论文标题

双变量卫星时间序列的聚类:一种分位数方法

Clustering of bivariate satellite time series: a quantile approach

论文作者

Musau, Victor Muthama, Gaetan, Carlo, Girardi, Paolo

论文摘要

聚类在统计和机器学习中引起了很多关注,其目的是开发能够从原始数据中获取信息以进行探索性分析的统计模型和自主算法。已经开发了几个几个技术来样本进行抽样的单变量矢量,仅在整个期间中仅考虑到整个过程中的平均值,并且在整个过程中都无法探索整体的特征。我们提出了一种基于模型的聚类技术,该技术基于分位数回归,允许我们在不同的分位水平上进行双变量时间序列。我们使用不对称拉式分布对内集群密度进行建模,从而使我们可以考虑数据分布中的不对称性。我们通过模拟研究评估了提出的技术的性能。然后将该方法应用于与营养状态指数相关的球形卫星数据观察到的群集时间序列,目的是评估其时间动力学,以便在gabes海湾中鉴定出均匀的区域。

Clustering has received much attention in Statistics and Machine learning with the aim of developing statistical models and autonomous algorithms which are capable of acquiring information from raw data in order to perform exploratory analysis.Several techniques have been developed to cluster sampled univariate vectors only considering the average value over the whole period and as such they have not been able to explore fully the underlying distribution as well as other features of the data, especially in presence of structured time series. We propose a model-based clustering technique that is based on quantile regression permitting us to cluster bivariate time series at different quantile levels. We model the within cluster density using asymmetric Laplace distribution allowing us to take into account asymmetry in the distribution of the data. We evaluate the performance of the proposed technique through a simulation study. The method is then applied to cluster time series observed from Glob-colour satellite data related to trophic status indices with aim of evaluating their temporal dynamics in order to identify homogeneous areas, in terms of trophic status, in the Gulf of Gabes.

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