共查询到19条相似文献,搜索用时 62 毫秒
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当模糊规则库是稀疏型时,利用Kóczy线性插值推理方法不能保证推理结论的正规性和凸性,为了解决这一问题,石岩曾提出了插值推理方法的推理条件,当满足这些条件时利用Kóczy线性插值推理方法得到的推理结论也满足正规性和凸性;但是这些条件却限制了模糊推理系统的应用,而且如果多次推理中在同一输入点遇到稀疏情况,必须进行相同的计算才能得到正确的推理结果,这样增加了系统的计算量,降低了系统的速度和效率.因此提出了一种新的稀疏模糊推理方法,不仅能够简单的给出正确的推理结果,还能在相应的位置增加规则,提高规则库的紧密程度. 相似文献
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对基于空间关系的图像检索方法进行了全面的论述,提出了图像对象空间关系的形式化描述,通过邻近和邻近距阵以及数学期望和均方差,给出了一种在图像进行投影变换和旋转变换中保持不变的图像相似匹配算法,并为图像数据库检索提供了有力的支持。 相似文献
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WANG Li-dong 《数字社区&智能家居》2008,(21)
基于内容的图像检索CBIR(Content Based Image Retrieval)是当前多媒体检索的热点。本文提出了一种基于图像的分块主颜色的图像检索算法,论述了系统的结构、颜色特征提取方法及其相似匹配方法,并给出部分实验结果。从实验结果来看,文中提出的把图像分块再提取各分块的主色的方法,使得该系统获得了良好的检索效果。 相似文献
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在语句语义相似度计算的算法中,没有考虑语句中的不同词语对语句之间相似度值的不同贡献程度,以致计算结果不理想。为此提出了基于频率函数的改进词语相似度算法,该算法将词语在语料库中的频率函数作为权重值,引入至语句的词语相似度计算中,以降低高频率词语在语句相似度值中的比重,提高算法精确率。由于当前审计方法存在散、乱、重复等现象,为了更好地复用已有的审计方法,将根据审计方法建立审计规则库,在此基础上,利用上述改进的语义相似度算法,计算用户输入与审计规则之间的相似度值,返回满足相似度阈值条件的审计规则所对应的审计方法,用户根据所返回的审计方法,选择合适的审计方法进行审计工作。实际应用表明,该算法的应用减少了人工搜索审计方法的时间,提高了审计效率。 相似文献
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提升小波在图像检索中的应用 总被引:1,自引:0,他引:1
由于提升小波具有高效性和多分辨率等很多优越性,于是基于提升小波的图像检索方法在文中被提出.在进行特征提取的时候,为了提高效率首先把每幅图片从RGB颜色空间转换到YUV颜色空间,对于图片的每个分量(Y,U,V)都进行提升小波变换.在图像数据库建立的时候,每幅图像的小波系数都事先被存储.在进行图像匹配的时候,把被查询图片的YUV分量的小波系数和数据库中图像的小波系数进行比较,通过调整权重值来找到比较好的匹配图像.实验结果表明,给出的方法不但能够有效的提高检索效率而且还能较好地接近于人们的视觉感知结果. 相似文献
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对三维CAD模型检索研究现状进行了深入和系统的综述。CAD模型检索可划分为两个层次:基于视觉相似性的三维CAD模型检索、面向语义与功能描述的三维CAD模型检索。分别分析了两种检索层次下CAD模型的检索方法。在此基础上总结了三维CAD模型检索评测基准库、评测方法等。最后展望了现有研究中的难点及进一步的研究方向。 相似文献
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在传统工作流建模思想的基础上,通过综合考虑各种动态的需求以及流程中的可变因素,提出了一个基于自适应规则库的柔性工作流模型,并从形式化定义的角度出发,详细论述了规则库的设计及应用逻辑。在系统建模阶段尽可能对动态因素进行描述和定义,力求做到定义时的柔性,并允许工作流在执行时进行过程、角色、状态和异常定义的修改,力求做到运行时的适应性柔性,使工作流系统在建模定义的整体框架内可以动态地进行调整,从而实现工作流的动态性和自适应性。 相似文献
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Yonatan Aumann Ronen Feldman Orly Lipshtat Heikki Manilla 《Journal of Intelligent Information Systems》1999,12(1):61-73
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
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An algorithm is presented to answer window queries in a quadtree-based spatial database environment by retrieving all of the quadtree blocks in the underlying spatial database that cover the quadtree blocks that comprise the window. It works by decomposing the window operation into sub-operations over smaller window partitions. These partitions are the quadtree blocks corresponding to the window. Although a block b in the underlying spatial database may cover several of the smaller window partitions, b is only retrieved once rather than multiple times. This is achieved by using an auxiliary main memory data structure called the active border which requires O(n) additional storage for a window query of size n×n. As a result, the algorithm generates an optimal number of disk I/O requests to answer a window query (i.e., one request per covering quadtree block). A proof of correctness and an analysis of the algorithm's execution time and space requirements are given, as are some experimental results. 相似文献
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An Extension to SQL for Mining Association Rules 总被引:3,自引:2,他引:1
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Dumas Marlon Lozano Rafael Fauvet Marie-Christine Martin Hervé Scholl Pierre-Claude 《Multimedia Tools and Applications》2002,18(3):249-277
Structuration, annotation and composition are amidst the most crucial modeling issues that video editing and querying in the context of a database entail. In this paper, we propose a sequence-based, object-oriented data model that addresses them in an unified, yet orthogonal way. Thanks to this orthogonality, the interactions between these three aspects are properly captured, i.e., annotations may be attached to any level of video structuration, and all the composition operators preserve the structurations and annotations of the argument videos. We also propose to query both the structuration and the annotations of videos using an extension of ODMG's OQL which integrates a set of algebraic operators on sequences. The overall proposal is formalized and implemented on top of an object-oriented DBMS. 相似文献
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Fabio Crestani Cornelis J. van Rijsbergen 《Journal of Intelligent Information Systems》1997,8(1):29-56
The paper presents a network model that can be used toproduce conceptual and logical schemas for Information Retrievalapplications. The model has interesting adaptability characteristicsand can be instantiated in various effective ways. The paper alsoreports the results of an experimental investigation into theeffectiveness of implementing associative and adaptive retrieval onthe proposed model by means of Neural Networks. The implementationmakes use of the learning and generalisation capabilities of theBackpropagation learning algorithm to build up and use applicationdomain knowledge in a sub-symbolic form. The knowledge is acquiredfrom examples of queries and relevant documents. Three differentlearning strategies are introduced, their performance is analysed andcompared with the performance of a traditional Information Retrievalsystem. 相似文献
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Hasan M. Jamil 《Journal of Intelligent Information Systems》2002,19(2):191-206
Although knowledge discovery from large relational databases has gained popularity and its significance is well recognized, the prohibitive nature of the cost associated with extracting such knowledge, as well as the lack of suitable declarative query language support act as limiting factors. Surprisingly, little or no relational technology has yet been significantly exploited in data mining even though data often reside in relational tables. Consequently, no relational optimization has yet been possible for data mining. We exploit the transitive nature of large item sets and the so called anti-monotonicity property of support thresholds of large item sets to develop a natural least fixpoint operator for set oriented data mining from relational databases. The operator proposed has several advantages including optimization opportunities, and traditional candidate set free large item set generation. We present an SQL3 expression for association rule mining and discuss its mapping to the least fixpoint operator developed in this paper. 相似文献
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基于分布数据库的快速关联规则挖掘算法 总被引:8,自引:0,他引:8
关联规则发现是数据挖掘的重要研究内容,随着数据库中数据的不断增加,大数据集环境下的关联规则发现日益受到重视,分布式关联规则发现是解决这一问题的有效方法。分布式数据库环境下的关联规则挖掘算法中,时间开销主要体现在两方面(:1)频繁项目集的确定;(2)网络的通讯量。为了解决第一个问题,文章提出了一种基于二进制形式的候选频繁项目集生成和相应的计算支持数算法,该算法只需对挖掘对象进行一些”或”、”与”、”异或”等逻辑运算操作,显著降低了算法的实现难度。将该算法与DMA算法相结合提出改进算法FDMA。理论分析和实验结果表明,算法FDMA大大提高了关联规则挖掘的效率,算法是有效可行的。 相似文献
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发现频繁项目集是关联规则挖掘的关键问题,而发现的过程是高花费的。因此,要求对增量挖掘算法进行深入研究。这使得关联规则的更新成为数据挖掘技术中的一个重要内容。文中就关联规则的增量式更新问题进行了探讨,针对最小支持度发生变化时的增量式更新算法(IUA)的不足,提出了改进算法(AIUA),在保证算法有效的同时提高了效率。 相似文献
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入侵检测在线规则生成模型 总被引:2,自引:0,他引:2
利用机器学习算法,如SVM、神经网络等,进行入侵检测已取得很大进展,但检测结果难于理解的问题已影响到这些检测算法的广泛使用.文章在对已知的关联算法进行比较分析的基础上,提出了一种针对入侵检测结果的实时规则在线生成方法,以提高对检测结果的理解,降低入侵所带来的损失.在定义局部支持度、全局可信度、CI—Tree和IX—Tree树结构的基础上,设计了直接产生仅与当前发生的攻击相关的规则集的规则生成算法.该方法解决了当前主流关联规则生成算法应用到入侵检测结果集的过程中所存在的多遍扫描(至少两遍)、攻击数据的非均衡分布所带来的大量无效规则的产生和两阶段规则生成方法使得在第一阶段产生了众多与最后生成的规则集无关的频繁集等问题.经过实验表明,文中所提出的方法在规则生成和时间效率方面都显示出了良好的性能. 相似文献