基于AT89C52的非分散红外测油仪的研制

本文介绍了非分散红外光度法原理,设计了一种基于AT89C52单片机的非分散红外测油仪.仪器采用了高精度的光源调制技术.相敏检测技术等弱信号提取技术,单片机系统全部采用新型12C或SPI集成电路芯片设计,具有测量精度高、体积小、功耗低等特点,适用于水中矿物油和动植物油含量的检测.     

基于蓝牙传输的脉搏血氧饱和度监测系统设计

血氧饱和度的测量在临床和日常保健中有重大意义。系统是以AT89C51单片机为核心控制的测量仪,实现了使用光传感器采集红光和红外光透过动脉血管后产生的信号电路以及相关的测量电路,并利用单片机控制蓝牙模块,采用基于HCI层的单片机对蓝牙模块的控制方式,实现了与PC机的通信。本文把血氧饱和度检测系统和蓝牙技术结合起来,克服了使用传统的有线系统及病人不能自由活动的缺点,给病人带来了行动上的便利,也给家庭监护、远程医疗等创造了条件。     

基于MSP430单片机控制的近红外光谱仪用光源

在使用近红外光谱仪器对农产品成分的含量进行测量时,光源的稳定性对测试结果非常重要.介绍了一种使用单片机控制的光源稳定系统,它通过AD采集反馈电压,运用数字PID算法,通过控制DA输出来调整NMOS场效应管的导通情况,从而达到稳定卤素灯工作电流的目的.该光源系统工作稳定可靠,控制精度优于0.02%,可作为近红外光谱仪专用光源.     

基于植物专家系统的智能LED光照控制系统设计

光照度是植物生长的重要环境因素。目前,我国植物工厂的光照控制大多使用基于传统光源的简单控制模式;即使少数使用了LED光源的系统,也只是采用了定波长、定光强的LED光源。为提供适合植物生长的光环境,设计了基于植物专家系统的智能LED光照控制系统。该系统采用红、蓝和远红外3色光LED组成的发光模块控制光照。植物专家依据不同生长期植物对光谱的选择性吸收特点,设定各色光在各生长期的光照度;以单片机为核心的控制系统实时检测环境光照度,并与专家设定值进行比较,计算实际调光量;由脉宽调制(PWM)信号控制发光模块各色光光照度。控制系统具有光照度超限报警及温湿度自动控制的功能,既可以实现光环境的自动控制,也可以根据用户需要灵活调控,具有操作简便、控制精确、能源利用率高的特点。     

基于单片机的视觉检测光源控制器

为确保视觉检测的准确度,高性能的光源控制器是机器视觉系统不可或缺的关键组件。基于单片机控制技术,本人设计了一款高性能LED光源控制器,该系统采用了8位的STC12C5410AD芯片,利用RS232进行实时数据传输,以完成单片机对输出电流的实时检测和实时控制。该控制器运行可靠,能实现精确识别,已实现量产。     

七彩LED光源控制方案设计

本文介绍了一种采用单片机实现七彩LED光源控制的设计方案。单片机采用带PWM输出端口的AD型单片机,通过控制PWM（脉冲宽度调制）的占空比实现对R（红）、G（绿）、B（蓝）三色LED光源的光强度数字化调控,通过控制LED的R、G、B三色驱动和显示实现多彩的组合光调制,从而实现七彩效果的LED光源控制技术。     

基于NDIR的水中污染油检测系统的研究

油类物质(石油类物质和动植物油)作为水和土壤中的一种重要的污染源,不仅使水质不断地恶化,而且给人类的身体健康带来极大的危害.本文时非分散红外光度法(NDIR)测油仪的测油原理和内部结构进行了详细地理论分析.利用此仪器,可以检测出水中矿物油和动植物油的污染物含量,还可用于有机试剂纯度检测及含各种不同C-H键有机物总量和分量的测量.此测油仪采用了调节方便、频率精确的光源调制系统和相关检测技术,具有较高的灵敏度和稳定性,并且体积小适于野外现场使用.     

单片机控制自动付油系统的设计

叙述了采用单片机控制的自动付油系统,通过使用高性能的密度传感器,保证了系统的高精度计量。本文还介绍了控制系统电路的设计方法。     

半导体激光针灸治疗仪的研制

介绍由单片机控制的使用半导体激光器作照射光源的针灸治疗仪的软硬件设计。该仪器在使用中可实现光功率、温度及时间的控制。另外简要介绍了光纤输出系统的光学设计     

一种医用输液滴速自动控制与报警系统

针对传统输液依靠人工控制和监视的问题,研制了一种医用输液滴速自动控制与报警系统。该系统以MCS-51单片机为控制核心,采用红外光电式传感器对点滴速度进行检测,通过步进电机控制松紧机构自动调整点滴速度,实时显示输液信息并进行声光报警。经临床应用结果表明,该系统具有检测准确,响应速度快,安全可靠等优点。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.