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36
Matching of Bigraphs
 PREPRINT OF GTVC 2006
, 2006
"... We analyze the matching problem for bigraphs. In particular, we present a sound and complete inductive characterization of matching of binding bigraphs. Our results pave the way for a provably correct matching algorithm, as needed for an implementation of bigraphical reactive systems. ..."
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Cited by 24 (12 self)
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We analyze the matching problem for bigraphs. In particular, we present a sound and complete inductive characterization of matching of binding bigraphs. Our results pave the way for a provably correct matching algorithm, as needed for an implementation of bigraphical reactive systems.
Typed polyadic picalculus in bigraphs
 Proceedings of the 8th International Symposium on Principles and Practice of Declarative Programming (PPDP'06)
, 2006
"... Bigraphs have been introduced with the aim to provide a topographical metamodel for mobile, distributed agents that can manipulate their own communication links and nested locations. In this paper we examine a presentation of type systems on bigraphical systems using the notion of sorting. We focus ..."
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Cited by 20 (2 self)
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Bigraphs have been introduced with the aim to provide a topographical metamodel for mobile, distributed agents that can manipulate their own communication links and nested locations. In this paper we examine a presentation of type systems on bigraphical systems using the notion of sorting. We focus our attention on the typed polyadic πcalculus with capability types à la Pierce and Sangiorgi, which we represent using a novel kind of link sorting called subsorting. Using the theory of relative pushouts we derive a labelled transition system which yield a coinductive characterisation of a behavioural congruence for the calculus. The results obtained in this paper constitute a promising foundation for the presentation of various type systems for the (polyadic) πcalculus as sortings in the setting of bigraphs.
On the Construction of Sorted Reactive Systems
 IN PROCEEDINGS OF CONCUR’08, LNCS
, 2008
"... We develop a theory of sorted bigraphical reactive systems. Every application of bigraphs in the literature has required an extension, a sorting, of pure bigraphs. In turn, every such application has required a redevelopment of the theory of pure bigraphical reactive systems for the sorting at hand. ..."
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Cited by 10 (5 self)
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We develop a theory of sorted bigraphical reactive systems. Every application of bigraphs in the literature has required an extension, a sorting, of pure bigraphs. In turn, every such application has required a redevelopment of the theory of pure bigraphical reactive systems for the sorting at hand. Here we present a general construction of sortings. The constructed sortings always sustain the behavioural theory of pure bigraphs (in a precise sense), thus obviating the need to redevelop that theory for each new application. As an example, we recover Milner’s local bigraphs as a sorting on pure bigraphs. Technically, we give our construction for ordinary reactive systems, then lift it to bigraphical reactive systems. As such, we give also a construction of sortings for ordinary reactive systems. This construction is an improvement over previous attempts in that it produces smaller and much more natural sortings, as witnessed by our recovery of local bigraphs as a sorting.
Static bilog: a unifying language for spatial structures
 Fundamenta Informaticae
, 2007
"... Abstract. Aiming at a unified view of the logics describing spatial structures, we introduce a general framework, BiLog, whose formulae characterise monoidal categories. As a first instance of the framework we consider bigraphs, which are emerging as a an interesting (meta)model for spatial struct ..."
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Cited by 9 (0 self)
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Abstract. Aiming at a unified view of the logics describing spatial structures, we introduce a general framework, BiLog, whose formulae characterise monoidal categories. As a first instance of the framework we consider bigraphs, which are emerging as a an interesting (meta)model for spatial structures and distributed calculi. Since bigraphs are built orthogonally on two structures, a hierarchical place graph for locations and a link (hyper)graph for connections, we obtain a logic that is a natural composition of other two instances of BiLog: a Place Graph Logic and a Link Graph Logic. We prove that these instances generalise the spatial logics for trees, for graphs and for tree contexts. We also explore the concepts of separation and sharing in these logics. We note that both the operator * of Separation Logic and the operator  of spatial logics do not completely separate the underlying structures. These two different forms of separation can be naturally derived as instances of BiLog by using the complete separation induced by the tensor product of monoidal categories along with some form of sharing.
Axiomatizing Binding Bigraphs
 NORDIC JOURNAL OF COMPUTING
, 2006
"... We axiomatize the congruence relation for binding bigraphs and prove that the generated theory is complete. In doing so, we define a normal form for binding bigraphs, and prove that it is unique up to certain isomorphisms. Our work builds on Milner’s axioms for pure bigraphs. We have extended the ..."
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Cited by 6 (0 self)
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We axiomatize the congruence relation for binding bigraphs and prove that the generated theory is complete. In doing so, we define a normal form for binding bigraphs, and prove that it is unique up to certain isomorphisms. Our work builds on Milner’s axioms for pure bigraphs. We have extended the set of axioms with five new axioms concerned with binding, and we have altered some of Milner’s axioms for ions, because ions in binding bigraphs have names on both their inner and outer faces. The resulting theory is a conservative extension of Milner’s for pure bigraphs.
Incremental awareness and compositionality: a design philosophy for contextaware pervasive systems, Pervasive and Mobile Computing 6 (2
, 2010
"... Contextaware pervasive systems are an important emerging category of software, increasingly pervading into daily life, play and work. These systems are characterized by capabilities for sensing the physical world and taking action, autonomously or in cooperation with users. This paper proposes an ..."
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Cited by 4 (0 self)
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Contextaware pervasive systems are an important emerging category of software, increasingly pervading into daily life, play and work. These systems are characterized by capabilities for sensing the physical world and taking action, autonomously or in cooperation with users. This paper proposes an incremental approach to building contextaware pervasive systems, with a particular emphasis on systematically extending over time the contexts and situations a system can be aware of, and creating a formalism in which these systems can be composed. We present a formalism of operators for building contextaware pervasive systems incrementally and in a compositional manner (by combining multiple systems and subsystems), facilitating reuse in a formal way. The formalism can serve as (i) a basis for a scripting language for programming composite systems, and (ii) a language for specifying these systems (whether existing or to be built) and then reasoning with specifications of these systems. 1
BigActors A Model for Structureaware Computation ∗
"... This paper describes a model of computation for structureaware computing called the BigActor model. The model is a hybrid. It combines the Actor model [1] and the Bigraph model [10]. The contributions of this paper are an operational semantics, an example illustrating how the model supports the conc ..."
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Cited by 4 (1 self)
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This paper describes a model of computation for structureaware computing called the BigActor model. The model is a hybrid. It combines the Actor model [1] and the Bigraph model [10]. The contributions of this paper are an operational semantics, an example illustrating how the model supports the concise programming of a mobile agent working in a ubiquitous computing world, a query language enabling a bigActor to observe the world around it, and a definition giving semantics to the feedback loop in control theory in the context of this model. This is followed by three theorems showing how the operational semantics supports the programming of concurrent mobile agents in the semantics of feedback control.
Secure Data Flow in a Calculus for Context Awareness
"... Abstract. We present a MobileAmbientsbased process calculus to describe contextaware computing in an infrastructurebased Ubiquitous Computing setting. In our calculus, computing agents can provide and discover contextual information and are owners of security policies. Simple access control to c ..."
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Abstract. We present a MobileAmbientsbased process calculus to describe contextaware computing in an infrastructurebased Ubiquitous Computing setting. In our calculus, computing agents can provide and discover contextual information and are owners of security policies. Simple access control to contextual information is not sufficient to insure confidentiality in Global Computing, therefore our security policies regulate agents ’ rights to the provision and discovery of contextual information over distributed flows of actions. A type system enforcing security policies by a combination of static and dynamic checking of mobile agents is provided, together with its type soundness. Key words: Ubiquitous Computing, Mobile Ambients, context awareness, security, type system 1
Computer Supported Mobile Adaptive Business Processes? Position paper on the CosmoBiz research project (20072010) www.cosmobiz.org
"... Dynamic evolution of work ow process descriptions and active instances has been an active research area since the mid 1990s. Most work has been based on flowgraph meta models formalised as variations of Petri Nets. We present a new research project on Computer Supported Mobile Adaptive Business Pr ..."
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Cited by 4 (1 self)
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Dynamic evolution of work ow process descriptions and active instances has been an active research area since the mid 1990s. Most work has been based on flowgraph meta models formalised as variations of Petri Nets. We present a new research project on Computer Supported Mobile Adaptive Business Processes (CosmoBiz) initiated in January 2007 jointly with Microsoft Development Center Copenhagen, which will extend this work to mobile and distributed work ows, by uniting research in formal models for graph rewriting and typed process calculi, design and implementation of distributed and peertopeer systems, and computer supported collaborative work.