• Journal of the Korean Society of Safety
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• v.25 no.2
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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.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.37-42
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• 2006

The voltage drop in electrical circuits causes a heat accumulation of wiring. This heat could change the specific character of an insulator and deteriorate the dielectric strength so that it could affect an electric leakage, an electric ant a power failure and a fire caused by the short circuit. Therefore optimal design for voltage drop in electrical wiring became an important factor to ensure the safety and economical efficiency of electrical facilities. So in this paper, I analyzed consequences that voltage drop affects in electrical wiring in multi-distributed system used for low electrical system such as road lights, Building, subway station which needs securities for the public society. And I proposed voltage drops computation program and optimal design to ensure the safety and economical efficiency.

• Proceedings of the KSR Conference
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• 2008.11b
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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.

• Journal of the Korean Society of Safety
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• v.36 no.4
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• pp.62-70
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• 2021

Representative systematic accident analysis methods proposed so far include AcciMap, STAMP, and FRAM. This study used these three techniques to analyze a fire accident case that occurred during routine manufacturing work in a domestic chemical plant and compared the results. The methods used different approaches to identify the cause of the accident, but they all highlighted similar causal factors. In addition to technical issues, the three accident analysis methods identified factors related to safety education, risk assessment, and the operation of the process safety management system, as well as management philosophy and company culture as problems. The AcciMap and STAMP models play complementary roles because they use hierarchical structures, while FRAM is more effective in analyses centered on human and organizational functions than in technical analyses.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.47-55
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• 2021

When an abnormal landing occurs, aircraft structures should be designed to guarantee occupants survivability without preventing egress. To find out fire root causes at crash, lots of fixed aircraft crash tests were conducted. Appropriate crash load factors were established with the comprehension of structural behavior based on dynamic analysis and investigation of human tolerance. Cargo restraint criteria were set up considering passengers safety and operational cost while analyzing past cargo aircraft accident data using a probabilistic approach. Reviewing results of past crash tests, current crash landing load factor was appreciated physically, medically, and economically.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.195-204
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• 2023

The drone's battery system uses lithium-ion or lithium-polymer batteries, and it is known that the cause of fire during the disposal process after using the drone is combustible gas from the battery being discarded. Most of the batteries in the disposal process generated oxygen, but a small amount of flammable gas was also generated, and a large amount of chlorine ions and sulfates were also detected in the equipment used for treatment. If a system that detects this early is configured, it will be possible to reduce the risk of accidents caused by discarded batteries.

• Journal of the Korean Society of Safety
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• v.38 no.4
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• pp.23-31
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• 2023

Revising the Occupational Safety and Health Act led to enacting and revising related laws and systems, such as placing fire observers in hot workplaces. However, the operating standards in such cases are still ambiguous. Although fire accidents occur through multiple and multi-step factors, the hazards of fire accidents have been identified in this study as individual rather than interrelated factors. The aim has been to identify multiple factors of accidents, outlining fire and explosion accidents that recently occurred in the domestic manufacturing industry. First, major keywords were extracted through text mining. Then representative accident types were derived by combining the main keywords through the co-word network analysis to identify the hazards and their relationships. The representative fire accidents were identified as six types, and their major hazards were then addressed for improving safety measures using the identification of hazards in the "Risk Assessment" tool. It is found that various safety measures, such as professional fire observers' training and clear placement standards, are needed. This study will provide useful basic data for revising practical laws and guidelines for fire accident prevention, system supplementation, safety policy establishment, and future related research.

• Annual Conference of KIPS
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• 2010.04a
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• pp.334-337
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• 2010

디지털 선박 운행시 예기치 못한 상황에 의한 선박 내 화재나 충돌 등 긴급 상황 발생 시에 대형의 해난 사고가 발생할 수 있다. 이에 본 논문에서는 선박 상태를 자체 진단하여 모니터링하고 위험 분석을 통해 관리할 수 있는 시스템을 구현하고자 한다. 해양 디지털선박의 환경, 상황을 수집할 수 있는 무선 센서를 이용하여 수집된 환경 정보를 분석하는 시스템을 제안하였으며, 센싱된 데이터를 분석하기 위하여 역전파 신경망을 설계하였다. 300개의 데이터 집합을 사용하여 역전파 신경망을 실험한 결과 약 96%의 정확도를 가졌다. 제안된 시스템은 하드웨어 (UStar-2400 ISP, UStar-2400, Wireless sensors) 부분과 소프트웨어 부분(User Interface module)으로 구성되며 소프트웨어 부분은 HOST PC에 삽입된다. 그리고 시스템의 정확도를 개선하기 위하여 전방향 에러 정정 시스템(LDPC)을 구현하였고 진단된 결과는 CDMA 방식으로 전송하여 해양디지털선박 감지 모니터링 시스템을 구현했다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.663-664
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• 2020

안전함과 편리함을 추구하는 현대 사회에서 사람들은 각종 스마트기기에 가까워져 있다. 휴식을 취하는 가정에서도 역시 사람들은 스마트폰과 각종 웨어러블 기기가 일상이 되었고, 가전제품 또한 사물 인터넷화되며 사람들의 편의성에 보탬이 된다. 본 논문에서는 다가오는 4차산업혁명인 사물인터넷에 다가가는 주제를 선정하였고, 사람들이 가정에서 휴식을 취할 때 온습도, 미세먼지 농도를 사용자 지정 값에 의하여 자동 환기하여 쾌적한 환경 조성에 도움을 준다. 모든 측정값은 가정 내에서 블루투스 통신을 통해 결과를 표시하도록 하였다. 그리고 부하의 전원과도 연결하여 손쉽게 전원제어 역시 원격으로 가능하도록 구현하였다. 또한, 외출 시 가스 누출 사고와 화재 발생을 와이파이 통신 환경을 통해 원격으로 앱에 경보를 제시하고 누출된 측정값을 도식하면서 큰 2차 피해로 이어지기 전에 초동조치가 가능하도록 설계하였다. 사용자의 편의와 안전성을 주제로, 사람들에게 유익한 기능을 제공하고 앞으로의 4차산업혁명인 사물인터넷과의 연계 역시 기대할 수 있다.

• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.9-21
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• 2024

Static-electricity-induced fires and explosions persistently occur every year, averaging approximately 80 and 20 cases annually according to fire statistics provided by the National Fire Agency and industrial accident statistics provided by the Ministry of Employment and Labor, respectively. Despite the relatively low probabilities of these accidents, their potential risks are high. Consequently, effective risk assessment methodologies and accident investigation strategies are essential for efficiently managing static-electricity hazards in fire- and explosion-prone areas. Accordingly, this study aimed to identify the causal variables essential for accident investigations, thereby facilitating risk assessments and the implementation of effective recurrence prevention measures to mitigate static-electricity hazards in fire-and explosion-prone regions. To this end, industrial accident statistics recorded over the past decade (2012 to 2021) by the Ministry of Employment and Labor were analyzed to identify major fire and explosion incidents and related industrial accidents wherein static electricity was identified as a potential ignition source. Subsequently, relevant investigation reports (63 cases) were thoroughly analyzed. Based on the results of this analysis, existing electrostatic fire and explosion risk assessment techniques were refined and augmented. Moreover, factors essential for investigating electrostatic fire and explosion disasters were delineated, and the primary causal variables necessary for effective risk assessments and scientific investigations were derived.