关键词: 数据挖掘, 频繁项集, 频繁闭项集, 单向FP-tree, 被约束子树

Abstract: Frequent closed itemsets provide a minimal representation of frequent itemsets without losing their support information.This paper proposes an efficient algorithm Unid_FP-FCI for mining the complete set of frequent closed itemsets in a unidirectional FP-tree.Because in process of mining only generate constrained sub-trees consisting of three small arrays，which is pseudo tree structure based on the originally unidirectional FP-tree，the flaw is avoided in former algorithms which need to generate lots of conditional FP-trees for finding frequent closed itemsets recursively.Reducing the space and time consumption to a great extent，then the algorithm improve mining efficiency.

Key words: data mining, frequent itemset, frequent closed itemset, unidirectional FP-tree, constrained sub-tree