电缆管道巡检机器人嵌入式系统的设计与实现

针对电缆管道巡检机器人的任务需求,提出了一种基于DM6446的嵌入式测控系统.从硬件和软件两方面详细介绍了嵌入式系统的设计和实现方法.硬件上采用以高集成度的DM6446双核处理器为中心的模块化设计;软件开发中基于Linux的层次化架构和多进程/多线程管理实现了运动控制、视频采集、参数检测、网络传输等功能.达芬奇技术的应用和实现保障了机器人实时视频编码和视频数据的传输.各种测试结果表明了嵌入式系统设计的合理性,整体机器人实现了各项功能技术要求.     

基于DM6446的视频运动车辆检测系统

给出了一种基于DM6446处理器的视频运动车辆检测系统的技术实现方法,介绍了系统的硬件结构及软件设计思路。结合DM6446双核处理器的特点,给出了处理器ARM端与DSP端通信及双缓冲区切换的具体方法。在视频运动车辆检测算法上,采用差异积累法对DM6446实时获取的交通视频数据进行背景建模,用背景差法检测车辆运动区域,再结合Otsu阈值化、形态学滤波及区域生长等算法,最终在DM6446硬件平台上实现视频运动车辆的实时检测。实验结果表明,该系统具有良好检测效果。     

基于DM6446的视频运动车辆检测系统①

给出了一种基于DM6446处理器的视频运动车辆检测系统的技术实现方法,介绍了系统的硬件结构及软件设计思路。结合DM6446双核处理器的特点,给出了处理器ARM端与DSP端通信及双缓冲区切换的具体方法。在视频运动车辆检测算法上,采用差异积累法对DM6446实时获取的交通视频数据进行背景建模,用背景差法检测车辆运动区域,再结合Otsu阈值化、形态学滤波及区域生长等算法,最终在DM6446硬件平台上实现视频运动车辆的实时检测。实验结果表明,该系统具有良好检测效果。     

嵌入式人脸识别器的GUI设计

Qt/embedded是图形化界面开发工具的嵌入式版本,整体采用面向对象编程,拥有较高的运行效率和良好的体系架构和编程模式。达芬奇技术是基于DSP的数字音视频优化的系统解决方案,它在嵌入式操作系统方面对Linux的支持极为完善,可以实现复杂GUI系统的设计。利用qt/embedded和达芬奇技术完成了人脸识别器的图形用户界面设计,实现了人脸检测结果显示,人脸数据的修改和更新功能。另外成功实现了qt/embedded在DM6446上的移植,并有效使用了DM6446的视频处理前端和视频处理后端实现视频采集和显示。     

嵌入式宽带可视电话系统设计及实现

设计及实现了一款基于美国德州仪器公司(TI)TMS320DM6446平台的嵌入式宽带可视电话系统.该嵌入式宽带可视电话系统以TMS320DM6446处理器为核心,提高了可扩展性和平台独立性,通过MSP430子系统等解决了处理器I/O资源有限和降低了对外围低速模块实时控制的复杂度,通过myOPAL的实现提高了本系统的性能和并发处理能力,降低了延时等,实现了视音频双向实时通信.     

LED/LCD视频拼接器的多视频源系统设计

为了在大尺寸LED/LCD拼接显示系统中实现多视频源灵活接入、显示窗口管理等功能,设计了基于32位嵌入式处理器、专用视频交换芯片和大规模FPGA硬件平台的视频拼接处理器,提出了拼接处理器各个模块软硬件的设计思路.按照这种思路设计的LED/LCD拼接处理器产品已经在行业中取得了良好的口碑,获得了良好的经济效益.     

基于DSP的嵌入式Linux内核移植的研究与实现

为了提升嵌入式系统的开发效率,提出了一种向嵌入式平台上移植操作系统的方案。硬件平台以TMS320DM6446处理器为例,操作系统以嵌入式LINUX操作系统为例。首先,分析了软硬件平台结构。然后,实现了嵌入式Linux内核在TMS320DM6446上的移植。移植的主要内容为:交叉开发环境的建立、内核的移植,最后,将编译好的内核代码通过已经移植好的BootLoader下载到开发板上,Linux内核就成功的移植到了TMS320DM6446处理器中。     

嵌入式宽带可视电话系统设计及实现

设计及实现了一款基于美国德州仪器公司（TI）TMS320DM6446平台的嵌入式宽带可视电话系统。该嵌入式宽带可视电话系统以TMS320DM6446处理器为核心,提高了可扩展性和平台独立性,通过MSP430子系统等解决了处理器I／O资源有限和降低了对外围低速模块实时控制的复杂度,通过myOPAL的实现提高了本系统的性能和并发处理能力,降低了延时等,实现了视音频双向实时通信。     

达芬奇平台下的运动目标检测算法的应用研究

本文介绍一种适用于TI推出的达芬奇双核(ARM+DSP)处理芯片TMS320DM6446的运动目标检测算法。首先通过对算法进行仿真实验验证算法的可行性,在验证算法可行性之后,以TMS320DM6446作为核心处理器,基于codec engine机制实现了检测算法封装和移植,并在此基础上进行了一定程度的算法的优化以提高算法的效率。测试结果表明,对于720x576大小的视频序列,本文的运动目标检测算法是可行的,在TMS320DM6446平台上运行可以达到10fps左右,为进一步实现智能视频分析的嵌入式产品积累了丰富的经验。     

嵌入式Linux的BootLoader在DM6446上的实现

移植引导装载程序(BootLoader)是嵌入式系统开发的关键技术.介绍了BootLoader的特点及其在DM6446平台上的引导方式,分析U-Boot源代码的运行机制,并对U-Boot代码进行修改和调试,最后总结出移植BootLoader的成功经验,详细阐述了U-Boot在DM6446平台上的移植步骤和关键技术.这对DM6446双核处理器上的产品开发有一定的借鉴作用.     

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).