Amortized efficiency of list update and paging rules
Communications of the ACM
Amortized analyses of self-organizing sequential search heuristics
Communications of the ACM - Lecture notes in computer science Vol. 174
A case for redundant arrays of inexpensive disks (RAID)
SIGMOD '88 Proceedings of the 1988 ACM SIGMOD international conference on Management of data
No. 318 on SWAT 88: 1st Scandinavian workshop on algorithm theory
Competitive algorithms for server problems
Journal of Algorithms
An optimal on-line algorithm for K-servers on trees
SIAM Journal on Computing
The harmonic online K-server algorithm is competitive
STOC '91 Proceedings of the twenty-third annual ACM symposium on Theory of computing
New results on server problems
SIAM Journal on Discrete Mathematics
Theoretical Computer Science
An optimal on-line algorithm for metrical task system
Journal of the ACM (JACM)
Competitive k-server algorithms
Journal of Computer and System Sciences - Special issue: 31st IEEE conference on foundations of computer science, Oct. 22–24, 1990
Competitive algorithms for the weighted server problem
Theoretical Computer Science - Special issue on dynamic and on-line algorithms
STOC '94 Proceedings of the twenty-sixth annual ACM symposium on Theory of computing
Online computation and competitive analysis
Online computation and competitive analysis
SIAM Journal on Computing
The harmonic k-server algorithm is competitive
Journal of the ACM (JACM)
VLDB '88 Proceedings of the 14th International Conference on Very Large Data Bases
A competitive algorithm for the general 2-server problem
ICALP'03 Proceedings of the 30th international conference on Automata, languages and programming
The generalized two-server problem
Journal of the ACM (JACM)
A lower bound on the competitivity of memoryless algorithms for a generalization of the CNN problem
Theoretical Computer Science
Online chasing problems for regular polygons
Information Processing Letters
Hi-index | 0.00 |
We study several interesting variants of the k-server problem. In the CNN problem, one server services requests in the Euclidean plane. The difference from the k-server problem is that the server does not have to move to a request, but it has only to move to a point that lies in the same horizontal or vertical line with the request. This, for example, models the problem faced by a crew of a certain News Network trying to shoot scenes on the streets of Manhattan from a distance; for any event at an intersection, the crew has only to be on a matching street or avenue. The CNN problem contains as special cases two important problems: the BRIDGE problem, also known as the cow-path problem, and the weighted 2-server problem in which the 2 servers may have different speeds. We show that any deterministic online algorithm has competitive ratio at least 6 + √17. We also show that some successful algorithms for the k-server problem fail to be competitive. In particular, no memoryless randomized algorithm can be competitive.We also consider another variant of the k-server problem, in which servers can move simultaneously, and we wish to minimize the time spent waiting for service. This is equivalent to the regular k-server problem under the L∞ norm for movement costs. We give a ½ k(k + 1) upper bound for the competitive ratio on trees.