著者
Shin-ichi Minato Kimihito Ito
出版者
The Japanese Society for Artificial Intelligence
雑誌
Transactions of the Japanese Society for Artificial Intelligence (ISSN:13460714)
巻号頁・発行日
vol.22, no.2, pp.156-164, 2007 (Released:2007-01-25)
参考文献数
17
被引用文献数
2 4

In this paper, we present a method of finding symmetric items in a combinatorial item set database. The techniques for finding symmetric variables in Boolean functions have been studied for long time in the area of VLSI logic design, and the BDD (Binary Decision Diagram) -based methods are presented to solve such a problem. Recently, we have developed an efficient method for handling databases using ZBDDs (Zero-suppressed BDDs), a particular type of BDDs. In our ZBDD-based data structure, the symmetric item sets can be found efficiently as well as for Boolean functions. We implemented the program of symmetric item set mining, and applied it to actual biological data on the amino acid sequences of influenza viruses. We found a number of symmetric items from the database, some of which indicate interesting relationships in the amino acid mutation patterns. The result shows that our method is helpful for extracting hidden interesting information in real-life databases.
著者
Shin-ichi Minato Hiroki Arimura
出版者
The Japanese Society for Artificial Intelligence
雑誌
Transactions of the Japanese Society for Artificial Intelligence (ISSN:13460714)
巻号頁・発行日
vol.22, no.2, pp.165-172, 2007 (Released:2007-01-25)
参考文献数
11
被引用文献数
1 5 9

Frequent item set mining is one of the fundamental techniques for knowledge discovery and data mining. In the last decade, a number of efficient algorithms for frequent item set mining have been presented, but most of them focused on just enumerating the item set patterns which satisfy the given conditions, and it was a different matter how to store and index the result of patterns for efficient data analysis. Recently, we proposed a fast algorithm of extracting all frequent item set patterns from transaction databases and simultaneously indexing the result of huge patterns using Zero-suppressed BDDs (ZBDDs). That method, ZBDD-growth, is not only enumerating/listing the patterns efficiently, but also indexing the output data compactly on the memory to be analyzed with various algebraic operations. In this paper, we present a variation of ZBDD-growth algorithm to generate frequent closed item sets. This is a quite simple modification of ZBDD-growth, and additional computation cost is relatively small compared with the original algorithm for generating all patterns. Our method can conveniently be utilized in the environment of ZBDD-based pattern indexing.