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Title: Policy-based asset sharing in collaborative environments
Author: Parizas, Christos
ISNI:       0000 0004 5915 1495
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2015
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Resource sharing is an important but complex problem to be solved. The problem is exacerbated in a dynamic coalition context, due to multi-partner constraints (imposed by security, privacy and general operational issues) placed on the resources. Take for example scenarios such as emergency response operations, corporate collaborative environments, or even short-lived opportunistic networks, where multi-party teams are formed, utilizing and sharing their own resources in order to support collective endeavors, which otherwise would be difficult, if not impossible, to achieve by a single party. Policy-Based Management Systems (PBMS) have been proposed as a suitable paradigm to reduce this complexity and provide a means for effective resource sharing. The overarching problem that this thesis deals with, is the development of PBMS techniques and technologies that will allow in a dynamic and transparent way, users that operate in collaborative environments to share their assets through high-level policies. To do so, it focuses on three sub-problems each one of which is related to a different aspect of a PBMS, making three key contributions. The first is a novel model, which proposes an alternative way for asset sharing, better fit than the traditional approaches when dealing with collaborative and dynamic environments. In order for all of the existing asset sharing approaches to comply with situational changes, an extra overhead is needed due to the fact that the decision making centre – and therefore, the policy making centre – is far away from where the changes take place unlike the event-driven approach proposed in this thesis. The second contribution is the proposal of an efficient, high-level policy conflict analysis mechanism, that provides a more transparent – in terms of user interaction – alternative way for maintaining unconflicted PBMS. Its discrete and sequential execution, breaks down the analysis process into discrete steps, making the conflict analysis more efficient compared to existing approaches, while eases human policy authors to track the whole process interfacing with it, in a near to natural language representation. The contribution of the third piece of research work is an interest-based policy negotiation mechanism, for enhancing asset sharing while promoting collaboration in coalition environments. The enabling technology for achieving the last two contributions (contribution 2 & 3) is a controlled natural language representation, which is used for defining a policy language. For evaluating the proposed ideas, in the first and third contributions we run simulation experiments while we simulate and also conduct formal analysis for the second one.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QA75 Electronic computers. Computer science