气体传感器阵列常用模式识别算法

模式识别在气体传感器阵列的测量中占有举足轻重的地位。介绍了k近邻法、聚类分析、判别函数分析、反向传播人工神经网络、主元分析法、概率神经网、学习向量量化、自组织映射、自适应共振网、遗传算法等气体传感器阵列常用模式识别算法的原理和特点。同时,指出了在应用中模式识别算法选择和评价的标准。     

改进的小脑控制神经网络算法研究

研究小脑控制器神经网络(CMAC)在模式识别中的应用问题.在算法优化过程中,针对模式识别中训练样本中存在着高维、大量冗余信息而传统CMAC不能够对输入信息空间维数降低,从而常导致CMAC网络训练速度慢、识别率低等问题.为了加快CMAC学习速度,提高识别率,提出一种基于粗糙集(RS)的CMAC模式识别方法(RS_CMAC).利用粗糙集约简并删除训练样本中的冗余信息,降低样本的维数,从而优化网络的结构;同时网络中引入了自适应动态学习率,加快网络的收敛速度和学习速度,从而提高识别率.以数码管模式识别为例对算法进行了验证性实验,仿真结果表明,与传统CMAC相比.识别精度有了明显提高,学习速度加快.RS_CMAC方法克服了传统CMAC缺点和不足,是一种有效的模式识别方法,为实际应用提供依据.     

BP网络学习算法研究及其图像模式识别应用

BP神经网络的训练性能主要包括收敛速度和收敛精度等方面,该训练性能在很大程度上取决于所选择的网络学习算法。本文针对模式识别应用领域,通过实例,运用Matlab编程对部分较好的网络学习算法的训练性能进行了比较研究．给出了模式识别应用过程中BP网络学习算法的选择依据。在此基础上,运用BP网络编程实现了对常见单位符号图像目标的模式识别,并通过识别算法的实现过程,分析了用BP网络进行图像目标模式识别的具体思路和方法。     

基于量子小波神经网络的传动装置模式识别

针对传统神经网络收敛精度低,以及用于故障模式识别能力差的问题,提出了将量子神经网络与小波理论相结合的量子小波神经网络模型.该模型隐层量子神经元采用小波基函数的线性叠加作为激励函数,给出了网络学习算法,并以某型传动装置监测信号的小波能量谱为训练样本,识别传动装置带有缺损的齿轮故障征兆.仿真结果表明,量子小波神经网络能够提高神经网络训练精度和故障征兆识别精度.     

非线性迭代PLS信息模式识别算法

对偏最小二乘(PLS)回归的基本方法进行了分析研究,提出了基于非线性迭代偏最小二乘(NIPLS)的信息模式识别算法。该算法实现了模式识别中特征提取与分类器设计的有机结合。NIPLS较Fisher判别分析、Bayes判别分析等经典的模式识别算法,具有更强的信息识别能力,且对数据本身的分布要求不高,尤其对于多重共线性资料或解释变量多而样本数量少时更为有效。将该算法应用于土地质量的分类识别,结果表明,该文所建立的算法是有效的、可靠的。     

改进PSO优化神经网络算法的人体姿态识别

为了提高人体姿态的识别精度,提出一种基于改进的粒子群优化(PSO)神经网络的人体姿态识别算法.采用加速度传感器获取加速度信息,并在常用特征集的基础上,加入离散系数和曲线积分两种新特征作为神经网络的输入;在利用PSO神经网络参数的同时,通过控制概率,自适应地对粒子进行遗传操作,增强粒子跳出局部极小值的能力;采用训练后的神经网络对6种人体姿态进行识别.实验结果表明:该算法收敛速度和全局寻优能力得到了提高,与其他经典算法相比识别精度更高.     

基于遗传算法和BP网络的文字识别方法

将基于遗传的BP神经网络算法用于文字识别算法结合了遗传算法和BP网络的优点.先采用遗传学习算法进行全局寻优、再利用BP算法进行精确训练、优化BP(Back Propagation)神经网络权重学习和训练的神经网络文字识别算法.实验结果表明该算法完全达到了文字识别要求,识别率达到了98%.并且在识别速度上也明显优于传统的BP神经网络及其他改进算法,具有精确性、收敛性和识别速度快等特点.     

一种基于叶分量分析的带有监督信息的在线学习方法

在一些模式识别应用中,具有类属信息的样本数量较少,此时监督学习算法会遇到小样本问题,导致分类器的识别精度大幅低于预期水平.基于叶分量分析,提出一种带监督信息的在线学习方法.该方法在训练过程进行监督学习,而在模式识别阶段能够在对输入样本进行分类的同时基于这些样本进行非监督在线学习,因此实现了监督学习与非监督学习的结合.在小本量情况下,在线学习可以弥补训练阶段监督学习的不足,仍能保证获得较高的识别精度.实验证明,该方法能够有效克服小样本问题.     

人耳和侧面人脸融合的多模态身份识别

首先分别对人耳和侧面人脸建立基于全空间线性判别分析(FSLDA)的分类器;然后采用贝叶斯决策理论中常见的积、和、中值多分类器融合算法,并对投票算法进行了改进.实验结果表明,与单一的人耳或侧面人脸特征识别比较,人耳和侧面人脸融合的多模态识别率得到提高,并扩大了识别范围.     

基于非监督学习神经网络的自动调制识别研究与实现

以非监督学习神经网络为主要研究对象,描述自组织网络的基本模型,分析传统自组织网络的训练算法,提出了一种基于自组织特征映射SOFM(Self-Organizing Feature Map)神经网络的通信信号自动调制识别方法。方法改进了训练算法中的学习率函数和邻域函数,提高了算法的收敛速度和性能,并将其应用在通信信号调制识别中。仿真实验检验基于SOFM神经网络的调制识别方法的性能,并与后向反馈(BP)神经网络加以比较,结果表明SOFM神经网络的调制识别方法具有较高的识别精度,改进后的训练算法提高了识别的有效性。     

Probabilistic neural networks and the polynomial Adaline ascomplementary techniques for classification

Two methods for classification based on the Bayes strategy and nonparametric estimators for probability density functions are reviewed. The two methods are named the probabilistic neural network (PNN) and the polynomial Adaline. Both methods involve one-pass learning algorithms that can be implemented directly in parallel neural network architectures. The performances of the two methods are compared with multipass backpropagation networks, and relative advantages and disadvantages are discussed. PNN and the polynomial Adaline are complementary techniques because they implement the same decision boundaries but have different advantages for applications. PNN is easy to use and is extremely fast for moderate-sized databases. For very large databases and for mature applications in which classification speed is more important than training speed, the polynomial equivalent can be found.     

新一代线速网络关键问题的研究

随着因特网的高速发展,因特网主干需要具备多业务能力的G位、甚至T位路由器。这就使得数据包输入处理成为主干路由器的瓶颈。本文分析了这一问题传统的纯软件算法解决方案,指出了其存在的历史局限性：传统的算法只适用于具有大内存和比较强的处理能力的计算机;进而本文提出了应着眼于设计新的硬件体系结构来解决这一问题,最后本文总结提出了三种非软件的解决方法和思路：发展新的CAM和TCAM设计工艺、基于人工神经网络的解决方法、基于协处理器的解决方法。     

Classification of binary document images into textual or nontextual data blocks using neural network models

This paper describes a new method for the classification of binary document images as textual or nontextual data blocks using neural network models. Binary document images are first segmented into blocks by the constrained run-length algorithm (CRLA). The component-labeling procedure is used to label the resulting blocks. The features for each block, calculated from the coordinates of its extremities, are then fed into the input layer of a neural network for classification. Four neural networks were considered, and they include back propagation (BP), radial basis functions (RBF), probabilistic neural network (PNN), and Kohonen's self-organizing feature maps (SOFMs). The performance and behavior of these neural network models are analyzed and compared in terms of training times, memory requirements, and classification accuracy. The experiments carried out on a variety of medical journals show the feasibility of using the neural network approach for textual block classification and indicate that in terms of both accuracy and training time RBF should be preferred.     

基于神经网络的变压器故障诊断方法研究

针对概率神经网络(PNN)模型强大的非线性分类能力,PNN能够很好地对变压器故障进行分类;文章通过对PNN神经网络的结构和原理的分析,应用PNN概率神经网络方法对变压器故障进行诊断;通过实例仿真表明,PNN网络的训练时间比BP网络少,比之预测准确度也要高,而且还具有高度的泛化能力,这使得PNN网络可以有效地运用到变压器故障诊断中,具有一定的可操作性。     

结合概率型神经网络(PNN)和学习矢量量化(LVQ)算法的文本分类方法

针对文本自动分类问题,提出一种基于概率型神经网络(PNN)和学习矢量量化(LVQ)相结合的文本分类算法,该方法借助TFIDF方法提取文本特征及特征值,形成文本分类特征向量,利用概率型神经网络构建分类模型,并利用LVQ学习算法对神经网络模型竞争层网络进行学习,使相应模式向量相互靠拢,远离其他模式,从而实现文本分类.实验结果表明,提出的该方法在文本分类中表现了很好的效果,不仅具有很好的分类准确率,还表现出很好的学习效率.     

基于纳米ZnO气体传感器阵列的乙醇、丙酮、苯、甲苯、二甲苯的识别研究

采用6个不同掺杂的纳米ZnO气体传感器组成的阵列实现了乙醇、丙酮、苯、甲苯、二甲苯的识别。研究表明，掺杂可大幅度提高传感器的敏感度和对可挥发有机物（Vocs）的选择性。对比了k近邻法、线性判别法、反传人工神经网络、概率神经网络、学习向量量化等在本实验中的应用。反传人工神经网络具有最高识别率，可达100％。本研究表明电子鼻在空气质量监测中具有广阔的应用前景。     

Probabilistic neural network for breast cancer classification

Among cancers, breast cancer causes second most number of deaths in women. To reduce the high number of unnecessary breast biopsies, several computer-aided diagnosis systems have been proposed in the last years. These systems help physicians in their decision to perform a breast biopsy on a suspicious lesion seen in a mammogram or to perform a short-term follow-up examination instead. In clinical diagnosis, the use of artificial intelligent techniques as neural networks has shown great potential in this field. In this paper, three classification algorithms, multi-layer perceptron (MLP), radial basis function (RBF) and probabilistic neural networks (PNN), are applied for the purpose of detection and classification of breast cancer. Decision making is performed in two stages: training the classifiers with features from Wisconsin Breast Cancer database and then testing. The performance of the proposed structure is evaluated in terms of sensitivity, specificity, accuracy and ROC. The results revealed that PNN was the best classifiers by achieving accuracy rates of 100 and 97.66 % in both training and testing phases, respectively. MLP was ranked as the second classifier and was capable of achieving 97.80 and 96.34 % classification accuracy for training and validation phases, respectively, using scaled conjugate gradient learning algorithm. However, RBF performed better than MLP in the training phase, and it has achieved the lowest accuracy in the validation phase.     

Decision-based neural networks with signal/image classificationapplications

Supervised learning networks based on a decision-based formulation are explored. More specifically, a decision-based neural network (DBNN) is proposed, which combines the perceptron-like learning rule and hierarchical nonlinear network structure. The decision-based mutual training can be applied to both static and temporal pattern recognition problems. For static pattern recognition, two hierarchical structures are proposed: hidden-node and subcluster structures. The relationships between DBNN's and other models (linear perceptron, piecewise-linear perceptron, LVQ, and PNN) are discussed. As to temporal DBNN's, model-based discriminant functions may be chosen to compensate possible temporal variations, such as waveform warping and alignments. Typical examples include DTW distance, prediction error, or likelihood functions. For classification applications, DBNN's are very effective in computation time and performance. This is confirmed by simulations conducted for several applications, including texture classification, OCR, and ECG analysis.     

Integration of independent component analysis and neural networks for ECG beat classification

In this paper, we propose a scheme to integrate independent component analysis (ICA) and neural networks for electrocardiogram (ECG) beat classification. The ICA is used to decompose ECG signals into weighted sum of basic components that are statistically mutual independent. The projections on these components, together with the RR interval, then constitute a feature vector for the following classifier. Two neural networks, including a probabilistic neural network (PNN) and a back-propagation neural network (BPNN), are employed as classifiers. ECG samples attributing to eight different beat types were sampled from the MIT-BIH arrhythmia database for experiments. The results show high classification accuracy of over 98% with either of the two classifiers. Between them, the PNN shows a slightly better performance than BPNN in terms of accuracy and robustness to the number of ICA-bases. The impressive results prove that the integration of independent component analysis and neural networks, especially PNN, is a promising scheme for the computer-aided diagnosis of heart diseases based on ECG.