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Exploiting Vagueness for Multi-agent Consensus

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Multi-agent and Complex Systems

Part of the book series: Studies in Computational Intelligence ((SCI,volume 670))

Abstract

A framework for consensus modelling is introduced using Kleene’s three valued logic as a means to express vagueness in agents’ beliefs. Explicitly borderline cases are inherent to propositions involving vague concepts where sentences of a propositional language may be absolutely true, absolutely false or borderline. By exploiting these intermediate truth values, we can allow agents to adopt a more vague interpretation of underlying concepts in order to weaken their beliefs and reduce the levels of inconsistency, so as to achieve consensus. We consider a consensus combination operation which results in agents adopting the borderline truth value as a shared viewpoint if they are in direct conflict. Simulation experiments are presented which show that applying this operator to agents chosen at random (subject to a consistency threshold) from a population, with initially diverse opinions, results in convergence to a smaller set of more precise shared beliefs. Furthermore, if the choice of agents for combination is dependent on the payoff of their beliefs, this acting as a proxy for performance or usefulness, then the system converges to beliefs which, on average, have higher payoff.

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Notes

  1. 1.

    In preliminary experiments we found that 50, 000 was an upper bound on the number of iterations required for the system to reach steady state across a range of parameter settings.

  2. 2.

    As a result of this Boolean initialisation, a language size of 5 now produces a total of \(2^5\) (32) possible valuations, as opposed to \(3^5\) (243) possible valuations.

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Acknowledgments

This research is partially funded by an EPSRC PhD studentship as part of a doctoral training partnership (DTP).

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Correspondence to Michael Crosscombe .

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Crosscombe, M., Lawry, J. (2017). Exploiting Vagueness for Multi-agent Consensus. In: Bai, Q., Ren, F., Fujita, K., Zhang, M., Ito, T. (eds) Multi-agent and Complex Systems. Studies in Computational Intelligence, vol 670. Springer, Singapore. https://doi.org/10.1007/978-981-10-2564-8_5

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  • DOI: https://doi.org/10.1007/978-981-10-2564-8_5

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