• 한국항공운항학회지
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• 제24권3호
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• pp.55-61
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• 2016

Among the method of aerial fire firefighting, the indirect attack is efficiency way to protect main facilities and it is the aerial fire line construction. According to this study is suggested the fire line construction strategy of indirect attack by helicopter suitable Korea forest fire on theory consideration of indirect attack and experience in practical scene. This study defined that main key points of the fire line construction are accuracy, large quantity, and quickness. Main protection facilities are devided as caution area, warning area, danger area and concern area. Also, it suggested stage-by-stsge from 1 step to 3 step for the aerial fire firefighting correspondence strategy and the fire line construction model. I regard that this study's indirect attack method of the aerial fire firefighting of the fire line construction may be understand about indirect attack tactics and application of indirect attack which is assistance to raise of capability of the aerial fire firefighting with effectiveness and efficiency.

• 한국안전학회지
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• 제33권3호
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• pp.21-26
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• 2018

Approximately 20% of the total fire is electrical fire, and electrical energy is a potential source of heat. Large-scale fault currents that occur during a line ground fault flow into electric utility poles, electric power equipment, or electric appliances of the customer, and cause simultaneous electrical fire. In this paper, we investigated the possibility of fire through the change of fault current flowing in faulty and sound feeder in case of 1 line ground fault in 22.9 kV distribution line. We propose a fire investigation analysis method for simultaneous multiple electrical fire such as evidence analysis method, and fault current occurrence confirmation method in case of fire accident by analyzing the fault current occurring in the ground fault in the distribution line using EMTP, electric power system analysis program.

• 한국안전학회지
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• 제25권2호
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• pp.18-23
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• 2010

This paper describes a cause of fire accidents on power system fire DC electric traction vehicles. We investigated fire scene of power line for DC electric traction vehicles. From analysis results, the cause of fire on power line turned out line to ground fault between a feeder of electric power services(pantagraph) and DC electric traction vehicle roof. Fire accident of DC electric traction vehicles be assumed that electric sparks had been produced between the pantagraph and the power line conductor by repetitively making contact and separation, maybe if some material like branches get in between connecting rod it makes progress line to ground fault. ZnO arresters are widely used to protect DC electric traction vehicles against overvoltages caused by lightning or switching surges. However, the arresters are deteriorated by commercial overvoltages and/or lightning one. The deteriorated arresters could lead power failures, such as line to ground fault by a thermal runaway resulting from the increases in leakage current even in a nominal power system voltage. Finally, the power failures would be causative of the fire accident.

• 대한안전경영과학회지
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• 제16권3호
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• pp.165-173
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• 2014

This study is about determination of fire origin by using analysis of shadow that was recorded CCTV data at the fire scene. This analysis is based on straight and radiate nature of light. At fire experiment with about 1m flame, we conformed that 2-dimensional extension line is focused at the bottom of the fire. If the fire is burning at the same level with shadow, it indicate the point of origin exactly. In 3-dimensional analysis that connect extensional line between distinctive points the shadow and the objet, the line focused in the ${\emptyset}$ 50cm-circle. We estimate the reason of that is because of the character of combustion of gases. The line indicate not the point of origin but the flame that is over the point of origin. thus, you have to consider the line indicate the flame when you do 3-dimensional analysis.

• 한국화재소방학회논문지
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• 제24권5호
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• pp.26-31
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• 2010

본 연구는 우리나라의 각종 소.중형 및 대형 산불의 공중진화 경험을 바탕으로 산불행태와 헬기의 현장운영을 고려한 산불 공중진화 방화선 구축형태 및 진화방법에 대하여 제안하였다. 산불확산은 현장의 지세, 경사, 바람, 수종 등에 영향을 받으므로 공중진화 방화선을 구축할 때에는 연소방향 및 형태, 강도 등을 분석한 후 진화작업을 실시하여야 하며, 특히 연기로 인하여 시계가 방해 받으므로 안전을 고려해 진화작업을 하는 것이 중요하다. 따라서 본 연구에서는 산불현장 공중진화 경험을 바탕으로 A형에서 M형까지 13개의 산불 공중진화 방화선 구축형태 및 진화방법을 제안하였다.

• 한국안전학회지
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• 제32권6호
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• pp.16-21
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• 2017

Fire or electrical problem while DC electric traction vehicle operation caused by various reasons can lead to not only suspension of the operation, but also severe aftermath such as massive casualty. In this paper, fire analysis on DC electric traction vehicle caused by electrical breakdown on line breaker, which is in connection with the power supply, is presented. When the electric arc, the by-product of frequent line breaker operation, is not fully diminished, it leads to electrical breakdown and fire. Especially, electrical breakdown can be easily induced by the open-and-close operation of inner contractor inside line breaker, eventually followed by ground fault and generation of transient current. Electric arc is consequent on the ground fault and acts as possible ignition source, leading to fire. Also, during the repetitive operation of the line breaker, the contactor is separated each other and some copper powder is generated, and the copper powder provided breakdown path, resulting in fire.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.241-247
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• 2008

This paper describes a cause of fire accidents on power system for DC electric traction vehicles. We investigated fire scene of power line for DC electric traction vehicles. From analysis results, the cause of fire on power line turned out line to ground fault between a feeder of electric power services(pantagraph) and DC electric traction vehicle roof. Fire accidents of DC electric traction vehicles be assumed that electric sparks had been produced between the pantagraph and the power line conductor by repetitively making contact and separation, maybe if some material like branches get in between connecting rod it make progress line to ground fault. ZnO arresters are widely used to protect DC electric traction vehicles against overvoltages caused by lightning or switching surges. However, the arresters are deteriorated by commercial frequency overvoltages and/or lightning one. Deteriorated arresters could lead power failures, such as line to ground fault by a thermal runaway resulting from the increases in leakage current even in a nominal power system voltage. The power failures, such as line to ground fault would be causative of the fire accidents.

• 한국안전학회지
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• 제29권5호
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• pp.47-53
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• 2014

Despite the automatic fire alarm system, according to the national fire data system of national emergency management agency, the fires account for 40,932 incidents, 2,184 injuries and about 430 billion won in property losses in 2013. Since the conventional automatic fire alarm system has several weaknesses related to electrical signal such as noise, surge, lighting, etc. Most fires are mainly caused by electrical faults, mechanical problem, chemical, carelessness and natural. The electrical faults such as line to ground fault, line to line fault, electrical leakage and arc are one of the major problems in fire. This paper describes the development of a novel real-time fire monitoring system algorithm including fault detection function which puts the existing optic smoke and heat detectors for fire detection with current and voltage sensors in order to utility fault monitoring using high accuracy DAQ measurement system with LabVIEW program. The fire detection and electrical fault monitoring with a proposed a new detection algorithm are implemented under several test. The fire detection and monitoring system operates according to the proposed algorithm well.

• 대한안전경영과학회지
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• 제9권2호
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• pp.49-57
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• 2007

This Study is to suggest a method of effect evaluation of forest fire on governor station in shrub land. Theoretically, to evaluate effects of forest fire, it is combined that Spread Rate of Forest Fire, Flame Model, and Thermal Radiation Effects Model; i.e. a travel time of forest fire is calculated by Spread Rate of Forest Fire, fire-line intensity is calculated by Flame Model, and effects of fire-line intensity is affected by Thermal Radiation Effects Model. With the aforementioned method, we could carry out the effect evaluation of forest fire on governor station in shrub land and could distinguish scenarios to need protection plan from all scenarios.

• 대한안전경영과학회지
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• 제13권2호
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• pp.275-282
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• 2011

A core device of foam system is the in-line eductor and it is the device to mix the foam liquid into liquid solution proper to the use density and the mixture ratio must be kept regularly regardless of changing fluid condition of the front and rear end of the in-line eductor. However, if the flux of the pressurized water changes, the mixture ratio is not kept regularly, and so it becomes a cause which a performance of fire-extinguishing deteriorates in discharging foam liquid. I devise a method to improve it that the metering orifice type in-line eductor is improved into the metering venturi type in-line eductor, the fluctuation of the mixture ratio to the flux change of the pressurized water is minimized and the performance of fire-extinguishing is kept regularly. As this method is simple in its structure and can be designed at a low cost, it helps for maintenance as well. In the future, it seems to need the research for the metering nozzle type in-line eductor in the future.