基于PLC的电镀生产线监控系统设计

介绍了MCGS和PLC在电镀生产线中的应用,用MCGS件和PLC设计了生产线自动运行的过程,提高了电镀生产线的自动化程度和生产效率。实现了对电镀生产线的系统控制,使系统具有很强的适应能力,可方便完成自动、手动和连续运行控制及相互之间的切换;整个程序采用结构化的设计方法,具有调试方便,维护简单,移植性好的优点。     

基于PLC的电镀生产线自动行车控制系统设计

为了进一步提高现代工业中物料运输的工作效率,本文以电镀生产线的自动行车控制系统作为主要研究对象,通过引入PLC控制模式,进而从硬件和软件两方面对基于PLC的电镀生产线自动行车控制系统展开了全面的设计和研究。     

高炉上料控制系统的设计与研究

根据沙钢6#高炉工艺要求,基于S7-400系列PLC及工控组态软件Win CC,设计一套高炉上料生产线自动控制系统,以提高生产线的效率。     

PLC在金矿设备改造中的应用

本文设计了一套基于PLC的监控系统,应用于金矿碎矿生产线控制系统改造.系统由性价比高的PLC,工控机和组态软件构成.通过PLC编程,实现了对生产设备的全面自动控制、联锁保护、运行状态监测等功能;运用组态软件,设计了具有良好的人/过程接口能力的监控画面,实现了过程信息的集中显示和处理.实际运行表明,该系统功能设计合理,运行可靠,显著提高了生产效率.     

基于WinCC的自动化生产线监控系统

本文针对自动化生产线设备,介绍了自动监控系统的软硬件构成,分析了WinCC与PLC之间的通讯机制,并对利用组态软件WinCC设计自动监控系统的方法以及开发过程中遇到的问题和解决途径进行了讨论。     

S7-400在烧结生产线自动控制中的应用

介绍宝钢股份南通钢铁有限公司烧结自动控制系统的构成,该系统由Siemens S7-400PLC、Simatic wincc6.0组态监控软件,实现了烧结生产线的自动控制。自投产以来,系统运行稳定。     

PLC在合成油生产线控制系统中的应用

根据合成油生产线的工艺流程,采用S7-200系列PLC和工控机对生产线进行控制。由PLC对生产线中的流量、温度、液位等信号进行采集,将工控机设置的参数与采集数据进行对比分析,根据分析结果对各种工业阀门和泵进行控制,实现了生产的自动化,结合力控组态软件在工控机中制作的监控操作界面,不仅提高了生产效率,而且操作直观方便。文中介绍了S7-200系列PLC合成油生产线控制系统的设计方案、系统组成、硬件设计与软件设计,阐述了PLC在合成油生产线中对各种传感器信号的采集处理及对各种工业用阀门与泵的控制方法,同时也阐述了结合工控机使用力控组态软件对生产线进行操作控制的方法。     

电吸附除盐系统的设计

针对电吸附水处理技术的工艺特点,设计了一种基于PLC和上位组态软件的控制系统,实现对水处理生产线的过程控制;该设备现场运行表明：自动化程度高,人机界面友好,运行可靠。     

基于PC与软PLC的气动物流生产线控制系统设计

本文在介绍了气动物流生产线结构和功能的基础上,着重阐述了应用CANopen现场总线与组态及软PLC软件CoDeSys改造物流生产线监控系统的方法,监控计算机（PC）运行CoDeSys软件作为主站通过PC适配卡与物流生产线各工作单元的I／O从站进行通信,构成基于PC与软PLC分布式控制网络;通过组态软件创建动态监控界面,实现对物流生产线工作过程的实时监控。     

PLC在电镀生产线中的应用

利用PLC实现对电镀生产线的系统控制，使系统具有很强的适应能力，可方便完成自动，手动控制和相互之间的切换；整个程序采用结构化的设计方法，具有调试方便，维护简单，移植性好的优点。     

The influence of IT: perspectives from five Australian schools

Abstract Information and Communication Technologies (ICT) are now widespread in Australian schools but with variation in how, where, when and how much they are used. Computers may be located in a computer laboratory, distributed throughout the school, or students may use their own laptop computers. IT may be a subject in its own right or ICT may be used across all areas of the curriculum. It is how ICT is used in the school setting that is important in providing students with the skills to be participate in a 'knowledge society'. This paper examines the ways in which information and communication technologies influence teaching and learning in five Australian schools. Data were gathered through observation, interviews and document analysis in schools operating at the elementary and secondary grades in relatively technology rich environments. Each of the schools participated in the Australian component of the Second Information Technology in Education Study – Module 2 (SITES-M2) of innovative pedagogical practices. Several of the studies were of specific projects where ICT was the key enabler of the learning programme. Others focused on an entire school's approach to ICT as an agent for changed approaches to learning.     

利用MODIS EVI时间序列数据分析福建省植被变化(2000~2017年)

以全国森林覆盖率最高的福建省为研究对象,利用2000~2017年夏季的MODIS EVI植被指数数据和气象与非气象因子进行协同分析,以揭示近17年福建植被的时空变化及其影响因子。结果表明:研究期内福建的EVI均值整体上升,从2000年的0.454上升至2017年的0.505,17 a间上升了11.2%,表明福建省的植被整体处于变好的状态,且在中部和西南部的变化最明显。相关分析表明,在研究期内,气象因子(气温和降水)对EVI变化的影响不显著,植被的变好主要为非气象因子的作用。EVI的提高主要得益于2003年福建省建设生态省后森林覆盖率的提高,并和2012年开始的水土流失治理有明显关系,这说明人类活动的积极作用对福建植被的变好起到了关键的作用。     

关联规则挖掘技术研究进展*

为帮助人们深入研究关联规则挖掘技术,总结了关联规则的分类方法、评价方法以及相关技术的最新进展,特别是对关联规则的主要算法进行了详细的介绍,并探讨未来的发展方向。该研究比较系统全面,对将来进一步深入分析关联规则挖掘技术具有指导意义。     

Desktop publishing in education

Abstract The term 'desktop publishing' has received much media coverage in recent months in both the commercial and educational press. School-based 'desktop publishing' packages are at the moment poor imitations of full-specification systems. This paper discusses the state of desktop publishing in education today and demonstrates the weaknesses of the systems available for use in the classroom. The skills required for desktop publishing are interrelated in a complex way and cannot be presented in a hierarchical fashion. A model of the functional processes involved is suggested in the paper and analysed in terms of the skills required.     

A Review of:“Safety in Manual Materials Handling.” By COLIN G. DRURY. (Cincinnati: US Dept. of Health,Education & Welfare, 1978.) [Pp. viii+ 209.]

The extension force against resistance was recorded in 23 postures for 12 subjects to find explanations for the decrease in back strength in asymmetric postures. A reduction in muscle force in asymmetric postures was found up to 40%, but was strongly dependent on the plane in which asymmetry occurred, and on the posture to which it referred. A quantitative relationship between the forces exerted in different asymmetric postures is discussed, as a basis for formulating universal ergonomic guidelines for optimal working postures. The reduction in force in different asymmetric postures can be explained by length of the muscle, the activation of the muscle, and the moment angle of the muscle.     

Ecosystem functioning of protected and altered Mediterranean environments: A remote sensing classification in Doñana, Spain

Spatial heterogeneity in ecosystem functioning is a key component of ecological variability requiring special attention in the context of global change. A large history of human use has produced high physiognomic heterogeneity in Mediterranean ecosystems. However, the consequences for ecosystem functioning remain insufficiently understood. We analyzed spectral indicators of matter and energy fluxes in the land surface to classify the functional ecosystem heterogeneity in a Mediterranean region covering different management histories and protection types. We specifically analyzed the spatial variability in seasonal and annual patterns in the Normalized Difference Vegetation Index (NDVI), surface temperature (T_s) and albedo from five Landsat ETM images. Then we classified numerically this variability into ecosystem functional types (EFTs) and explored their seasonal dynamics in terms of photosynthetic radiation absorption and evapotranspiration. We identified eight main EFTs with ecologically relevant differences including contrasting dynamics in fPAR seasonality, great variation in incoming radiation reflection and differing evapotranspiration rates, particularly during the water-limitation period. Functional variability in natural vegetation mostly consisted in dissimilar annual rates of NDVI and albedo, whereas differences in seasonality were more evident in transformed areas. Similarly, the spatial distribution of EFTs was partly associated to protection, with two EFTs exclusive of protected areas and comparatively higher functional diversity in humanized areas. Landform effects on water availability in protected areas and human activities under different ecological settings were seemingly responsible for the large functional diversity of the region. We advocate for the explicit incorporation of multifunctional ecosystem heterogeneity in ecosystem management and monitoring designs.     

Back to the Future: An Historical Perspective on the Pendulum-Like Changes in Literacy

This article focuses on the pendulum-like change in the way people read and use text, which was triggered by the introduction of new reading and writing technologies in human history. The paper argues that textual features, which characterized the ancient pre-print writing culture, disappeared with the establishment of the modern-day print culture and has been “revived” in the digital post-modern era. This claim is based on the analysis of four cases which demonstrate this textual-pendulum swing: (1) The swing from concrete iconic-graphic representation of letters and words in the ancient alphabet to abstract phonetic representation of text in modern eras, and from written abstract computer commands “back” to the concrete iconic representation in graphic user interfaces of the digital era; (2) The swing from scroll reading in the pre-print era to page or book reading in the print era and “back” to scroll reading in the digital era; (3) The swing from a low level of authorship in the pre-print era to a strong authorship perception in the print era, and “back” to a low degree of authorship in the digital era; (4) The swing from synchronic representation of text in both visual and audio formats during the pre-print era to a visual representation only in print, and “back” to a synchronic representation in many environments of the digital era. We suggest that the print culture, which is usually considered the natural and preferred textual environment, should be regarded as the exception.     

A new mining approach for uncertain databases using CUFP trees

In the past, many algorithms have been proposed to mine frequent itemsets from transactional databases, in which the presence or absence of items in transactions was certainly known. In some applications, items may also be uncertain in transactions with their existential probabilities ranging from 0 to 1 in the uncertain dataset. Apparently, the processing in uncertain datasets is quite different from those in certain datasets. The UF-tree algorithm was proposed to construct the UF-tree structure from an uncertain dataset and mine frequent itemsets from the tree. In the UF-tree construction process, however, only the same items with the same existential probabilities in transactions were merged together in the tree, thus causing many redundant nodes in the tree. In this paper, a new tree structure called the compressed uncertain frequent-pattern tree (CUFP tree) is designed to efficiently keep the related information in the mining process. In the CUFP tree, the same items will be merged in a branch of the tree even when the existential probabilities in transactions are not the same. A mining algorithm called the CUFP-mine algorithm is then proposed based on the tree structure to find uncertain frequent patterns. Experimental results show that the proposed approach has a better performance than UF-tree algorithm both in the execution time and in the number of tree nodes.     

DTN网络中PRoPHET路由协议的改进

对DTN网络中PRoPHET路由协议进行了改进,在采用基于效用值来选择DTN路由下一跳的同时,充分利用了临时簇内的端到端的连接.另外,当网络中发生了DTN拥塞时,把拥塞节点上紧急程度低的信息转移到临时簇的周围其它节点,然后传输紧急程度高的信息到拥塞节点.仿真结果表明,与DTN网络中路由协议PRoPHET相比,改进后的路由方法提高了数据包的成功发送率,降低了平均发送延时.