Title
Local Similarity Search on Geolocated Time Series Using Hybrid Indexing.
Abstract
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.
Year
DOI
Venue
2019
10.1145/3347146.3359349
SIGSPATIAL/GIS
Keywords
Field
DocType
local similarity, geolocated time series, hybrid indexing
Data mining,Computer science,Search engine indexing,Nearest neighbor search
Conference
ISBN
Citations 
PageRank 
978-1-4503-6909-1
1
0.35
References 
Authors
0
6
Name
Order
Citations
PageRank
Georgios Chatzigeorgakidis133.41
Dimitrios Skoutas283355.09
Kostas Patroumpas332730.03
Themis Palpanas4113691.61
Spiros Athanasiou521.03
Spiros Skiadopoulos6113965.60