电气柜逻辑测试仪通信系统

主要对地铁电气柜逻辑功能测试仪通信系统进行了研究和设计. 电气柜逻辑测试仪通信模块包括两部分: 系统层和管理层的通信以及管理层和测试层的通信. 在电气柜逻辑测试仪中, 系统层和管理层的通信数据量大、频率高, 采用CAN总线通信方式, 而管理层和测试层的通信距离近, 数据少, 采用RS485通信. 在硬件设计的基础上, 又设计了通信软件, 经现场调试, 设计的通信模块能够实现系统间的可靠通信.     

地铁车辆电气柜逻辑测试仪的软硬件设计

通过对电气柜逻辑测试仪的需求分析,设计了采集输出模块、通信控制模块和电源管理模块,研究了如何利用VC++自动导入EXCEL格式的连接清单表,并利用深度优先算法作为搜索规则将清单表生成类似电气线路图的连接关系表。经过几种车型电气柜的现场调试后,该逻辑测试仪能够快速有效地检测出电气柜的线路故障和逻辑功能故障。     

城轨车辆电气柜逻辑功能测试技术的研究

针对人工检测车辆电气柜造成的漏检和错检,研究设计了一种电气柜逻辑功能测试仪。通过对该测试系统的自动检测技术进行研究,重点分析了如何自动导入连接清单表,分类处理生成连接关系表,以及自动生成逻辑检测步骤的过程。经过几种车型电气柜的现场调试后,该逻辑测试系统完全达到了预期的测试目的,能够方便的检测出线路是否正确以及逻辑功能是否正常。     

多对象同步检测的新型气密测试仪设计

为了解决传统和当前大部分检漏仪一次仅能对一个测试对象进行检测的问题,对一种多对象同步检测的差压式气密测试仪进行了设计;该气密测试仪以基于ARM9的控制系统为主机端,以基于AVR的4个检测系统为采集端,通过独立的RS485串口通讯,完成控制系统与多个检测系统的信息交互;在此基础上,结合Linux操作系统的多线程机制、单片机和Qt/Embedded编程技术,建立完整的仪器检测控制软件系统,实现了多个测试对象进行同步检漏的功能;与普通的检漏仪相比,仪器的泄漏测试效率和自动化程度得到显著地提高,同时具有高精度高稳定性的特点,更适合在批量生产中使用。     

制作和维修的帮手——微型测试夹

电子制作和维修人员在调试任何电子电路时,都必须从检测各测试点和器件的引脚做起,无论使用示波器、万用表、频率计、逻辑分析仪、IC在线测试仪对器件进行测量,还是使用信号发生器、函数波形发生器、可编程数据信号发生器输出测试信号,首先遇到的问题就是测试端、输出端如何与被测器件连接,否则测试将无从谈起。     

集成电路芯片测试仪设计

设计制作了一个集成电路芯片测试仪,以STC90C516RD+单片机为核心,12864液晶显示器作为显示模块,采用了无线模块与电脑通信.该芯片测试仪能对常用的74系列芯片、CD系列芯片,以及LM系列和UA741组合逻辑芯片进行功能测试;能通过12864显示芯片的逻辑符号、逻辑表达式、芯片的功能以及状态转换图;能够将测得的型号通过无线串口发送到PC上位机.通过测试说明本设计制作的集成电路芯片测试仪在芯片检测,电路维修等方面具有重要意义.     

局域网连通性测试简易方法

在进行局域网网络布线和线路维修时,通常使用网络电缆测试仪进行连通性测试。网络电缆测试仪有专业测试仪和简易测试仪之分。专业测试仪不仅能测试网络的连通性、接线的正误,还可以测试双绞线的阻抗、近端串扰、衰减、回返损耗、长度等参数,这确实能带来不少方便,但动辄几千元、上万元的价格令人望而却步。于是,只有几十元的简易网络测试仪就成了我们这些非专业网管人员的首选。但是,使用简易网络测试仪进行电缆连通性测试时,往往需要一个人主控测试仪主机,另一个人在网线的另一端协助操作,这给测试工作带来了极大不便。笔者有一种简易方法…     

城轨车辆电气柜故障诊断方法研究

城轨车辆电气柜种类繁多,结构复杂,若依靠人工检测的方式进行故障的排除,不仅诊断效率低且可靠性差;通过对多个城轨车辆电气柜的具体分析,提出一种动态提取有向图结构模型并生成测试序列的算法,利用图的最优路径算法进行测试自检,最后使用一种适应性测试诊断树来完成故障的定位与隔离;实验表明,该诊断方法能够有效地对城轨车辆电气柜的故障进行诊断,且对于不同拓扑结构的城轨车辆电气柜具有良好的适应性。     

热成像技术在动车组中的应用研究

在动车组调试阶段利用红外热成像技术对电气系统进行检测,能够快速、有效的发现接线端子松动、负载不平衡、过载等不易察觉的异常现象。对主要的电气部件及接线部位进行数据采集并结合测试点的发热状态拟建立基础数据库,为电气系统异常故障诊断提供一种快速、便捷的定位方式,进一步提升电气调试工艺水平。     

高速突发模式误码测试仪的FPGA实现方案

突发模式误码测试仪与一般连续误码测试仪不同,其接收端在误码比对前要实现在十几位内,对具有相位跳变特点的信号进行时钟提取和数据恢复,并且在误码比对时须滤除前导码和定界符,仅对有效数据进行误码统计。本文提出一种基于FPGA实现的高速突发模式误码测试仪设计方案,并介绍该方案的总体设计过程,以及FPGA中主要功能逻辑模块的工作原理和控制系统的设计。该测试仪应用于1.25GHz GPON系统突发式光接收模块的误码测试中,具有较好的性能和实际意义。     

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.