612 research outputs found
Petri net-based approach for web service automation resource coordination
In industrial automation, control systems and mechatronic devices are from
diverse nature, supplied by different manufacturers and made of different
technologies. The adoption of web services principles in an automated
production system satisfies some requirements, namely the interoperability of
such heterogeneous and distributed environments and the basis for flexibility
and reconfigurability. Manufacturing processes require to access resources at
different precedence levels and time instances, but in the other way resources
may also be shared by different processes. A major challenge is then how
individual services may interact, coordinating their activities. Petri nets may be
used to describe complex system behaviour and therefore also applied to
coordinate such systems. The paper introduces a Petri net based approach for the
design, analysis and coordination of systems developed using web services to
represent individual and autonomous resources. For this purpose, it is presented
a Petri nets computational tool to support the design, validation and coordination
of web service based automation systems.info:eu-repo/semantics/publishedVersio
A High-level Petri Net Based Approach for Modeling and Composition of Web Services
AbstractWeb services are modular, self-describing, self-contained and loosely coupled applications, which intercommuni-cate via messages exchanging. The evolution of the internet and the emergence of new technologies like e-business have influenced the use of these last ones, which have become popular. The composition of web services is a topic that attracts the interest of researchers. It offers complex problems process ability even with simple existing web services while cooperating with each other. However, modeling tools and formal techniques for the completion of this task are required.In this paper, we show how simple existing web services can be composed, in order to create a composite service, which offers new features. In this context, we propose an expressive object-oriented Petri net based algebra that succeeds in the complex composition of Web services
Interaction protocols for cross-organisational workflows
Workflow technologies are widely used in industry and commerce to assist in the specification, execution and completion of well defined processes within organisations. As industrial and commercial relations have evolved, based on advances on information and communications technologies, cross-organisational workflow integration has become an important issue. Since organisations can have very different workflows, the creation of compatible workflows so that organisations can collaborate and/or carry out mutual transactions automatically in an integrated fashion can be a very complex and time consuming process. As a consequence, the development of technologies to support the creation and execution of compatible workflows is a most relevant issue. In the present article we introduce the JamSession coordination platform as a tool to implement cross-organisational workflow integration. JamSession is declarative and based on algebraic specification methods, and therefore workflow integration implemented using this platform can profit from formal behavioural analysis, based on which desired features and properties can be verified and/or obtained
Towards a Formal Framework for Mobile, Service-Oriented Sensor-Actuator Networks
Service-oriented sensor-actuator networks (SOSANETs) are deployed in
health-critical applications like patient monitoring and have to fulfill strong
safety requirements. However, a framework for the rigorous formal modeling and
analysis of SOSANETs does not exist. In particular, there is currently no
support for the verification of correct network behavior after node failure or
loss/addition of communication links. To overcome this problem, we propose a
formal framework for SOSANETs. The main idea is to base our framework on the
\pi-calculus, a formally defined, compositional and well-established formalism.
We choose KLAIM, an existing formal language based on the \pi-calculus as the
foundation for our framework. With that, we are able to formally model SOSANETs
with possible topology changes and network failures. This provides the basis
for our future work on prediction, analysis and verification of the network
behavior of these systems. Furthermore, we illustrate the real-life
applicability of this approach by modeling and extending a use case scenario
from the medical domain.Comment: In Proceedings FESCA 2013, arXiv:1302.478
Workshop on Modelling of Objects, Components, and Agents, Aarhus, Denmark, August 27-28, 2001
This booklet contains the proceedings of the workshop Modelling of Objects, Components, and Agents (MOCA'01), August 27-28, 2001. The workshop is organised by the CPN group at the Department of Computer Science, University of Aarhus, Denmark and the "Theoretical Foundations of Computer Science" Group at the University of Hamburg, Germany. The papers are also available in electronic form via the web pages: http://www.daimi.au.dk/CPnets/workshop01
An Automated Framework for BPMN Model Verification Achieving Branch Coverage
BPMN model is used in software development process that the procedural logics of software are described in term of graphical representation. Formal verification using colored Petri net (CPN) can be used to prove whether a designed BPMN model is frees of undesirable properties such as deadlock and unreachable task, and meets user requirements or not. Although there are many researches providing the transformation rules and frameworks for automating and verifying the CPN model, the CPN markings determination covering all execution paths is quite cumbersome. This paper proposes an automated BPMN verification framework that integrates the BPMN modeling tool and the CPN model checker together. The designed BPMN model is transformed into a CPN model and control flow graph (CFG). The CFG is used to create the execution paths and to find the interleaved activities. The interleaved activities are then considered for creating the CPN port places and markings by an applying of the branch coverage testing technique. Behaviors of the CPN model are analyzed by using a state space analysis based on the CPN model and automated markings. Our framework has been implemented as an Eclipse BPMN modeler plugin, and it is tested with the five case studies. The results show that our framework is practical. It can automate the CPN models from the BPMN model and guide the designers regarding the CPN markings determination to achieve branch coverage criteria
Evaluating Resilience of Cyber-Physical-Social Systems
Nowadays, protecting the network is not the only security concern. Still, in cyber security,
websites and servers are becoming more popular as targets due to the ease with which
they can be accessed when compared to communication networks. Another threat in
cyber physical social systems with human interactions is that they can be attacked and
manipulated not only by technical hacking through networks, but also by manipulating
people and stealing users’ credentials. Therefore, systems should be evaluated beyond cy-
ber security, which means measuring their resilience as a piece of evidence that a system
works properly under cyber-attacks or incidents. In that way, cyber resilience is increas-
ingly discussed and described as the capacity of a system to maintain state awareness for
detecting cyber-attacks. All the tasks for making a system resilient should proactively
maintain a safe level of operational normalcy through rapid system reconfiguration to
detect attacks that would impact system performance. In this work, we broadly studied
a new paradigm of cyber physical social systems and defined a uniform definition of it.
To overcome the complexity of evaluating cyber resilience, especially in these inhomo-
geneous systems, we proposed a framework including applying Attack Tree refinements
and Hierarchical Timed Coloured Petri Nets to model intruder and defender behaviors
and evaluate the impact of each action on the behavior and performance of the system.Hoje em dia, proteger a rede não é a única preocupação de segurança. Ainda assim, na
segurança cibernética, sites e servidores estão se tornando mais populares como alvos
devido à facilidade com que podem ser acessados quando comparados às redes de comu-
nicação. Outra ameaça em sistemas sociais ciberfisicos com interações humanas é que eles
podem ser atacados e manipulados não apenas por hackers técnicos através de redes, mas
também pela manipulação de pessoas e roubo de credenciais de utilizadores. Portanto, os
sistemas devem ser avaliados para além da segurança cibernética, o que significa medir
sua resiliência como uma evidência de que um sistema funciona adequadamente sob
ataques ou incidentes cibernéticos. Dessa forma, a resiliência cibernética é cada vez mais
discutida e descrita como a capacidade de um sistema manter a consciência do estado para
detectar ataques cibernéticos. Todas as tarefas para tornar um sistema resiliente devem
manter proativamente um nível seguro de normalidade operacional por meio da reconfi-
guração rápida do sistema para detectar ataques que afetariam o desempenho do sistema.
Neste trabalho, um novo paradigma de sistemas sociais ciberfisicos é amplamente estu-
dado e uma definição uniforme é proposta. Para superar a complexidade de avaliar a
resiliência cibernética, especialmente nesses sistemas não homogéneos, é proposta uma
estrutura que inclui a aplicação de refinamentos de Árvores de Ataque e Redes de Petri
Coloridas Temporizadas Hierárquicas para modelar comportamentos de invasores e de-
fensores e avaliar o impacto de cada ação no comportamento e desempenho do sistema
Reo + mCRL2: A Framework for Model-checking Dataflow in Service Compositions
The paradigm of service-oriented computing revolutionized the field of software engineering. According to this paradigm, new systems are composed of existing stand-alone services to support complex cross-organizational business processes. Correct communication of these services is not possible without a proper coordination mechanism. The Reo coordination language is a channel-based modeling language that introduces various types of channels and their composition rules. By composing Reo channels, one can specify Reo connectors that realize arbitrary complex behavioral protocols. Several formalisms have been introduced to give semantics to Reo. In their most basic form, they reflect service synchronization and dataflow constraints imposed by connectors. To ensure that the composed system behaves as intended, we need a wide range of automated verification tools to assist service composition designers. In this paper, we present our framework for the verification of Reo using the toolset. We unify our previous work on mapping various semantic models for Reo, namely, constraint automata, timed constraint automata, coloring semantics and the newly developed action constraint automata, to the process algebraic specification language of , address the correctness of this mapping, discuss tool support, and present a detailed example that illustrates the use of Reo empowered with for the analysis of dataflow in service-based process models
Reo + mCRL2: A Framework for Model-Checking Dataflow in Service Compositions
The paradigm of service-oriented computing revolutionized the field of software
engineering. According to this paradigm, new systems are composed of existing
stand-alone services to support complex cross-organizational business
processes. Correct communication of these services is not possible without a
proper coordination mechanism. The Reo coordination language is a channel-based
modeling language that introduces various types of channels and their
composition rules. By composing Reo channels, one can specify Reo connectors
that realize arbitrary complex behavioral protocols. Several formalisms have
been introduced to give semantics to Reo. In their most basic form, they
reflect service synchronization and dataflow constraints imposed by connectors.
To ensure that the composed system behaves as intended, we need a wide range of
automated verification tools to assist service composition designers. In this
paper, we present our framework for the verification of Reo using the mCRL2
toolset. We unify our previous work on mapping various semantic models for Reo,
namely, constraint automata, timed constraint automata, coloring semantics and
the newly developed action constraint automata, to the process algebraic
specification language of mCRL2, address the correctness of this mapping,
discuss tool support, and present a detailed example that illustrates the use
of Reo empowered with mCRL2 for the analysis of dataflow in service-based
process models
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