COMPRESSED-PREFIX TREES AND ESTDEC+ METHOD FOR FINDING FREQUENT ITEMSETS OVER DATA STREAMS

摘要

The present invention provides an effective data structure in finding frequent itemsets over data streams and finds necessary information using the data structure. The data structure proposed in the present invention is defined as a compressed prefix tree structure, and the compressed prefix tree merges or splits nodes during the mining operation by comparing the prefix tree structure applied to the conventional data mining to manage a plurality of items in a single node, thus dynamically and flexibly adjusting the tree size. Such dynamic adjustment function dynamically merges and splits nodes in the prefix tree, if the variation of itemsets that are most likely to be frequent itemsets due to the variation of the data stream, thus maximizing the accuracy of the mining result in a restricted memory space, i.e., the accuracy of frequent itemsets found.