高精度井下存储式电子压力计的设计

为了更准确地测取地层压力数据,研制了高精度井下存储式电子压力计.该压力计由井下仪器和地面处理2个部分组成:井下仪器以ADuC834单片机为核心,完成井内压力和温度的采集和存储;地面处理实现井下数据回放和处理.详述了该仪器结构和指标、系统硬件设计以及软件设计方案,并对压力计的性能进行测试.测试及现场工作表明,该仪表能够实现-40℃～150℃范围内的压力测量,测压精度达到0.05%,满足井下测试要求.     

油井温度,压力测量

介绍了油井井下温度，压力，深度测量仪表的工作原理及基本结构，阐述了检测与传输方式的特点，提高测量精度和传输的可靠性。测量精度与测量时间成正比，远距离传输电缆的分布参数影响等问题。     

煤矿井下温湿度监测和光纤通信系统的研究

针对煤矿井下采用热电偶测量环境温度的缺点,文章提出了一种基于单片机MSP430控制数字温度传感器DS18B20实现矿井下温湿度监测和光纤通信系统的设计方案。该系统通过单片机MSP430控制温度传感器DS18B20实现对煤矿井下的温湿度数据的采集;采用光纤传输实现温湿度信号的无失真传输;采用温湿度监控软件,通过串口通信,在PC机上实时监控系统的温湿度。实际测试表明,该系统工作稳定,温度测量精度达0.1℃,湿度测量精度达1%RH,可实现可靠的数据传输。     

基于MATLab的传感器精度校准方法

传感器为高精度仪器,由于设计原因或外界因素的干扰,会对传感器测量精度产生影响,介绍一种基于MATLab精度校准算法,以对温度敏感且本身设计存在缺陷的压力传感器为例,通过对该传感器温度t与压力p的电压数据进行实验标定、回归校准、融合计算,实现在温度因素影响下压力数据的精度校准.实验表明,该方法可明显提高测量精度.     

基于嵌入式分布多点的温度监测系统的设计

论文提出了一种基于实时操作系统,采用高速的ARM9嵌入式处理器和数字温度传感器LTM8877组成的温度采集监控系统.温度传感器可组网,实现了分布式多点的温度监测.完成对温度的采集、运算、传输和显示.温度数据具有直观性、准确性.用最小二乘法对数据进行补偿.并根据实际测量,给出了提高传输距离与测量精度的关键技术.     

基于岭回归的压力传感器高精度测量模型研究

硅压阻式压力传感器测量精度易受环境温度影响,为提高压力传感器测量精度,提出基于岭回归方法的高精度压力测量回归模型,采用新的测量方式从压力元件桥路提取压力传感器温度、压力变化的信息,建立了压力传感器桥路输出、桥路电阻与被测压力三者之间的回归模型,并利用Bootstrap方法对模型参数进行显著性检验,提高模型的稳定性.实验结果显示该方法可大幅度消除温度对压力测量精度的影响,使压力测量精度从±0.6% FS提高到±0.03% FS.     

基于CAN总线的智能型井下压力传感器监测系统设计

套管阀是实施主过程欠平衡钻井的关键工具。结合胜利油田井下压力监测系统进行研究,设计并实现了一种基于CAN总线技术以超低功耗单片机MSP430为核心的具有温度补偿的智能型压力传感器监测系统,对井下的实时压力及温度信号进行实时采集,为井下套管阀开启提供保证。采用硬件补偿以及曲线拟合和牛顿插值法进行软件温度补偿,有效解决了由于温度变化对压力测量带来的影响;采用CAN总线及光电隔离等技术,抗干扰能力比较强,传输距离长,可达10km。通过实验证明,本系统实时性好,精度误差达0.75%,足以满足套管阀阀底压力监测系统研制要求。     

基于铂电阻的温度测量仪的设计与实现

针对大亚湾中微子实验中,需要精确测量掺钆液闪温度的问题,设计并实现了一种基于铂电阻的分布式温度测量仪;该测量仪可以同时测量多点的温度,并将测量结果通过网络传输到数据服务器中,从而实现远程在线监测;为解决器件温漂带来的误差问题,该文采用了3电阻测量法的自校正技术,通过比较3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;通过计量炉的实测的数据比较,测量误差小于0.059℃,满足测量精度需求。     

一种超宽温度补偿高精度压力传感器设计

设计了一种用于井下测量的具有超宽温度补偿的压力传感器,该传感器使用基于CPLD实现的多周期同步测频法的双通道频率计完成高精度的压力及温度测量.该仪器包含石英晶体压力传感器、带数字温度补偿晶体振荡器(TCXO)的双通道频率计、含非易失性存储器和用于外部总线通讯的RS485收发器的数据接口,分度拟合系数及数字时钟温度补偿的修正系数保存在微控制器内部的模拟EEPROM中.该压力传感器比国外产品成本低,精度为0.02%F.S..     

基于模拟油井的井下测试仪温度修正校准方法

针对石油井下射孔压力测试中,在射孔完井过程中会释放大量的热量,压阻式压力传感器的温度效应成为影响测试精度的主要因素。为准确测取井下压力,用现有模拟油井试验装置模拟井内高温高压环境建立了校准系统。在多个温度环境下进行校准试验,通过与溯源性校准的标准测试系统的对比计算,利用最小二乘法得出压阻传感器在不同温度条件下的灵敏度,根据测试仪采集的实时温度数据值修正了压力数据,计算表明压力曲线峰值比修正前小1.4 MPa,为压力峰值的2.08%,表明该压阻传感器温度效应产生的影响不可忽略,基于模拟油井的温度修正校准方法能有效减小温度效应的影响,提高了测试精度。     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。