| dc.description.abstract | Mining association rules with multiple minimum supports is an important generalization of the association rule mining problem, which was recently proposed by Liu et al. Instead of setting a single minimum support threshold for all items, they allow users to specify multiple minimum supports to reflect the natures of the items and their varied frequencies in the database. In Liu’s paper, an Apriori-based algorithm, named MSapriori, is developed to mine all frequent item sets. In this paper, we study the same problem but with two additional improvements. First, we propose a FP-tree-like structure, MIS-tree, to store the crucial information about frequent patterns. Accordingly, an efficient MIS-tree-based algorithm, called the CFP-growth algorithm, is developed for mining all frequent item sets. We evaluate the performance of the algorithm using both synthetic datasets and real datasets, and the results show that the CFP-growth algorithm is much more efficient and scalable than the MSapriori algorithm. Second, since each item can have its own minimum support, it is very difficult for users to set the appropriate thresholds for all items at a time. In practice, users need to tune items’ supports and run the mining algorithm repeatedly until a satisfactory end is reached. To speed up this time-consuming tuning process, an efficient algorithm which can maintain the MIS-tree structure without rescanning database is proposed. Experiments on both synthetic and real-life datasets show that our MIS-tree maintenance algorithm achieves dramatic saving in computation when tuning supports. | en_US |