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1.
研究了含区间值的不完备复杂信息系统,其不仅包含遗漏型未知属性值,而且属性值域为全序集.根据区间值特点给出其遗漏型和填充式区间值概念,并定义了不完备序区间值决策系统;然后,提出了区间段值概念和基于区间段值的序决策系统,其中引入灰的白化方法以将填充式区间值转换为区间段值;接着,提出基于区间段值的优势和弱势描述子,用以获取序区间段值决策系统中的所有可信规则并给出具体算法步骤;最后,用实例进行了验证.试验分析的结果表明了该方法的有效性.  相似文献   

2.
现实世界中的信息决策系统是非常复杂的,许多信息表中的记录不仅是离散值,还可能为区间值。本文以包含区间值的灰色粗糙集为研究对象,使用基于区间一致关系和区间包含关系取代经典粗集模型中的等价关系和不可分别关系,给出了从含区间值灰色决策系统中获取知识新的理论基础与操作手段。  相似文献   

3.
区间值信息系统是单值信息系统的一种扩充,如何对其进行属性约简是区间值多属性决策中的一个重要的问题.在已有的优势关系基础上,定义了α-β优势关系,得到基于新的优势关系的可辨识矩阵,进而对区间值信息系统进行属性约简,给出了约简算法.最后通过一个算例验证了新方法的可行性,并与已有方法进行了比较,结果表明所提出的方法更为简单有效.  相似文献   

4.
区间值信息系统是单值信息系统的一种扩充,如何对其进行属性约简是区间值多属性决策中的一个重要的问题.在已有的优势关系基础上,定义了α-β优势关系,得到基于新的优势关系的可辨识矩阵,进而对区间值信息系统进行属性约简,给出了约简算法.最后通过一个算例验证了新方法的可行性,并与已有方法进行了比较,结果表明所提出的方法更为简单有效.  相似文献   

5.
多粒度是当前粒计算研究的一个重要方面.在实践中,人们往往选择比较合适的粒度层次来解决问题.作为信息系统的一种特殊情况,多粒度决策系统是经常使用数据表示形式.在这样的系统中,对象可以在属性的不同粒度层次上取不同的观测值.实际使用时,常常遇到在数据属性上需要比较大小,即属性带有序关系.序关系分析是多指标决策的重要内容,而粗糙集是一种处理序关系有效方法.围绕多标记序决策系统的知识获取问题来开展研究,首先,介绍了多标记序决策系统的概念;然后,在协调的多标记序决策系统中定义了最优粒度和局部最优粒度,并介绍了基于局部最优粒度的属性约简和规则获取方法;最后,在不协调的多标记序决策系统中引入了广义决策,定义了广义最优粒度和广义局部最优粒度,并给出了基于广义局部最优粒度的属性约简和规则获取方法.  相似文献   

6.
在贝叶斯可信区间估计理论基础上,借助于灰色理论研究随机信息下贝叶斯灰色可信区间的估计问题,较传统的方法能够获取更多的有效信息.  相似文献   

7.
将多粒度理论引入不完备决策系统中,针对其不完备性,结合非对称相似关系提出基于相似关系的不完备多粒度粗糙集模型,并讨论该模型的性质。随后重点讨论基于相似关系的不完备多粒度粗糙集模型中属性约简和决策规则获取的问题,将多粒度理论和近似分布约简相结合,提出了不完备多粒度近似分布约简,获得所有的最简确定决策规则和最简可能决策规则。最后通过实例分析,发现使用多粒度近似分布约简与规则获取方法比原有的单粒度近似分布约简与决策获取方法更合理有效。  相似文献   

8.
一种基于容差关系的辨识矩阵属性约简法   总被引:1,自引:0,他引:1  
为有效处理灰色信息系统的属性约简问题,将粗糙集理论中有关属性约简的方法运用到灰色信息系统中,提出了一种基于容差关系的辨识矩阵属性约简法.这种方法并不对灰数进行白化,而是直接利用灰数的区间覆盖性定义一个基于贴近度的容差关系,并根据这个容差关系建立一个辨识矩阵对属性进行约简,避免了当灰数的取值分布信息缺乏时对灰数进行白化的主观性,是一种较为客观有效的灰色信息系统的属性约简法.  相似文献   

9.
一类灰色区间聚类决策方法   总被引:2,自引:0,他引:2  
以灰色决策分析理论为基础,探讨了经典灰色聚类决策方法的优势和不足.提出了基于理想方案的灰色区间聚类方法及其相关概念,建立了灰色区间关联系数公式和灰色区间相对关联系数公式.运用分析技巧,构建了灰色区间聚类决策算法.灰色区间关联系数公式是经典灰色关联系数公式的推广,而灰色区间聚类决策是经典灰色聚类决策方法的拓展.实例说明了所提出的灰色聚类决策方法的合理性及其算法的有效性.  相似文献   

10.
针对目前诊断推理中知识库构建存在知识获取困难,提出了一种基于粗糙集和决策理论的诊断知识库构建模型.该模型引入决策技术和粗糙集理论,对源数据进行预处理,构建决策表,通过属性约简和属性值约简获取故障诊断的最小约简属性集和诊断规则,并建立诊断规则知识库.实例证明在保持故障诊断分类结果的情况下,该方法可以提取出最能反映故障的特征知识,并能有效地解决诊断知识库构建中规则获取的知识冗余或缺失问题,显著提高故障诊断的精度和效率.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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