• Journal of computational fluids engineering
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• v.14 no.3
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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.

• Journal of Sensor Science and Technology
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• v.33 no.5
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• pp.298-304
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• 2024

In Korea, fires are the second most common type of disaster, causing large-scale damages. The installation of fire detectors is legislated to prevent fires and minimize damage. Conventional fire detectors have limitations in initial suppression of failures because they detect fires when large amounts of smoke and heat are generated. Additionally, frequent malfunctions in fire detectors may cause users to turn them off. To address these issues, recent studies focus on accurately detecting even small-scale fires using multi-sensor and deep-learning technologies. They also aim at quick fire detection and thermal decomposition using gas. However, these studies are not practical because they overlook the heavy computations involved. Therefore, we propose a fast and accurate fire detection system based on multi-sensor and deep-learning technologies. In addition, we propose a computation-reduction method for selecting sensors suitable for detection using the Pearson correlation coefficient. Specifically, we use a moving average to handle outliers and two-stage labeling to reduce false detections during preprocessing. Subsequently, a deep-learning model is selected as LSTM for analyzing the temporal sequence. Then, we analyze the data using a correlation analysis. Consequently, the model using a small data group with low correlation achieves an accuracy of 99.88% and a false detection rate of 0.12%.

• Journal of the Korean Society of Safety
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• v.20 no.2 s.70
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• pp.11-17
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• 2005

Rotational motion in the atmosphere around a fire may have a profound influence on the fire plume. This process underlies the occurrence of fire whirls. Fire whirls are rare but highly destructive phenomenon which were observed in a large forest, urban and building fires. The present study aims to investigate of the effect of rotation Strength on the fire whirl characteristics expeimentally. Experiments are performed for various sizes of fire source with different rotation strength. From the experimental observations, it is noted that the mean centerline temperature is gradually increased and mean radial temperature is decreased as increases rotation strength. The characteristic mean flame height of fire based on the visible observation is increased as increases of dimensionless swirl parameter, $\Omega/\alpha$, represented by swirl induced motion to buoyancy driven motion.

• Journal of the Korean Society of Safety
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• v.17 no.2
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• pp.69-75
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• 2002

Current fire safety in the construction sites has developed piecemeal over a considerable period of time. However, the law and regulation of fire safety is insufficient to protect fro in the construction sites. The frequency of fire in the construction sites is very rare but it brings longterm deterioration durability of building structure and large scale industrial calamity. There are many process of works and each work deals with many kind of flammable material, so it is very difficult to find a proper safety fire prevention. This study executed the questionnaire and fire experiment of the welding work to provide effective fire prevention counterplan.

• Fire Science and Engineering
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• v.2 no.2
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• pp.9-16
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• 1988

This study is intended to suggest some ideal measures available in the course of construction from the viewpoint of an architect to reduce damage of human lives and Properties caused by fire accidents in buildings. For this study, 7 buildings burnt by conflaguration in Seoul during the years of 1985 and 1987 are picked up, and 105 withnesses, who were present in one of them at them at fire, are traced for personal interview and respones to the written questionaire about 5 main issues; their perceptional behaviour, their emotional state at that time, their reactions to avoid danger, their escape routes, and their usual awareness to prevent fire. Some desirable measures suggested here are ;making Provisions to install fire centers in large buildings and underground structures in the fire fighting law, and requlating to compose fire units appropriate to the quantity of combustibles inside, limit the length of a blind corridor, furnish balustrade, and limit the width of the landing of the stairs in building code and regulations. Such measures should be considered from the time of planning to construct a building, and some drill and education in fire prevention is demanded for the occupants of the buildings too.

• Journal of the Korea Institute of Building Construction
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• v.20 no.4
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• pp.383-389
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• 2020

Accidents on construction sites involving fires do not occur as often as accidents involving falls from height or collapses. However, once a fire accident occurs, there is a high risk of a large number of casualties. Fire on construction sites is affected by working conditions and the types of activities the construction workers are engaged in at the sites. This study aims to identify activities and working conditions at construction sites that are vulnerable to fire, and analyse how they correlate with each other and how they affect the causes and consequences of fire accidents at construction sties. I analysed 40 fire accident reports and listed the situations vulnerable to fire at construction sites considering direct causes, activities, and working conditions. The most dangerous combination of fire hazards can be the heating devices used during rest/sleep in the office/cabin/storage during cold weather. The next most hazardous combination can be sparks arising from painting, waterproofing, insulation, plumbing, or welding/melting work in an underground or confined space.

• Journal of the Korea Safety Management & Science
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• v.21 no.4
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• pp.39-44
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• 2019

In this study, fire and evacuation safety of environmental energy facilities using fire and evacuation simulation was examined as part of performance-oriented design. The worst-case fire scenarios in which fire-fighting facilities such as sprinkler fire extinguishing and smoke control systems are not working, and the FDS analyzes the visibility, temperature distribution, and carbon monoxide concentration distribution through FDS. The safety was examined. As a result, it was proved that evacuation could limit the visibility, temperature, and carbon monoxide concentration in a smooth range, based on the safety standards set by relevant laws. In other words, it was possible to verify the safety of fire and evacuation for environmental energy facilities where a large amount of combustibles and fires coexist.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.87-88
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• 2019

In case of Korea, The Large-scale fire is consistently being such as 2015 Uijeongbu Fire, 2017 Jecheon Fire, 2018 Sejong Hospital Fire. Such a fire has a problem that the fire is spreading upper due to external flame spread. As a countermeasure the fire safety, the study about axial temperature prediction of external flame spread is consistently doing. But in korea, Vertical spandrel is specified as 40cm, and improvement is urgently needed. In this study, a repair material was selected to prevent the fire from spreading to a building where a flammable exterior material was installed and then pilot construction was carried out. Also, fire safety measures for buildings constructed with flammable exterior materials were examined.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.507-517
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• 1997

As structures are higher, large-sized and more complex, we should detect the fire at the beginning and cope with it to reduce the loss of mankind and the physical damage due to fire. So we have investigated and developed various kinds of fire detection system, and do the efforts for minimizing the nonfire alarm. As there exists a close relationship between the technology development and the market potential, a comparison between the number of fires in special buildings and detection types were made to find out market potential based on the annual statistics on fire products inspection. In addition, we have discussed the causes of nonfire alarm and the fire detection system and prospect the research trend of the fire detection system.

• Journal of the Korea Safety Management & Science
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• v.14 no.4
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• pp.31-37
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• 2012

Recently buildings are constructed in larger and higher scales and becoming more complex. However from small to large scale buildings and on construction sites there still are fire safety accidents that occur continuously. Therefore to improve fire safety plan, examining the actual fire safety management and understanding fire risk analysis Using Fire Modeling through Computer Simulation. On this study, the permissible evacuation times were estimated for smoke fall, temperature, CO concentration, viability, etc. Fire safety management plans for fire safety were suggested.