基于ACIS平台的大型三维CAD系统的设计与开发

该文介绍了一个基于ACIS平台的大型三维CAD系统的设计、开发与应用。分别介绍了该系统的交互系统、造型系统和渲染系统的设计与实现。设计了一个栈式命令处理系统，便于实现异常复杂的用户交互命令。简要介绍了特征造型功能在ACIS平台上的实现。在ACIS框架上自选算法，重新设计了渲染引擎，扩展了渲染数据结构和功能，克服了ACIS提供的渲染引擎的局限性，得到了独特的渲染效果。最后介绍了本系统的应用情况。     

基于ACIS/HOOPS的特征造型系统设计与实现

为了探索CAD/CAM领域中的特征造型关键技术,研发一个特征造型系统。该系统分别以ACIS和HOOPS为几何造型引擎和渲染引擎,能够实现常用特征的创建、特征历史的管理、基本约束的管理和特征模型与几何模型的存取等功能,并且支持一些自由曲面特征造型以及参数化设计。为了维护用户的隐含设计意图,系统采用了一种新的拓扑元素命名与辨识机制。最后,给出了使用该系统进行特征建模、自由曲面特征参数化设计以及设计意图有效维护等实例,验证了本系统的可行性和有效性。     

基于HOOPS接口技术的3D造型的研究*

ACIS是全球著名的3D造型软件开发平台,介绍了ACIS的新接口技术——HOOPS以及它的组件、功能、特色和应用,展示了一个应用开发实例。     

三维可视化桥梁健康监测系统的架构设计

本文就大型桥梁的三维可视化远程健康监测系统的软件显示端整体架构的设计与实现展开了讨论,本系统主要监测桥梁的应变、位移、振动、索力、温度等参数。软件开发中主要涉及到了ACIS三维建模引擎,HOOPS三维渲染引擎,GDI＋图形绘制接口,ODBC数据库操作接口,BCGControlBar界面设计类库等技术,按照现代软件工程的思想,设计出一个完整的系统架构,使以上模块以高内聚,低耦合的方式相互协调的工作。     

基于MNF文件的柔性体云图动画的实现

针对国内拥有自主知识产权的多领域仿真系统中柔性体仿真功能较弱的问题,基于浮动坐标法,采用MNF文件,在多领域系统建模与仿真平台MWorks上,借助ACIS和HOOPS图形引擎,实现柔性体三维云图动画显示的功能.介绍柔性体仿真系统的组成以及MNF文件的内容与作用,阐述柔性体云图动画实现的几项关键技术,包括几何模型的创建、...     

ACIS/HOOPS几何建模与可视化技术研究与应用

几何建模与可视化是数值模拟前处理中重要的组成部分.重点介绍了ACIS建模技术及HOOPS可视化技术,并基于ACIS/HOOPS及格式转换组件(InterOp)、模型简化组件(Defeaturing)、网格划分组件(VisTools)等3D组件开发了数值建模与可视化软件,在系统中实现几何建模、模型导人、模型简化、网格划分及可视化功能,为后续的数值模拟奠定了良好的基础.应用表明:使用ACIS/HOOPS及相关3D组件开发数值模拟前处理系统具有效率高、效果好的特点.     

基于ACIS平台的三维参数化实体造型设计

介绍了ACIS开发平台和参数化造型技术,并对基于ACIS平台的三维参数化实体造型系统的实现方法进行了深入研究,运用面向对象思想,给出了实现系统的框架结构.     

支持进化的协同设计系统研究及实现

提出了一个支持进化的协同设计框架系统clientAgentDcsign1.0,将进化技术和协同技术结合到一起用于新产品的开发。系统利用改进后的遗传算法实现进化设计,多Agcnt则为协同环境提供框架支持。以此系统为基础,以Vc 6．0及实体造型引擎ACIS为工具开发了一个用于建筑设计的协同创新平台HouseDev。     

基于HOOPS\ACIS的CAD文件模型处理系统

具有CAD功能的软件系统都会面临模型文件的处理问题,探讨了在HOOPS\ACIS平台下搭建具有CAD功能的软件系统以及如何实现CAD文件模型处理的问题,阐述了CAD文件模型处理系统的模块划分,简述了主要模块的实现功能和采用的技术实现方式。     

一种基于ACIS平台的创新进化设计方法

随着智能计算机辅助设计技术的发展,进化设计方法已经成为最重要的创新设计技术之一.众多的造型平台又为CAD系统的开发提供强大的支持.将遗传算法应用于创新设计时,容易受到造型工具和设计者自身创新能力的限制.文中提出一种将遗传算法和特定的造型技术相结合的创新设计方法.该方法充分利用遗传算法的进化功能和ACIS平台强大的造型优势,通过进化产生更具创意的产品造型,为设计者的创新设计提供更强大的支持.实验表明,该方法在创新进化系统中有很好的应用前景.     

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.