Efficient Processing of Moving Top‐k Spatial Keyword Queries in Directed and Dynamic Road Networks

Abstract

A top-k spatial keyword (TkSk) query ranks objects based on the distance to the query location and textual relevance to the query keywords. Several solutions have been proposed for top-k spatial keyword queries. However, most of the studies focus on Euclidean space or only investigate the snapshot queries where both the query and data object are static. A few algorithms study TkSk queries in undirected road networks where each edge is undirected and the distance between two points is the length of the shortest path connecting them. However, TkSk queries have not been thoroughly investigated in directed and dynamic spatial networks where each edge has a particular orientation and its weight changes according to the traffic conditions. Therefore, in this study, we address this problem by presenting a new method, called COSK, for processing continuous top-k spatial keyword queries for moving queries in directed and dynamic road networks. We first propose an efficient framework to process snapshot TkSK queries. Furthermore, we propose a safe-exit-based approach to monitor the validity of the results for moving TkSK queries. Our experimental results demonstrate that COSK significantly outperforms existing techniques in terms of query processing time and communication cost.

Efficient processing of top-k frequent spatial keyword queries

“…Most of the existing research works employ specific hybrid index structures to index spatial information and textual information, respectively, and design retrieval algorithms to answer TkSKQ. For spatial information indexing, R-tree 15 and its variants are the most common ones 1,2,4,6,[19][20][21][22] . Cary et al 2 propose a hybrid Spatial-Keyword Index (SKI) for spatial textual data; it combines R-tree with inverted indices to maintain spatial and textual information of the spatial object.…”

“…Cong et al 1 and Li et al 6 combine R-tree with inverted files to develop a hybrid index structure IR-tree for spatial object dataset. And Rocha-Junior et al 21 and Attique et al 22 tries to develop the hybrid index structures including R-tree, inverted files, and others to answer TkSKQ in Road network. In addition, quadtree 23 is also employed for indexing spatial textual data.…”

Geo-Social Top-k and Skyline Keyword Queries on Road Networks

“…Guo et al [6] investigated the problem of continuous top-k spatial keyword queries on road networks and proposed two algorithms to monitor continuous top-k keyword queries incrementally that minimize the expansion of the network edges. Attique et al [21] recently expanded the problem and proposed a safe region based approach to monitor moving top-k keyword queries in directed and dynamic road networks, where each network edge is directed and its traveling cost depends on the traffic conditions.…”