• Title/Summary/Keyword: Engineering criticality analysis

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Research to define facility type, project consideration and restriction when conceiving civil-military sharing facilities, by applying the Delphi technique (델파이기법을 활용한 민군간 공용 시설유형 및 고려요소 판단 연구)

  • Gong, Keum Rok;Kang, Han-Seung;Ahn, Jin-Ho;Park, Young Jun
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.2
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    • pp.57-66
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    • 2018
  • When developing projects to build facilities to be shared by both military bases and surrounding communities, strategies are needed to achieve two objectives: 1) minimize missteps and opposition from local communities in the process of developing and implementing such projects, and 2) promote cost-benefit optimization and user-satisfaction. With aim of promoting co-operation and co-existence between military bases and adjust communities, this research proposes esthetical factors to be considered in conceiving civil-military sharing facilities. It seeks experts' opinions on the development of civil-military sharing facilities, and examines critical factors (economic feasibility, security, and satisfaction, etc.) for project development as well as building types suitable for shared-use between military bases and local residents. It then establishes a method to prioritize facility-type and narrow down design factors (considerations and restrictions) in project development by applying quantitative analysis. The methodological approach of the research employs the Delphi survey method to quantitatively analyze qualitative information drawn from experts' opinions. At the first round of the survey, facility types, items for consideration and restrictions are drawn, and then at the second round of the survey, criticality of each item is analyzed. Finally, it reaches a conclusion on suitability of facility types for civil-military sharing facilities, and selects project considerations and restrictions when developing this kind of project.

A Fault Detection Method for Solenoid Valves in Urban Railway Braking Systems Using Temperature-Effect-Compensated Electric Signals (도시철도차량 제동장치의 솔레노이드 밸브에 대한 전류기반 고장진단기법 개발)

  • Seo, Boseong;Lee, Guesuk;Jo, Soo-Ho;Oh, Hyunseok;Youn, Byeng D.
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.9
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    • pp.835-842
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    • 2016
  • In Korea, urban railway cars are typically maintained using the strategy of predictive maintenance. In an effort to overcome the limitations of the existing strategy, there is increased interest in adopting the condition-based maintenance strategy. In this study, a novel method is proposed to detect faults in the solenoid valves of the braking system in urban railway vehicles. We determined the key component (i.e., solenoid valve) that leads to braking system faults through the analysis of failure modes, effects, and criticality. Then, an equivalent circuit model was developed with the compensation of the temperature effect on solenoid coils. Finally, we presented how to detect faults with the equivalent circuit model and current signal measurements. To demonstrate the performance of the proposed method, we conducted a case study using real solenoid valves taken from urban railway vehicles. In summary, it was shown that the proposed method can be effective to detect faults in solenoid valves. We anticipate the outcome from this study can help secure the safety and reliability of urban railway vehicles.