超声速弹丸着靶时刻声学测试方法

针对超声速弹丸终点弹道着靶时刻测试问题,研究了声学传感器测试机理,建立了声波延迟触发模型,开发了一套着靶时刻测试系统。采用传感器阵列采集超声速弹丸激波到达不同传感器的时间差,建立了测量超声速弹丸着靶时刻的数学模型,该模型包含了传感器坐标、时间差和弹丸着靶时刻。针对直线形传声器布阵,基于高斯-牛顿法对定位模型进行解算,分析了高斯-牛顿法的迭代公式、收敛性和适定性等。通过计算机仿真分析了误差大小和传感器数目对误差的影响。通过模拟试验数据计算表明,声学测试结果与实际结果一致。该方法应用在某型高炮试验任务中,成功测试了弹丸着靶时刻。     

多线阵光电立靶弹丸攻角测量

基于立靶坐标交汇测量原理,介绍了传统单线阵CCD立靶系统,并对单线阵CCD立靶系统中弹丸攻角测量方法进行了分析,指出了其中存在的扫描帧频不足和弹头、弹尾着靶点距离误差的问题.在此基础上,提出了一种新的多阵列光电立靶测量系统的布设方法,利用6个交汇列图像在空间交汇组成光幕阵列,根据飞行弹丸穿越不同光幕阵列的时刻和多光幕立靶系统结构参数,提出了一种新的计算弹丸攻角的方法.利用多线阵光电立靶测量系统巧妙地避免了弹头、弹尾着靶点距离误差对测量结果的影响,保证了测量精度,降低了系统成本.     

微型计算机在声学靶中的应用

本文主要介绍TRS-80微型计算机在利用声学定位方法测定超声速弹丸的弹着点(简称声学靶)中的应用,简单介绍了整个声学靶系统,给出了各有关的计算方法,以及应用TRS-80微型机测定弹着点的程序流程和清单。对于声学定位仪与TRS-80之间的I/O接口,和教据采集程序也作了详细叙述。     

一种基于光纤光栅压力传感阵列的飞机燃油液位测量方法研究

本文提出了一种基于光纤光栅压力传感器阵列的飞机燃油液位传感系统,研究了基于聚氨酯材料的压力敏感薄膜和光纤光栅压力传感器的制造工艺,通过光纤光栅(FBG)压力传感器阵列搭建了燃油液位传感系统,开展了液位传感实验。实验结果表明,该系统在75cm液位量程范围内可实现16.09pm/cm的测量灵敏度,最大相对误差<４％。论文提出的基于线性拟合曲线截距测量的液位高度计算方法,可以克服实际应用中测量液体密度和重力加速度变化对液位测量精度的影响,保证了系统的检测精度。该光纤光栅液位传感器为飞机燃油液位检测提供了一种新的技术思路。     

适用于动态对焦的高精度灵活标定方法*

处于动态对焦过程及不同对焦状态下的相机内参会不断变化.文中通过在镜头对焦环上加装角度传感器的方式,提出基于动态对焦过程以主距增量为参数的相机模型,实现任意对焦状态和距离下相机内参数的求解.利用定制的三平面立体标定靶,设计一种高鲁棒性的标定方法.与传统模型相比,该模型基本未增加额外约束条件,可操作性较强.实验表明,文中模型及相应标定方法具有更强的图像校正能力,从而提高摄影测量精度.     

三目视觉测量系统在风洞试验中的应用研究

针对立体视觉测量技术在风洞试验中的应用特征,设计基于线阵CCD的三目视觉立体测量系统。利用基于双高斯物镜的组合透镜,在降低光学畸变的前提下实现点光源到线光源的变换。组合镜头可对CCD进行三自由度微调,保证测量目标成像于焦平面附近。在系统标定过程中利用三坐标测量机构建虚拟阵列靶,以最大限度地提高标定靶精度。实例应用结果表明,该系统能够实现三自由度虚拟飞行系统模型运动轨迹的追踪及自由振动系统机械阻尼的测量。     

弹丸侵彻靶板动能测试方法研究

弹丸动能是评价枪械毁伤能力的重要参数,现有动能测试主要采用动能公式进行间接测量,方法单一。从声发射技术的角度进行弹丸动能测试的研究,开展典型7.62 mm弹丸侵彻铝合金靶板的数值模拟研究,并获取声发射信号幅度和均方根(RMS);分别构建RMS和幅度值与动能的数学模型,其中构建的方程决定系数分别达到0.9936和0.9803;组建弹丸动能测试系统并实施弹丸侵彻动能试验,与铝箔靶测速试验对比分析结果表明:构建的RMS、幅度特征值和弹丸动能的数学模型具有合理的拟合精度,并且幅度参数表征弹丸动能的精度更高,两次试验测量误差分别达到12.7%和3.1%。所提出的声发射弹丸动能测试方法为弹丸动能直接测量提供了一种新概念解决方案。     

基于声光阵列的炸高测量技术研究

针对炸高测量系统结构复杂、布阵繁琐、低信噪比下的炸高测量精度偏低的问题,提出一种立体六元声光阵列的炸高测量方法;详细介绍了该方法的炸高测试原理及结构组成,应用Matlab建立了声光阵列结构的数学模型,深入分析了该结构的测量原理和最佳测量高度;仿真验证结果表明:该方法适用于爆炸高度为20～60 m范围内的炸高测量,测试时应保证爆炸声信号到达传感器的时延估计误差小于20μs、声光信号到达基阵时延估计误差绝对值在4 ms范围内;最终靶场实验结果表明:在低信噪比的情况下,采用立体六元声光阵列结合改进的广义二次互相关算法在最佳测量高度范围内的炸高测量精度达到5％,可以应用于靶场炸高测量.     

基于力敏导电橡胶的新型三维力柔性触觉传感器仿真研究

针对目前触觉传感器研究中不能兼有柔韧性和多维力测量等难题,设计了一种基于力敏导电橡胶的具有整体两层非对称网状式结构的触觉传感器,通过检测导电橡胶的电阻值变化来分析三维力信息。本文介绍了该传感器的基本结构,并基于理想力敏导电橡胶的力学特性建立了三维力并行测量的数学模型,通过对该模型的求解解决了三维力及各受力点之间复杂的耦合问题。仿真实验结果表明该传感器能够实现对表面任意单点三维力、多点三维力以及三维面力信息的测量。     

立靶光幕探测性能分析与弹丸信息提取研究

交汇立靶测量系统可以实现飞行弹丸的速度、着靶坐标测量,是靶场测试中不可缺少的测龟装置,然而,由于交汇立靶中的倾斜光幕存在,致使飞行弹丸在穿越光幕过程中的输出信息不一致,影响了测量精度;基于立靶测最系统原理,分析了立靶光幕的光学探测性能;从光学探测方面,研究与分析光幕幕厚、作用距离与光电探测输出信息的关系,并根据交汇光幕布阵的几何特点,提出采用相关算法对飞行弹丸穿越光幕信号的时刻提取,减少光幕幕厚不一致产生的计时误差,提高系统测量精度.     

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。