• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.117-127
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• 2015

This study investigated the smoke blocking and control systems for the safety of residents evacuation and for the prevention of smoke spread through the central corridor in the event of central corridor type of intelligent building fire. We offered additional ways of utilizing smoke ventilators and intake ventilation equipment and utilized CFD-based fire simulation program(FDS Ver.5.5.3) in order to analyze the effect. As a result, many differences in the smoke block effect, depending on the application of smoke ventilator and location of installation, was found. In addition, the result was found that larger effect was showed not in the case of application of smoke ventilator in central corridor only but application in fire room. The reason is that the smoke leakage is blocked primarily as air is flowed in the fire room through open door by operation of intake smoke ventilator in the public corridor and secondarily, the smoke leakage to the public corridor could be blocked as fire and smoke were released to the opened smoke ventilator continuously. Especially, the effect was maximized through complex interactions by applying smoke ventilator and intake ventilation equipment in corridor together rather than applying smoke ventilator and intake ventilation equipment independently. The proposed measure through this study shall be considered from architectural plan as one of ways for blocking from smoke spread to the central corridor in the central corridor type of intelligent building. In addition, flaws on regulation shall be established and supplemented.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.2
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• pp.117-125
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• 2015

Quantitative risk assessment (QRA) of railway is to create a variety of scenario and to quantify the degree of risk by a result of the product of accident frequency and accident. Quantitative risk Assessment is affected by various factors such as tunnel specifications, characteristics of the fire, and relation of smoke control and evacuation direction. So in this study, it is conducted that how the way of smoke control and the relation of smoke control and evacuation direction affect quantitative risk assessment with variables (the tunnel length (2, 3, 4, 5, 6 km) and the slope (5, 15, 25‰)). As the result, in a train fire at the double track tunnel (Area = $97m^2$), it is most efficient to evacuate to the opposite direction of smoke control regardless of the location of train in train fire. In addition, under the same condition, index risk in mechanical ventilation up to 1/10.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1006-1010
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• 2017

This paper describes the design and test of the thermal control and fire safety system for thermal control and the fire/explosion prevention of inside the compartment during the preparation and operation of the space launch vehicle at the launch pad. The system considered here is for the test launch vehicle which is being developed as part of the development of the Korean Space launch vehicle-II. This system applies the high pressure system based on the heritage of Naro launch vehicle. The selection of thermal control and fire safety system from high pressure and low pressure system is done in consideration of the characteristics of the launch pad gas supply system and the characteristics of launch vehicle, and the system configuration is also changed accordingly. As a result, it has been confirmed that the developed system satisfies the initial design conditions through the test. Moreover the system will be applied to the development of the Korean launch vehicle in the future.

• Geomechanics and Engineering
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• v.14 no.2
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• pp.107-113
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• 2018

Coal samples with different joints morphology were subjected to uniaxial compression experiments, cracks evolution was recorded by Nikon D5300 and acoustic emission (AE) energy signals were collected by AEwin Test for Express-8.0. During loading process, coal samples deformed elastically with no obvious cracks changes, then they expanded gradually along the trace of the original cracks, accompanied by the formation of secondary cracks, and eventually produced a large-scale fracture. It was more interesting that the failure mode of samples were all shear shape, whatever the original cracks morphology was. With cracks and damage evolution, AE energy radiated regularly. At the early loading stage, micro damage and small scale fracture events only induced a few AE events with less energy, while large scale fracture leaded to a number of AE events with more energy at the later stage. Based on the multifractal theory, the multifractal spectrum could explain AE energy signals frequency responses and the causes of AE events with load. Multifractal spectrum width (${\Delta}{\alpha}$), could reflect the differences between the large and small AE energy signals. And another parameter (${\Delta}f$) could reflect the relationship between the frequency of the least and greatest signals in the AE energy time series. This research is helpful for us to understand cracks evolution and AE energy signals causes.

• Steel and Composite Structures
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• v.30 no.4
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• pp.351-364
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• 2019

Earthquake and fire are both severe disasters for building structures. Since earthquake-induced damage will weaken the structure and reduce its fire endurance, it is important to investigate the behavior of structure subjected to post-earthquake fire. In this paper, steel-concrete composite beam-to-column joints were tested under fire with pre-damage caused by cyclic loads. Beforehand, three control specimens with no pre-damage were tested to capture the static, cyclic and fire-resistant performance of intact joints. Experimental data including strain, deflection and temperature recorded at several points are presented and analyzed to quantify the influence of cyclic damage on fire resistance. It is indicated that the fire endurance of damaged joints decreased with the increase of damage level, mainly due to faster heating-up rate after cyclic damage. However, cracks induced by cyclic loading in concrete are found to mitigate the concrete spalling at elevated temperatures. Moreover, the relationship between fire resistance and damage degree is revealed from experimental results, which can be applied in fire safety design and is worthwhile for further research.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.232-243
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• 2024

Purpose: Recently, large-scale forest fires caused by climate change, natural disasters, and human factors have been increasing every year in the East Coast and Taebaek Mountains region. Although forest fire extinguishing using helicopters is currently increasing, the need to introduce air force transport aircraft has continued to be raised due to the importance of early fire extinguishment to respond to large forest fires and the difficulty of extinguishing forest fires between sheep. This study seeks to present a plan for developing a post-fire management system for several aspects - achieving operational objectives, overcoming the operating environment, selecting a staging area, and efficient operation measures - to efficiently perform forest fire extinguishing missions using Air Force transport aircraft. Method: Based on literature research on forest fire extinguishing, forest fire extinguishing experiments using fixed-wing aircraft, and the operation status and operation method of forest fire extinguishing helicopters, the pros and cons of helicopter operation and the effects of large forest fire extinguishing using a large transport aircraft (C-130) Analyze the effectiveness of operation through analysis. Results: When extinguishing a large forest fire, an effective CM (Consequence Management) application plan was derived, including effective operation, control, command system, dispatch request, and forest fire extinguishment when integrating helicopter and fixed-wing aircraft (C-130). Conclusion: The application of the concept of CM (Consequence Management) is partially applied to some areas of chemical, biological, and radiological (CBRNE) protection in Korea, but efficient operation, control, and command systems are established when integrated operation of helicopters and large aircraft (C-130) in forest fire extinguishment. the concept of CM (Consequence Management), which is operated in advanced countries, was applied for safety management, dispatch requests, and forest fire extinguishing, thereby contributing to the establishment of a more advanced disaster and post-disaster management system.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.62-65
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• 2018

The rapid progress toward the 4th industrial society has led to possibilities of fire increase. It is pointed out that, though initial fire suppression is emphasized, the current legal systems do not sufficiently recognize the importance of initial fire suppression. In order to resolve this, problems of the current legal systems and regulations, as well as fire-fighting facilities to be equipped according to the size of specific fire-fighting objects, were diagnosed. Also, suggestions for improvement were provided through comparative analysis with relevant laws and technical regulations of Korea and other countries. According to fire safety standards such as NFPA, IMO, ISO, and Russian standards, automatic fire extinguishers are to be installed as per the adaptability criteria of fire extinguishers and automatic fire extinguishers. In Korea, the "Act on Fire Prevention and Installation, Maintenance, and Safety Control of Fire-fighting Systems" cover the types and scope of fire fighting facilities that include specific fire protection objects, such as electric room, power room, and substation room. This study has identified that, in case of a place with a floor area of less than $300m^2$, the installation requirement is not clearly specified. Therefore, in this study, fire extinguishing equipment and automatic fire extinguishing equipment to be added for each sub-use application are proved to have fire extinguishing performance of Class A, Class B, and Class C, respectively. In view of the fact that, in overseas standards, all space except containing such materials as Deep fire, metal fire and peroxide, can be installed with fire fighting equipment, a legal system for specifying the capacity units of fire fighting apparatus by application is, in this study, proposed.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.3
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• pp.348-355
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• 2007

To grasp a feasibility of back fire control by valve overlap period, back fire limit equivalence ratio was estimated with valve overlap period which has the same supply energy and positive intake pressure as valve overlap period $300^{\circ}\;CA$. As the result, it was shown that the smaller valve overlap period has the higher back fire limit equivalence ratio under valve overlap period $300^{\circ}\;CA$ as well as VOP $0^{\circ}\;CA$. This result means that expansion of back fire equivalence ratio by decreasing valve overlap period was caused by decrease of back flow duration of flame from in-cylinder to intake port than decrease of lower supply energy.

• Fire Science and Engineering
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• v.26 no.2
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• pp.40-52
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• 2012

This paper presents the uncertainty analysis results of fire modeling input parameters for motor control center in switchgear room of nuclear power plants. FDS (Fire Dynamics simulator) 5.5 was used to simulate the fire scenario and Latin Hyper Cube Monte Carlo simulations were employed to generate random samples for FDS input parameters. The uncertainty analysis results of input parameters are compared with those of the model uncertainty analysis and sensitivity analysis approaches of NUREG-1934. The study results show that the input parameter uncertainty analysis approach may lead to more conservative results than the uncertainty analysis and sensitivity analysis methods of NUREG-1934.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.1
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• pp.21-27
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• 2015

A conventional fire detection has been developed based on images captured from a fixed camera. However, It is difficult to apply current algorithms to a flying Quad-rotor to detect fire. To solve this problem, we propose that the fire detection algorithm can be modified for Quad-rotor using Ego-motion compensation. The proposed fire detection algorithm consists of color detection, motion detection, and fire determination using a randomness test. Color detection and randomness test are adapted similarly from an existing algorithm. However, Ego-motion compensation is adapted on motion detection for compensating the degree of Quad-rotor's motion using Planar Projective Transformation based on Optical Flow, RANSAC Algorithm, and Homography. By adapting Ego-motion compensation on the motion detection step, it has been proven that the proposed algorithm has been able to detect fires 83% of the time in hovering mode.