基于逆系统的赖氨酸发酵多变量解耦内模控制

针对赖氨酸发酵过程的时变、非线性和高耦合性,提出基于逆系统的赖氨酸发酵多变量解耦内模控制方法。根据动态递归模糊神经网络(DRFNN)的非线性辨识原理离线建立发酵过程的逆模型,将得到的逆模型串联在发酵系统之前,实现了发酵过程输入输出解耦线性化,从而得到伪线性系统;对复合后的伪线性系统采用内模控制。仿真结果表明,该方法能够适应赖氨酸发酵过程模型的不确定性和参数的时变性,具有较强的鲁棒性,且结构简单,易于实现。     

基于支持向量机的船舶锅炉智能控制研究

在非线性系统逆控制的思想基础上,采用SVM辨识系统的逆模型,设计并实现了基于SVM的逆控制.为克服基于SVM输入输出数据辨识的逆模型不精确引起的逆控制不足,提出了一种SVM逆控制与模糊控制相结合的复合控制策略.在复合控制中,模糊控制器主要用来实现前期控制快速响应的要求.在此期间,逆辨识器在线调整其参数并完全传递给逆控制器.SVM逆控制器在后期起主要作用,以消除对被控系统的稳态误差.由于此复合控制系统中增加了反馈环节,因而比直接逆控制具有更优的性能和鲁棒性,有效解决了逆控制模型精确度要求的问题.将其应用于用锅炉蒸汽压力控制系统中,仿真证明了该复合智能控制策略是有效和实用的.     

基于支持向量机广义逆的直线永磁游标电机内模解耦控制

针对直线永磁游标电机这一多变量、强耦合的非线性系统, 提出一种基于支持向量机广义逆内模控制的方法. 在证明其数学模型存在广义逆的基础上, 通过支持向量机来辨识原系统的广义逆系统, 经复合后得到具有线性关系的伪线性系统, 然后引入内模控制方法设计附加控制器以增强整个系统的鲁棒性. 仿真结果验证了所提出方法具有良好的解耦性能和抗干扰特性.

     

基于T-S逆模型的航空发动机解耦控制

为了解决发动机控制系统中存在的耦合现象,以自适应逆控制原理为基础,提出了一种基于T-S逆模型的解耦控制器;该方法利用模糊T-S模型来辨识发动机的逆模型,从而得到实现解耦效果的伪线性化模型,再运用神经网络PID控制器的在线整定功能提高系统的动态性能和鲁棒性,使系统综合性能最优;仿真结果表明,该控制器具有理想的解耦效果,在发动机工作包线范围内具有良好的自适应能力.     

基于支持向量机的电弧炉逆内模控制器

针对三相交流电弧炉电极调节系统的耦合问题,提出了基于支持向量机的逆内模解耦控制策略.根据广义电弧炉对象的Taylor近似模型直接推导逆控制律,消除三相之间的耦合,避免了在线辨识逆模型计算量过大的问题.另外,在内模结构中引入非线性补偿,当系统参数变化和受到外部干扰时,保证了系统的鲁棒性.系统的稳定性和鲁棒性通过Lyapunov方法进行了分析,最后的仿真与实验结果验证了控制器的有效性.     

多变量时滞过程二自由度Smith预估控制方法

针对工业系统中普遍存在的多变量时滞过程,提出了一种二自由度Smith预估控制的方法。通过在被控过程前串联反向解耦矩阵,实现标称系统的完全解耦。在此基础上,运用Dahlin控制算法和内模控制方法,对解耦后的过程分别设计了设定值跟随控制器和干扰抑制控制器,并基于最大灵敏度实现了干扰抑制控制器参数的鲁棒整定。仿真结果表明:该方法设计简单、整定方便,而且具有良好的跟踪特性、抗干扰特性和鲁棒性。     

磨煤机制粉系统解耦内模控制器的设计及仿真

本文针对工业过程中常见的多变量时滞耦合输入输出系统,基于内模控制结构提出了一种多变量解耦内模控制设计的方法,该方法设计的内模控制器同时具有解耦器和控制器的作用。其优点是能够实现标称系统输出响应之间的近似或完全解耦,并且改善了系统的大迟延的特性。并与PID对角矩阵解耦设计方法相对比,结果表明：解耦内模控制器设计方法有更好的鲁棒性。     

基于模糊神经网络α阶逆系统的发酵过程多变量解耦控制

将逆系统方法与模糊神经网络相结合, 提出一种基于模糊神经网络®阶逆系统的发酵过程解耦控制方法. 在分析了系统可逆性的基础上, 利用模糊神经网络建立发酵过程的非线性逆模型, 然后将得到的模糊神经α阶逆系统与发酵过程串联复合成伪线性系统, 最后设计专家控制器实现高性能闭环解耦控制. 仿真结果表明, 提出的解耦控制方法能够适应发酵过程模型的不确定性和参数的时变性, 具有较强的鲁棒性, 克服了解析逆系统解耦控制方法依赖于过程模型和对模型参数的变化很敏感的缺点, 且结构简单, 易于实现.     

基于一阶不确定项估计律的机械臂鲁棒控制研究

针对多自由度机械臂控制系统的模型参数误差、关节摩擦力以及外部输入扰动等不确定项,设计了一类一阶误差估计律;结合基于机构动力学名义模型的输入输出反馈线性化控制算法,对六自由度刚性机械臂的时变轨迹跟踪控制进行了研究,理论上证明了设计的鲁棒控制器是全局渐进稳定的.仿真结果表明该控制策略对系统的各类不确定项具有很好的鲁棒性,能够实现高精度的轨迹跟踪控制.     

基于惯量辨识的测试转台自适应内模控制

为了降低系统模型参数变化对测试转台控制系统的影响,提出了基于惯量辨识技术的自适应内模控制方案.首先建立了某型号测试转台数学模型,设计了测试转台内模控制器,在此基础上采用基于扰动转矩观测器的惯量辨识算法来辨识测试转台转动惯量的变化情况,然后通过模糊控制器根据转动惯量的变化自动调整内模控制器的参数,从而确保了控制器的控制性能.仿真和实验结果表明,该控制方案对惯量的变化有着很强的自适应性,提高了测试转台控制系统的抗干扰性能和系统的鲁棒性,取得了较好的控制效果.     

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.