固体氧化物燃料电池温度特性的T-S模糊建模

固体氧化物燃料电池（SOFC）工作温度对于其输出电特性的性能起着重要的作用。由于电池在电化学反应过程中,温度特性呈现强非线性等特性,采用常规机理建模后难以在该模型的基础上较好地管理温度特性。为此,设计了面向控制的改进型T-S模型的模糊建模方法来解决此难题。实验仿真结果表明该模糊模型能精确拟合温度动态响应的映射特性,为下一步控制算法的实现奠定了良好的基础。     

基于启发式动态规划的固体氧化物燃料电池优化控制研究

固体氧化物燃料电池(SOFC)系统是一个非线性系统,现存的建模方法和优化控制算法很难对其进行精确的建模及优化控制;针对此问题,采用基于数据的建模方法,对固体氧化物燃料电池系统进行BP神经网络建模,然后在此基础上,首次采用启发式动态规划(HDP)算法对固体氧化物燃料电池系统中的各种气体分压、输出电压以及温度进行优化控制;Matlab仿真结果表明,基于BP神经网络的HDP优化算法具有收敛速度快、鲁棒性强、控制精度高等优点,并使固体氧化物燃料电池系统在负载变化时很快稳定输出电压,实现了优化控制,减少能耗。     

基于LS-SVM的SOFC系统自适应逆控制

关于固体氧化物燃料电池(Solid Oxide Fuel Cell,SOFC)性能的优化问题,其中工作温度和电压是关键参数。针对固体氧化物燃料具有较强的非线性且常规成熟线性理论不适用的特点,提出了一种最小二乘支持向量机(LS-SVM)的自适应逆控制策略。首先建立了SOFC的机理模型,然后采用LS-SVM方法建立了SOFC系统的逆动力学模型。在获得逆动力学模型的基础上,设计了一种逆动力学递推最小二乘支持向量机的控制方法。在自适应逆控制下,逆模型通过RLS算法更新,控制器依据ε-滤波进行在线调整。SOFC系统辨识和仿真结果表明,改进方法的可信性,辨识出的逆动力模型具有较高的精度,所设计的控制器能获得较好的控制性能。仿真结果可以为SOFC的实用化和产业化提供一定的理论依据。     

安全操控下5 kW固体氧化物燃料电池电堆预测控制器设计

基于5 kW固体氧化物燃料电池(SOFC)电堆,考虑建模仿真—2温度层模型在模型精度与复杂度上做了更好的折中,可以更有效地应用于控制器设计.本文首先对2温度层模型在常用稳态工作点附近采用泰勒级数展开,获得其状态空间方程.然后考虑其安全操作特性,设计了两种带约束的预测控制器:即面向SOFC电堆的快速负载跟踪与燃料亏空控制...     

基于广义回归神经网络的SOFC电压模型研究靠

首先介绍并分析了固体氧化物燃料电池(SOFC)的工作原理和理论电压模型.然后,针对SOFC系统过于复杂,理论电压模型存在明显不足的特点,试图绕开SOFC的内部复杂性,利用广义回归神经网络(GRNN)对SOFC系统进行辨识建模.模型以电池工作温度为神经网络辨识模型的输入量,电池电压/电流密度为输出量,利用750组实验数据作为训练样本,建立了SOFC在不同工作温度下的电池电压/电流密度动态响应模型.仿真结果表明了该方法的有效性,所建模型精度也较高.     

基于人工神经网络的固体氧化物燃料电池性能 预测模型开发

固体氧化物燃料电池(Solid-Oxide Fuel Cell,SOFC)因其能量转换效率高而备受关注,但其相 关技术非常复杂,技术成熟度比质子交换膜燃料电池、直接甲醇燃料电池等其他类型的燃料电池低。 SOFC 的微观结构是影响其性能的因素之一,为加速 SOFC 的商业化应用,需要对其复杂微观结构进 行有效优化。同时,SOFC 性能测试实验耗时长、费用高,而高可靠性的 SOFC 计算机模型可用来缩 短 SOFC 微观结构优化时间和降低研发成本。该研究根据阳极支撑 SOFC 结构变化对应的性能实验 数据,开发了一种基于人工神经网络的、根据结构特性来预测其性能的 SOFC 计算机模型。实验过程 利用部分数据对该人工神经网络进行训练,并利用另一部分数据对其进行验证。结果显示,所开发的 SOFC 模型能够准确地根据微观结构的变化呈现其性能变化,适合用于 SOFC 微观结构的优化。     

基于神经模糊模型的CSTR系统预测控制

针对具有高度非线性特性的连续搅拌反应釜(CSTR)控制过程,研究了基于神经模糊模型的预测控制策略.利用神经模糊模型预测CSTR系统在一定预测时段的输出,基于进化规划(EP)的优化算法,使用神经模糊模型的预测输出来确定输入序列,实现对CSTR的PH值跟踪控制,仿真结果表明该方法可以获得满意的跟踪控制效果.     

管式SOFC数学模型及系统性能分析

固体氧化物燃料电池(SOFC)是一种高效低污染的新型能源。该文基于物质和能量守恒并耦合流体流动、热量产生和传递以及电化学知识建立了以天然气为燃料的管式固体氧化物燃料电池的数学模型,对模型进行求解,并分析系统参数(电流密度、工作压力、燃料的摩尔流量等)对系统性能(发电量、发电效率等)的影响。结果表明:SOFC系统的发电效率可以达到50.73%。通过增加单电池个数来减小电流密度可以增加系统发电量和发电效率,但是会增加系统投资;增大燃料电池的工作压力可以改善系统的性能;而增加燃料的摩尔流量(燃料利用率不变)会使系统的发电效率降低。     

基于模糊模型的时滞不确定系统的模糊H∞鲁棒反馈控制

讨论了一类具有状态和控制时滞的不确定非线性系统的模糊H∞状态反馈控制问题.采用具有时滞的不确定Takagi-Sugeno(T-S)模糊模型对非线性系统进行建模,提出了一套基于LMI的模糊鲁棒控制器的系统设计方法,给出了模糊H∞状态反馈控制器存在的充分条件,以保证闭环模糊系统渐近稳定并满足从干扰输入到控制输出的H∞范数界约束.示例仿真表明了该方法的有效性.     

基于改进RBF神经网络模型的SOFC性能预测方法

固体氧化物燃料电池(SOFC)测试存在费用高、实施困难以及耗时长等问题,因此,提出了一种基于径向基(radial basis function, RBF)神经网络的SOFC建模方法。首先采用数据驱动的方式利用RBF神经网络模型对电池中阳极、阴极、电解质厚度等微观结构对SOFC性能的影响进行分析,然后针对RBF神经网络模型参数选取困难、易陷入局部极值的问题,提出一种改进果蝇算法(improved fruit fly optimization algorithm, IFOA)对其进行优化,自动确定模型参数的同时确保其收敛于全局最优解。仿真结果表明,所提方法能够准确描述微观结构变化对SOFC性能的影响,相对于支撑向量机(support vector machine, SVM)模型能够获得更高的预测精度。     

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。