• Title/Summary/Keyword: 누설위험도

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An Efficient Dynamic Workload Balancing Strategy Design of the Wireless Reading/Management System for the Corrosion Monitoring of Underground Structures (지하 구조물 부식 감시를 위한 무선 검침/관리 시스템 설계)

  • Kwan, Yong-Kwang
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.7
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    • pp.95-102
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    • 2014
  • There are a variety of structures below the surface are buried. In particular, if It is experiencing problems in the city gas pipe or electrical wire, our safety would be greatly jeopardized. Therefore, the underground structures which encounter a variety of pollutants are highly sensitive to corrosion. So if you are not identify the degree of corrosion, it can lead to large accidents such as gas leakage. Until now, person visit directly every underground structure to measure and record manually, but This approach requires a lot of human and material resources and the continuity of management. Therefore, the research to find out the risk factors quickly via the continuous management is needed, and in this paper the structures management systems in the vehicle being moved by combining ICT underground structures for state information wirelessly collects and analyzes system is proposed.

A Study on the safety measures for the protection of hydrogen cooling system of generator (수소를 냉각매체로 하는 발전기 안전대책에 관한 연구)

  • Lee Choon-Ha;Yuk Hyun-Dai
    • Journal of the Korean Institute of Gas
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    • v.8 no.4 s.25
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    • pp.55-61
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    • 2004
  • This paper provided a counter measures against the troubles and accidents that are likely to take place in the power plant using hydrogen gas as a coolant for the cooling system of the generator. Because of the extremely wide flammability limits of hydrogen in comparison to the other flammable gases, the safety measures against the hydrogen accidents is very important to ensure the normal operation of electric-power facility. This study's purpose was a presentation of standard model of safety management of hydrogen equipments in the coal firing power plant such as following items: 1) providing the technical prevention manual of the hydrogen explosions and hydrogen fires occurring in the cooling system of power generator; 2) the selection of explosion-proof equipments in terms of the risk level of operating environment; 3) the establishment of regulations and counter measures, such as the incorporation of gas leakage alarm device, for preventing the accidents from arising, 4) the establishment of safety management system to ensure the normal operation of the power plant.

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A Numerical Study on the Design of Water Mist Lance for Fire Suppression in Container (컨테이너 내부 화재진압을 위한 물분무창 설계에 관한 수치적 연구)

  • Han, Sang-goo;Choi, Jae-hyuk;Lee, Won-Ju
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.7
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    • pp.941-947
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    • 2017
  • Increasing marine transportation of dangerous goods using containers causes fire accidents on ships due to leakage of dangerous materials. In IMO (MSC.93), all vessels that are to be loaded five or more containers on weather deck area after 1 January 2016 are required to have a fire extinguishing system called Water Mist Lance (WML) on board. In this study, numerical analysis is performed to design WML with optimal edge radius of curvature using LS-DYNA. The analysis results for the three models with 10 mm, 15 mm and 20 mm lengths of the edge part showed that the only model with 15 mm length penetrated the wall of the container and did not cause damage to the edge of the WML. In the future, based on the results of this study, we will make a WML of prototype and conduct a performance test. And we will continue to improve the problems.

The Eire Risk Assessment in Compressed Natural Gas Buses & Gas Station (CNG 버스 및 충전소의 화재 위험도 평가)

  • Ko, Jae-Sun;Kim, Hyo
    • Fire Science and Engineering
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    • v.18 no.2
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    • pp.57-67
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    • 2004
  • The results of the risk assessing on general buses, consisting mainly of diesel-fueled buses, show that the frequency of the instantaneous release is 1.4${\times}$10$^{-3}$ /bus/year, from which the probability of the formation of fireball as a sub event becomes 1.7${\times}$104, and show that the leakage from the CNG-fueled buses is 0.002 event/year. Also, the frequency of gradual release due to a crack is estimated at 3.7${\times}$10$^{-3}$ /buses/year, and a subsequent probability at which this could lead to a jet flame as a sub event is 1.2${\times}$10$^{-3}$ This corresponds to 0.04event/year for the CNG-fueled buses. Dividing all the fired casualties by the running distance of diesel-fueled buses, the risk is 0.091 fire fatalities per 100-million miles. And the total fire risk fur CNG buses is approximately 0.17 per 100-million miles of travel. This means that CNG buses is twice or more dangerous than diesel buses. After all CNG buses are more susceptible to the major fires. In the aspect of the reliability of this study, generic models and the failure data used in assessing the risks of CNG buses are appropriate. However, more accurate physics-based models and databases should be supplemented with this study to provide the better results.

Comparison of Code Generation Tools from Formal Specification of Security Function (정형명세 보안기능의 코드생성 도구 비교)

  • 유희준;김일곤;최진영;김상호;노병규
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04a
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    • pp.829-831
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    • 2002
  • 최근 들어 보안에 대한 관심이 높아지고 있으며, 많은 보안 관련 프로그램이 사용되고 있는 상황이다. 하지만 안전성을 예측하기 어려운 보안 기능을 완벽하게 구현하기 위해서 현재의 테스팅 방법론만으로는 완전성을 보장할 수 없으므로 보다 안전한 보안 기능을 구현하기 위해서 정형명세 방법은 반드시 필요하다. 또한 실제로 시스템들이 개발되는 과정에 있어서 설계될 당시와는 달리 결함을 가질 수 있다. 시스템에 대한 명세가 정확하다 하더라도 개발자인 사람의 개입으로 인해서 개발하는 도중에 명세와 다른 결과를 초래하여 결함이 발생할 수 있다. 이러한 결함은 개발자나 사용자에 의해 쉽게 발견되기 어렵다. 만일 보안 시스템이 알져지지 않은 결함이 있다면 비밀 정보가 쉽게 누설될 수 있다는 큰 문제가 발생할 수 있다. 통신망을 사용하는 인구의 확대와 더불어 다양한 형태의 통신 서비스가 제공됨에 따라 시스템의 특성이 복잡해지고 불법적인 자료 접근의 위험도 많이 노출되고 있다. 따라서 명확한 정형명세 보안기능으로부터 자동 코드 생성은 반드시 필요하다. 본 논문에서는 여러 정형 도구를 사용해서 보안기능에 대한 정형명세를 작성한 후에 소스코드 생성한 후, 정형명세를 이용하여 설계 및 구현한 프로그램에 대한 명세와 소스코드간 일치성 검토 방법을 개발하여, 정형명세를 통해 생성된 보안기능 소스코드의 보안성 측면과 성능적 측면의 Teade-Off 분석하는 것이다. 논문에서는 인증 관련 보안 기능인 S/KRY에 대해서 4개(STATEMATE MAGMUM, Rational Rose 98, SPEAR, VDM-SL)의 정형도구를 사용하여 명세 후, 소스 코드를 생성하여 생성된 각 코드에 대하여 비교하였으며, 현재 상용화 되어있는 Bellcore 의 S/KEY 시스템과의 비교를 수행하였다. 분석에서는 제품의 효율성뿐만 아니라 보안성을 중요하게 생각하였으며, 앞으로 보안 관련 소프트웨어 개발에 사용될 수 있는 도구들이 가이드 라인에 대한 정보를 제공한다.

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The Investigation of Accidental Case for LNG Terminal (LNG 생산기지의 사고사례 조사)

  • Ma, Y.W.;Lee, S.R.;Yoon, K.B.
    • Journal of the Korean Institute of Gas
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    • v.10 no.4 s.33
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    • pp.47-51
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    • 2006
  • Safety issues for LNG(Liquified Natural Gas) terminal or LNG tank involve various concerns such as production/transportation at cryogenic temperature of $-160^{\circ}C$, large volume of handling, flammability and explosion risk. Hence, in designing an LNG terminal rigid safety criteria and mandatory requirements are unavoidable. Since known cases of LNG related accident are very few, careful study and root cause analysis of them are very important and provide precious information to increase safety level of the LNG terminal. In this paper most key accident cases were gathered and analysed to understand fundamental safety issues of LNG terminal to prevent further accident.

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A thermal stability testing and analysis for a surge protector installed in residential distribution board (주택용 분전반에 설치되는 서지보호기의 열적 안전성 시험 및 분석)

  • Kim, Ju-Chul;Park, Jang-Bum;Ki, Che-Ouk
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.339-341
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    • 2009
  • Surge Protective Device(SPD) is installed by increasing information and communication equipments and home network equipments by individual home, and the amount of SPD used is increasing by revision industry regulations and strengthening equipotential grounding system. Parts of SPD installed in residential distribution board has ZnO varistor, voltage constraint type devices, but it is exposed to Temporary Overvoltage Characteristic. This thesis analyzes products through Thermal Stability test for SPD for general house and suggests the better method. As results of analysis, Gas Discharge Tube(GDT) to cut off from a leakage current and more than two kinds of safety devices to protect Thermal Runaway were needed.

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Guideline for Field Partial Discharge measurement of Underground Transmission Level XLPE Cable (지중송전 XLPE케이블 활선상태 PD 측정기술 향상을 위한 가이드라인 제시)

  • Park, Jin-Woo;Choi, Kyung-Kyu;Lee, Joen-Seon
    • Proceedings of the KIEE Conference
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    • 2008.10a
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    • pp.141-142
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    • 2008
  • 국내 지중송전선로는 주로 XLPE케이블과 OF케이블로 구성된다. 1971년 154kV급 OF 케이블이 최초로 한전에 의해 상용운전에 들어간 후 XLPE 케이블 지중선로가 1983년부터 병용운전 되고 있으며 OF케이블의 경우 절연유의 사용으로 인한 화재의 위험과 환경오염 문제 등으로 인하여 점진적으로 XLPE케이블로 대체되는 추세에 있다. 하지만 내전압 시험, 절연저항이나 누설전류 측정, $tan{\delta}$ 측정 등으로 진단이 가능했던 OF케이블과는 달리 XLPE케이블의 경우 종래의 시험을 통한 진단은 한계가 있고 부분방전을 통한 진단이 가장 효율적인 진단방법으로 제시되어 국내외 XLPE케이블의 진단을 위해 운영되고 있으며 보다 정확한 PD측정을 위한 연구가 계속 진행되고 있다. 지난 10년여간의 국내외 연구결과 XLPE케이블에 대한 PD 측정기술의 정확성은 상당히 향상되었고 그 결과물로서 수많은 폭정 장비와 기법이 개발되어 오늘날 널리 보급되고 있다. 하지만 여전히 측정된 Data에 대한 해석은 일부 전문가들에게 조차 복잡하고 어려운 일로 남아 있다. 자칫 그릇된 해석은 향후 큰 사고로 이어질 수 있으므로 선로 운영자의 입장에서는 측정결과의 신뢰성에 민감할 수밖에 없다.

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The Accident Hazard and Properties of the Leakage Current on the Electrical Insulation by Pollution (전기 절연물의 오염에 따른 누설전류 특성 및 사고위험성 연구)

  • Kim, Young-Seok;Shong, Kil-Mok;Jung, Jin-Su;Jung, Jong-Wook;Kim, Sun-Gu
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.463-467
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    • 2007
  • It is necessary to study the prevention and the management of electrical facilities because the electrical fault took place at the dust occurrence area due to environmental pollution. In particular, the dust accumulates easily on insulation material which is exposed an external long time. The leakage current brings out electrical fault after all. Also, it is need to variation of material and shape to repress a leakage current on electrical material. In this paper, we measured a leakage current on electrical material of facilities by dust, and in experiments the prevention to electrical fault was studied.

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Development of an Inspection Box for a Guard Lamp with an Automatic Switch (자동점멸식 보안등 점검함 개발)

  • Jung, Jong-Wook;Jung, Jin-Soo;Kim, Sun-Gu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.10
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    • pp.34-40
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    • 2008
  • In this paper, a device for safety inspection of a guard lamp with an automatic switch which has been recently employed in some local autonomous entities was developed. It is technically enhanced by installing a separate inspection box down below, which allows the inspectors can measure the leakage current, the sound function of the electric leakage breaker(ELB), the insulation resistance and the grounding resistance, on the ground. This inspection box makes the inspectors free from the electric shock by being designed to minimize the potential direct contact with the energized terminals. The deliverables of this paper are expected to contribute to carry out the inspection for the guard lamps safely and effectively.