矿用隔爆型低压馈电开关的现状及趋势

简述了矿用隔爆型低压馈电开关的现状、趋势以及存在的问题，指出了大容量高分断能力的矿用隔爆型低压馈电开关是今后发展的方向。     

JKB-1200型馈电开关电子保护器

DW80系列馈电开关是目前我国煤矿井下低压馈电线路的主要控制设备,但该系列开关在送电前无法对馈电线绝缘电阻进行检测、在井下对短路保护不能进行整定、也无法区分短路跳闸故障与漏电跳闸故障。为此,研制成功了JKB-1200型馈电开关电子保护器。文章对该保护器的工作原理、结构、性能作了较详细的介绍。     

一种新型的智能低压馈电开关的设计

文章介绍了一种应用于煤矿井下配电系统的新型智能低压馈电开关,阐述了该馈电开关的硬件和软件设计。该馈电开关以PLC为核心,设置了过载保护、短路保护、漏电保护、过压和欠压保护,而且具有人机对话和通信功能。现场测试结果表明,该馈电开关精度高,可大大提高煤矿供电系统的安全性和可靠性。     

矿井低压馈电开关的改造

针对现有矿用低压馈电开关存在保护功能少、数据上传不全、误差大、无故障录波等问题,提出了一种采用新型综合保护器对其进行改造的方案,即更换低压馈电开关内置综合保护器,改造馈电开关内部辅件和线路,从而确保电力监控数据准确、即时上传,并实现开关的远程合分闸、复位、漏电等功能,满足了电力监控管理系统的需求。     

矿用隔爆型自复电式低压真空馈电开关研制成功

<正> 辽源矿务局煤矿电器设备厂在煤科总院抚顺分院的协助下,研制成功了矿用隔爆型自复电式低压真空馈电开关。该产品主要应用在煤矿井下低压供电系统,     

短讯

KBZ1-400/1140矿用隔爆型真空馈电开关KBZ1-400/1140矿用隔爆型真空馈电开关由天地科技股份有限公司常州自动化分公司研制推出。适用于含有爆炸性气体甲烷和煤尘的煤矿井下。在交流50 Hz、1 140 V、额定电流400 A及以下的线路中,该真空馈电开关既可作配电系统的总开关,也可以作配电支路首、末端的分开关。该真空馈电开关正常工作时,可在LCD屏上显示电压、电流、功率、电度、运行状态等数据;当电网线路出现过负荷、漏电、过电压、短路时,能自动地进行纵、横向选择,快速地去除故障线路并记忆故障参数,同时开关闭锁,只有解除故障并人工复…     

矿用双控制器馈电开关的设计

文章介绍了一种基于双控制器的矿用馈电开关的设计方案。该馈电开关采用单片机和DSP双控制器设计,实现了数据采集处理和故障判断功能的分离,大大提高了运行速度和智能化水平,还具有过载、缺相保护、短路保护、不平衡保护、漏电闭锁保护、漏电保护和选择性漏电保护功能。测试结果表明,该馈电开关性能稳定,运行速度快,精度较高。     

基于PLC的矿用智能低压馈电开关选择性漏电保护系统

文章阐述了基于零序电流方向的选择性漏电保护原理,介绍了一种基于PLC的矿用智能低压馈电开关选择性漏电保护系统的软、硬件设计方案。实际应用表明,该系统能够可靠、快速地实现选择性漏电保护,且具有较强的抗干扰能力。     

基于STM 32的智能低压保护器的研制

矿用隔爆低压馈电开关适用于具有爆炸性危险气体(甲烷)和煤尘的矿井中,是煤矿井下低压电网中的关键设备,其正常运行与否直接关系煤矿生产的安全和连续性。而低压馈电开关的智能化程度主要取决于保护器的可靠性和灵敏性。随着煤炭工业的快速发展、高产高效矿井的建设、煤矿井下机械化和自动化的提高,对采煤自动化技术的发展提出了更高的要求,对矿井供电的连续性、可靠性和安全性也提出了越来越高的要求,因此对矿井低压电网综合保护系统的研究具有重要的理论和应用价值。     

基于嵌入式系统的矿用隔爆型馈电开关监控系统的设计

将基于ARM7的嵌入式系统集成到矿用隔爆型馈电开关中,实现了井下矿用隔爆型馈电开关现场数据的实时采集和井下工业以太网的快速接入;地面监控站利用套接字编程,实现了与嵌入式馈电开关监控系统的交互;利用ASP.NET构建基于B/S架构的Web服务平台,实现了馈电开关的信息查询和远程智能监控。基于ARM7嵌入式系统的矿用隔爆型馈电开关监控系统提高了井下馈电开关的操控水平,也为煤矿井下其它电气设备的智能远程监控系统的设计提供了借鉴。     

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.