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國立雲林科技大學 National Yunlin University of Science and Technology 11 Discovering Personal Gazetteers: An Interactive clustering Approach Changqing Zhou, Dan Frankowski, Pamela Ludford, Shashi Shekhar, and Loren Terveen 2004.GIS Presenter : Jin-Wei Lin Advisor : Professor Chung-Chian Hsu 2007/01/17
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N.Y.U.S.T. I. M. 22 Outline Motivation Objective Introduction Approach Evaluation Framework Experiment Conclusion Comments
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N.Y.U.S.T. I. M. 33 Motivation Personal gazetteers record individuals’ most important places. There has been previous work on this problem, e.g., ad hoc algorithms, K-mean clustering, but both approaches have shortcomings.
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N.Y.U.S.T. I. M. 44 Objective This paper explores the use of novel semi- automatic techniques to discover gazetteers from users’ travel patterns.
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N.Y.U.S.T. I. M. 55 Introduction Location data storage Location sensing Cluster and visualization
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N.Y.U.S.T. I. M. 66 Approach- Exploratory Approach The loss of the GPS signal is interpreted as a significant cue, namely that a building has been entered. When the signal has been lost within a given radius on three different occasions the agent infers that this location (building) is interesting.
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N.Y.U.S.T. I. M. 77 Approach- Clustering Approach Density-based Clustering K-Mean Clustering K-Means Clustering Density-based Clustering DJ-clustering The number of clusters OXX Sensitive to noise OXX DeterministicXOO ShapeCircleArbitrary ParametersclustersEps and MinPts Efficiency---MediumFast DJ-clustering
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N.Y.U.S.T. I. M. 88 DJ-clustering P q1q1 q2q2 q3q3 Cluster C X X X X Speed greater than 0 Frequently stops Move small distance
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N.Y.U.S.T. I. M. 99 Evaluation Framework
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N.Y.U.S.T. I. M. 10 Experiment Dataset K-MeansDJ-cluster manual
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N.Y.U.S.T. I. M. 11 Conclusions We currently are in the process of analyzing the results, which will provide a useful accuracy baseline for personal gazetteer discovery algorithms. This paper proposes a deterministic, density based clustering algorithm that also uses temporal techniques to reduce the number of uninteresting places that are discovered.
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N.Y.U.S.T. I. M. 12 Comments Advantage Improve DBSCAN efficiency Drawback … Application Identify personal characteristics
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