AD7711与单片机AT89S8252的接口技术

介绍一种高分辨率的双路A，D转换器AD7711，能满足双路A/D采样要求。内容包括AD7711的特点，内部寄存器结构和外部接口，并详细阐述了数据采集系统中AD7711与单片机AT89S8252的接口技术，包括硬件接口电路和软件程序设计及其注意事项。     

交流采样技术及其DSP实现方法

本文提出了对电力系统参数进行交流采样的设计思想．结合实例介绍以TMS320C240DSP与高速14位A／D转换器AD7863构成的数据采集系统，给出了采样算法、硬件电路及软件流程等。     

高精度两次采样AD转换

AD转换是测量中一个非常重要的部分,为了达到精度比较高的转换效果,人们往往选择位数较高的AD转换器.这样容易造成电路的成本过高.本文就介绍一种如何利用普通的AD转换器来实现高精度的AD转换.它利用两次采样的原理.通过一个模拟量进行两次转换,从而实现高精度.此转换器所需元件比较简单.主要由一个凌阳SPCE061A单片机和一些普通的选通、运放电路组成,文章从硬件电路的组成和软件程序的编写两个方面来进行说明,清晰的介绍了如何来实现高精度转换的功能.     

高精度A/D转换器AD7864与DSP接口设计与实现

详细介绍了高精度4通道同步采样A/D转换器AD7864的特点和工作方式,以及AD7864与DSP外部存储器接口进行异步数据通信的控制方法。给出AD7864与TMS320C6711的接口电路,详细介绍了工作过程,最后给出了AD7864与TMS320C6711接口软件编程实现。     

PC机与单片机接口技术的研究

本文设计了高速数据采样扫描接口电路。介绍了采用ISA卡形式以两片双端口RAM为信箱实现单片机与PC机高速通讯的接口电路和具有较高的转换速度的A／D转换器AD1674，并给出了这种器件与微机的接口设计方法。解决了传统的串、并口进行数据传输时所带来的速率低的问题，实现了高速、高精度数据采样及扫描，最后给出了相应的软件设计方案。     

一种利用光调制器的新型A/D转换器

本文介绍一种新型光AD转换器,它只用一个EO(electrooptic)光调制器。这种装置包括一个正向偏压二极管电路,此电路起增强从电一光调制器来的检测信号,重复及改善波形的作用。我们制造出一个包含LiTaO_3调制器和二极管电路的3位AD转换器。称为混合型A/D转换器。     

可编程高速采集卡的设计

本文介绍了一种可编程采集卡的设计方法，能够随意切换模拟开关，使AD转换器对多通道模拟信号进行任意采样，从而实现采集系统可灵活编程。本文通过分析传统的多通道模拟信号的采集系统电路的特点,介绍了多通道可编程采集卡的总体设计方案及其原理，并详细描述了各个模块之间的状态关系和工作时序。     

TMS320F2812的多通道高速同步交流采样设计

在电力运行参数测控类应用系统中,采用AD73360型A／D转换器采集多路电压和电流信号,使用TMS320F2812实现了高速同步采样及电力参数在时域的计算;给出AD73360和TMS320F2812的硬件接口电路;采样系统采用C语言编程,给出了主程序、多通道缓冲串行接口初始化过程等的流程图;论述了采样接收中断、时域采样数据处理等技术。通过测试验证了设计方案的适用性和正确性。     

过采样技术在智能电气阀门定位器中的应用

在智能阀门定位器设计中,AD转换器的精度对智能电气阀门定位器控制精度具有重要影响.文章基于瑞萨单片机,采用过采样技术将10位AD转换器的精度提高到12位,提高阀门定位器控制精度的同时,避免采用昂贵的片外AD转换器,降低产品成本.     

煤自燃倾向性的氧化动力学测定中温度测量电路设计

在煤自燃倾向性的氧化动力学测定过程中需要对温度进行高精度的测量并记录。为了满足测温要求,选用高分辨率AD转换器AD7714及三线制Pt100热电阻作为温度传感器构建了温度测量电路;为解决器件非线性度引起的输入、输出为非严格线性关系的问题,采用分段线性插值方法对输出值进行插值运算。实验结果表明,该温度测量电路的AD采样分辨率为0.006 7℃,满足设计要求,且实验数据具有很高的稳定性和可重复性。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

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。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

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.