基于MyPSO-BP的黄酒发酵温控系统

在 Labview组态软件、西门子PLC300和温度传感器构成的温度控制系统基础上,提出一种新的黄酒发酵温度控制系统,将带交叉因子的粒子群优化(PSO)算法应用到BP神经网络(MyPSO-BP)比例积分微分(PID)控制中。改进的PSO算法初始化神经网络的权重和阈 值,可以更好地在线整定PID参数,增强系统的稳定性和鲁棒性,减小误差。对系统进行Matlab仿真实验,结果表明,该系统相较于传统的神经网络PID控制器具有更好的温度控制性能。     

无人机涡喷发动机的BP网络控制

该文介绍了由反向传播神经网络（BP网络）构成神经网络PID控制系统的基本结构和原理,针对传统BP算法存在的收敛速度慢、容易陷入局部极小值的缺陷,选用了标准的数值优化算法（LM算法）,此算法具有极好的快速性;对某无人机涡喷发动机的神经网络PID控制进行了仿真研究,并与常规PID控制进行了比较研究,仿真结果表明：采用此算法构成的神经网络PID控制具有响应速度快、稳态误差小、算法简单的优点;用一个神经网络作为控制器,控制地面和空中多点对象是可行的,但要进行实际应用,还有待于进一步的研究.     

两轴数控转台的控制算法研究

研究电力系统的优化控制问题,针对提高系统的品质特性的要求,在两轴数控转台中采用传统的PID控制参数难以整定跟踪性能。将神经网络引入到转台控制PID参数的寻优过程中,设计了基于BP网络的PlD控制算法器,建立了转台控制系统的数学模型,将基于BP网络的PID算法的控制进行仿真。仿真结果表明所设计基于BP网络的PID算法器跟踪精度高、性能稳定、鲁棒性强,证明提高了控制系统的精度和跟踪性能。     

基于BP神经网络整定的PID控制

传统PID控制在控制系统中有广泛的应用,但是由于其在参数整定过程中对于对象模型过分依赖,并且参数一旦整定计算好后,在整个控制过程中都是固定不变的,而在实际系统中,由于系统状态和参数等发生变化时,过程中会出现状态和参数的不确定性,系统很难达到最佳的控制效果．为了改善传统PID控制的效果,又充分利用现有PID控制的研究成果,采用BP神经网络对PID参数进行整定,并对该系统进行了仿真分析．仿真结果表明,采用BP神经网络整定的PID控制较传统PID算法及BP网络算法都有较大程度的提高．     

BP神经网络PID控制算法在农作物干燥控制系统中的应用研究与设计

针对传统PID控制算法对于农作物烘干控制方法存在的不足,以实现对农作物高效、节能的干燥为目的,设计了一种基于BP神经网络PID控制算法的新型农作物干燥控制系统;系统采用DS18B20、SHT10为信息采集源,将采集到的温湿度信息传递到以C8051F340单品机为核心的控制器进行整个干燥过程的控制决策;算法仿真及实验结果表明,基于BP神经网络PID控制算法的控制器具有较高的精度和较强的适应性,最终可以获得满意的控制效果。     

基于合作粒子群算法的PID神经网络非线性控制系统

PID神经元网络 (PIDNN)模型为一种新型的神经网络模型,兼有PID与神经网络的共同优点,应用于复杂的控制系统.取得优良控制性能,但其后向传播算法 (BP)限制了该模型的应用范围.为实现对非线性多变量系统的有效控制,扩展神经网络的应有范围,本文采用PIDNN神经网络设计了多变量PIDNN神经网络 (MPIDNN)控制器,并用本文作者提出的合作粒子群算法 (CPSO)取代了传统BP后向传播算法,通过比较MPIDNN_CPSO、MPIDNNCRPSO、MPIDNN_PSO和MPIDNN_BP4种控制器的控制性能,仿真结果表明,基于CPSO算法的MPIDNN控制器实现了对非线性多变量不对称系统的有效控制.与传统的BP算法相比,CPSO算法提高了控制系统的稳定性、精确性与鲁棒性.     

基于神经网络的PID自整定控制系统

文章介绍了一种应用神经网络技术建立的PID自整定控制系统,给出了系统结构,详细分析了BP神经网络和RBF神经网络的结构和学习算法。该系统采用3层BP神经网络,其输出为PID控制器的参数;通过变结构的RBF神经网络辨识控制对象,将得到的输出对输入的梯度信息提供给BP神经网络,BP神经网络根据该信息优化PID控制器参数。仿真结果表明,该系统对于参数扰动较大的非线性系统,其收敛速度快、动态响应能力强、稳定性好,且具有较强的鲁棒性和适应性。     

基于改进型粒子群算法的PID神经网络控制系统

针对传统的PID神经网络(PIDNN)应用范围受限及积分误差规则难以获取的问题.为实现对非线性多变量系统的有效控制,拓展神经网络控制系统的应用范围,提出了基于改进型粒子群算法在PID神经网络控制系统设计中的解决方案,取代了传统的BP反向传播算法.仿真结果表明,与传统的PIDNN相比,系统的稳定性、鲁棒性及精确性都有了明...     

BP神经网络PID控制器在工业控制系统中的研究与仿真

针对实际被控对象的时变性和非线性的特点,本文将基于BP神经网络PID的控制器应用于工业控制系统中,同时设计了三层BP神经网络并对BP神经网络PID控制器的算法进行了分析。仿真结果的分析表明：本文所设计的BP神经网络PID控制器在跟随性能、抗扰性能和鲁棒性能方面表现出了良好的控制效果。     

神经网络PID在温度控制系统中的研究与仿真

本文提出一种基于BP神经网络的新型智能PID控制方法和一些BP神经网络的基本概念。同传统的PID控制相比较．神经网络智能PID控制有许多优点。把BP神经网络的PID控制方法应用到工业领域的温度控制系统中，仿真结果表明：这种控制方法具有较高控制精度和较强的适应性以及良好的控制效果。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.