A collaborative approach to moving k-nearest neighbor queries in directed and dynamic road networks

In this paper, we investigate a new approach to moving k-nearest neighbor (MkNN) queries in directed and dynamic road networks, where each road segment has a particular orientation and its travel time changes depending on traffic conditions. An MkNN query continuously finds the k nearest neighbors (NNs) of a moving query object. Most existing studies have focused on MkNN queries in undirected and static road networks, where each road segment is bidirectional and its travel time does not change over time. However, little attention has been paid to MkNN queries in directed and dynamic road networks. In this research, we propose COMET, a collaborative approach to Moving k nEaresT neighbor queries in directed and dynamic road networks, where query processing is performed through collaboration between the server and query objects. In addition, we conduct extensive experiments to show that COMET substantially outperforms a conventional method in terms of query response time, bandwidth usage, and energy consumption. (C) 2014 Elsevier B.V. All rights reserved.