基于VXI总线的8通道测频模块设计

基于频率测量的广泛应用性,设计了一种基于VXI总线的C尺寸8通道测频模块;在详细分析和理解VXI总线规范的基础上,采用CPLD设计了VXI总线寄存器基器件接口电路;采用信号调理电路和光电隔离电路对输人信号进行调理,使其转变成CPLD可识别的脉冲信号;基于多周期同步测频法,采用VHDL语言设计了模块的测频电路;调试结果表明,VXI总线接口电路原理正确,功能合理,接口电气性能满足总线规范的要求;测频功能工作稳定、可靠,测试精度较高.     

基于FPGA的VXI总线多功能模块设计

VXI总线多功能模块是某导弹自动驾驶仪VXI测试系统的关键模块,需要完成被测信号采集、特殊测试激励信号产生、频率测量和数字IO功能;文章首先简要介绍了模块的设计要求和总体设计;然后阐述了模块的各功能电路实现;接着重点论述了模块设计中采用扫描地址图谱实现多通道和量程动态切换、采用块传输实现VXI接口高速数据传输和采用RAM分时复用存储实现长时间连续数据采集等关键技术;应用这些技术研制的模块已应用于实际测试系统中,其性能良好,工作稳定;接口测试结果表明,模块的VXI接口设计极大地提高了数据传输速度。     

VXI内嵌式控制器的硬件设计与实现

VXM内嵌式控制器是VXI总线测试平台的重要硬件平台。介绍了一种基于嵌入式PC的VXI内嵌式控制器的硬件设计与实现,并以PCI－VXI总线接口设计为重点,详细讨论了同步／异步总线转换电路、具有系统控者能力的VME接口电路以及VXI扩展电路的设计与实现。     

基于VXI总线的航空串行总线测试卡研究

针对VXI总线测试领域串行总线测试卡设计开发成本高、集成度低、开发周期长的问题,提出了一种新的VXI总线测试卡设计方法;首先介绍硬件电路的总体结构,其中简要介绍了VXI接口电路的设计,重点介绍了功能模块即航空串行总线(以ARINC-429、MIL- STD- 1553B为例)接口模块的设计方法和思路;然后介绍了模块软件程序的设计;最后介绍了驱动程序的开发;实践应用显示,该模块工作可靠、性能稳定;利用该方法进行测试卡设计能够有效降低系统开发成本,缩短系统开发周期,具有较高的工程应用价值.     

VXI总线四通道LVDS数据传输模块设计

针对国内测试系统开发中出现的低电压差分信号(LVDS)技术需求提出了一种VXI总线四通道LVDS数据传输模块的设计实现方法;以FPGA作为控制核心,利用Verilog HDL设计实现了VXI接口和HDLC通讯协议设计,并通过基于VXI总线的块传输方式和乒乓存储技术,完成了大批量数据的接收;另外,为确保LVDS信号的完整性,结合实际设计和调试经验,文中还分析了LVDS接口信号印制板布线和布局问题;该模块已用于测试系统开发,并实现了测试系统与被测设备的视频信号传输;应用结果表明,模块传输速度为4Mbit/s时误码率小于10-6。     

8通道静态应变信号调理模块研究

在航空发动机的测试中,需要测量发动机的各种性能参数,如温度、压力、转速、流量、振动等,其中压力的测试是可以通过测量发动机叶片产生的应变来完成,通常应变测试系统包括应变片、信号调理器、数据采集模块和软件处理几部分;北京长城测控公司结合近几年开发航空发动机测试系统的经验,基于VXI总线测试技术开发了信号调理模块与数据采集模块高度集成的航空发动机测试系统,同时针对测试中存在的多种物理量开发了多种信号调理模块;文章主要针对静态应变信号调理模块的使用方法及在数据采集系统中的应用进行了介绍,并对关键电路的设计方法进行了详细说明。     

基于VXI总线雷达天线转动信号数字模仿器的研制

为了解决雷达伺服系统的测试问题及满足部队模拟训练的需求,设计了基于VXI总线雷达天线转动信号数字模仿器。系统设计了A16／D16寄存器基接口电路,开发了软面板和仪器驱动程序。同时雷达天线转动信号产生功能电路实现中采用了特殊的模拟信号存储技术,使得电路具有成本低,性能高的特点。实际测试表明．所研制的VXI总线雷达天线转动信号数字模仿器能够产生幅度、频率可控的兼容不同体制雷达的转动同步信号,并可驱动多套负载．应用前景广阔。     

VXI总线A24并行A/D连续采集模块设计

在VXI测试系统中,VXI总线连续采集模块对测试系统实时性能的提高具有重要意义.介绍了VXI总线A24/D16并行A/D连续数据采集模块设计方法.该方法采用CPLD实现了通用VXI总线A24/D16寄存器基接口电路、控制电路、中断电路.最终实现并行AID连续数据采集及存储.     

一种基于寄存器基器件的VXI总线接口设计

针对目前VXI接口电路模块需要使用大量芯片、接口响应速度慢的问题,提出了一种基于寄存器基器件的VXI总线接口设计方案,并对该方案功能进行了详细的分析。最后在具体应用中与早期的方案进行了性能对比,对比结果显示本方案具有明显的优势,可大大提高接口模块的集成度和速度,并解决了基于VXI接口电路的高速数据存储问题。     

基于FLEX 10K芯片的VXI总线接口电路设计

为了研制开发VXI模块化仪器,必须首先解决VXI总线接口电路的设计。文章给出了选用ALTERA公司的可编程逻辑器件FLEX 10K,在MAXPLUSⅡ环境下设计VXI总线接口电路的方法,并详细讨论了接口中几个主要功能模块的设计和实现。     

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     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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。