1,185 research outputs found

    A template-based approach for the generation of abstractable and reducible models of featured networks

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    We investigate the relationship between symmetry reduction and inductive reasoning when applied to model checking networks of featured components. Popular reduction techniques for combatting state space explosion in model checking, like abstraction and symmetry reduction, can only be applied effectively when the natural symmetry of a system is not destroyed during specification. We introduce a property which ensures this is preserved, open symmetry. We describe a template-based approach for the construction of open symmetric Promela specifications of featured systems. For certain systems (safely featured parameterised systems) our generated specifications are suitable for conversion to abstract specifications representing any size of network. This enables feature interaction analysis to be carried out, via model checking and induction, for systems of any number of featured components. In addition, we show how, for any balanced network of components, by using a graphical representation of the features and the process communication structure, a group of permutations of the underlying state space of the generated specification can be determined easily. Due to the open symmetry of our Promela specifications, this group of permutations can be used directly for symmetry reduced model checking. The main contributions of this paper are an automatic method for developing open symmetric specifications which can be used for generic feature interaction analysis, and the novel application of symmetry detection and reduction in the context of model checking featured networks. We apply our techniques to a well known example of a featured network ā€“ an email system

    A generic approach for the automatic verification of featured, parameterised systems

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    A general technique is presented that allows property based feature analysis of systems consisting of an arbitrary number of components. Each component may have an arbitrary set of safe features. The components are defined in a guarded command form and the technique combines model checking and abstraction. Features must fulfill certain criteria in order to be safe, the criteria express constraints on the variables which occur in feature guards. The main result is a generalisation theorem which we apply to a well known example: the ubiquitous, featured telephone system

    Simulation-assisted control in building energy management systems

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    Technological advances in real-time data collection, data transfer and ever-increasing computational power are bringing simulation-assisted control and on-line fault detection and diagnosis (FDD) closer to reality than was imagined when building energy management systems (BEMSs) were introduced in the 1970s. This paper describes the development and testing of a prototype simulation-assisted controller, in which a detailed simulation program is embedded in real-time control decision making. Results from an experiment in a full-scale environmental test facility demonstrate the feasibility of predictive control using a physically-based thermal simulation program

    A framework for developing feature-rich software systems

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    In response to changing requirements and other environmental influences, software systems are increasingly developed incrementally. Successful implementation of new features in existing software is often difficult, whilst many software systems simply `break' when features are introduced. Size and complexity of modern software, poor software design, and lack of appropriate tools are some of the factors that often confound the issue. In this paper, we report on a successful industrial experience of evolving a feature-rich program analysis tool for dependable software systems. The experience highlights the need for a development framework to maintain rich traceability between development artifacts, and to satisfy certain minimal necessary conditions of artifacts during and after the implementation of a new feature

    Programmes in transition - between closure and start. Review of programme developments: Winter-Summer 2007

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    The past six months have seen a shift in emphasis from the 2000-2006 to the 2007-2013 programmes. Programme managers and other implementing organisations have not only been negotiating draft programmes for 2007-2013 with European Commission staff, but have also been undertaking a range of tasks to prepare for implementing these programmes. A number of initiatives have also occurred at EU level, which direct policymakersā€™ attention forward to the EU budget review of 2008-2009 and beyond. In addition, ongoing efforts have been needed to ensure that the remaining funds under the 2000-2006 programmes are effectively absorbed, and that all technical preparations for programme closure are underway

    Review of Machine Vision-Based Electronic Travel Aids

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    Visual impaired people have navigation and mobility problems on the road. Up to now, many approaches have been conducted to help them navigate around using different sensing techniques. This paper reviews several machine vision- based Electronic Travel Aids (ETAs) and compares them with those using other sensing techniques. The functionalities of machine vision-based ETAs are classified from low-level image processing such as detecting the road regions and obstacles to high-level functionalities such as recognizing the digital tags and texts. In addition, the characteristics of the ETA systems for blind people are particularly discussed
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