Negative Application Conditions for Reconfigurable Algebraic High-Level Systems

This paper introduces negative application conditions for reconfigurable algebraic high-level systems. These are algebraic high-level systems, i.e. algebraic high-level nets with an initial marking, together with a set of rules for changing the system dynamically. Negative application conditions are a control structure for restricting the application of a rule if a certain structure is present. The use of negative application conditions is motivated in a short example. Subsequently, the underlying theory is sketched and the most significant results are presented. Finally, the example is resumed and the main results and their usefulness within the example are discussed

Reconfigurable Petri Systems with Negative Application Conditions

Diese Arbeit führt negative Anwendungsbedingungen (NACs) für verschiedene Typen von rekonfigurierbaren Petri Systemen ein. Dies sind Petri Systeme mit einer Menge von Transformationsregeln, die eine dynamische Veränderung des Petri Systems ermöglichen. Negative Anwendungsbedingungen sind eine Kontrollstruktur um die Anwendung einer Regel zu verbieten, wenn eine bestimmte Struktur vorhanden ist. Wie in [Lam07] und [LEOP08] vorgestellt, sind schwach adhäsive HLR Kategorien mit negativen Anwendungsbedingungen schwach adhäsive HLR Kategorien mit drei zusätzlichen, ausgezeichneten Morphismenklassen und einigen zusätzlichen Eigenschaften. Diese Eigenschaften werden benötigt, um Ergebnisse wie das Lokale Church-Rosser Theorem, das Parallelismustheorem, das Vollständigkeitstheorem der kritischen Paare, das Nebenläufigkeitstheorem, das Einbettungs- und das Erweiterungstheorem und das Lokale Konfluenz Theorem für die Benutzung mit negativen Anwendungsbedingungen zu verallgemeinern. Das Hauptziel dieser Arbeit besteht darin nachzuweisen, dass die Kategorien PTSys der P/T Systeme, AHLNet der AHL Netze, AHLSystems der AHL Systeme und PTSys(L) der L-gelabelten P/T Systeme schwach adhäsive HLR Kategorien mit negativen Anwendungsbedingungen sind. Dafür werden diese Kategorien formal eingeführt und die dafür benötigten Eigenschaften detailliert bewiesen. Zusätzlich wird die praktische Anwendung der erzielten Ergebnisse in Form von Fallstudien dargelegt.This thesis introduces negative application conditions (NACs) for varied kinds of reconfigurable Petri systems. These are Petri systems together with a set of transformation rules that allow changing the Petri system dynamically. Negative applications are a control structure for restricting the application of a rule if a certain structute is present. As introduced in [Lam07] and [LEOP08], (weak) adhesive high-level replacement (HLR) categories with negative application conditions are (weak) adhesive HLR categories with three additional distinguished morphism classes and some additional properties. These properties are required for generalizing results like Local Church- Rosser Theorem, Parallelism Theorem, Completeness Theorem of Critical Pairs, Concurrency Theorem, Embedding and Extension Theorem and Local Confluence Theorem for the use of negative application conditions. The main goals of this thesis are proving that the categories PTSys of P/T systems, AHLNet of algebraic high-level (AHL) nets, AHLSystems of AHL systems and PTSys(L) of L-labeled P/T systems are weak adhesive HLR categories with negative application conditions. Therefore, these categories are formally introduced and the required properties are proven in detail. Additionally, the practical application of the achieved results is presented in form of case studies

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

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

Formal Modeling of Communication Platforms using Reconfigurable Algebraic High-Level Nets

Communication nowadays is based on communication platforms like Skype, Facebook, or SecondLife. The formal modeling and analysis of communication platforms poses considerable challenges, namely highly dynamic structures and complex behavior. Since most of the well-known formal modeling approaches are adequate only for specific aspects of communication platforms, in this paper we introduce the approach of reconfigurable algebraic high-level nets with individual tokens and show in our case study Skype that this approach is adequate for modeling the main aspects and features of communication platforms

Negative Application Conditions for Reconfigurable Place/Transition Systems

This paper introduces negative application conditions for reconfigurable place/transition nets. These are Petri nets together with a set of rules that allow changing the net and its marking dynamically. Negative application conditions are a control structure that prohibits the application of a rule if certain structures are already existent. We motivate the use of negative application conditions in a short example. Subsequently the underlying theory is sketched and the results – concerning parallelism, concurrency and confluence – are presented. Then we resume the example and explicitly discuss the main results and their usefulness within the example

ReConNet: A Tool for Modeling and Simulating with Reconfigurable Place/Transition Nets

In this contribution we present a tool for modeling and simulation with reconfigurable Petri nets. Taking the idea of algebraic graph transformations to marked Petri nets we obtain Petri nets whose net structure can be changed dynamically. The rule-based change of the net structure enables the adequate modeling of complex, dynamic structures as for example of  the scenarios of the Living Place Hamburg. The tool \reconnet \ uses decorated  place/transition nets that are extended by various annotations. Especially, they  have transition labels that may change when the transition fires. The  transformation approach is based on the well-known algebraic transformation approach, but here we use a variant, namely the cospan approach, that inverts the relation between  left- and right-hand sides and interface in the  rules

Independence Analysis of Firing and Rule-based Net Transformations in Reconfigurable Object Nets

The main idea behind Reconfigurable Object Nets (RONs) is to support the visual specification of controlled rule-based net transformations of place/transition nets (P/T nets). RONs are high-level nets with two types of tokens: object nets (place/transition nets) and net transformation rules (a dedicated type of graph transformation rules). Firing of high-level transitions may involve firing of object net transitions, transporting object net tokens through the high-level net, and applying net transformation rules to object nets, e.g. to model net reconfigurations. A visual editor and simulator for RONs has been developed as a plug-in for ECLIPSE using the ECLIPSE Modeling Framework (EMF) and Graphical Editor Framework (GEF) plug-ins. The problem in this context is to analyze under which conditions net transformations and token firing can be executed in arbitrary order. This problem has been solved formally in a previous paper. In this contribution we present an extension of our RON tool which implements the analysis of conflicts between parallel enabled transitions, between parallel applicable net transformation rules (Church-Rosser property), and between transition firing and net transformation steps. The conflict analysis is applied to a RON simulating a distributed producer-consumer system

Fast Hardware Implementations of Static P Systems

In this article we present a simulator of non-deterministic static P systems using Field Programmable Gate Array (FPGA) technology. Its major feature is a high performance, achieving a constant processing time for each transition. Our approach is based on representing all possible applications as words of some regular context-free language. Then, using formal power series it is possible to obtain the number of possibilities and select one of them following a uniform distribution, in a fair and non-deterministic way. According to these ideas, we yield an implementation whose results show an important speed-up, with a strong independence from the size of the P system.Ministry of Science and Innovation of the Spanish Government under the project TEC2011-27936 (HIPERSYS)European Regional Development Fund (ERDF)Ministry of Education of Spain (FPU grant AP2009-3625)ANR project SynBioTI

Automating the transformation-based analysis of visual languages

The final publication is available at Springer via http://dx.doi.org/10.1007/s00165-009-0114-yWe present a novel approach for the automatic generation of model-to-model transformations given a description of the operational semantics of the source language in the form of graph transformation rules. The approach is geared to the generation of transformations from Domain-Specific Visual Languages (DSVLs) into semantic domains with an explicit notion of transition, like for example Petri nets. The generated transformation is expressed in the form of operational triple graph grammar rules that transform the static information (initial model) and the dynamics (source rules and their execution control structure). We illustrate these techniques with a DSVL in the domain of production systems, for which we generate a transformation into Petri nets. We also tackle the description of timing aspects in graph transformation rules, and its analysis through their automatic translation into Time Petri netsWork sponsored by the Spanish Ministry of Science and Innovation, project METEORIC (TIN2008-02081/TIN) and by the Canadian Natural Sciences and Engineering Research Council (NSERC)