脉频调制神经网络VLSI的设计及应用

本文提出了一种用于故障诊断识别的改进脉冲频率调制(PFM)VLSI神经网络电路,改进了传统的基于软件的机械故障诊断模式,发挥了神经网络超大规模集成电路(VLSI)的优势.利用单层感知器网络、场效应管电路实现了一种新的数字模拟混合突触乘法/加法器电路,而且该神经网络电路的突触权值不需要学习调整,降低了电路的复杂性.以此电路为基础,设计了进行主轴承噪声故障诊断的神经网络故障识别系统.将含有故障信息的原始噪声信号,经过前置信号处理分析、故障特征值提取和神经网络运算,得出VLSI电路输出端电容的电压——代表待识别信号与模板故障信号的“欧氏距离”,进而判断出故障的类别.经过仿真测试,基于硬件的诊断系统的识别性能接近于基于软件的系统.     

模拟神经网络VLSI脉冲流技术在故障诊断中的应用分析

介绍了模拟神经网络VLSI脉冲流技术实现神经网络模式识别硬件电路的方法，并且直接将故障分类。提出利用包含有故障信息的原始模拟噪声信号，经过前置信号处理和神经网络运算，得出VLSI电路输出端电容的电压值－代表待识别信号与模板故障信号的“欧氏距离”，以实现噪声故障信号的实时硬件在线识别。     

基于Temporal rule的忆阻神经网络电路

忆阻器是一种动态特性的电阻,其阻值可以根据外场的变化而变化,并且在外场撤掉后能够保持原来的阻值,具有类似于生物神经突触连接强度的特性,可以用来存储突触权值。在此基础上,为了实现基于Temporal rule对IRIS数据集识别学习的功能,建立了以桥式忆阻器为突触的神经网络SPICE仿真电路。采用单个脉冲的编码方式,脉冲的时刻代表着数据信息,该神经网络电路由48个脉冲输入端口、144个突触、3个输出端口组成。基于Temporal rule学习规则对突触的权值修改,通过仿真该神经网络电路对IRIS数据集的分类正确率最高能达到93.33%,表明了此神经系统结构设计在类脑脉冲神经网络中的可用性。     

基于小波神经网络的模拟电路故障诊断技术

文章提出了一种基于小波神经网络的模拟电路故障诊断方法:通过分析被测电路的冲激响应来识别电路中的故障元件,利用小波理论中的多分辨率分析的方法提取出相应信号中的故障特征,组成特征向量后输入神经网络进行训练,实现故障诊断;该方法减少了神经网络的输入、简化了其结构、并缩短了训练和处理时间,文中分别用小波神经网络和传统的BP神经网络对实例电路进行故障诊断,仿真结果发现:小波神经网络相比BP网络方法收敛速度更快,诊断率更高。     

基于小波包Tsallis熵和RVM的模拟电路故障诊断

针对模拟电路故障难以识别等问题,提出一种基于小波包Tallis熵和多分类相关向量机(Rele-vance Vector Machine,RVM)的模拟电路故障诊断方法.该方法采用脉冲信号仿真模拟电路,应用小波包变换对采集到的故障响应信号进行分解,通过提取不同频带内的Tsallis熵作为故障特征值,利用相关向量机对各种状态下的特征向量进行分类决策,实现模拟电路的故障定位.实验结果表明,提出的故障诊断方法相较于现有的故障诊断方法能较好地提取故障特征,极大地提高模拟电路故障诊断的效率.     

基于S变换和小波神经网络的容差模拟电路故障诊断

提出了一种结合S变换和小波神经网络的容差模拟电路故障诊断新方法;该方法通过对被测电路的冲激响应进行S变换,提取信号的时频信息做为特征量,并将所提取的特征量做为小波神经网络的输入进行训练并分类;仿真实验结果表明该方法诊断速度快且故障定位准确率高,在噪声影响、故障类型的特征向量重叠率高以及可测节点不足的情况下,具有良好的故障识别效果。     

基于小波变换多分辨率特征提取的模拟电路故障诊断方法研究

提出一种基于小波变换多分辨率特征提取的模拟电路故障诊断的方法。该方法先对采样后的故障信号进行小波分解,提取各频段系数作为特征向量输入到神经网络进行训练。通过带通滤波器电路诊断的实例,阐述该方法的具体实现,验证该方法可以有效地简化神经网络结构和减少它的训练时间,快速高效地进行模拟电路故障的诊断和定位。     

基于BP_Adaboost神经网络的船舶桨叶故障预警模型

为了提高船舶桨叶故障识别率,构建了一种基于BP_Adaboost神经网络的船舶桨叶故障预警模型。该模型首先采用数字水听器采集二进制船舶桨叶静水噪声信号,并利用MATLAB编程将二进制信号转换成WAV音频信号,通过梅尔频率倒谱系数法(Mel-Frequency Cepstral Coefficient,MFCC)提取特征值,得到36维桨叶静水噪声信号,最后运用BP_Adaboost神经网络进行分类识别预警。实验结果表明,基于BP_Adaboost神经网络的船舶桨叶故障预警模型能够高效分类预警船舶桨叶故障,与BP神经网络识别率对比,分类识别预警率高达96%。     

基于Park变换的三电平逆变器开路故障诊断

针对现有二极管钳位式(NPC)三电平逆变器开路故障诊断方法存在计算量大、准确率受噪声和负载等影响的问题,提出了一种基于Park变换的三电平逆变器开路故障诊断方法。对三电平逆变器三相输出电流进行Park变换,计算平均电流Park矢量;利用滑动窗口取得单周期电流信号,根据逆变器电路结构分析IGBT故障时输出电流变化;采用迭代法确定平均电流Park矢量模值的阈值,结合相角和模值进行三电平逆变器功率管13种开路故障的识别和定位。仿真结果表明,该方法故障诊断准确率达到了98.31%。与传统的开路故障诊断方法相比,该方法不需要对13种开路故障数据进行学习和训练,大大减少了计算量,提高了故障诊断效率和准确率。     

一种基于小波分析和神经网络的模拟电路故障诊断的方法研究

提出了一种基于小波分析和神经网络的电路故障诊断方法.首先用PSPICE(Simulation Program with Integrated CircuitEmphasis,即集成电路编程仿真技术)电路仿真软件对电路进行仿真;然后对电路的输出节点电压信号进行小波分解,提取各频段的能量作为故障样本;最后利用神经网络的并行处理结构和非线性映射能力,实现故障诊断.仿真实验结果表明该方法对容差模拟电路故障定位具有较高的准确率,为模拟电路故障诊断技术开辟了一条道路,为模拟电路故障诊断技术开辟了一条道路.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。