超声波隧道风速测量技术研究

研究了一种基于鉴相技术的超声波隧道风速测量方法,建立了风速测量模型。该方法克服了传统时差法电路复杂、信号处理较难的缺点,实现了隧道风速的高精度实时检测。测量系统采用一个传感器连续发射,两对传感器同时接收的结构实现不同风速段的测量,在保证测量范围的同时提高了低风速段的测量精度。系统以单片机ATMEGA128为核心,采用CPLD进行高精度数字鉴相,提高了处理精度;利用温度补偿技术进一步提高测量精度。与传统的测量方法相比,该系统测量精度有较大提高。     

基于ARM-Linux和CPLD的移动式风速仪设计

分析了利用超声波时差法测量风速风向的基本原理,设计了基于ARM-Linux和CPLD微处理器的移动式风速仪。给出了以S3C6410和EPM570T100C5为处理核心的超声波风速仪的设计实现方法。重点阐述了超声波驱动电路、信号调理电路、Linux移植以及系统软件的设计。测试结果表明,该系统可以实现对风的精确测量,且工作稳定可靠。     

基于ARM+CPLD的高精度超声波风速仪的设计

分析了运用超声波时差法测量风速风向的基本原理,介绍了风速风向的相关算法,重点给出了基于ARM+CPLD的超声波风速风向仪原型设计。同时提出了一种处理0°(360°)附近平均风向问题的算法,结合实际运用(风力发电)给出了一种运用气压传感器进行绝对风速测量的理论模型。所设计的超声波风速风向仪对环境监测和风力发电等具有重要的参考应用价值。     

CPLD技术在时差法超声波流量计中的应用

研究了多通道时差法超声波流量计的测量原理,介绍了流量计系统的硬件组成和实现方法,概述了软件功能和软件流程设计.采用CPLD+AVR单片机实现高精度计时、复杂逻辑控制以及采样控制和多机通讯,以提高流量计测量系统的精度和稳定性.     

风速风向的移动测量系统设计

针对传统测风仪器无法直接用于移动条件下(如车载或船载时)的风速风向测量的问题,设计了一种可以在移动平台上应用的超声波风速风向测量系统。该系统使用超声波时差法测量平面内二维风向风速,同时使用霍尔传感器和电子罗盘测量基座的移动速度和方向,通过微处理器对测得的风速风向进行修正,得到实际风速和风向。系统采用ARM作为核心控制器,提高了时差的测量精度,并降低了功耗。     

基于STM32的风速监测系统设计

为了准确掌握气象动态,实时可靠获得风速信息,设计了基于STM32微控制器的风速监测系统。该系统采用三杯式风速传感器作为传感设备,STM32芯片作为主控制器,SP3485收发器和HAC-UM数传模块作为通信传输模块。给出了基于STM32风速测量技术、硬件设计的总体框架以及系统软件实现方法。通过STM32定时器捕获脉冲频率,实现了对风速实时准确的监测。经测试,该系统具有功耗低、性能稳定、测量精度高、功能扩展方便等特点。     

CPLD技术在时差法超声波流量计中的应用

研究了多通道时差法超声波流量计的测量原理,介绍了流量计系统的硬件组成和实现方法,概述了软件功能和软件流程设计。采用CPLD AVR单片机实现高精度计时、复杂逻辑控制以及采样控制和多机通讯,以提高流量计测量系统的精度和稳定性。     

超声波风速风向仪的研制

超声波风速风向的设计仪国内少有报道.本系统采用时差法原理实现对风速风向的测量,利用单片机PIC18F4580为控制核心,构成高速计时模块,利用多重阈值比较电路,结合软件设计实现发射时间范围控制和可靠性检验.实验结果表明系统在风速30m/s以下与参照曲线拟合程度较高,实现了用时差法超声波测量风速风向的目的,具有一定实用价值.     

基于STM32F的超声波风速风向仪设计

为提高风电机组的发电效率及降低作业事故,针对风电机组的风速参数控制要求给出了基于STM32F系列处理器实现的超声波风速风向仪测量系统.该仪器运用超声波时差算法测量风速风向,简化了信号处理部分的硬件设计,经有效的软件滤波平滑算法并通过风洞标定后,获得较高精度和稳定性.设计的超声波风速风向仪在气象监测和风力发电机组的运行控制等应用方面具有实际使用价值.     

风洞超声波风速风向三维测量装置设计与实现

超声波在顺逆风中传播速度不同,在距离一定的条件下,风在顺逆向传播存在时差,将超声波传感器按一定阵列布置,基于空间向量分析算法可以设计一种超声波三维风速风向测量装置。详细介绍了风速风向三维测量装置正三棱锥体传感器布置方案,阐述了硬件电路的总体框架图和各外围接口电路的设计,说明了超声波风速风向测量装置算法软件编程实现和计算控制流程。通过对装置主要功能模块的测试和实际风洞试验证明,超声波三维风速风向测量装置能够实时测量风速的大小和方向,满足风洞试验测试要求。     

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.