• 제목/요약/키워드: Fault tree

검색결과 447건 처리시간 0.026초

Fault-tree 확률계산을 위한 근사적 방법 (An approximate approach for Computing Fault-tree probabilities)

  • 이근희;이동형
    • 품질경영학회지
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    • 제18권2호
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    • pp.25-32
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    • 1990
  • This paper presents an approximate algorithm for computing Fault-tree probabilities. The method is essentially composed of three steps. In the first step, a Fault-tree is converted into a network form. In the second step, We change the network into a parallelized diagram. In the third step, the approximate fault-tree probability is calculated from the parallelized diagram. In this paper, in order to verify the method two hypothetical Fault-tree is used by examples. The results show that the method is very useful, even though it is an approximate technique, since it needs not to search the minimal cut sets and has the simple computing rontines.

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Electrical Fire Hazards Analysis of Electric Iron and Heater Using Fault Tree Analysis

  • Hong, Sung-Ho
    • International Journal of Safety
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    • 제7권1호
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    • pp.15-20
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    • 2008
  • The primary goal of this study is to analyze fire hazards of electric home appliances such as electric iron and electric heater using fault tree analysis(FTA). A fault tree(FT) is constructed and used to analyze fire hazards in electric home appliances. The fault tree is built from events that may occur in electric home appliances. The failure rate of basic events are derived from the value of experimental results and reference. And an algorithm analyzing fire in electric home appliances is suggested. We show how fault tree analysis, carried out by means of failure rate, is able to diagnose fire hazards of electric home appliances in a precise manner. We present numerical results such as fire probability of electric home appliances, importance measure, fire cause, etc. It can be helpful in preventing the fire hazards in electric home appliances.

A top-down iteration algorithm for Monte Carlo method for probability estimation of a fault tree with circular logic

  • Han, Sang Hoon
    • Nuclear Engineering and Technology
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    • 제50권6호
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    • pp.854-859
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    • 2018
  • Calculating minimal cut sets is a typical quantification method used to evaluate the top event probability for a fault tree. If minimal cut sets cannot be calculated or if the accuracy of the quantification result is in doubt, the Monte Carlo method can provide an alternative for fault tree quantification. The Monte Carlo method for fault tree quantification tends to take a long time because it repeats the calculation for a large number of samples. Herein, proposal is made to improve the quantification algorithm of a fault tree with circular logic. We developed a top-down iteration algorithm that combines the characteristics of the top-down approach and the iteration approach, thereby reducing the computation time of the Monte Carlo method.

스크루형 공기압축기의 고장진단 (Fault Diagnosis of Screw type Air Compressor)

  • 배용완
    • Journal of Advanced Marine Engineering and Technology
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    • 제28권7호
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    • pp.1092-1100
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    • 2004
  • This paper describes the application of fault tree technique to analyze of compressor failure. Fault tree analysis technique involves the decomposition of a system into the specific form of fault tree where certain basic events lead to a specified top event which signifies the total failure of the system. In this research. fault trees for failure analysis of screw type air compressor are made. This fault trees are used to obtain minimal cut sets from system failure and system failure rate for the top event occurrence can be calculated. It is Possible to estimate air compressor reliability by using constructed fault trees through compressor failure example. It is Proved that FTA is efficient to investigate the compressor failure modes and diagnose system.

Fault Tree 분석에 의한 상수도 가압장과 배수지의 경보시스템 구축 (Development of Alarm System Using Fault Tree Analysis for Pumping Station and Reservoir of Waterworks)

  • 안용포;송무근;이동익
    • 상하수도학회지
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    • 제25권6호
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    • pp.847-859
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    • 2011
  • This paper presents an alarm system for the integrated monitoring and control station of waterworks in Daegu City. An alarm system informs the operator or other responsible individuals about the abnormality in the process so that an appropriate action can be taken. In practice, operators receive far more false and nuisance alarms than valid and useful alarms. Too many false and nuisance alarms can distract the operator from operating the plant, and thus critical alarms may be ignored. This problem can lead to the point that the operator no longer trusts the alarms or even shuts down the whole monitoring system. This paper proposes an efficient method to reduce false and nuisance alarms by prioritizing every fault using the Fault Tree Analysis (FTA) technique. The effectiveness of the proposed method is evaluated with a set of computer simulation under various faulty conditions.

동적 Fault Tree 분석을 이용한 시스템 신뢰도 평가 (System Reliability Evaluation using Dynamic Fault Tree Analysis)

  • 변성일;이동익
    • 대한임베디드공학회논문지
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    • 제8권5호
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    • pp.243-248
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    • 2013
  • Reliability evaluation is important task in embedded system. It can avoid potential failures and manage the vulnerable components of embedded system effectively. Dynamic fault tree analysis is one of the reliability evaluation methods. It can represent dynamic characteristics of a system such as fault & error recovery, sequence-dependent failures. In this paper, the steering system, which is embedded system in vehicles, is represented using dynamic fault tree. We evaluate the steering system using approximation algorithm based on Simpson's rule. A set of simulation results shows that proposed method overcomes the low accuracy of classic approximation method without requiring no excessive calculation time of the Markov chain method.

Fault Tree를 이용한 신뢰성 분석 (Reliability Analysis Using Fault Tree)

  • 이창훈;박순달
    • 한국국방경영분석학회지
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    • 제6권1호
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    • pp.119-124
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    • 1980
  • An efficient algorithm which can be employed in obtaining the minimal cut sets of a fault tree containing repeated events is introduced. A sample fault tree illustrates this algorithm. Efficiency of an algorithm is defined as the ratio of the number of minimal cut sets to the number of cut sets determined by the algorithm. An efficiency of the proposed algorithm is compared with those of two existing algorithms : Fussell and Vesely's algorithm and Bengiamin et al. 's algorithm. The proposed algorithm is shown to be more efficient than the existing two algorithms.

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산업 안전시스템에 있어서 Fault Tree Analysis의 적용 (An Application of Fault Tree Analysis in Industrial Safety System)

  • 김진규
    • 산업경영시스템학회지
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    • 제13권21호
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    • pp.43-50
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    • 1990
  • Fault tree analysis(FTA) is available to the engineer for determining reliability of complex industrial safety system. Therefore quantitative aspects of FTA greatly multiply its power this paper proceeds of presenting the methodology of FTA, including an approach to constructing in fault tree. A working guide to the use of FTA for the purpose of cost/benefit determination in industrial safety system is given. Finally, an analytic method for uncertainty analysis of the top event of a complex system is described.

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시스템 신뢰도 평가를 위한 동적 결함 트리(Dynamic Fault Tree) 알고리듬 연구 (A Study on Reliability Evaluation Using Dynamic Fault Tree Algorithm)

  • 김진수;양성현;이기서
    • 한국통신학회논문지
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    • 제24권10A호
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    • pp.1546-1554
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    • 1999
  • 본 논문에서는 결함 및 마스크, 스위칭 기능을 포함한 결함에 대한 동적 구조를 갖는 결함 허용 시스템에 대하여 신뢰도 평가를 할 수 있는 동적 결함 트리 알고리듬(Dynamic Fault Tree Algorithm)을 제안한다. 본 알고리듬에서는 동적 특성을 표현할 수 있는 FDEP, CSP, SEQ, PAG 게이트 정의로부터 출발한다. 이러한 게이트의 정의는 시스템의 동적 특성을 만족시키기 위해 시스템의 상태증가를 유발하는 기존의 마코브 모델과 시스템의 정적 특성에 대해서만 평가 가능했던 결함 트리 모델에 대한 제약조건을 해결할 수 있었다. 본 논문에서는 제시한 알고리듬의 장점을 입증하기 위하여 동적 특성을 가지는 TMR(Triple Modular Redundancy) 시스템과 이중화 중복 시스템(Dual Duplex System)에 대해 기존의 알고리듬과 제시하는 알고리듬을 적용하여 신뢰성 평가를 수행한 후 이를 통해 제시하는 알고리듬이 동적 여분을 사용하는 시스템이나 순차 종속 고장들을 가지는 시스템, 결함과 오류의 복구 기술을 가지는 시스템들에 대해 우수함을 보여준다.

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객체지향 장치 모델링을 이용한 Fault Tree의 자동합성 (Automatic Synthesis of Fault Tree Using Object-oriented Unit Modeling)

  • 황규석;허보경
    • 한국가스학회지
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    • 제5권2호
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    • pp.1-8
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    • 2001
  • 공정의 위험성 평가를 위한 이상트리 작성은 많은 시간과 인력을 요하는 작업으로 대규모 화학공장에 적용하기가 매우 힘들다. 본 연구에서는 화학공정의 이상트리 합성을 위해 장치에서 발생할 수 있는 공정변수의 이탈 및 장치이상에 대한 원인-결과 관계를 나타내는데 필요한 객체지향 지식기반의 프레임워크를 제안하였다. 이상에 대한 원인을 탐색하기 위하여 장치의 객체지향 모델링과 장치간의 연결관계를 이용하여 이탈을 전파하고 이를 통해 이상트리를 합성하였다. 제안된 방법론을 질산 냉각 공정에 적용하여 그 유효성을 검증하였다.

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