基于李雅普诺夫函数的BP神经网络算法的收敛性分析

针对前馈神经网络应时变输入的自学习机制，采用李雅普诺夫函数来分析权值的收敛性，从而揭示BP神经网络算法朝最小误差方向调整权值的内在因素，并在分析单参数BP算法收敛性基础上，提出单参数变调整法则的离散型BP神经网络算法．     

权值初始化与激励函数调整相结合的学习算法

提出了一种基于独立元分析(ICA)方法的权值初始化方法和动态调整S型激励函数的斜率相结合的神经网络学习算法。该方法利用ICA从输入数据中提取显著的特征信息来初始化输入层到隐含层权值。而且通过使神经网络的输出位于激励函数的活动区域,对隐含层到输出层的权值进行初始化。在学习过程中,再对每个隐单元和输出单元的激励函数的斜率进行自动调整。最后通过计算机仿真实际的基准问题,验证了论文提出的方法的有效性。实验结果表明,所提出的方法能有效地加快多层前向神经网络的训练过程。     

双向权值调整的前向神经网络学习算法

提出一种新的前向神经网络的学习算法,该算法在正向和反向阶段均可以对不同的层间的权值进行必要的调整，在正向阶段按最小范数二乘解原则确定连接隐层与输出层的权值，反向阶段则按误差梯度下降原则调整通连接输入层与隐层间的权值，具有很快的学习能力和收敛速度，并且能在一定的程度上保证所训练神经网络的泛化能力，实验结果初步验证了新算法的性能。     

气动肌肉关节的无模型自适应CMAC迟滞补偿控制

为补偿迟滞性对气动肌肉关节轨迹跟踪控制精度的破坏,首先建立了关节模型;推导得到迟滞力方程,测试分析了关节迟滞性;而后设计了无模型自适应CMAC神经网络迟滞补偿算法,该算法采用了充、放气双重结构;采用梯度下降法实时反馈调整充、放气过程的网络权值;采用4阶傅里叶拟合函数对网络权值降噪;基于高斯函数和邻域误差,设计误差可信度评估函数来调节学习率,抑制干扰对神经网络的影响;而后用三角波轨迹跟踪控制对神经网络进行了学习训练;最后将训练好的神经网络用于突发干扰下的正弦波轨迹跟踪控制.实验结果表明,该算法能自适应非线性曲线跟踪控制中的迟滞变化,有效抑制突发干扰,提高控制精度.     

一种结构自适应的径向基函数神经网络

提出了一种新的结构自适应的径向基函数(RBF)神经网络模型。在该模型中,自组织映射(SOM)神经网络作为聚类网络,采用无监督学习算法对输入样本进行自组织分类,并将分类中心及其对应的权值向量传递给RBF神经网络,分别作为径向基函数的中心和相应的权值向量;RBF神经网络作为基础网络,采用高斯函数实现输入层到隐层的非线性映射,输出层则采用有监督学习算法训练网络的权值,从而实现输入层到输出层的非线性映射。通过对字母数据集进行仿真,表明该网络具有较好的性能。     

一种结构自适应径向基函数神经网络

提出了一种新的结构自适应的径向基函数(RBF)神经网络模型。在该网络中,自组织映射(SOM)神经网络作为聚类网络,采用无监督学习算法对输入样本进行自组织分类,并将分类中心及其对应的权值向量传递给RBF神经网络,作为径向基函数的中心和相应的权值向量;RBF神经网络作为基础网络,采用高斯函数实现输入层到隐层的非线性映射,输出层则采用有监督学习算法训练网络的权值,从而实现输入层到输出层的非线性映射。通过对字母数据集进行仿真,表明该网络具有较好的性能。     

BP算法收敛性分析及改进

在标准BP神经网络的训练中,将误差函数作为权值调整的依据,使用固定学习率计算权值,这样的结果往往使网络的学习速度过慢甚至无法收敛。对此,从网络收敛的稳定性和速度的角度出发,分析了误差函数和权值修改函数,对算法中学习率的作用进行了具体的讨论,提出了一种根据误差变化对学习率进行动态调整的方法。该方法简单实用,能有效防止网络训练时出现发散,提高网络的收敛速度和稳定性。     

一种FCMAC及在Wiener模型辨识中的应用研究

本文将模糊算法和小脑模型神经网络有机地结合在一起，提出了一种单输入单输出(S ISO)的模糊小脑模型神经网络(FCMAC)．它在对输入进行分级量化的同时进行模糊量化，利 用Takagi Sugeno模糊算法进行推理，并将模糊算法引入CMAC的权值训练，具有输入量化级 数少、函数逼近精度高等特点．这种FCMAC用于Wiener模型辨识具有结构确定、计算量小、 训练速度快、辩识效果好等特点．     

基于可拓聚类的极限学习机神经网络

针对极限学习机(ELM)算法随机选择输入层权值的问题,借鉴第2类型可拓神经网络(ENN-2)聚类的思想,提出了一种基于可拓聚类的ELM(EC-ELM)神经网络。该神经网络是以隐含层神经元的径向基中心向量作为输入层权值,采用可拓聚类算法动态调整隐含层节点数目和径向基中心,并根据所确定的输入层权值,利用Moore-Penrose广义逆快速完成输出层权值的求解。同时,对标准的Friedman#1回归数据集和Wine分类数据集进行测试,结果表明,EC-ELM提供了一种简便的神经网络结构和参数学习方法,并且比基于可拓理论的径向基函数(ERBF)、ELM神经网络具有更高的建模精度和更快的学习速度,为复杂过程的建模提供了新思路。     

一种部分输入自调整神经网络及其在非线性数据重构中的应用

实际工业过程大部分是非线性过程,其遗失数据的重构问题不能采用现有的线性数据重构方法来解决.本文提出一种部分输入自调整神经网络,以待求的重构变量作为要调整的网络输入.与传统网络不同的是,该网络的权值和阚值先由另外的神经网络训练求得,通过神经网络后向传递算法只需对网络的部分输入值进行训练,这样将非线性数据重构问题转化为部分输入神经网络的训练问题.仿真结果验证本文方法的有效性.     

A kind of BP neural network algorithm based on grey interval

In order to improve the learning ability of a forward neural network, in this article, we incorporate the feedback back-propagation (FBBP) and grey system theory to consider the learning and training of a neural network new perspective. By reducing the input grey degree we optimise the input of the neural network to make it more rational for learning and training of neural networks. Simulation results verified the efficiency of the proposed algorithm by comparing its performance with that of FBBP and classic back-propagation (BP). The results showed that the proposed algorithm has the characteristics of fast training and strong ability of generalisation and it is an effective learning method.     

量子门线路神经网络及其改进学习算法研究

量子门线路神经网络（QGCNN）是一种直接利用量子理论设计神经网络拓扑结构或训练算法的量子神经网络模型。动量更新是在神经网络的权值更新中加入动量,在改变权值向量的同时提供一个特定的惯量,从而避免权值向量在网络训练过程中持续振荡。在基本的量子门线路神经网络的学习算法中引入动量更新原理,提出了一种具有动量更新的量子门线路网络算法（QGCMA）。研究表明,QGCMA保持了网络100%的收敛率,同时,相对于基本算法,在具有相同学习速率的情况下,提高了网络的收敛速度。     

基于状态延迟动态递归神经网络的机器人动态自适应跟踪辨识

对一种在Elman动态递归网络基础上发展而来的复合输入动态递归网络(CIDRNN)作 了改进,提出一种新的动态递归神经网络结构,称为状态延迟动态递归神经网络(State Delay Input Dynamical Recurrent Neural Network).具有这种新的拓扑结构和学习规则的动态递归网 络,不仅明确了各权值矩阵的意义,而且使权值的训练过程更为简洁,意义更为明确.仿真实验 表明,这种结构的网络由于增加了网络输入输出的前一步信息,提高了收敛速度,增强了实时 控制的可能性.然后将该网络用于机器人未知非线性动力学的辨识中,使用辨识实际输出与机理 模型输出之间的偏差,来识别机理模型或简化模型所丢失的信息,既利用了机器人现有的建模 方法,又可以减小网络运算量,提高辨识速度.仿真结果表明了这种改进的有效性.     

A fast multilayer neural-network training algorithm based on thelayer-by-layer optimizing procedures

A faster new learning algorithm to adjust the weights of the multilayer feedforward neural network is proposed. In this new algorithm, the weight matrix (W(2)) of the output layer and the output vector (Y) of the previous layer are treated as two variable sets. An optimal solution pair (W(2)*,Y(P)*) is found to minimize the sum-square-error of the patterns input. Y(P)* is then used as the desired output of the previous layer. The optimal weight matrix and layer output vector of the hidden layers in the network is found with the same method as that used for the output layer. In addition, the dynamic forgetting factors method makes the proposed new algorithm even more powerful in dynamic system identification. Computer simulation shows that the new algorithm outmatches other learning algorithms both in converging speed and in computation time required.     

一种新型的动态递归神经网络及其全自动设计算法

本文基于非线形自回归滑动平均模型NARMA模 型和前馈神经网络建模的思想,提出一种输入层与输出层神经元递归的动态递归神经网络; 基于进化计算中遗传算法和进化策略与自寻优BP算法的不同结合方式,提出两种动态递归神 经网络全自动高效设计算法,实现了网络结构、权重和自反馈增益同时优化学习,实例应用 表明所提网络结构及其设计算法的有效性．     

Neural-network predictive control for nonlinear dynamic systems with time-delay

A new recurrent neural-network predictive feedback control structure for a class of uncertain nonlinear dynamic time-delay systems in canonical form is developed and analyzed. The dynamic system has constant input and feedback time delays due to a communications channel. The proposed control structure consists of a linearized subsystem local to the controlled plant and a remote predictive controller located at the master command station. In the local linearized subsystem, a recurrent neural network with on-line weight tuning algorithm is employed to approximate the dynamics of the time-delay-free nonlinear plant. No linearity in the unknown parameters is required. No preliminary off-line weight learning is needed. The remote controller is a modified Smith predictor that provides prediction and maintains the desired tracking performance; an extra robustifying term is needed to guarantee stability. Rigorous stability proofs are given using Lyapunov analysis. The result is an adaptive neural net compensation scheme for unknown nonlinear systems with time delays. A simulation example is provided to demonstrate the effectiveness of the proposed control strategy.     

一种新的双权值前向神经网络学习算法

提出了一种新的基于遗传算法和误差反向传播的双权值神经网络学习算法,同时确定核心权值、方向权值以及幂参数、学习率等参数,通过适当地调节这些参数,可以实现尽可能多种不同超曲面的特性以及起到加快收敛的效果。并通过对实际的模式分类问题的仿真,将文中的方法与带动量项BP算法、CSFN等算法进行了比较,验证了其有效性。实验结果表明所提出的方法具有分类准确率高、收敛速度快的优点。     

A new simple /spl infin/OH neuron model as a biologically plausible principal component analyzer

A new approach to unsupervised learning in a single-layer neural network is discussed. An algorithm for unsupervised learning based upon the Hebbian learning rule is presented. A simple neuron model is analyzed. A dynamic neural model, which contains both feed-forward and feedback connections between the input and the output, has been adopted. The, proposed learning algorithm could be more correctly named self-supervised rather than unsupervised. The solution proposed here is a modified Hebbian rule, in which the modification of the synaptic strength is proportional not to pre- and postsynaptic activity, but instead to the presynaptic and averaged value of postsynaptic activity. It is shown that the model neuron tends to extract the principal component from a stationary input vector sequence. Usually accepted additional decaying terms for the stabilization of the original Hebbian rule are avoided. Implementation of the basic Hebbian scheme would not lead to unrealistic growth of the synaptic strengths, thanks to the adopted network structure.     

Counter-Propagation Neural Networks for Molecular Sequence Classification: Supervised LVQ and Dynamic Node Allocation

A modified counter-propagation (CP) algorithm with supervised learning vector quantizer (LVQ) and dynamic node allocation has been developed for rapid classification of molecular sequences. The molecular sequences were encoded into neural input vectors using an n–gram hashing method for word extraction and a singular value decomposition (SVD) method for vector compression. The neural networks used were three-layered, forward-only CP networks that performed nearest neighbor classification. Several factors affecting the CP performance were evaluated, including weight initialization, Kohonen layer dimensioning, winner selection and weight update mechanisms. The performance of the modified CP network was compared with the back-propagation (BP) neural network and the k–nearest neighbor method. The major advantages of the CP network are its training and classification speed and its capability to extract statistical properties of the input data. The combined BP and CP networks can classify nucleic acid or protein sequences with a close to 100% accuracy at a rate of about one order of magnitude faster than other currently available methods.     

Uncertain data stream algorithm based on clustering RBF neural network

In this paper, the existing algorithms for modeling uncertain data streams based on radial basis function neural networks have problems of low accuracy, weak stability and slow speed. A new clustering method for uncertain data streams is proposed. Radial basis function neural network of the algorithm. The algorithm firstly models the uncertain data stream, then combines the fuzzy theory and the neural network principle to obtain the radial basis function neural network, and then obtains the radial basis function neural network through the clustering algorithm of the regular tetrahedral uncertain vector. The central weight and width weights ultimately result in hidden layer output and output layer output results. The experimental results show that the proposed algorithm is an effective algorithm for modeling uncertain data streams using clustering radial basis function neural networks. It has higher precision, stability and speed than similar algorithms.