基于模糊前馈解耦的变风量空调控制方法研究

变风量(VAV)空调系统具有多变量、多回路耦合、大滞后、强非线性特点;采用数学建模和仿真实验法,针对送风温度、送风管道静压、室内温度和室内二氧化碳浓度4个相互耦合的主要被控量,通过建立热量平衡和物质传输机理模型和传递函数矩阵,设计基于神经网络的前馈模糊解耦方法;所提出的方法既利用了数学模型可清晰描述被控量之间耦合关系的优点,又避免了传统解耦算法控制效果过于依赖建模精度等问题,仿真和实验结果表明系统获得了良好的控制性能。     

变风量空调系统的迭代学习控制研究

针对变风量（VAV）空调系统下位机设定点变动时,整个系统完全达到稳态时间过长,且各子系统易出现超调的问题,提出采用一种迭代学习控制（ILC）的设定值序列优化方法。以空调系统中变频风机—管道静压控制回路为实例,说明该方法的可行性。采用递推最小二乘法（RLS）建立该回路的动态模型,并给出了一种新的迭代学习期望轨迹,应用迭代学习PD控制律对其动态过程进行仿真分析,并将此算法用于空调实验平台验证其控制效果。结果表明,ILC可以改善空调子系统的动态特性,为VAV空调系统的全局稳态优化奠定了基础。     

基于广义预测控制的VAV空调系统风管静压控制特性研究

基于广义预测控制理论,建立了VAV空调系统风管静压的预测控制模型并进行了仿真。仿真结果表明,该算法控制效果优于传统PID,为VAV空调系统的应用与推广提供了新的控制方法,从而使系统性能更好,更加节能。     

MFAC和前馈补偿组合的VAV系统解耦控制仿真

在空调机风量优化控制的研究中,变风量(Variable Air Volume,VAV)系统存在多变量、耦合强烈、非线性及带有时延等特点.针对子系统耦合严重的现象,提出了无模型自适应控制(Model Free Adaptive Control,MFAC)和前馈补偿相结合方法,建立了两个空气处理机组成的耦合系统的数学模型,设计了MFAC控制器和前馈补偿解耦网络,对所建立的耦合系统进行了解耦控制.仿真结果表明:相对PID与前馈补偿组合解耦而言,无模型自适应控制配合前馈补偿的方法可以大幅减少调节时间,且超调量为0,具有很好的解耦效果,可以解决变风量系统的耦合问题.     

基于神经网络的两步预测自适应控制器及其应用

设计了基于神经元网络的两步预测自适应控制器.这种控制方法在线运算量较少,并且能很好地控制复杂的非线性系统.仿真结果验证了这种方法的有效性.     

解析解耦设计在变风量空调系统中的应用

研究空调优化控制问题,变风量空调(VAV)具有多变量、强耦合和非线性系统.变量之间的耦合会直接影响空调系统的性能指标和稳定性.针对变风量空调系统进行建模,模型为三输入三输出的传递函数矩阵.在内模控制系统结构基础上,运用解耦控制的解析设计方法来设计解耦控制器.解耦设计方法可以达到标称系统变量间完全解耦,并且参数可以在线调整,使输出能够紧密跟随系统的动态变化.仿真结果表明,解耦控制器的设计提高了性能,应用效果较好.     

VAV空调系统的变静压控制和研究方法

在阐述了变风量空调系统变静压控制的基本原理的基础上,介绍了目前国外对变风量系统风机和送风静压控制方法的研究状况,对几种常用的变静压算法进行了综述,并提出了变静压控制策略的研究方法。     

非线性系统的多神经网络自学习控制

本文提出了一种未知非线性动力学系统的多网络自学习控制方法。通过对系统的神经元网络辨识器和神经元网络控制器的有机结合，发展了基于逆动力学辨识器的控制网络广义Ｄｅｌｔａ学习规则，从而使得整个控制系统具有很强的自、自学习能力。文中最后通过对系统进行的仿真研究证实了这种控制结构的有效性，仿真例子说明经过１００个周期学习后，其系统的跟踪误差控制在１％以内。     

基于改进GA的变风量空调系统优化控制仿真

针对变风量空调系统本身存在多变量、非线性、强耦合等问题,基本遗传算法很难起到很好的控制效果.现针对基本遗传算法的适应度值、交叉率和变异率进行改进,通过引入Sigmoid函数和高斯分布函数自适应调整公式来调整交叉率和变异率,并对适应度值进行自适应设计,构建一种改进遗传算法.并采用改进遗传算法对PID控制器参数进行在线调整,最后将改进的遗传PID控制器和基本遗传PID控制器分别对典型二阶系统、滞后系统进行控制仿真,并对变风量空调系统的冷冻水流量-送风温度,送风温度-房间温度,风机频率-风管静压这三个控制回路进行仿真研究;仿真结果表明:所提算法的动态性能好,系统超调量、上升时间均有所减少,同时具有较强的抗干扰性和鲁棒性,为变风量空调系统优化控制提供了一种可行控制方案.     

内模解耦单神经元自适应PID仿真研究

为了解决多变量大时滞系统的耦合问题,根据内模控制原理和单神经元的在线自学习能力,提出一种基于模型的单神经元自适应PID内模解耦算法,并详细分析了其在多变量大时滞系统中的解耦原理.内模解耦是运用解耦预估补偿器将一个多输人多输出的系统补偿为多个单输入单输出的系统、并将对象模型进行对角优势化,补偿后的主对角元素即可作为内模控制的预估模型.仿真结果表明,这种新的内模解耦算法具有相当好的解耦能力、较好的快速性和抗干扰能力.     

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.