基于单片机的便携远程多路数据采集系统

为了在油井压裂过程中进行远程数据采集.设计开发了便携式远程多路数据采集系统.系统结构紧凑,采用AT89C52单片机作为中心控制单元.应用12位高精度并行A/D转换芯片AD574和8通道故障保护模拟开关MAX354实现8路数据采集;利用RS-485串行通讯进行数据传输,传输距离可达1.2km;接收端再将信号转换为RS-232电平,使用便携式手提电脑的串口接收数据.将采样数据存储在PC机中,便于数据的实时处理和分析.     

基于FPGA和TCP/IP的多路采集与切换系统设计与实现

为保证数据采集应用中系统远距离控制和数据传输的可靠性,及满足多路信号接口的切换与并行数据采集需求,设计了一种基于FPGA和TCP/IP的多路采集与切换系统。该系统以Xilinx Spartan-6系列的FPGA为主控芯片,可满足8组×13路通道的切换,及16路模拟信号的同步采集与实时传输,采用FPGA+TOE架构实现TCP/IP协议通信,并配备监测上位机。通过测试表明,该系统能够长期稳定地进行多路通道切换及高速采集与实时传输,使用便捷、可靠性高,在分布式采集领域中具有一定的应用价值。     

一个单片机串行数据采集及传输模块的设计

以AT89C51单片机为核心,使用12位并行A/D转换器AD574A、多路开关CD4051及多组RS-232驱动/接收器MAX232,设计了一个串行数据采集/传输模块。模块中主要分为两部分,第一部分由AD574A芯片和两个多路开关CD4051实现16路12位A/D转换,完成串行数据的采集;第二部分由AT89C51单片机和MAX232芯片实现与计算机间的串行数据传输。文中给出了硬件原理图和主要源程序。     

EtherCAT网络数据采集系统的设计与实现

针对很多领域中数据采集量大、数据采集点分布广、间距长等问题设计了一种基于EtherCAT工业以太网的网络数据采集系统;简介了EtherCAT网络通信原理和结构,详细阐述了系统的硬件设计:以PIC单片机为主控制器,采用一片AD转换芯片并配合数个模拟量多路开关实现多路数据采集,并完成了EtherCAT主站程序、从站应用程序的设计;最后,对采集系统进行了实验验证,实验结果证实了该网络数据采集系统的实用性和可靠性。     

模拟开关矩阵MT8808的性能及其应用

介绍了模拟开关矩阵芯片MT8808的性能及其应用，详细说明了单片机控制的多路信号开关矩阵的硬件电路设计和软件设计，还介绍了MT8808的级联技术。该矩阵芯片已成功应用于视频、音频的多路信号切换控制系统中。     

数据采集系统在温度变换器测试中的应用

温度变换器测试过程包含温循、高低温、常态测试等试验,测试内容多,测试任务繁重.为了提高测试效率与可靠性,开发了多通道数据采集系统.该系统基于LXI总线构成,用多路测量仪器作为硬件平台,复用开关作为多路之间的互相切换,从而实现数据采集和开关控制.该数据采集系统的特点是测量通道多、精度高,测量对象为温度变换器,同时能实现供...     

一种实用的数据采集监测系统的设计

数据采集系统，通常是为了将实时定时采集后，以数字量形式存储后进行分析，得到分析结果进行显示打印或报警。系统通常由传感器，线性放大器。多路模拟开关。采样保持器，A/D转换器，单片机芯片，扩展I/O口，存储器以及外接设备打印机。显示器等组成，其系统框图如图1所示。     

同基准16路电流型测温电路设计与应用

在许多实际的应用系统中,需要同时测量多点温度,为了解决多支路测温需要相同参考标准的问题,保证各路参数具有可比性;巧妙地设计同基准A/D转换电路,运用低导通电阻模拟开关构建矩阵开关进行分时切换各支路,有效地解决了多支路同基准测量问题;结合实际应用确定A/D转换器输入电路滤波电容大小与开关切换延时的关系;利用台阶电阻使A/D转换器的输入端的“零”电平得到抬升,偏离A/D转换器非线性段,解决了微小信号输入的测量精度;对于温度测量普遍使用的铂电阻传感器,利用模拟开关实现了铂电阻传感器静态下预热电流与测量状态下工作电流的电路转换,保证电路的信号稳定起到很好作用;在实际的应用系统中,检定数据和使用效果表明,同基准16路电流型测温电路具有高稳定度、高精度特点,适用于各种相参测量系统中使用。     

基于C8051F340数据采集系统的设计

针对某设备运行状态实时监控的需要,研制了一个高速数据采集装置,该装置采用带USB接口的C8051F340单片机为核心,同时具有多路信号切换,A/D变换等功能。采用Keil uVision3进行固件开发,实现了温度压力超限报警功能。该系统的电路结构简单、可靠。     

AVR单片机在多回路数据采集器中的应用

介绍了AVR高档单片机MEGA系列的性能和特点，提出了一种以ATmega128微处理器为核心器件的多回路、高精度、快速数据采集器的设计方案。采集器系统通过模拟开关对8路互感器输入的电流以及开关量输入的报警和状态信号进行采集，充分利用微处理芯片内A／D转换器进行数据处理和存储等，并给出了AD采集处理的硬件接口电路和软件编程实现。     

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     

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.