Uniform service systems with k servers
We consider the problem of k servers situated on a uniform metric space that must serve a sequence of requests, where each request consists of a set of locations of the metric space and can be served by moving a server to any of the nodes of the set. The goal is to minimize the total distance traveled by the servers. This problem generalizes a problem presented by Chrobak and Larmore in . We give lower and upper bounds on the competitive ratio achievable by on-line algorithms for this problem, and consider also interesting particular cases.
KeywordsCompetitive Ratio Online Algorithm Vertex Cover Total Completion Time Competitive Algorithm
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- 1.H. Alborzi, E. Torng, P. Uthaisombut, and S. Wagner. The k-client problem. In Proc. of Eigth Annual ACM-SIAM Symposium on Discrete Algorithms (SODA), 1995.Google Scholar
- 2.G. Ausiello, E. Feuerstein, S. Leonardi, L. Stougie, and M. Talamo. Competitive algorithms for the traveling salesman. In Proc. of Workshop on Algorithms and Data Structures (WADS'95), Springer-Verlag, 1995.Google Scholar
- 3.G. Ausiello, E. Feuerstein, S. Leonardi, L. Stougie, and M. Talamo. Serving requests with on-line routing. In Proc. of 4th Scandinavian Workshop on Algorithm Theory (SWAT'94), pages 37–48, Springer-Verlag, July 1995.Google Scholar
- 5.A. Borodin, Sandy Irani, P. Raghavan, and B. Schieber. Competitive paging with locality of reference. In Proc. of 23rd ACM Symposium on Theory of Computing, pages 249–259, 1991.Google Scholar
- 7.M. Chrobak and L. Larmore. The server problem and on-line games. In On-line Algorithms, pages 11–64, AMS-ACM, 1992.Google Scholar
- 8.E. Feuerstein. Paging more than one page. In Proceedings of the Second Latin American Symposium on Theoretical Informatics (LATIN95), pages 272–287, Springer-Verlag, 1995. An improved version of this paper will appeax in Theoretical Computer Science (1997).Google Scholar
- 9.E. Feuerstein and A. Strejilevich de Loma. On multi-threaded paging. In Proceedings of the 7th International Symposium on Algorithms and Computation (ISAAC'96), Springer-Verlag, 1996.Google Scholar
- 10.M. R. Garey and D. S. Johnson. Computers and Intractabiliy — A Guide to the Theory of NP-completeness. W.H. Freeman and Company, San Francisco, 1979.Google Scholar
- 13.R. Motwani. Lecture Notes on Approximation Algorithms. Technical Report, Stanford University.Google Scholar
- 14.P. Raghavan and M. Snir. Memory versus randomization in on-line algorithms. RC 15622, IBM, 1990.Google Scholar