http://www.biblioteca.uma.es/bbldoc/tesisuma/16638657.pdf

Maude: specification and programming in rewriting logic

Cyberphysical systems (CPSs) are new class of engineered systems that offer close interaction between cyber and physical components. The field of CPS has been identified as a key area of research, and CPSs are expected to play a major role in the design and development of future systems. In this paper, we survey recent advancements made in the development and applications of CPSs. We classify the existing research work based on their characteristics and identify the future challenges. We also discuss the examples of prototypes of CPSs. The aim of this survey is to enable researchers and system designers to get insights into the working and applications of CPSs and motivate them to propose novel solutions for making wide-scale adoption of CPS a tangible reality.

Design Techniques and Applications of Cyberphysical Systems: A Survey

The new paradigm of dynamic spectrum access (DSA) networks aims to provide opportunistic access to large parts of the underutilized spectrum. The majority of research in this area has focused on free-for-all, uncoordinated access methods common in ad-hoc military applications (Horne, W. 2003; Leaves, P. et al., 2002; Lehr, W. et al., 2002; Schafer, D.J.; To/spl uml/njes, R., 2002). We argue that a simpler pragmatic approach that offers coordinated, spatially aggregated spectrum access via a regional spectrum broker is more attractive in the immediate future. We first introduce two new concepts, coordinated access band (CAB) and statistically multiplexed access (SMA), to the spectrum. We describe their implementation in the new DIMSUMnet (dynamic intelligent management of spectrum for ubiquitous mobile-access network) architecture consisting of four elements: base stations; clients; a radio access network manager (RAN-MAN) that obtains spectrum leases; a per-domain spectrum broker that controls spectrum access. We also discuss in detail various issues in the design of spectrum brokers and spectrum allocation policies and algorithms.

DIMSUMnet: new directions in wireless networking using coordinated dynamic spectrum

This is probably the most popular design of experiments (DOE) book. It is unquestionably the leading DOE book in industry. So I am excepting it from the usual disdain I show for the  fth edition (5E) of any book, even though it follows the fourth edition (4E) by only four years. See Grice (2000) for a report on the 4E. Very likely this book bears little resemblance to the  rst edition way back in the 1970s. The author has taken particular care with this latest edition to reorganize the book to be consistent with modern DOE practice rather than classical DOE presentation. The primary change has been to move the chapters on regression modeling and response surface methods forward in the book. In the 4E these were the last two chapters in the book. In the 5E they follow the chapters on factorial and fractional factorial designs. Three chapters on “other designs” now close out the book. This certainly gives the book a better  ow for industry short courses. Perhaps these will simply be referenced as arcane methods in the sixth edition! Other production values in the book also continue to improve. There are many high-quality graphical displays. There is much use of printouts from Minitab and Design-Expert. A student version of Design-Export comes with the book. There is also an instructor’s CD-ROM with supplemental material to make the book suitable for more advanced courses. There is the now-essential Web site that has more information to help students and instructors. Perhaps if I were teaching DOE for master’s-level statisticians, the recent book by Dean and Voss (1999), reviewed by Amidan (2000), would be my choice. However, for most other audiences this is the complete DOE book. Industrial statisticians should get a copy of the new version and ensure its exposure to the relevant people in their organization.

Introduction to the Practice of Statistics

Control of Discrete-event Systems provides a survey of the most important topics in the discrete-event systems theory with particular focus on finite-state automata, Petri nets and max-plus algebra. Coverage ranges from introductory material on the basic notions and definitions of discrete-event systems to more recent results. Special attention is given to results on supervisory control, state estimation and fault diagnosis of both centralized and distributed/decentralized systems developed in the framework of the Distributed Supervisory Control of Large Plants (DISC) project. Later parts of the text are devoted to the study of congested systems though fluidization, an over approximation allowing a much more efficient study of observation and control problems of timed Petri nets. Finally, the max-plus algebraic approach to the analysis and control of choice-free systems is also considered. Control of Discrete-event Systems provides an introduction to discrete-event systems for readers that are not familiar with this class of systems, but also provides an introduction to research problems and open issues of current interest to readers already familiar with them. Most of the material in this book has been presented during a Ph.D. school held in Cagliari, Italy, in June 2011. This book constitutes the refereed proceedings of the Third International Workshop on Tools and Algorithms for the Construction and Analysis of Systems, TACAS '97, held in Enschede, The Netherlands, in April 1997. The book presents 20 revised full papers and 5 tool demonstrations carefully selected out of 54 submissions; also included are two extended abstracts and a full paper corresponding to invited talks. The papers are organized in topical sections on space reduction techniques, tool demonstrations, logical techniques, verification support, specification and analysis, and theorem proving, model checking and applications. The refereed proceedings of the 24th International Conference on Applications and Theory of Petri Nets, ICATPN 2003, held in Eindhoven, The Netherlands, in June 2003. The 25 revised full papers presented together with 6 invited contributions were carefully reviewed and selected from 77 submissions. All current issues on research and development in the area of Petri nets are addressed, in particular concurrent systems design and analysis, model checking, networking, business process modeling, formal methods in software engineering, agent systems, systems specification, systems validation, discrete event systems, protocols, and prototyping. The contents of this volume are application oriented. The volume contains a de tailed presentation of 19 applications of CP-nets, covering a broad range of ap plication areas. Most of the projects have been carried out in an industrial set ting.

Coloured Petri Nets Basic Concepts, Analysis Methods and Practical Use

We propose rewriting logic as a unifying framework for a wide range of Petri nets models. We treat in detail place/transition nets and important extensions of the basic model by individual tokens, test arcs, and time. Based on the idea that "Petri nets are monoids" suggested by Meseguer and Montanari we define a rewriting semantics that maps place/transition nets into rewriting logic specifications. We furthermore generalize this result to a general form of algebraic net specifications subsuming also colored Petri nets as a special case. The soundness and completeness results we state relate the commutative process semantics of Petri nets proposed by Best and Devillers to the model-theoretic semantics of rewriting logic in the sense of natural isomorphisms between suitable functors. In addition we show how place/transition nets with test arcs and timed Petri nets can be equipped with a rewriting semantics and discuss how other extensions can be treated along similar lines. Beyond the conceptual unification of quite different kinds of Petri nets within a single framework, the rewriting semantics can provide a guide for future extensions of Petri nets and help to cope with the growing diversity of models in this field. On the practical side, a major application of the rewriting semantics is its use as a logical and operational representation of Petri net models for formal verification and for the efficient execution and analysis using a rewriting engine such as Maude, which also allows us to specify different execution and analysis strategies in the same rewriting logic language by means of reflection.

https://fldit-www.cs.uni-dortmund.de/~peter/RewLogPetri.pdf

Rewriting Logic as a Unifying Framework for Petri Nets

Given the different perspectives from which a complex software system has to be analyzed, the multiplicity of formalisms is unavoidable. This poses two important technical challenges: how to rigorously meet the need to interrelate formalisms, and how to reduce the duplication of effort in tool and specification building across formalisms. These challenges could be answered by adequate formal meta-tools that, when given the specification of a formal inference system, generate an efficient inference engine, and when given a specification of two formalisms and a translation, generate an actual translator between them. Similarly, module composition operations that are logic-independent, but that at present require costly implementation efforts for each formalism, could be provided for logics in general by module algebra generator meta-tools. The foundations of meta-tools of this kind can be based on a metatheory of general logics. Their actual design and implementation can be based on appropriate logical frameworks having efficient implementations. This paper explains how the reflective logical framework of rewriting logic can be used, in conjunction with an efficient reflective implementation such as the Maude language, to design formal meta-tools such as those described above. The feasibility of these ideas and techniques has been demonstrated by a number of substantial experiments in which new formal tools and new translations between formalisms, efficient enough to be used in practice, have been generated.

/pdf/maude-as-a-formal-meta-tool-t5x02ps223.pdf

Maude as a Formal Meta-tool

In this paper, we address the role of middleware in enabling robust and resilient cyber-physical systems (CPSs) of the future. In particular, we will focus on how adaptation services can be used to improve dependability in instrumented cyber-physical systems based on the principles of “computational reflection.” CPS environments incorporate a variety of sensing and actuation devices in a distributed architecture; such a deployment is used to create a digital representation of the evolving physical world and its processes for use by a broad range of applications. CPS applications, in particular, mission critical tasks, must execute dependably despite disruptions caused by failures and limitations in sensing, communications, and computation. This paper discusses a range of applications, their reliability needs, and potential dependability holes that can cause performance degradation and application failures. In particular, we distinguish between the notion of infrastructure and information dependability and illustrate the need to formally model and reason about a range of CPS applications and their dependability needs. Formal methods based tools can help us design meaningful cross-layer adaptation techniques at different system layers of the CPS environment and thereby achieve end-to-end dependability at both the infrastructure and information levels.

/pdf/resilient-dependable-cyber-physical-systems-a-middleware-ge9gtq8v4q.pdf

Resilient dependable cyber-physical systems: a middleware perspective

We argue for a policy-based approach to increase spectrum availability. To this extend, we briefly summarize a new language for expressing policies that allow opportunistic spectrum access. A Policy Reasoner that reasons about these policies can be used with cognitive radios to guarantee policy- specified behaviors while allowing spectrum sharing. We present our policy reasoner design and we evaluated the reasoner in a demonstration. We describe the policies used in that demonstration and the results of the evaluation.

/pdf/a-policy-engine-for-spectrum-sharing-9gvj7wgqmg.pdf

Mark-Oliver Stehr

Papers

Rewriting Logic as a Unifying Framework for Petri Nets

Maude as a Formal Meta-tool

Resilient dependable cyber-physical systems: a middleware perspective

A Policy Engine for Spectrum Sharing

CINNI - A Generic Calculus of Explicit Substitutions and its Application to λ- ς- and π-Calculi