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1.
采用神经网络群构成的分类器解决实景交通标志识别问题时,识别率普遍较低.分析可知,颜色复杂性造成的颜色失真是影响识别率的主要因素.遵循"简化复杂问题、基于颜色信息、采用智能方法"的基本思路,提出了一种新的解决方案:先通过颜色规格化方法将交通标志中复杂的颜色信息简化为5种基本颜色,然后再利用两级智能分类器实现分类.采用BP网络实现了颜色规格化;实验表明,这种方法具有很好的鲁棒性. 相似文献
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Breast cancer is the most common type of cancer among women. As early detection is crucial for the patient’s health, much attention has been paid to the development of tools for effective recognition of this disease. This article presents an application of image analysis and classification methods for fine needle biopsy. In our approach, each patient is described by nine microscopic images taken from the biopsy sample. The images are related to regions of the biopsy that seem interesting to the physician who selects them arbitrarily. We propose four different hybrid segmentation algorithms dedicated to processing these images and examine their effectiveness for the nuclei feature extraction task. Classification is carried out with the usage of a classifier ensemble based on the Random Subspaces approach. To boost its effectiveness, we use a linear combination of the support functions returned by the individual classifiers in the ensemble. In the proposed medical support system, the final decision about the patient is delivered after a fusion of nine separate outputs of the classifier – each for a different image. Experimental results carried out on a diverse dataset collected by the authors prove that the proposed solution outperforms state-of-the-art classifiers and shows itself to be a valuable tool for supporting day-to-day cytologist’s routine. 相似文献
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基于改进的BP网络模型的分类器的设计与实现 总被引:8,自引:3,他引:5
王文剑 《计算机工程与设计》1997,18(5):43-45
用改进的BP网络模型作了分类器。改进的模型拓扑结构最简,学习速率快,分类准确率高。 相似文献
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本文提出了一种用于神经元模式分类器学习的进化计算算法。该算法综合了非确定有限自动机和次群体的动态数据结构,可有效地完成神经网络模式分类器的结构学习,以获得最优的求解结果。该算法的有效性已由计算机仿真实验所证实,可被认为是一种很有发展前途的模式分类系统的机器学习算法。 相似文献
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Guobin Ou 《Pattern recognition》2007,40(1):4-18
Multi-class pattern classification has many applications including text document classification, speech recognition, object recognition, etc. Multi-class pattern classification using neural networks is not a trivial extension from two-class neural networks. This paper presents a comprehensive and competitive study in multi-class neural learning with focuses on issues including neural network architecture, encoding schemes, training methodology and training time complexity. Our study includes multi-class pattern classification using either a system of multiple neural networks or a single neural network, and modeling pattern classes using one-against-all, one-against-one, one-against-higher-order, and P-against-Q. We also discuss implementations of these approaches and analyze training time complexity associated with each approach. We evaluate six different neural network system architectures for multi-class pattern classification along the dimensions of imbalanced data, large number of pattern classes, large vs. small training data through experiments conducted on well-known benchmark data. 相似文献
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一种新的RBF神经元网络分类算法 总被引:1,自引:1,他引:1
为了改善对人工神经网络行为的认识和研究中的"黑匣子"式的难以处理的状态,基于RBF神经元模型的几何解释,提出了一种新的RBF神经网络分类算法,算法把RBF神经元看作是高维空间里的超球面,从而将神经网络训练问题转化为点集"包含"问题.同传统的RBF网络相比,算法能够自动地优化RBF网络中核函数的个数、中心和宽度,同时,省去了传统RBF神经网络输出层线性连接权的计算,简化了网络的学习过程,大大缩短了训练时间,并且通过实验证明了算法的有效性. 相似文献
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神经网络VC维计算研究 总被引:3,自引:0,他引:3
1 引言神经网络技术已经在很多领域得到了成功的应用.但由于神经网络并不具有一个统一的理论框架,其经验性成分相当高,这对其进一步发展造成了极大的阻碍。如果能为神经网络应用提供一些指导性的分析方法,不仅将促进该领域的理论研究,还可以在应用 相似文献
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Julien Meynet Author Vitae Jean-Philippe Thiran Author Vitae 《Pattern recognition》2010,43(10):3412-174
Combining several classifiers has proved to be an effective machine learning technique. Two concepts clearly influence the performances of an ensemble of classifiers: the diversity between classifiers and the individual accuracies of the classifiers. In this paper we propose an information theoretic framework to establish a link between these quantities. As they appear to be contradictory, we propose an information theoretic score (ITS) that expresses a trade-off between individual accuracy and diversity. This technique can be directly used, for example, for selecting an optimal ensemble in a pool of classifiers. We perform experiments in the context of overproduction and selection of classifiers, showing that the selection based on the ITS outperforms state-of-the-art diversity-based selection techniques. 相似文献
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Licheng Jiao Author Vitae Author Vitae 《Pattern recognition》2006,39(4):587-594
Kernel Matching Pursuit Classifier (KMPC), a novel classification machine in pattern recognition, has an excellent advantage in solving classification problems for the sparsity of the solution. Unfortunately, the performance of the KMPC is far from the theoretically expected level of it. Ensemble Methods are learning algorithms that construct a collection of individual classifiers which are independent and yet accurate, and then classify a new data point by taking vote of their predictions. In such a way, the performance of classifiers can be improved greatly. In this paper, on a thorough investigation into the principle of KMPC and Ensemble Method, we expatiate on the theory of KMPC ensemble and pointed out the ways to construct it. The experiments performed on the artificial data and UCI data show KMPC ensemble combines the advantages of KMPC with ensemble method, and improves classification performance remarkably. 相似文献
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Tatt Hee Oong Author VitaeNor Ashidi Mat IsaAuthor Vitae 《Applied Soft Computing》2012,12(4):1303-1308
This paper presents a new method called one-against-all ensemble for solving multiclass pattern classification problems. The proposed method incorporates a neural network ensemble into the one-against-all method to improve the generalization performance of the classifier. The experimental results show that the proposed method can reduce the uncertainty of the decision and it is comparable to the other widely used methods. 相似文献
13.
细胞识别是图像处理和模式识别领域的一个研究热点,有着十分广泛的应用前景。本文提出了基于神经网络算法FTART2的肺癌细胞识别方法,讨论了FTART2的网络结构、输入矢量的标准化及分类算法。用513个样本对网络进行训练,再用716个样本组成测试集进行测试,实验结果表明:本文提出的基于FTART2的肺癌细胞分类器与基于标准BP的分类器相比,具有学习速度快、分类精度高的特点。 相似文献
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面对多样化的应用环境,卷积神经网络(CNN)的架构深度不断增加以提升精度,但同时需要大量的计算参数和网络存储。针对CNN卷积层参数冗余和运算效率低的问题,提出一种基于分层阈值的自适应动态剪枝方法。设计自适应分层阈值判断算法,对批归一化层的尺度因子进行聚类分析,自适应地找到每层的分类断点并据此确定最终阈值,利用该阈值修剪正则化后的输入模型,从而避免根据经验人为定义固定阈值,减小模型尺寸和运行时占用的内存。分别采用该方法和LIU等提出的使用固定阈值且全局修剪的方法对VGGNet、ResNet、DenseNet和LeNet模型进行压缩,并在CIFAR、SVHN和MNIST数据集上测试模型性能。实验结果表明,该方法能够在模型精度与剪枝率之间找到最优平衡,剪枝后模型的测试错误率较对比方法降低0.02~1.52个百分点,同时自适应分层阈值判断算法也能避免对比方法在全局修剪时减去整个层的问题。 相似文献
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选择性集成通过选择部分基分类器参与集成,从而提高集成分类器的泛化能力,降低预测开销.但已有的选择性集成算法普遍耗时较长,将数据挖掘的技术应用于选择性集成,提出一种基于FP-Tree(frequent pattern tree)的快速选择性集成算法:CPM-EP(coverage based pattern mining for ensemble pruning).该算法将基分类器对校验样本集的分类结果组织成一个事务数据库,从而使选择性集成问题可转化为对事务数据集的处理问题.针对所有可能的集成分类器大小,CPM-EP算法首先得到一个精简的事务数据库,并创建一棵FP-Tree树保存其内容;然后,基于该FP-Tree获得相应大小的集成分类器.在获得的所有集成分类器中,对校验样本集预测精度最高的集成分类器即为算法的输出.实验结果表明,CPM-EP算法以很低的计算开销获得优越的泛化能力,其分类器选择时间约为GASEN的1/19以及Forward-Selection的1/8,其泛化能力显著优于参与比较的其他方法,而且产生的集成分类器具有较少的基分类器. 相似文献
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Over the past decades, regularization theory is widely applied in various areas of machine learning to derive a large family of novel algorithms. Traditionally, regularization focuses on smoothing only, and does not fully utilize the underlying discriminative knowledge which is vital for classification. In this paper, we propose a novel regularization algorithm in the least-squares sense, called discriminatively regularized least-squares classification (DRLSC) method, which is specifically designed for classification. Inspired by several new geometrically motivated methods, DRLSC directly embeds the discriminative information as well as the local geometry of the samples into the regularization term so that it can explore as much underlying knowledge inside the samples as possible and aim to maximize the margins between the samples of different classes in each local area. Furthermore, by embedding equality type constraints in the formulation, the solutions of DRLSC can follow from solving a set of linear equations and the framework naturally contains multi-class problems. Experiments on both toy and real world problems demonstrate that DRLSC is often superior in classification performance to the classical regularization algorithms, including regularization networks, support vector machines and some of the recent studied manifold regularization techniques. 相似文献
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人工神经网络的自适应结构学习(AdaNet)是基于Boosting集成学习的神经结构搜索框架,可通过集成子网创建高质量的模型。现有的AdaNet所产生的子网之间的差异性不显著,因而限制了集成学习中泛化误差的降低。在AdaNet设置子网网络权重和集成子网的两个步骤中,使用Adagrad、RMSProp、Adam、RAdam等自适应学习率方法来改进现有AdaNet中的优化算法。改进后的优化算法能够为不同维度参数提供不同程度的学习率缩放,得到更分散的权重分布,以增加AdaNet产生子网的多样性,从而降低集成学习的泛化误差。实验结果表明,在MNIST(Mixed National Institute of Standards and Technology database)、Fashion-MNIST、带高斯噪声的Fashion-MNIST这三个数据集上,改进后的优化算法能提升AdaNet的搜索速度,而且该方法产生的更加多样性的子网能提升集成模型的性能。在F1值这一评估模型性能的指标上,改进后的方法相较于原方法,在三种数据集上的最大提升幅度分别为0.28%、1.05%和1.10%。 相似文献
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多层前馈模糊神经网络进行图像识别 总被引:1,自引:0,他引:1
神经网络和模糊技术在模式识别领域中已有了广泛应用,两者有着各自的优势。针对神经网络模式识别中所遇到的问题,为了进一步提高分类器在样本分布不清晰情况下的识别能力,本文提出了两各将模糊机制引入神经网络的方法-输入模糊化方法和隐层模糊化方法,并在此基础上分别构造了模糊神经网络。实验结果表明,模糊神经网络较好地结合了神经网络和模糊技术的优点,取得了比传统网络更好的识别结果。 相似文献
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针对复杂卷积神经网络(CNN)在中小型人脸数据库中的识别结果容易出现过拟合现象,提出一种基于改进CNN网络与集成学习的人脸识别算法。改进CNN网络结合平面网络和残差网络的特点,采用平均池化层代替全连接层,使得网络结构简单且可移植性强。在改进CNN网络的基础上,利用基于投票法的集成学习策略将所有个体学习器结果凸组合为最终结果,实现更准确的人脸识别。实验结果表明,该算法在Color FERET、AR和ORL人脸数据库上的识别准确率分别达到98.89%、99.67%和100%,并且具有较快的收敛速度。 相似文献
20.
介绍由16位CPU,动态RAM阵列,训练分类等逻辑组成的印刷体汉字识别部件的设计原理和管理软件。 相似文献