Online Scheduling of Equal-Length Jobs: Randomization and Restarts Help

  • Marek Chrobak
  • Wojciech Jawor
  • Jiří Sgall
  • Tomáš Tichý
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3142)


The input of the studied scheduling problem is a set of jobs with equal processing times, where each job is specified by its release time and deadline. The goal is to determine a single-processor, non-preemptive schedule that maximizes the number of completed jobs. In the online version, each job arrives at its release time.

First, we give a barely random \(\frac{5}{3}\)-competitive algorithm that uses only one random bit; we also show a lower bound of \(\frac{3}{2}\) for barely random algorithms that choose one of two deterministic algorithms. Second, we give a deterministic \(\frac{3}{2}\)-competitive algorithm in the model that allows restarts, and we show that in this model the ratio \(\frac{3}{2}\) is optimal.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2004

Authors and Affiliations

  • Marek Chrobak
    • 1
  • Wojciech Jawor
    • 1
  • Jiří Sgall
    • 2
  • Tomáš Tichý
    • 2
  1. 1.Department of Computer ScienceUniversity of CaliforniaRiversideUSA
  2. 2.Mathematical InstituteAS CRPraha 1Czech Republic

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