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Petrify: a tool for manipulating concurrent specifications and . . .
"... Petrify is a tool for (1) manipulating concurrent specifications and (2) synthesis and optimization of asynchronous control circuits. Given a Petri Net (PN), a Signal Transition Graph (STG), or a Transition System (TS) 1 it (1) generates another PN or STG which is simpler than the original descripti ..."
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Cited by 213 (34 self)
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Petrify is a tool for (1) manipulating concurrent specifications and (2) synthesis and optimization of asynchronous control circuits. Given a Petri Net (PN), a Signal Transition Graph (STG), or a Transition System (TS) 1 it (1) generates another PN or STG which is simpler than the original description and (2) produces an optimized netlist of an asynchronous controller in the target gate library while preserving the specified inputoutput behavior. Given a specification petrify provides a designer with a netlist of an asynchronous circuit and a PNlike description of the circuit behavior in terms of events and ordering relations between events. The latter ability of backannotating to the specification level helps the designer to control the design process. For transforming a specification petrify performs a token flow analysis of the initial PN and produces a transition system (TS). In the initial TS, all transitions with the same label are considered as one event. The TS is then transformed and transitions relabeled to fulfill the conditions required to obtain a safe irredundant PN. For synthesis of an asynchronous implementation petrify performs state assignment by solving the Complete State Coding problem. State assignment is coupled with logic minimization and speedindependent technology mapping to a target library. The final netlist is guaranteed to be speedindependent, i.e., hazardfree under any distribution of gate delays and multiple input changes satisfying the initial specification. The tool has been used for synthesis of PNs and PNs composition [10], synthesis [7, 9, 8] and resynthesis [29] of asynchronous controllers and can be also applied in areas related with the analysis of concurrent programs. This paper provides an overview of petrify and the theory behind its main functions.
A.: Deriving petri nets from finite transition systems
 Computers, IEEE Transactions on
, 1998
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BRIDGING THE GAP BETWEEN BUSINESS MODELS AND WORKFLOW SPECIFICATIONS
 INTERNATIONAL JOURNAL OF COOPERATIVE INFORMATION SYSTEMS
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Synthesizing Petri nets from statebased models
, 1995
"... This paper presentsa method to synthesize labeled Petri nets from statebased models. Although statebased models (such as Finite State Machines) are a powerful formalism to describe the behavior of sequential systems,they cannot explicitly express the notions of concurrency, causality and conflict. ..."
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Cited by 40 (17 self)
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This paper presentsa method to synthesize labeled Petri nets from statebased models. Although statebased models (such as Finite State Machines) are a powerful formalism to describe the behavior of sequential systems,they cannot explicitly express the notions of concurrency, causality and conflict. Petri nets can naturally capture these notions. The proposed method in based on deriving an Elementary Transition System (ETS) from a specification model. Previous work has shown that for any ETS there exists a Petri net with minimum transition count (one transition for each label) with a reachability graph isomorphic to the original ETS. This paper presents the first known approach to obtain an ETS from a nonelementary TS and derive a placeirredundant Petri net. Furthermore, by imposing constraints on the synthesis method, different classes of Petri nets can be derived from the same reachability graph (pure, free choice, unique choice). This method has been implemented and efficiently applied in different frameworks: Petri net composition, synthesis of Petri nets from asynchronous circuits, and resynthesis of Petri nets. 1
A Light Workflow Management System Using Simple Process Models
"... Workflow management systems are considered a hot technology. Nevertheless, up to now they have not had the diffusion other packages such as productivity tools, email systems and groupware platforms have. We believe that this fact is due to the many limitations of current workflow technology (weak s ..."
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Cited by 37 (0 self)
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Workflow management systems are considered a hot technology. Nevertheless, up to now they have not had the diffusion other packages such as productivity tools, email systems and groupware platforms have. We believe that this fact is due to the many limitations of current workflow technology (weak support for changes; complex exception handling mechanisms; limited openness to and integrability with other system components; ...) and that radically new workflow management systems should be designed and developed in order to offer adequate products to the market. In this paper we outline the main innovative features of the workflow management component of the MILANO system making it highly flexible and adaptable. A particular attention is paid to its modelling framework which is based on a class of net systems well supported by efficient algorithms and to the services it offers to both workflow designers and actors. The most relevant aspects of the MILANO workflow management system are also illustrated through a realistic example.
A Relational Model of NonDeterministic Dataflow
 In CONCUR'98, volume 1466 of LNCS
, 1998
"... . We recast dataflow in a modern categorical light using profunctors as a generalisation of relations. The well known causal anomalies associated with relational semantics of indeterminate dataflow are avoided, but still we preserve much of the intuitions of a relational model. The development fits ..."
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Cited by 27 (13 self)
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. We recast dataflow in a modern categorical light using profunctors as a generalisation of relations. The well known causal anomalies associated with relational semantics of indeterminate dataflow are avoided, but still we preserve much of the intuitions of a relational model. The development fits with the view of categories of models for concurrency and the general treatment of bisimulation they provide. In particular it fits with the recent categorical formulation of feedback using traced monoidal categories. The payoffs are: (1) explicit relations to existing models and semantics, especially the usual axioms of monotone IO automata are read off from the definition of profunctors, (2) a new definition of bisimulation for dataflow, the proof of the congruence of which benefits from the preservation properties associated with open maps and (3) a treatment of higherorder dataflow as a biproduct, essentially by following the geometry of interaction programme. 1 Introduction A fundament...
Models of Computation for Embedded System Design
 in SystemLevel Synthesis
, 1998
"... In the near future, most objects of common use will contain electronics to augment their functionality, performance, and safety. Hence, timetomarket, safety, lowcost, and reliability will have to be addressed by any system design methodology. A fundamental aspect of system design is the specificat ..."
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Cited by 26 (0 self)
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In the near future, most objects of common use will contain electronics to augment their functionality, performance, and safety. Hence, timetomarket, safety, lowcost, and reliability will have to be addressed by any system design methodology. A fundamental aspect of system design is the specification process. We advocate using an unambiguous formalism to represent design specifications and design choices. This facilitates tremendously efficiency of specification, formal verification, and correct design refinement, optimization, and implementation. This formalism is often called model of computation. There are several models of computation that have been used, but there is a lack of consensus among researchers and practitioners on the "right" models to use. To the best of our knowledge, there has also been little effort in trying to compare rigorously these models of computation. In this paper, we review current models of computation and compare them within a framework that has been r...
Bisimulation Relations for Dynamical and Control Systems
, 2002
"... In this paper we propose a new equivalence relation for dynamical and control systems called bisimulation. As the name implies this definition is inspired by the fundamental notion of bisimulation introduced by R. Milner for labeled transition systems. It is however, more subtle than its namesake in ..."
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Cited by 24 (9 self)
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In this paper we propose a new equivalence relation for dynamical and control systems called bisimulation. As the name implies this definition is inspired by the fundamental notion of bisimulation introduced by R. Milner for labeled transition systems. It is however, more subtle than its namesake in concurrency theory, mainly due to the fact that here, one deals with relations on manifolds. We further show that the bisimulation relations for dynamical and control systems defined in this paper are captured by the notion of abstract bisimulation of Joyal, Nielsen and Winskel (JNW). This result not only shows that our equivalence notion is on the right track, but also confirms that the abstract bisimulation of JNW is general enough to capture equivalence notions in the domain of continuous systems. We believe that the unification of the bisimulation relation for labeled transition systems and dynamical systems under the umbrella of abstract bisimulation, as achieved in this work, is a first step towards a unified approach to modeling of and reasoning about the dynamics of discrete and continuous structures in computer science and control theory.
An Event Structure Semantics for General Petri Nets
 Theoretical Computer Science
, 1993
"... In this paper we address the following question: What type of event structures are suitable for representing the behaviour of general Petri nets? As a partial answer to this question we define a new class of event structures called local event structures and identify a subclass called ULevent stru ..."
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Cited by 24 (1 self)
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In this paper we address the following question: What type of event structures are suitable for representing the behaviour of general Petri nets? As a partial answer to this question we define a new class of event structures called local event structures and identify a subclass called ULevent structures. We propose that ULevent structures are appropriate for capturing the behaviour of general Petri nets. Our answer is a partial one in that in the proposed event structure semantics, autoconcurrency is filtered out from the behaviour of Petri nets. It turns out that this limited event structure semantics for Petri nets is nevertheless a nontrivial and conservative extension of the (prime) event structure semantics of 1safe Petri nets provided in [NPW]. We also show that the strong relationship between prime event structures and 1safe Petri nets established in a categorical framework in [W3] can be extended to the present setting, provided we restrict our attention to the subclass ...