多分类器组合及其应用于手写体数字识别

在许多模式识别的应用中经常遇到这样的问题:组合多个分类器.提出了一种新的组合多个分类器的方法,这个方法由反向传播神经网络来控制,一个无标号的模式输入到每一个单独的分类器,它也同时输入到神经网络中来决定哪两个分类器作为冠军和亚军.让这两个分类器通过一个随机数发生器来决定最终的胜者.并且将这个方法应用到识别手写体数字.实验显示单个分类器的性能能够得到可观的改变.     

基于表格查寻学习算法的自适应模糊分类器

以手写体数字识别问题为背景,提出了一种基于表格查寻学习算法的自适应模糊分类 器,并用Matlab给出了自适应模糊分类器的实现,进而对其进行了仿真。仿真结果表明,该自适应模 糊分类器在手写体数字识别的识别性能、利用语言信息、计算复杂性等方面均优于采用BP算法的三 层前馈分类器,体现了自适应模糊处理技术用于模式识别的优越性和潜力。     

Class-specific feature polynomial classifier for pattern classification and its application to handwritten numeral recognition

The polynomial classifier (PC) that takes the binomial terms of reduced subspace features as inputs has shown superior performance to multilayer neural networks in pattern classification. In this paper, we propose a class-specific feature polynomial classifier (CFPC) that extracts class-specific features from class-specific subspaces, unlike the ordinary PC that uses a class-independent subspace. The CFPC can be viewed as a hybrid of ordinary PC and projection distance method. The class-specific features better separate one class from the others, and the incorporation of class-specific projection distance further improves the separability. The connecting weights of CFPC are efficiently learned class-by-class to minimize the mean square error on training samples. To justify the promise of CFPC, we have conducted experiments of handwritten digit recognition and numeral string recognition on the NIST Special Database 19 (SD19). The digit recognition task was also benchmarked on two standard databases USPS and MNIST. The results show that the performance of CFPC is superior to that of ordinary PC, and is competitive with support vector classifiers (SVCs).     

基于多分类器组合的笔迹验证

运用多分类器组合技术和模糊技术将多种笔迹鉴别方法按一定规则进行融合，针对笔迹鉴别中的笔迹验证问题进行应用。实验结果表明，融合后笔迹验证准确率有大幅的提高     

灵敏度正则化极限学习机及其在数字识别中的应用

针对正则化极限学习机（RELM）中隐节点数影响分类准确性问题,提出一种灵敏度正则化极限学习机（SRELM）算法.首先根据隐含层激活函数的输出及其相对应的输出层权重系数,推导实际值与隐节点输出值残差相对于隐节点的灵敏度计算公式,然后根据不同隐节点的灵敏度进行排序,利用优化样本的分类准确率删减次要隐节点,从而有效提高SRELM的分类准确率.MNIST手写体数字库实验结果表明,相比于传统的SVM和RELM, SRELM方法的耗时与RELM相差不大,均明显低于SVM, SRELM对手写数字的识别准确率最高.     

Correlation‐based classifier combination in the field of pattern recognition

Classifier combination methods have proved to be an effective tool to increase the performance of classification techniques that can be used in any pattern recognition applications. Despite a significant number of publications describing successful classifier combination implementations, the theoretical basis is still not matured enough and achieved improvements are inconsistent. In this paper, we propose a novel statistical validation technique known as correlation‐based classifier combination technique for combining classifier in any pattern recognition problem. This validation has significant influence on the performance of combinations, and their utilization is necessary for complete theoretical understanding of combination algorithms. The analysis presented is statistical in nature but promises to lead to a class of algorithms for rank‐based decision combination. The potentials of the theoretical and practical issues in implementation are illustrated by applying it on 2 standard datasets in pattern recognition domain, namely, handwritten digit recognition and letter image recognition datasets taken from UCI Machine Learning Database Repository ( http://www.ics.uci.edu/_mlearn ). 1 An empirical evaluation using 8 well‐known distinct classifiers confirms the validity of our approach compared to some other combinations of multiple classifiers algorithms. Finally, we also suggest a methodology for determining the best mix of individual classifiers.     

手写混合字符集识别的多特征多级分类器设计

针对常用的银行汉字和阿拉伯数字混合字符集的识别,提出了依据不同的分类要求，分别选取不同的分类特征，并采用先聚类再用多层感知器(MLP)神经网络分类的多级分类器进行识别的设计方法。实验结果表明，该方法用于手写体混合字符集的识别是行之有效的。     

A hierarchical multiple classifier learning algorithm

This paper addresses the classification problem for applications with extensive amounts of data and a large number of features. The learning system developed utilizes a hierarchical multiple classifier scheme and is flexible, efficient, highly accurate and of low cost. The system has several novel features: (1) It uses a graph-theoretic clustering algorithm to group the training data into possibly overlapping cluster, each representing a dense region in the data space; (2) component classifiers trained on these dense regions are specialists whose probabilistic outputs are gated inputs to a super-classifier. Only those classifiers whose training clusters are most related to an unknown data instance send their outputs to the super-classifier; and (3) sub-class labelling is used to improve the classification of super-classes. The learning system achieves the goals of reducing the training cost and increasing the prediction accuracy compared to other multiple classifier algorithms. The system was tested on three large sets of data, two from the medical diagnosis domain and one from a forest cover classification problem. The results are superior to those obtained by several other learning algorithms.     

离线签名验证中的多分类器集成

在离线签名验证的分类器设计中,为了减少特征向量分布不均和维数过高对实验结果的影响,给出一种多分类器集成的方法.根据特征向量数量级的不同进行分组,各组分类器自适应地确定分类器权重,通过投票表决得出集成判决结果.实验结果表明,通过分组和加权后,分类正确率有明显提高.     

手写体字符识别的多特征多分类器设计

特征选取和分类器设计是字符识别系统设计的关键。文章针对手写体汉字和阿拉伯数字混和字符集的识别提出了依据不同的分类要求,分别选取不同的字符特征并采用神经网络多分类器进行识别的设计方法。实验结果表明,该方法用于手写体混合字符集的识别是行之有效的。     

Plurality voting-based multiple classifier systems: statistically independent with respect to dependent classifier sets

The simultaneous use of multiple classifiers has been shown to provide performance improvement in classification problems. The selection of an optimal set of classifiers is an important part of multiple classifier systems and the independence of classifier outputs is generally considered to be an advantage for obtaining better multiple classifier systems. In this paper, the need for the classifier independence is interrogated from classification performance point of view. The performance achieved with the use of classifiers having independent joint distributions is compared to some other classifiers which are defined to have best and worst joint distributions. These distributions are obtained by formulating the combination operation as an optimization problem. The analysis revealed several important observations about classifier selection which are then used to analyze the problem of selecting an additional classifier to be used with the available multiple classifier system.     

手写体数字有效鉴别特征的抽取与识别

文中提出了基于后验概率估计的多特征多分类器组合识别的估计法,并提出了基于具有统计不相关性的最佳鉴别变换与ＫＬ变换抽取手写体数字的有效鉴别特征的方法。实验采用Ｃｏｎｃｏｒｄｉａ Ｕｎｉｖｅｒｓｉｔｙ ＣＥＮＰＡＲＭＩ手写体数字数据库。用最近邻距离分类器与最近邻相关分类器这两个分类器,对手写体数字的１２个特征做多特征多分类器组合识别实验。实验结果表明：估计法优于常用的投票法与计分法,估计法的识别率高达     

Choosing a discernibility measure for reject-option of individual and multiple classifiers

A novel method for evaluating the reliability of a classifier on a pattern is proposed based on the discernibility of a pattern's class against other classes from the pattern. Three measures of discernibility are proposed and experimentally compared with each other and with more conventional techniques based on the classification scores for class labels. The classification accuracy can be significantly enhanced through discernibility measures using the most reliable – ‘elite’ – patterns. It can be further boosted by forming an amalgamation of the elites of different classifiers. Improved performance is achieved at the price of rejecting many patterns. There are situations in which this price is worth paying – when the non-reliable predictions, however good, lead to the need for the manual testing of very cumbersome and complex technical devices or in diagnostics of human terminal diseases. Contrary to conventional techniques for estimating reliability, the proposed measures are applicable to small datasets as well as to datasets with complex class structures on which conventional classifiers show low accuracy rates.     

信息检索方法在手写数字识别中的应用及改进

本文首先将文本信息检索中LSI方法的思想和原理应用于手写数字识别问题,把手写数字图像看作空间向量的表示,通过计算未知数字与各训练集之间相关度排序来达到识别的目的,计算量小且有较低的误识率(5.5%);其次,通过对所有0-9数字的训练样本排列为一个矩阵,并对该矩阵进行奇异值分解,将各训练样本在适当维数的左奇异向量上分别投影,得到了一种低阶表示下的相关度计算方法,该方法在保持原有较低误识率的同时,能极大地压缩原有训练样本数据(压缩掉的数据百分比超过95%);另外,利用了区分不规范样本的思想,获得了更低的误识率(下降到4.5%)。     

基于专家域的多层分类器融合

论文提出了一种基于专家域的多层分类器融合模型,专家指不同专长之单分类器。模型思想来自医院诊断流程,模型首先训练n个专家,之后将样本空间按专家专长划分专家域。对于待测样本,先将样本指派到合适的专家域,然后再由指定的专家对样本进行分类。用这种算法对UCI的标准数据集进行分类,实验结果显示,该算法得到比其他算法更低的分类误差,显著提高了分类器的性能。     

基于类条件置信变换的后验概率估计方法

后验概率估计是模式识别多分类器组合方法研究的基础,该文提出了最近邻距离分类器后验概率估计的类条件置信变换方法．后验概率被认为集中在最近邻类与次近邻类上,而且对每一个模式类,都有一个类条件置信变换函数,该函数可以通过实验数据估计得到．实验采用Concordia大学CENPARMI手写体数字数据库与南京理工大学手写体数字数据库．实验结果表明该文所提出的类条件置信变换方法是合理的,在降低识别错误率上,优于现有的投票法、记分法、线性法以及自适应置信变换(ACT)法．     

高维数据多级模糊模式识别的分类研究*

通过分析对象属性间的关系,提出了一种基于改进的多级模糊模式识别的分类方法。该方法重点考虑对象属性间影响较大的因素,以此建立影响对象分类的属性之间的简化关系,使分类结果更加合理;针对分类标准为对象属性分类的离散值,存在对象属性值介于中间状态不便分类问题,通过建立属性值所属级别的矩阵来确定属性权重,使分类精确;利用Rough集的特征属性约简算法降低数据集的维数,提高高维数据的分类效率。经实例证明该方法分类准确、效率高。     

一个新的多分类器组合模型

分类在数据挖掘中扮演着很重要的角色,然而单个分类器有很多缺点,包括适用范围十分有限和分类准确度不高等。把多个单分类器的分类结果融合起来是克服这些缺点的有效途径,因此存在很高的研究价值。组合多分类器的一个核心内容是融合规则,现存的融合规则有积规则、和规则、中值规则与投票规则等,但这些规则性能还不够稳定。提出了一个新的基于神经网络的融合规则,并依此建立一个新的多分类器组合模型,实验表明它能提高分类准确度和稳定性。     

手写粉笔数字自动识别方法研究

手写粉笔字在生产生活中应用广泛,针对手写粉笔字易与背景混淆的特点,提出了手写粉笔数字自动识别方法,分别通过粉笔字普适性分割算法和基于SVM的手写数字分层分类自动识别技术解决了分割和识别两个关键问题,并结合钢材板坯号自动识别系统的应用进行方法的实验,达到了较高的识别率,具有重大的应用价值和推广意义。     

A computational model for recognition of multifont word images

A computational model for the recognition of multifont machine-printed word images of highly variable quality is given. The model integrates three word-recognition algorithms, each of which utilizes a different form of shape and context information. The approaches are character-recognition-based, segmentation-based, and word-shape-analysis based. The model overcomes limitations of previous solutions that focus on isolated characters. In an experiment using a lexicon of 33,850 words and a test set of 1,671 highly variable word images, the algorithm achieved a correct rate of 89% at the top choice and 95% in the top ten choices.