A translation apparatus is provided which comprises: an inputting section for inputting a source document in a natural language; a layout analyzing section for analyzing layout information including cascade information, itemization information, numbered itemization information, labeled itemization information and separator line information in the source document inputted by the inputting section and specifying a translation range on the basis of the layout information; a translation processing section for translating a source document text in the specified translation range into a second language; and an outputting section for outputting a translated text provided by the translation processing section.

Automated Planning: Theory and Practice.

Petri nets, as a graphical and mathematical tool, provide a uniform environment for modelling, formal analysis, and design of discrete event systems. The main objective of this paper is to introduce the fundamental concepts of Petri nets to researchers and practitioners, both from academia and industry, who are involved in the work in the areas of modelling and analysis of industrial types of systems, as well as those who may potentially be involved in these areas. The paper begins with an overview of applications of Petri nets, mostly industrial ones. Then, it proceeds with a description of Petri nets, properties, and analysis methods. The discussion of properties is put in the context of industrial applications. The analysis methods are illustrated using an example of a simple robotic assembly system. The performance analysis, using Petri nets, is discussed for deterministic and stochastic Petri nets. The presented techniques are illustrated by examples representing simple production systems. In addition, the paper introduces high-level Petri nets, fuzzy Petri nets, and temporal Petri nets. This is done in the context of application prospects. The paper also briefly discusses some of the reasons restricting the use of Petri nets, mostly, to academic institutions. >

/pdf/petri-nets-and-industrial-applications-a-tutorial-2z7do95d63.pdf

Petri nets and industrial applications: A tutorial

Structure and interpretation of computer programs

This paper is about better engineering of cyber-physical systems (CPSs) through better models. Deterministic models have historically proven extremely useful and arguably form the kingpin of the industrial revolution and the digital and information technology revolutions. Key deterministic models that have proven successful include differential equations, synchronous digital logic and single-threaded imperative programs. Cyber-physical systems, however, combine these models in such a way that determinism is not preserved. Two projects show that deterministic CPS models with faithful physical realizations are possible and practical. The first project is PRET, which shows that the timing precision of synchronous digital logic can be practically made available at the software level of abstraction. The second project is Ptides (programming temporally-integrated distributed embedded systems), which shows that deterministic models for distributed cyber-physical systems have practical faithful realizations. These projects are existence proofs that deterministic CPS models are possible and practical.

The past, present and future of cyber-physical systems: a focus on models.

In this paper we study the use of Sequence Diagrams and Statecharts of the Unified Modeling Language (UML) for the validation and the performance evaluation of systems. We assume that the system is specified as a set of Statecharts and that Sequence Diagrams are used to represent "executions of interest". UML lacks a formal semantics and hence it is not possible to apply, directly, mathematical techniques on UML models for system validation. To reach this goal we propose an automatic translation of Statecharts and Sequence Diagrams into Generalized Stochastic Petri Nets, and a composition of the resulting net models suitable for reaching a given analysis goal. The translation into Petri nets is based on the abstract syntax of the UML Collaborations and of the State Machines packages (from which Sequence Diagrams and Statecharts are derived) and the construction of the complete model heavily uses compositionality.

From UML sequence diagrams and statecharts to analysable petri net models

An attempt is made to introduce imprecision and uncertainty within Petri net theory in order to take into account abnormal events as well as the normal operation for the control and monitoring of flexible manufacturing systems. The uncertainty and imprecision concepts are introduced through a modification of the marking of a Petri net with objects and through time handling. The approach is based on the association of fuzzy enabling duration with the transition which results in attaching a fuzzy firing date to the transition. Some examples of possible use are presented. >

Monitoring manufacturing systems by means of Petri nets with imprecise markings

After having described the importance and the complexity of monitoring Flexible Manufacturing Systems, this paper shows the interest of introducing uncertainty and imprecision within Petri net based models. These two concepts are then introduced through a modification of the marking of a Petri net with Objects, and of its interpretation (external conditions associated with the transitions). It is shown how, in some cases, uncertainty is propagated and how, sometimes, it is possible to go back to certainty. Finally, an illustrative example is described.

Petri nets with uncertain markings

This paper presents the possibilistic Petri net model which combines possibility logic with Petri nets with objects. The main feature of this model is to allow one to reason about the aspects of uncertainty and change in dynamic discrete event systems. The paper presents relevant concepts of Petri nets with objects and possibility logic and how imprecision and vagueness are introduced in the marking of a Petri net with objects. The marking of a net is imprecise, or in a more general way, fuzzy, in order to represent an ill-known knowledge about a system state. A new marking updating according to the fuzzy marking such defined is also discussed. An example of shop door monitoring is presented that illustrates our approach.

Possibilistic Petri nets

J. Cardoso, H. Camargo: Preface.- Introductory Sections: R. Valette, B. Pradin-Chezalviel, F. Girault: An Introduction to Petri Net Theory M. Fedrizzi, J. Kacprzyk: A Brief Introduction to Fuzzy Sets and Fuzzy Systems D. Dubois, H. Prade: A Brief Introduction to Possibility Theory and Its Use for Processing Fuzzy Temporal Information.- Fuzziness in Petri Nets: Various Aspects: C.G. Looney: Fuzzy Petri Nets for Rule-Based Decisionmaking T. Murata, T. Suzuki, S.M. Shatz: Fuzzy-Timing High-Level Petri Nets for Time-Critical Systems J. Cardoso: Time Fuzzy Petri Nets L. Kunzle, R. valette, B. Pradin-Chezalviel: Temporal Reasoning in Fuzzy Time Petri Nets A. Bugrin, P. Carinena, P. Felix, S. Barro: Reasoning with Fuzzy Temporal Rules on Petri Nets S.-M. Chen: Knowledge Base Verification Using Fuzzy Petri Nets L. Gomes: Fuzzy Modelling for Reactive Real-Time Systems Control Using Reactive Petri Nets H. Camargo: The design of Knowledge Bases through Hierarchical Fuzzy Petri Nets W. Pedrycz, J.F. Peters: Learning in Fuzzy Petri Nets: Concepts and Calibration Methodology A. Fay, E. Schnieder: Fuzzy Petri Nets for Knowledge Modelling in Expert Systems.

Fuzziness in Petri Nets

This work describes a framework for distributed simulation of cyber-physical systems (CPS). Modern CPS comprise large numbers of heterogeneous components, typically designed in very different tools and languages that are not or not easily compose able. Evaluating such large systems requires tools that integrate all components in a systematic, well-defined manner. This work leverages existing frameworks to facilitate the integration offers validation by simulation. A framework for distributed simulation is the IEEE High-Level Architecture (HLA) compliant tool CERTI, which provides the infrastructure for co-simulation of models in various simulation environments as well as hardware components. We use CERTI in combination with Ptolemy II, an environment for modeling and simulating heterogeneous systems. In particular, we focus on models of a CPS, including the physical dynamics of a plant, the software that controls the plant, and the network that enables the communication between controllers. We describe the Ptolemy extensions for the interaction with HLA and demonstrate the approach on a flight control system simulation.

/pdf/distributed-simulation-of-heterogeneous-and-real-time-3al63d2lzb.pdf

Janette Cardoso

Papers

Monitoring manufacturing systems by means of Petri nets with imprecise markings

Petri nets with uncertain markings

Possibilistic Petri nets

Fuzziness in Petri Nets

Distributed Simulation of Heterogeneous and Real-Time Systems