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We identify a network of sequential processes that communicate by synchronizing frequently on common actions. More precisely, we demand that there is a bound k such that if the process p executes k steps without hearing from process q—directly or indirectly—then it will never hear from q again. The non-interleaved branching time behavior of a system of(More)
Scenario languages based on Message Sequence Charts (MSCs) and related notations have been widely studied in the last decade [14, 13, 2, 9, 5, 12, 8]. The high expressive power of scenarios renders many basic problems concerning these languages undecidable. The most expressive class for which several problems are known to be decidable is one which possesses(More)
Systems involving both time and concurrency are notoriously difficult to analyze. Existing decidability results apply in settings where clocks on different processes cannot be compared or where the set of timed executions is regular. We prove new decidability results for timed concurrent systems, requiring neither restriction. We consider the formalism of(More)
We show the regularity of the discrete time behaviour of hybrid automata in which the rates of continuous variables are governed by linear differential operators in a diagonal form and in which the values of the continuous variables can be observed only with finite precision. We do not demand resetting of the values of the continuous variables during mode(More)
Verifying systems involving both time and concurrency rapidly leads to undecidability, and requires restrictions to become effective. This paper addresses the emptiness problem for time-constrained MSC-Graphs (TC-MSC graphs for short), that is, checking whether there is a timed execution compatible with a TC-MSC graph specification. This problem is known to(More)
Good scheduling policies for distributed embedded applications are required for meeting hard real time constraints and for optimizing the use of computational resources. We study the quasi-static scheduling problem in which (uncontrollable) control flow branchings can influence scheduling decisions at run time. Our abstracted distributed task model consists(More)
We consider a network of controllers that observe and control a plant whose dynamics is determined by a finite set of continuous variables. At any given time a variable evolves at a constant rate. However, a controller can switch the rates of a designated subset of the continuous variables. These mode changes are determined by the current values of a(More)
Foreword This technical report contains a research paper, development or tutorial article, which has been submitted for publication in a journal or for consideration by the commissioning organization. The report represents the ideas of its author, and should not be taken as the official views of the School or the University. Any discussion of the content of(More)