30,415 research outputs found

    A Data Oriented Approach for Real-Time Systems

    Get PDF
    International audienceDistributed real-time systems often have to maintain the temporal validity of data. In this paper we present a modelling framework centered on data where a so-called observation relation represents and abstracts the interactions between variables. An observation is a relation between variables, an image and its sources, where the image values depend on past values of the sources. The system architecture is seen as a set of observation relations describing the flow of values between variables. The observation relations are parametrized with timed constraints that limit the time shift between the variables and specify the availability of timely sound values. At this level of abstraction, the designer gives a specification of the system based on timed properties about the timeline of data such as their freshness, latency etc. We proceed to an analysis of the feasibility of such a specification and we formally analyze the correctness of an implementation with respect to a specification. In order to prove the feasibility of an observationbased model, we build a finite state transition system which is bi-similar to the specification. The existence of an infinite execution in this system proves the feasibility of the specification. Possible implementations are described as a set of interacting components which control the flow of values in the system. A finite system is built to prove the correctness of the implementation by model checkin

    A Formal Model For Real-Time Parallel Computation

    Full text link
    The imposition of real-time constraints on a parallel computing environment- specifically high-performance, cluster-computing systems- introduces a variety of challenges with respect to the formal verification of the system's timing properties. In this paper, we briefly motivate the need for such a system, and we introduce an automaton-based method for performing such formal verification. We define the concept of a consistent parallel timing system: a hybrid system consisting of a set of timed automata (specifically, timed Buchi automata as well as a timed variant of standard finite automata), intended to model the timing properties of a well-behaved real-time parallel system. Finally, we give a brief case study to demonstrate the concepts in the paper: a parallel matrix multiplication kernel which operates within provable upper time bounds. We give the algorithm used, a corresponding consistent parallel timing system, and empirical results showing that the system operates under the specified timing constraints.Comment: In Proceedings FTSCS 2012, arXiv:1212.657

    Test Derivation from Timed Automata

    Get PDF
    A real-time system is a discrete system whose state changes occur in real-numbered time [AH97]. For testing real-time systems, specification languages must be extended with constructs for expressing real-time constraints, the implementation relation must be generalized to consider the temporal dimension, and the data structures and algorithms used to generate tests must be revised to operate on a potentially infinite set of states

    Model checking embedded system designs

    Get PDF
    We survey the basic principles behind the application of model checking to controller verification and synthesis. A promising development is the area of guided model checking, in which the state space search strategy of the model checking algorithm can be influenced to visit more interesting sets of states first. In particular, we discuss how model checking can be combined with heuristic cost functions to guide search strategies. Finally, we list a number of current research developments, especially in the area of reachability analysis for optimal control and related issues
    • 

    corecore