Finding Frequent Patterns from Compressed Tree-Structured Data

  • Authors:
  • Seiji Murakami;Koichiro Doi;Akihiro Yamamoto

  • Affiliations:
  • Graduate School of Informatics, Kyoto University, Kyoto, Japan 606-8501;Graduate School of Informatics, Kyoto University, Kyoto, Japan 606-8501;Graduate School of Informatics, Kyoto University, Kyoto, Japan 606-8501

  • Venue:
  • DS '08 Proceedings of the 11th International Conference on Discovery Science
  • Year:
  • 2008

Quantified Score

Hi-index 0.00

Visualization

Abstract

In this paper we present a new method for finding frequent patterns from tree-structured data, where a frequent pattern means a subgraph which frequently occurs in a given tree-structured data. We make use of a data compression method called TGCA for tree-structured data. Improving manipulation of large scaled data by compressing them has been investigated in previous studies, such as keyword search in plain texts, and frequent itemset mining from transaction data, but it has not been applied to finding frequent patterns from tree-structured data in the best of our knowledge. The TGCA algorithm is obtained by modifying the SEQUITUR algorithm for plain texts so that it can compress tree-structured data, and we show that we can count occurrences of patterns in the original data by using the data compressed by TGCA without expanding it. This is the reason why our method improves the efficiency of finding frequent patterns. The advantage of our method is shown in some experiments in the case that the data can be compressed in some good compression ratios.