嵌入式网络终端的语音传输系统设计

根据嵌入式网络终端的特点及VOIP技术原理,设计了一款基于WinCE的嵌入式语音传输系统。此系统实现了嵌入式网络终端之间的语音通信,以及网络终端和PC机之间的语音通信功能,具有较强的可扩展性。     

热定型机尾气余热回收效率监测系统

目前纺织印染企业热定型机的能耗大,能源利用率低。为了节能降耗,采用了热定型机尾气余热回收装置,设计了一个针对该装置的热能回收效率监测系统。系统包括采集模块和监控中心。采用CAN总线构建网络进行通信。利用嵌入式实时操作系统μC/OS-II进行任务管理和中断响应。用户界面使用嵌入式图形系统UCGUI进行设计,通过高性能的电阻式触摸屏实现用户交互。经过实验测试和现场运行证明,系统具有实时性强、网络响应快、受环境影响小等优点。     

基于LonWorks的嵌入式网络监控系统的设计

设计了一种基于LonWorks总线和嵌入式系统的监控通信网络。系统采用MSP430单片机作为任务调度和嵌入式系统移植的主处理器,提高了系统运行的实时性和稳定性。DDE服务器实现了数据访问与交换等网络通信功能。总线技术与Web网络相结合,使用户能够通过信息网络监控界面方便地了解现场情况,更便于实现远程监控、诊断和维护功能。     

基于嵌入式技术的工业通信管理机的开发及应用

本文主要对嵌入式技术系统、嵌入式工业通信管理机的开发及其应用进行研究,重点分析了嵌入式工业通信管理机的设计构想、应用功能开发,并结合实际工程应用情况,对未来工业通信管理机的发展进行展望,以供参考。     

基于LPC2210微处理器嵌入式网络通信系统终端设计与实现

伴随信息通讯技术、网络技术、电子技术的飞速发展,嵌入式系统终端也开始受到关注,寻求具有网络通讯的功能;文章所研究的嵌入式系统的网络通信采用ARM作为嵌入式开发平台,系统采用SmartARM2200开发板,使用支持仿真和嵌入式跟踪的LPC2210微处理器;结合网络通信系统,最终选择具有TCP/IP协议的嵌入式uCLinux操作系统,构建系统文件,完成嵌入式TCP/IP设计;并利用socket函数实现数据的接受、发送和校验等,实现服务器端和客户端的通信;最后在ARM7平台SmartARM上运行带有Linux内核的uClinux操作系统上进行试验,实验证明了所设计的通信系统数据传输的实现及可靠性。     

基于嵌入式网络的数据采集与分布式计算系统

采用将网络的开放分布和DSP高速信号处理的优势相融合的技术,给出了系统详细的软硬件设计和工作原理,以及通过嵌入式网络接口与上位机通信和采用XML-Socket技术数据传输的设计和实现过程.实验验证了系统在工业环境中与多种传感器配合使用实现分布式数据采集与实时计算功能的可靠性、稳定性.     

基于网络环境的嵌入式PLC软件平台设计与实现

该文介绍了一种嵌入式系统新的设计方法:嵌入式PLC,详细介绍了嵌入式PLC的原理、功能,嵌入式PLC软件平台的硬件设计、内核设计、关键技术及特点,在此基础上,还介绍了利用嵌入式PLC构成通信网络的方法及实现。实际应用表明:利用嵌入式PLC开发嵌入式系统,容易实现网络的互连、信息集成和功能扩展,提高了系统开发效率,缩短了开发周期。     

基于嵌入式DSP以太网接口的设计与实现

本文以数字信号处理器和网络控制器为核心,设计了嵌入式DSP系统接入以太网硬件平台,并简化网络层次体系结构.完成相应的网络应用软件的设计,实现了嵌入式系统通过以太网与计算机进行通信功能.     

基于ARM构架的工业注塑机控制器设计

为把嵌入式技术应用到工业控制器设计领域上来,分别以S3C2440和S3C4480为上、下位机硬件核心芯片,Linux和μC/OS-Ⅱ为上、下位机软件平台来构建控制系统.针对控制器在工程实际中的需要,上位机配置了显示、控制、通信、报警等功能模块,下位机配置了通信、A/D转换、D/A转换、CAN总线等模块,同时分析了系统的运行流程,采用多线程技术对系统功能加以实现.对系统的实际测试结果表明系统完全可以满足设计要求,并具有良好的扩展性和二次开发可行性.系统以工业注塑机为背景,实现了嵌入式技术和工业控制技术的结合.     

基于FPGA的嵌入式ZigBee网关的设计与实现

为了更好地实现物联网或工业控制领域中传感器网络设备的远程监控功能,本文设计了一种基于FPGA的嵌入式网关系统的随机方法。该设计通过构建可编程片上系统(SOPC),并利用NiosII嵌入式系统通过串口通信来实现对多个ZigBee网络的数据采集,同时结合以太网通信实现数据传输和上位机实时监控功能。整个系统在DE2-115开发板[1]上实现并通过验证,实验结果满足设计要求,并具有较好的灵活性、可配置性和应用前景。     

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).