关键词: 数据挖掘, 数据流, 频繁项集, 滑动窗口, 矩阵

Abstract: According to the mobility and flowing of data streams，an algorithm called NSW is proposed to mine the frequent itemsets from a sliding window over data streams，and it meets the needs of people getting the frequent itemsets over datas arrived in recently.The binary matrix representation is adopted in the proposed algorithm to express the transaction list from a sliding window.The oldest transaction is deleted directly，and not generating the candidate itemsets but generating the frequent itemsets directly.These methods greatly control the space and time.The experiment results show that this algorithm has a good performance in speed and space.

Key words: data mining, data stream, frequent itemsets, sliding window, matrix