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Software, IEE Proceedings -

Issue 5 • Date Oct 2001

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  • Real-time design in a distributed control network application layer environment

    Page(s): 149 - 155
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (674 KB)  

    The use of communication networks in time-critical control applications presents designers with special problems in the determination of response times for communicating distributed tasks. In the paper, using a 'structured analysis' design approach, a real-time distributed application can be mapped to an application layer of a control network and guaranteed to meet its real-time requirements. The CAN (Controller Area Network) along with the CAN Application Layer (CAL) has been chosen as the experimental network. The 'CAN Messaging Service' (CMS) elements of CAL are carefully selected to implement the 'distributed' information flows and event flows produced by the 'structured design' methodology. A real-time analysis approach for CALs CMS service elements is developed. Intelligent use of CALs inhibit times allow modelling of an event-driven system with properties inherent to a periodic system. Combining the worst-case computational, queuing and transmission delays, the response time for each distributed task can then be evaluated. This allows 'fine tuning' of the distributed tasks until they can be guaranteed to meet their deadlines View full abstract»

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  • Aspect-orientation and database systems: an effective customisation approach

    Page(s): 156 - 164
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (868 KB)  

    The problem of providing database systems customised to the specific needs of an organisation or application is addressed. The authors demonstrate that such customisations are expensive in existing database systems owing to the crosscutting nature of customisable features, and they propose a customisation approach based on 'aspect-oriented programming' techniques which allow separation of crosscutting features using special constructs known as 'aspects'. Changes to the features encapsulated by aspects are localised, making cost-effective customisation possible (at compile-time and run-time) at both the DBMS level and the database level View full abstract»

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