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Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering)  2005, Vol. 6 Issue ( 6): 19-    DOI: 10.1631/jzus.2005.A0591
    
Semi on-line scheduling for maximizing the minimum machine completion time on three uniform machines
LUO Run-zi, SUN Shi-jie
Department of Mathematics, Shanghai University, Shanghai 200444, China
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Abstract  The paper investigates a semi on-line scheduling problem wherein the largest processing time of jobs done by three uniform machines M1, M2, M3 is known in advance. A speed si (s1=1, s2=r, s3=s, 1£r£s) is associated with machine Mi. Our goal is to maximize Cmin-the minimum workload of the three machines. We present a min3 algorithm and prove its competitive ratio is max{r+1,(3s+r+1)/(1+r+s)}, with the lower bound being at least max{2,r}. We also claim the competitive ratio of min3 algorithm cannot be improved and is the best possible for 1£s£2, r=1.

Key wordsMathematics Scheduling      Semi on-line      Competitive ratio     
CLC:  O223  
Cite this article:

LUO Run-zi, SUN Shi-jie. Semi on-line scheduling for maximizing the minimum machine completion time on three uniform machines. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6( 6): 19-.

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http://www.zjujournals.com/xueshu/zjus-a/10.1631/jzus.2005.A0591     OR     http://www.zjujournals.com/xueshu/zjus-a/Y2005/V6/I 6/19

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