Reconfigurable Decorated PT Nets with Inhibitor Arcs and Transition Priorities

In this paper we deal with additional control structures for decorated PT Nets. The main contribution are inhibitor arcs and priorities. The first ensure that a marking can inhibit the firing of a transition. Inhibitor arcs force that the transition may only fire when the place is empty. an order of transitions restrict the firing, so that an transition may fire only if it has the highest priority of all enabled transitions. This concept is shown to be compatible with reconfigurable Petri nets

Subtyping for Hierarchical, Reconfigurable Petri Nets

Hierarchical Petri nets allow a more abstract view and reconfigurable Petri nets model dynamic structural adaptation. In this contribution we present the combination of reconfigurable Petri nets and hierarchical Petri nets yielding hierarchical structure for reconfigurable Petri nets. Hierarchies are established by substituting transitions by subnets. These subnets are themselves reconfigurable, so they are supplied with their own set of rules. Moreover, global rules that can be applied in all of the net, are provided

Abstract Interleaving Semantics for Reconfigurable Petri Nets

Reconfigurable Petri nets are Petri nets together with rules for the dynamic change of the nets. We employ them for the formal modeling in the context of the Living Place Hamburg, a smart home that is an urban apartment serving as  a laboratory for investigating different areas of ambient intelligence. The interaction of the resident and the smart home is modeled using informal descriptions of scenarios. These scenarios provide the resident's procedures together with the smart home's support. A case study using reconfigurable Petri nets for modeling these scenarios has required extensions of the theory and has clearly shown the need for an interleaving semantics for reconfigurable Petri nets. Scenarios are then given by nets, namely decorated place/transition nets that can be adapted to the evolving subgoals by applying rules that change the nets and hence the behavior of the smart home. Decorated place/transition nets are annotated place/transition nets with additional transition labels that may change when the transition is fired. To obtain such reconfigurable Petri nets  we prove that decorated place/transition nets  give rise to an M-adhesive HLR category. The abstract interleaving semantics we introduce is a graph with nodes that consist of an isomorphism class of the net structure and an isomorphism class of the current  marking. Arcs between these nodes represent computation steps being either a transition firing or a direct transformation

Towards Partial Composition of Components: Formal Foundation for Component Verification

The intention of this paper is to extend the generic component framework to partial composition. Basic Ideas of partial composition were introduced in [EM90] but we additionally want to allow component verification based on export-import implications. Import-Export implications relate sentences of the import stating what the component requires to sentences of the export stating what the component guarantees. The main result of this paper is the compatibility of import-export implications are compatible with the partial composition. The second part illustrates how this abstract concept can be instantiated to Petri net systems

Petri net modules in the transformation-based component framework

AbstractComponent-based software engineering needs to be backed by thorough formal concepts and modeling techniques. This paper combines two concepts introduced independently by the two authors in previous papers. On one hand, the concept of Petri net modules introduced at IDPT 2002 in Padberg [J. Padberg, Petri net modules, Journal on Integrated Design and Process Technology 6 (4) (2002) 105–120], and on the other hand a generic component framework for system modeling introduced at FASE 2002 in Ehrig et al. [H. Ehrig, F. Orejas, B. Braatz, M. Klein, M. Piirainen, A generic component concept for system modeling, in: Proceedings of FASE ’02, Lecture Notes in Computer Science, vol. 2306, Springer, 2002]. First we develop a categorical formalization of the transformation based approach to components that is based on pushouts. This is the frame in which we show that Petri net modules can be considered as an instantiation of the generic component framework. This allows applying the transformation based semantics and compositionality result of the generic framework to Petri net modules. In addition to general Petri net modules we introduce Petri net modules preserving safety properties which can be considered as another instantiation of pushout based formalization of the generic framework

Towards Model Checking Reconfigurable Petri Nets using Maude

This paper introduces an approach to model checking of reconfigurable Petri nets. The main task is to flatten the two levels of dynamic behavior that reconfigurable nets provide, the firing of transitions on the one hand and the transformation of the nets on the other hand. We show how to translate a reconfigurable net into  Maude modules. Maude's LTL model-checker is then used to verify properties of these modules

Non-Deterministic Matching Algorithm for Net Transformations

Modeling and simulating dynamic systems require to represent their processes and the system changes within one model. To that effect, reconfigurable Petri nets consist of a  place/transition net and a set of rules that can  modify the Petri net. The application of a rule is based on finding a suitable match of the rule in the given net. This match is an isomorphic  subnet that  has to be located meeting  requirements of the rule application as well as the simulation. In this paper a non-deterministic algorithm is presented for the matching in reconfigurable Petri nets. It is an extension of the VF2 algorithm for graph (sub-)isomorphisms. We show that this extension is correct and complete.   Non-determinism  ensures that during simulation different matches can be found for  each transformation step and is hence crucial for the simulation. But non-determinism has not been present in the VF2 algorithm. For the matching algorithm non-determinism is proven

Reconfigurable Open Algebraic High-Level Systems

In this paper reconfigurable open algebraic high-level (AHL) systems are introduced as an extension of AHL systems [PER95]. In addition to the integration of data structures open places and communicating transitions allow modelling reactive behavior as communication with their environment. Reconfigurable open AHL systems are defined that comprise rules and transformations of these nets. Formally they are an instance of weak adhesive HLR systems [EP06] and so yield the same results. Moreover, a case study is presented that demonstrates the practical need for reconfigurable open AHL systems