• Fire Science and Engineering
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• v.32 no.6
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• pp.15-21
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• 2018

This study examined the flow characteristics of fire smoke under pressurized air ventilation conditions by carrying out fire simulations on multi-compartment enclosure, including room, ancillary room and stair case. Fire simulations were conducted for the air-leakage test facility, which was constructed to measure the effective leakage area and aimed to improve the understandings of fire and smoke movement by analyzing the overall behaviors of fire smoke flow and pressure distributions of each compartment. The simulation results showed that the heat release rate of the fires was controlled sensitively by the amount of air supplied by the ventilation system. An analysis of the velocity distributions between the room and ancillary room showed that fire smoke could be leaked to the ancillary room through the upper layer of the door, even under pressurized air supply conditions. From these results, it was confirmed that the fire size and spatial characteristics should be considered for the design and application of a smoke control system by a pressurized air supply.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.2
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• pp.381-404
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• 2022

Forest fires inflict great losses of human lives and serious damages to ecological systems. Hence, numerous fire detection methods have been proposed, one of which is fire detection based on sensors. However, these methods reveal several limitations when applied in large spaces like forests such as high cost, high level of false alarm, limited battery capacity, and other problems. In this research, we propose a novel forest fire detection method based on image processing and correlation coefficient. Firstly, two fire detection conditions are applied in RGB color space to distinguish between fire pixels and the background. Secondly, the image is converted from RGB to YCbCr color space with two fire detection conditions being applied in this color space. Finally, the correlation coefficient is used to distinguish between fires and objects with fire-like colors. Our proposed algorithm is tested and evaluated on eleven fire and non-fire videos collected from the internet and achieves up to 95.87% and 97.89% of F-score and accuracy respectively in performance evaluation.

• Journal of Navigation and Port Research
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• v.42 no.4
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• pp.283-290
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• 2018

Due to the environmental factors of the sea, ship accidents always contain an inclination angle. The change in the ship affects not only the evacuation speed of passengers but also the fire growth in the ship. For this reason, when analyzing the fire, it is necessary to analyze the risks by considering conditions of inclination. In this study, the temperature that affects the fire was calculated by alteration of ship's heel and trim angle and analyzed using FLUENT. Based on fire occurrence position, evacuation should be done within 37 seconds under the condition of $-10^{\circ}$ heeling angle and 36 seconds under the condition of $-10^{\circ}$ trim angle. However, it was predicted that the evacuation will not be affected under the conditions of $+10^{\circ}$ heel angle and $+10^{\circ}$ trim angle. For these reasons, it is confirmed that when the ship is on fire, evacuation measures should be considered based on the heel and trim conditions as per the location of the fire.

• Structural Engineering and Mechanics
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• v.69 no.2
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• pp.193-204
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• 2019

This paper presents results from experimental and numerical studies on the response of steel-concrete composite box bridge girders under certain localized fire exposure conditions. Two composite box bridge girders, a simply supported girder and a continuous girder respectively, were tested under simultaneous loading and fire exposure. The simply supported girder was exposed to fire over 40% of its span length in the middle zone, and the two-span continuous girder was exposed to fire over 38% of its length of the first span and full length of the second span. A measurement method based on comparative rate of deflection was provided to predict the failure time in the hogging moment zone of continuous composite box bridge girders under certain localized fire exposure condition. Parameters including transverse and longitudinal stiffeners and fire scenarios were introduced to investigate fire resistance of the composite box bridge girders. Test results show that failure of the simply supported girder is governed by the deflection limit state, whereas failure of the continuous girder occurs through bending buckling of the web and bottom slab in the hogging moment zone. Deflection based criterion may not be reliable in evaluating failure of continuous composite box bridge girder under certain fire exposure condition. The fire resistance (failure time) of the continuous girder is higher than that of the simply supported girder. Data from fire tests is successfully utilized to validate a finite element based numerical model for further investigating the response of composite box bridge girders exposed to localized fire. Results from numerical analysis show that fire resistance of composite box bridge girders can be highly influenced by the spacing of longitudinal stiffeners and fire severity. The continuous composite box bridge girder with closer longitudinal stiffeners has better fire resistance than the simply composite box bridge girder. It is concluded that the fire resistance of continuous composite box bridge girders can be significantly enhanced by preventing the hogging moment zone from exposure to fire. Longitudinal stiffeners with closer spacing can enhance fire resistance of composite box bridge girders. The increase of transverse stiffeners has no significant effect on fire resistance of composite box bridge girders.

• Fire Science and Engineering
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• v.24 no.5
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• pp.68-78
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• 2010

The purpose of this study, fire officials during the field activities find causes fugitive dust of containing asbestos is the seriousness of the phenomenon is a threat case and through questionnaires, during on-site activities to prevent exposure to asbestos is effectively. Analysis of the relationship to field activities of fire officials and about the dangers of asbestos dust, asbestos cancer caused by asbestos, and to protect fire officials from the same disease like malignant mesothelioma, by varying the conditions of irrational, fire officials at the scene activities in advance of a deadly hazard is aimed to eliminate through optimization of organizational management and a safe and pleasant working conditions for fire officials through the deadly hazards at the scene of action is aimed to obviate. Also according to asbestos exposure by wearing protective equipment as well as thoroughly strengthen firefighting, firefighting awards to recognize the seriousness of the hazard factors, disease and provide compensation to the legal system, for diseases not yet recognized officially recognized by disaster supplemented by institutional, fire officials to improve morale and working conditions, etc. versus expectations is to improve public services.

• Fire Science and Engineering
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• v.24 no.5
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• pp.39-49
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• 2010

In order to find out the environment vulnerable to cigarette fire in which smoldering fire grows into flame fire, a cigarette combustion test and numerical analysis were performed using fallen leaves of P. densiflora and Q. variabilis. Tests were repeated five times on 2,304 conditions with four cases of fuel moisture content, six cases of velocity, two cases of cigaret location against direction of the wind, three cases of cigaret location against fallen leaves, two species of thickness of cigaret, two cases of slope conditions and two cases of fragileness of fallen leaves. Cigaret fire's flammability to the fallen leaves was monitored by analyzing heat transfer process using CFD (Computational Fluid Dynamic) under the most optimal condition through an ignition test on 2,304 conditions. The result of a cigaret fire ignition test for fallen leaves, found ignition in 197 conditions out of 2,304 conditions representing 8.6% while 13 conditions representing approximately 0.6% saw ignition across five repeated tests. The result of CFD analysis, the temperature of the bottom of fallen leaves was reached on self-ignition and pilot-ignition temperature.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.3
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• pp.357-364
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• 2022

The safety of a KTC-360 transport cask, a large-capacity pressurized heavy-water reactor transport cask that transports CANDU spent nuclear fuel discharged from the reactor after burning in a pressurized heavy-water reactor, must be demonstrated under the normal transport and accident conditions specified under transport cask regulations. To confirm the thermal integrity of this cask under normal transport and accident conditions, high-temperature and fire tests were performed using a one-third slice model of an actual KTC-360 cask. The results revealed that the surface temperature of the cask was 62℃, indicating that such casks must be transported separately. The highest temperature of the CANDU spent nuclear fuel was predicted to be lower than the melting temperature of Zircaloy-4, which was the sheath material used. Therefore, if normal operating conditions are applied, the thermal integrity of a KTC-360 cask can be maintained under normal transport conditions. The fire test revealed that the maximum temperatures of the structural materials, stainless steel, and carbon steel were 446℃ lower than the permitted maximum temperatures, proving the thermal integrity of the cask under fire accident conditions.

• Fire Science and Engineering
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• v.29 no.5
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• pp.23-28
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• 2015

Recently, structural materials have been developed to have high performance, and SM 520 has been developed and used for high-rise buildings. However, fires frequently occur in buildings, and the number of victims and amount of damage increase year by year. However, the evaluation of fire resistance performance for structural beams made of SM 520 is done with specimens made of ordinary structural steels with boundary conditions of a fixed beam, and the results are allowed for use in steel-framed buildings. This study analyzed the fire resistance performance of statistically indeterminate beams built with SM 520. The analysis used a fire engineering technique that includes mechanical and thermal data of SM 520 and heat transfer theory, and heat stress analysis was also conducted. The results from the analysis were compared with those from a statistically determinate beam made of ordinary structural steels.

• Fire Science and Engineering
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• v.21 no.1 s.65
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• pp.1-6
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• 2007

This paper investigated the fire and smoke behavior in the compounded multiplex theater using FDS with various spacial and boundary conditions to ensure the fire safety of the multiplex. The results showed that more rapid temperature increase and smoke can be induced near the exit door for the lower fire load duo to the horizontal smoke movement. The overuse of fire resistants can generate more smoke while delaying combustion rate, which can give adverse effect to the evacuation. The mal-function of the exhaust fan would obstruct smoke exhaust but also retard the function of sprinkler head.

• Journal of Korean Society of Steel Construction
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• v.19 no.2
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• pp.181-190
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• 2007

A fire-resistant steel with enhanced load-bearing capacity has been developed to enable structural elements such as columns and beams withstand exposure to severe fire conditions. To precisely evaluate the fire-resistant performance of structural elements that compose fire-resistant steels, mechanical properties such as yield strength and elastic modulus are essential. To obtain the mechanical database of fire-resistant steels at high temperatures, tensile tests at high temperatures were conducted on steels of two kinds of thicknesses. The results showed that the thickness difference could not affect the mechanical properties at a high temperature.