基于ADS7812的数据采集系统设计

现代信息采集系统中A/D转换是关键,本文介绍了利用ADS7812进行A/D转换的数据采集系统。文中对ADS7812的特性进行了分析,给出了ADS7812与51单片机接口的程序代码,最后提出应用ADS7812应注意的一些问题。     

基于I2C总线的模/数转换器ADS1100

ADS1100是基于总线的具有自校准功能的16位精密A/D转换器,具有体积小、接口简单、功耗低、比例放大等优点.它以电源电压作为参考电压,有单次和连续两种数据转换模式,能直接测量小信号,是高分辨率采样测量电路的理想A/D转换芯片,具有良好的应用前景.本文介绍了模/数(A/D)转换器ADS1100芯片的主要特点、引脚、内部结构、工作原理,并提供了ADS1100读写操作的程序代码、典型硬件连接电路和应用实例,最后给出了使用中要注意的问题.     

基于PIC单片机的PON光功率计的设计

介绍了一种基于PIC单片机光功率计的设计.该光功率计不但能实现普通光功率的测量需求,并通过特殊设计的光路和电路结构来实现PON系统中对信号光功率测试的特殊要求,即要满足线路上3种光信号波长的同时测试、在线测试和1310 nm信号的突发测试功能,从而大大方便PON系统的安装、管理和维护.该功率计电源电路设计成软开关,实现了仪表的智能化控制.利用PIC16F877A外接的ADS1110 A/D转换芯片实现了A/D转换.PIC单片机低功耗的特性,使整个仪表功耗极低,符合手持式仪表的特点.     

基于ADS8364与USB接口的高速数据采集系统

本文介绍了高速数据采集系统的设计,该设计根据高速A/D转换器ADS8364的时序,采用FPGA硬件直接控制高速A/D转换器的数据转换和输出,并在单片机AT89S52的控制下,将转换数据通过专用USB接口模块PDIUSBD12,传送给上位PC机,文中详细叙述了ADS8364和USB接口模块的运用模式和具体硬件连接方式,介绍了系统的信号流程,以及主要软件模块设计。     

基于USB总线的多通道数据采集系统设计

介绍了以FPGA为控制核心、以USB2.0为数据接口的多通道数据采集系统,通过对模/数转换器件(ADS8365)的控制完成4路信号的采集。系统包括信号调理模块、模/数转换模块、FPGA控制模块、数据缓存模块和USB接口模块。系统的A/D转换精度为16 bit,采样率为27 kHz,保证了数据采集的准确性和实时性。此外,系统还具有一定容量的FIFO数据缓存,方便与其他系统进行数据交换。     

基于DSP和ADS8364的高速数据采集处理系统

开发了基于DSP和ADS8364的高速数据采集处理系统。该系统主要由信号调理模块、A/D转换模块、DSP处理器模块、CPLD逻辑控制模块和USB2.0通信模块组成。它能够在板卡上实现信号的采集及前端处理,并能通过USB总线与上位机通信,实现数据的存储、后端处理及显示。参考了虚拟仪器的设计思想,重点阐述了系统原理及硬件、软件的设计。     

基于ADS8364的数据采集系统设计

开发了基于DSP和ADS8364的数据采集处理系统。该系统主要由信号调理模块、A/D转换模块、DSP处理器模块、CPLD逻辑控制模块、Flash存储器模块和CAN总线通信模块组成。它能够在板卡上实现信号的采集、前端处理和存储,并能通过CAN总线与上位机通信,实现数据的存储、后端处理及在PC104上显示。     

基于混沌电路的模拟式阵列触觉传感器A öD 转换电路

本文利用混沌帐篷映射电路对小信号敏感及非线性变换的独特性能 ,提出了一种新颖的适用于模拟式阵列触觉传感器的 A / D转换电路 ,具有调理放大和 A/ D转换功能一体化优点 ,并且电路简单、易于集成实现 ,可实现多路触觉信号的同时采样和 A / D转换     

基于C8051F340的EEG信号采集系统的设计

介绍一种基于C8051F340单片机的EEG信号采集系统。该设计采用高速、高集成度的C8051F340单片机控制A/D转换器ADS8344和无线收发器ADF7020实现了EEG信号数字采集和无线数据传输;同时采用了C8051F340内嵌USB功能控制器解决接收器与计算机之间USB数据传输等问题。测试结果表明,该EEG信号数字采集系统具有集成度高、功耗低、体积小和操作方便等特点,具有良好的应用前景。     

数字化超声探伤仪中超声信号高速采集技术

探讨了数字式超声探伤仪设计中一种对超声信号进行高速采集技术。根据超声回波信号重复性的特点,利用一只高速A/D(60MHz)转换芯片在N组特定时序信号的控制下对超声回波信号进行采集,并在CPLD(复杂可编程逻辑器件)的控制下实现高速数据缓冲存储,再利用相位合成技术对转换后的N组数据进行数据合成与波形重建,从而实现了数倍于A/D转换芯片速率的高速数据采集,达到等效A/D转换速率N×60MHz。该方案成本低,可靠性高,尤其适合于高速、高准确度的超声无损检测系统中。     

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.     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.     

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.     

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.     

Call for papers Special issue on Modeling and control technologies for civil,energy,and power systems

正The control of civil,energy,and power systems presents significant new challenges for modeling and control theory.The purpose of this special issue is to provide a forum for researchers and practical engineers to discuss the recent advances in modeling and control technology development for civil,energy,and power systems.Prospective authors are invited to submit their original contributions with the focus on theory or applications of modeling,control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate and promote academic exchange between Chinese and foreign scientists everywhere.