Journal of Zhejiang University-SCIENCE A

, Volume 8, Issue 1, pp 127–133 | Cite as

Online algorithms for scheduling with machine activation cost on two uniform machines



In this paper we investigate a variant of the scheduling problem on two uniform machines with speeds 1 and s. For this problem, we are given two potential uniform machines to process a sequence of independent jobs. Machines need to be activated before starting to process, and each machine activated incurs a fixed machine activation cost. No machines are initially activated, and when a job is revealed, the algorithm has the option to activate new machines. The objective is to minimize the sum of the makespan and the machine activation cost. We design optimal online algorithms with competitive ratio of (2s+1)/(s+1) for every s≥1.

Key words

Online algorithm Competitive analysis Uniform machine scheduling Machine activation cost 

CLC number

TP393 O223 


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Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Han Shu-guang 
    • 1
  • Jiang Yi-wei 
    • 2
  • Hu Jue-liang 
    • 2
  1. 1.Department of MathematicsZhejiang UniversityHangzhouChina
  2. 2.Faculty of ScienceZhejiang Sci-Tech UniversityHangzhouChina

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