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Distributed Context-Aware Systems. An article by Massimo Beneceretti, Paolo Bouquet and Matteo Bonifacio Reviewed by Odd Petter Slyngstad for DT 8107 Distributed Systems, 6/10/2004. Introduction. A few elementary details:
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Distributed Context-Aware Systems An article by Massimo Beneceretti, Paolo Bouquet and Matteo Bonifacio Reviewed by Odd Petter Slyngstad for DT 8107 Distributed Systems, 6/10/2004
Introduction • A few elementary details: • Applications (agents) react according to environment info (context) influencing the application • Allows automatic adaptation to dynamic environments • The notion of context itself has to be dynamic, due to distributed nature (independent dev., distributed control, different goals)
Context • Traditionally thought of as objective, but potential differences makes this unapplicable in distributed context-aware systems: • Contextual features considered • Importance of individual features • Representation/interpretation of features • So, Context is better thought of as subjective!
Context: model & reasoning • Connection between partial and perspective-based environment representations • Local Models Semantics (LMS, Giunchiglia & Ghidini 1998): • A context is a partial and approximate environment representation • Each context is an autonomous environment representation (but they can be related)
Context: Model & Reasoning • Agents do not share context, and consequently • No ”master” list of relevant features exist • Also, Agent semantics (&values sensed) are local (ie. not necessarily related)
Context-aware multi-agent systems • Autonomous computational entities (sensors & effectors) • Physical contexts (example: finding meeting point from different starting points) • Cultural contexts (example: user profile; vegetarian)
Summary Context is a partial & approximate representation of the environment used by an agent to interact with that environment, as well as with other agents. Context as the agent’s viewpoint cannot be shared with other agents. The authors have consequently proposed a shift to a new subjective notion of context, as opposed to the traditional objective notion.