• Fire Science and Engineering
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• v.30 no.5
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• pp.9-17
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• 2016

In the case of a medium length road tunnel, the installation of a smoke control facility is not mandatory so users can suffer considerable injuries if a fire breaks out. Therefore, this study analyzed the high-temperature air and toxic gas generated by fire proliferating with time when a smoke barrier is not installed and when the installation interval is 100, 150, 200, and 250 m through 3-dimensional numerical analysis, evacuation simulation, and Quantitative Risk Assessment Methodology targeting the medium length road tunnel. As a result, the diffusion of the high-temperature air and toxic gas occurring from the a fire was delayed when the smoke barrier was installed in a medium length road tunnel compared to that when it was not installed. In addition, when the installation interval of a smoke barrier was 100m and the numerical analysis target was 100m, the diffusion of high-temperature air and toxic gas generated by the fire was delayed more than in the other cases, which was most suitable for tunnel users to evacuate.

• Fire Science and Engineering
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• v.31 no.6
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• pp.67-73
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• 2017

An aircraft maintenance hangar is a building that stores, maintains, and inspects expensive aircraft. The frequency of fire occurrence is low, but the resulting human and material damage can be very serious. Therefore, in this study, we conducted a qualitative analysis of the fire safety of the currently operating fire suppression systems for aircraft maintenance hangars using the Fault Tree method, and then performed a quantitative analysis using the failure rate data for the derived basic events and analyzed the importance of the minimal cut sets. As a result of the qualitative analysis by the minimal cut set, it was found that there were 14 accident paths that could be expanded to a large fire, due to the fire control failure of the aircraft hangar fire suppression system. The quantitative analysis revealed that, the probability of the fire expanding into a large one is $2.08{\times}E-05/day$. The analysis of the importance of the minimal cut set shows that four minimal cut sets, namely the fire detector and foam head action according to the zone and blocking of the foam by the aircraft wing and the fire plume, had the same likelihood of causing the fire to develop into a large one, viz. 24.95% each, which together forms the majority of the likelihood. It was confirmed for the first time by fault tree method that the fire suppression system of aircraft maintenance hangars is not suitable for fires under the aircraft wings and needs to be improved.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.182-193
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• 2000

Several metrics have been used in crash discrimination algorithms in order to have timely air bag deployment during all frontal crash modes. However, it is still challengine to have timely air bag deployment especially during the oblique, the pole and the underride crash mode. Therefore, in this paper a new crash discrimination algorithm was proposed, using the absolute value of the deceleration change multiplied by the velocity change as a metric, and processing the metric as a function of the velocity change. The new algorithm was applied for all frontal crash modes of a minivan and a sports utility vehicle, and it resulted in timely air bag deployment for all frontal crash modes including the oblique, the pole and the underride crash mode. Moreover, it was proposed that an accelerometer be installed at each side of the rails, rockers or pillars to assess the crash severity of each side and to deploy the frontal air bags at different time especially during an asymmetric crash such as an oblique and an offset crash. As an example, the deceleration pulses measured at the left and right B-pillar·rocker locations were processed through the new algorithm, and faster time-to-fires were obtained for the air bag at the struck side for the air bag at the other side.

• Tunnel and Underground Space
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• v.28 no.1
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• pp.38-58
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• 2018

The ventilation system plays a crucial role in underground mine safety. The main objective of the ventilation system is to supply sufficient air to dilute the contaminated air at working places and consequently provide tenable environment during the normal operation, while it also should be capable of controlling the fire propagation and facilitate rescue conditions in case of fire in mines. In this study, a smoke control fan was developed for the auxiliary ventilation as well as the fire smoke exhaust. It works as a free-standing auxiliary fan without tubing to dilute or exhaust the contaminated air from the working places. At the same time, it can be employed to extract the fire smoke. This paper aims to examine the smoke control efficiency of the fan when combined with the current ventilation system in mines. A series of the site experiments and numerical simulations were made to evaluate the fan performance in blind entry development sites. The tracer gas method with SF6 was applied to investigate the contaminant behavior at the study sites. The results of the site study at a large-opening limestone mine were compared with the CFD analysis results with respect to the airflow pattern and the gas concentration. This study shows that in blind development entry, the most polluted and risky place, the smoke fan can exhaust toxic gases or fire smoke effectively if it is properly combined with an additional common auxiliary fan. The venturi effect for smoke exhaust from the blind entry was also observed by the numerical analysis. The overall smoke control efficiency was found to be dependent on the fan location and operating method.

• Steel and Composite Structures
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• v.15 no.6
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• pp.679-703
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• 2013

This paper presents experimental investigations of the fundamental behavior of concrete filled steel tube (CFT) beam-columns under fire loading. A total of thirteen specimens were tested to determine the axial force-moment-curvature-temperature behavior of CFT beam-columns. The experimental approach involved the use of: (a) innovative heating and control equipment to apply thermal loading and (b) digital image correlation with close-range photogrammetry to measure the deformations (e.g., curvature) of the heated region. Each specimen was sequentially subjected to: (i) constant axial loading; (ii) thermal loading in the expected plastic hinge region following the ASTM E119 temperature-time T-t curve; and (iii) monotonically increasing flexural loading. The effects of various parameters on the strength and stiffness of CFT beam-columns were evaluated. The parameters considered were the steel tube width, width-tothickness ratio, concrete strength, maximum surface temperature of the steel tube, and the axial load level on the composite CFT section. The experimental results provide knowledge of the fundamental behavior of composite CFT beam-columns, and can be used to calibrate analytical models or macro finite element models developed for predicting behavior of CFT members and frames under fire loading.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1953-1958
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• 2012

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with such electric faults, specially short circuit faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30ms(KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problem, this paper proposes a prevention apparatus using the line voltage drop of neutral wire and some semiconductor switching devices. Some experimental tests of the proposed apparatus confirm the validity of the analytical results.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.2
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• pp.73-76
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• 2022

Most of ants seem to be beneficial, whereas some of them are annoying or harmful. Among harmful creatures red imported fire ants have been notorious for not only destroying farm plants and domestic animals but also biting and killing human beings. The red imported fire ants, Solenopsis invicta Buren and Solenopsis richiteri Forel, will feed on the buds and fruits of numerous crop plants. Large nests located in fields interfere with and damage equipment during cultivation and harvesting. They respond rapidly and aggressively to disturbances, and ant attacks inhibit field worker activities. A single fire can sting its target repeatedly. Young and newborn animals as well as humans are especially susceptible to the stings' venom. These pests can damage the environment by displacing native ant species and reducing food sources for wildlife. In Korea Solenopsis invicta Buren were found for the first time in Busan Gamman port in 2017. Then they were found in Incheon port, Pyongtaek port, North Daegu, Ansan in 2018 and Gwangyang in 2021. Once they invaded and occupied the terrestrial area, we have no proper solution to prevent them. I can assume that they have been successfully enlarging their colonies toward inland since they can move freely by flight. Therefore, I strongly suggest that we need to study ants in order not only to control harmful ants properly but also to preserve and use beneficial ants in this country.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.4
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• pp.461-467
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• 2015

119 Integrated Emergency Management System, 119 IEMS hereinafter, is specialized command and control system for fire H.Q., that supports effective response activity at Fire, Rescue, and First Aids; it covers the emergency call taking, dispatch command delivery and situation control after dispatch command. While the efficiency of emergency response activity of call-taker and dispatcher is directly linked to the capability of qualified response in protecting the life and properties at real-time emergency condition, there is not any similar simulator system that can be used for training purposes for newly allocated personnel or beginner of emergency call taking and dispatch activity - 119 IEMS in fire H.Q. is the operation system that cannot be shared with other purposes, and they're highly expensive ICT system and infrastructure to be used as training and education. 119 Integrated Emergency Management Simulator System, 119 IEMS Simulator, was developed to be utilized in low cost for the training of 119 emergency call taker and dispatcher, and it can be used in training of various types of disaster and emergency handling, spans to emergency call taking, dispatch command, and field report and situation control after dispatch command.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.5
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• pp.93-98
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• 2011

In this paper, we propose the surveillance and combat robot framework for remote monitoring and robot control on the smart phone, which is implemented with the fusion technology called RITS(Robot technology & Information Technology System). In our implemented system, the camera phone mounted on the robot generates signals to control the robot and sends images to the smart phone of the operator. Therefore, we can monitor the surrounding area of the robot with the smart phone. Besides the control of the movement of the robot, we can fire the weapons armed on the robot by sending the fire command. From experimental results, we can conclude that it's possible to control the robot and monitor the surrounding area of the robot and fire the weapons in real time in the region where the 3G(Generation) mobile communication is possible. In addition, we controlled the robot using the 2G mobile communication or wired phone when the robot is in the visual range.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.886-892
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• 2010

It is possible to use wireless communication any time in every place because of well-developed wireless networks and mobile devices. The AVL(Automatic Vehicle Location) system, therefore, has made practical use in situation control, distribution industry, home delivery service, and ITS(Intelligent Transportation System) area. In this paper, we design and implement an AVL system in order to use for fire fighting activities such as emergency rescue and relief. To do this, first, we investigate and analyze the existing researches and systems related to AVL system. In details, we develop an AVL server and clients to support stable communication each other using wireless networks. Using AVL system, calling cars find the position of accidents quickly and the fire defense headquarters control unforeseen accidents efficiently because the state of calling cars are confirmed in real time by their GPS data.