seconds, when the height of ship's accommodation area increased from 2.0m to 2.3m. The results of simulation on the basis of visibility range of 6m showed the safe evacuation periods of time at the positions 10m, 20m and 30m apart from the scene of a fire to increase by 27.1 seconds, 109.2 seconds and 73.3 seconds, respectively, as the height of ship's accommodation area increased from 2.0m to 2.3m. This means that crew can escape more safely from a scene of fires on board when the height of ship's accommodation area is increased and equal to the height of living room in a building on land.