发电机转子滑环在运行中损坏原因分析

介绍某燃气发电厂#1机组在做完甩负荷试验后的启动黑字程中所发生的发电机转子滑环烧损的故障情况,详细分析了导致故障的原因和采取的措施.     

300MW机组冷态启动的优化

机组的优化启动，是火电厂提高经济效益最直接有效措施之一，电力体制改革的实施。使得火电厂更加重视自身的发电成本，实现机组的快速启停可以降低电厂的发电成本，提高电厂的经济性。     

燃气电站汽轮机组旁路系统设计

为了改善汽轮机组的启动性能,协调机、炉间的汽量平衡,减少机组循环的汽水损失,格尔木燃气电站设置了一套高低压两级串联旁路装置,缩短了启动时间,减少了工质损失和启动费用,对机组快速启动特别是热态启动更有利。     

电潜泵长距离变频启动分析与试验

边际无人采油平台和深海采油要求潜油电泵地面控制设备具备远距离拖动潜油电机的能力.本文针对潜油电泵机组启动中存在的问题,分析了潜油电泵机组启动的特点,提出解决长距离潜油电泵机组启动理论方法,并进行了实验验证.     

大型无刷励磁同步电动机的启动及控制

启动及控制方案是影响大型无刷励磁同步电动机能否安全稳定运行的重要问题。从大连石化公司新区加氢裂化装置8062 kW进口同步电动机的启动计算入手,较为详细介绍了该机组的启动的一拖一及一拖二方案,同时针对机组的保护、控制、励磁与软启动既相互独立又需要协调一致的特点,对一些重点和难点问题进行了分析,并提出了解决办法。该系统在大连石化公司运行效果良好,对大型同步电动机组的启动及控制具有一定的指导意义。     

抽水蓄能机组调速器智能启动策略探讨

本文基于抽水蓄能机组调速器启动控制策略相关分析的基础上,探讨抽水蓄能机组调速器的智能化启动策略及开机控制过程,促进抽水蓄能机组调速器实际应用中问题的解决,最大程度上维护抽水蓄能机组的快速平稳开机并网。     

大型高压电动机一拖二启动技术的实践研究

因配套原因两台功率与负载特性相差较大的高压电动机组必须选用一套启动设备对两台机组进行一拖二控制.高压交流电动机液态软启动装置具有良好的可调性,可自动根据两台机组不同的启动特性设置最佳的启动参数,从而实现一套启动设备同时启动两台电机的功能.通过两台容量相差较大的大功率高压交流电动机共用一套液态软启动装置实现启动参数匹配的实际工程应用,介绍了液态软启动装置可调整性的技术优势.     

旁路系统在300MW机组启动过程中的运用

叙述了汽轮机高低压旁路系统作用、功能及特点,并介绍了旁路系统在300MW汽轮发电机组冷态启动过程中和非标准中压缸起动过程中的运用,为300机组启动过程中旁路系统灵活使用,使机组处于最佳工况提出了宝贵经验。     

模糊控制在单元机组锅炉给水阀门自动切换控制中的应用

某电厂300 MW单元机组控制系统采用西门子TELEPERMME DCS集散控制系统,在对其锅炉给水系统阀门切换的改造过程中,利用模糊控制理论,根据实际运行状况及运行资料,通过大量的实验分析,设计出切实可行的给水阀门切换逻辑,使燃煤锅炉给水系统给水阀门实现自动切换,解决了大容量单元机组燃煤锅炉实现全程给水自动控制所必须解决的一个关键问题。本系统的投运不仅节约了改造、更换给水系统所需的大量资金,由于机组实现自动启动,大大缩短了启动时间,使机组启动过程中消耗的燃料量明显下降,经济效益十分显著;同时也给出了模糊控制技术在控制工程中实际应用的一种思路。     

西门子S7-400 H系统在造粒机组上的应用

介绍了西门子S7-400H系统在聚丙烯造粒机组上的应用,包括控制系统的硬件配置情况、典型控制功能和第一故障原因闪光报警系统的实现方法。研究分析了FB41功能块的引脚功能、挤压造粒机筒体压力不稳和混炼电机连续启动现象的成因,解决了工艺参数控制不稳和混炼电机连续启动的问题。设备运行情况表明,西门子PLC满足机组对控制系统的要求。     

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.