1 / 14

140 likes | 203 Vues

Query Answering on Trajectory Cuboids using Prime Numbers Encodings. Elio Masciari ICAR-CNR. IDEAS Conference Lisbon September2011. Trajectory Data Prime Numbers Encoding for Paths Warehousing Steps Experimental Evaluation Conclusions. Outline.

Télécharger la présentation
## Query Answering on Trajectory Cuboids using Prime Numbers Encodings

**An Image/Link below is provided (as is) to download presentation**
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.
Content is provided to you AS IS for your information and personal use only.
Download presentation by click this link.
While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

**Query Answering on Trajectory Cuboids using**PrimeNumbersEncodings Elio Masciari ICAR-CNR IDEAS Conference Lisbon September2011**Trajectory Data**• Prime NumbersEncodingforPaths • WarehousingSteps • ExperimentalEvaluation • Conclusions Outline**Data Pertainingtotime and position ofmovingobjects**• GPS systems • Traffic management • Twodimensional • In generalpartitioningis a wellacceptedsolution • Segmentation • Regioning Trajectory Data**Regioning**• IPCA: IdentifiesPreferredDirectionsfor Data • DifferentialRegioning • Prime NumberEncoding: • Trajectoriesrepresentedasproductsof prime numbers OurSolution: Regioning+Encoding**T1 = ABC crossingthree regions A,B,C. Assign to regions A, B**and C respectively the prime numbers 3,5,7 • For trajectory T1 the witness W1 is 52 since 52%3 = 1 = pos(A) and 52%5 = 2 = pos(B) and 52%7 = 3 = pos(C) • Store the encodedtrajectoriesusing a binarytree Encoding: prime numbers**Building Specializedcuboids:TRAC**• DistinctCountProblem • Measures • the number of distinct trajectories (Intersections), • the average traveled distance (Distance), • the averagetimeintervalduration (Duration) TrajectoryWarehousing**Precomputedcuboidspertainingtomostinterestingrecent data**• Mergingcuboids at differentgranularitylevelswhenneeded • Iceberg assumption TRACs**Data reductionbyregioning**• EfficientQueying via Encoding • Warehousing in ordertoallowtrajectoryqueryingeffectively • Goodperformances • Accuracy • Efficiency Conclusions

More Related