[show abstract][hide abstract] ABSTRACT: In this paper we propose a use-case-driven iterative design methodology for
normative frameworks, also called virtual institutions, which are used to
govern open systems. Our computational model represents the normative framework
as a logic program under answer set semantics (ASP). By means of an inductive
logic programming approach, implemented using ASP, it is possible to synthesise
new rules and revise the existing ones. The learning mechanism is guided by the
designer who describes the desired properties of the framework through use
cases, comprising (i) event traces that capture possible scenarios, and (ii) a
state that describes the desired outcome. The learning process then proposes
additional rules, or changes to current rules, to satisfy the constraints
expressed in the use cases. Thus, the contribution of this paper is a process
for the elaboration and revision of a normative framework by means of a
semi-automatic and iterative process driven from specifications of
(un)desirable behaviour. The process integrates a novel and general methodology
for theory revision based on ASP.
Theory and Practice of Logic Programming 07/2011; 11. · 0.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: Recent years have seen a significant increase in the popularity of social networking services. These online services enable users to construct groups of contacts, referred to as friends, with which they can share digital content and communicate. This sharing is actively encouraged by the social networking services, with users' privacy often seen as a secondary concern. In this paper we first propose a privacy-aware social networking service and then introduce a collaborative approach to authoring privacy policies for the service. In addressing user privacy, our approach takes into account the needs of all parties affected by the disclosure of information and digital content.
Policies for Distributed Systems and Networks (POLICY), 2010 IEEE International Symposium on; 08/2010
[show abstract][hide abstract] ABSTRACT: The online presence projected by a person is comprised of all the information about them available on the Internet. In online communities and social networking services, it is often possible for third-parties to modify this content by, for example, commenting on existing content or uploading new content. This has the potential to negatively impact the privacy of a presence owner (the person referred to by the on-line content) by disclosing information about them without consent. In this paper we propose a Privacy Butler, an automated service that can monitor a person's online presence and attempt to make corrections based on policies specified by the owner of the online presence.
Pervasive Computing and Communications Workshops (PERCOM Workshops), 2010 8th IEEE International Conference on; 05/2010
[show abstract][hide abstract] ABSTRACT: In the physical world, the rules governing behaviour are debugged by observing an outcome that was not intended and the addition
of new constraints to prevent the attainment of that outcome. We propose a similar approach to support the incremental development
of normative frameworks (also called institutions) and demonstrate how this works through the validation and synthesis of
normative rules using model generation and inductive learning. This is achieved by the designer providing a set of use cases, comprising collections of event traces that describe how the system is used along with the desired outcome with respect
to the normative framework. The model generator encodes the description of the current behaviour of the system. The current
specification and the traces for which current behaviour and expected behaviour do not match are given to the learning framework
to propose new rules that revise the existing norm set in order to inhibit the unwanted behaviour. The elaboration of a normative
system can then be viewed as a semi-automatic, iterative process for the detection of incompleteness or incorrectness of the
existing normative rules, with respect to desired properties, and the construction of potential additional rules for the normative
Coordination, Organizations, Institutions, and Norms in Agent Systems VI - COIN 2010 International Workshops, COIN@AAMAS 2010, Toronto, Canada, May 2010, COIN@MALLOW 2010, Lyon, France, August 2010, Revised Selected Papers; 01/2010
[show abstract][hide abstract] ABSTRACT: Pervasive computing requires infrastructures that adapt to changes in user behaviour while minimising user interactions. Policy-basedapproaches have been proposed as a means of providing adaptability but, at present, require policy goals and rules to be explicitly defined by users. This paper presents a novel, logic-based approach for automatically learning and updating models of users from their observed behaviour. We show how this task can be accomplished using a nonmonotonic learning system, and we illustrate how the approach can be exploited within a pervasive computing framework.