基于模糊神经网络的板级电路故障诊断研究

板级电路故障诊断过程复杂，故障征兆和故障原因之间存在着许多不确定因素，建立精确的故障诊断系统存在着许多困难。针对这种情况，本文提出了基于模糊神经网络，利用模糊逻辑和神经网络相结合建立故障系统的方法，并以某电路板为研究对象对该方法作了验证。结果表明，该方法是可行的和有效的。     

固体火箭发动机故障诊断的神经网络方法研究

固体火箭发动机地面试验系统的故障诊断过程复杂,故障征兆和故障原因之间存在着许多不确定因素,精确定位故障存在许多困难.传统的神经网络方法和模糊推理方法为解决这一类故障诊断问题提出了一些算法,然而难以提高不确定故障诊断的性能.针对这种情况,提出了一种基于模糊神经网络的故障诊断方法.该算法同时具备了模糊理论的处理不确定、不准确信息的推理能力和神经网络的自学习能力.将这种方法应用到某固体火箭发动机地面试验系统的故障诊断,仿真结果表明,该算法有效,较好地解决了固体火箭发动机地面试验系统的不确定故障诊断问题.     

基于故障树的模糊神经网络的应用研究

过程系统比较复杂,故障征兆和故障原因之间存在许多不确定因素。对这类系统进行故障诊断存在许多困难。针对这类系统本文提出了基于故障树信息,利用模糊逻辑与神经网络相结合建立故障诊断系统的方法。并以某高温硝酸冷却系统为研究对象介绍了具体的实现过程,对该方法作了验证。结果表明,该方法是可行和有效的。     

基于故障树的模糊神经网络的应用研究

过程系统比较复杂,故障征兆和故障原因之间存在许多不确定因素,对这类系统进行故障诊断存在许多困难,针对这类系统本文提出了基于故障树信息,利用模糊逻辑与神经网络结合建立故障诊断系统的方法,并以某高温硝酸冷却系统为研究对象介绍了具体的实现过程,对该方法作了验证,结果表明,该方法是可行和有效的。     

神经网络和模糊系统在故障诊断中的应用

本文提出了一种神经网络和模糊系统相结合的分级式故障诊断方法。神经网络通过对部分测量数据的处理，实现系统的回路级故障诊断，输出各回路故障出现的可信度。模糊系统通过对神经网络得到的初步诊断结果和其他测量值的处理，实现系统的元件级故障诊断，并对最终诊断结果作出解释。该方法融合了神经网络自适应学习能力强和模糊系统知识表达明确的优点，简化了神经网络学习数据获取及模糊推理规则建立的过程。通过对热硝酸冷却系统故障诊断的仿真，证明了该故障诊断方法的有效性。     

基于模糊自组织映射神经网络的故障诊断方法

在研究Kohonen自组织映射网络理论的基础上运用模糊理论方法建立了刹车系统模糊故障诊断模型。该模型只需选择足够的具有代表性的故障样本训练神经网络，将代表故障的信息输入给训练好的神经网络，根据神经网络的输出结果，就可以判断发生故障的类型。该模型除能识别已训练过的故障，还能识别未训练过的故障，并且聚类能力强、速度快，因此很符合复杂系统的故障诊断。     

模糊神经网络及其在控制系统故障诊断中的应用

针对控制系统中模拟电路故障诊断时的不确定性问题,提出了将模糊理论和神经网络相结合的方法;首先利用模糊理论描述不确定性信息,然后利用人工神经网络完成不确定性推理,最后利用模糊理论对推理结果进行解释和决策,从而得出故障诊断结论;结合某型船舶主机遥控系统中延时电路板的故障诊断问题,阐述了将该方法应用于实际控制系统的故障诊断过程;结果表明,该方法能够较好地处理模拟电路故障诊断过程中的不确定性问题,有效地提高故障模式的识别能力,将故障准确地定位到元器件.     

整流电路智能故障诊断系统

以三相桥式全控整流电路为研究对象,对其各种故障模式进行分析和归类,提出采用小波分析和神经网络诊断电力电子装置故障的方法,建立神经网络的输出和故障元之间的对应关系,设计了基于DSP的三相桥式整流电路的在线故障诊断系统。测试结果表明,该系统具有良好的故障诊断效果,具有一定的实用价值。     

模糊神经网络在模拟电路故障诊断中的应用

将模糊理论和神经网络结合起来用于模拟电路的故障诊断是一种有效的方法.首先测得模拟电路在故障状态和正常状态时各测试节点的电压值,并对其电压偏差值模糊化,从而求得不同故障状态下各测试节点的电压偏差值所对应的隶属度;其次,以各测试节点的隶属度和所对应的故障类型作为训练神经网络的样本,来建立从故障特征到故障类型的非线性函数;最后.将该方法用于视频放大电路的故障诊断.仿真结果验证了该方法的有效性.     

基于小波变换和神经网络的PWM逆变电路故障诊断

为了实现PWM逆变电路开路故障的诊断及定位,提出了基于小波变换和神经网络的开路故障诊断方法。该方法利用小波变换从输出电流中提取故障特征向量,并将故障特征向量输入建立的三层BP神经网络中进行训练,最后使用测试样本验证神经网络的故障诊断正确性。仿真结果表明,该方法能实现1只或2只功率器件的开路故障诊断及定位,故障诊断准确性高。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.