Search Results - "Lidbetter, Thomas"

On the approximation ratio of the Random Chinese Postman Tour for network search by Lidbetter, Thomas

“…•We study the Random Chinese Postman Tour strategy for network search games.•For Gal’s classic game, the strategy is a 4/3-approximation for the optimal…”
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Mining Coal or Finding Terrorists: The Expanding Search Paradigm by Alpern, Steve, Lidbetter, Thomas

“…We show how to optimize the search for a hidden object, terrorist, or simply Hider, located at a point H according to a known or unknown distribution ν on a…”
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Optimizing periodic patrols against short attacks on the line and other networks by Alpern, Steve, Lidbetter, Thomas, Papadaki, Katerina

“…•Periodic patrolling games: Patroller versus attacker.•Attack duration two time periods.•For time horizon even, game is solved for arbitrary graphs.•Complete…”
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Patrolling a Border by Papadaki, Katerina, Alpern, Steve, Lidbetter, Thomas, Morton, Alec

“…Patrolling games were recently introduced to model the problem of protecting the nodes of a network from an attack. Time is discrete and in each time unit the…”
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Searching a Variable Speed Network by Alpern, Steve, Lidbetter, Thomas

“…A point lies on a network according to some unknown probability distribution. Starting at a specified root of the network, a Searcher moves to find this point…”
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Optimal Trade-Off Between Speed and Acuity When Searching for a Small Object by Alpern, Steve, Lidbetter, Thomas

“…A Searcher seeks to find a stationary Hider located at some point H (not necessarily a node) on a given network Q . The Searcher can move along the network…”
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The solution to an open problem for a caching game by Csóka, Endre, Lidbetter, Thomas

“…In a caching game introduced by Alpern et al. (Alpern et al., Lecture notes in computer science (2010) 220–233) a Hider who can dig to a total fixed depth…”
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Search and rescue in the face of uncertain threats by Lidbetter, Thomas

“…•We consider a search and rescue scenario where multiple targets must be rescued.•There is a threat that the Searcher will be captured or otherwise…”
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A search game model of the scatter hoarder's problem by Alpern, Steve, Fokkink, Robbert, Lidbetter, Thomas, Clayton, Nicola S.

“…Scatter hoarders are animals (e.g. squirrels) who cache food (nuts) over a number of sites for later collection. A certain minimum amount of food must be…”
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A game theoretic approach to a problem in polymatroid maximization by Hellerstein, Lisa, Lidbetter, Thomas

“…•A classic problem in polymatroid optimization can be formulated as a zero-sum game.•Optimal strategies in this game and three variations can be derived…”
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Competitive search in a network by Angelopoulos, Spyros, Lidbetter, Thomas

“…•Search games in a network: pathwise and expanding search.•Exact vs. approximate competitive analysis.•Optimal deterministic expanding search.•Randomized…”
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The search and rescue game on a cycle by Lidbetter, Thomas, Xie, Yifan

“…We consider a search and rescue game introduced recently by the first author. An immobile target or targets (for example, injured hikers) are hidden on a…”
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Improved bound for the Gerver-Ramsey collinearity problem by Lidbetter, Thomas F.

“…Let S be a finite subset of Zn. A vector sequence (zi) is an S-walk if and only if zi+1−zi is an element of S for all i. Gerver and Ramsey showed in 1979 that…”
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Search and Delivery Man Problems: When are depth-first paths optimal? by Alpern, Steve, Lidbetter, Thomas

“…•A target is hidden on a tree network according to a known probability distribution.•When is the trajectory that finds the target in minimum expected time…”
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Approximate solutions for expanding search games on general networks by Alpern, Steve, Lidbetter, Thomas

“…We study the classical problem introduced by R. Isaacs and S. Gal of minimizing the time to find a hidden point H on a network Q moving from a known starting…”
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Optimal patrolling strategies for trees and complete networks by Bui, Thuy, Lidbetter, Thomas

“…•We consider a continuous patrolling game played on trees and complete networks.•The game is modeled as a zero-sum game between an Attacker and a Patroller.•We…”
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The Largest-Z-ratio-First algorithm is 0.8531-approximate for scheduling unreliable jobs on m parallel machines by Agnetis, Alessandro, Lidbetter, Thomas

“…In this paper we analyze the worst-case performance of a greedy algorithm called Largest-Z-ratio-First for the problem of scheduling unreliable jobs on m…”
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Optimal pure strategies for a discrete search game by Bui, Thuy, Lidbetter, Thomas, Lin, Kyle Y.

“…•We consider a discrete search game between a Hider and a Searcher.•The game is modeled as a semi-finite two-person zero-sum game.•We show that the Searcher…”
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Searching for multiple objects in multiple locations by Lidbetter, Thomas, Lin, Kyle Y.

“…•We model problems where several targets such as earthquake survivors must be found.•To do so we introduce new classes of search games with multiple objects…”
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Computational aspects of sturdy and flimsy numbers by Clokie, Trevor, Lidbetter, Thomas F., Molina Lovett, Antonio, Shallit, Jeffrey, Witzman, Leon

“…Following Stolarsky, we say that a natural number n is flimsy in base b if some positive multiple of n has smaller digit sum in base b than n does; otherwise…”
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