海流干扰下海洋观测平台动力定位

针对小型海洋观测平台,考虑其特殊的回转体形状,建立海流干扰下的运动学模型,针对螺旋桨的环形布置形式制订相应的推力分配方案．通过搭建半物理仿真平台,模拟平台在海流大小不同且方向相同、以及海流大小相同且方向不同时的动力定位过程,结果表明：平台可在海流干扰下完成动力定位且启动快速、定位准确、控制稳定性好．最后通过设计水池试验验证海洋观测平台在静水和海流干扰下的位置控制和艏向控制性能,结果显示海洋观测平台能在期望精度内完成动力定位．发现平台对转艏力矩较为敏感,因平台为回转体形状,在单独控制艏向时,只需较小的推力即可完成定位并且不会对位置控制产生明显的影响;而在进行位置控制时,因为海流和形状的影响,平台需要输出较大的推力．后者情况下,推进器一旦出现推力输出不协调,产生的附加转艏力矩将会对艏向控制产生不可忽视的影响．     

远心镜头在回转体测量系统中的应用

介绍了一种接触测量和非接触测量相结合的回转体测量系统,分析了远心镜头在非接触测量部分的应用。阐述了回转体测量系统的结构和测量方案;讨论了待测回转体的特性参数,指出为了提高测量速度需尽可能采用非接触测量方法;使用远心镜头和平行光源进行了相关实验。结果表明:远心镜头的平行投影能有效地解决回转体工件平面特征成像轮廓线的干扰问题。     

基于直流载波通信的LAMOST控制系统设计

在郭守敬望远镜(LAMOST)的光纤定位单元控制系统中,为了尽量减少线缆对控制系统的影响,现有控制系统采用的是ZigBee无线控制方式.下一代在建新望远镜将提高单元密度,然而ZigBee无线通信在更高单元密度和部分特定场合受到限制,而LAMOST安装要求又导致有线通信方式无法安装,因此,发展基于电力线载波通信的控制方式将增加其适用性.针对现有线路,设计了一套基于直流载波通信的光纤定位单元控制系统,包含主节点和从节点电路,采用专用的主从载波通信芯片PB620+PB331,通过现有电源线,实现双向传输数据,并控制步进电机运动,实现光纤单元定位.目前通过实验验证,实现了设计要求和目标,与原系统相比,未增加布线,且将无线通信方式改为了有线通信方式,提升了系统的稳定性和适用性.     

基于单片机控制的智能多相位交通控制信号机

为了提高道路交叉口的通行能力,提出了一种融入计算机技术、网络通讯技术和电子、自动化技术而设计的基于单片机控制的智能多相位交通控制信号机。文中首先介绍了智能多相位交通控制信号机的控制原理和控制方式,然后详细介绍了其功能、硬件组成及软件设计。     

空中回转体目标识别算法的研究

为加强空中回转体目标识别的智能化程度,提高目标识别率,对目标图像的不变矩特征与BP神经网络相结合的空中回转体日标识别方法进行了研究.以给出权值的方式引入Relief算法对目标图像的7个Hu氏不变矩、3个仿射不变矩的识别性能进行科学的评估.选出权值较大的特征量作为BP神经网络的输入特征来训练网络,识别样本.模拟实验表明:引入Relief算法对空中回转体目标不变矩选择的目标识别方案是有效的,应用Relief算法选择出的特征项作为神经网络的输入特征不但减少了特征量提取的采集次数,降低了算法的计算量,而且,可使网络更易于收敛.且提高了目标物的识别率.     

斗轮堆取料机取料流量控制方式的比较研究

针对悬臂式斗轮机恒速回转取料时存在取料不均、取料效率低和自动化程度不高等缺点,以及角度余弦开环控制方式不能处理料堆塌方等突发情况,提出了视频流量闭环控制方式.该控制方式通过实时检测取料瞬时流量,自动控制斗轮机悬臂的回转速度进行取料.对比研究及运行结果表明,该方式提高了取料效率,达到了节能增效的日的.     

异形支座类零件特征拼装中CAD/CAPP的集成

目前,国内外对回转体零件CAD/CAPP集成系统的研究比较成熟,而对非回转体零件CAD/CAPP集成系统的研究还处于研制阶段。现有的系统只依靠包含几何信息的IGES中性标准传递信息实现集成,仍没有较好的考虑到CAD/CAPP集成。本文采用特征拼装及特征单元的参数化设计方法,对基于特征拼装的异形支座类零件CAD/CAPP集成的几个关键技术和过程进行研究,并通过研制结果来证实其设计合理性和可行性。其设计思路对其它非回转体零件CAD/CAPP集成的研究同样有参考价值。     

回转体内腔测量的虚拟防碰撞算法

由于工件的遮挡,无法直接观察回转体测量机内表面测量系统的运行情况。为防止非接触测头与工件在测量过程中发生碰撞,利用OpenGL建立了回转体测量机的虚拟三维运动仿真模型进行实时监测。同时,提出了虚拟环境下一种基于点面最短有效距离的防碰撞算法,通过软件监控关键点与待测物体表面的距离作为真实系统的防碰撞检测依据,并且将其应用于虚拟回转体测量系统中,作为防止测头与回转体工件碰撞的重要手段。实验证明测试点与工件内表面最小距离控制在误差允许的范围内,而且系统运行时能够在测头与工件碰撞产生前及时发出警报,停止当前的测量机运行,可以有效避免测头与工件之间的碰撞。该算法具有判断简单、响应快速的特点,对于非接触测量中测头的安全防护具有实际的工作意义。     

基于尺度的回转体流噪声特性探究

以SUBOFF潜艇回转体纵缝开孔模型为基础,进行2、3、4、5、6、7、8等比例放大,基于LES大涡湍流模型对流水孔三维流场进行数值模拟;通过设置不同的流噪声监测点,将八组尺度计算结果进行对比,研究了回转体多尺度流噪声对比、等距离和等位置的衰减特性;结果表明:8组模型尺度的变化与总声级的关系并不是单调的,总声级随着尺度的变大有变小的趋势;充分考虑湍流附面层的影响,回转体尺度越大,其等距离衰减量越小;在流场相同位置处,随着回转体尺度的增大,流噪声呈现先增大后减小而后再增大的规律;以上结论可为回转体模型流水孔的设计提供参考。     

基于ObjectARX的回转体图形自动生成算法

利用ObjectARX工具包实现回转体图形生成算法。目的是对输入的回转体关键数据进行组织后自动绘出回转体图形,省却了原绘制此类零件繁琐、耗时的方法。以此算法编制的程序,也可为AutoCAD上的一外挂模块,具有良好的应用前景,并对工程设计出图过程有较好的增效作用。     

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。