关于单纯形方法的若干新算法

引言自从Dantzig［1］在1947年提出解线性规划的单纯形方法以来，单纯形法作为主要算法已经得到了广泛的应用，并积累了丰富的经验．随着科学和经济的发展，迫切要求解决大型线性规划问题，需要进一步研究算法的效率．1972年，Klee-Minty［3］举出了一个用通常的单纯形法求解需要指数时间的反例．1982年，Smale［6］证明了单纯形方法的平均收敛速度是多项式时间的．本文根据作者的思想［12-14］，在单纯形方法的基础上，提出了三种新的选取换基变量的方法，由此产生的三个算法，从数值例子来看是高效率的．1．算法1．1．考虑如下的线性规…     

并行归并排序算法

构造效率为Ｏ（１）的并行算法是一个引人注目的问题。［１］和［２］分别提出了并行度为Ｏ（ｌｏｇｎ）和Ｏ（ｎ＾１／２）的、效率为Ｏ（１）的并行排序算法。本文提出一种新的并行排序算法，其效率为Ｏ（１），而并行步数小于［１］和［２］的算法的并行步数。经过改进后，在保持效率为Ｏ（１）的情况下，可进一步将并行度扩大到Ｏ（ｎ＾１／２ｌｏｇ ｎ）。     

非线性等式与不等式问题的信赖域算法

５１．引言 本文讨论如下非线性等式与不等式问题的求解问题：其中,吐。）是＊”＋Ｂ的连续可微函数． 非线性问题（１．１）广泛出现于优化问题、互补问题及变分不等式等应用数学领域中,因而对其算法的研究也是计算数学的一个重要部分．许多作者考察了该问题的求解,如Ｄｅｎｎｉｓ和Ｓｃｈｎａｂｅ［６］, Ｐｓｈｅｎｉｃｈｌｌｙｉ［９］, Ｒｏｂｉｎｓｏｎ［１０１等人讨论了该问题的牛顿法求解,梯度法求解,Ｂｕｒｋｅ和 Ｈａｎ［‘］讨论了高斯一牛顿法求解． Ｄｅｎｎｉｓ在［５］中首次采用了信赖域算法的求解,［５］中通过引…     

基于Samelson逆的矩阵ε-算法和η-算法及对矩阵指数的应用

１．引言矩阵Ｐａｄｅ逼近在常微分方程和偏微分方程的数值解,在变分原理、原子及初等粒子物理、自动控制理论的模型简化等领域中己经有深入的实际应用背景［１,２,１０］．文［３］给出一种新的基于Ｓａｍｅｌｓｏｎ逆的矩阵Ｐａｄｅ逼近（ＳＭＰＡ）．它在不降低逼近阶的前提下与原有的矩阵Ｐａｄｅ逼近方法相比具有下列特点;第一,在构造过程中不需要用到矩阵的乘法运算,没有左、右Ｐａｄｅ逼近的区别,从而拓宽了应用范围．第二,它对奇异矩阵是适用的．同时,它可以用两种不同的格式计算出来：（１）分母多项式的显式行列式公式;…     

Facet模型中离散正交多项式集的递推算法

１引言Ｆａｃｅｔ是文献［１］中提出的一种图像模型,通常用它作边缘检测［２］等．它是用Ｃｈｅｂｙｓｈｅｖ离散正交多项式集作为基底函数,对以某一点为中心的对称区域内的观测图像曲面作最佳拟合,根据某个假设检验统计量的分布和预先设定的置信门限,计算估计值与观...     

求解变量带简单界约束的非线性规划问题的障碍函数法

１．引言及算法本文考虑变量带简单界约束的非线性规划问题：．问题（Ｉ）不仅是实际应用中出现的简单界约束最优化问题,而且相当一部分最优化问题可以把变量限制在有意义的区间［１］,因此无论在理论方面还是在实际应用方面,都有必要研究此类问题,给出简便而有效的算法．设ｆ是凸函数,则由Ｋ－Ｔ条件,（１）等价于求解下面的非光滑方程组：其中,以Ｘ）＝Ｖ八。）为梯度．对于由上式定义的非光滑函数用Ｘ）,定义它的模函数ｅ（。）一Ｉｓ（叫Ｉ：／ｚ．显然,６（。）是非负的,其零点是（２）的精确解．６（。）一般不是Ｆ可微的,…     

一种新的基于记忆的归纳学习算法

一种新的基于记忆的归纳学习算法王正欧，林燕（天津大学系统工程研究所天津３０００７２）关键词基于记忆的推理，归纳学习，不相似量度，分类树．１引言归纳学习是一种研究得较多的机器学习算法，其中Ｍｉｃｈａｌｓｋｉ的方法［１］是有代表性的．但正如文［２］中指出...     

一个m维整数瓶颈运输问题及其算法

５１．引言 整数瓶颈问题 （ＩＢＰ的研究最早可追朔到 １９５９年Ｇｒｏｓｓ关于瓶颈指派问题 （ＢＡＰ的研究［’］以及 Ｂａｒｓｏｗ关于时间运输问题（ＴＴＰ）的研究［’］．对 ＢＡＰ相继又出现了改进算法［３］、图算法［４］以及将其化为一般指派问题的算法［’］． １９６９年以来， Ｈａｍｍｅｒ等人又研究了 ＴＴＰ［６－８１．近十几年来，对 ＩＢＰ仍有一些新成果面世 ［９－１５１．但无论国内或者国外，所有成果其目标函数均局限在１，２维的简单情形．本文提出并研究了目标函数为。维的整数瓶颈运输问题， ５２．问题的提出…     

R-循环分块矩阵求逆的快速傅里叶算法

§１．引言 循环矩阵及循环系统的求解在线性预测、误差控制码、自回归滤波器设计领域内起着重要的作用［１－３］．而循环分块矩阵在计算机时序分析、自回归时序模型波滤中也经常出现 ［４］,文［５］对循环矩阵与循环分块矩阵作了较全面和深刻的研究．对这类矩阵求逆问题的快速算法早就引起了人们的重视［５－７］．本文试图对Ｒ－循环分块矩阵［８］求逆进行研究,提供了一种快速傅里叶算法,其计算复杂性为 Ｏ（ｍｎｌｏｇ２ｍｎ）． §２．引理和算法推导 定义１．具有如下形式的ｎ阶矩阵称为ｒ－循环矩阵,记作ＡＣｉｒｃｒ（ａ０,…     

循环三对角线性方程组的一种分布式并行算法

１．引 言 循环三对角线性方程组的求解是诸多应用问题的重要组成部分．例如,周期的样条插值就导致对角占优的循环三对角线性方程组的求解［１］,当边界条件为周期边界条件时,一些偏微分方程的离散化也可能导致循环三对角线性方程组的求解．适应计算机体系结构发展的此类方程组的算法研究,是数值并行算法的重要问题之一．文献［２］讨论了适用于共享主存并行机的此类方程组的并行算法,在 Ｍｌｌｅｒ和 Ｓｃｈｅｅｒｅｒ［３］提出的并行化Ｈ对角线性方程组解法的划分方法基础上,Ｃｈｕｎｇ［４］等对循环块三对角线性方程组进行了研究…     

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.