基于GSM模块的远程监控系统

文章介绍了基于GSM的远程监控系统，该系统由上住机的监视软件和下位机的硬件电路两部分组成。给出了监控系统的硬件结构组成，并详细介绍了上下位机的工作流程：下位机主要用于对现场数据采集，PC主要用于数据和视频文件管理，通过对GSM发送AT命令来实现相互间的串行通信以达到监控目的。实践证明，利用GSM短信息实现远程监控是一种经济、可行的方法。     

基于Lab Windows／CVI的温室环境控制系统设计

详细介绍了一种基于虚拟仪器（Lab Windows／CVl）平台的温室环境控制系统的设计方法，并从硬件、软件上加以实现。上位机PC通过串口向下位机ATMEGA8单片机传送指令，下位机按要求采集温室系统的相关数据，上传给上位机，送数据库保存和处理。     

基于多线程的环境监控系统下位机的设计

为提高环境监控系统的稳定性,节约系统资源,提出了一种由下位机、传输网络和上位机组成的环境监控系统的设计方案,详细介绍了该系统中下位机的硬件及软件设计。该下位机硬件以ARM9处理器S3C2410为核心,软件采用多线程应用程序同时处理多个任务,并采用信号量和互斥量实现线程间的同步。实际应用表明,该系统运行稳定,提高了系统效率。     

基于RS485总线的PC与单片机多机通信系统设计

介绍了一种基于PC机和多单片机组成的主从式控制系统的设计方案。以PC机作为上位机,多台80C51单片机作为下位机,实现上位机与下位机以及下位机与下位机的通信。硬件方面,介绍了系统中各电路的原理,设计了实现该电路的原理图;软件方面,分析了上位机和下位机之间的串行通信,并完成了多机通信的设计。实验证明,该系统具有一定的先进性和良好的实用性,可靠性。     

基于Pcap01芯片的高精度微电容检测系统设计*

本文介绍了一种基于Pcap01的微弱电容检测系统的硬件、软件设计和实验测试。系统硬件主要由微电容测量芯片Pcap01、单片机STC12LE5A60S2最小系统以及供电电路构成。系统软件包括下位机的C程序和基于Labview软件实现的上位机。下位机实现了电容数据采集、Pcap01与单片机之间的SPI通信以及将数据发送给上位机的功能。上位机可实现数据处理、实时显示以及测试数据的存储。实验测试结果表明,该系统的数据检测均误差可低至2.9093fF。系统具有精度高,抗干扰性强,实时性的特点,实现了电容式生物传感器与接口电路的集成。     

智能化多路绝缘耐压自动测试系统的研究

为了克服测试方法和测试人员给绝缘耐压测试结果带来的误差，提出了一种智能化多路绝缘耐压自动测试系统的设计方法。介绍了该系统的工作原理、硬件组成及软件实现。系统采用上、下位机形式构建，上位机采用可视化强的VB6．0进行数据管理与分析软件设计；下位机通过单路程控绝缘耐压测试仪进行测试所需应力施加和信号采集，并利用PLC根据优化控制算法进行测试通道的选择。长期现场运行表明：系统具有操作简单、人机化程度高、性能稳定、测试结果准确、故障诊断快速等特点。     

智能数字传送器设计

在PC机与多个单片机的串行通信基础上,从硬件和软件两方面完成了智能数字传送器的设计.智能数字传送器实现的是一台上位机(PC)机和8台下位机(单片机)的串行通信,上位机软件采用Visual Basic编程,作出十分直观的人机界面,并通过串行口将下位机的数据传送给上位机,上位机可作出应答信号,同时上位机(PC)机可向下位机(单片机)发出数据请求.系统具有对数据的修改,显示和报警等功能,目前在工业控制领域中应用非常广泛.     

基于AD7677和M EGA64高速数据采集系统的设计

开发了一套基于AD7677和MEGA64的高速数据采集系统。下位机硬件系统主要由信号调理模块、A/D转换模块、MEGA处理器模块、串口通信模块组成。它能够实现信号的采集及前端处理,并能通过串口总线与上位机通信。上位机软件系统采用NI公司生产的Lab Windows/CVI 8.0工控软件,实现对数据的存储、后端处理及显示。重点阐述了系统原理及硬件、软件的设计。     

变电站监控系统的一种设计方案

本介绍了变电站监控系统的一种设计方案,描述了Windows环境下软件的实现方法、上、下位机之间通信的实现及通信程序清单,下位机的硬件构成及工作原理。     

基于nRF24L01的无线电子记分系统设计

无线记分系统的设计分为发送端和接收端两部分。发送端控制程序通过RS232串口通信发送比分数据到单片机控制的下位机,并经由nRF24L01无线射频模块天线进行数据发送;接收端通过单片机控制的无线射频模块天线接收数据并使用8段LED数码管显示记分情况。系统的整体设计包括硬件电路、软件程序设计;发送端上位机界面程序采用VB6.0设计,发送端下位机和接收端单片机程序采用C51。给出了软件设计流程图、硬件实物运行现场图。测试表明,系统运行性能良好。     

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).