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1.
针对不一致决策信息系统提出了一种基于信息熵的不一致决策规则删减技术,在此基础上发展了不一致决策信息系统的属性约简算法。本算法可以有效地消除不一致信息系统中的噪声,获取一致性决策表及最优化的约简决策规则集。本算法只依赖于系统本身的性质,不需要任何外加的附加知识。  相似文献   

2.
粗集是一种处理不完整、不确定、不一致数据的数学方法,是数据压缩、数据处理、机器学习和知识挖掘的重要工具.其中约简是粗集理论的一个重要方面,通过约简,可以在保证原有分类能力不变的前提下,得到最简的分类规则,提高解决问题的效率.文章利用属性约简这一特点,对精品课程评选的评选指标进行了约简,并且导出了评选的决策规则.  相似文献   

3.
根据粗糙集理论,讨论属性值的约简方法。属性值约简是在属性约简的基础上,对决策表中的每一条记录去掉冗余属性值,从而构成一个最小的决策规则集。重点根据启发式值约简方法,对隐形眼镜数据进行分析,为后序的数据分析减少冗余信息。  相似文献   

4.
首先,在集值信息系统上定义了一种新的扩充粗糙集模型,给出了在此模型下协调集值决策信息系统的属性约简与判定准则,并通过具体事例说明了求协调集值决策信息系统约简的方法;其次,定义了不协调集值决策信息系统的分配协调集,给出了一种利用广义协调相似空间处理不协调集值信息系统的方法;最后讨论了相似水平的大小对集值决策信息系统属性约简的影响.  相似文献   

5.
Roughset理论所作的知识约简,主要是属性约简,但是,对一个增长的决策表,因为新加入的决策规则可能会与原有决策规则不相容,这样新加入一条决策规则后的知识约简可以看成是对一个增长的不相容决策表的增量式学习,本分析了作可能增量式学习的算法的复杂性和直接进行决策表约简的复杂性。  相似文献   

6.
利用标准的粗糙集方法来产生约简,即直接在原决策表的基础上计算所有的约简集,然后利用这些约简计算决策规则集合来分类未知对象。这种方法对于未知对象的分类不总是足够充分的,因为该方法没有考虑到约简集的属性部分可能是混乱、不规则的。动态约简是来自于在决策表的众多随机采样的子表中具有最大的出现频率的约简,在此意义上来说,利用动态约简来分类未知对象是最为稳定、可靠的。  相似文献   

7.
将粗糙集和神经网络方法相结合讨论了RoughSet-NN模型,运用粗糙集理论进行信息约简,获取约简规则,最后把约简规则送神经网络。探讨RoughSet-NN模型在在林业决策中的应用问题。  相似文献   

8.
文章主要介绍基于粗集方法的普通话等级判别专家系统的基本构成、知识表达方式及学习推理方法。提出了利用不可分辨性进行属性约简,导出决策规则的方法进行推理。实践证明,该专家系统具有可行性。  相似文献   

9.
文章提出了在粗糙集理论中规则提取的新方法——利用图形的匹配来提取规则.粗糙集理论在数据分类应用中的主要思想是保持分类能力不变的情况下,利用等价类,通过属性约简和决策规则约简,达到挖掘知识并简化知识的目的.  相似文献   

10.
提出了一种分类规则的蚁群挖掘算法.算法首先对所有的连续属性值离散化,得到相应的离散属性,然后让各只蚂蚁按照某种策略选择相关属性,对所选属性再选择理想的属性值,循环地构造单个规则,接着更新训练集,最终形成各类规则集.最后用新规则约简算法进行约简操作.对两个公用数据的实验及其与Ant-Miner和C4.5的对比表明,算法能够发现更好的分类规则.实验同时表明该算法是有效的.  相似文献   

11.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

12.
汉字倒说     
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。  相似文献   

13.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.  相似文献   

14.
王菲 《华章》2007,(12):273-273
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.  相似文献   

15.
裴水妹 《华章》2007,(11):196
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.  相似文献   

16.
17.
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…  相似文献   

18.
钱生钱!     
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了  相似文献   

19.
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.  相似文献   

20.
Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.  相似文献   

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