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1.
提取图像中旋转不变特征是图像处理和模式识别中重要的应用。在极坐标下的正交矩函数则是提取这种特征信息的主要方法。正交矩函数在图像分解和重建过程中的误差是衡量其特征提取精确度的标准。为了提高正交矩函数在图像重建中的性能,提出了一种新的基于三角函数的正交矩函数和一种基于函数误差分析的新的衡量方法,并分别应用新的衡量方法和传统的在大量图像中进行重建误差统计的方法对新的正交矩函数以及另外两种在特征提取方面表现最好的正交矩函数进行了比较。实验结果验证了新的衡量方法的有效性并得到了新的正交矩函数的重建效果更好的结论。  相似文献   

2.
对人脸识别方法进行研究,提出了一种新的人脸识别方法,首先在粗糙集属性约简方法中加入LDA引入鉴别信息,构成新的特征空间。然后在新的特征空间中设计模糊神经网络分类器进行分类。在ORL人脸图像库上的实验结果表明,该方法具有良好的性能.  相似文献   

3.
核方法是机器学习中一种新的强有力的学习方法。针对核方法进行了探讨,给出了核方法的基本思想和优点。同时,描述了核方法的算法实现并举例进行了说明。  相似文献   

4.
在详细介绍ELF日志文件格式的基础上定义了会话表,并对预处理过程中几个主要步骤进行深入讨论,总结已有的各种处理手段提出新的改进方法,其中重点针对会话识别进行了改进并给出了新的算法。  相似文献   

5.
基于区域生长的网格模型分割   总被引:1,自引:1,他引:0       下载免费PDF全文
提出一种新的方法-基于法向量差值的区域生长,还提出了在候选种子中选择种子的方法,根据一种新的二面角的公式即法向量面积加权的差值进行区域生长,分割后对面积过小的面片区域进行优化处理。实验表明该方法快速有效。  相似文献   

6.
基于大津法的图像分块二值化算法   总被引:13,自引:0,他引:13  
本文对灰度图像二值化的方法进行研究,提出了一种新的以大津法为基础的图像分块二值化方法.通过对采集到的火车轮字符进行实验,结果表明了这种新的二值化方法在不均匀光照、图像模糊的情况下能很好地对图像目标(字符)进行分割,该方法的思想可以推广到对一般灰度图像的二值化中去.  相似文献   

7.
基于大津法的图像分块二值化算法   总被引:7,自引:1,他引:7  
本文对灰度图像二值化的方法进行研究,提出了一种新的以大津法为基础的图像分块二值化方法。通过对采集到的火车轮字符进行实验,结果表明了这种新的二值化方法在不均匀光照、图像模糊的情况下能很好地对图像目标(字符)进行分割,该方法的思想可以推广到对一般灰度图像的二值化中去。  相似文献   

8.
基于新的条件熵的决策树规则提取方法   总被引:9,自引:0,他引:9  
分析了知识约简过程中现有信息熵反映决策表“决策能力”的局限性,定义了一种新的条件熵,以弥补现有信息熵的不足;然后对传统启发式方法中选择属性的标准进行改进,由此给出了新的属性重要性定义;以新的属性重要性为启发式信息设计决策树规则提取方法。该方法的优点在于构造决策树及提取决策规则前不进行属性约简,计算直观,时间复杂度较低。应用实例分析的结果表明,该方法能提取更为简洁有效的决策规则。  相似文献   

9.
非接触式测量法是监测叶片振动的一项重要的新技术。为了解决非接触式测量中采样频率低的缺点,本文提出了一种新的跳越采样方法及其采样信号的数据处理方法,并通过模拟试验进行了验证。这种新的采样和信号处理方法可以在工程试验中推广应用。  相似文献   

10.
一个基于关联规则的多层文档聚类算法   总被引:3,自引:0,他引:3  
提出了一种新的基于关联规则的多层文档聚类算法,该算法利用新的文档特征抽取方法构造了文档的主题和关键字特征向量。首先在主题特征向量空间中利用频集快速算法对文档进行初始聚类,然后在基于主题关键字的新的特征向量空间中利用类间距和连接度对初始文档类进行求精,从而得到最终聚类。由于使用了两层聚类方法,使算法的效率和精度都大大提高;使用新的文档特征抽取方法还解决了由于文档关键字过多而导致文档特征向量的维数过高的问题。  相似文献   

11.
基于粗集理论的机器学习与推理   总被引:2,自引:0,他引:2  
曾黄麟 《控制与决策》1997,12(6):708-711
利用粗集理论探讨机器学习中的几个重要概念及研究方法,提出一种基于祖集理论的推理和学习方法。这种研究方法不仅开拓了一条机器学习的新途径,而且也是从数据中推理决策规则的一种新探索。  相似文献   

12.
In cost-sensitive learning, misclassification costs can vary for different classes. This paper investigates an approach reducing a multi-class cost-sensitive learning to a standard classification task based on the data space expansion technique developed by Abe et al., which coincides with Elkan's reduction with respect to binary classification tasks. Using this proposed reduction approach, a cost-sensitive learning problem can be solved by considering a standard 0/1 loss classification problem on a new distribution determined by the cost matrix. We also propose a new weighting mechanism to solve the reduced standard classification problem, based on a theorem stating that the empirical loss on independently identically distributed samples from the new distribution is essentially the same as the loss on the expanded weighted training set. Experimental results on several synthetic and benchmark datasets show that our weighting approach is more effective than existing representative approaches for cost-sensitive learning.  相似文献   

13.
Extensive research has been performed for developing knowledge based intelligent monitoring systems for improving the reliability of manufacturing processes. Due to the high expense of obtaining knowledge from human experts, it is expected to develop new techniques to obtain the knowledge automatically from the collected data using data mining techniques. Inductive learning has become one of the widely used data mining methods for generating decision rules from data. In order to deal with the noise or uncertainties existing in the data collected in industrial processes and systems, this paper presents a new method using fuzzy logic techniques to improve the performance of the classical inductive learning approach. The proposed approach, in contrast to classical inductive learning method using hard cut point to discretize the continuous-valued attributes, uses soft discretization to enable the systems have less sensitivity to the uncertainties and noise. The effectiveness of the proposed approach has been illustrated in an application of monitoring the machining conditions in uncertain environment. Experimental results show that this new fuzzy inductive learning method gives improved accuracy compared with using classical inductive learning techniques.  相似文献   

14.
基于不完备信息系统的Rough Set决策规则提取方法   总被引:2,自引:0,他引:2  
对象信息的不完备性是从实例中归纳学习的最大障碍。针对不完备的信息,研究了基于不完备信息系统的粗糙集决策规则提取方法,利用分层递减约简算法,通过实例有效地分析和处理了含有缺省数据和不精确数据的信息系统,扩展了粗糙集的应用领域。  相似文献   

15.
16.
Lazy Learning of Bayesian Rules   总被引:19,自引:0,他引:19  
The naive Bayesian classifier provides a simple and effective approach to classifier learning, but its attribute independence assumption is often violated in the real world. A number of approaches have sought to alleviate this problem. A Bayesian tree learning algorithm builds a decision tree, and generates a local naive Bayesian classifier at each leaf. The tests leading to a leaf can alleviate attribute inter-dependencies for the local naive Bayesian classifier. However, Bayesian tree learning still suffers from the small disjunct problem of tree learning. While inferred Bayesian trees demonstrate low average prediction error rates, there is reason to believe that error rates will be higher for those leaves with few training examples. This paper proposes the application of lazy learning techniques to Bayesian tree induction and presents the resulting lazy Bayesian rule learning algorithm, called LBR. This algorithm can be justified by a variant of Bayes theorem which supports a weaker conditional attribute independence assumption than is required by naive Bayes. For each test example, it builds a most appropriate rule with a local naive Bayesian classifier as its consequent. It is demonstrated that the computational requirements of LBR are reasonable in a wide cross-section of natural domains. Experiments with these domains show that, on average, this new algorithm obtains lower error rates significantly more often than the reverse in comparison to a naive Bayesian classifier, C4.5, a Bayesian tree learning algorithm, a constructive Bayesian classifier that eliminates attributes and constructs new attributes using Cartesian products of existing nominal attributes, and a lazy decision tree learning algorithm. It also outperforms, although the result is not statistically significant, a selective naive Bayesian classifier.  相似文献   

17.
This paper proposes a new hybrid approach for recurrent neural networks (RNN). The basic idea of this approach is to train an input layer by unsupervised learning and an output layer by supervised learning. In this method, the Kohonen algorithm is used for unsupervised learning, and dynamic gradient descent method is used for supervised learning. The performances of the proposed algorithm are compared with backpropagation through time (BPTT) on three benchmark problems. Simulation results show that the performances of the new proposed algorithm exceed the standard backpropagation through time in the reduction of the total number of iterations and in the learning time required in the training process.  相似文献   

18.
匹配树和决策树方法识别英语句子中的BaseNP   总被引:2,自引:1,他引:1  
提出了语料库和机器学习相结合的方法识别英语句子中的简单的、非递归的名词短语(BaseNP),在含有词性标注和BaseNP边界标注的训练语料中,抽取所有不同类型BaseNP短语对应的词性序列(BaseNP规则),通过规则排序和语方学知识,对其中正确率低且明显不符合语法的规则进行剔除,在识别时,采取规则匹配树的方法进行最大长度匹配,通过归纳机器学习C4.5自满引入上下文信息,由C4.5算法学习出有效(  相似文献   

19.
一种基于Rough Set理论的属性约简及规则提取方法   总被引:133,自引:1,他引:132  
常犁云  王国胤  吴渝 《软件学报》1999,10(11):1206-1211
该文针对Rough Set理论中属性约简和值约简这两个重要问题进行了研究,提出了一种借助于可辨识矩阵(discernibility matrix)和数学逻辑运算得到最佳属性约简的新方法.同时,借助该矩阵还可以方便地构造基于Rough Set理论的多变量决策树.另外,对目前广泛采用的一种值约简策略进行了改进,最终使得到的规则进一步简化.  相似文献   

20.
属性约简是粗糙集理论中的重要研究内容之一.但属性约简是一个NP难题,需要通过启发式知识实四。文中提出利用分辨矩阵求不同的条件属性组合相对于决策属性的正域的方法,并给出新的求核属性的方法。在此基础上,提出了一种利用分辨矩阵实现属性约简的新算法,该算法能快速求最少属性且实现简单,并实现了属性约简与规则提取的同步.最后通过实例证明了其正确性。  相似文献   

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