• Title/Summary/Keyword: GROUND FIRE

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Comparison of Biomass by Forest Fire Type and Recovery at Samcheuk-si, Gangwon-do, Korea (산불 유형별 식생회복정도에 따른 현존생물량 비교)

  • Lim, Seok-Hwa;Kim, Jung-Sup;Shin, Jin-Ho;Bang, Je-Yong;Yang, Keum-Chul
    • Korean Journal of Environment and Ecology
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    • v.26 no.4
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    • pp.528-536
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    • 2012
  • This study has compared the different types of forest fires(unburned, crown fire, ground fire) and the degree of vegetation recovery at Samcheuk-si, Gangwon-do by assessing the biomass and net primary production from July 2007 through July 2010. The research showed that the average biomass of unburned site(Un), crown fire site(C-1), crown fire site(C-3), ground fire site(G-2) were $181.20{\pm}5.39$, $62.04{\pm}4.38$, $131.09{\pm}14.38$, $63.39{\pm}2.72ton{\cdot}ha^{-1}$, respectively. And the research showed that the average net primary production of unburned site(Un), crown fire site(C-1), crown fire site(C-3), ground fire site(G-2) were $4.17{\pm}0.56$, $3.27{\pm}1.56$, $11.51{\pm}0.53$, $2.10{\pm}0.31ton{\cdot}ha^{-1}{\cdot}yr^{-1}$, respectively. Quercus mongolica $DH_{10}$(Diameter at the 10cm tree height) growth rate at each plot was compared to the crown fire site(C-1) in the annual average $1.21{\pm}0.55mm{\cdot}yr^{-1}$ at the speed of the fastest growth follows; showed crown fire site(C-3), ground fire site(G-2), unburned site(Un) appeared in the order. And that showed the growth rate of height was highest in the $15.43{\pm}4.57cm{\cdot}yr^{-1}$ at crown fire site(C-3), then the crown fire site(C-1), and ground fire site(G-2), and lowest in the unburned site(Un).

Evaluation of Heat Transfer Characteristics due to a Fire of a Train Standing at Under-Ground Station (지하역사에 정차한 열차의 화재에 따른 역사 내 열유동 특성 평가)

  • Lee, Kwang-Seob;Shin, Kwang-Bok;Kim, Dong-Hyun;Lee, Eun-Kyu;Kim, Jae-Hwang;Ryu, Bong-Jo
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1619-1625
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    • 2007
  • This paper deals with the heat transfer characteristics due to a fire of train standing at under-ground station. In order to analyze the fluid characteristics at under-ground station, the governing equation was assumed to be steady-state, incompressible and turbulent fluid model. The commercial Fluent ver. 6.0 was used to solve the above numerical problem. Through the numerical analysis, fluid path-line, temperature distribution and $CO_2$ density distribution are demonstrated for three kinds of cases. As a conclusion of the study, a scenario for operation of ventilation fan in a fire is proposed.

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An Effective Threat Evaluation Algorithm for Multiple Ground Targets in Multi-target and Multi-weapon Environments

  • Yoon, Moonhyung;Park, Junho;Yi, Jeonghoon
    • International Journal of Contents
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    • v.15 no.1
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    • pp.32-38
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    • 2019
  • In an environment where a large number of weapons are operated compared to a large number of ground targets, it is important to monitor and manage the targets to set up a fire plan, and through their multilateral analysis, to equip them with a priority order process for targets having a high threat level through the quantitative calculation of the threat level. Existing studies consider the anti-aircraft and anti-ship targets only, hence, it is impossible to apply the existing algorithm to ground weapon system development. Therefore, we proposed an effective threat evaluation algorithm for multiple ground targets in multi-target and multi-weapon environments. Our algorithm optimizes to multiple ground targets by use of unique ground target features such as proximity degree, sorts of weapons and protected assets, target types, relative importance of the weapons and protected assets, etc. Therefore, it is possible to maximize an engagement effect by deducing an effective threat evaluation model by considering the characteristics of ground targets comprehensively. We carried out performance evaluation and verification through simulations and visualizations, and confirmed high utility and effect of our algorithm.

A System IC for Controlling the Fire Prevention (화재방지제어 시스템 IC)

  • Kim, Byung-Cheul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.4
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    • pp.737-746
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    • 2009
  • In this study, we have developed one chip system IC for preventing the overload, detecting an abnormal conditions, and controlling the fire prevention in the intelligent home appliances. For the purpose, a circuit detectable an electric leak for preventing an electric shock, and a circuit detectable arc that has effect directly on the fire are designed. The circuits designed on every block are verified by comparing simulation with bread-boarding using a standard transistors. The system IC is fabricated by using 34 V 2 metal $1.5{\mu}m$ bipolar transistor process from evaluation results. The electrical performances of IC application circuits and the system IC equipped on PCB board are evaluated. It is confirmed that the system IC is well operated for arc and ground fault(GF) signal.

Rotational Drive-Versus-Quality and Video Compression-Versus-Delay Analysis for Multi-Channel Video Streaming System on Ground Combat Vehicles (지상 전투 차량을 위한 다채널 영상 스트리밍 시스템의 회전 구동 대비 품질과 압축 대비 지연 분석)

  • Yun, Jihyeok;Cho, Younggeol;Chang, HyeMin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.1
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    • pp.31-40
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    • 2021
  • The multi-channel video streaming system is an essential device for future ground combat vehicles. For the system, the application of digital interfaces is required instead of the direct analog method to support selectable multiple channels. However, due to the characteristics of the digital interfaces that require en/decoding and signal conversion, the system should support the ability to adapt to quality and delay requirements depending on how video data is utilized. To support addressed issue, this study designs and emulates the multi-channel compressed-video streaming system of ground combat vehicle's fire control system based on commercial standards. Using the system, this study analyzes the quality of video according to the rotational speed of the acquisition device and Glass-to-Glass (G2G) delay between video acquisition and display devices according to video compression rates. Through these experiments and analysis, this paper presents the design direction of the system having scalability on the latest technology while providing high-quality video data streaming flexibly.

A Study on the Reliability Improvement Plan on Electric Leakage & Ground Fault of Low-voltage Electrical Line (저압전로의 누전.지락에 대한 신뢰성향상 방안에 관한 연구)

  • Kang, Kyung-Won;Yoon, Myung-O;Gu, Seon-Hwan;Song, Young-Joo
    • Fire Science and Engineering
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    • v.25 no.6
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    • pp.136-145
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    • 2011
  • One of a large proportion among the causes of fire is electrical factors, and of fire by electric factors, the accident which accounted for over certain percentage is electric leakage and ground fault. In order to reduce the electric leakage and ground fault, the technical guidelines on the protection of ground fault in the low-voltage electrical line (KECG 1091-2011) was amended for reflecting recent international standard, IEC 60364-4-41, and new conservation methods, which improved the reliability by recovering the facility's all-time use operation and breakdown defect, was on the rise. Accordingly, in this paper, after grasping the fire's status for last 10 years and analyzing the risk of electrical fires, and as a way to improve the electric leakage and ground fault accident which accounted for more than certain percentage, the revision of KECG 1091-2011 will be reviewed. And then, after applying to the preventive conservation methods in order to enhance the protection reliability of electric leakage and ground fault detection, the problems at issue routine inspection scheme and durable years scheme in time-scheduled conservation method are listed, along with suggestion of the problem-solving scheme, and the leakage current integrated monitoring systems and digital electric leakage devices by status monitor conservation method will be proposed.

Optimal Time-sequential Fire Support Strategies

  • O, Myeong-Ho
    • Journal of Korean Institute of Industrial Engineers
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    • v.1 no.1
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    • pp.79-86
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    • 1975
  • The optimal time-sequential distribution of supporting fire against enemy ground units in combat against attacking friendly units is studied. Lanchester type models of warfare are combined with optimal control theory in this investigation. The optimal time-sequential fire-support policy is characterized for a specific problem. Although complete details for the determination of the optimal policy are not given, it is conjectured, on the basis of the theorems which were proved, that for this problem the optimal policy is to always concentrate all supporting fire on the same enemy unit until supporting fire must be lifted.

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A Study on Analysis of ELB Characteristics (누전차단기의 특성해석에 관한 연구)

  • 김은배
    • Fire Science and Engineering
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    • v.2 no.1
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    • pp.21-28
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    • 1988
  • This paper deals with the optimal use of the ELB (Electric Leakage circuit Breaks) for the protection of low voltage distribution system. Since the ELB is recently used together for grounding fault while only the ground resistance was used in the past, the analysis of ELB characteristics is indispensible. By the quantitative analysis and the setting of limit the ground resistance and the ELB is derived and then the optimal use of the ELB is expected to contribute to the system protection.

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