基于有序简单多边形的平面点集凸包快速求取算法

凸包问题是计算几何的基本问题之一，在许多领域均有应用。传统平面点集凸包算法和简单多边形凸包算法平行发展，互不相干。本文将改进的简单多边形凸包算法应用于平面点集凸包问题中，提出了新的点集凸包算法。该算法首先淘汰掉明显不位于凸包上的点，然后对剩余点集排序，再将点集按照一定顺序串联成有序简单多边形，最后利用前瞻回溯方法搜索多边形凸包，从而得到点集的凸包。本文算法不仅达到了Ｏ的理论时间复杂度下限，而且算法     

一种确定点集最远点对的最优算法

提出了一种确定点集最远点对的最优算法.对平面内n个点的点集,在求出其凸包后,利用求对跖点对的方法确定凸包的最远点对,从而得到点集的最远点对.整个算法的时间复杂性为O(nlogn).     

确定多边形凸凹顶点的快速算法及其应用

提出一种确定任意多边形凸凹顶点的快速算法，该算法的时间复杂性为Ｏ（ｎ）次乘法和Ｏ（ｎ）次比较。还介绍把该算法用于求平面点集的凸包以及对任意的平面多边形进行Ｄｅｌａｕｎａｙ三角剖分。     

求解简单多边形和平面点集凸包的新算法

沿一定方向遍历凸多边形的边,其内部在边的同一侧。本文依据凸多边形的这一特性,提出求解简单多边形凸包的新算法,进而扩展得到求解平面点集凸包的新算法。新点集凸包算法先找到点集的极值点,得到极值点间的候选点子集,再求得相邻极值点间的有序凸包点列,最后顺序连接极值点间的有序凸包点列,得到凸包。新算法达到目前平面点集凸包问题的渐进最好算法的时间复杂度O（n log h）,其中,n为平面点集的点数,h为平面点集凸包的顶点数。相比相同复杂度的凸包算法,新算法简单、易于实现。又由于是顺序求得凸包上的点,新算法还具有更易于实现基于其上的有效空间算法的优点。     

平面点集凸包的最优实时算法

在星形多边形性质的基础之上,根据凸多边形是特殊的星形多边形,以星点为中心,以分别平行于x轴和y轴的直线作为相对坐标系的坐标轴,将平面区域划分为四个区,依据新的点与有向线段之间关系的判别式,从而简便快速地分离内部点和外部点,对外部点快速找到支撑点,提出了平面点集的最优实时算法,其时间复杂度为O(n).它同样适用于多边形并具有相同的时间复杂度.它还便于控制结果凸包的方向,只需调整初始三角形的方向即可,算法其它部分无需修改.算法具有高效、稳定等特点,从而在结合崔国华等的理论基础之上为找到一种线性的排序算法提供了实际的可能性.在文中的结论部分提供了本文算法和经典的Graham算法及堆式排序算法的执行时间的比较.     

一种高效的平面点集凸包递归算法

凸包是计算几何的基本结构, 在许多图形图像相关领域得到了广泛应用. 本文提出了一种简单快速的平面点集凸包算法, 使用了主成分分析法(Principle component analysis, PCA)对点集进行预处理, 并研究了适用的排序规则和凸包边缘点判定原则. 该算法已成功应用于一光栅投影三维形貌快速测量系统,对相位干涉图中密集残留点所形成的最小凸包进行提取. 系统将提取的凸包区域进行掩码标记, 从而避免密集残留点造成相位展开错误, 保证了三维形貌重构的准确性. 实验结果表明, 该算法准确可靠, 并且运行效率较高.     

平面点集三角剖分的算法

提出平面点集三角剖分的一种新的算法，该算法首先逐层求凸包，然后分割环或成三角形，最后调整相邻环域的三角剖分便圾获得最小权三角剖分。     

基于二维凸包的TSP算法

二维凸包是指包含平面点集的最小简单多边形,广泛应用于GIS.将二维凸包与TSP相结合,提出了基于二维凸包的TSP算法,首先快速凸包算法构造城市点集的凸包,该凸包是经过部分城市点且其余点都在其内部的回路.其次将其余的城市点依次插入回路形成新回路,使新回路的长度增量最小,直至所有的城市点都在回路上.在TSPLIB中的典型实例上的实验结果表明,该算法比简单遗传算法更快得到问题的近似解.     

一种平面点集凸包与三角网格综合生成的算法

平面点集作为一种觉数学模型,其上常做的运算是求其凸包和三角网格,目前二者的研究是独立进行的,鉴于在很多情形下这两种处理结果均需要,提出了一种综合算法：在对离散点集进行ｄｅｌａｕｎａｙ剖分的过程中,增加对三角形边界的判别、管理功能,记录其中作为点集凸包边界的线段,使得在实现剖分的同时产生出点集的凸包,从而提高了算法效率,且当该算法实现单一的点集剖分或凸包功能或是用于简单多边形的凸包与剖分时效果也很好     

计算平面点集凸包的实时插入算法

讨论平面点集的凸包实时插入算法。算法基于Graham扫描算法,对3个点检测顺序的转向。本文证明,当S的N个点以流的形式进入系统,计算S的凸包所需的检测次数小于3N。     

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。