• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2007년도 정기학술대회
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• pp.155-162
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• 2007

In this study, we explore the polysemy of da3 through the ontological conceptual structure found in SUMO. First, we divide several different senses for da3, clustering physical event senses and metaphorical event senses. In here, we only focus on physical event senses of da3. From the physical event senses of da3, we divide them into two main categories: 1) hit and 2) pump. We then use SUMO ontological concepts to identify these physical senses. Finally, we can observe the common patterns of the "hit" sense group and the "pump" sense group for da3.

• Journal of Communications and Networks
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• 제14권6호
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• pp.597-605
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• 2012

With the smart grid coming near, wide-area supervisory control and data acquisition (SCADA) becomes more and more important. However, traditional SCADA systems are not suitable for the openness and distribution requirements of smart grid. Distributed SCADA services should be openly composable and secure. Event-driven methodology makes service collaborations more real-time and flexible because of the space, time and control decoupling of event producer and consumer, which gives us an appropriate foundation. Our SCADA services are constructed and integrated based on distributed events in this paper. Unfortunately, an event-driven SCADA service does not know who consumes its events, and consumers do not know who produces the events either. In this environment, a SCADA service cannot directly control access because of anonymous and multicast interactions. In this paper, a distributed security framework is proposed to protect not only service operations but also data contents in smart grid environments. Finally, a security implementation scheme is given for SCADA services.

• 한국안전학회지
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• 제23권5호
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• pp.35-42
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• 2008

There are many efforts toward the development of next generation gas safety management systems to improve the assurance, availability, and efficiency of the extant systems. Among them, the application of ubiquitous technology, such as RFID and USN, to the system is regarded as a promising approach for enabling such an innovation. Recently the ubiquitous technology became much affordable and available than before thanks to the reduced production cost and wide proliferation of the ubiquitous devices. In this paper, we analyze the core requirements for the next generation gas safety management systems based on the ubiquitous technology, and present an architectural design of a middleware to facilitate the realization of the system. We formally define an event model and present how to specify various situations related to gas safety management using the proposed event model.

• Journal of Power Electronics
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• 제17권6호
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• pp.1650-1657
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• 2017

In this study, the distributed secondary voltage control of islanded microgrids with multi-agent consensus algorithm is investigated. As an alternative to a time-triggered approach, an event-triggered scheme is proposed to reduce the communication load among inverter-based distributed generators (DGs). The proposed aperiodic control scheme reduced unnecessary utilization of limited network bandwidth without degrading control performance. By properly establishing a distributed triggering condition in DG local controller, each inverter is only required to send voltage information when its own event occurs. The compensation of voltage amplitude deviation can be realized, and redundant data exchange related to fixed high sampling rate can be avoided. Therefore, an efficient use of communication infrastructure can be realized, particularly when the system is operating in steady state. The effectiveness of the proposed scheme is verified by simulations on a microgrid test system.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1992년도 제2회 정기총회 및 추계학술 발표회 발표논문 초록
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• pp.5-5
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• 1992

The DEVS(discrete event system specification) formalism describes a discrete event system in a hierarchical, modular form. DEVSIM++ is C++ based general purpose DEVS abstract simulator which can simulate systems to be modeled by the DEVS formalism in a sequential environment. We implement P-DEVSIM++ which is a parallel version of DEVSIM++. In P-DEVSIM++, the external and internal event of models can be processed in parallel. To process in parallel, we introduce a hierarchical distributed simulation technique and some optimistic distributed simulation techniques. But in our algorithm, the rollback of a model is localized itself in contrast to the Time Warp approach. To evaluate its performance, we simulate a single bus multiprocessor architecture system with an external common memory. Simulation result shows that significant speedup is made possible with our algorithm in a parallel environment.

• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.186-190
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• 2023

There are unimaginable possibilities ahead of us. As a result, it is difficult to predict the future, but the prediction itself is not meaningless. This is because it can have the flexibility to cope with contingencies by predicting various possibilities. This study was conducted to explore extreme events (X-event) in the Korean population sector. To this end, in-depth interviews were conducted with experts from the Korea Army Research Center for Future & Innovation and the Army College, and based on this, significant research results were derived that population problems such as population decline and aging can affect various fields such as economy. With this study, we hope that discussions on extreme events (X-event) that can occur in our society will be further activated.

• 대한전기학회논문지:전력기술부문A
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• 제53권10호
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• pp.565-572
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• 2004

This paper proposes an expert system which can enhance the accuracy of real-time bus reconfiguration strategy by adopting local minimum tree search method and minimize the spreading effect of the fault by considering totally the operating condition when a main transformer fault occurs in the automated substation. The local minimum tree search method to expand the best-first search method. This method has an advantage which can improve the performance of solution within the limits of the real-time condition. The inference strategy proposed expert system consists of two stages. The first stage determines the switching candidate set by searching possible switching candidates starting from the main transformer or busbar related to the event. And, second stage determines the rational real-time bus reconfiguration strategy based on heuristic rules for the obtained switching candidate set. Also, this paper studies the generalized distribution substation modelling using graph theory and a substation database is designed based on the study result. The inference engine of the expert system and the substation database is implemented in MFC function of Visual C++. Finally, the performance and effectiveness of the proposed expert system is verified by comparing the best-first search solution and local minimum tree search solution based on diversity event simulations for typical distribution substation.

• 한국전자거래학회지
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• 제13권3호
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• pp.1-20
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• 2008

오늘날 컴퓨팅 환경은 과거에 비해 매우 분산되어 있으며 다양한 시스템과 연결되고 통합되는 동적인 구성을 필요로 한다. 대부분의 기업들은 이를 위해 객체지향적인 메시지 송수신 체계인 MOM(Message Oriented Middleware) 시스템을 사용하여 원격의 시스템과의 통신채널을 구성하고 송수신 정보를 XML 메시지로 주고받고 있다. 그러나 대부분의 MOM 시스템들은 송수신 메시지로 사용되는 XML을 처리함에 있어 XML 메시지의 동적 변환 및 라우팅을 지원하지 않아 기업 시스템의 효율성과 유지보수성을 저하 시키고 있다. 이에 본 논문에서는 가장 널리 사용되고 있는 MOM 시스템인 JMS를 기반으로 동적 XML 메시지 변환 및 라우팅을 지원하기 위한 룰 기반의 라우팅 시스템인 RMRS(Rule-based Message Routing System)를 제안한다. RMRS는 룰 기반 이벤트 처리를 위해 사용되는 ECA(Event- Condition-Action)룰을 확장하여 분산 시스템 구현 시에 빈번하게 발생하는 라우팅 처리를 XML 변환과 함께 동적으로 처리할 수 있도록 한다. 이것은 내부적으로 메시지가 라우팅 되기 전에 수신한 메시지의 성격에 따라 XML 메시지의 변환을 수행할 수 있도록 설계되어 있어, 이를 바탕으로 MOM 시스템을 구축할 경우, XML 메시지의 동적 변환 및 라우팅을 효과적으로 구현할 수 있다.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.484-484
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• 2001

The sophistication of current software applications results in the increasing cost fur software development time. The component-based software development framework is proposed to overcome the difficulty and time-consuming requirements by modularity and reusability. As is the general software case, a component-based simulation framework encourages the reusability of the real system model based on the modularity of the applied simulation methodology. This paper presents a component-based simulation environment that is based on the DEVS/COM run-time infrastructure. The DEVS (Discrete Event System Specification) formalism provides a formal modeling and simulation framework for the generic dynamic systems [1] and Microsoft's COM (Component Object Model) is one of the strongest competitor fur the component standard. The reusability by the DEVS/COM simulation environment saves model development time remarkably and component technology make simulator itself to be a subparts of real application.

• 인터넷정보학회논문지
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• 제15권6호
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• pp.65-75
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• 2014

본 논문의 주안점은 다양한 매스 미디어에 나타난 이벤트(event) 정보를 자동으로 인식하고, 이를 시간 및 장소 축으로 시각화함으로써 특정 이벤트의 시간의 흐름에 따른 장소 이동의 추이를 분석하는 데에 있다. 특히 사용자가 직접 작성한 소셜 미디어에 기반하여 이벤트를 추출하고 그들 간의 연속성 분석을 통해 해당 이벤트의 변화 방향성과 사회적 영향을 가늠할 수 있다. 연속성 이벤트의 특성을 규명하기 위해 2년간의 뉴스 기사 및 트윗(tweet)을 수집하여 관련 도메인 선정을 위한 전수조사를 수행하였다. 수행 결과, '질병'과 '여가'도메인을 선정, 본 논문에서 제안한 시각화 방법을 적용한 사례 연구를 통해 시간 및 장소 관점에서의 시각화를 통한 추이 분석의 효용성과 제안된 방법의 유용성을 검증하였다. 특히 단순 사실기반의 연속성 시각과 결과와 사용자의 관심도가 반영된 소셜 미디어에 기반한 연속성 시각화 결과를 비교한 결과, 같은 시기의 이벤트들이라 하더라도 사회적으로 미치는 파장이 큰 장소 이동의 흐름을 파악할 수 있음을 보였다.