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arXiv 2406.14535stat.MEmath.STstat.TH
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通过聚类进行多元极值的估计与阶选择

On estimation and order selection for multivariate extremes via clustering

Shiyuan Deng, He Tang, Shuyang Bai

AI总结:

本文提出带惩罚的简化平均轮廓宽度来一致选择多元极值谱测度的聚类阶,并分析聚类估计的大偏差性质及重尾因子模型参数估计。

摘要:

我们研究使用球面聚类技术估计具有离散谱测度的多元极值模型。主要贡献在于设计了一种选择阶(即聚类数量)的方法。该方法能够一致地识别真实阶,即谱原子的数量,并且在实践中具有直观的实现方式。具体而言,我们在著名的简化平均轮廓宽度中引入了一个额外惩罚项,该项对较小的聚类规模以及聚类中心之间较小的不相似性进行惩罚。因此,我们提供了一种确定最大线性因子模型阶数的一致方法,而在该模型中,典型的基于信息的方法并不可行。我们的第二项贡献是对通过聚类方法估计离散谱测度进行大偏差类型分析,该分析用于评估基于聚类的多元极值估计的收敛质量。此外,作为第三项贡献,我们讨论了估计离散测度如何能够带来重尾因子模型的参数估计。我们还给出了模拟和真实数据研究,以展示阶选择和因子模型估计。

英文摘要:

We investigate the estimation of multivariate extreme models with a discrete spectral measure using spherical clustering techniques. The primary contribution involves devising a method for selecting the order, that is, the number of clusters. The method consistently identifies the true order, i.e., the number of spectral atoms, and enjoys intuitive implementation in practice. Specifically, we introduce an extra penalty term to the well-known simplified average silhouette width, which penalizes small cluster sizes and small dissimilarities between cluster centers. Consequently, we provide a consistent method for determining the order of a max-linear factor model, where a typical information-based approach is not viable. Our second contribution is a large-deviation-type analysis for estimating the discrete spectral measure through clustering methods, which serves as an assessment of the convergence quality of clustering-based estimation for multivariate extremes. Additionally, as a third contribution, we discuss how estimating the discrete measure can lead to parameter estimations of heavy-tailed factor models. We also present simulations and real-data studies that demonstrate order selection and factor model estimation.

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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