• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2001년도 춘계학술발표논문집
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• pp.461-464
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• 2001

역할기반 접근제어(RBAC)는 역할(Role)과 역할계층(Role hierarchy)을 통해 사용자 및 접근권한 관리를 효율적으로 수행할 수 있도록 해준다. 그러나 시스템에 수많은 사용자, 역할, 권한이 존재하는 경우 한사람의 보안 관리자가 이들을 모두 관리하는 컷은 불가능하므로 역할을 관리하는 관리역할을 두어 시스템을 효율적으로 관리할 수 있는 방법(ARBAC)이 제안되었다. ARBAC는 URA(User Role Assignment), PRA(Permission Role Assignment), RRA(Role Role Assignment)로 구성되어있다. 본 논문에서는 URA99 모델을 기반으로 사용자-역할 관리를 위하여 관리도구를 구현한다. 구현된 관리도구는 오라클의 저장 프로시저를 사용하고 자바를 기반으로 한 EJB 컴포넌트로 구현한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.198-200
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• 2005

This paper illustrates the pragram features of reliability evaluation on operation mode (operational planning and operating) of power system. The eighty eight relative reports and papers with seventeen kinds of reliability programs were Investigated in this paper. Two programs, PRA and ASSESS, were focused on the operation mode reliability evaluation program and the comparions of the two program features are introduced.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.265-270
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• 2003

Though the probability of tunnel fire accident is very low, but critical fatalities are expected when it occurred. In this study the effect of critical safety parameters on tunnel fire accident are examined using probabilistic technique. Fire detection time, smoke spread velocity, passenger escape velocity, flash-over time, and emergency service arrival time are considered. In order to estimate the uncertainties of input parameters Monte Carlo simulation are used, and fatalities for each assumed accident scenarios are obtained as results. For the efficiency of iterative calculation PRA(Probabilistic Risk Analysis) code is developed in this study. As a result fire detection have large effect.

• Nuclear Engineering and Technology
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• 제19권4호
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• pp.279-291
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• 1987

현재 원자력발전소의 확률론적 위해도 평가에 사용되는 사상 수목이나 고장수목 기법은 부품이나 계통의 이원적상태와 정적 묘사에 근거하고 있다 이 기법이 대부분의 안전해석에는 적합하지만, 요사이 점차 중요관심사가 되고 있는 발전소의 이용률 측정이나 기술 사양서 평가 같은 문제를 정확하게 다루기 위해서는 마코프 신뢰도 분석과 같은 보다 진보된 기법이 필요하다. 이 논문은 가압경수로의 원자로 보호계통을 위한 마코프 신뢰도 모델을 기술하고 기술사양서의 두 검사 절차를 분석한 결과를 제시한다.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.380-386
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• 2017

Fennovoima's nuclear power plant, Hanhikivi 1, $Pyh{\ddot{a}}joki$, Finland, is currently in design phase, and its construction is scheduled to begin in 2018 and electricity production in 2024. The objective of this paper is to produce a preliminary list of safety-significant external event combinations including preliminary probability estimates, to be used in the probabilistic risk assessment of Hanhikivi 1 plant. Starting from the list of relevant single events, the relevant event combinations are identified based on seasonal variation, preconditions related to different events, and dependencies (fundamental and cascade type) between events. Using this method yields 30 relevant event combinations of two events for the Hanhikivi site. The preliminary probability of each combination is evaluated, and event combinations with extremely low probability are excluded from further analysis. Event combinations of three or more events are identified by adding possible events to the remaining combinations of two events. Finally, 10 relevant combinations of two events and three relevant combinations of three events remain. The results shall be considered preliminary and will be updated after evaluating more detailed effects of different events on plant safety.

• 품질경영학회지
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• 제19권2호
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• pp.96-107
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• 1991

At the design stage of a plant, the plausible causes and pathways of release of hazardous materials are not clearly known. Thus there exist large amount of uncertainties on the consequences resulting from the operation of a fusion plant. In order to better handle such uncertain circumstances, we utilize the Probabilistic Risk Assessment(PRA) for the safety analyses on fusion power plant. In this paper, we concentrate on the tritium release accident. We develop a simple model that describes the process and flow of tritium, by which we figure out the locations of tritium inventory and their vulnerability. We construct event tree models that lead to various levels of tritium release from abnormal initiating events. Branch parameters on the event tree are assessed from the fault tree analysis. Based on the event tree models we construct influence diagram models which are more useful for the parameter updating and analysis. We briefly discuss the parameter updating scheme, and finally develop the methodology to obtain the predictive distribution of consequences resulting from the operating a fusion power plant. We also discuss the way to utilize the results of testing on sub-systems to reduce the uncertain ties on over all system.

• Journal of Information Technology Applications and Management
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• 제16권3호
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• pp.59-71
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• 2009

Hazard analysis identifies probability to hazard occurrence and its potential impact on business processes operated in organizations. This paper illustrates a quantitative approach of hazard analysis of information systems by measuring the degree of hazard to information systems using probabilistic risk analysis and activity based costing technique. Specifically the research model projects probability of occurrence by PRA and economic loss by ABC under each identified hazard. To verify the model, each computerized subsystem which is called a business process and hazards occurred on information systems are gathered through one private organization. The loss impact of a hazard occurrence is produced by multiplying probability by the economic loss.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2002년도 추계학술발표회
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• pp.163-175
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• 2002

가상현실 기법(virtual reality technologies)를 해양안전사고 가시화 시스템 개발에 적용하기 위한 개발론에 대해서 기술하였다. ‘목포해심’ 재결서 700여가지 사건에 대한 분류표와 수령화 표를 작성하여 질적 데이터를 양적 데이터로 변환하였다. 개발론에 대한 검토결과, 과거 10년 간의 해양사고 사건사례를 압축하여 저차원 데이터를 획득하기 위해서는 다변량해석기법(multivariate analysis)을 적용해야하고, 위기관리를 종합적으로 수행하기 위해서는 기존에 제시되고 있는 PRA, QRA, SPE 등의 기법 중 적합한 것을 적용할 필요가 있으며, 통계 데이터의 가시화를 위해서는 MATLAB의 Simulink 와 VR Toolkit을 이용하면 가능함을 분석할 수 있었다.

• 조명전기설비학회논문지
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• 제28권4호
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• pp.70-79
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• 2014

In this paper, I propose a method for detection of look-alike offenders by using hidden face information. For extraction of moving objects, PRA matching is used to extract moving components, and brightness changes can be dealt with by an adaptive threshold adjusting in the proposed method. Moving objects extracted in the territory of the face region is extracted using the complexion, facial area, eyes, nose, mouth. The extracted information detected by the presence of these characteristics were likely to help judge a person. Results of the extracted face makes the recognition rate of possible murderers 90% so the usefulness of the proposed method was confirmed.

• Earthquakes and Structures
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• 제9권3호
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• pp.563-576
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• 2015

Over the past few decades, seismic retrofitting of structural systems has been significantly improved by the adoption of various methods such as FRP composite wraps, base isolation systems, and passive/active damper control systems. In parallel with this trend, probabilistic risk assessment (PRA) for structural and nonstructural components has become necessary for risk mitigation and the achievement of reliable designs in performance-based earthquake engineering. The primary objective of the present study was to evaluate the effect on piping fragility at T-joints due to seismic retrofitting of structural systems with passive energy-dissipation devices (i.e., linear viscous dampers). Three mid-rise building types were considered: without any seismic retrofitting; with distributed damper systems; with optimal placement of dampers. The results showed that the probability of piping system failure was considerably reduced in a Multi Degree of Freedom (MDOF) building retrofitted with optimal passive damper systems at lower floor levels. This effect of damper systems on piping fragility became insignificant as the floor level increased.