• Nuclear Engineering and Technology
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• 제43권3호
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• pp.271-278
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• 2011

When performing fire PSA in a nuclear power plant, an event mapping method, using an internal event PSA model, is widely used to reduce the resources used by fire PSA model development. Feasible initiating events and component failure events due to fire are identified to transform the fault tree (FT) for an internal event PSA into one for a fire PSA using the event mapping method. A surrogate event or damage term method is used to condition the FT of the internal PSA. The surrogate event or the damage term plays the role of flagging whether the system/component in a fire compartment is damaged or not, depending on the fire being initiated from a specified compartment. These methods usually require explicit states of all compartments to be modeled in a fire area. Fire event scenarios, when using explicit identification, such as surrogate or damage terms, have two problems: (1) there is no consideration of multiple fire propagation beyond a single propagation to an adjacent compartment, and (2) there is no consideration of simultaneous fire propagations in which an initiating fire event is propagated to multiple paths simultaneously. The present paper suggests a fire propagation equation to identify all possible fire event scenarios for an explicitly treated fire event scenario in the fire PSA. Also, a method for separating fire events was developed to make all fire events a set of mutually exclusive events, which can facilitate arithmetic summation in fire risk quantification. A simple example is given to confirm the applicability of the present method for a $2{\times}3$ rectangular fire area. Also, a feasible asymptotic approach is discussed to reduce the computational burden for fire risk quantification.

• 한국컴퓨터정보학회논문지
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• 제14권4호
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• pp.87-99
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• 2009

SOA를 도입하는 하향식 (top-down) 방법은 온톨로지를 기반으로 서비스를 분석하고 설계하는 서비스 모델링 단계를 핵심으로 봄으로써 SOA의 장점을 가장 잘 반영할 수 있는 방법으로 권장되고 있다. 그러나 대부분의 기업들은 하향식 방법이 최상이라는 것을 알면서도 기업 이윤 창출에 단기적인 효과가 드러나지 않고 도입 초기에 개발시간과 비용이 증대되므로 이를 꺼리게 된다. 특히 잘 정의된 컴포넌트 시스템을 이미 사용하고 있는 경우에 더욱 그러하다. 따라서 본 논문에서는 기존의 잘 정의된 컴포넌트시스템을 최대한 이용할 수 있는 상향식 (bottom-up) 서비스식별 방법을 제안한다. GUI는 직접 사용자의 입력을 받아 들여 이벤트를 발생시킨다는 점에 착안하여 이벤트의 경로를 연결하면 비즈니스 프로세스에 근사시킬 수 있다. 따라서 컴포넌트와 상호작용하는 GUI의 이벤트 수를 기준으로 핵심 GUI를 선정하고 핵심 GUI로부터 연결되는 이벤트 경로를 대상으로 기존의 순차패턴 마이닝 알고리즘을 변형하여 사용자의 서비스 사용 패턴을 추출한다. 실험결과 추출된 이벤트 패턴에 응집도를 적용하여 다양한 크기의 비즈니스 서비스를 식별할 수 있음을 보였다.

• Journal of Plant Biotechnology
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• 제47권4호
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• pp.309-315
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• 2020

Advances in biotechnology have led to progress in crop genetic engineering to improve agricultural productivity. The use of genetically modified (GM) crops has increased, as have consumers' and regulators' concerns about the safety of GM crops to human health, and ecological biodiversity. As such, the identification of GM crops is a critical issue for developers and distributors, and their labeling is mandatory. Multiplex polymerase chain reaction (PCR) has been developed and its use validated for the detection and identification of GM crops in quarantine. Herein, we established a simultaneous detection method to identify four GM maize events. Event-specific primers were designed between the junction region of transgene and genome of four GM maize lines, namely 5307, DAS-40278-9, MON87460, and MON87427. To verify the efficiency and accuracy of the multiplex PCR we used specificity analysis, limit of detection evaluation, and mixed certified reference materials identification. The multiplex PCR method was applied to analyze 29 living, modified maize volunteers collected in South Korea in 2018 and 2019. We performed multiplex PCR analysis to identify events and confirmed the result by simplex PCR using each event-specific primer. As a result, rather than detecting each event individually, the simultaneous detection PCR method enabled the rapid analysis of 29 GM maize volunteers. Thus, the novel multiplex PCR method is applicable for living modified organism volunteer identification.

• 한국안전학회지
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• 제32권3호
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• pp.160-171
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• 2017

US national research laboratories developed the first Vital Area Identification (VAI) method for the physical protection of nuclear power plants that is based on Event Tree Analysis (ETA) and Fault Tree Analysis (FTA) techniques in 1970s. Then, Korea Atomic Energy Research Institute proposed advanced VAI method that takes advantage of fire and flooding Probabilistic Safety Assessment (PSA) results. In this study, in order to minimize the burden and difficulty of VAI, (1) a set of streamlined VAI rules were developed, and (2) this set of rules was applied to PSA fault tree and event tree at the initial stage of VAI process. This new rule-based VAI method is explained, and its efficiency and correctness are demonstrated throughout this paper. This new rule-based VAI method drastically reduces problem size by (1) performing PSA event tree simplification by applying VAI rules to the PSA event tree, (2) calculating preliminary prevention sets with event tree headings, (3) converting the shortest preliminary prevention set into a sabotage fault tree, and (4) performing usual VAI procedure. Since this new rule-based VAI method drastically reduces VAI problem size, it provides very quick and economical VAI procedure. In spite of an extremely reduced sabotage fault tree, this method generates identical vital areas to those by traditional VAI method. It is strongly recommended that this new rule-based VAI method be applied to the physical protection of nuclear power plants and other complex safety-critical systems such as chemical and military systems.

• 정보처리학회논문지D
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• 제14D권2호
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• pp.211-216
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• 2007

RFID(Radio Frequency Identification)는 라디오 신호에 따라 반응하는 태그(Tag)를 이용하여 해당 사물을 인식하는 방법이다. RFID 환경에서는 태그로부터 EPC를 읽어오는데 이 EPC만을 가지고는 해당 물품이 무엇인지만을 알 수 있고 부가적인 상세 정보를 얻기에는 제한적이다. 이 때문에 RFID를 효과적으로 응용하여 사용할 수 있도록 여러 업체나 기관에서 RFID 시스템을 연구하였다. 그러나 여전히 기존의 RFID 시스템은 해당 어플리케이션의 비즈니스 이벤트를 처리하기 위해 RFID에 대한 다양한 지식과 통신 방법 등을 모두 이해하여야 하는 복잡함과 어플리이션 개발을 지원하는 측면에서 부족함이 있다. 본 논문에서는 RFID 어플리케이션에서 편리하게 이용할 수 있는 비즈니스 이벤트를 정의하였다. 그리고 이러한 비즈니스 이벤트를 생성하여 어플리케이션에 전달할 수 있는 비즈니스 이벤트 프레임워크(Business Event Framework, BEF)를 제시하였다.

• Journal of Computing Science and Engineering
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• 제9권2호
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• pp.73-82
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• 2015

Understanding how the topic evolves is an important and challenging task. A topic usually consists of multiple related events, and the accurate identification of event evolution relationship plays an important role in topic evolution analysis. Existing research has used the traditional vector space model to represent the event, which cannot be used to accurately compute the semantic similarity between events. This has led to poor performance in identifying event evolution relationship. This paper suggests constructing a semantic aspect-based vector space model to represent the event: First, use hierarchical Dirichlet process to mine the semantic aspects. Then, construct a semantic aspect-based vector space model according to these aspects. Finally, represent each event as a point and measure the semantic relatedness between events in the space. According to our evaluation experiments, the performance of our proposed technique is promising and significantly outperforms the baseline methods.

• 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.

• 한국정보보호학회:학술대회논문집
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• 한국정보보호학회 1995년도 종합학술발표회논문집
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• pp.115-125
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• 1995

본 논문에서는 컴퓨터 시스템에서 침입 감지 시스템을 설계함에 있어서 사용될 수 있는 새로운 방법인 Event Sequence Tracking 방법을 제안하였다. Event Sequence Tracking 방법에서는 컴퓨터 시스템의 공격방법을 크게 두가지로 분류한다. 첫번째는 일련의 시스템 명령어를 이용한 공격방법이고 두번째는 침입자 자신이 만들었거나 다른 사람으로부터 얻은 프로그램을 이용하는 방법이다. 첫번째 공격방법에 대한 감지방법은 시스템을 공격할 때 사용한 일련의 시스템 명령어들을 감사 데이타를 분석하여 찾아내고 이 결과를 기존에 알려진 공격 시나리오들과 비교하여 침입자를 찾아내는 방식이다. 두번째 공격방법에 대한 감지 방법은 보안 관리자가 정해놓은, 시스템에서 일반 사용자가 할 수 없는 행위에 관한 보안 정책에 따라 Key-Event 데이타 베이스를 만들고 여기에 해당하는 event의 집합을 감사 데이타에서 찾아내는 방법이다. Event Sequence Tracking 방법은 Rule-based Penetration Identification 방법의 일종으로서 시스템의 공격방법을 분류하여 컴퓨터 시스템에의 침입을 효과적으로 감지할 수 있다는 것과 rule-base의 생성과 갱신을 함에 있어서 보다 간단하게 할 수 있다는 장점을 갖는다.

• Smart Structures and Systems
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• 제16권1호
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• pp.163-181
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• 2015

This research investigates the structural health monitoring of nonlinear structures after a major seismic event. It considers the identification of flag-shaped or pinched hysteresis behavior in response to structures as a more general case of a normal hysteresis curve without pinching. The method is based on the overall least squares methods and the log likelihood ratio test. In particular, the structural response is divided into different loading and unloading sub-half cycles. The overall least squares analysis is first implemented to obtain the minimum residual mean square estimates of structural parameters for each sub-half cycle with the number of segments assumed. The log likelihood ratio test is used to assess the likelihood of these nonlinear segments being true representations in the presence of noise and model error. The resulting regression coefficients for identified segmented regression models are finally used to obtain stiffness, yielding deformation and energy dissipation parameters. The performance of the method is illustrated using a single degree of freedom system and a suite of 20 earthquake records. RMS noise of 5%, 10%, 15% and 20% is added to the response data to assess the robustness of the identification routine. The proposed method is computationally efficient and accurate in identifying the damage parameters within 10% average of the known values even with 20% added noise. The method requires no user input and could thus be automated and performed in real-time for each sub-half cycle, with results available effectively immediately after an event as well as during an event, if required.

• 디지털콘텐츠학회 논문지
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• 제9권2호
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• pp.165-175
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• 2008

현재 소프트웨어 개발을 위한 방법론은 객체지향에서 컴포넌트지향으로 컴포넌트지향에서 서비스지향 발전되어 오고 있다. 컴포넌트지향 개발 방법과 서비스지향 개발 방법들은 객체지향 UML 모델을 기반으로 분석되어지므로 효율적인 객체지향 분석 방법이 필요하다. 따라서 본 논문에서는 UML 기반의 클래스 식별 및 유스케이스 모델링이 개발자의 직관과 경험에 의존하는 문제점을 보완하여 입력 데이터-처리 프로세스-출력 데이터를 사용한이벤트 기반의 유스케이스 및 클래스 분석 가이드라인과 분석 프로세스를 제안 한다.