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Unfoldingbased diagnosis of systems with an evolving topology
, 2008
"... Abstract. We propose a framework for modelbased diagnosis of systems with mobility and variable topologies, modelled as graph transformation systems. Generally speaking, modelbased diagnosis is aimed at constructing explanations of observed faulty behaviours on the basis of a given model of the sy ..."
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Cited by 13 (7 self)
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Abstract. We propose a framework for modelbased diagnosis of systems with mobility and variable topologies, modelled as graph transformation systems. Generally speaking, modelbased diagnosis is aimed at constructing explanations of observed faulty behaviours on the basis of a given model of the system. Since the number of possible explanations may be huge we exploit the unfolding as a compact data structure to store them, along the lines of previous work dealing with Petri net models. Given a model of a system and an observation, the explanations can be constructed by unfolding the model constrained by the observation, and then removing incomplete explanations in a pruning phase. The theory is formalised in a general categorical setting: constraining the system by the observation corresponds to taking a product in the chosen category of graph grammars, so that the correctness of the procedure can be proved by using the fact that the unfolding is a right adjoint and thus it preserves products. The theory thus should be easily applicable to a wide class of system models, including graph grammars and Petri nets. 1
Appligraph: Applications of Graph Transformation  Fourth Annual Progress Report
, 2001
"... This report summarizes the activities in the fourth year of the ESPRIT Working Group APPLIGRAPH, covering the period from April 1, 2000, to March 31, 2001. The principal objective of this Working Group is to promote applied graph transformation as a rulebased framework for the specication and devel ..."
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Cited by 1 (0 self)
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This report summarizes the activities in the fourth year of the ESPRIT Working Group APPLIGRAPH, covering the period from April 1, 2000, to March 31, 2001. The principal objective of this Working Group is to promote applied graph transformation as a rulebased framework for the specication and development of systems, languages, and tools and to improve the awareness of its industrial relevance
Multirelational Semantics for Extended
 In Conceptual ModelingER 2002. 21st International Conference on Conceptual Modeling, number 2503 in Lecture Notes in Computer Science
, 2002
"... This paper describes a multirelation semantics for a fragment of the Extended EntityRelationship schemata formalism based on the bicategorical definition of multirelations. The approach we follow is elementarywe try to introduce as few notions as possible. We claim that bicategorical algebra ..."
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This paper describes a multirelation semantics for a fragment of the Extended EntityRelationship schemata formalism based on the bicategorical definition of multirelations. The approach we follow is elementarywe try to introduce as few notions as possible. We claim that bicategorical algebra handles gracefully multirelations and their operations, and that multirelations are essential in a number of applications; moreover, the bicategorical composition of multirelations turns out to correspond to natural joins. From the formal semantics we derive an algorithm that can establish statically the possibility of building parallel ownership paths of weak entities. The ideas described in this paper have been implemented in a free tool, ERW, which lets users edit sets and multirelations instantiating an EER schema via a sophisticated web interface.
Collagory Notes, Version 1
, 2010
"... These notes are a current snapshot of the development of the theory of collagories, which are defined essentially as “distributive allegories without zero morphisms ” and named for their close relationship with the adhesive categories currently popular as a foundation for the categorical doublepush ..."
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These notes are a current snapshot of the development of the theory of collagories, which are defined essentially as “distributive allegories without zero morphisms ” and named for their close relationship with the adhesive categories currently popular as a foundation for the categorical doublepushout approach to graph transformation. We argue that, thanks to their relationalgebraic flavour, collagories provide a more accessible and more flexible setting. One contributing factor to this is that the universal characterisations of pushouts and pullbacks in categories can be replaced with the local characterisations of tabulations and cotabulations in collagories. We document accessibility by showing ways to construct collagories of semiunary algebras, which allow natural representations in particular of graph structures, also with fixed label sets. Via the local ordering on homsets, collagories have a simple 2categorical structure, and we use this to show that cotabulations are equivalent to lax colimits of difunctional morphisms, and cotabulations arising from spans of mappings are equivalent to bipushouts, which satisfy stronger conditions than just pushouts of mappings.
Unfoldingbased Diagnosis of Systems with an Evolving Topology ✩
, 2011
"... We propose a framework for modelbased diagnosis of systems with mobility and variable topologies, modelled as graph transformation systems. Generally speaking, modelbased diagnosis is aimed at constructing explanations of observed faulty behaviours on the basis of a given model of the system. Sinc ..."
Abstract
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We propose a framework for modelbased diagnosis of systems with mobility and variable topologies, modelled as graph transformation systems. Generally speaking, modelbased diagnosis is aimed at constructing explanations of observed faulty behaviours on the basis of a given model of the system. Since the number of possible explanations may be huge, we exploit the unfolding as a compact data structure to store them, along the lines of previous work dealing with Petri net models. Given a model of a system and an observation, the explanations can be constructed by unfolding the model constrained by the observation, and then removing incomplete explanations in a pruning phase. The theory is formalised in a general categorical setting: constraining the system by the observation corresponds to taking a product in the chosen category of graph grammars, so that the correctness of the procedure can be proved by using the fact that the unfolding is a right adjoint and thus it preserves products. The theory should hence be easily applicable to a wide class of system models, including graph grammars and Petri nets. Key words: Modelbased diagnosis, distributed and concurrent systems, partial order methods, graph rewriting