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arXiv 1601.03095cs.DScs.AIcs.GT
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噪声下的子模块优化

Submodular Optimization under Noise

Bar Ilan University(巴伊兰大学);Harvard University(哈佛大学)

Avinatan Hassidim, Yaron Singer

摘要:

本文研究噪声下单调次模函数的极大化问题。在各种约束条件下的子模函数的优化方面已经有了大量的工作,从而产生了提供理想的近似保证的算法。然而,在许多应用中,我们无法访问我们要优化的子模函数,而是访问它的一些错误或噪声版本。这就提出了一个问题,即在存在错误和噪声的情况下,是否可以获得可证明的保证。我们提供了初步的答案,通过集中在基数约束下的单调子模函数最大化的问题时,获得一个嘈杂的预言的功能。我们证明:- 对于基数约束$k \geq 2$,存在其近似比任意接近于$1-1/e$的近似算法; -对于$k=1$,存在其近似比任意接近于$1/2$的算法。没有随机算法可以获得比$1/2+o(1)$更好的近似比; -如果噪声是对抗性的,则不能获得非平凡近似保证。

英文摘要:

We consider the problem of maximizing a monotone submodular function under noise. There has been a great deal of work on optimization of submodular functions under various constraints, resulting in algorithms that provide desirable approximation guarantees. In many applications, however, we do not have access to the submodular function we aim to optimize, but rather to some erroneous or noisy version of it. This raises the question of whether provable guarantees are obtainable in presence of error and noise. We provide initial answers, by focusing on the question of maximizing a monotone submodular function under a cardinality constraint when given access to a noisy oracle of the function. We show that: - For a cardinality constraint $k \geq 2$, there is an approximation algorithm whose approximation ratio is arbitrarily close to $1-1/e$; - For $k=1$ there is an algorithm whose approximation ratio is arbitrarily close to $1/2$. No randomized algorithm can obtain an approximation ratio better than $1/2+o(1)$; -If the noise is adversarial, no non-trivial approximation guarantee can be obtained.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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