单光纤光栅实现位移、温度同时区分测量

结合光纤光栅悬臂梁调谐的特点,采用悬臂梁矩形梁结构,将光纤光栅粘贴在悬臂梁侧面,利用反射波的带宽对应变敏感而对温度不敏感的特性解调悬臂梁自由端的垂直位移,和反射波的中心波长对温度敏感而对应变不敏感的特性解调温度,成功地实现了对位移和温度的同时测量.基于光谱分析仪0.1 nm的光谱分辨率,实验可得到位移、温度同时区分测量系统的带宽随位移变化的灵敏度为0.153 nm/mm,位移分辨率为0.193 mm,位移测量范围可达6.15 mm;中心波长随温度变化的灵敏度为0.029 nm/℃,温度分辨率为3.4℃,温度测量范围为45℃.实验结果与理论分析基本一致.     

分布式光纤温度传感器在稠油开采中的应用

为了满足稠油油井安全生产和温度监测的需求,设计了一种传感距离为2 km的分布式光纤温度传感器用于监测稠油油井的温度信息.同时对分布式光纤温度传感器进行了特性分析,并给出了高温温度实验结果.实验结果显示:分布式光纤温度传感器能够在稠油油井温度测量方面进行很好的应用.系统温度范围为0～350℃,测温光纤长为2 km,测量温度精度为±1℃,空间分辨率为1m,为油井井下温度测量提供了科学依据.     

高精度分体式超声波温度测量仪研究

传统的温度测量仪在较宽的测量范围内无法保证稳定的高精度测量,针对此种不足,设计了一种高精度分体式多声道超声波温度测量仪.该温度测量仪利用超声波测温技术,以被测物体作为传播媒介,在传播距离确定的条件下,通过测得超声波在介质中的传播时间间接测得介质的温度.分体式多声道的结构设计使温度测量准确有效,同时降低了传感器材质在耐高温、耐腐蚀方面的限制要求.基于FPGA的快速处理电路以及细分插补算法,使传播时间的测量分辨率优于纳秒级,确保实现分辨率优于0.001℃的高精度温度测量.     

基于热电效应的热流传感器设计

基于金属的热电效应和热传导原理,经过理论分析计算,设计了一种高量程的热流传感器,并通过机加工艺、焊接工艺及涂敷工艺实现了热流传感器制作.性能测试与数据处理结果表明:该传感器输出信号与热流近似成正比,热流测量范围为0～3 000 kW/m2,测量精度优于±4%FS,耐辐射温度达1700℃.     

基于ZigBee无线传输的倾角传感器网络

应用ZigBee传感器节点的硬件和软件以及上位机软件研制了一种无线倾角传感器网络系统.采用了二次温度补偿解决温度对测量精度的影响,并对无线网络的功耗进行了优化处理.实验表明:该系统的测量精度达到了±0.01°(倾角测量范围为±3 °),数据采集间隔为1次/s时,平均电流仅为0.21 mA,达到了高精度低功耗的设计要求.     

基于MLX90614的无线温度采集系统设计

在医疗设备研发制造等领域,为了实现人体体温附近范围内高精度的温度测量,设计了一种基于低功耗单片机MSP430、非接触式红外温度传感器MLX90614以及蓝牙传输技术的无线温度监控系统,采集发送模块以超低功耗单片机MSP430为控制核心,通过SMBus协议读取MLX90614所采集到的目标温度值,利用蓝牙透传模块将数据上传.MSP430单片机的使用极大地降低了系统功耗,MLX90614非接触测量方式满足了医疗设备研发污染隔离的特殊需求,具有较高的测量分辨率和精度,蓝牙透传模块的使用使得系统易于实现数字化、网络化和集散化管理.实验表明:该系统在32 ～42℃温度范围内,测量精度达±0.2℃,并实现了测量结果的无线传输,在医疗设备研制领域有广泛的应用前景.     

基于AT89C2051单片机的大气温度采集和记录系统

系统以AT89C2051单片机为核心,能对大气温度进行定时测量.测量范围为-55℃～+125℃,精度最高可达0.0625℃,并可存储256个温度数据.系统还提供了能与PC机进行通讯的RS232接口.     

新闻之窗

▲WFHS-40型数字红外辐射温度计研制成功上海工业自动化仪表研究所已研制成WFHS-40型数字红外辐射温度计。该温度计具有数字显示和模拟信号输出、应用量程宽、分辨率高、可以在线安装使用和携带使用等特点。它是低温测量领域中的一种新型辐射测温仪表。仪表主要技术指标是:测温范围:基型-20～ 100℃(可分档扩展到 500℃);工作波段:8～14μm;示值基本误差:基型不大于±2℃±1字,其它范围不大于±1%±1字;示值显示分辨率:基型为0.1℃,其它范围为1℃;响应时间小于1秒;距离系数为16;模拟量输出信号:基型为-2.0～ 10.0mv,其他量程满度为10mv。该温度计可广     

一种光纤荧光光谱测温方法的研究

基于光纤荧光的测温机理介绍了一种温度测量系统的构成。系统采用Cr3+:YAG晶体作为荧光材料,蓝色发光二极管激励光源。经光纤将荧光信号输出,输出频率被输入到单片机系统中,单片机计算出荧光寿命,进而得到目标温度值。该系统对温度的测量具有准确度高、抗电磁干扰、分辨率高等特点,并且可以结合相关计算机技术和数据采集单片机系统实现通讯控制,操作简单,可以及时测量并存储数据,提高了系统的智能化。利用该装置通过检测荧光物质寿命实现了高精度温度测量,其误差小于±5℃。     

低成本高分辨率电化学传感技术测量大气N_O

为解决三电极电化学传感器分辨率过低、光学探测仪器成本高昂的困扰,设计了以STM32为核心的NO_2电化学传感器监测系统,利用低成本高分辨率电化学传感技术测量大气中NO_2的体积分数。实验表明:-10～10℃时传感器响应时间T90受温度影响严重,传感器灵敏度温度特性曲线S (T)=0. 197 60+0. 002 13T-0. 001 21T2(-10℃相似文献   

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.