体绘制方法研究与实现

体绘制方法是当前研究的一个热点问题,它的应用遍及医学、地质学、物理学、和科学计算等诸多领域。但目前它仍处于发展阶段,有许多问题都有待于进一步的研究。该文对体绘制方法中的若干算法进行了研究与比较,实现的算法是基于开发平台windows SDK,用C语言和原始的API编写Windows程序,以提供最佳的性能、最强大的功能和最大的灵活性。     

几种变换域体绘制算法的比较研究

医学图像三维重建技术具有重要的学术意义和应用价值。变换域体绘制是该重建技术的一个新兴的重要分类,目前它已成为一个热点研究方向。综述了变换域体绘制下的傅里叶体绘制、哈特里体绘制、小波域射线投射法、小波足迹法典型算法的算法思想和优缺点,而且通过列表与其它三维医学图像可视化算法的特点及性能进行了分析比较,从而得出变换域体绘制具有绘制速度快、图像品质高等其它绘制算法不可比拟的优点及其相应的改进之处。     

几种变换域体绘制算法的比较研究

医学图像三维重建技术具有重要的学术意义和应用价值.变换域体绘制是该重建技术的一个新兴的重要分类,目前它已成为一个热点研究方向.综述了变换域体绘制下的傅里叶体绘制、哈特里体绘制、小波域射线投射法、小波足迹法典型算法的算法思想和优缺点,而且通过列表与其它三维医学图像可视化算法的特点及性能进行了分析比较,从而得出变换域体绘制具有绘制速度快、图像品质高等其它绘制算法不可比拟的优点及其相应的改进之处.     

基于硬件加速的纹理映射体绘制

介绍了体绘制的概念及其在计算机绘图中的重要性。提出了利用图形显示卡的相关性纹理和多重纹理映射功能对三维纹理进行有效改进的新算法,研究了该算法在体绘制中的应用,结果表明,它在快速、准确重建和交互性方面具有优势,对于提高体绘制的效率具有重要的意义。     

医学体数据三维可视化方法的分类与评价

医学图象三维可视化具有极大的医学研究和临床诊疗应用前景,是现代医学影象研究的重要领域。医学图象三维可视化方法通常分为表面绘制和体绘制,已有许多具体的算法提出,一些算法兼具表面绘制和体绘制的特点,归为混合绘制方法,该文概述了一些典型算法,并讨论了其特点及相互联系,同时对各类方法的应用场合及前景了分析和评价。     

基于空间数据插值算法的空间散乱数据体绘制实现

体绘制技术是一种能够真实地反映空间数据场内部信息的可视化技术。在体绘制研究领域中,非规则的空间散乱数据体绘制目前仍然是一个研究热点。文中采用空间数据插值算法对散乱的原始数据进行网格化插值,然后使用光投影体绘制算法对规则网格数据进行体绘制。最后,通过新方法实现了某油藏区地下流体压力和孔隙度分布结构的体绘制。     

光线跟踪方法在体绘制中的应用与发展

针对光线跟踪方法存在求交计算量大、实时交互性差等缺点.从体光线跟踪算法、基于图形硬件加速的光线跟踪体绘制方法,并行光线跟踪体绘制技术这3个方面,对国内外光线跟踪方法在体绘制中的应用技术进行了分类描述与综述,重点介绍了体光照模型、光线跟踪混合绘制、基于可编程硬件加速、并行绘制算法及体系结构,并结合应用阐述了各自特点及其相互联系,最后对光线跟踪方法在体绘制的应用提出了研究建议.     

一种改进求交的自适应光线投射体绘制算法

光线投射算法是体绘制技术中的一种重要算法,但其自身存在采样效率低和绘制速度慢等问题。为了提高光线投射算法的绘制速度,本文提出了一种改进求交的自适应光线投射体绘制算法,算法采用一种快速求交方法和自适应采样来提高体绘制速度,试验结果表明该算法能在基本不影响图像质量的同时提高算法的速度。     

体绘制技术在医学可视化中的新发展

科学计算可视化体绘制算法能反映出体数据的内部信息，在医学，它已经从辅诊断发展成为辅助治疗的重要手段，体可视化技术是医学可视化的重要研究内容，其处理过程包括体数据的获取，模型的建立，数据的映射，绘制等操作，该文介绍了医学可视化中常使用的几种光照模型，针对基于图象空间和对象空间两种体绘制算法，介绍了它们的基本思想方法，并详细阐述了在近期的主要加速技术和提高图象质量方法的新进展，最后给出了实验数据和结论。     

四种体绘制算法的分析与评价

体绘制技术是科学计算可视化的重要组成部分,具有较大的研究价值和广阔的应用前景。体绘制有两种方法即间接体绘制和直接体绘制,直接体绘制(简称体绘制)以其在体数据处理及特征信息表现方面的优势,已经得到了研究者越来越多的重视。文章对四种典型的体绘制算法进行了描述,并概述了它们的改进之处,同时对它们各自的性能进行了分析和评价。     

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。