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arXiv 2104.09509cs.DB
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基于混合索引的地理时间序列局部相似性搜索

Local Similarity Search on Geolocated Time Series Using Hybrid Indexing

Georgios Chatzigeorgakidis, Dimitrios Skoutas, Kostas Patroumpas, Themis Palpanas, Spiros Athanasiou, Spiros Skiadopoulos

摘要:

地理位置的时间序列,即,与特定位置相关的时间序列,在许多现代应用中比比皆是。在本文中,我们考虑混合查询检索地理定位的时间序列过滤器的基础上,结合空间距离和时间序列的相似性。对于后者,与现有的工作不同,我们允许基于局部相似性进行过滤,这是基于连续性而不是每个系列的整个长度计算的,从而允许发现更细粒度的趋势和模式。为了有效地支持这样的查询,我们首先利用国家的最先进的BTSR树索引,利用时间序列的位置和形状的界限修剪的搜索空间。此外,我们提出了优化,检查在特定的时间戳,以确定可能超过所需的本地相似性阈值的候选时间序列。为了进一步提高剪枝能力,我们引入了SBTSR树索引,这是对BTSR树的扩展,它在时间上对时间序列进行了额外的分段,从而可以构建更严格的边界。我们在几个真实数据集上的实验结果表明,SBTSR树可以为所有检查的查询类型提供更快的答案。该论文发表在第27届地理信息系统进展国际会议(ACM SIGSPATIAL 2019)上。

英文摘要:

Geolocated time series, i.e., time series associated with certain locations, abound in many modern applications. In this paper, we consider hybrid queries for retrieving geolocated time series based on filters that combine spatial distance and time series similarity. For the latter, unlike existing work, we allow filtering based on local similarity, which is computed based on subsequences rather than the entire length of each series, thus allowing the discovery of more fine-grained trends and patterns. To efficiently support such queries, we first leverage the state-of-the-art BTSR-tree index, which utilizes bounds over both the locations and the shapes of time series to prune the search space. Moreover, we propose optimizations that check at specific timestamps to identify candidate time series that may exceed the required local similarity threshold. To further increase pruning power, we introduce the SBTSR-tree index, an extension to BTSR-tree, which additionally segments the time series temporally, allowing the construction of tighter bounds. Our experimental results on several real-world datasets demonstrate that SBTSR-tree can provide answers much faster for all examined query types. This paper has been published in the 27th International Conference on Advances in Geographic Information Systems (ACM SIGSPATIAL 2019).

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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