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1.
一种优化相关规划的发现方法   总被引:5,自引:0,他引:5  
提出了一种基于相关性的框架.在此框架内,使用残差分析来判断两项之间是否是独立的.残差分析可以使得我们很容易地获得包含负蕴含规则在内的真正的关联(而不是并发)规则,而且不需要指定支持度和可信度阈值.为了提高发现规则的质量,文中使用遗传算法来发现优化规则.在人工数据集和真实数据集上的实验结果表明文中的算法在发现规则的有趣性上优于类Apriori算法.  相似文献   

2.
从不同的角度分析了属性约简的两种重要方法:区分矩阵法和基于属性重要性。根据数据集的实际情况提出了一种基于粗糙集的区分矩阵和属性重要性相结合的启发式算法,并获得了属性约简集。在约简集的基础上分析了静态决策推理规则及算法。在相容决策系统中利用集合向量包含度构造了规则融合的方法,从而得到动态条件规则的极大近似决策值。在知识满足分类质量要求的前提下,根据规则融合方法,对任意给定的样本知识可以判别知识的实际归属类。  相似文献   

3.
从不同的角度分析了属性约简的两种重要方法:区分矩阵法和基于属性重要性.根据数据集的实际情况提出了一种基于粗糙集的区分矩阵和属性重要性相结合的启发式算法,并获得了属性约简集.在约简集的基础上分析了静态决策推理规则及算法.在相容决策系统中利用集合向量包含度构造了规则融合的方法,从而得到动态条件规则的极大近似决策值.在知识满足分类质量要求的前提下,根据规则融合方法,对任意给定的样本知识可以判别知识的实际归属类.  相似文献   

4.
数字属性的优化关联规则开采   总被引:2,自引:0,他引:2  
关联规则揭示了关系表中属性之间潜在的联系,优化关联规则是发现特定属性间用户最感兴趣关系的一种有效途径。该文提出了一种基于数字属性的优化关税规则开采算法,该算法允许优化关联规则包含多维析取范式。  相似文献   

5.
文中提出了一种基于遗传算法的生成隶属度函数的方法,该方法通过遗传算法对初始种群进行优化,获得一个适应度较高的隶属度函数编码,然后再根据机场噪声数据的实际标准对优化后得到的隶属度函数进行修正,进而得到梯形分布的隶属度函数编码.最后通过得到的隶属度函数对数据进行模糊化,并采用FP-trees算法生成模糊关联规则.该文针对数量型属性提出了这种方法,它的优点是能够使通过遗传算法得到的较优的隶属度函数更加适用于实际的数据集.  相似文献   

6.
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   

7.
研究了利用Bayes定理发现分类规则的方法,用Bayes定理可以发现分类规则,然后用分类规则进行数据分类。结合实例针对概念性数据集及包含数值性属性和概念性属性的数据集两种情况进行讨论。通过实例说明Bayes定理是数据挖掘中一种有效的数据分类方法。  相似文献   

8.
传统关联规则挖掘方法通常产生海量杂乱的规则,它们对用户而言是冗余的.为解决该问题,文中提出一种基于信息熵的兴趣度规则挖掘算法.通过变量相关性分析剔除原始规则集中虚假、错误的规则,并在信息熵的基础上提出度量关联规则兴趣度的框架.该算法不依赖用户先验知识,能无偏地表达数据包含的信息.在真实和仿真数据集上的实验验证该算法能有效挖掘兴趣度规则,且性能比传统算法更优.  相似文献   

9.
提出了一种结合Apriori和Kuok's算法的改进的模糊关联规则算法.在定义隶属函数、决策树结构和规则集相似度的基础上,采用改进的挖掘算法挖掘数值属性的关联规则.实验结果表明,算法在规则生成和时间效率方面都显示了良好的性能.  相似文献   

10.
关联规则挖掘是数据挖掘的重要领域之一,利用粗糙集理论来挖掘关联规则的方法已经得到广泛关注.针对不完备信息系统,提出了基于粗糙集理论的快速ORD关联规则挖掘算法.该算法首先采用基于粗糙集理论的属性约简算法进行属性约简,然后采用快速、高效的冗余项集和冗余规则修剪算法--ORD算法获取关联规则.将该算法与其它同类流行的算法在4个UCI数据集上进行实验比较,结果表明该算法性能良好.  相似文献   

11.
Mining optimized gain rules for numeric attributes   总被引:7,自引:0,他引:7  
Association rules are useful for determining correlations between attributes of a relation and have applications in the marketing, financial, and retail sectors. Furthermore, optimized association rules are an effective way to focus on the most interesting characteristics involving certain attributes. Optimized association rules are permitted to contain uninstantiated attributes and the problem is to determine instantiations such that either the support, confidence, or gain of the rule is maximized. In this paper, we generalize the optimized gain association rule problem by permitting rules to contain disjunctions over uninstantiated numeric attributes. Our generalized association rules enable us to extract more useful information about seasonal and local patterns involving the uninstantiated attribute. For rules containing a single numeric attribute, we present an algorithm with linear complexity for computing optimized gain rules. Furthermore, we propose a bucketing technique that can result in a significant reduction in input size by coalescing contiguous values without sacrificing optimality. We also present an approximation algorithm based on dynamic programming for two numeric attributes. Using recent results on binary space partitioning trees, we show that the approximations are within a constant factor of the optimal optimized gain rules. Our experimental results with synthetic data sets for a single numeric attribute demonstrate that our algorithm scales up linearly with the attribute's domain size as well as the number of disjunctions. In addition, we show that applying our optimized rule framework to a population survey real-life data set enables us to discover interesting underlying correlations among the attributes.  相似文献   

12.
Mining optimized association rules with categorical and numericattributes   总被引:1,自引:0,他引:1  
Mining association rules on large data sets has received considerable attention in recent years. Association rules are useful for determining correlations between attributes of a relation and have applications in marketing, financial, and retail sectors. Furthermore, optimized association rules are an effective way to focus on the most interesting characteristics involving certain attributes. Optimized association rules are permitted to contain uninstantiated attributes and the problem is to determine instantiations such that either the support or confidence of the rule is maximized. In this paper, we generalize the optimized association rules problem in three ways: (1) association rules are allowed to contain disjunctions over uninstantiated attributes, (2) association rules are permitted to contain an arbitrary number of uninstantiated attributes, and (3) uninstantiated attributes can be either categorical or numeric. Our generalized association rules enable us to extract more useful information about seasonal and local patterns involving multiple attributes. We present effective techniques for pruning the search space when computing optimized association rules for both categorical and numeric attributes. Finally, we report the results of our experiments that indicate that our pruning algorithms are efficient for a large number of uninstantiated attributes, disjunctions, and values in the domain of the attributes  相似文献   

13.
《Information Systems》2001,26(6):425-444
Mining association rules on large data sets have received considerable attention in recent years. Association rules are useful for determining correlations between attributes of a relation and have applications in marketing, financial and retail sectors. Furthermore, optimized association rules are an effective way to focus on the most interesting characteristics involving certain attributes. Optimized association rules are permitted to contain uninstantiated attributes and the problem is to determine instantiations such that either the support, confidence or gain of the rule is maximized. In this paper, we generalize the optimized support association rule problem by permitting rules to contain disjunctions over uninstantiated numeric attributes. Our generalized association rules enable us to extract more useful information about seasonal and local patterns involving the uninstantiated attribute. For rules containing a single numeric attribute, we present a dynamic programming algorithm for computing optimized association rules. Furthermore, we propose bucketing technique for reducing the input size, and a divide and conquer strategy that improves the performance significantly without sacrificing optimality. We also present approximation algorithms based on dynamic programming for two numeric attributes. Our experimental results for a single numeric attribute indicate that our bucketing and divide and conquer enhancements are very effective in reducing the execution times and memory requirements of our dynamic programming algorithm. Furthermore, they show that our algorithms scale up almost linearly with the attribute's domain size as well as the number of disjunctions.  相似文献   

14.
We consider the problem of finding association rules in a database with binary attributes. Most algorithms for finding such rules assume that all the data is available at the start of the data mining session. In practice, the data in the database may change over time, with records being added and deleted. At any given time, the rules for the current set of data are of interest. The naive, and highly inefficient, solution would be to rerun the association generation algorithm from scratch following the arrival of each new batch of data. This paper describes the Borders algorithm, which provides an efficient method for generating associations incrementally, from dynamically changing databases. Experimental results show an improved performance of the new algorithm when compared with previous solutions to the problem.  相似文献   

15.
新型决策树构造方法   总被引:1,自引:0,他引:1       下载免费PDF全文
决策树是一种重要的数据挖掘工具,但构造最优决策树是一个NP-完全问题。提出了一种基于关联规则挖掘的决策树构造方法。首先定义了高可信度的近似精确规则,给出了挖掘这类规则的算法;在近似精确规则的基础上产生新的属性,并讨论了新生成属性的评价方法;然后利用新生成的属性和数据本身的属性共同构造决策树;实验结果表明新的决策树构造方法具有较高的精度。  相似文献   

16.
关联规则挖掘是数据挖掘领域中的重要研究内容之一。然而,传统的基于支持度-可信度框架的挖掘方法可能会产生大量不相关、甚至是误导的关联规则。针对现有关联规则挖掘的评价标准存在的问题,提出在评价标准中增加兴趣度,并给出了兴趣度的定义和基于兴趣度的关联规则挖掘算法。利用兴趣度将关联规则分为正关联规则和负关联规则,从而可以用算法挖掘带有负项的关联规则。实验结果分析表明,在传统挖掘方法的基础上引入兴趣度,可以有效地减少正关联规则的规模,产生有意义的负关联规则。  相似文献   

17.
关联规则挖掘是数据挖掘领域中的重要研究内容之一。然而,传统的基于支持度-可信度框架的挖掘方法可能会产生大量不相关、甚至是误导的关联规则。针对现有关联规则挖掘的评价标准存在的问题,提出在评价标准中增加兴趣度,并给出了兴趣度的定义和基于兴趣度的关联规则挖掘算法。利用兴趣度将关联规则分为正关联规则和负关联规则,从而可以用算法挖掘带有负项的关联规则。实验结果分析表明,在传统挖掘方法的基础上引入兴趣度,可以有效地减少正关联规则的规模,产生有意义的负关联规则。  相似文献   

18.
空间关联规则的双向挖掘   总被引:9,自引:0,他引:9  
空间数据库中关联规则挖掘不仅需要考虑关系元组属性之间的关系——纵向关系,更需要挖掘元组之间的关系——横向关系,如相邻、相交、重叠等。本文通过分析空间数据库的存储模式,借鉴事务数据库关联规则的挖掘方法,对空间关联规则进行完整定义,并对规则的兴趣度度量进行探讨。根据挖掘的方向将空间数据挖掘归纳为纵向挖掘、横向挖掘、双向挖掘。在双向挖掘中,提出一种新算法,该算法根据挖掘任务进行约束,缩小挖掘空间,然后通过空间计算将空间关系转化为非空间关系,经过多次循环,获取非空间项集,进而挖掘出空间关联规则。据此提出空间数据双向挖掘工作流程,并通过实例进行了验证。  相似文献   

19.
Given a huge database, we address the problem of finding association rules for numeric attributes, such as(BalanceI)⇒(CardLoan=yes),which implies that bank customers whose balances fall in a rangeIare likely to use card loan with a probability greater thanp. The above rule is interesting only if the rangeIhas some special feature with respect to the interrelation betweenBalanceandCardLoan. It is required that the number of customers whose balances are contained inI(called thesupportofI) is sufficient and also that the probabilitypof the conditionCardLoan=yesbeing met (called theconfidence ratio) be much higher than the average probability of the condition over all the data. Our goal is to realize a system that finds such appropriate ranges automatically. We mainly focus on computing twooptimized ranges: one that maximizes the support on the condition that the confidence ratio is at least a given threshold value, and another that maximizes the confidence ratio on the condition that the support is at least a given threshold number. Using techniques from computational geometry, we present novel algorithms that compute the optimized ranges in linear time if the data are sorted. Since sorting data with respect to each numeric attribute is expensive in the case of huge databases that occupy much more space than the main memory, we instead apply randomized bucketing as the preprocessing method and thus obtain an efficient rule-finding system. Tests show that our implementation is fast not only in theory but also in practice. The efficiency of our algorithm enables us to compute optimized rules for all combinations of hundreds of numeric and Boolean attributes in a reasonable time.  相似文献   

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