基于MSP430F149的便携式超声波测距仪设计

根据超声波测距原理,设计了一种基于MSP430F149的便携式超声波测距仪;详细介绍了该测距仪硬件电路的设计,并给出了该测距仪软件主程序流程。测试结果表明,该测距仪运行稳定、性能可靠,测量精度可达2 mm。     

高准确度超声波测距仪的研制

利用超声波传感器实现无接触式测距。系统由AT89C2051单片机、超声波发射电路、超声波接收放大电路、环境温度采集电路及显示电路组成。超声波测距仪具有高集成度、响应速度快,测量准确度高(±0.02m)、性能价格比高等特点。     

基于单片机的超声波测距仪设计

本设计是以AT89S52单片机为核心的数字显示超声波测距仪的硬件电路和软件设计方法。整个电路采用模块化设计,由主程序、预置子程序、发射子程序、接收子程序、显示子程序等模块组成。各探头的信号经单片机综合分析处理,实现超声波测距仪的各种功能。     

一种高性价比的超声波测距仪设计

本文详细介绍了一种高性价比的超声波测距仪的设计方法。该测距仪仅使用NE555电路、两级放大电路、电平比较电路和单片机，即能实现超声波的发射与接收。单片机为该测距仪的核心单元，用于发射电路的控制和接收数据的处理。本系统在5-200cm的距离内测量精度可达±0．5cm，并且易于调试，成本低廉，具有较高的实用价值和良好的市场前景。     

高精度低成本车用超声波传感器的研制

本文介绍了利用超声波传感器实现无接触式测距.系统由AT89C2051单片机、超声波电路、环境温度电路及显示电路组成.该测距仪具有高精度(±1 mm)、低成本的特点.     

超声波测距在汽车倒车防撞系统中的应用

由于超声波指向性强，能量消耗缓慢，在介质中传播的距离较远，因而超声波经常用于距离的测量，如测距仪和物啦测量仪等都可以通过超声波来实现。本文主要介绍超声波在汽车倒车防撞报警系统中的应用，以AT89C51单片机为核心的低成本、高精度、微型化数字显示超声波测距仪的硬件电路和软件设计方法。     

ATmega16的语音型超声波测距仪的设计

介绍一种以单片机ATmega16为核心的超声波测距仪。该测距仪利用单片机ATmega16的输入捕获功能,测量超声波从发射探头发射至接收探头接收所经过的时间;采用DS18820测量环境温度,补偿温度的变化对超声波传播速度的影响,提高测量精度;利用语音芯片ISD4004播报测量结果等语音信息。给出了测距仪的关键硬件电路、测量时间的输入捕获中断子程序和录音／放音子程序。测试结果表明,该测距仪测量精度高,语音播报清晰、流畅。     

数字式超声波测距仪设计

介绍了一种基于单片机的数字式超声波测距仪的设计。详细地说明了单片机和外围电路、超声波传感器、温度检测电路、显示电路等硬件设计以及主程序、测温子程序等的软件设计方面。设计中使用已封装好的超声波模块,方便简单。同时考虑了环境温度的改变对超声波速度的影响,提高了测量精度。此超声波测距的实验运行良好,具有操作简单,性能稳定,精度高,体积小的优点,可用于多种场合,符合未来的发展方向。     

基于单片机AT89S52的超声波测距系统的设计

介绍了基于AT89S52单片机为主控件的超声波测距仪的工作原理、硬件和软件的设计。硬件主要由超声波发射、接收检测电路和显示电路组成。该系统测量精度高．能够清晰地显示测量结果,可应用于汽车倒车雷达、建筑施工工地以及一些工业现场的位置监控,也可用于如液位、井深、管道长度的测量等场合。     

基于ATmega8单片机的超声波测距仪

利用超声波测量距离是一种有效的非接触式测距方法;基于ATmeg嘏单片机的超声波测距仪采用渡越时间法进行超声波掣距,介绍了其硬件及软件设计方案,并对其由温度变化带来的误差进行了补偿;该测距仪比其它单片机控制的超声波测距仪具有更高的性价比,可广泛应用于各种需要测量距离或物位参数的场合。     

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.