Fast discovery of frequent closed sequential patterns based on positional data

Frequent closed sequential patterns mining is one of the hot topics in data mining. In this paper, a novel frequent closed sequential pattern mining algorithm, FCSM-PD (frequent closed sequential pattern mining algorithm based on positional data) is proposed, which is the improved BIDE algorithm based on the positional data. The positional data is used to reserve the position information of items in the algorithm, By storing all the position information of the prefix sequences in advance, the verifying about the existence of extension of position with a prefix sequence can be easily implemented by scanning the position information of the prefix sequence, rather than scanning the pseudo-projected database repeatedly in the BI-Directional Extension closure checking scheme, which is the most consumed time phase in the algorithm of BIDE. Meanwhile optimization strategy is applied to reduce the time and memory cost in the mining process. The experimental results show that FCSM-PD costs significantly lower running time than BIDE, especially in the intensive database.