• The Transactions of the Korea Information Processing Society
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• v.7 no.5
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• pp.1426-1433
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• 2000

As distributed computing systems become popular, many modeling techniques and methods have been developed in specify the specification formally and verify the distributed/concurrent sytems. In spite of importance of communication in distributed object-oriented systems, specifying of communication method generally has not been emphasized in the design phase. One reason is due to the system designer misunderstanding, that is, a specification needs to be independent on the implementation. However, since defining communication pattern indistributed object-oriented systems is more serious than the required message passing method in the design phase. specifying the communication pattern is necessary instead of postponing until the implementation. In this paper, two formal specification techniques, temporal logic method and Petri nets method, for the communication in distributed systems are discussed. One is based on the temporal logic, which specifies the different patterns of primitive predicates. This method enable to define the underlying mechanism which can be interpreted as constraints. The Petri net method helps to specify the dynamic behavior of communicational patterns using the properties of Petri nets.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.653-656
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• 2000

We consider, in this paper, a UML-based design support system for real-time systems. However, the UML does not include any notion for verification of timing constraints. We presents transformation algorithms, as a function of the support system, of UML descriptions into Petri nets and Interval Temporal Logic models, which are very powerful for the verification. This paper shows also transformation example for simple elevator system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.485-491
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• 1998

이산사건 시스템은 시간의 이산순간에 상태변화가 발생하는 시스템으로서 공정제어, Robotics, 교통시스템, Flexible Manufacturing System, 통신등 많은 분야의 시스템이 이산사건 시스템들이지만 아직도 포괄적이고 융통성 있는 제어이론이 연구되지 않았다. 본 연구는 특히 Real-Time Temporal Logic Framework(RTTL)에서 비결정적으로 발생되어지는 확정적인 사건들로써 유발되어지는 비결정적 이산사건 시스템의 모델링 방법을 제시하였다. 이 방법을 두 개의 machine들로 구성된 Flexible Manufacturing System(FMS)에 적용하여 설명하였다. 이 방법은 복잡한 이산사건 시스템의 모델링을 모듈화하여 간편하게 표현 할 수 있는 우수한 특성을 가지고 있다.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2292-2294
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• 2003

본 논문은 crisp discrete event system(CDES)에서 다룰 수 없는 특성을 가지는 의료진단이나 교통제어와 같이 애매하거나 불확실한 판단 그리고 관련성이 모호한 판단의 근거들에 의해 결정되어지는 사건들로 이루어진 fuzzy discrete event system(FDES)의 모델링 방법에 대하여 연구하였다. CDES는 모델링 방법이 많이 연구되어져 왔으나, FDES는 발생되어지는 사건들의 정성적인 특성과 적용되어지는 경우가 드문 이유로 거의 연구되어져 있지 않다. 본 논문에서는 temporal logic에 fuzzy개념을 도입하여 fuzzy DES의 새로운 모델링 방법을 제시하고 의료진단 시스템에 적용하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.148-150
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• 2004

부정행위 탐지는 개별 사용자의 행동 기록과 그 사용자와 유사한 프로필을 갖고 있는 사용자들의 행동 기록을 바탕으로 행동 패턴 혹은 행동 규칙을 찾아내, 이 패턴/규칙과의 비교를 통해 현재 행위가 부정한 것인지를 결정하는 방법을 주로 사용한다. 그러나, 특정 사용자의 행위패턴이 급격하게 바뀌는 경우, 과거의 기록을 바탕으로 생성된 패턴의 유효성은 보장받을 수 없다. 더구나 기존 기록과 상이한 행위에 대한 새로운 패턴이 생성되기 위해서는 계속해서 그런 행위가 쌓여야만 하고, 그 쌓이는 양은 기존 패턴의 견고성에 비례된다. 또한 동일 사용자에게 털러 패턴을 적용시키는 방법 역시 패턴간의 충돌이 일어나는 등의 한계가 존재한다. 본 논문에서는 시간 논리(Temporal Logic)를 적용하여, 과거의 패턴의 유효성을 검증하고 신규패턴을 빠르게 찾아내는 방법을 제안하고자 한다.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.1
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• pp.1-6
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• 1999

This paper is on the analysis for the real-time software requirement. This method can be used for TNPN(Timed Numerical Peri Net) as a easy communication means with real-users. It is based on the RTTL(Real Time Temporal Logic) for correctness the system. TNPN is used to represent a behavior specification language, the validity of specified behaviors in TNPN is expressed in RTTL, and analyzed through the teachability graph. Thus, the requirement between user and system is satisfied Using the example of shared track, the validity of the property of real-time(safetiness, responsiveness, liveness, priority) is verified. Also this framework if given to connection with a object, natually.

• 한국가스학회:학술대회논문집
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• 1999.09a
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• pp.244-249
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• 1999

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.4
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• pp.301-306
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• 2007

The people information is distributed in various forms such as database, web page, text, and so on, where the world wide web is one of the main sources of publicly-available people information. It has a characteristic that the information on people is intrinsically temporal. Therefore, the reconstruction of the information is needed for an individual or a company to use it efficiently. In order to maintain or manage the temporal people information, it must distinguish the variable information from invariable information of people. In this paper, we propose a method that constructs an ontology based on events to manage the variable people information efficiently. In addition, we present a system which reconstructs people information that satisfies the users' demand with the ontology.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1964-1967
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• 2002

Recently design verification have been played an important role in the design of large scale and complex systems. In this article, we especially focus on model checking methods. Behaviors of modeled systems are generally specified by temporal formulas of computation tree logic. However. Users must know well temporal specification because the specification might be complex. We proposed method that temporal formulas are gained inductively and amounts of memory and time are reduced. Finally, we will show verification results using our proposed method.

• Korea Information Processing Society Review
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• v.11 no.6
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• pp.56-75
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• 2004

In this article we address some system characteristics and challenging issues in developing Context-aware Middleware for Ubiquitous Computing. The functionalities of a Context-aware Middleware includes gathering context data from hardware/software sensors, reasoning and inferring high-level context data, and disseminating/delivering appropriate context data to interested applications/services. The Middleware should facilitate the query, aggregation, and discovery for the contexts, as well as facilities to specify their privacy policy. Following a formal context model using ontology would enable syntactic and semantic interoperability, and knowledge sharing between different domains. Moddleware should also provide different kinds of context classification mechanical as pluggable modules, including rules written in different types of logic (first order logic, description logic, temporal/spatial logic, fuzzy logic, etc.) as well as machine-learning mechanical (supervised and unsupervised classifiers). Different mechanisms have different power, expressiveness and decidability properties, and system developers can choose the appropriate mechanism that best meets the reasoning requirements of each context. And finally, to promote the context-trigger actions in application level, it is important to provide a uniform and platform-independent interface for applications to express their need for different context data without knowing how that data is acquired. The action could involve adapting to the new environment, notifying the user, communicating with another device to exchange information, or performing any other task.