37,926 research outputs found
Structure and Behaviour of Virtual Organisation Breeding Environments
This paper provides an outline of a formal approach that we are developing
for modelling Virtual Organisations (VOs) and their Breeding Environments
(VBEs). We propose different levels of representation for the functional
structures and processes that VBEs and VOs involve, which are independent of
the specificities of the infrastructures (organisational and technical) that
support the functioning of VBEs. This allows us to reason about properties of
tasks performed within VBEs and services provided through VOs without
committing to the way in which they are implemented
WEB service interfaces for inter-organisational business processes an infrastructure for automated reconciliation
For the majority of front-end e-business systems, the assumption of a coherent and homogeneous set of interfaces is highly unrealistic. Problems start in the back-end, with systems characterised by a heterogeneous mix of applications and business processes. Integration can be complex and expensive, as systems evolve more in accordance with business needs than with technical architectures. E-business systems are faced with the challenge to give a coherent image of a diversified reality. Web services make business interfaces more efficient, but effectiveness is a business requirement of at least comparable importance. We propose a technique for automatic reconciliation of the Web service interfaces involved in inter-organisational business processes. The working assumption is that the Web service front-end of each company is represented by a set of WSDL and WSCL interfaces. The result of our reconciliation method is a common interface that all the parties can effectively enforce. Indications are also given on ways to adapt individual interfaces to the common one. The technique was embodied in a prototype that we also present
Security for Grid Services
Grid computing is concerned with the sharing and coordinated use of diverse
resources in distributed "virtual organizations." The dynamic and
multi-institutional nature of these environments introduces challenging
security issues that demand new technical approaches. In particular, one must
deal with diverse local mechanisms, support dynamic creation of services, and
enable dynamic creation of trust domains. We describe how these issues are
addressed in two generations of the Globus Toolkit. First, we review the Globus
Toolkit version 2 (GT2) approach; then, we describe new approaches developed to
support the Globus Toolkit version 3 (GT3) implementation of the Open Grid
Services Architecture, an initiative that is recasting Grid concepts within a
service oriented framework based on Web services. GT3's security implementation
uses Web services security mechanisms for credential exchange and other
purposes, and introduces a tight least-privilege model that avoids the need for
any privileged network service.Comment: 10 pages; 4 figure
Representing Conversations for Scalable Overhearing
Open distributed multi-agent systems are gaining interest in the academic
community and in industry. In such open settings, agents are often coordinated
using standardized agent conversation protocols. The representation of such
protocols (for analysis, validation, monitoring, etc) is an important aspect of
multi-agent applications. Recently, Petri nets have been shown to be an
interesting approach to such representation, and radically different approaches
using Petri nets have been proposed. However, their relative strengths and
weaknesses have not been examined. Moreover, their scalability and suitability
for different tasks have not been addressed. This paper addresses both these
challenges. First, we analyze existing Petri net representations in terms of
their scalability and appropriateness for overhearing, an important task in
monitoring open multi-agent systems. Then, building on the insights gained, we
introduce a novel representation using Colored Petri nets that explicitly
represent legal joint conversation states and messages. This representation
approach offers significant improvements in scalability and is particularly
suitable for overhearing. Furthermore, we show that this new representation
offers a comprehensive coverage of all conversation features of FIPA
conversation standards. We also present a procedure for transforming AUML
conversation protocol diagrams (a standard human-readable representation), to
our Colored Petri net representation
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The systemic implications of constructive alignment of higher education level learning outcomes and employer or professional body based competency frameworks
The past 50 years has seen the development of schemes in higher education, employment and professional work that either identify what people should know and/or what they should be able to do with what they have learned and experienced. Within higher education this is usually equated with the learning outcomes students are expected to achieve at the end of studying a course, module or qualification and increasingly the teaching, learning and assessment strategies of those courses, modules or qualifications are being designed to align with those learning outcomes. In employment, there has been the emergence of job and role specifications setting out the knowledge and skills required of incumbent and recruits alike. Where professional bodies confer (often statutorily recognised) status in employment sectors they also increasingly set out their expectations of members through competency frameworks. This paper explores the varied relationships between these three means of measuring knowledge and skills within people including the nature of the knowledge and skills being measured as well as the specificity of the knowledge and skills being measured, using the case study of environmental management in the UK. It then argues that there needs to be a more constructive alignment between these three forms of measurement, achieved through a dynamic conversation between all concerned, but also that such alignment needs both to recognise the importance of less tangible âsystems thinkingâ abilities alongside the more tangible âtechnicalâ and âmanagerialâ abilities and that some abilities emerge from the trajectories of praxis and cannot readily be specified as an outcome in advance
Policy-driven planning in coalitions - A case study
(c)IFAAMASPeer reviewedPostprin
Detection and resolution of normative conflicts in multi-agent systems : a literature survey
Peer reviewedPostprin
Specification and analysis of SOC systems using COWS: a finance case study
Service-oriented computing, an emerging paradigm for distributed computing based on the use of services, is calling for the development of tools and techniques to build safe and trustworthy systems, and to analyse their behaviour. Therefore many researchers have proposed to use process calculi, a cornerstone of current foundational research on specification and analysis of concurrent and distributed systems.
We illustrate this approach by focussing on COWS, a process calculus expressly designed for specifying and combining services, while modelling their dynamic behaviour. We present the calculus and one of the analysis techniques it enables, that is based on the temporal logic SocL and the associated model checker CMC. We demonstrate applicability of our tools by means of a large case study, from the financial domain, which is first specified in COWS, and then analysed by using SocL to express many significant properties and CMC to verify them
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