43,873 research outputs found

    An approach to rollback recovery of collaborating mobile agents

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    Fault-tolerance is one of the main problems that must be resolved to improve the adoption of the agents' computing paradigm. In this paper, we analyse the execution model of agent platforms and the significance of the faults affecting their constituent components on the reliable execution of agent-based applications, in order to develop a pragmatic framework for agent systems fault-tolerance. The developed framework deploys a communication-pairs independent check pointing strategy to offer a low-cost, application-transparent model for reliable agent- based computing that covers all possible faults that might invalidate reliable agent execution, migration and communication and maintains the exactly-one execution property

    Agent oriented AmI engineering

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    Towards alignment of architectural domains in security policy specifications

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    Large organizations need to align the security architecture across three different domains: access control, network layout and physical infrastructure. Security policy specification formalisms are usually dedicated to only one or two of these domains. Consequently, more than one policy has to be maintained, leading to alignment problems. Approaches from the area of model-driven security enable creating graphical models that span all three domains, but these models do not scale well in real-world scenarios with hundreds of applications and thousands of user roles. In this paper, we demonstrate the feasibility of aligning all three domains in a single enforceable security policy expressed in a Prolog-based formalism by using the Law Governed Interaction (LGI) framework. Our approach alleviates the limitations of policy formalisms that are domain-specific while helping to reach scalability by automatic enforcement provided by LGI

    Transatlantic Issues in Electronic Commerce

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    The global and dynamic e-commerce marketplace will increasingly impact the nature of national and international economic and government relations. This paper highlights three areas where the United States and European Union (EU) governments differ in their approaches as to how best to serve their domestic constituencies: treatment of trade flows, approach to tax regimes, manner of protecting personal data. Because the Internet marketplace is global but policy jurisdictions remain local, policy conflicts can develop. Policymakers on both sides need to harness technology and promote incentives for the private sector to help solve problems caused by the jurisdictional overlap. In addition to cross-border jurisdictional overlap, problems within a country can develop from issue convergence and policy overlap. That is, because the e-commerce marketplace is so integrated, the policy toward handling one issue, even within the national context, has implications for the policy set that is available to policymakers on other issues. Therefore, policies within a country must be more carefully meshed with each other with an eye toward consistency in the face of the forces of electronic commerce.transatlantic issues, electronic commerce

    Specifying and analysing reputation systems with coordination languages

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    Reputation systems are nowadays widely used to support decision making in networked systems. Parties in such systems rate each other and use shared ratings to compute reputation scores that drive their interactions. The existence of reputation systems with remarkable differences calls for formal approaches to their analysis. We present a verification methodology for reputation systems that is based on the use of the coordination language Klaim and related analysis tools. First, we define a parametric Klaim specification of a reputation system that can be instantiated with different reputation models. Then, we consider stochastic specification obtained by considering actions with random (exponentially distributed) duration. The resulting specification enables quantitative analysis of properties of the considered system. Feasibility and effectiveness of our proposal is demonstrated by reporting on the analysis of two reputation models
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