不确定性奇异时滞系统的鲁棒H∞控制

研究了含不确定性线性奇异滞后系统的鲁棒H_∞控制问题.其中不确定性是范数有界的.为此首先给出了相应的无控制标称系统内稳定且满足H_∞范数界的一个充分条件.然后讨论了含不确定性奇异滞后系统鲁棒H_∞控制问题有解的一个充分条件,并同时给出了控制器的设计,控制器可由线性矩阵不等式解得.最后举例说明本文方法的正确性.     

时变不确定离散时滞系统的H∞鲁棒控制

研究了一类线性不确定离散时滞系统的H_∞鲁棒控制问题,其时变不确定项是范数有界的,但无需满足匹配条件.基于线性矩阵不等式 (LMI)方法,得到了可H_∞鲁棒镇定的一个充分条件.通过求解一个特定的线性矩阵不等式,即可获得H_∞状态反馈控制器.具体算例说明了该方法的有效性.     

滞后广义系统的状态反馈H∞控制

研究了一类状态方程和输出方程均带有时滞的滞后广义系统的H_∞控制问题.利用线性矩阵不等式,首先给出滞后广义系统零解渐近稳定且具有H_∞范数约束的充分条件,进而分别设计无记忆和有记忆状态反馈控制律,保证闭环系统具有上述性能,同时基于线性矩阵不等式的解得到了相应控制器构造方法.最后给出一个数值算例说明文中结论的有效性.     

具有时滞的奇异系统H∞控制

针对具有时滞的奇异系统H_∞输出反馈控制问题, 利用Lyapunov泛函方法, 得到闭环系统稳定且具有H_∞-范数界γ的充分条件, 基于相应的LMI可行解给出了动态控制器显式表示. 最后, 数值例子表明了该方法的正确性.     

不确定模糊Delta算子系统的鲁棒H∞控制

研究了一类T-S模糊Delta算子系统的鲁棒H_∞控制问题.首先利用LMI形式给出了模糊Delta算子系统鲁棒镇定的充分条件,然后构造了可使闭环系统鲁棒稳定且对可允许的参数变化满足H_∞性能的状态反馈控制律.本文结果统一了连续与离散模糊系统的鲁棒H_∞镇定设计结论,数值算例说明了方法的可行性.     

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.     

模糊系统H∞控制器设计的LMI方法

应用LMI(线性矩阵不等式)方法,研究了T-S模糊系统H_∞控制器的设计问题.首先给出了T-S模糊系统基于状态反馈H_∞控制存在的两个新的充分条件.新条件不但简洁而且把模糊子系统间的相互作用表示为由子系统的系数矩阵构成的矩阵不等式.然后新条件被转化为可直接应用Matlab求解的线性矩阵不等式.最后应用线性矩阵不等式方法和Matlab,给出了T-S模糊系统H_∞控制器的设计方法.     

基于LMI的约束系统H∞控制及其滚动优化实现

在LMI优化框架下,讨论有时域硬约束线性系统的H_∞控制问题.首先提出了一种基于LMI优化的状态反馈方法,并给出了闭环系统保证H_∞性能和满足时域硬约束的条件.在此基础上,融合预测控制的滚动优化原理讨论了一种滚动时域H_∞性能控制方法.通过对H_∞性能指标γ的在线最小化,闭环系统能实时协调控制性能要求和硬约束,并充分利用有限的控制能力提高控制性能.     

具有状态和测量时滞不确定系统的鲁棒H∞状态估计

考虑一类已知状态和测量时滞且范数有界参数不确定连续时间系统的鲁棒H_∞状态估计问题. 这个问题解的充分条件由二个代数Riccati不等式给出, 它可以保证存在一个渐近稳定状态估计器使得对于所有不确定性从外界干扰到输出估计误差的传递函数满足指定的H_∞指标. 以上这些结果可以推广到一类未知状态和测量时滞且范数有界参数不确定连续系统的鲁棒H_∞状态估计问题, 对于已知状态和测量时滞系统, 所得状态估计器与参数不确定性无关, 而与时滞有关. 对于未知状态和测量时滞系统, 其状态估计器不仅与参数不确定性无关, 而且与时滞也无关.     

基于模糊观测器的非线性MIMO系统H2/H∞模糊状态反馈控制

研究了非线性系统H₂/H_∞模糊状态反馈控制问题.采用局部线性化方法,用T-S模糊线性模型逼近非线性系统,用模糊观测器重构系统状态.在希望的H_∞干扰抑制约束下,通过最小化H₂控制性能指标,实现了模糊状态反馈次优控制.通过将优化问题转化成2个特征值问题(EVP),应用线性矩阵不等式(LMI)优化方法求解,使问题的求解大大简化.所设计的闭环系统在平衡点是局部二次型稳定的,系统抗扰性能和动态性能均较好.     

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。