基于1-Wire技术的无线传感器节点数据采集单元接口设计

针对无线传感器节点数据采集单元存在的接口扩展性不强的问题,设计了一种基于1-wire技术的数据采集单元接口.将多传感器直接或间接(通过接口转换器)通过1-Wire总线连接到节点的微控制器,使系统具有接口简单,节省I/O口,便于扩展和维护等优点.此外节点可装载的传感器数量增多,使网络要求的节点数减少,降低了网络的成本以及设计和维护难度.以1-Wire式温度传感器DS18820为例,介绍了1-Wire总线接口的软硬件设计方案,并给出了测试结果.设计思想和方法也适用于其他1-Wire器件,对无线传感器节点数据采集单元的接口设计具有帮助和促进作用.     

基于C51的DS18B20驱动电路设计

针对1-Wire总线器件DS18B20与单片机直接连接时单片机I/O端口驱动能力不足,存在限制传感器数量和传输距离的问题,本文设计了一种驱动电路.通过C51编程,可实现1-Wire总线数据的双向传输.在不增加单片机I/O端口资源占用的情况下,驱动电路可以接成主从方式使用,使1-Wire总线可驱动的传感器数量和传输距离有了极大提高.该电路已用于由DS18B20实现测温的粮仓测温系统中.     

基于1-Wire总线技术的远程多点温度采集系统解决方案

介绍了采用1-Wire总线技术实现远程多点温度采集系统的解决方案,讨论了基于1-wire技术的DS28EA00数字温度传感器在远程多点温度采集实现过程中的使用方法。     

1-Wire总线在精细农业数据采集中的应用

介绍了1-Wire总线在精细农业数据采集中的应用。详细介绍了1-Wire总线协议,并利用基于1-Wire总线协议的温度传感器DS18B20和C8051F330单片机实现了农作物生长环境温度分布式测量系统,给出了系统电路图和部分程序代码。     

1-Wire总线驱动电路设计

针对1-Wire总线与主控制器直接连接时主控制器I/O端口驱动能力不足,限制传感器数量和传输距离的问题,设计了一种由线驱动器及与门电路组成的驱动电路.通过简单的程序设计,即可实现1-Wire总线数据的双向传输和驱动.该驱动电路在不增加单片机资源占用的情况下,可由一路1-Wire总线分离为多路独立的总线,并完全兼容于其协议标准,使1-Wire总线可驱动的传感器数量和传输距离有了极大的提高.本电路具有结构简单、易于扩展的特点,不仅可应用于由DS18B20组成的温度测量系统中,也适用于对其它1-Wire器件的驱动,对1-Wire总线系统的设计应用具有帮助和促进作用.     

ISA总线与1-wire器件的接口设计

本文介绍了ISA总线与1-wire器件的接口设计，说明了利用微机硬件定时器实现1-wire器件时序的定时，给出了精确定时的C函数和接口的有关程序。     

1-wire测温技术皮纳卫星星载应用研究

随着皮纳卫星功能的增加以及集成化的提升,传统热敏电阻测温方法,由于其电缆走线复杂,所需电缆数量非常多的缺点,不利于皮纳卫星的集成化。本文引入了一种基于1-Wire总线的测温方法。针对空间应用的特点,分析了1-wire测温技术及其特性;通过试验,对1-wire测温芯片DS18B20进行了空间环境适应性分析,并得出了相应的结论;给出了1-wire测温技术卫星上应用的设计思路,并针对卫星可靠性要求高的特点,介绍了软硬件的故障处理方法,最后进行了在轨验证。该技术很大程度上减轻了卫星测温电缆的重量,提高了皮纳卫星的集成度,具有推广应用的前景。     

基于1-Wire技术的总线系统可靠性研究

1-Wire(单总线)技术具有的结构简单、接口方便的特点在简化1-Wire网络设计的同时也降低了系统的可靠性.在软件编程中严格遵守1-Wire通信协议是实现系统可靠运行的基本务件.通过选择合理的1-Wire网络拓扑结构、解决寄生电源问题则可以提升系统的可靠性能.1-Wire技术中的二叉树搜寻算法可以作为一种验证可靠性的方法被使用,它的正常工作通常保证了网络系统的可靠运行.     

DS18820单线多点测温系统设计

DS18820是一款改进型智能数字温度传感器,其测温范围为-55℃～＋125℃,在一10℃～＋85℃范围内测量精度为±05℃,而且测温分辨率（9～12位）可编程调整。DS18820采用了单总线（1-Wire）接口技术,     

基于FPGA的实时分布式温度采集技术

分布式温度采集系统大多采用单片机作为控制器,通过轮流读取每个监测点的温度进行温度监测.当要监测的温度点非常多时,系统显然无法实时监测每一个监测点,降低了系统的效率和实时性.本文采用FPGA作为分布式温度采集系统的控制器,并使用1-Wire器件DS18820作为监测点的温度侍感器,可以实时监测每个监测点,提高了系统的实时性和稳定性.     

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.