Uncertainty in Spatial Trajectories
Goce Trajcevski
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Chapter outline
1.
2.
3.
4.
5.
Introduction
Uncertainty Throughout History
Uncertainty in Spatial and Temporal Database
Modeling Uncertain Trajectories
Processing Spatio-Temporal Queries for Uncertain
Trajectories
6. Summary
Balance breadth and depth
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Uncertainty Throughout History
1.
2.
Philosophy and Logic
Time Geography and Inexact
• Epistemic Logic (BaP)
Geometries
• Modal Logic (,)
• Uncertain location over
• Possible Worlds
time
Uncertainty in AI and Databases
• Re-evaluation of Euclidian
• Model-Theoretic issues (Possible Models)
postulates
• NULLs (open vs. closed world assumption)
• Probabilistic databases (and possible worlds)
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Uncertain in Spatial and Temporal Databases
1.
Spatial Databases
• Imprecise Locations
• Impact on Queries
2.
Temporal Databases
• Valid Time
• Transaction time
• Constructs (T-SQL)
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Modeling Uncertain Trajectories
Location Uncertainty Models
Various Sources’ Imprecision
(GPS; Sensors)
Quest for data reduction
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Modeling Uncertain Trajectories
•
Cones, Beads, Necklaces
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Modeling Uncertain Trajectories
Sheared Cylinders
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Modeling Uncertain Trajectories
Uncertainty on Road
Networks
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Processing Spatio-Temporal Queries for
Uncertain Trajectories
• 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
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Processing Spatio-Temporal Queries for
Uncertain Trajectories
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Processing Spatio-Temporal Queries for
Uncertain Trajectories
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Processing Spatio-Temporal Queries for
Uncertain Trajectories
NN-query for crisp object and uncertain-rest
(cone model)
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Processing Spatio-Temporal Queries for
Uncertain Trajectories
“Messing” the context
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Processing Spatio-Temporal Queries for
Uncertain Trajectories
Potpourri:
• Alibi query
• Topological Predicates
• Inside-ness;
• Along-ness;
• Touching;
• Communication savings
• V-to-server
• WSN
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