计算机科学技术学报(英文版)
計算機科學技術學報(英文版)
계산궤과학기술학보(영문판)
JOURNAL OF COMPUTER SCIENCE AND TECHNOLOGY
2015年
4期
745-761
,共17页
陈伟%赵雷%许佳捷%刘冠锋%郑凯%周晓方
陳偉%趙雷%許佳捷%劉冠鋒%鄭凱%週曉方
진위%조뢰%허가첩%류관봉%정개%주효방
trajectory search%rating score%activity trajectory
Driven by the flourish of location-based services, trajectory search has received significant attentions in recent years. Different from existing studies that focus on searching trajectories with spatio-temporal information and text de-scriptions, we study a novel problem of searching trajectories with spatial distance, activities, and rating scores. Given a query q with a threshold of distance, a set of activities, a start point S and a destination E, trip oriented search on activity trajectory (TOSAT) returns k trajectories that can cover the activities with the highest rating scores within the threshold of distance. In addition, we extend the query with an order, i.e., order-sensitive trip oriented search on activity trajectory (OTOSAT), which takes both the order of activities in a query q and the order of trajectories into consideration. It is very challenging to answer TOSAT and OTOSAT e?ciently due to the structural complexity of trajectory data with rating infor-mation. In order to tackle the problem e?ciently, we develop a hybrid index AC-tree to organize trajectories. Moreover, the optimized variant RAC+-tree and novel algorithms are introduced with the goal of achieving higher performance. Extensive experiments based on real trajectory datasets demonstrate that the proposed index structures and algorithms are capable of achieving high e?ciency and scalability.