基于OPC和Wincc的磨机负荷控制系统

针对以往磨矿自动控制过程延迟时间长及设备间通讯不便的问题,提出了基于OPC和Wincc的磨机负荷自动控制系统;用VB编写OPC客户端,并以Wincc作为OPC服务器,实现Wincc与VB客户端的数据交换;用高级语言编写磨机负荷控制算法,对经OPC通道传入VB的实时数据进行分析控制,最后将控制数据传送给底层设备,达到对磨机负荷实时自动控制的目的;运行试验表明,基于OPC和Wincc的磨机负荷控制系统能够有效地对磨机负荷进行控制并提高矿厂效益。     

氧化铝回转窑制粉系统磨机负荷的智能控制

氧化铝回转窑制粉系统采用回转窑余热产生的热风干燥煤粉时,由于热风温度低且变化频繁,常常导致制粉工况处于过负荷异常工况,出现"饱磨"故障,导致停磨,使负荷控制系统无法投入自动运行.本文提出了有规则推理的切换机制,在磨机负荷PI控制器和过负荷控制器之间进行智能切换.所提出的控制方法成功应用于氧化铝回转窑制粉系统,在热风温度低且变化频繁时,将磨机控制在出力最大的负荷范围内,避免出现故障工况.     

闭路球磨机的非线性动态辨识及最佳循环负荷量求取

1 引言磨机是水泥厂的主机之一,其能耗大,效率低。据有关文献介绍,水泥生产中约有70%的能耗用于粉磨作业,而用于粉磨功(有用功)的能耗仅占磨机耗电量的2%～10%,其余为损耗。因此,合理使用磨机与控制磨机负荷并使之在最佳工作状态下运转,是提高磨机粉磨效率和降低能耗的重要途径。粉磨系统具有非线性、大滞后和慢时变参数等特性,其最佳负荷即最大生产能力随着生产过程中原料的粒度分布,易磨性及研磨体研     

生料浆配料过程磨机负荷的混合智能控制

针对在氧化铝生料浆配料过程中难以采用常规方法来控制磨机负荷状态的问题,提出了由负荷状态估 计模型和负荷调整模型组成的磨机负荷混合智能控制方法．负荷状态估计模型根据磨机的振动与电流信号,采用规 则推理方法估计出磨机的负荷状态．负荷调整模型采用案例推理方法自动调节磨机给料量,将负荷控制在合适范围 内．该方法成功应用于某氧化铝厂生料浆配料过程中,长期运行结果表明,提高了磨机台时产能,减少了“堵磨”故 障发生次数,提高了生产效率并节能降耗．     

磨机负荷监测控制系统设计

文章介绍了磨机的运行特性,及其在选矿厂磨矿系统中的应用情况.针对磨机负荷难以测量的特点,分析了传统的基于磨机振动和磨机噪音的检测方法所存在的不足,并在此基础上对基于综合的磨机负荷测量方法进行了研究.     

水泥粉磨系统的DCS控制

介绍了水泥粉磨系统计算机集散控制系统的实现方法 ,着重讨论了水泥磨配料的自动控制和水泥磨负荷的智能控制。实际应用结果表明 :该系统提高了磨机喂料量和负荷的控制精度 ,可靠性高 ,具有明显的经济效益     

基于LabVIEW的磨机负荷自动测试与分析系统

根据磨机的运行特点和负荷测试要求,开发了一套基于LabVlEw的磨机负荷测试系统.该系统以图形化编程语言LabVIEW为软件开发平台,以声音、振动传感器,USB-9215A型数据采集模块和计算机搭建了PCDAQ通用硬件平台.将虚拟仪器技术应用到磨机负荷测试中,使测试系统搭建快捷、方便,人机界面友好,实现了信号采集、文件存取、数据处理和显示功能.现场测试表明系统测试、分析结果正确有效,完全可以满足实用要求.     

磨矿过程磨机负荷的智能监测与控制

磨机过负荷是磨矿过程的常见故障工况, 如果不及时、准确处理, 就会造成磨矿产品质量变坏甚至磨矿生产的停顿. 采用规则推理(RBR)和统计过程控制(SPC)技术, 提出了由SPC机制、过负荷监测模块和监督控制器构成的磨机负荷智能监测与控制方法. 该方法通过对磨机过负荷的智能监测与诊断, 由监督控制器自动修改控制回路的设定值, 通过控制回路的输出跟踪修改后的设定值, 使磨机负荷逐渐远离过负荷状态. 工业应用表明, 该方法能够实现磨矿生产的安全、稳定和连续运行.     

料位自寻优和解耦算法在制粉系统中应用研究

针对制粉系统多变量、强耦合、料位测量不准确造成的经济性能低等特性,提出了基于料位自寻优多神经元PID制粉系统解耦控制。根据现场采集的磨音信号、磨机负荷等参数,采用料位自寻优算法能实时搜索磨机最大出力,使系统始终运行在最佳工作点;根据系统在最佳工作点的料位控制量采用改进权重的神经网络PID算法,实现各层神经元的连接权重值调整,降低系统控制误差,使系统实现解耦控制。仿真和实际控制结果表明,该算法具有较高的准确率,能适应不同工况下出口温度、入口负压以及料位的稳定控制,不仅实现了制粉系统的闭环自动控制,而且提高了系统制粉效率,降低了制粉单耗,最终达到节能目标。     

磨机负荷级联模糊控制系统

根据磨机生产工况多变的特点,提出一种磨机负荷级联模糊控制方案,以增强控制系统的适应能力.实验结果表明,与单回路PID定值控制比较,该方法改善了负荷控制性能,提高了磨机生产效率,是一种有实用价值的磨机负荷控制方法.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

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.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

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.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.