基于量子进化的给定围长图构造算法

构造给定围长的极图是图论难题之一,特别是在顶点数规模不断增大的情况下会出现组合爆炸的现象。针对该问题,提出一种构造给定围长图的算法,通过在生成个体、调整个体中充分利用极图的特性,使算法达到较高的收敛速度与收敛精度。实验结果表明,通过构造围长为10的图,与粒子群优化算法、遗传算法相比,该算法达到次优解和最优解的准确率最高,构造围长为11的图,可得到相应的极图边数的下界。     

四正则图的交叉数

利用计算机对图的交叉数进行研究,给出了利用分支界限法计算图的交叉数的算法CCN(calculatecrossing number),并利用该算法计算出n≤12的所有四正则图的交叉数以及n≤16的随机四正则图的交叉数.同时计算出n≤12的所有四正则图的平均交叉数Aac(n)和n≤16的随机四正则图的平均交叉数Aac(n),根据计算结果提出四正则图的平均交叉数为O(n相似文献   

参数为k的几乎树中的染色多路割

染色多路割问题源于对等网络中的数据分片,是传统多路割问题的推广。给定颜色相关边赋权图G和G上若干特异顶点的局部染色,将该局部染色扩展到所有顶点上,使得两端点染不同颜色的边的权和最小。对于参数为k的几乎树,给出了多项式时间精确算法。也就是说,染色多路割问题是固定参数可解的,其中的参数k是使得G中任意双连通分支C成为树所要拿掉的最大边数。     

多边形外部Voronoi 图顶点和边数的上界

在对多边形P的外部Voronoi图的性质进行研究的基础上,将其表示成树结构并利用树结构的性质给出了其所含Voronoi顶点和边数的上界n+s+2×h-r-t-2和2×n+2×s+3×h-r-t-3,其中,h,n和s分别是P的边界、边和凸顶点的数目;t和r分别是位于P的凸包上的顶点和边数.同时,给出了每一个Voronoi区域所包含顶点和边数的平均值估计.文中工作在基于多边形外部Voronoi图的碰撞检测算法的复杂度分析方面有着重要作用.     

给定匹配数的单圈图的最小值

图[G]的广义Randic指标定义为[Rα（G）=uv∈E（G）（dudv）α],其中[α]为任意实数,[du]为顶点[u]的度。顶点数等于边数的简单图称为单圈图。在匹配数等于边数的情况下,通过分类讨论,给出当[-1.39≤a≤-1]时,相应单圈图的广义Randic指标的最小值,并给出相应的结构图。     

低度图的最大团求解算法

在图的最大团问题中,当图的顶点数不大于阈值m时,很容易求解其最大团问题,求解算法的时间复杂度为O(d)。给出一种求解低度图的最大团的确定性算法。该算法通过对图按顶点逐步分解实现分别计算,较好地解决低度图的最大团问题。算法时间复杂度为O(d•n3)。其中,n表示图的顶点数,图中顶点的最大度小于m或者图可以通过逐个删除度小于m的顶点而使所有顶点的度都小于m。     

广义Kautz有向图GK(3,n)的反馈数的界

对于给定的图G的顶点集的子集F,如果删除F使得剩余子图是无圈子图,则称子集F为图G的反馈点集。研究了广义Kautz有向图GK(d,n)的反馈点集。令f(d,n)表示广义Kautz有向图GK(d,n)的所有反馈集合中顶点个数最少的集合的个数(即广义Kautz有向图GK(d,n)的反馈数),给出了GK(3,n)的反馈数的上界,即 f(3,n)≤n+5n8 － 3n4－ 4n7+3。     

大图结构特征对划分效果的影响

针对大图结构特征如何影响划分效果这一问题,提出一种通过顶点度分布特征来描述大图结构特征的方法。首先,基于真实的图数据产生若干顶点数和边数相同、但结构特征不同的仿真数据集,通过实验计算真实图与仿真图之间的相似度,证明该方法对描述真实大图结构特征的有效性。然后,通过Hash和点对交换划分算法,验证图结构特征与划分效果之间的关系。当点对交换划分算法执行到5万次时,划分一个有6301个顶点和20777条边的真实图其交叉边数比Hash划分算法降低了54.32%,划分仿真图数据集中结构特征差异明显的两个图时,交叉边数分别为6233和316。实验结果表明,点对交换划分算法能够减少交叉边数,图的顶点度分布差异越大,划分后交叉边数越少,划分效果越好,因此大图结构特征影响其划分效果,这为建立图的结构特征与划分效果之间的关系模型研究奠定了基础。     

分子图拓扑指标逆问题的研究

当今组合化学的一个中心问题就是寻找具有某种化学或物理性质的分子，因此分子图拓扑指标及其逆问题的研究在组合化学中占有非常重要的地位。文章首先研究了化学分子图的一类Zagreb指标的逆问题，解决了其存在性问题和极值问题。从而为利用计算机搜索具有给定Zagreb指标值的所有分子图界定了顶点数和边数的范围，提高了计算机搜索的效率，这在组合化学中具有重要的意义。同时文章给出了计算树的Hosoya指标值的一个线性时间算法，并证明了其逆问题——SUBTREEVALuE问题是NP-完备的。     

有向无环图最小度生成树问题的一种近似算法

计算具有较小度的生成树是算法与复杂性研究的一个基本问题,同时在网络设计等领域具有重要应用.给定具有n个顶点的有向无环图G=(V,E)和根顶点r∈ V,最小度生成树问题欲求一棵以r为根的生成树T,使得在G的所有以r为根的生成树中T的最大度最小.给出该问题的一种迭代的多项式时间近似算法.该算法所求树的度不超过△*+1,其中△*为某一最优树的度.算法的时间复杂度为O(n2logn),其中n为顶点数目.算法没有运用过多的枚举,其实际运行时间要快得多.     

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.