1 Uncertainty in Spatial Trajectories Goce Trajcevski

Chapter outline 2 1.Introduction 2.Uncertainty Throughout History 3.Uncertainty in Spatial and Temporal Database 4.Modeling Uncertain Trajectories 5.Processing Spatio-Temporal Queries for Uncertain Trajectories 6.Summary Balance breadth and depth

Uncertainty Throughout History 3 1.Philosophy and Logic Epistemic Logic (BaP) Modal Logic (, ) Possible Worlds 2.Uncertainty in AI and Databases Model-Theoretic issues (Possible Models) NULLs (open vs. closed world assumption) Probabilistic databases (and possible worlds) Time Geography and Inexact Geometries Uncertain location over time Re-evaluation of Euclidian postulates

Uncertain in Spatial and Temporal Databases 4 1.Spatial Databases Imprecise Locations Impact on Queries 2.Temporal Databases Valid Time Transaction time Constructs (T-SQL)

Modeling Uncertain Trajectories 5 Location Uncertainty Models Various Sources Imprecision (GPS; Sensors) Quest for data reduction

Modeling Uncertain Trajectories 6 Cones, Beads, Necklaces

Modeling Uncertain Trajectories 7 Sheared Cylinders

Modeling Uncertain Trajectories 8 Uncertainty on Road Networks

Processing Spatio-Temporal Queries for Uncertain Trajectories 9 Query Categories Range NN Few others in potpourri Capturing the impact (of the uncertainty model) into the syntax of the query Discuss a few processing algorithms Potpourri Other predicates/issues

Processing Spatio-Temporal Queries for Uncertain Trajectories 10

Processing Spatio-Temporal Queries for Uncertain Trajectories 11

Processing Spatio-Temporal Queries for Uncertain Trajectories 12 NN-query for crisp object and uncertain-rest (cone model)

Processing Spatio-Temporal Queries for Uncertain Trajectories 13 Messing the context

Processing Spatio-Temporal Queries for Uncertain Trajectories 14 Potpourri: Alibi query Topological Predicates Inside-ness; Along-ness; Touching; Communication savings V-to-server WSN