• ETRI Journal
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• v.18 no.4
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• pp.245-264
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• 1997

This paper presents a formalism-based methodology and its implemented environment which constitutes a sound framework for real-time systems development. The software and/or hardware systems developed in such a formal manner are well structured and maintainable. We first propose a set-theoretic VSSS (Variable Structure System Specification) formalism. This formalism is the core of the presented methodology which supports a means of formal specification for real-time systems. We then develop the environment, including VSSS language definition, a translator for the language, and supporting libraries for real-time execution. Finally, a demonstration of the methodology in development of a real-time event manager, a subsystem of an ATM-based communication system, shows the correctness and efficiency of the methodology.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.226-232
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• 2000

The design of agricultural facilities is the consistent activities, which systematically analyze all the actual conditions, design the unit structures, and improve the faming environment through efficient organization of the unit facility. The design of agricultural facilities is composed of site study, preliminary design, primary design, and detail design. Integrated design system can manage and process the information created by and used in all steps of design process. Formal data models of these design activities are important conceptual steps in development of integrated design system. However, most of existing models are not available for agricultural facilities. To support efficiently developing the integrated design system of agricultural facilities, we have developed the Multi-Layered Primitive-Composite mode I through object-oriented analysis of agricultural facilities. The MPC model not only satisfies the characteristics of agricultural facility, such as variety, coupling, informal data, but also improves abilities of integrated design system such as extensibility, flexibility, and granularity. The paper presents a formal definition of the MPC model.

• Proceedings of the IEEK Conference
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• summer
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• pp.355-360
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• 2004

With the growing acceptance of XML technologies, XML will be the most common tool for all data manipulation and data transmission. Meeting security requirements for privacy, confidentiality and integrity is essential in order to move business online and it is important for security to be integrated with XML solutions. Many policies require certain conditions to be satisfied and actions to be performed before or after a decision is made. Binary yes/no decision to an access request is not enough for many applications. These issues were addressed and formalized as provisions and obligations by Betti et Al. In this paper, we propose an authorization model with provisions and obligations in XML. We introduce a formal definition of authorization policy and the issues involving obligation discussed by Betti et Al. We use the formal model as a basis to develop an authorization model in XML. We develop DTDs in XML for main components such as authorization request, authorization policy and authorization decision. We plan to develop an authorization system using the model proposed.

• The Journal of the Acoustical Society of Korea
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• v.15 no.4E
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• pp.53-57
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• 1996

An extension of the well-known Fourier transform is developed in this paper. It is denoted as the generalized Fourier transform(GFT), since it encompasses the Fourier transform as its special case. The first idea of this extension can be found on [1]. In the definition of the N-point discrete GFT, it first construct a passband in time which functions as a window in the time domain. An appropriate interpretation of each variables are introduced during the definition of the GFT, followed by the formal derivation of the inverse GFT. This transform pair is similar to the windowing in the frequency domain such as the subband coding technique (or filter bank approach) and could be extended to the wavelet transform.

• Asia pacific journal of information systems
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• v.12 no.2
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• pp.99-118
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• 2002

In this paper, we propose a visual relational database query language, VRQL, by modifying and extending the recently proposed $VOQL^*$. Like $VOQL^*$, VRQL, based on ven Diagram and graph, naturally reflects the structure of schemas in queries and has recursive formal semantics. However, VRQL has relationally complete expressiveness, while $VOQL^*$ is only a conjunctive query language. In the logical definition part of VRQL, which is the relational version of $VOQL^*$, most features of $VOQL^*$ are retained, and the semantics of queries are based on the tuple relational calculus. In the procedural definition part of VRQL, by introducing the concept of VRQL view and set operations, the expressiveness of VRQL is increased to the level equivalent to that of the relational algebra. Due to the introduction of VRQL views, existing queries or temporary queries used in the process of creating queries can be represented with views, so that complex queries may be represented more conveniently. Set operations, used with VRQL views, enable us to represent various queries, beyond the expressiveness of conjunctive query languages.

• Journal of Computing Science and Engineering
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• v.2 no.1
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• pp.74-97
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• 2008

A scheduling policy or a schedulability test is defined to be sustainable if any task system determined to be schedulable remains so if it behaves "better" than mandated by its system specifications. We provide a formal definition of sustainability, and subject the concept to systematic analysis in the context of the uniprocessor scheduling of periodic and sporadic task systems. We argue that it is, in general, preferable engineering practice to use sustainable tests if possible, and classify common uniprocessor schedulability tests according to whether they are sustainable or not.

• Industrial Engineering and Management Systems
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• v.15 no.2
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• pp.143-147
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• 2016

Uncertainty appears not only in real quantities but also in complex quantities. Complex uncertain process is essentially a sequence of complex uncertain variables indexed by time. In order to describe complex uncertain process, a formal definition of complex uncertain distribution is given in this paper, as well as the concepts of independence and variance. In addition, some properties of complex uncertain integral are presented.

• Bulletin of the Korean Mathematical Society
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• v.28 no.2
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• pp.185-190
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• 1991

The concept of "almost invertibility modulo closed ideals" in L(X, Y) was introduced, implicitly, by Robin Harte [1, Theorem 3.9.5]. The aims of this note are to make the formal definition of "almost left and right invertible modulo closed ideals" operators and show that they form open sets.they form open sets.

• The Transactions of the Korea Information Processing Society
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• v.5 no.12
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• pp.3127-3137
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• 1998

COBRA 표준명세는 표준을 만족하는 구현에서 제공해야 할 기능뿐만 아니라 서비스 제공 모듈의 사용자 인터페이스도 IDL을 사용하여 엄격하게 정의하고 있다. CORBA 표준에 대한 확신과 신뢰성을 가지기 위해서는 IDL(Interface Definition Language)로 기술된 표준명세를 정형화하고 수학적으로 엄격히 증명할 필요가 있다. 본 논문에서는 CORBA 표준을 정형적으로 명세하고 검증할 방법을 제시한다. 먼저 표준모듈을 Larch/CORBA IDL(LCB)를 사용하여 정형적으로 명세하고, LCB의 의미론에 준하여 LCB 명세를 LSL(Larch Shared language)로 변환한다. 변환한 LCB 명세와 LSL 증명논리를 사용하여 특성을 수학적으로 증명한다. 변환기반의 LCB 의미론을 정립하여 제안한 방법의 이론적 바탕을 마련하고 CORBA 이름서비스명세에 실제 적용하여 그 효용성을 보인다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.439-442
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• 2002

컴포넌트 명세는 컴포넌트와 클라이언트 사이의 계약으로 볼 수 있다. 하지만 현재의 컴포넌트 명세는 인터페이스 명세 언어(Interface Definition Language)와 정확성이 결여된 자연어로 작성된 명세에 의존하고 있다. 이러한 명세는 모호성, 불완전성, 모순등을 포함할 수 있다. 따라서 컴포넌트 명세는 이러한 점을 충분히 고려하여 진행되어야 하는데 본 연구에서는 EJB 컴포넌트의 코드 템플릿을 반영하여 요구사항을 Object-Z로 명세하고 이러한 명세로부터 컴포넌트를 구현하는 단계를 제시하였다.