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1.
李艳  孙娜欣  赵津  王华超 《计算机科学》2011,38(11):220-224
考虑了条件属性引入优势关系而决策属性上引入等价关系的不协调目标信息系统。分析了这种基于优势-等价关系的相容约简、最大分布约简及正域约简三者之间的关系。此外,结合劣势关系抽取规则以提高规则的覆盖率,改进了基于优势关系的正域约简抽取规则(PDRIS)的方法。最后给出算例,并在UCI数据集上进行了大量的试验,以与PDRIS进行比较。  相似文献   

2.
李艳  范斌  郭劼  林梓源  赵曌 《计算机科学》2021,48(z1):342-348
基于k-原型聚类和等价关系下的粗糙集理论,对含有连续值和符号值的目标信息系统提出了一种新的适用于混合数据的属性约简方法.首先,k-原型聚类可以通过定义混合数据的距离而得到信息系统的类簇,形成对论域的划分.将所得到的类簇代替粗糙集理论中的等价类,提出基于聚类的近似集、正域以及正域约简的概念,并根据信息熵定义属性重要性度量,建立了变精度正域约简方法.这种属性约简可以同时处理数值型和符号型数据,去除其中的冗余属性,提高分类性能,降低存储和算法运行时间耗费,并通过调节聚类参数k得到对论域不同粒度的划分,对所得到的约简进行优化.最后在UCI数据集上进行了大量的实验,针对分类问题采用了常见的4种分类算法,比较了约简前后的分类精度,详细分析了参数对结果的影响,验证了约简方法的有效性.  相似文献   

3.
变精度集对势粗糙集模型   总被引:1,自引:0,他引:1  
徐怡  李龙澍 《控制与决策》2010,25(11):1732-1736
为使粗糙集理论能有效处理含噪音的不完备信息系统,将集对势扩充粗糙集模型和Ziarko教授提出的多数包含关系相结合,提出了变精度集对势粗糙集模型.然后,给出了正域相似度的定义,提出了基于正域相似度的启发式属性约简算法,并分析了算法的时间复杂度.仿真实验表明了该方法处理含噪音的不完备信息系统的有效性.  相似文献   

4.
对具有连续属性值的信息系统的属性约简是粗糙集理论的研究热点之一。区别于传统通过连续属性离散化方法定义的等价关系,提出利用自适应的模糊C均值聚类的初步划分能力定义一种相似关系以及其自适应形式。基于该相似关系定义的粗糙集模型较好地排除噪声数据。提出正域与非正域定义以及从中导出的一种重要度以指导属性约简。与现有方法的比较实验表明该方法在属性约简上具有有效性和稳定性以及约简结果的合理性。  相似文献   

5.
景运革  李天瑞 《计算机科学》2013,40(11):261-264,286
研究了粗糙集属性约简问题,引入等价关系矩阵的诱导矩阵和矩阵的λ-截矩阵等概念来计算决策表的上、下近似集,进而给出基于关系矩阵的决策表正域求解方法,并从理论上证明了该方法的正确性。提出了粗糙集属性核的启发式约简,并用该方法计算最小约简,在属性动态增加时,用矩阵快速更新的方法来改变属性等价关系矩阵,可以快速地计算属性变化后的正域。最后,通过实例分析说明了属性约简的具体操作方法和算法的有效可行性。  相似文献   

6.
针对决策信息系统属性约简问题,引入条件属性的多决策值等价类概念,给出实现属性约简的必要条件,提出一种基于多决策值等价类的属性约简算法.该算法以单个条件属性的等价类的基为升序,对条件属性进行排序,逐一选择排序后的条件属性合并,直至合并后的条件属性子集的正域为全域,进一步判断其是否独立且不可区分关系与原信息系统的不可区分关系是否相同.当条件满足时,该条件属性子集即为决策信息系统的属性约简.通过实例验证了该算法求解属性约简的有效性.  相似文献   

7.
基于(α, λ)联系度容差关系的变精度粗糙集模型   总被引:2,自引:1,他引:1  
徐怡  李龙澍 《自动化学报》2011,37(3):303-308
基于传统粗糙集理论的方法不能有效地处理含噪音的不完备信息系统. 根据集对分析理论, 提出(α, λ)联系度容差关系. 将(α, λ)联系度容差关系与Ziarko提出的多数包含关系相结合, 提出变精度(α, λ)联系度粗糙集模型. 给出了该模型下基于正域相似度的启发式属性约简算法, 分析了算法的时间复杂度, 通过仿真实验验证了所提方法处理含噪音的不完备信息系统的有效性.  相似文献   

8.
粗糙集理论是一种新的软计算方法,已成为知识发现和属性约简算法领域的一个研究热点.但经典的粗糙集理论是建立在等价关系基础之上的.从粗糙集理论出发,在优势关系之上给出了优势信息系统中信息量的概念,建立了知识粒度与信息量之间的关系.在此基础上,提出了一种基于信息量的属性约简启发式算法,得到了该算法的时间复杂性为O(|A|3×|U|2).通过实例分析表明该算法是有效的,为进一步研究约简算法提供了一种可行的方法.  相似文献   

9.
针对集值信息系统正域约简算法在大规模数据集下的运行效率问题,提出一种基于启发式的集值信息系统快速正域约简算法。通过研究属性和对象在约简过程中对算法运行效率产生的影响,在集值信息系统中引入属性无关性和属性重要度保序性的相关定义,介绍了使得算法运行效率提升的相关定理、快速算法和应用实例。通过实验对提出算法的有效性进行分析和验证。实验表明,提出算法的运行效率优于原始算法的运行效率。  相似文献   

10.
基于模糊粗糙依赖度的连续值属性约简   总被引:1,自引:0,他引:1       下载免费PDF全文
针对传统的离散化技术所造成的信息丢失问题,提出了利用模糊粗糙集理论来进行属性约简的方法。描述了模糊等价关系下的粗糙集模型,定义了正域、依赖度等概念,提出了基于模糊粗糙依赖度的属性约简算法,该方法比传统属性约简方法具有更好的时间复杂性,并用实例证明了该算法的可行性。  相似文献   

11.
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   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.  相似文献   

18.
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   

19.
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   

20.
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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