Updating and Querying Databases that Track Mobile Units
Distributed and Parallel Databases - Special issue on mobile data management and applications
Data Management in Location-Dependent Information Services
IEEE Pervasive Computing
Location Privacy in Pervasive Computing
IEEE Pervasive Computing
Evaluating probabilistic queries over imprecise data
Proceedings of the 2003 ACM SIGMOD international conference on Management of data
Location Based Services
The D-Tree: An Index Structure for Planar Point Queries in Location-Based Wireless Services
IEEE Transactions on Knowledge and Data Engineering
Proactive Caching for Spatial Queries in Mobile Environments
ICDE '05 Proceedings of the 21st International Conference on Data Engineering
Fuzzy Modeling with Spatial Information for Geographic Problems
Fuzzy Modeling with Spatial Information for Geographic Problems
Location-Dependent Queries in Mobile Contexts: Distributed Processing Using Mobile Agents
IEEE Transactions on Mobile Computing
Anonymous Usage of Location-Based Services Through Spatial and Temporal Cloaking
Proceedings of the 1st international conference on Mobile systems, applications and services
Spatio-Temporal Databases: Flexible Querying and Reasoning
Spatio-Temporal Databases: Flexible Querying and Reasoning
Continuous nearest neighbor search
VLDB '02 Proceedings of the 28th international conference on Very Large Data Bases
Efficient indexing methods for probabilistic threshold queries over uncertain data
VLDB '04 Proceedings of the Thirtieth international conference on Very large data bases - Volume 30
Uncertainty Reduction in Location-Based Retrieval of Georeferenced Web Resources by Moving Users
WI-IAT '09 Proceedings of the 2009 IEEE/WIC/ACM International Joint Conference on Web Intelligence and Intelligent Agent Technology - Volume 03
Geographic information retrieval: Modeling uncertainty of user's context
Fuzzy Sets and Systems
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Location-based queries (LBQ) are becoming more and more useful in location-based services (LBSs) such as those provided through mobile phones, personal digital assistants (PDAs), and laptops. They are context aware since they support the access to information by taking into account the spatial context of the user when submitting the query, and the spatial location of the searched information (instances). Generally, the key-selection condition is a constraint on the distance of the instances from the user location. One deficiency of current approaches in evaluating LBQs is the fact that they do not manage the uncertainty that often characterizes the knowledge of either the user position or the searched instances or both of them, thus they do not produce query answers with estimates of their possible validity. In the paper, after analyzing the processes involved in a LBS that may generate uncertainty, a model for representing and evaluating LBQs affected by uncertainty is proposed, in which uncertainty and imprecision can affect both location information and the spatial condition, i.e., the query scope. Distinct situations of uncertainty in LBQs are analyzed and for each of them a two-step evaluation procedure is proposed based on a fixed-cost filter phase and on a refinement phase that produces ranked results reflecting an estimate of their validity.