基于ADS7812的数据采集系统设计

现代信息采集系统中A/D转换是关键,本文介绍了利用ADS7812进行A/D转换的数据采集系统。文中对ADS7812的特性进行了分析,给出了ADS7812与51单片机接口的程序代码,最后提出应用ADS7812应注意的一些问题。     

用C开发AutoCAD的ADS应用程序

文章以程序HZBS．C为例，对ADS应用程序的开发技术作了详细介绍。阐述了ADS开发环境，ADS与AutoCAD的接口，以及外部函数定义、调用的机制。讨论了ADS应用程序的编译、连接和运行等问题。     

基于DSP与CPLD的ADS7805多通道数据采集

设计了利用TMS320LF2407A与EPM3032A控制的ADS7805多通道采集系统的逻辑结构,介绍了系统的工作原理,详细描述了ADS7805、DSP及CPLD之间接口的硬件与软件设计。     

基于LPC2478的触摸屏设计

介绍了利用工业级芯片LPC2478与ADS7843设计触摸屏幕的实际方案,还介绍了LPC2478与ADS7843的特点,硬件电路的设计,采集方式的选取与设计以及ADS7843采集流程。对触摸屏设计出现的问题,给出了详细的解决方案。     

触摸屏的工作原理及典型应用

简要介绍触摸屏的结构及工作原理,并以Burr-Brown公司的触摸屏控制芯片ADS7843为例,介绍触摸屏应用的典型电路和操作。由于ADS7843内置12位A/D,理论上触摸屏的输入坐标识别精度为有效长宽的1/4096。     

TMS320F28335的I2C总线与ADS1115的通信设计

简单介绍了TMS320F28335的外设I2C总线的通信协议,详细描述了ADS1115芯片的工作原理及TMS320F28335外设I2C总线与ADS1115通信的驱动程序,并利用芯片ADS1115实现了循环采集4路模拟量,且最终获得的实验结果在允许的范围内,验证了数据传输的格式跟I2C的协议是一致的.     

基于CPLD的OMAP-L137与ADS1178数据通信设计

介绍高精度采样芯片ADS1178及新型工控芯片OMAP-L137,并采用SPI接口结合CPLD控制芯片,实现OMAP-L137与ADS1178间的数据通信。测试表明,既节约了处理器资源,又满足了工业环境中各类控制系统数据采集的实时性和准确性的要求。     

提升移动ADS解决方案——增加虚拟移植功能仅需五步

在“突破ADS障碍”（本刊2006年12月号）这篇文章中。我介绍了如何建立基本的移动自动部署服务（Automated Deployment Services，ADS）解决方案，可以在不影响或不重新设置生产环境网络的情况下，进行Windows操作系统的移植。现在，更上一层楼，我将介绍如何利用移动解决方案将物理机移植到虚拟机环境。虽然我所介绍的是如何扩展移动ADS的安装，但是同样的概念可以应用到在网络中安装ADS。     

模糊单片机NLX230及其接口软硬件设计

简单介绍了模糊单片机NLX230的结构及其特点，描述了NLX230的典型接口及其开发软件ADS230。     

基于USB的ADS1258传感器信号采集系统

介绍了ADS1258模数转换器工作原理,设计了一种由ADS1258和CY7C68013芯片构成的高精度信号采集系统,并介绍了其软件设计和数据格式。该系统主要应用于多通道传感器信号采集平台。经测试,ADS1258在自动扫描模式下采集速率达到3kSPS,能很好地应用于低速高精度数据采集场合。     

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。     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).