Abstract
In this paper, we present a new type of spatial queries called Nearest Surrounder (NS) queries. An NS query determines the nearest polygon-shaped spatial objects (referred to as nearest surrounder objects) and their orientations with respect to a query point from an object set. Besides, we derive two NS query variants, namely, multitier NS (m-NS) queries and angle-constrained NS (ANS) queries. An m-NS query searches multiple layers of NS objects for the same range of angles from a query point. An ANS query searches for NS objects within a specified range of angles. To evaluate NS queries and their variants, we explore angle-based and distance-based bound properties of polygons, and devise two efficient algorithms, namely, Sweep and Ripple, based on R-tree. The algorithms access objects in an order according to their orientations and distances with respect to a given query point, respectively. They are efficient as they can finish a search with one index lookup. Besides, they can progressively deliver a query result. Through empirical studies, we evaluate the proposed algorithms and report their performance for both synthetic and real object sets.
Original language | English |
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Article number | 5184841 |
Pages (from-to) | 1444-1458 |
Number of pages | 15 |
Journal | IEEE Transactions on Knowledge and Data Engineering |
Volume | 22 |
Issue number | 10 |
DOIs | |
Publication status | Published - 19 Jul 2010 |
Keywords
- Algorithms.
- Nearest surrounder queries
- R-tree
- Spatial query processing
ASJC Scopus subject areas
- Information Systems
- Computer Science Applications
- Computational Theory and Mathematics