连续式射频导纳物位仪

电容式物位测量仪表在测量粘附性材料物位时经常会出现挂料现象,因此运用范围受到了极大的限制。设计研制一种连续式射频导纳物位仪,在电容式物位仪表的基础上,采用无线电频率信号,并在电路内部增加了屏蔽电路和消除挂料电路,使其能够消除挂料对感测元件的影响。该仪器可以对物位进行连续测量,实时显示当前的物位信息,为全自动化物位测量创造了条件。     

基于虚拟仪器的远程物位测量

射频导纳物位仪在物位测量领域广泛应用,但其自动化程度有限。本文提出一种无人职守的全自动化的远程物位测量系统,运用虚拟仪器软件强大的数据处理能力列物位信息进行处理,而且利用虚拟仪器自身带有的网络发布功能实现远程实时监控和操作。     

新型射频电容式物位测量仪

为了测量具有不同导电性物料的高度、提高物位测量仪的抗干扰能力和测量精度,设计了一种单电极、两线制射频电容式物位测量仪.该测量仪基于电容充放电原理,以射频信号为激励,通过电容式传感器测量物位高度;采用差分补偿电容技术,有效地消除了寄生电容的影响;采用光耦隔离测量回路和控制回路,提高了电路的抗干扰能力.实测数据表明,所设计的电容式物位测量仪具有抗干扰能力强、稳定性好的特点.应用前景广泛.     

垂索式射频智能物位检测仪的研制

本文介绍一种基于射频导纳技术并以垂索作为探极的物位测量仪表,并对仪表主要测量原理、工艺结构、软硬件设计进行分析.该仪表具有数字显示,限位报警,抗干扰能力强的特点,已通过实验室测试,并在现场得到应用,取得预期效果.     

射频导纳连续测量仪表的研制

本文介绍一种基于射频导纳技术研制的连续测量仪表,并对仪表主要测量原理,工艺结构、硬件设计、软件流程、抗干扰设计进行分析。该仪表具有数字显示、限位报警、模拟量输出,物位连续跟踪的特点,已通过实验室测试,取得预期效果。     

取样脉冲对平衡式取样积分微分电路性能影响

取样脉冲是影响超宽带无线电引信接收机性能的关键因素。在分析取样积分微分电路工作原理的基础上,建立了其频域和时域数学模型。结合无载波信号的时域多普勒效应,提出了基于Matlab的超宽带无线电引信接收机输出信号时域仿真方法。研究了取样脉冲宽度和幅度对电路输出波形的影响,结果表明:电路完全对称时,输出信号幅度只与取样脉冲宽度有关,但并非单调关系;非对称时,电路达到稳态前产生一个脉冲信号,脉冲幅度与取样脉冲的幅度成正比,宽度成反比。     

基于荷重传感器的料仓物位测量装置的研制与开发

介绍一种基于荷重传感器的物位检测装置的设计方法,该装置利用电子秤的原理,通过计算将物料的重量转化成高度,达到了测量物位的目的.硬件部分主要包括应变电阻片、信号检测电路、数据采集与处理系统等.该设计在数据处理中引入了非线性处理方法,文中详细讨论并解决了信号测量过程中非线性所带来的问题,并给出了非线性处理过程中所造成的误差分析,在实际应用中有较高的实用价值.     

提高超声波物位检测精度方法的研究

针对超声物位检测中声速随温度变化、回波信号弱和信噪比低的问题,对提高超声物位检测系统的测量精度进行了研究.提出加装温度传感器和自校准装置两套温度补偿方案.针对回波信号弱的问题提出一种利用间歇混沌进行微弱信号检测的技术.给出理论分析和仿真试验.实验证明该方法可准确实现对回波信号的特征提取,具有较高的信噪比.     

核电站泄漏监测系统湿度取样时间优化研究

对第三代原子能反应堆核电站泄漏监测系统取样过程进行研究.介绍了当前核电站泄漏监测的现状,对各类泄漏监测方法的原理进行了调查.研究过程采用数值模拟方法,对湿度测量过程中的湿蒸汽取样机理进行研究.湿度取样测量方法相比其他方法,动态特性较差,测量结果显示存在滞后性.研究表明:泄漏监测系统当前采用的湿空气取样时间还有一定的优化...     

仿生原理在物位检测技术中的应用

在环境恶劣的条件下确定大容量贮存罐中的物料高度具有一定的难度，文章叙述了利用仿生原理提取、分析物位信号的过程。对在不同位置提取的信号利用小波分析等方法对信号的频率及能量进行比较，提取出物位的特征信息。测试方法及所需设备比较简单，能够在环境恶劣、贮存罐密闭的条件下确定物位的高度。应用范围比较广泛，为现代物位测量领域提供了一个新的思路和方法。     

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.