30 research outputs found
APQL: A process-model query language
As business process management technology matures, organisations acquire more and more business process models. The management of the resulting collections of process models poses real challenges. One of these challenges concerns model retrieval where support should be provided for the formulation and efficient execution of business process model queries. As queries based on only structural information cannot deal with all querying requirements in practice, there should be support for queries that require knowledge of process model semantics. In this paper we formally define a process model query language that is based on semantic relationships between tasks in process models and is independent of any particular process modelling notation
Higher-Dimensional Timed Automata
We introduce a new formalism of higher-dimensional timed automata, based on
van Glabbeek's higher-dimensional automata and Alur's timed automata. We prove
that their reachability is PSPACE-complete and can be decided using zone-based
algorithms. We also show how to use tensor products to combat state-space
explosion and how to extend the setting to higher-dimensional hybrid automata
Petri Games: Synthesis of Distributed Systems with Causal Memory
We present a new multiplayer game model for the interaction and the flow of
information in a distributed system. The players are tokens on a Petri net. As
long as the players move in independent parts of the net, they do not know of
each other; when they synchronize at a joint transition, each player gets
informed of the causal history of the other player. We show that for Petri
games with a single environment player and an arbitrary bounded number of
system players, deciding the existence of a safety strategy for the system
players is EXPTIME-complete.Comment: In Proceedings GandALF 2014, arXiv:1408.556
Processus de branchement des réseaux de Petri à reset arcs
National audienceLes réseaux de Petri sont un outil très répandu de modélisation et d'étude des systèmes concur-rents autour desquels s'est constituée une large communauté scientifique. Il existe des extensions qui ont pour but d'étendre le formalisme de référence par les réseaux de Petri pour proposer soit des mo-dèles plus compacts en termes de description, soit plus puissants en termes de pouvoir d'expression. Nous pouvons citer entre autre l'ajout des reset arcs qui ajoutent un pouvoir expressif utile en ce sens qu'ils permettent de remettre à zéro (notion de réinitialisation) le contenu d'une place sans impacter sur les règles de sensibilisation des transitions dans le réseau. Nous proposons pour les réseaux de Petri à reset arcs ayant un réseau normal sous-jacent borné, une approche pour construire le dépliage (méthode d'ordre partiel pour contourner le problème d'explosion combinatoire lié à la construction du graphe d'états) et d'un préfixe complet et fini du dépliage. Nous présenterons aussi un algorithme pour l'identification des processus de branchement issus d'un tel dépliage
A Nice Labelling for Tree-Like Event Structures of Degree 3 (Extended Version)
We address the problem of finding nice labellings for event structures of
degree 3. We develop a minimum theory by which we prove that the labelling
number of an event structure of degree 3 is bounded by a linear function of the
height. The main theorem we present in this paper states that event structures
of degree 3 whose causality order is a tree have a nice labelling with 3
colors. Finally, we exemplify how to use this theorem to construct upper bounds
for the labelling number of other event structures of degree 3
Algebraic Structure of Combined Traces
Traces and their extension called combined traces (comtraces) are two formal
models used in the analysis and verification of concurrent systems. Both models
are based on concepts originating in the theory of formal languages, and they
are able to capture the notions of causality and simultaneity of atomic actions
which take place during the process of a system's operation. The aim of this
paper is a transfer to the domain of comtraces and developing of some
fundamental notions, which proved to be successful in the theory of traces. In
particular, we introduce and then apply the notion of indivisible steps, the
lexicographical canonical form of comtraces, as well as the representation of a
comtrace utilising its linear projections to binary action subalphabets. We
also provide two algorithms related to the new notions. Using them, one can
solve, in an efficient way, the problem of step sequence equivalence in the
context of comtraces. One may view our results as a first step towards the
development of infinite combined traces, as well as recognisable languages of
combined traces.Comment: Short variant of this paper, with no proofs, appeared in Proceedings
of CONCUR 2012 conferenc