基于剪枝的约束概念格的渐进式构造算法

约束概念格是数据分析的一种有效工具,在其构造的过程中,大量的内涵之间比较操作是导致格的构造效率低下的主要原因之一。采用剪枝技术来消除构造过程中存在的冗余内涵比较,给出约束概念格渐进式构造算法PCCL。该算法利用父子节点内涵的严格单调关系,自顶向下扫描格节点,减少了新增对象属性集与原概念格节点内涵的比较次数,从而提高了约束概念格的构造效率。最后以天体光谱数据作为形式背景,实验验证了PCCL算法的正确性,且构造效率平均提高了15%以上。     

约束概念格及其构造方法

概念格是一种有效的数据分析和知识提取的形式化工具．然而，随着要处理的数据量的剧增，基于原始形式背景构造出的概念格结点数目庞大，占用大的存储空间，同时概念格结点中一些属性集形成的内涵，用户并不都感兴趣，因而从中提取用户需求知识费时．为了降低概念格构造的时空复杂性，增强实用性和针对性，首先采用谓词逻辑描述用户感兴趣的背景知识，并将背景知识引入到概念格结构中，提出了一种新的概念格：约束概念格．在此基础上，提出了基于背景知识的约束概念格构造算法CCLA．理论分析表明，该算法能有效地减少概念格的存储空间和建格时间．最后，采用恒星天体光谱数据作为形式背景，实验验证了该算法的有效性．     

基于属性消减的模糊概念格渐进式构造算法

当前模糊概念格的直接构造具有指数时间复杂度,且随着真值集合L大小的增加,模糊概念格的规模变得越来越庞大。为此提出了FMBUAD算法,它能够在原有模糊概念格的基础上消去多个消减属性(冗余或者无效属性)得到新的模糊概念格,且不考虑真值集合L的大小。基于模糊概念格的基础理论证明了FMBUAD算法的正确性。该算法首先将所有概念节点内涵中的消减属性隶属度移除;然后找出模糊概念格中所有的删除节点;最后集中处理删除节点父子节点之间的偏序关系。理论证明和实验结果表明:FMBUAD算法构造L-模糊概念格具有较好的时间性能。     

基于属性的概念格快速渐进式构造算法

概念格作为形式概念分析理论中的核心数据结构,在机器学习、数据挖掘和知识发现、信息检索等领域得到了广泛的应用,概念格的构造在其应用过程中是一个主要问题.提出了采用树结构对概念格节点进行组织,研究了基于属性的概念格渐进式构造算法.概念格节点的树结构组织可以约束更新格节点和产生子格节点的搜索范围,从而可以有效地减少算法的执行时间.在随机生成的数据集上进行的实验测试表明,本算法的时间性能更优越.     

基于对象和属性交叉渐进模糊概念格生成算法

在人类的认知过程中,真实的形式背景总是模糊和不确定的,并伴随着对象和属性交叉渐增更新。在分析人类概念形成机理的基础上,提出了一种基于对象和属性交叉渐进式模糊概念格生成算法。该算法从空概念格开始,逐个地将形式背景中的对象和属性交叉插入到模糊概念格中,实现对模糊概念格的渐进式构造。实验及分析表明该算法不仅能有效地渐进式构造模糊概念格,而且解决了以往渐进式概念格生成算法,针对属性和对象交叉渐增更新需要重新构造概念格的问题。     

基于属性的相对约简格快速渐进式构造算法

相对约简格作为简化的概念格,在数据挖掘和知识发现等领域具有广泛的应用.相对约简格的构造在其应用过程中是一个主要问题.本文提出了采用树结构对相对约简格节点进行组织,研究了基于属性的相对约简格渐进式构造算法.相对约简格节点的树结构组织可以约束更新格节点、产生子格节点及新生格节点的子结点的搜索范围,从而可以有效地减少算法的执行时间.该算法不仅为相对约简格的构造提供了一种方法,还解决了在已构造好相对约简格的前提下,增加属性所带来的更新问题.在随机生成的数据集上进行的实验测试表明,本算法的时间性能更优越.     

基于属性集合幂集的区间概念格Lβα的渐进式生成算法

针对区间概念格Lβα(U, A, R)的概念外延在区间［α, β］(0≤α≤β≤1)范围内满足内涵属性的特性, 提出基于属性集合幂集的区间概念格Lβα的渐进式生成算法, 以提高区间概念格的建格效率。在格结构的生成过程中, 将节点分为不变节点、更新节点、新增节点。算法首先由属性集合幂集生成所有节点的内涵, 之后根据区间概念格中父子节点的独特性质自下而上渐进式地构造格结构。通过算法分析与实例证明了优化后的渐进式生成算法提高了建格效率。     

基于二元关系消减的概念格维护算法

针对有限空间下如何快速维护概念格的问题,提出一种消减形式背景中冗余二元关系的概念格维护算法。传统的算法删除冗余关系后需要重新构造概念格,这种方式较为费时。而所提算法能够在原始概念格的基础上直接调整得到新概念格的方法,可以处理任意位置的二元关系消减的情况。它采用自底向上广度优先方式遍历格节点,首先根据当前节点是否同时包含冗余关系对象和冗余关系属性,将当前节点分为受影响的节点和不变节点;然后根据当前节点与父子节点的外延和内涵的关系,再将受影响的节点细分为4类,即减对象节点、减属性节点、分割节点、删除节点;最后根据父子节点的类型更新边。实验结果表明,在一定程度上与传统算法相比,所提算法能够获得更好的时间性能。     

基于FP-tree和约束概念格的关联规则挖掘算法及应用研究

现有的基于频繁模式树FP-tree和概念格的规则挖掘算法在构造概念格时存在重复遍历FP-tree问题,在挖掘后件约束的规则时算法构造的概念格包含冗余结点。针对这两个问题,提出了通过遍历FP-tree生成候选概念格节点的策略,并根据候选概念格节点进一步构造规则约束条件下无冗余概念格。通过实际项目中大气腐蚀数据进行算法的应用,结果表明该算法比现有算法具有更高的挖掘效率且腐蚀规则结果对材料腐蚀现状研究具有重要指导价值。     

基于同层节点集划分的模糊概念格并行构造算法

形式概念分析理论在诸多计算机领域得到广泛应用。模糊概念格的构造仍是其在应用过程中的一个主要问题。为提高模糊概念格的构造效率,对串行算法进行并行化改造,提出模糊概念格的并行构造算法。该算法对节点进行层次划分,给出了同层节点的定义,得出同层节点构造任务相互独立的重要性质,并引入映射函数简化搜索空间的遍历,提高搜索模糊概念格的效率,并行构造模糊概念格,达到了提高构造效率的目的。实验表明该算法在面对大规模的构造任务时,具有良好的性能。     

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.