基于LabVIEW水声宽带功放信号发生控制系统设计

针对水声宽带信号复杂和功率放大匹配困难的问题,提出基于虚拟仪器技术的水声宽带功率放大及匹配系统发生器设计方法,并以LabVIEW(Laboratory Virtual Instrument Engineering Workbench)为平台设计开发了用于水声发射换能器的选择、阻抗匹配网络选择以及发射机使能状态信息控制等多功能水声宽带功放信号发生控制系统。该系统可以根据需求自定义选择配置发射连续或脉冲信号,运行测试其可以实现对发射功率大小、信号形式、阻抗匹配网络等参数选择,且减少了硬件开销,操作简便,便于推广。     

基于PCAuto、Excel与Matlab的通信系统应用

提出了一种基于PCAuto、Excel和Matlab的过程控制仿真系统,利用Matlab simulink搭建系统控制模型,通过Excel link实现对PCAuto与Matlab的数据交换,实现了PCAuo对Matlab的完全控制,简化了PCAuto和Matlab通信软件的设计,增加了控制系统性能指标的组态分析.     

基于组态王、Excel和Matlab的PID自整定仿真软件

提出了基于组态王、Excel 和 Matlab 的PID自整定仿真软件。该仿真软件用Mat lab完成PID自整定算法，用组态王工控软件实现复杂、友好的图形界面，Excel作为Matlab 和组态王的数据库。三者之间通过DDE协议进行数据链接。     

拾取回波信号时脉冲声控制方案的设计

在空气声中采用脉冲声进行吸声与隔声测量时,由于声源与传声器是分置工作的,脉冲声生成过程中,传声器与声源是同步工作方式.但在水声管中测量时,换能器往往采用“收发合置”的工作方式,脉冲声生成的方式是不同的.因此,提出了在拾取回波信号时脉冲声的时序控制方案.以MSP430F149单片机为硬件核心,设计了满足其时序要求的控制电路,利用MSP430F149单片机串行口通信,开发了基于LabWindows/CVI虚拟仪器技术的上位机测试平台,辅以信号发生器、数字示波器、功率放大器、信号调理器等测试仪器,通过对响应及驱动信号进行截短处理,在消声室中成功产生了可控脉冲声信号,为“收发合置”方式在水下环境中产生可控脉冲声奠定了基础.     

水声探测器测试系统设计与实现

为了提升水声探测性能,其探测器不断改造升级,传统利用各类标准台式仪器对其测试,在成本、检测周期、操作复杂度等方面均有明显的增加,鉴于以上问题,设计了一套自动化测试系统。阐述了测试系统设计原理、硬件设计方法、水声探测器各组件的测试软件设计方法。在测试软件设计中,对于信号幅度和频率计算方面,引入了基于自功率谱函数的快捷计算方法;对于CAN通信软件模块开发方面,提出了一种Database Edior机制,简化了CAN会话句柄创建过程,并应用stream模式实现CAN通信,提升了CAN帧数据接收效率;对于短调制脉冲信号测试,利用多线程结合通道触发的方法,实现了准确测试。采用该测试系统对水声探测器进行测试,效果表明,操作方便快捷、检测周期显著缩短、可靠稳定、完全达到了预期的效果。     

瞬态脉冲信号测量与处理系统设计

针对高强度脉冲中子控制系统的测试,需要对通过LabVIEW控制的数字示波器所捕获到的大量相似瞬态脉冲信号进一步测量与处理,以便筛选出符合系统控制要求的瞬态脉冲信号。考虑到瞬态脉冲信号的控制与采集设计也是通过LabVIEW进行控制,然而单独采用Matlab对信号进行分析处理,难以同时满足对海量数据进行测量与处理的设计需求。由于LabVIEW具有自动多线程技术、图形化设计语言和丰富信号处理模块,并且Matlab软件在对信号进行小波降噪方面具有优势,利用LabVIEW软件与Matlab软件混合编程,实现集时域测量、频域测量和小波降噪处理于一体的海量信号分析处理系统。实测结果验证了该系统应用于处理海量脉冲数据并筛选出有用信号的正确性及可行性,同时也表明了该系统具有操作简单、响应速度快、测量精度高的优点,具有较高的实用价值。     

水声材料性能测量中的数据采集与反滤波应用

用宽带脉冲代替传统的正弦脉冲进行叠加法测量,可以在一定程序上降低大面积水声材料自由场测量中的低频限。然而,这个声脉冲的脉宽和频谱受到发射换能器和功效响应的严格制约。文中将数字信号处理中的反滤波技术应用于水声性能的测量中,改进了这一修正的测量方法。先对水声器接收到的声脉冲进行数据采集,计算出测量系统的频率响应,然后对该系统进行反滤波处理,结果,使原来的声脉冲得到了时域上的压缩,扩展了测量频段,特别是     

多通道可重构水声信号采集模块设计

针对水声信号探测系统的需求,设计一种多通道可重构且小体积高集成度的水声信号采集模块。根据性能指标要求和水声信号特点,提出采集模块总体设计方案,硬件方面加入可重构带通滤波器增强采集模块的通用性,采用基于IEEE 1588V2标准的精确时间同步协议方案,提高多模块分布式应用时的系统采集同步精度;开发基于QT的处理机显控软件,实现采集控制与数据实时回看。对采集模块性能进行测试,其结果表明,该水声数据采集模块能够满足设计需求,其已在某声纳工程项目中得到实际应用。     

基于虚拟仪器的脉冲/直流电源检测系统

提出了一种基于虚拟仪器的直流/脉冲检测方案。该方案满足了兰州重离子加速器冷却储存环(HIRFL-CSR)电源测量的高精度等方面特殊要求,与传统仪器如高精度数字示波器等测量手段相比具有强大的数据数据分析与处理能力,可通过更新软件以实现不同的功能满足现场测量的要求,具有很强的灵活性。该方案已应用于实际电源测试中,取得了满意的效果。     

宽带RCS自动测试系统设计

为满足目标宽带雷达散射截面积(WB—RCS)理论研究的实验验证需要，绕过脉冲体制，提出了一套宽带扫频自动测量系统。介绍了该系统硬件、软件设计，特别是给出了一整套硬件、软件对消方案，大大降低了系统测试对信噪比的要求。经实际测试，满足设计要求，为指导理论深入研究提供了有力的实验支持。     

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.