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Issue No. 04 - April (2017 vol. 29)
ISSN: 1041-4347
pp: 870-883
Na Ta , Department of Computing Science, TNList, Tsinghua University, Beijing, China
Guoliang Li , Department of Computing Science, TNList, Tsinghua University, Beijing, China
Yongqing Xie , Department of Computing Science, TNList, Tsinghua University, Beijing, China
Changqi Li , Renmin University, Beijing, China
Shuang Hao , Department of Computing Science, TNList, Tsinghua University, Beijing, China
Jianhua Feng , Department of Computing Science, TNList, Tsinghua University, Beijing, China
ABSTRACT
Emerging vehicular trajectory data have opened up opportunities to benefit many real-world applications, e.g., frequent trajectory based navigation systems, road planning, car pooling, etc. The similarity join is a key operation to enable such applications, which finds similar trajectory pairs from two large collections of trajectories. Existing similarity metrics on trajectories rely on aligning sampling points of two trajectories. However, due to different sampling rates or different vehicular speeds, the sample points in similar trajectories may not be aligned. To address this problem, we propose a new bi-directional mapping similarity ( $_$\mathtt{BDS}$_$ ), which allows a sample point of a trajectory to align to the closest location (which may not be a sample point) on the other trajectory, and vice versa. Since it is expensive to enumerate every two trajectories and compute their similarity, we propose Strain-Join, a signature-based trajectory similarity join framework. Strain-Join first generates signatures for each trajectory such that if two trajectories do not share common signatures, they cannot be similar. In order to utilize this property to prune dissimilar pairs, we devise several techniques to generate high-quality signatures and propose an efficient filtering algorithm to prune dissimilar pairs. For the pairs not pruned by the filtering algorithm, we propose effective verification algorithms to verify whether they are similar. Experimental results on real datasets show that our algorithm outperforms state-of-the-art techniques in terms of both effectiveness and efficiency.
INDEX TERMS
Trajectory, Bidirectional control, Indexes, Public transportation, Complexity theory, Navigation, Roads
CITATION

N. Ta, G. Li, Y. Xie, C. Li, S. Hao and J. Feng, "Signature-Based Trajectory Similarity Join," in IEEE Transactions on Knowledge & Data Engineering, vol. 29, no. 4, pp. 870-883, 2017.
doi:10.1109/TKDE.2017.2651821
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