Amortized efficiency of list update and paging rules
Communications of the ACM
The Accommodating Function: A Generalization of the Competitive Ratio
SIAM Journal on Computing
The competitive ratio for on-line dual bin packing with restricted input sequences
Nordic Journal of Computing
Tight bounds on the competitive ratio on accommodating sequences for the seat reservation problem
Journal of Scheduling - Special issue: On-line algorithm part I
SIGACT news online algorithms column 8
ACM SIGACT News
An online algorithm optimally self-tuning to congestion for power management problems
WAOA'11 Proceedings of the 9th international conference on Approximation and Online Algorithms
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We consider a variant of the Seat Reservation Problem [J. Boyar, K.S. Larsen, Algorithmica 25 (1999) 403-417] in which seat changes are allowed. We analyze the model using the competitive ratio, the competitive ratio on accommodating sequences [J. Boyar, K.S. Larsen, Algorithmica 25 (1999) 403-417], and the accommodating function [J. Boyar et al., Acta Informatica 40 (2003) 3-35, J. Boyar et al., SIAM J. Comput. 31 (1) (2001) 233-258]. A very promising family of algorithms considered in this paper is Min-Change, which will ask passengers to change seats, only if they would otherwise have been rejected. Min-Change belongs to a large class of conservative algorithms, which all have very high performance guarantees. For instance, if the optimal off-line algorithm can seat all of the passengers, 2/3 of the passengers can be seated on-line using any conservative algorithm allowing only one seat change and 3/4 will be seated if two seat changes are allowed. This should be compared to the asymptotic hardness result of 1/2 for the best algorithm when no seat changes are allowed [E. Bach et al., J. Sched. 6 (2003) 131-147]. Another interesting algorithm, Modified-Kierstead-Trotter, is proposed and shown to seat all passengers if the optimal off-line algorithm could have accommodated them with only half as many seats. On this type of sequence, Modified-Kierstead-Trotter is strictly better than Min-Change-First-Fit which is strictly better than the Checkerboard algorithm.