基于AD633模拟鉴相的Q表设计

为解决万用表无法测量Q、D等参数的问题,设计了基于A1D633模拟鉴相的Q表.该测量仪采用DDS芯片AD9851产生正弦激励信号和基准信号,利用高集成度模拟乘法器AD633对信号进行模拟鉴相,并采用差分转换器AD8138对鉴相输出信号进行单端转差分变换,由C8051F060内部自带的ADC对差分信号进行模数转换和数据处理.Q表具有多量程自动切换和LCD实时显示等功能,且体积小、成本低,能满足工程、教学科研测量的需要.     

一种新型铂热电阻数字测温电路

本文介绍了一种采用连续式非线性A/D转换法进行线性化的新型铂热电阻数字测温仪,在—200℃至 650℃<的温度范围内,线性化误差仅为0.058%,采用了有源电桥和四线制等技术,使引线电阻对测量精确度的影响可忽略不计,并消除了基准电压对测量误差的影响。     

基于Cu50的精确温度测量系统

在基于热电阻的温度测量过程中,由于元器件差异和漂移的影响,会大大降低温度测量准确度;针对这一问题,提出了一种自校正技术的4电阻测量法,通过比较4组测量信号的相对大小来求得被测热电阻的电阻值,进而计算出温度值;该方法的优点是可以抵消测量电路中漂移和元器件差异的影响,从而实现在不同的温度环境下的高精度的温度测量;通过计量炉的实测的数据比较,测量误差小于0.063℃,表明了该方法的有效性和正确性。     

基于V-F变换的硅压阻压力传感器的处理电路

针对硅压阻压力传感器提出了一种基于电桥本身参数的温度自补偿方法,并设计了一种差分输入、双参数输出的高精度处理电路用以获得电桥参数。该电路用简单元件搭建差分输入的电荷平衡式V/F转换器,根据不同组态的频率输出解算电桥参数。该电路巧妙地利用差分输入方式消除了共模电压引起的误差,巧妙借用参考电阻消除了基准频率的影响,最终的输出频率只与被测量和参考电阻有关。经实验验证,电桥电阻的测量精度能达到0.0068%,经补偿后的压力传感器精度可达0.039%,相比补偿之前提高了一个数量级。     

具有自动标定功能的发酵罐多点温度采集系统

为系统地研究发酵罐内的温度分布,开发啤酒、制药等行业所需的端面测温传感器,本文利用自制的测量多点温度的传感器,采用热电阻自动标定、曲线分段拟合非线性校正和热电阻矩阵网络等多种处理方法及微功耗的单片机技术,设计了一种新型的计算机多点温度采集系统。温度测量精度达0.1℃,完全满足系统精度要求。     

一种新型热电阻温度传感器测量电路

一、引言 目前,热电阻和热电偶是工业生产过程自动化最常用的两种温度传感器。热电阻由于在测量灵敏度、线性度等诸多方面均优于热电偶,因此,在600℃以下的低温区得到了更广泛的应用。鉴此,进一步探讨与这种传感器配用的测量电路具有重要意义。 二、测量电路必须考虑的基本问题 热电阻传感器的工作原理是将被测温度的变化转换成电阻的变化,要想获取被测温度信号,必须通过测量电路才能实现。因此,测量电路性能的好坏直接关系到测量结果的精确程度。根据测量电路本身的作用,不论采用何种方式,都要考虑以下一些基本问题。     

三线制铂电阻高精度测温方法

基于可补偿引线电阻影响的三线制铂电阻测量电路提出了一种高精度测温方法.该方法利用双积分ADC,采用比例法测量铂电阻的阻值,并可补偿测量电路的误差.误差分析表明,在环境温度变化±10℃的条件下,对0～500℃测温范围其测温误差不大于10-3.     

基于铂热电阻的高温检测系统设计与优化

为了实现基于金属铂材料制作的热电阻温度传感器在高温测量环境下实现对温度数据的高精度测量,提出一种基于优化电路参数及阻温方程参数的温度检测系统设计方案。设计利用恒压源电路,获得稳定的理想电压,通过不平衡电桥差分放大电路和二阶有源滤波电路得到理想采集信号;设计优化了电路参数,校正了铂热电阻因高温产生的非线性。通过熔融沉积成型(FDM) 3D打印喷头实验平台,验证了设计方案的有效性,实现了在高温测量环境下对温度数据高精度测量的目的。     

工业热电阻测温输入电路

一、热电阻测温输入电路对于一个测温精度较高的温控系统,信号提取部分的设计是关键.热电阻测温输入电路,总的来讲是R/V转换电路,就是如何把温度t下的电阻相对0℃时电阻的变化值△R_t转换成对应的电压V,即V=f(△R_t).电阻/电压转换电路有两种基本的转换形式,即不平衡电桥电阻/电压转换电路和恒流源电阻/电压转换电路.本节主要讨论恒流源电阻/电压转换电路.     

基于STM32的建筑物接地电阻检测仪的研制

针对目前建筑物接地电阻检测装置存在的缺陷,提出一种基于STM32的建筑物接地电阻检测的系统方案。该方案根据三极补偿原理,采用嵌入式系统控制的主从机软硬件实现接地电阻的精确测量。检测系统包括交流合成、信号采集和数据处理三部分。检测系统由STM32控制产生频率精度高、波形稳定的交流电流注入接地网,对地网中的电压电流信号经带通滤波、差分放大、同步AD转换、FFT处理得到精确地接地电阻值。本检测系统能够提高检测精度以及检测效率,实现检测工作的智能化。     

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     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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。