Publication Date:
2012-10-25
Description:
Data uncertainty is inherent in emerging applications such as location-based services, sensor monitoring systems, and data integration. To handle a large amount of imprecise information, uncertain databases have been recently developed. In this paper, we study how to efficiently discover frequent itemsets from large uncertain databases, interpreted under the Possible World Semantics . This is technically challenging, since an uncertain database induces an exponential number of possible worlds. To tackle this problem, we propose a novel methods to capture the itemset mining process as a probability distribution function taking two models into account: the Poisson distribution and the normal distribution. These model-based approaches extract frequent itemsets with a high degree of accuracy and support large databases. We apply our techniques to improve the performance of the algorithms for (1) finding itemsets whose frequentness probabilities are larger than some threshold and (2) mining itemsets with the k highest frequentness probabilities. Our approaches support both tuple and attribute uncertainty models, which are commonly used to represent uncertain databases. Extensive evaluation on real and synthetic datasets shows that our methods are highly accurate and four orders of magnitudes faster than previous approaches. In further theoretical and experimental studies, we give an intuition which model-based approach fits best to different types of data sets. Content Type Journal Article Category Regular Paper Pages 1-37 DOI 10.1007/s10115-012-0561-2 Authors Thomas Bernecker, Department of Computer Science, Ludwig-Maximilians-Universität, Munchen, Germany Reynold Cheng, Department of Computer Science, University of Hong Kong, Pokfulam, Hong Kong David W. Cheung, Department of Computer Science, University of Hong Kong, Pokfulam, Hong Kong Hans-Peter Kriegel, Department of Computer Science, Ludwig-Maximilians-Universität, Munchen, Germany Sau Dan Lee, Department of Computer Science, University of Hong Kong, Pokfulam, Hong Kong Matthias Renz, Department of Computer Science, Ludwig-Maximilians-Universität, Munchen, Germany Florian Verhein, Department of Computer Science, Ludwig-Maximilians-Universität, Munchen, Germany Liang Wang, Department of Computer Science, University of Hong Kong, Pokfulam, Hong Kong Andreas Zuefle, Department of Computer Science, Ludwig-Maximilians-Universität, Munchen, Germany Journal Knowledge and Information Systems Online ISSN 0219-3116 Print ISSN 0219-1377
Print ISSN:
0219-1377
Electronic ISSN:
0219-3116
Topics:
Computer Science
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