论文标题

在线矢量箱包装的渐近下限

An Asymptotic Lower Bound for Online Vector Bin Packing

论文作者

Bansal, Nikhil, Cohen, Ilan Reuven

论文摘要

我们考虑在线矢量箱包装问题,其中$ d $二维向量指定的$ n $项目必须以最少的相同$ d $维垃圾箱的数量包装。 Azar等。 (Stoc'13)表明,对于任何在线算法$ a $,存在I实例i,因此$ a(i)$,$ a $ a $ to to pack $ i $的垃圾箱数为$ω(d/\ log^2 d)$ times $ times $ opt(i)$,最小的箱子to pack to pack to pack $ i $ i $。但是,在这些情况下,$ opt(i)$仅为$ o(\ log d)$,当$ opt(i)\ gg d $ $渐近竞争比率上,它打开了改进算法的可能性。我们通过证明任何任意函数$ q(\ cdot)$和任何随机在线算法$ a $ a $来排除这一点,存在实例$ i $,以便$ e [a(i)] \ geq c \ geq c \ cdot d/\ log^3d \ cdot opt(i) + q(i) + q(i) + q(i) + q(d)$,对于某些通用常数$ c $。

We consider the online vector bin packing problem where $n$ items specified by $d$-dimensional vectors must be packed in the fewest number of identical $d$-dimensional bins. Azar et al. (STOC'13) showed that for any online algorithm $A$, there exist instances I, such that $A(I)$, the number of bins used by $A$ to pack $I$, is $Ω(d/\log^2 d)$ times $OPT(I)$, the minimal number of bins to pack $I$. However in those instances, $OPT(I)$ was only $O(\log d)$, which left open the possibility of improved algorithms with better asymptotic competitive ratio when $OPT(I) \gg d$. We rule this out by showing that for any arbitrary function $q(\cdot)$ and any randomized online algorithm $A$, there exist instances $I$ such that $ E[A(I)] \geq c\cdot d/\log^3d \cdot OPT(I) + q(d)$, for some universal constant $c$.

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