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Chicago J. Theor. Comput. Sci. 01/2010; 2010.
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Computer Science 2006, Twenty-Nineth Australasian Computer Science Conference (ACSC2006), Hobart, Tasmania, Australia, January 16-19 2006; 01/2006
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Integrated Formal Methods, 5th International Conference, IFM 2005, Eindhoven, The Netherlands, November 29 - December 2, 2005, Proceedings; 01/2005
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Petra Malik
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ABSTRACT: This paper points out problems that occur when controllercode for discrete-event systems is generated from models based on supervisory control. The communication problem and the determinism problem are illustrated by means of a simple example. Some possible solutions for these problems are suggested and compared.
03/2003;
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ABSTRACT: This paper presents an efficient algorithm to detect control-loops in large finite-state systems. The proposed algorithm exploits the modular structure present in many models of practical relevance, and often successfully avoids the explicit synchronous composition of subsystems and thereby the state explosion problem. Experimental results show that the method can be used to verify industrial applications of considerable complexity. Copyright IEEE 2006
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ABSTRACT: This paper presents supervisory control theory in a process-algebraic setting, and proposes a way of synthesising modular supervisors that guarantee nonblocking. The framework used includes the possibility of hiding actions which results in nondeterminism. As modularity crucially depends on the process equivalence used, the paper studies possible equivalences and points out that, in order to be consistent with respect to the nonblocking property and to supervisor synthesis, a conflict-preserving equivalence must be used. It applies the results to synthesise nonblocking modular supervisors for a manufacturing system. Copyright IEEE 2007
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ABSTRACT: This paper describes our experience when applying formal methods in the design of the tourist information system TIP, which presents context-sensitive information to mobile users with small screen devices. The dynamics of this system are very complex and pose several challenges, firstly because of the sophisticated interaction of several applications on a small screen device and the user, and secondly because of the need for communication with highly asynchronous event-based information systems. UML sequence diagrams have been used to capture the requirements and possible interactions of the system. In a second step, a formal model has been created using discrete event systems, in order to thoroughly understand and analyse the dynamics of the system. By verifying general properties of the formal model, several conceptual difficulties have been revealed in very early stages of the design process, considerably speeding up the development. This work shows the limitations of typical methods for interaction design when applied to mobile systems using small screen devices and proposes an alternative approach using discrete event systems.
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ABSTRACT: We propose a simple framework for validation unit testing of Z specifications, and illustrate this framework by testing the first few levels of a POSIX specification. The tests are written in standard Z, and are executable by the CZT animator, ZLive.
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ABSTRACT: The Community Z Tools (CZT) project is an open-source Java framework for building formal methods tools for Z and Z dialects. It also includes a set of tools for parsing, typechecking, transforming and printing standard Z specifications in LATEX , Unicode or XML formats. This paper gives an overview of the CZT framework, including an introduction to its visitor design pattern that makes it possible to write new Z transformation tools in just a few lines of Java code. The paper also discusses several problems and challenges that arose when attempting to build tools based on the SO Standard for Z.
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Petra. Malik
