区间小波神经网络(I)-理论与实现

本文提出了前馈神经网络学习的一种新理论棗区间小波神经网络,不同于以往工作的是本工作的主要特点有:(1) 采用区间小波空间作为神经网络的学习基底空间,克服了以往神经网络基空间与被学习信号所属空间不匹配问题;(2) 由于采用区间小波理论,克服了原来被学习信号为适应神经网基空间而延拓所带来的不光滑性,使神经元数目得以节约,这在高维学习情形效果极为显著;(3) 神经单元所用活性函数不再为同一个函数.     

分类区间小波网络在目标识别中的应用

介绍一种区间小波的构造方法.并将区间小波与神经网络相结合,提出一种用于信号分类的分类区间小波网络,利用它解决小波网络的基底空间与被学习信号所属空间不匹配的问题.在分类区间小波网络模型中引入模拟退火策略,并采用自适应变学习系数训练网络.实验结果表明,将分类区间小波网络应用于雷达目标识别,可以减少神经元数目,提高网络收敛速度,并能较好解决高维学习的"维数灾难"问题,获得较好的分类效果.     

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.     

一种改进的RBF网络结构及其参数的设计方法

针对神经网络在学习之后,模糊系统的原始结构被改变,或削弱了规则可解释性这一模糊系统突出特点的问题,给出了一种提取模糊If-then规则的径向基函数(RBF)神经网络结构。该神经网络结构具有能够同时清晰表达模糊控制系统输入空间划分和模糊规则可解释性的特点,克服了以往用神经网络提取模糊规则不能直观体现模糊语言规则可解释性的不足,并详细地讨论了此网络结构参数的设计方法。     

小波神经网络在NGN流量预测中的应用

基于下一代网络NGN（Next Generation Network）的运行环境，该文提出了一个的基于小波神经网络的IP流量预测方法。在神经网络预测模型中，神经网络中的转移函数使用小波函数来替代，从而建立小波基神经网络；同时，通过使用小波多分辨率方法将原始流量信号分解成不同频率成分的分量信号，然后使用分量信号作为训练样本训练小波基神经网络。通过前述方法建立NGN流量预测模型，并根据实际流量数据预测一天的流量。实验结果表明本方法相较未采用小波的神经网络预测方法，能显著提高流量预测精度。     

模拟电路故障特征提取的小波基选取方法研究

小波技术在高维故障特征数据的压缩及敏感信号提取已被广泛应用,但小波基的选取没有一个统一的标准;通过实际采样信号数据的小波分解、特征向量计算、波动性函数比较等技术对小波基函数的选取进行了研究;最后通过综合小波分析、神经网络等技术的模拟电路故障诊断系统的诊断实例验证了所提选取方法的有效性;使用9种常用小波基函数,分别对采样信号进行分解并计算波动性函数,并在模拟电路故障诊断系统进行验证;小波基函数bior2.2的波动较小且与诊断结果一致。     

区间小波神经网络(ⅠⅠ)--性质与模拟

证明了区间小波神经网络具有一致及L2逼近性质,且为相容的函数估计子,其学习收敛速度在d维情形不随d增大而减慢,本质上克服了神经网络高维学习的"维数灾难"问题,模拟实例验证了理论的正确性.     

基于小波神经网络的通用多变量非线性系统辨识算法和应用

在分析小波函数对L2(R)空间的逼近原理的基础上,给出了仅使用尺度函数的神经网络模型和网络学习方法,使得用于逼近低通系统的小波基函数大大减少,并给出逼近的理论依据.提出的小波神经网络模型的学习为线性LS参数估计问题,具有通用性和易用性,并具有线性系统中线性LS参数估计的优良性质,保证了在训练数据受噪声污染时的网络模型的推广能力.理论分析、仿真实验和实际应用结果都说明该辨识方法具有好的辨识精度和推广能力.     

区间小波神经网络(II)——性质与模拟

证明了区间小波神经网络具有一致及Ｌ２逼近性质，且为相容的函数估计子，其学习收敛速度在ｄ维情形不随ｄ增大而减慢，本质上克服了神经网络高维学习的“维数灾难”问题，模拟实例验证了理论的正确性．     

区间小波神经网络(ⅠⅠ)——性质与模拟

证明了区间小波神经网络具有一致及L²逼近性质,且为相容的函数估计子,其学习收敛速度在d维情形不随d增大而减慢,本质上克服了神经网络高维学习的“维数灾难”问题,模拟实例验证了理论的正确性. 关 键 词　神经网络,小波,多尺度分析,收敛.     

Artificial wavelet neural network and its application in neuro-fuzzy models

In the proposed work, two types of artificial neural networks are proposed by using well-known advantages and valuable features of wavelets and sigmoidal activation functions. Two neurons are derived by adding and multiplying the outputs of the wavelet and the sigmoidal activation functions. These neurons in a feed-forward single hidden layer network result summation wavelet neural network (SWNN) and multiplication wavelet neural network (MWNN). An algorithm is introduced for structure determination of the proposed networks. Approximation properties of SWNN and MWNN have been evaluated with different wavelet functions. The above networks in the consequent part of the neuro-fuzzy model result summation wavelet neuro-fuzzy (SWNF) and multiplication wavelet neuro-fuzzy (MWNF) models. Different types of wavelet function are tested with the proposed networks and fuzzy models on four different dynamical examples. Convergence of the learning process is also guaranteed by adaptive learning rate and performing stability analysis using Lyapunov function.     

多聚合过程神经元网络及其学习算法研究

针对系统输入为多元过程函数以及多维过程信号的信息处理问题,提出了多聚合过程神经元和多聚合过程神经元网络模型.多聚合过程神经元的输入和连接权均可以是多元过程函数,其聚合运算包括对多个输入函数的空间加权聚集和对多维过程效应的累积,可同时反映多个多元过程输入信号在多维空间上的共同作用影响以及过程效应的累积结果.多聚合过程神经元网络是由多聚合过程神经元和其它类型的神经元按照一定的结构关系组成的网络模型,按照输出是否为多元过程函数建立了前馈多聚合过程神经元网络的一般模型和输入输出均为过程函数的多聚合过程神经元网络模型,具有对多元过程信号输入输出关系的直接映射和建模能力.文中给出了一种基于多元函数基展开的梯度下降与数值计算相结合的学习算法,仿真实验结果表明了模型和算法对多元过程信号分类和多维动态过程模拟问题的适应性.     

The use of artificial neural networks for classification of signal sources in cognitive radio systems

In the paper, methods of classification of signal sources in cognitive radio systems that are based on artificial neural networks are discussed. A novel method for improving noise immunity of RBF networks is suggested. It is based on introducing an additional self-organizing layer of neurons, which ensures automatic selection of variances of basis functions and a significant reduction of the network dimension. It is shown that the use of auto-associative networks in the problem of the classification of sources of signals makes it possible to minimize the feature space without significant deterioration of its separation properties.     

泛函网络神经元构造理论与方法

泛函网络是近年提出的一种对神经网络的有效推广.与神经网络不同,它处理的是一般的泛函模型,它在各个神经元之间的连接没有权值,并且神经元函数不固定的,往往是一给定的基函数的组合,泛函网络学习的目的就是求出神经元函数的精确表达式或近似表达式. 迄今关于泛函网络神经元基函数的存在性和选取方法缺乏理论依据.文中基于Banach空间中偏序理论,分析了泛函网络神经元基函数的存在性,给出了泛函网络神经元基函数选取方法,对于完善泛函网络的基础理论具有参考价值.     

基于函数正交基展开的过程神经网络学习算法

过程神经网络的输入和连接权均可为时变函数，过程神经元增加了一个对于时间的聚合算子，使网络同时具有时空二维信息处理能力．该文在考虑过程神经网络对时间聚合运算的复杂性的基础上，提出了一种基于函数正交基展开的学习算法．在网络输入函数空间中选择一组适当的函数正交基，将输入函数和网络权函数都表示为该组正交基的展开形式，利用基函数的正交性．简化过程神经元对时间的聚合运算．应用表明，算法简化了过程神经网络的计算复杂度，提高了网络学习效率和对实际问题求解的适应性．以旋转机械故障诊断问题和油藏开发过程采收率的模拟为例验证了算法的有效性．     

过程神经元网络及其在时变信息处理中的应用

针对时变信息处理和动态系统建模等类问题，建赴了输入输出均为时变函数的过程神经元网络和有理式过程神经元网络2种网络模型．在输入输出为时变函数的过程神经元网络中，过程神经元的时间累积算子取为对时间的积分或其他代数运算，它的时空聚合机制和激励能同时反映外部时变输入信号对输出结果的空间聚合作用和时间累积效应，可实现非线性系统输入、输出之间的复杂映射关系．在有理式过程神经元网络中，其基本信息处理单元为由2个成对偶出现的过程神经元组成，逻辑上分为分子和分母2部分，通过有理式整合后输出，可有效提高过程神经元网络对带有奇异值过程函数的柔韧逼近性和在奇异值点附近反应的灵敏性．分析了2种过程神经元网络模型的性质，给出了具体学习算法，并以油田开发过程模拟和旋转机械故障诊断问题为例，验证了这2种网络模型在时变信息处理中的有效件．     

Improved Complex-valued Radial Basis Function (ICRBF) neural networks on multiple crack identification

This paper introduces a new class of neural networks in complex space called Complex-valued Radial Basis Function (CRBF) neural networks and also an improved version of CRBF called Improved Complex-valued Radial Basis Function (ICRBF) neural networks. They are used for multiple crack identification in a cantilever beam in the frequency domain. The novelty of the paper is that, these complex-valued neural networks are first applied on inverse problems (damage identification) which come under the category of function approximation. The conventional CRBF network was used in the first stage of ICRBF network and in the second stage a reduced search space moving technique was employed for accurate crack identification. The effectiveness of proposed ICRBF neural network was studied first on a single crack identification problem and then applied to a more challenging problem of multiple crack identification in a cantilever beam with zero noise as well as 5% noise polluted signals. The results proved that, the proposed ICRBF and real-valued Improved RBF (IRBF) neural networks have identified the single and multiple cracks with less than 1% absolute mean percentage error as compared to conventional CRBF and RBF neural networks, mainly because of their second stage reduced search space moving technique. It appears that IRBF neural network is a good compromise considering all factors like accuracy, simplicity and computational effort.     

Rough sets for adapting wavelet neural networks as a new classifier system

Classification is an important theme in data mining. Rough sets and neural networks are two techniques applied to data mining problems. Wavelet neural networks have recently attracted great interest because of their advantages over conventional neural networks as they are universal approximations and achieve faster convergence. This paper presents a hybrid system to extract efficiently classification rules from decision table. The neurons of such hybrid network instantiate approximate reasoning knowledge gleaned from input data. The new model uses rough set theory to help in decreasing the computational effort needed for building the network structure by using what is called reduct algorithm and a rules set (knowledge) is generated from the decision table. By applying the wavelets, frequencies analysis, rough sets and dynamic scaling in connection with neural network, novel and reliable classifier architecture is obtained and its effectiveness is verified by the experiments comparing with traditional rough set and neural networks approaches.     

TWO-LAYER STABILIZATION OF CONTINUOUS NEURAL NETWORKS WITH FEEDBACKS

Methods of stabilization as applied to Hopfield-type continuous neural networks with a unique equilibrium point are considered. These methods permit the design of stable networks where the elements of the interconnection matrix and nonlinear activation functions of separate neurons vary with time. For stabilization with a variable interconnection matrix it is suggested that a new second layer of neurons be introduced to the initial single-layer network and some additional connections be added between the new and old layers. This approach gives us a system with a unique equilibrium point that is globally asymptotically stable, i.e. the entire space serves as the domain of attraction of this point, and the stability does not depend on the interconnection matrix of the system. In the case of the variable activation functions, some results from a recent investigation of the absolute stability problem for neural networks are presented, along with some recommendations.