• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권10호
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• pp.3965-3982
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• 2015

Event detection is one of the key issues in many wireless sensor network (WSN) applications. The uncertainties that are derived from the instability of sensor node, measurement noise and incomplete sampling would influence the performance of event detection to a large degree. Many of the present researches described the sensor readings with crisp values, which cannot adequately handle the uncertainties inhered in the imprecise sensor readings. In this paper, a fault-tolerant event detection algorithm is proposed based on Dempster-Shafer (D-S) theory (also called evidence theory). Instead of crisp values, all possible states of the event are represented by the Basic Probability Assignment (BPA) functions, with which the output of each sensor node are characterized as weighted evidences. The combination rule was subsequently applied on each sensor node to fuse the evidences gathered from the neighboring nodes to make the final decision on whether the event occurs. Simulation results show that even 20% nodes are faulty, the accuracy of the proposed algorithm is around 80% for event region detection. Moreover, 97% of the error readings have been corrected, and an improved detection capability at the boundary of the event region is gained by 75%. The proposed algorithm can enhance the detection accuracy of the event region even in high error-rate environment, which reflects good reliability and robustness. The proposed algorithm is also applicable to boundary detection as it performs well at the boundary of the event.

• 기록학연구
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• 제51호
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• pp.175-208
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• 2017

본 연구는 특정 사건을 중심으로 기록을 수집 관리하는 '사건 아카이브'의 개념을 정립하고 사건 아카이브 구축 시 고려사항을 제시하는 것을 목적으로 한다. 이를 위해 먼저 사건 아카이브의 정의를 내린 후, 사건 아카이브의 특성을 살펴보기 위해 기존의 민간 기록물 아카이빙 연구방법인 공동체 아카이브와 로컬리티 도큐멘테이션과의 차이점을 파악하였다. 또한 사건 아카이브는 인물, 공간, 시간으로 구성되며, 다른 연구방법과 비교하여 시간적 요소를 특히 중요하게 여기기 때문에 본 연구에서는 시간을 축으로 나머지 요소를 접목한 팽이 모형을 제시하였다. 마지막으로, 본 연구는 사건 아카이브 구축 시 세 가지 고려사항을 제시하였다. 첫째, 사건 발생 시기에 따라 사건 아카이브의 구축 방법을 다르게 제시하였다. 둘째, 사건 아카이브의 세 요소인 인물, 공간, 시간에 따라 기록 수집 및 관리 영역을 제안하였다. 셋째, 오픈 아카이브로 발전하기 위해 디지털 아카이브를 지향할 것을 제안하였다.

• Journal of Electrical Engineering and Technology
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• 제1권2호
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• pp.170-176
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• 2006

This paper proposes a topological locating algorithm to determine the location of the power quality event source. This algorithm makes use of the information on the topology of the monitored network and on the direction of PQ events. As a result, the bus incidence matrix is modified using monitor location and the direction matrix is constructed. With this information, the algorithm determines the suspected locations of the PQ events. To reduce suspicious areas, it utilizes event cause and related equipment. In case of line fault event, it calculates the distance from the monitor to the location of event source. The overall algorithm is applied to the IEEE test feeder and accurately identifies the event source location.

• Communications for Statistical Applications and Methods
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• 제15권5호
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• pp.727-735
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• 2008

Consider a clinical trial in which the main end-point is survival. Suppose after the start of the study an intermediate event occurs which may be influenced by a covariate(or treatment). In many clinical studies the occurrence of an intermediate event may change the survival distribution. This investigation develops two-stage model which, in the first stage, models the effect of covariate on the intermediate event and models the relationship between survival time and covariate as well as the intermediate event. In this paper, the two-stage model is presented in order to model intermediate event and a test based on this model is also provided. A numerical simulations are carried out to evaluate its overall significance level.

• 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.

• 대한가정학회지
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• 제44권5호
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• pp.59-68
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• 2006

This study investigated preschoolers' emotionality, emotional knowledge, event knowledge, and interpersonal problem solving strategies according to their sex and age, and the relationships among them. Subjects were 116 preschoolers (73 boys and 43 girls; 68 four- and 48 five-year-olds). Results showed that girls were higher in negative emotionality (sadness) than boys. Also, 5-year-old children were higher in emotional knowledge, event knowledge, and forceful problem solving strategies than 4-year-olds. Furthermore, children's event knowledge was positively related to their relevant problem solving strategies, while children's event knowledge was negatively related to their forceful problem solving strategies. These findings provide a preliminary evidence that children's event knowledge may predict their interpersonal problem solving strategies.

• 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.

• 한국산업융합학회 논문집
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• 제9권3호
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• pp.191-197
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• 2006

Prepare need in each branch for a large scale event. especially prepare for transportation problem is very important. most research for until at now parking prepare according city management however, parking prepare for large event is a necessity which it will parking characteristic. accordingly this research is conducted study for parking prepare subject of large event. this study result, vehicle demand for parking by stadium have many but vehicle demand for parking off stadium have few. accordingly large parking supply is ineffective. shuttle bus service in principal position of city is effective. study result showed that it included 85% parking at 6~7hour before large event start time. accordingly disposition time of parking manager is desirable 6~7hour before large event start time.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1962-1967
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• 2008

A event recorder system stores a train speed and the related information for train operation in real time. Using those information, we can analysis the train operation and the reason of train accident. Currently the event recorder only manipulate the data related the train operation mechanically and electrically. In this paper we propose the event recorder to record the voice communication between the manager in the control center and train operator. By recording the voice communication in the high speed train, the correctness of analysis of train accident can be increased. The system architecture of the event recorder with voice recording is studied and interface between other equipment is proposed. And the software architecture of new event recorder is developed. We study the method of converting analog voice signal into digital data and compressing method. Also the architecture of memory to store the compressed voice data and regeneration of original analog voice are studied.