Online mining frequent closed itemsets over data stream

Based on the algorithm LossCounting, a novel approach called LossyCounting_Closed(LC_Closed ) for mining closed frequent itemsets over data stream was proposed. A new summary data structure called Closed-Itemsets-forest (CI-forest) was developed for maintaining only closed frequent itemsets.The insertion and query of closed itemsets can be rapidly made based on the data structure CI-forest, and the location of the associated historical closed itemsets in the stage of dealing with the new transaction is also facilitated by CI-forest. Since the algorithm maintains closed itemsets online, the current closed frequent itemsets can be output in real time based on user-s specified thresholds. The effectiveness of the proposed method is shown in the experimental results.