Optimal non-preemptive semi-online scheduling on two related machines

Leah Epstein, Lene M. Favrholdt

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Weconsider the following non-preemptive semi-online scheduling problem. Jobs with non-increasing sizes arrive one by one to be scheduled on two uniformly related machines, with the goal of minimizing the makespan. We analyze both the optimal overall competitive ratio, and the optimal competitive ratio as a function of the speed ratio (q ≥ 1) between the two machines. We show that the greedy algorithm LPT has optimal competitive ratio ¼ (1 + √17) ≈ 1.28 overall, but does not have optimal competitive ratio for every value of q. Wedetermine the intervals of q where LPT is an algorithm of optimal competitive ratio, and design different algorithms of optimal competitive ratio for the intervals where it fails to be the best algorithm. As a result, we give a tight analysis of the competitive ratio for every speed ratio.

Original languageEnglish
Title of host publicationMathematical Foundations of Computer Science 2002 - 27th International Symposium, MFCS 2002, Proceedings
EditorsKrzysztof Diks, Wojciech Rytter, Wojciech Rytter
PublisherSpringer Verlag
Pages245-256
Number of pages12
ISBN (Print)3540440402, 9783540440406
DOIs
StatePublished - 2002
Externally publishedYes
Event27th International Symposium on Mathematical Foundations of Computer Science, MFCS 2002 - Warsaw, Poland
Duration: 26 Aug 200230 Aug 2002

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume2420
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference27th International Symposium on Mathematical Foundations of Computer Science, MFCS 2002
Country/TerritoryPoland
CityWarsaw
Period26/08/0230/08/02

Bibliographical note

Funding Information:
– The research of Lene M. Favrholdt was supported in part by the Danish Natural Sci-ence Research Council (SNF) and in part by the Future and Emerging Technologies program of the EU under contract number IST-1999-14186 (ALCOM-FT).

Funding Information:
– The research of Leah Epstein was supported in part by the Israel Science Foundation, (grant no. 250/01).

Publisher Copyright:
© Springer-Verlag Berlin Heidelberg 2002.

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science (all)

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