木材缺陷声发射信号的小波包分析处理

在简要介绍小波包分析的分解和重构算法基础上,通过木材声发射实验采集声发射信号;利用小波包分析技术对三种不同缺陷类型的木材试件的原始数据进行消噪预处理,然后对信号进行分解,并对分解的信号进行小波包重构;运用“小波包-能量”法提取木材声发射信号特征值,实现了木材缺陷状态和声发射信号特征向量之间的映射关系。结果表明：用小波包分析确定木材缺陷程度是一种有效的方法。     

基于Web和数据挖掘技术的智能教学系统研究

传统的智能网络教学系统在适应性和个性化方面存在严重缺陷.基于Web和数据挖掘技术构建了一个智能教学系统的模型,该模型采用人工神经网络、聚类分析等关键技术,获取学生对知识点的理解程度,并对学生学习特征分类,根据学生的不同特征和兴趣点,提供不同的教学策略和教学内容,更有利于实现系统的个性化教学.     

基于人工神经网络控制的节能空调器的MATLAB仿真

整个系统仿真过程主要针对主流智能变频空调的控制系统分析,使用人工神经网络对控制系统进行建模,并使用人工神经网络中常用的Hopfield网络与BP网络模型对控制系统模型进行Matlab仿真编程,得出并对比两种网络对系统的仿真结果,其仿真结果表明两种网络从不同角度较好地反映了系统模型的功能特点.着重分析了人工神经网络理论对智能家用节能空调的控制系统仿真.     

支持向量机超声缺陷识别法的研究

提出了一种基于支持向量机超声波在线检测缺陷识别方法.首先采用小波包分析来提取超声信号的特征信息,产生训练和测试样本;然后利用支持向量机分类方法对缺陷进行识别.实验结果表明,支持向量机能够快速、有效地识别缺陷,比人工神经网络具有更好的分类性能和推广能力,是一种有效的超声缺陷识别方法.     

焊缝缺陷图像分类识别的深度置信网络研究

由于工业生产中所获取的焊缝缺陷图像背景较为复杂,对其分类识别效率较低,因此提出了一个由三层受限玻尔兹曼机叠加组成的深度置信网络模型.该网络模型在对焊缝原始图像进行更为全面的信息抽取前提下,能够借助深度置信网络自下而上对输入信息进行学习与训练的特点,逐渐减少对焊缝缺陷信息的误判;借助网络最后一层后向传播算法的作用,可以在确保更高正确率的同时缩短收敛时间,有效提升识别效率;通过与传统的支持向量机和人工神经网络进行对比实验,结果表明深度置信网络能更为有效地避免过拟合的发生,对于焊缝缺陷的特征识别具有更为理想的精度.     

改进YOLOv7的木材表面缺陷检测算法

优质木材深受人们喜爱,但木材存在多种缺陷导致优质木材产量少,木材利用率低。运用深度学习的目标检测算法可以实现木材表面缺陷的快速稳定检测,以此提高木材的优质化和利用率。针对目前木材表面缺陷目标小、密集和复杂等特点导致检测精度较差的问题,提出了一种基于改进YOLOv7的木材表面缺陷检测模型YOLOv7-ESS。针对木材的裂缝缺陷存在极端长宽比例而影响检测效果的问题,嵌入注意力模块ECBAM,通过加强对极端长宽比例缺陷的注意力,提高模型的特征提取能力。针对在提取特征时木材表面小缺陷特征信息丢失严重的问题,引入浅层加权特征融合网络SFPN,以深层特征图作为输出,同时有效利用浅层特征信息,提高小缺陷的识别准确率。引入SIoU损失函数,提升模型收敛速度及模型精度。结果表明,YOLOv7-ESS模型平均检测精度为94.7%,较YOLOv7检测精度提高了11.2个百分点,满足木材生产加工时的缺陷检测要求。     

基于纹理提取和SVM技术的自动木材缺陷识别

要：支持向量机（SVM）是一种新的模式识别方法,有较好的泛化能力和推广能力。研究了基于纹理提取和支持向量机的自动木材表面缺陷的识别问题,借助LBP纹理特征提取技术实现对木材图像数据降维处理,并研究了木材表面不同类型缺陷的分布规律。利用支持向量机分类算法对木材表面有无缺陷进行了快速准确的自动识别,实现了木材表面缺陷的自动定位。多次交叉实验表明,SVM分类算法对木材表面缺陷具有较好的识别能力,识别率可达96％以上。     

Lagrange优化神经网络的原理及实现

人工神经网络是指模拟人脑神经系统的结构和功能,运用大量的处理部件,由人工方式建立起来的网络系统.近几年来,人工神经网络的研究工作十分活跃,取得了很大的进展,研究开发出了几十种神经网络的模型,出现了多种新型神经网络.阐述了Lagrange优化神经网络的原理和简单的电路实现,它克服了传统的基于罚函数的神经网络的缺陷,直接对不等式约束进行处理,降低了网络规模和复杂度,是一种新型的优化神经网络,并通过计算机仿真对其可行性进行了验证.     

基于定型映射和属性计算网络的港区道路监控模型

利用合理的道路控制策略,可以提高道路通行能力和车辆平均速度,改善港区交通状况.介绍定性映射、定性基准的学习及属性智能计算器网络等理论,利用定性映射和属性计算网络理论,提出一种基于属性计算网络的港区道路主线协调控制的交通流控制策略,构建在不同气象条件下的洋山港区道路交通限速控制方案的模型.     

基于小波与数学形态学的木材缺陷检测

木材缺陷检测是木材加工中的重要步骤,为了实现木材缺陷自动检测,提出了一种基于小波与数学形态学的缺陷检测方法。首先用多尺度小波对缺陷图像进行分解,滤除缺陷图像中的干扰信息,然后进行小波重构,在重构图像上进行形态学bottom-hat变换,结合阈值处理和区域生长检测出各种木材缺陷。实验表明,该方法具有高效准确的特点,能够满足木材加工过程缺陷检测的实际需求。     

基于ANN的动态系统状态方程辨识建模仿真

对系统辨识原理、基于神经网络（ANN）的动态系统辨识进行了分析,针对动态系统辨识模型描述的复杂性,为简化ANN辨识建模的输入／输出关系的表达,提高算法的简洁性,采用了状态方程辨识模型,并给出了基于ANN的动态系统状态方程辨识模型。为比较分析不同网络结构的辨识建模效果及网络模型泛化能力,针对三种不同网络结构方案进行了辨识建模仿真研究。仿真结果最示,基于ANN的动态系统状态方程模型的辨识建模是有效的,并且简单合理的网络结构方案,可提高网络辨识模型的泛化能力。     

Artificial neural network and wavelet neural network approaches for modelling of a solar air heater

This paper reports on a modelling study of new solar air heater (SAH) system by using artificial neural network (ANN) and wavelet neural network (WNN) models. In this study, a device for inserting an absorbing plate made of aluminium cans into the double-pass channel in a flat-plate SAH. A SAH system is a multi-variable system that is hard to model by conventional methods. As regards the ANN and WNN methods, it has a superior capability for generalization, and this capability is independent on the dimensionality of the input data’s. In this study, an ANN and WNN based methods were intended to adopt SAH system for efficient modelling. To evaluate prediction capabilities of different types of neural network models (ANN and WNN), their best architecture and effective training parameters should be found. The performance of the proposed methodology was evaluated by using several statistical validation parameters. Comparison between predicted and experimental results indicates that the proposed WNN model can be used for estimating the some parameters of SAHs with reasonable accuracy.     

基于ANN的非线性系统GPC算法及仿真研究

将神经网络（ANN）技术应用于常规GPC算法,设计了基于ANN的非线性系统GPC结构方案,并对其控制原理和控制算法进行研究,基于ANN高度非线性映射等特性,运用数字仿真方法,对所设计的控制结构方案进行仿真研究,仿真结果显示,基于ANN的非线性系统GPC结构方案合理可行,并取得了满意的控制效果．     

遗传神经网络在语音识别中的应用研究

针对语音识别的特点,对BP神经网络在语音识别技术中的应用进行了探索性研究,进而结合人工智能领域较为有效的方法——遗传(GA)算法,针对传统BP算法识别准确率高但训练速度慢的缺点,对BP网络进行改进,构建了一种基于遗传神经网络的语音识别算法(GABP),并建立相应的语音识别系统。仿真实验表明,该算法有效地缩短了识别时间,提高了网络训练速度和语音的识别率。     

遗传神经网络在语音识别中的应用研究

针对语音识别的特点,对BP神经网络在语音识别技术中的应用进行了探索性研究,进而结合人工智能领域较为有效的方法——遗传（GA）算法,针对传统BP算法识别准确率高但训练速度慢的缺点,对BP网络进行改进,构建了一种基于遗传神经网络的语音识别算法（GABP）,并建立相应的语音识别系统。仿真实验表明,该算法有效地缩短了识别时间,提高了网络训练速度和语音的识别率。     

基于ANN逆模型补偿的复合控制系统仿真

为对复杂非线性系统进行辨识建模和实施有效控制,分析了基于神经网络的非线性系统逆模型的辨识和控制原理,研究了基于神经网络的非线性系统逆模型补偿的复合控制方法。基于复合控制思想,时常规PID控制器＋前馈神经网络逆模型补偿的复合控制结构方案进行了仿真。仿真结果表明,基于神经网络的非线性系统逆模型补偿的复合控制结构方案是有效的、相对简单的网络结构,可提高逆模型的泛化能力和非线性系统的控制精度。     

人工神经网络在EPDM硫化胶性能预测中的应用

该文将人工神经网络方法应用于EPDM硫化胶的性能预测，用按回归通用旋转组合设计方法设计的EPDM硫化胶20次性能试验数据作为人工神经网络的样本数据，利用MATLAB 6．5软件包中的神经网络工具箱，构造BP神经网络，优选最佳的神经网络参数，通过训练后，用于预测EPDM硫化胶的氧指数、扯断强度和伸长率性能。结果表明，训练好的神经网络可准确地预测EPDM硫化胶的有关性能，基于MATLAB 6．5的人工神经网络是分析EPDM配方各组分对硫化胶性能影响的一种快捷、可靠的新方法。     

Nonlinear dynamic system identification using Chebyshev functionallink artificial neural networks

A computationally efficient artificial neural network (ANN) for the purpose of dynamic nonlinear system identification is proposed. The major drawback of feedforward neural networks, such as multilayer perceptrons (MLPs) trained with the backpropagation (BP) algorithm, is that they require a large amount of computation for learning. We propose a single-layer functional-link ANN (FLANN) in which the need for a hidden layer is eliminated by expanding the input pattern by Chebyshev polynomials. The novelty of this network is that it requires much less computation than that of a MLP. We have shown its effectiveness in the problem of nonlinear dynamic system identification. In the presence of additive Gaussian noise, the performance of the proposed network is found to be similar or superior to that of a MLP. A performance comparison in terms of computational complexity has also been carried out.     

Estimation of all-terminal network reliability using an artificial neural network

The exact calculation of all-terminal network reliability is an NP-hard problem, with computational effort growing exponentially with the number of nodes and links in the network. During optimal network design, a huge number of candidate topologies are typically examined with each requiring a network reliability calculation. Because of the impracticality of calculating all-terminal network reliability for networks of moderate to large size, Monte Carlo simulation methods to estimate network reliability and upper and lower bounds to bound reliability have been used as alternatives. This paper puts forth another alternative to the estimation of all-terminal network reliability — that of artificial neural network (ANN) predictive models. Neural networks are constructed, trained and validated using the network topologies, the link reliabilities, and a network reliability upperbound as inputs and the exact network reliability as the target. A hierarchical approach is used: a general neural network screens all network topologies for reliability followed by a specialized neural network for highly reliable network designs. Both networks with identical link reliability and networks with varying link reliability are studied. Results, using a grouped cross-validation approach, show that the ANN approach yields more precise estimates than the upperbound, especially in the worst cases. Using the reliability estimation methods of the ANN, the upperbound and backtracking, optimal network design by simulated annealing is considered. Results show that the ANN regularly produces superior network designs at a reasonable computational cost.Scope and purposeAn important application area of operations research is the design of structures, products or systems where both technical and business aspects must be considered. One expanding design domain is the design of computer or communications networks. While cost is a prime consideration, reliability is equally important. A common reliability measure is all-terminal reliability, the probability that all nodes (computers or terminals) on the network can communicate with all others. Exact calculation of all-terminal reliability is an NP-hard problem, precluding its use during optimal network topology design, where this calculation must be made thousands or millions of times. This paper presents a novel computationally practical method for estimating all-terminal network reliability. Is shown how a neural network can be used to estimate all-terminal network reliability by using the network topology, the link reliabilities and an upperbound on all-terminal network reliability as inputs. The neural network is trained and validated on a very minute fraction of possible network topologies, and once trained, it can be used without restriction during network design for a topology of a fixed number of nodes. The trained neural network is extremely fast computationally and can accommodate a variety of network design problems. The neural network approach, an upper bound approach and an exact backtracking calculation are compared for network design using simulated annealing for optimization and show that the neural network approach yields superior designs at manageable computational cost.     

RBFNN versus FFNN for daily river flow forecasting at Johor River,Malaysia

Streamflow forecasting can have a significant economic impact, as this can help in water resources management and in providing protection from water scarcities and possible flood damage. Artificial neural network (ANN) had been successfully used as a tool to model various nonlinear relations, and the method is appropriate for modeling the complex nature of hydrological systems. They are relatively fast and flexible and are able to extract the relation between the inputs and outputs of a process without knowledge of the underlying physics. In this study, two types of ANN, namely feed-forward back-propagation neural network (FFNN) and radial basis function neural network (RBFNN), have been examined. Those models were developed for daily streamflow forecasting at Johor River, Malaysia, for the period (1999–2008). Comprehensive comparison analyses were carried out to evaluate the performance of the proposed static neural networks. The results demonstrate that RBFNN model is superior to the FFNN forecasting model, and RBFNN can be successfully applied and provides high accuracy and reliability for daily streamflow forecasting.