城市供水工程SCADA控制系统

介绍了某供水工程SCADA控制系统的设计方案.所采用的SCADA控制系统是完全基于工业以太网的分布控制系统,代表了供水工程自控系统的最新应用方向.     

工业生产过程中的SCADA应用分析

在分析数据采集与监视控制系统(SCADA)结构的基础上,通过文字和图表清晰的描绘出了SCADA在工业生产中的控制原理,并深入剖析了SCADA在生产过程控制中的功能与应用.     

基于国产密码技术的SCADA系统在新能源领域的改造应用研究

数据采集与监视控制系统(Supervisory Control And Data Acquisition,SCADA)是工业控制系统的核心,但因SCADA系统中节点分布比较分散,且通信过程缺乏认证及安全措施,因此极易成为被攻击的目标。近年来发生的"震网"病毒事件等加剧了工业SCADA控制系统信息安全问题的严重性。为了保证新能源领域SCADA系统的自主可控,本文针对新能源领域SCADA系统进行嵌入国产密码技术的研究与改造,并且提出其对应的改造方案。     

油田供汽SCADA系统

SCADA (Supervisory Control and Data Acquisintion)系统,全名为数据采集与监视控制系统,是对分布距离远、生产单位分散的生产系统的一种数据采集、监视和自动控制系统.本文主要阐述油田供汽SCADA系统的工作原理、体系结构、功能特点,详细叙述了 SCADA系统在油田供汽站的应用.     

基于可靠ZigBee组网技术的电力SCADA应用

SCADA系统概述SCADA(Supervisory Control And Data Acquisition)系统,即数据采集与监视控制系统。SCADA系统的应用领域很广,它可以应用于电力系统,铁道交通系统、水利环保系统、石油化     

工业控制网络安全系列之五 SCADA通信协议的漏洞、攻击及应对

<正>1简介工业控制系统(ICS)中,SCADA(监控和数据采集系统)的每一步操作都是严格遵照RTU(远程终端单元)发出的指令来完成的,所以,想对采用SCADA的工业控制系统进行破坏,黑客只要修改相关数据或者阻碍数据传输就可以达到目的。由于SCADA系统的通信协议在设计之初就欠缺安全考虑,所以     

基于IO地址分离和频谱分析的SCADA系统异常检测模型自动化构建

随着诸如监控和数据采集(SCADA)系统之类的工业控制系统越来越多地连接到企业网络和互联网,其安全性受到极大威胁。研究SCADA系统的异常检测问题时,考虑到了SCADA系统的通信流量通常是高度周期性的。针对SCADA系统提出一种基于输入输出(IO)地址分离和频谱分析的异常检测模型自动构建的方法。实验在真实的SCADA测试平台上进行,结果表明该方法性能优于其他建模方法。     

SCADAvantage TM在油气领域的应用

SCADA系统在信息化和控制系统中起到非常重要的作用。一个成功的SCADA系统最后的目标是怎样的呢？无论是对于油气田还是长输管线，会不断的进行新管线的建设或者新的油气田开发，如井口的不断加入以及其它一些后续的开发。这对于SCADA系统来说，     

霍尼韦尔Experion PKS系统SCADA通信解决方案

介绍Honeywell EPKS控制系统与MODBUS设备间的数据采集通信解决方案,包括SCADA设备硬件连接及软件组态实现,实现不同控制系统间的数据读写访问。     

SCADA系统实时信息语音平台的设计与开发

本文研究了SCADA系统中语音平台的设计以及实现语音平台的思路和关键技术,重点介绍了工业语音平台的结构设计以及通过OPC协议获取SCADA系统信息和使用微软的SAPI技术实现语音输出的主要步骤和编程技巧.该语音平台的成功应用使控制系统可以通过语音播报的方式把实时信息及时传递给用户,扩展了控制系统的HMI功能,可推广应用到目前大多数具有OPC Server的SCADA系统中,具有使用简便,可靠性高的特点.     

A method of defuzzification based on the approach of areas' ratio

The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.     

Ethical and legal issues for writing researchers in an age of media convergence

With the convergence of digital media into ever-widening social and technological networks for creation and distribution, the contexts for writing and the study of writing and writers have certainly changed. Researchers must navigate a dense matrix of ethical and legal issues in all phases of research when studying the ever-changing processes and products of digital communications. In this article, I draw from numerous sources to articulate a few of the challenges facing digital writing researchers in this age of convergence, focusing on issues of representation (researcher, participant, third-party), issues of informed consent, and issues of copyright and fair use.     

New debates on learning support

Abstract In the present debate on knowledge management and multimedia support of human learning, the word 'mediation' (of conduct) is often used as a natural correlate and rough equivalent to the word 'mediatisation' (of information). It is suggested that the distinction between the two words points to a basic difference between two types of processes which are crucial to a much needed rethinking of the conception and design of humanmachine interaction (HCI).
A redefinition of the 'appropriateness' of media support as the quality of the help to people's self-help rather than of direct control of their behaviour is proposed. Such a redefinition implies a radical shift of paradigm allowing for approaches to human learning as a cognitive activity in its own right. Another view of technological mediation is advocated, in keeping with some recent developments in HCI.     

An approach to the synthesis of fuzzy stabilization systems with a priori unknown model of an object

A method of synthesis of fuzzy stabilization systems for a broad class of dynamic objects under the assumption that the mathematical model of the object is not known a priori is proposed. The control is formulated in the form of a proportional law of adjustment as a function of a macro-variable; the square of the Euclidean norm of the phase variables is adopted as the macro-variable. An analogous variable characterizes the distance of the object from the equilibrium position. Despite the simplicity of the control law, its sign remains constant due to the fact that the macro-variable is positive-definite over the entire phase space. The switching times of the signals are determined by fuzzy identification of the system’s dynamic modes on the basis of measurement of the derivatives of the macro-variable.     

HUYGENS' PRINCIPLE,PHYSICS AND COMPUTERS

We discuss the emergence of topology from a consideration of set extensions in General Systems Theory. Boundaries arise in a natural way, separating independent elements or regions of the system. Our aim is a unification of Etter theory, Kron's method of Tearing and Jessel's formulation of Huygens' Principle. This should make explicit the equivalence between the objective, structural, holographic and the subjective, relative definitions of information, sought in Bowden (1994b), reprinted in this Special Issue. It connects the abstract generalisations of Schrodinger's equation and Bom's rule derived in probabilistic Etter theory with the real world of electrical and other physical phenomena in General Physical Systems Theory. This paper can be considered as a continuation of Bowden (1990; 1994a) and as a response to Bowden (1994b), reprinted in this issue.

We review the ideas behind Kron's Method of Tearing and Jessel's Principle of Secondary sources (both special cases of the above theory) and their equivalence. We follow Hiley's argument in Hiley (1996) to show how Schrodinger's equation can be thought of as specifying the evolution of (a series of) tearings in continuous space. These can be shown on a commutative diagram as a series of similarity transforms. We compare this with Etter's derivation (Etter, 1998). We describe briefly a recently published derivation of Maxwell's equations from a non-commutative algebra and show how they fit onto a related commutative diagram. Finally we make some comments on applications of the general theory to computer systems. This paper is a series of vignettes of work in progress. It is designed to point the direction of work to come in Constructive Physics.     

动态规划求解中国象棋状态总数

中国象棋空间复杂度是分析中国象棋博弈难度的重要指标，中国象棋空间复杂度分析是一个计数问题，即求解中国象棋状态总数。根据中国象棋棋子的着法特征，该问题可分解为若干子问题，利用动态规划分别解决这些子问题，能够求出中国象棋状态总数的精确解。实验得出中国象棋状态总数约为7.54×10^39.88，过去许多文献描述的中国象棋状态总数是不准确的，远远高估了中国象棋状态总数。基于动态规划的计数方法也可以用于计算其他棋类的空间复杂度，也能够用于寻找空间复杂度较低的残局棋型，为构建中国象棋残局库提供依据。     

Innovative uses of ICT in Chilean schools

Abstract This paper presents some of the results of the study of seven cases of innovative pedagogical practices using ICT. The study was performed in the framework of the application of SITES M2 in Chile. The results are divided in two sections. First is a summary of each case, highlighting its innovative characteristics that serve as models of 'good practice' for Chilean teachers. Second, the results of the analysis of what teachers did are outlined; the impact on students and the type of teaching and learning activities in use. Results show that these projects did not provide evidence of having impact on students' learning as defined in the national curriculum. However, they show that students participating in these projects could learn other things, had the opportunity to develop abilities defined as cross-curricular and practised ICT related skills. The analysis of the teaching and learning activities highlights some deficiencies in the way that teachers implement new teaching strategies.     

Forage quality of savannas — Simultaneously mapping foliar protein and polyphenols for trees and grass using hyperspectral imagery

Savanna covers about two-thirds of Africa, with forage quantity and quality being important factors determining the distribution and density of wildlife and domestic stock. Testing hypotheses about the distribution of herbivores is hampered by the absence of reliable methods for measuring the variability of vegetation quality (e.g. biochemical composition) across the landscape. It is demonstrated that hyperspectral remote sensing fills this gap by revealing simultaneously the spatial variation of foliar nitrogen (crude protein) as well as the total amount of polyphenols, in grasses and trees. For the first time, the pattern of resources important for feeding preferences in herbivores (polyphenols and nitrogen) is mapped across an extensive landscape and the modeled foliar concentrations are shown to fit with ecological knowledge of the area. We explain how estimates of nitrogen (crude protein) and polyphenols may be scaled up from point-based observations to reveal their spatial pattern, and how the variation in forage quality can influence the management of savannas, including farms, communal grazing areas, and conservation areas. It provides a glimpse of the choices herbivores must face in selecting food resources of different qualities.     

Complement of Source Equation of Elastic Line

A new notion of joint, defined in terms of the state of motor (active or locked) and type of the elastic or rigid element, gear and/or link that follows after the motor, is introduced. Special attention is paid to the motion of the flexible links in the robotic configuration. The paper deals with the relationship between the equation of elastic line equilibrium, the “Euler–Bernoulli approach” (EBA), and equation of motion at the point of elastic line tip, the “Lumped-mass approach” (LMA). The Euler–Bernoulli equations (which have for a long time been used in the literature) should be expanded according to the requirements of the motion complexity of elastic robotic systems. The Euler–Bernoulli equation (based on the known laws of dynamics) should be supplemented with all the forces that are participating in the formation of the elasticity moment of the considered mode. This yields the difference in the structure of Euler–Bernoulli equations for each mode. The stiffness matrix is a full matrix. Mathematical model of the actuators also comprises coupling between elasticity forces. Particular integral of Daniel Bernoulli should be supplemented with the stationary character of elastic deformation of any point of the considered mode, caused by the present forces. General form of the elastic line is a direct outcome of the system motion dynamics, and cannot be described by one scalar equation but by three equations for position and three equations for orientation of every point on that elastic line. The choice of reference trajectory is analyzed. Simulation results are shown for a selected robotic example involving the simultaneous presence of elasticity of the gear and of the link (two modes), as well as the environment force dynamics.