Fuzzy Distance-Based Range Queries over Uncertain Moving Objects |
| |
Authors: | Yi-Fei Chen Xiao-Lin Qin Liang Liu Bo-Han Li |
| |
Affiliation: | (1) College of Information Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China;(2) College of Information and Control, Nanjing University of Information Science and Technology, Nanjing, 210044, China |
| |
Abstract: | Data obtained from real world are imprecise or uncertain due to the accuracy of positioning devices, updating protocols or
characteristics of applications. On the other hand, users sometimes prefer to qualitatively express their requests with vague
conditions and different parts of search region are in-equally important in some applications. We address the problem of efficiently
processing the fuzzy range queries for uncertain moving objects whose whereabouts in time are not known exactly, for which
the basic syntax is find objects always/sometimes near to the query issuer with the qualifying guarantees no less than a given threshold during
a given temporal interval. We model the location uncertainty of moving objects on the utilization of probability density functions and describe the
indeterminate boundary of query range with fuzzy set. We present the qualifying guarantee evaluation of objects, and propose
pruning techniques based on the α-cut of fuzzy set to shrink the search space efficiently. We also design rules to reject
non-qualifying objects and validate qualifying objects in order to avoid unnecessary costly numeric integrations in the refinement
step. An extensive empirical study has been conducted to demonstrate the efficiency and effectiveness of algorithms under
various experimental settings. |
| |
Keywords: | moving object uncertainty fuzzy distance-based range query |
本文献已被 CNKI SpringerLink 等数据库收录! |
|