Conference Paper

Evaluating Strategies for Running from the Cops.

Conference: IJCAI 2009, Proceedings of the 21st International Joint Conference on Artificial Intelligence, Pasadena, California, USA, July 11-17, 2009
Source: DBLP

ABSTRACT Moving target search (MTS) or the game of cops and robbers has a broad field of application reach- ing from law enforcement to computer games. Within the recent years research has focused on computing move policies for one or multiple pur- suers (cops). The present work motivates to ex- tend this perspective to both sides, thus developing algorithms for the target (robber). We investigate the game with perfect information for both play- ers and propose two new methods, named TrailMax and Dynamic Abstract Trailmax, to compute move policies for the target. Experiments are conducted by simulating games on 20 maps of the commercial computer game Baldur's Gate and measuring sur- vival time and computational complexity. We test seven algorithms: Cover, Dynamic Abstract Mini- max, minimax, hill climbing with distance heuris- tic, a random beacon algorithm, TrailMax and DA- TrailMax. Analysis shows that our methods outper- form all the other algorithms in quality, achieving up to 98% optimality, while meeting modern com- puter game computation time constraints.

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    ABSTRACT: Vertex pursuit games are widely studied by both graph theorists and computer scientists. Cops and Robbers is a vertex pursuit game played on a graph, where some set of agents (or Cops) attempts to capture a robber. The cop number is the minimum number of cops needed to win. While cop number of a graph has been studied for over 25 years, it is not well understood, and has few connections with existing graph parameters. In this survey, we highlight some of the main results on bounding the cop number, and discuss Meyniel's conjecture on an upper bound for the cop number of connected graphs. We include a new proof of the fact that outerplanar graphs have cop number at most two.


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