数据流是随着时间顺序快速变化的和连续的,对其进行频繁模式挖掘时会出现概念漂移现象.在一些数据流应用中,通常认为最新的数据具有最大的价值.数据流挖掘会产生大量无用的模式,为了减少无用模式且保证无损压缩,需要挖掘闭合模式.因此,...数据流是随着时间顺序快速变化的和连续的,对其进行频繁模式挖掘时会出现概念漂移现象.在一些数据流应用中,通常认为最新的数据具有最大的价值.数据流挖掘会产生大量无用的模式,为了减少无用模式且保证无损压缩,需要挖掘闭合模式.因此,提出了一种基于时间衰减模型和闭合算子的数据流闭合模式挖掘方式TDMCS(Time-Decay-Model-based Closed frequent pattern mining on data Stream).该算法采用时间衰减模型来区分滑动窗口内的历史和新近事务权重,使用闭合算子提高闭合模式挖掘的效率,设计使用最小支持度-最大误差率-衰减因子的三层架构避免概念漂移,设计一种均值衰减因子平衡算法的高查全率和高查准率.实验分析表明该算法适用于挖掘高密度、长模式的数据流;且具有较高的效率,在不同大小的滑动窗口条件下性能表现是稳态的,同时也优于其他同类算法.展开更多
Mining frequent patterns has been studied popularly in data mining area. However, little work has been done on mining patterns when the database has an influx of fresh data constantly. In these dynamic scenarios, effi...Mining frequent patterns has been studied popularly in data mining area. However, little work has been done on mining patterns when the database has an influx of fresh data constantly. In these dynamic scenarios, efficient maintenance of the discovered patterns is crucial. Most existing methods need to scan the entire database repeatedly, which is an obvious disadvantage. In this paper, an efficient incremental mining algorithm, Incremental-Mining (IM), is proposed for maintenance of the frequent patterns when incremental data come. Based on the frequent pattern tree (FP-tree) structure, IM gives a way to make the most of the things from the previous mining process, and requires scanning the original data once at most. Furthermore, IM can identify directly the differential set of frequent patterns, which may be more informative to users. Moreover, IM can deal with changing thresholds as well as changing data, thus provide a full maintenance scheme. IM has been implemented and the performance study shows it outperforms three other incremental algorithms: FUP, DB-tree and re-running frequent pattern growth (FP-growth). Keywords data mining - association rule mining - frequent pattern mining - incremental mining Supported by the National Basic Research 973 Program of China under Grant No.G1999032705.Xiu-Li Ma received the Ph.D. degree in computer science from Peking University in 2003. She is currently a postdoctoral researcher at National Lab on Machine Perception of Peking University. Her main research interests include data warehousing, data mining, intelligent online analysis, and sensor network.Yun-Hai Tong received the Ph.D. degree in computer software from Peking University in 2002. He is currently an assistant professor at School of Electronics Engineering and Computer Science of Peking University. His research interests include data warehousing, online analysis processing and data mining.Shi-Wei Tang received the B.S. degree in mathematics from Peking University in 1964. Now, he is a professor and Ph.D. su展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.60473075 60773063 (国家自然科学基金)+2 种基金the Key Program National Natural Science Foundation of China under Grant No.60533110 (国家自然科学基金重点项目)the National Basic Research Program of China under Grant No.2006CB303000 (国家重点基础研究发展计划(973))the Program for New Century Excellent Talents in University (NCET) under Grant No.NCET-05-0333 (新世纪优秀人才支持计划)
文摘数据流是随着时间顺序快速变化的和连续的,对其进行频繁模式挖掘时会出现概念漂移现象.在一些数据流应用中,通常认为最新的数据具有最大的价值.数据流挖掘会产生大量无用的模式,为了减少无用模式且保证无损压缩,需要挖掘闭合模式.因此,提出了一种基于时间衰减模型和闭合算子的数据流闭合模式挖掘方式TDMCS(Time-Decay-Model-based Closed frequent pattern mining on data Stream).该算法采用时间衰减模型来区分滑动窗口内的历史和新近事务权重,使用闭合算子提高闭合模式挖掘的效率,设计使用最小支持度-最大误差率-衰减因子的三层架构避免概念漂移,设计一种均值衰减因子平衡算法的高查全率和高查准率.实验分析表明该算法适用于挖掘高密度、长模式的数据流;且具有较高的效率,在不同大小的滑动窗口条件下性能表现是稳态的,同时也优于其他同类算法.
文摘Mining frequent patterns has been studied popularly in data mining area. However, little work has been done on mining patterns when the database has an influx of fresh data constantly. In these dynamic scenarios, efficient maintenance of the discovered patterns is crucial. Most existing methods need to scan the entire database repeatedly, which is an obvious disadvantage. In this paper, an efficient incremental mining algorithm, Incremental-Mining (IM), is proposed for maintenance of the frequent patterns when incremental data come. Based on the frequent pattern tree (FP-tree) structure, IM gives a way to make the most of the things from the previous mining process, and requires scanning the original data once at most. Furthermore, IM can identify directly the differential set of frequent patterns, which may be more informative to users. Moreover, IM can deal with changing thresholds as well as changing data, thus provide a full maintenance scheme. IM has been implemented and the performance study shows it outperforms three other incremental algorithms: FUP, DB-tree and re-running frequent pattern growth (FP-growth). Keywords data mining - association rule mining - frequent pattern mining - incremental mining Supported by the National Basic Research 973 Program of China under Grant No.G1999032705.Xiu-Li Ma received the Ph.D. degree in computer science from Peking University in 2003. She is currently a postdoctoral researcher at National Lab on Machine Perception of Peking University. Her main research interests include data warehousing, data mining, intelligent online analysis, and sensor network.Yun-Hai Tong received the Ph.D. degree in computer software from Peking University in 2002. He is currently an assistant professor at School of Electronics Engineering and Computer Science of Peking University. His research interests include data warehousing, online analysis processing and data mining.Shi-Wei Tang received the B.S. degree in mathematics from Peking University in 1964. Now, he is a professor and Ph.D. su
