Title
Efficient Order-Sensitive Activity Trajectory Search.
Abstract
In this paper, we study the problem of order-sensitive activity trajectory search. Given a query containing a set of time-order target locations, the problem is to find the most suitable trajectory from the trajectory database such that the resulting trajectory can achieve the minimum distance from the query. We formulate the problem using two different order-sensitive distance functions: the sum-up objective function, and the maximum objective function. For the sum-up objective function, we propose a dynamic programming (DP) algorithm with time complexity (O(mn^2)) where m is the length of the trajectory and n is the number of query locations. To improve the efficiency, we also propose an improved DP algorithm. For the maximum objective function, we propose exact and approximation algorithms to tackle it. The approximation algorithm achieves a near-optimal performance ratio, and it improves the time complexity from (O(mn^2)) to (O(nlog (d/epsilon ))) in comparison with the DP algorithm. Extensive experimental studies over both synthetic and real-world datasets demonstrate the efficiency and effectiveness of our approaches.
Year
Venue
Field
2017
WISE
Data mining,Approximation algorithm,Dynamic programming,Performance ratio,Computer science,Algorithm,Trajectory database,Time complexity,Trajectory
DocType
Citations 
PageRank 
Conference
0
0.34
References 
Authors
18
6
Name
Order
Citations
PageRank
Kaiyang Guo100.34
Rong-Hua Li238133.77
Shaojie Qiao320125.93
Zhenjun Li400.68
Weipeng Zhang5378.00
Minhua Lu6594.01