複数評価尺度に基づく道路網上での地理情報問合せ処理

抄録

Geographical information query <D, F, ψ_skyline> retrieves a subset from geographical objects D under multi-criteria, each of which is an aggregate network distance in road networks and expressed by function f_i(p, Q_i) (∈ F) where p is an geographical object and Q_i is a set of query points. ψ_skyline is skyline operation which is used to deal with multi-criteria. To process geographical information queries, Basic algorithms have been developed before. Two techniques, (1) shortest path search using path information cache and (2) incremental computation of aggregate network distances, are presented to improve processing performance of Basic algorithms. By applying both techniques to BasicLBC algorithm which is the most efficient among Basic algorithms, 2 algorithms, IncrementalLocalLBC and IncrementalGlobalLBC, are developed. Experimental results show that processing time of IncrementalGlobalLBC is reduced to 18% of that of BasicLBC, which is equal to 3% of that of BasicCE, an naive Basic algorithm.