共查询到20条相似文献,搜索用时 62 毫秒
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基于粗糙集理论的数据清洗模型 总被引:4,自引:0,他引:4
论文在基于粗糙集理论的基础上提出一个大数据系统的数据清洗模型,以利于信息不完备决策问题的实施。模型从给定的初始数据出发,在假定属性的重要性量度σ0的前提下,经过一系列的计算,比较属性实际重要性量度σCD(x)与σ0的大小,由此确定属性x的清洗,然后根据清洗后的数据得出相应的决策规则。并给出一个简单的例子来验证数据清洗模型。 相似文献
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在实际生活中,信息系统的增量数据会不断产生,如何充分利用以前计算的结果结合新产生的数据进行新的知识发现,这是有意义的。针对这样的问题,提出了基于权得联系度的粗集模型,它着重考虑了条件属性重要性存在差异来建立粗集模型,而条件属性重要性可以通过以前数据的知识发现计算出来,于是利用基于权重联系度的粗集模型在对新产生的数据进行知识发现时,利用了以前的数据信息。建立了基于权重联系度的粗集模型及其对应的属性和属性值约简理论,最后通过一个示例来演示增量式知识发现的方法。 相似文献
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针对当前基于属性重要性的决策表属性集分解方法存在的不足,提出了一种新型的基于决策分类的决策表属性集分解方法。分析了近似分类质量和属性重要性与决策分类之间的关系,利用粗糙集理论,从提高子决策表中决策分类正确性的角度出发考虑条件属性与决策属性之间的关系,提出了决策表分解的条件属性选择量度并对决策表实施属性集分解。 相似文献
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1.用Chmbo:IkZx构件实现数据控件DBCOmboBox的功能由于Delphi的DBComIX>oc>x控件没有Text属性,使其在某些场合编程时很不方便。而普通COmb0BoX控件虽有Text属性却无DataField属性,笔者通过将已m-boBox与Query控件的配合使用,使其成为既有Text属性又包含一个数据库表字段的下拉列表框。实例:某数据库系统要求用下拉列表框对一个名单表格的“NAME”字段的内容进行选择,以便实现系统按“姓名”进行动态查询。见下表:这里我们用ComboB0x配合Qllery控件来实现上述功能的下拉列表框,具体实现方法很简单,首先用Query在… 相似文献
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数据清洗是提高数据质量的有效手段。分析了从Web上抽取的数据存在的质量问题或错误,针对错误类型,给出属性错误(包括不完整数据和异常数据)和重复与相似重复记录的描述,并提出相应的清洗方法;设计了一个数据清洗系统框架,该框架由数据预处理、数据清洗引擎和质量评估三大部分组成,可以针对不同的错误类型,完成不同的清洗任务。实验表明,该框架具有通用性和可扩展性。 相似文献
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数据仓库环境下以用户为中心的数据清洗过程模型 总被引:8,自引:1,他引:7
数据清洗是数据仓库和数据挖掘中非常重要的一个环节。本文首先分析总结了数据清洗的有关概念,给出了数据清洗中需要解决的质量问题,并总结了解决这些问题的技术和方法。在此基础上提出了以人为中心的数据清洗过程模型。该模型集成了工作流技术、数据集成、数据转换和数据挖掘技术。给出了每个工具箱应该提供的基本功能。 相似文献
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GIF图象格式以它众多的精美图象而闻名,其89a版支持一种透明属性,在许多领域得到广泛应用,如Internet中Home Page的制作,最为常见的是87a格式的GIF图象.本文介绍了一种87aGIF图象转换为89a透明图的方法.1.GIF的文件结构GIF有五个主要分量以固定顺序出现:识别标志(GIF87a或GIF89a);逻辑屏幕描述块说明了用来生成的显示文件中的图象显示器分辨率,分别表示屏幕的宽度和高;全局色表(如果存在)构成一个24位RGB三联体的调色板;位图图象数据(标志为0x2c);数据结束符(标志为0x3b).对于89a格式全局色表的后边可以存在一个图象控制扩展块或其它扩展(扩展标志为0x21),透明属性由图象控制扩展描述的. 相似文献
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S. Shaw 《Journal of Computer Assisted Learning》1993,9(2):93-99
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. 相似文献
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European Community policy and the market 总被引:1,自引:0,他引:1
C. Lloyd 《Journal of Computer Assisted Learning》1993,9(2):86-91
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. 相似文献
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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。 相似文献
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Wayne O’Brien Author Vitae 《Journal of Systems and Software》2008,81(11):1997-2013
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. 相似文献
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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. 相似文献
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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 相似文献
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David Poole 《Computational Intelligence》1989,5(2):97-110
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. 相似文献
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Watts S. Humphrey 《Annals of Software Engineering》2002,14(1-4):39-72
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. 相似文献
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基于复小波噪声方差显著修正的SAR图像去噪 总被引:4,自引:1,他引:3
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。 相似文献
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R. NOSS 《Journal of Computer Assisted Learning》1987,3(1):2-12
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. 相似文献