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Journal of Combinatorial Optimization

, Volume 12, Issue 4, pp 363–386 | Cite as

Separating online scheduling algorithms with the relative worst order ratio

  • Leah Epstein
  • Lene M. Favrholdt
  • Jens S. Kohrt
Article

Abstract

The relative worst order ratio is a measure for the quality of online algorithms. Unlike the competitive ratio, it compares algorithms directly without involving an optimal offline algorithm. The measure has been successfully applied to problems like paging and bin packing. In this paper, we apply it to machine scheduling. We show that for preemptive scheduling, the measure separates multiple pairs of algorithms which have the same competitive ratios; with the relative worst order ratio, the algorithm which is “intuitively better” is also provably better. Moreover, we show one such example for non-preemptive scheduling.

Keywords

Online algorithms Relative worst order ratio Scheduling 

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Copyright information

© Springer Science + Business Media, LLC 2006

Authors and Affiliations

  • Leah Epstein
    • 1
  • Lene M. Favrholdt
    • 2
  • Jens S. Kohrt
    • 2
  1. 1.Department of MathematicsUniversity of HaifaHaifaIsrael
  2. 2.Department of Mathematics and Computer ScienceUniversity of Southern DenmarkOdenseDenmark

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