论文标题

改进了K均和K-Medians聚集的学习算法的学习算法

Improved Learning-augmented Algorithms for k-means and k-medians Clustering

论文作者

Nguyen, Thy, Chaturvedi, Anamay, Nguyen, Huy Lê

论文摘要

我们考虑在学习淘汰的设置中聚类的问题,在该设置中,我们将在$ d $维欧几里得空间中为数据集,以及由Oracle给出的每个数据点的标签,指示应将哪些点集聚合在一起。此设置捕获了我们可以访问有关与我们的聚类目标相关的数据集的一些辅助信息,例如神经网络输出的标签。在事先工作之后,我们假设最多有$α\ in(0,c)$,对于$ c <1 $ $ c <1 $的误报和假否定量的一小部分,而在每个预测的群集中,在没有标签的情况下,标签将达到最佳群集成本$ \ m mathrm {optrm {opt} $。 对于大小$ m $的数据集,我们提出了一种确定性的$ k $ -MEANS算法,该算法与以前的随机算法相比,在群集成本上产生了改进的中心,同时保留$ O(D M \ log M)$ RUNTIME。此外,即使预测不太准确,我们的算法也起作用,即,我们的限制的价格最高为$ 1/2美元,超过$α$的改善最多是上一项工作中$ 1/7 $。对于$ k $ -Medians的问题,我们通过实现近似因素对准确性参数$α$的依赖性的依赖性来改善先前工作的问题,以获得$(1+O(α))\ Mathrm {opt} $的成本,而本质上只需要$ O(MD \ log^3 m/α)。

We consider the problem of clustering in the learning-augmented setting, where we are given a data set in $d$-dimensional Euclidean space, and a label for each data point given by an oracle indicating what subsets of points should be clustered together. This setting captures situations where we have access to some auxiliary information about the data set relevant for our clustering objective, for instance the labels output by a neural network. Following prior work, we assume that there are at most an $α\in (0,c)$ for some $c<1$ fraction of false positives and false negatives in each predicted cluster, in the absence of which the labels would attain the optimal clustering cost $\mathrm{OPT}$. For a dataset of size $m$, we propose a deterministic $k$-means algorithm that produces centers with improved bound on clustering cost compared to the previous randomized algorithm while preserving the $O( d m \log m)$ runtime. Furthermore, our algorithm works even when the predictions are not very accurate, i.e. our bound holds for $α$ up to $1/2$, an improvement over $α$ being at most $1/7$ in the previous work. For the $k$-medians problem we improve upon prior work by achieving a biquadratic improvement in the dependence of the approximation factor on the accuracy parameter $α$ to get a cost of $(1+O(α))\mathrm{OPT}$, while requiring essentially just $O(md \log^3 m/α)$ runtime.

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