• Title/Summary/Keyword: Fire Damaged

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A Study for the Fire Analysis and Igniting Cause of Freezing Protection Heating Cables (동파방지열선 화재 흔적분석과 발화원인 연구)

  • Lee, Jung Il;Ha, Kag Cheon
    • Journal of the Korean Society of Safety
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    • v.33 no.3
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    • pp.15-20
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    • 2018
  • There have been a number of major fatal fire accidents in Korea recently. The number of fires in 2017 were 44,178, which is not only increasing number of fires but also increasing in casualties. Particularly, the fire at Jecheon Sports Center, which suffered many casualties, is expected to have a huge impact. The cause of the fire has not been determined yet, but heat waves on the ceiling have also been pointed out. As such, the copper heating waves, which are used as a preventive measure against damage of pipes due to freezing of pipes, etc., always have a fire hazard. To determine the possibility of a flame-resistant heated fire, a positive electric cable product was used to artificially ignite and analyze the results. In case of a short circuit, the external covering of the positive electric cable is damaged, but not short circuit unless the heating material surrounding the wire is damaged. Due to the characteristics of heating cable for preventing copper waves, the chances of insulation becoming more severe due to moisture and temperature changes are higher than normal wires. If the internal heating system is carbonized by insulating deterioration without damage to the outer coating, it is likely to cause trekking, to form a winding loop in the heating materials, and to cause short circuit in the heated materials. For the positive temperature line, if the middle is shorted, the current continues to flow to the short circuit unless the breaker disconnects. Consequently, a heated fire that does not cut off the power immediately may leave multiple marks or cuts.

Comparison a Forest Fire Spread variation according to weather condition change (기후조건 변화에 따른 산불확산 변화 비교)

  • Lee, Si-Young;Park, Houng-Sek
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.490-494
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    • 2008
  • We simulated a forest fire which was occurred in Yangyang area on 2005 and compared a results between two different weather conditions(real weather condition and mean weather condition since 1968) using FARSITE, which is a forest fire spread simulator for preventing and predicting fire in USDA. And, we researched a problem in the transition for introducing, so we serve the basic method for prevention and attacking fire. In the result, severe weather condition on 2005 effected a forest fire behavior. The rate of spread under real weather condition was about 4 times faster than mean weather condition. Damaged area was about 10 time than mean weather condition. Therefore, Climate change will make a more sever fire season. As we will encounter to need for accurate prediction in near future, it will be necessary to predict a forest fire linked with future wether and fuel condition.

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Detection of Wildfire-Damaged Areas Using Kompsat-3 Image: A Case of the 2019 Unbong Mountain Fire in Busan, South Korea

  • Lee, Soo-Jin;Lee, Yang-Won
    • Korean Journal of Remote Sensing
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    • v.36 no.1
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    • pp.29-39
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    • 2020
  • Forest fire is a critical disaster that causes massive destruction of forest ecosystem and economic loss. Hence, accurate estimation of the burned area is important for evaluation of the degree of damage and for preparing baseline data for recovery. Since most of the area size damaged by wildfires in Korea is less than 1 ha, it is necessary to use satellite or drone images with a resolution of less than 10m for detecting the damage area. This paper aims to detect wildfire-damaged area from a Kompsat-3 image using the indices such as NDVI (normalized difference vegetation index) and FBI (fire burn index) and to examine the classification characteristics according to the methods such as Otsu thresholding and ISODATA(iterative self-organizing data analysis technique). To mitigate the salt-and-pepper phenomenon of the pixel-based classification, a gaussian filter was applied to the images of NDVI and FBI. Otsu thresholding and ISODATA could distinguish the burned forest from normal forest appropriately, and the salt-and-pepper phenomenon at the boundaries of burned forest was reduced by the gaussian filter. The result from ISODATA with gaussian filter using NDVI was closest to the official record of damage area (56.9 ha) published by the Korea Forest Service. Unlike Otsu thresholding for binary classification,since the ISODATA categorizes the images into multiple classes such as(1)severely burned area, (2) moderately burned area, (3) mixture of burned and unburned areas, and (4) unburned area, the characteristics of the boundaries consisting of burned and normal forests can be better expressed. It is expected that our approach can be utilized for the high-resolution images obtained from other satellites and drones.

A Study on the Damaged Pattern of Dryvit by External Flame (외부화염에 의한 드라이비트의 소손패턴 연구)

  • Park, Young Ju;Hong, Yi Pyo;Lee, Hae Pyeong
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.40-47
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    • 2015
  • In this study, temperature characteristics and fire damage form were analyzed to investigate flame spreading form and fire probability from ignition sources subject to drivit component materials which is finishing material in architecture. Ignition sources were limited to a gas torch and exterior panel board fire, and the size of the sample was manufacture in 30 cm length ${\times}$ 50 cm height ${\times}$ 5cm thickness size. Marble (inner wall) + 3 mm drivit (outer wall), marble (inner wall) + 4 mm plaster stone (outer wall), sandwich panel + 3 mm driver bit (outer wall), sandwich panel + 3 mm driver bit + insulation (outer wall), and gypsum board (inner wall) + 3 mm drivit (outer wall) were prepared for the sample. As result of the research for temperature characteristics, large temperature difference by each material was shown in $218^{\circ}C{\sim}995^{\circ}C$ at 30 seconds and $501^{\circ}C{\sim}1078^{\circ}C$ at 300 seconds. Especially when the inner wall was a plaster board, lowest temperature of $501^{\circ}C$ was shown at 300 seconds and marble inner wall showed the following lowest temperature of $900^{\circ}C$. Temperature rising over $1000^{\circ}C$ was shown in other materials. Regarding fire damage form, drivit or gypsum board outer wall parts exposed to fire showed combustion and carbonization to show calcination(breaking phenomenon) and influence of heat exposure was higher as calcination became more severe.

Comparative Analysis of Forest Fire Danger Rating on Forest Characteristics of Thinning Area and Non-thinning Area on Forest Fire Burnt Area (산불적지에서 숲 가꾸기 실행 유무와 산불위험성 비교 분석)

  • Lee, Si-Young;Lee, Myung-Woog;Yeom, Chan-Ho;Kwon, Chun-Geun;Lee, Hae-Pyeong
    • Fire Science and Engineering
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    • v.23 no.4
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    • pp.32-39
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    • 2009
  • In this study, 18 plots were selected for particular investigation on Gangneung area and Samcheok area and Uljin area, where forest fire was occurred after thinning in 2007. After selection, a relationship between a damage of forest fire and thinning were compared and analyzed. Many factor such as a damaged species, a thinning or non-thinning, a direction of forest fire head, DBH, a height of tree, a mortality of tree, a leeward scorching ratio, a crown damage ratio, a forest tree standing crop density, a crown base height, a leaving of thinning slash, a location of plot (GPS), elevation, an aspect of slope, an angle of slope, and a topography were measured. Therefore, we analyzed a relationship with forest fire. In the result of this analysis, it was founded that the leeward scorching ratio was 24.7% on thinning area whereas 60.2% on non-thinning area. Subsequently, leeward scorching ratio on thinning area was increased by about 35.5% more than on non-thinning area. In the result of analysis about tree species, a forest of pine tree was more damaged than forest of oak tree. The mortality of tree was increased by about 41.4% on non-thinning area. When stands were close to thinning slashes, these were more damaged by 10${\sim}$20% than other stands for increasing of amount of a combustion material. Especially, as potential of re-ignition increased for more cumulated thinning slash, it will be more important to require a method for a periodical removing or practical utilization of slash.

Performance of RC Beams Strengthened with FRP-Aluminum Composite Hollow Beam Under the Fire (RC보에 대한 FRP-Aluminum 유공복합보의 보강성능에 관한 연구)

  • Lee, Jae-Ik;Choi, Yeol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.2
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    • pp.153-160
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    • 2010
  • The widespread deterioration of concrete structures has required the development of new and innovative materials and technologies for strengthening and repair. Recently Fiber reinforced polymer(FRP) composites have received widespread attention as materials for the strengthening and repair of the deteriorated concrete structures. This paper presents the results of Fire-performance of RC beams strengthened with FRP-Aluminum composit hollow beams. Test results show that the higher-damaged FRP strengthened RC beams are more vulnerable to the fire and decrease the effect of FRP strenthening.

Analysis of Forest Fire Damage Using LiDAR Data and SPOT-4 Satellite Images (LiDAR 자료 및 SPOT-4 위성영상을 활용한 산불피해 분석)

  • Song, Yeong Sun;Sohn, Hong Gyoo;Lee, Seok Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3D
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    • pp.527-534
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    • 2006
  • This study estimated the forest damage of Kangwon-Do fire disaster occurred April 2005. For the estimation, the delineation of fire damaged area was performed using SPOT-4 satellite image and DSM (Digital surface model)/DTM (Digital Terrain Model) was generated by airborne and ground LiDAR data to calculate forests height. The damaged amount of money was calculated in forest area using stand volume formula, combining the canopy height from forest height model and digital stock map. The total forest damage amounted to 3.9 billion won.