• Nuclear Engineering and Technology
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• 제32권6호
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• pp.537-548
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• 2000

The requirement of ultra high reliability of the safety critical software can not be demonstrated by testing alone. The specification based on formal method is recommended for safety system software. But there exist various kinds of formal methods, and this variety of formal method is recognized as an obstacle to the wide use of formal method. In this paper six different formal method have been applied to the same part of the functional requirements that is calculation algorithm intensive. The specification results were compared against the criteria that is derived from the characteristics that good software requirements specifications should have and regulatory body recommends to have. The application experience shows that the critical characteristics should be defined first, then appropriate method has to be selected. In our case, the Software Cost Reduction method was recommended for internal condition or calculation algorithm checking, and statechart method is recommended for the external behavioral description.

• Journal of Electrical Engineering and Technology
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• 제4권1호
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• pp.87-92
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• 2009

Many critical control systems are developed using formal methods. When software applied to such systems is developed, the employment of formal methods in the software requirements specification and verification will provide increased assurance for such applications. Earlier errors of overlooked requirement specification can be detected using the formal specification method. Also, the testing and full verification to examine all reachable states using model checking to undertake formal verification are able to be completed. In this paper, we proposed an eclectic approach to incorporate Z(Zed) formal language and 'Statemate MAGNUM', formal method tools using Statechart. Also we applied the proposed method to train control systems for the formal requirement specification and analyzed the specification results.

• 충청수학회지
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• 제25권3호
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• pp.381-391
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• 2012

In this paper, the formal linearization method is used to construct multisoliton solutions for three model of shallow water waves equations. The three models are completely integrable. The formal linearization method is an efficient method for obtaining exact multisoliton solutions of nonlinear partial differential equations. The method can be applied to nonintegrable equations as well as to integrable ones.

• 대한수학회논문집
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• 제26권2호
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• pp.207-214
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• 2011

The formal linearization method is an efficient method for constructing multisoliton solution of some nonlinear partial differential equations. This method can be applied to nonintegrable equations as well as to integrable ones. In this paper, we obtain multisoliton solution of generalization Burger's equation and the (3+1)-dimension Burger's equation and the Boussinesq equation by the formal linearization method.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1000-1007
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• 2007

Recently, many critical control systems are developed using formal methods. When software applied to such systems is developed, the employment of formal methods in the software requirements specification and verification will provide increased assurance for such applications. Earlier error of overlooked requirement specification can be detected using formal specification method. Also the testing and full verification to examine all reachable states using model checking to undertake formal verification are able to be completed. In the comparison of other formal specification methods, we choose the Z formal language for applying to the train control system. Using Z is able to realize higher correctness in the requirement specification, and we propose the Statemate of the best solution in formal verification tools for the system modeling and verification. The Statemate makes it possible to prove thoroughly the system execution from the simple graphical modeling of the complicated train control system. Then we can expect that the model-based formal method combining Z with Statemate will be utilized widely for the railway systems due to various strong points.

• Journal of Information Processing Systems
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• 제11권2호
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• pp.184-204
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• 2015

Fuzzy Formal Concept Analysis (FCA) is a mathematical tool for the effective representation of imprecise and vague knowledge. However, with a large number of formal concepts from a fuzzy context, the task of knowledge representation becomes complex. Hence, knowledge reduction is an important issue in FCA with a fuzzy setting. The purpose of this current study is to address this issue by proposing a method that computes the corresponding crisp order for the fuzzy relation in a given fuzzy formal context. The obtained formal context using the proposed method provides a fewer number of concepts when compared to original fuzzy context. The resultant lattice structure is a reduced form of its corresponding fuzzy concept lattice and preserves the specialized and generalized concepts, as well as stability. This study also shows a step-by-step demonstration of the proposed method and its application.

• 전기학회논문지P
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• 제57권2호
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• pp.65-71
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• 2008

Recently, many critical control systems are developed using formal methods. When software applied to such systems is developed, the employment of formal methods in the software requirements specification and verification will provide increased. assurance for such applications. Earlier error of overlooked requirement specification can be detected using formal specification method. Also the testing and full verification to examine all reachable states using model checking to undertake formal verification are able to be completed. In this paper, we propose an eclectic approach to incorporate Z(Zed) formal language and 'Statemate MAGNUM' which is formal method tools using Statechart for applying to the railway signaling systems.

• 정보처리학회논문지D
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• 제8D권4호
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• pp.421-426
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• 2001

정형적 개발 방법론은 소프트웨어를 정확하고 체계적으로 개발하기 위하여 사용되며 시스템을 정형 명세 언어를 사용하여 맹세하고 이를 구현할 때까지 점진적으로 시스템을 구체화하는 방법으로 개발한다. VDM은 정형 명세 언어의 하나로서 set, sequence, map의 수학적 추상적 자료구조를 사용하여 시스템을 명세하는데 대부분의 프로그래밍 언어는 이런 자료구조를 가지고 있지 않다. 그러므로 이들 자료구조들의 변환이 필요하며 VDM의 수학적 자료구조들은 프로그래밍 언어의 자료구조인 연결 리스트로 변환 할 수 있다. 본 논문에서는 VDM의 set, sequence, map의 자료구조를 프로그래밍 언어의 자료구조인 연결 리스트로 변환하는 방법과 그 변환의 타당성을 수학적으로 증명하였다.

• International Journal of Railway
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• 제2권3호
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• pp.99-106
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• 2009

Checks and tests before putting safety facilities into service as well as the results of these tests are essential, time consuming and may show great variations between each other. Economic constraints and the increasing complexity associated with the development of computerized tools tend to limit the capacity of the classic approval process (manual or automatic). A reduction of the validation cover rate could result in practice. This is not compatible with the French national plan to renew the interlocking systems of the national network. The method and the tool presented in this paper makes it possible to formally validate new computerized systems or evolutions of existing French interlocking systems with real-time functional interpreted Petri nets. The aim of our project is to provide SNCF with a method for the formal validation of French interlocking systems. A formal proof method by assertion, which is applicable to industrial automation equipment such as interlocking systems, and which covers equally the specification and its real software implementation, is presented in this paper. With the proposed method we completely verify that the system follows all safety properties at all times and does not show superfluous conditions: it replaces all the indoor checks (not the outdoor checks). The advantages expected are a significant reduction of testing time and of the related costs, an increase of the test coverage rate, an answer to the new demand of railway infrastructure maintenance engineering to modify and validate computerized interlocking systems. Formal methods mastery by infrastructure engineers are surely a key to prove that more safety is not necessarily more expensive.

• 한국컴퓨터정보학회논문지
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• 제12권6호
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• pp.123-130
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• 2007

본 논문은 객체모델에서 표현되는 객체와 관련성을 형식명세의 상태와 오퍼레이션 도메인으로의 변환 규칙을 제시하였다. 즉 정보모델의 요소인 객체와 관련성을 형식명세 표현에서 상태영역으로 변환하였다. 동적모델의 상태, 이벤트, 행위를 오퍼레이션 영역으로 변환하였다. 비형식적인 객체모델을 형식 명세 언어로 변환하므로써 객체모델을 정형화된 방법으로 검증할 수 있다. 검증과정을 통해 소프트웨어 개말 초기단계에서 모델링 과정의 편리함과 신뢰성을 제공할 수 있다 또한 검증된 모델과 사용자 요구사항 사이의 일관성을 위해 시뮬레이션 도구를 구현하였다. 시뮬레이션 도구는 적합한 모델의 선택과 검증이 가능하도록 하므로 소프트웨어 개발비용과 노력, 개발 시간을 최소화할 수 있다.