500kV变电站3／2接线的保护死区分析

详细分析了500kV变电站3／2断路器接线的保护死区及死区故障时的保护动作情况，深入解析了贵州电网内利用断路器失灵保护快速切除死区故障的原因及其不足，并提出了解决的方案以供讨论。     

改进的QPSO算法在电网故障诊断系统中的应用

电网故障诊断系统通常基于建立的解析模型,通过分析保护和断路器的动作信息来推断可能的故障位置,从而识别保护与断路器的故障元件和误动作;根据保护动作原理,构建了一种改进的解析模型,并采用改进的量子粒子群算法对其目标函数进行优化求解;该模型不仅充分考虑到了保护和断路器的误动与拒动、断路器失灵保护等问题,且能辨识告警信息的误报和漏报;实验结果表明改进的算法不仅使故障诊断结果更精确,并能使故障情况很清晰地表示出来,有利于故障的及时恢复,同时使模型的运算速度和稳定性也进一步得到了提高。     

探讨断路器时间测量中的几个问题

断路器是电力设备中最重要的控制和保护设备之一,而机械特性试验主要是检验断路器短路开断和关合能力。文章对目前断路器时间测量中出现的问题进行了分析,并提出了解决办法。     

500kV断路器因空气压力低告警导致断路器控制保护回路断线分析

针对天生桥换流站500kV三菱断路器因空气压力低告警导致断路器控制保护回路断线这一情况,根据工作站中出现的信号,结合断路器的控制、保护二次回路,对信号及其出现的缘由进行分析,评估断路器控制保护回路断线时,可能出现的安全生产风险,发现目前存在的问题,并对这些问题提出解决方案。     

浅析断路器在低压配电系统中的应用

断路器在电网系统中起到过载保护的作用,目前,断路器常用于低压配电系统中,保护低压系统的运行。断路器是低压配电系统的重要组成,提高低压供电的可靠性,防止出现线路问题,充分发挥了保护作用,确保低压供配电系统的正常运行。因此,本文通过对断路器进行研究,分析其在低压配电系统中的应用。     

断路器状态多信息融合评估方法及IEC 61850建模

在研究并分析了断路器状态评估方法的基础上,提出了一种基于断路器维修曲线的多信息融合评估方法。根据断路器状态评估方法和IEC 61850建模规范,绘制了断路器分/合操作次数相对于分断跳闸动作电流的曲线图。结合断路器的预估寿命和最大通断电流等因素评估断路器触头寿命,形成了断路器的维修预警机制,从而实现了断路器的在线监视、保护、测控等设备功能的集成。该方案将原断路器智能组件功能集成到保护测控装置,通过制造信息声明(MMS)服务,将装置现有逻辑功能状态信息上传至后台服务器,以实现实时监视功能。将该方法集成于保护测控装置智能电子设备(IED)中,实现了断路器触头机械寿命预警监视功能。与现有其他断路器在线监测设备相比,该方法可降低站端设备的数量和成本。同时,IEC 61850建模的规范化有利于装置的功能扩展。     

基于数据融合的温度对漏电断路器动作特性的影响研究

漏电断路器是保证用电人员生命财产安全的保护电器.电子式漏电断路器因其工艺简单、成本低廉,在国内得到了广泛应用,市场占有率达90％,但其动作特性易受环境温度的影响导致丧失漏电保护功能.对漏电断路器动作特性的温度影响进行了研究;设计了温度环境试验,检测电子式漏电断路器在不同环境温度下其动作特性变化情况;并应用数据融合技术对试验所得数据进行了数据处理.通过分析数据处理所得结果,总结出了温度与电子式漏电断路器动作特性之间的关系,为进一步的研究工作提供了基础.     

简析变压器断路器失灵保护

本文分析了目前运行中的主变失灵保护回路存在的问题,并讨论了解决方案.     

模糊遗传优化在高压断路器智能操作中的应用

断路器作为电力系统中重要的控制和保护设备，其运行可靠性对电力系统的运行安全和可靠有重要的意义。随着断路器智能操作理论的提出，针对电力系统的复杂性和故障的多样性，使得系统状态和断路器分闸速度之间很难用精确的数学模型表示，提出采用模糊控制建立断路器开断速度特性的运动模型，并采用遗传算法对模糊模型的隶属函数进行优化，使得智能操作模糊控制的隶属函数在全局得到优化，并得出了优化后的隶属函数，为断路器智能控制的理论深入提出一条新的思路。     

基于RBF网络的断路器电流自适应保护研究

针对传统断路器电流保护方法存在受系统运行方式影响、整定困难、智能化低等问题,提出了基于RBF的断路器电流自适应保护算法,并给出了算法的模型;该算法融合了RBF神经网络的故障检测和电流自适应保护;首先通过RBF网络检测负载线路的电流故障,然后用电流自适应算法进行保护;在对神经网络进行训练时,利用PSO算法对RBF神经网络的参数进行优化以此来提高网络的泛化能力和学习能力;然后采用优化后的PSO-RBF神经网络对电流故障进行诊断;实验表明,该算法较大地提高了断路器智能化管理水平。     

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.