排爆机器人手动控制信息采集系统的实现

排爆机器人手动控制信息采集系统主要由PC机、手动信息采集板,外围传感设备组成。手动信息采集板以AT89C51单片机和12位并行A/D转换器AD574A为核心,实现多路A/D采样,完成手动控制信息的采集;PC机与手动信息采集板采用RS232通信建立联系,在中断方式下通过C语言编程实现采样数据的接收。     

基于C8051F单片机信号发生器设计与应用

信号发生器设计以C8051F121单片机为核心,采用串口通信和D/A转换,通过在VB可视化操作界面下参数化调节信号的幅值、脉宽、频率、持续时间,可以得到任意波形.数据通过串口传给单片机,单片机经过锁存器将数据保存在外部存储器中,通过控制电路启动D/A转换产生模拟信号.然后可以作为弹加速度测试装置的输入信号,来验证实际弹侵彻的过载曲线.     

一种在单片机系统中利用D／A转换器实现D／A和A／D转换的方法

一引言在单片机的开发与应用中,经常遇到D/A转换和A/D转换的问题,一般的方法是将单片机分別与D/A转换器及A/D转换器相连。在本文所介绍的单片机系统中,采用了一片D/A转换器分时地实现D/A转换器和A/D转换,这一     

简易液位控制系统

本设计以AT89S52单片机为核心,采用A/D转换器ADC0832把模拟信号转化成数字信号输入单片机,得到液位信息,再通过单片机显示高度和重量、判断液位,进行放水或注水等操作。本系统由测液位传感器、电压跟随器、A/D转换器、电磁阀控制、输入输出等五部分构成,可实时显示当前液位高度和瓶内液体重量,以     

电动天窗耐久性测试系统的研制与开发

提出了一种基于VB串口通信的电动天窗耐久性测试系统的软硬件实现方案.该系统包括PC机构成的上位机和单片机构成的下位机.上位机提供了良好的人机交互界面;下位机采用集成电路,以及信号采样、V/F、F/V转换和D/A转换,通过串口通信将单片机与PC机连接.借助这一系统,可方便灵活精确地实现对各种电动天窗的耐久性测试.     

自动开伞器真空膜盒特性测试系统设计与实现

真空膜盒作为自动开伞器的核心部件,性能可靠与否直接关系到跳伞人员的生命安全。为了实现膜盒特性的准确检测,设计了基于单片机控制的自动测试系统。测试系统包括测试箱模块、位移测试模块、压力测试模块以及单片机控制模块,在合理选用传感器、A/D转换器、单片机、显示器等硬件的基础上,分别对各功能模块进行了具体设计。     

来稿摘登

<正> 微机料位巡回检测系统的设计以8098为控制核心,采用重锤式机械传感器构成固体料位多点巡回检测系统.系统由控制器、分选器和发信器构成.控制器完成发布检测命令,接收传感器发回的脉冲码,并进行数据处理,显示打印有关数据,包括仓号、料位高度和重量,并能完成与PC机的通讯;分选器用来接收控制器发出的控制信号,选通指定的发信器;发信器即传感器,每被分选器选通一次,完成一次检测工作,即向控制器发出对应于空仓高度的脉冲码.文章给出了硬件原理图,阐述了检测过程,并给出了软件流程图.空军长春飞行学院(130022)孙国春 王立志单片机三斜率积分型模数转换介绍用单片机控制三斜率积分型A/D的方法.可实现用较小的时间,获得128倍的分辨率.在积分型A/D转换中,分辨率和转换时间是相互矛盾的.用单片机控制三斜率积分的方法进行模数转换,可以较好的解决这个问题.其工作原理为:先用固定时间t_1以斜率y_1对模拟电压Vx进行正向快速积分.然后以斜率y_2对参考电压—E进行反向快速积     

基于单片机的室内甲醛测试仪

简要阐述利用单片机、甲醛传感器、I/U转换器RCV420、5G14433A/D转换器等实现室内甲醛测试系统.     

汽车减震器参数同步数据采集系统设计

为了解决汽车减震器运行时压力与位移信号难以同步采集的问题,设计了一种基于51单片机和AD7572的同步数据采集系统.系统通过51单片机控制两个独立的高速A/D转换通道同步采集压力与位移信号,采用USB串口与上位机通信实现数据的储存、传输和处理.示功图对比表明,该系统可以完成减震器关键参数的同步采集,具有较高的实用价值.     

基于LabVIEW的阀门摩擦测试系统设计

根据阀门摩擦阻尼特性参数的测试要求,设计了基于LabVIEW的摩擦测试系统.进行了测试系统的工业控制计算机、电机驱动以及数据采集的硬件设计,采用LabVIEW实现RS232串口通信、A/D数据采集以及D/A数据输出等模块.     

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.