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71.
大型数据库中多层关联规则的挖掘算法 总被引:3,自引:0,他引:3
将基于垂直数据分布的关联规则的发现从单层概念扩展到多层概念,提出了自顶向下的、用等价类生成频繁项目集的发现算法,无需复杂的Hash数据结构。该算法减少了项目的匹配计算,提高了挖掘的效率。 相似文献
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分析了交易 (事务 )数据库中的数据结构特点 ,提出了在交易数据库中关联规则采掘的一个预处理过程 ,并且实现了该过程。通过预处理使得处理后的数据库记录个数减少了 ,从而在一定程度上提高了关联规则采掘的效率 相似文献
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75.
稠密数据库有趣规则的快速挖掘 总被引:3,自引:0,他引:3
目前,关联规则的挖掘算法主要用于非稠密数据,很少有挖掘稠密数据的算法,而现实世界中有许多数据是稠密的。由于现行的算法不适合稠 密数据的挖掘,本文定义了兴趣度函数,给出了挖掘稠密数据有趣关联的有效算法。该算法与以往不同的是提前过滤掉不满足约束的属性组合,因而提高了速度,同时,使发现的规则更有趣,更易理解。 相似文献
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78.
Efficient Graph-Based Algorithms for Discovering and Maintaining Association Rules in Large Databases 总被引:4,自引:2,他引:2
In this paper, we study the issues of mining and maintaining association rules in a large database of customer transactions.
The problem of mining association rules can be mapped into the problems of finding large itemsets which are sets of items brought together in a sufficient number of transactions. We revise a graph-based algorithm to further
speed up the process of itemset generation. In addition, we extend our revised algorithm to maintain discovered association
rules when incremental or decremental updates are made to the databases. Experimental results show the efficiency of our algorithms.
The revised algorithm is a significant improvement over the original one on mining association rules. The algorithms for maintaining
association rules are more efficient than re-running the mining algorithms for the whole updated database and outperform previously
proposed algorithms that need multiple passes over the database.
Received 4 August 1999 / Revised 18 March 2000 / Accepted in revised form 18 October 2000 相似文献
79.
This paper presents a novel global localization approach for mobile robots by exploring line-segment features in any structured environment. The main contribution of this paper is an effective data association approach, the Line-segment Relation Matching (LRM) technique, which is based on a generation and exploration of an Interpretation Tree (IT). A new representation of geometric patterns of line-segments is proposed for the first time, which is called as Relation Table. It contains relative geometric positions of every line-segment respect to the others (or itself) in a coordinate-frame independent sense. Based on that, a Relation-Table-constraint is applied to minimize the searching space of IT therefore greatly reducing the processing time of LRM. The Least Square algorithm is further applied to estimate the robot pose using matched line-segment pairs. Then a global localization system can be realized based on our LRM technique integrated with a hypothesis tracking framework which is able to handle pose ambiguity. Sufficient simulations were specially designed and carried out indicating both pluses and minuses of our system compared with former methods. We also presented the practical experiments illustrating that our approach has a high robustness against uncertainties from sensor occlusions and extraneous observation in a highly dynamic environment. Additionally our system was demonstrated to easily deal with initialization and have the ability of quick recovery from a localization failure. 相似文献
80.
Samet Çokp?nar Taflan ?mre Gündem 《Expert systems with applications》2012,39(8):7503-7511
In recent years, data mining has become one of the most popular techniques for data owners to determine their strategies. Association rule mining is a data mining approach that is used widely in traditional databases and usually to find the positive association rules. However, there are some other challenging rule mining topics like data stream mining and negative association rule mining. Besides, organizations want to concentrate on their own business and outsource the rest of their work. This approach is named “database as a service concept” and provides lots of benefits to data owner, but, at the same time, brings out some security problems. In this paper, a rule mining system has been proposed that provides efficient and secure solution to positive and negative association rule computation on XML data streams in database as a service concept. The system is implemented and several experiments have been done with different synthetic data sets to show the performance and efficiency of the proposed system. 相似文献