共查询到20条相似文献，搜索用时 78 毫秒
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根据灰色系统基本原理和聚类分析法,用灰色聚类分析对院海铁路郑州-圃田段断面土壤重金属进行综合评价.此法先确定灰类白化函数,引入修正系数修正,避免分级标准值的误判.同时对污染物实测值进行合理权重处理.灰色聚类结果表明:得出重金属污染综合评价结果与实际污染状况基本一致,说明运用灰色聚类法是一种适用于土壤污染综合评价的科学方法. 相似文献
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通过灰色聚类评价模型这一数学媒介,可以解决公路工程造价控制中造价风险的评价问题。基于该数学模型的评价原理,以某公路项目为例,构建了公路工程造价风险评价指标体系。运用层次分析法（AHP法）和灰色聚类方法进行公路工程造价风险灰色评价,证明了该方法在此类风险评价中的可行性与可操作性。 相似文献
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利用灰色理论对班级管理质量进行灰色聚类评估，为评价班级管理质量好坏标准提供了一种切实可行的科学方法. 相似文献
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在剖析图书馆组织特征的基础上,分析了决定评价图书馆管理机制绩效的要素,建立图书馆管理绩效的评价指标体系,运用灰色理论中的灰色聚类评价法,对参与评比的三个图书馆分馆L1、L2、L3进行排序,取得较好的效果,从实例应用说明这种评价方法的有效性。 相似文献
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教师课堂教学质量评价的灰色聚类决策方法 总被引：4，自引：0，他引：4
本文将灰色聚类决策方法应用于教师课堂教学质量评价,给出教学质量状态的灰色分类,定义灰类的白化权函数,建立评价模型,对教师教学质量评价实例进行计算,并与模糊聚类方法对比.结果表明,模糊聚类具有不确定性,教学质量状态不明确;灰色聚类评价直观可靠,可以为教学管理部门的科学决策提供依据. 相似文献
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利用灰色理论对班级管理质量进行灰色聚类评估，为评价班级管理质量好坏标准提供了一种切实可行的科学方法。 相似文献
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王国胜冉治霖黄奕崇朱艳茹涂桂娥 《深圳信息职业技术学院学报》2015,(1):63-67
对灰色聚类法进行改进,引入正态分布白化权函数。白化权函数改进为曲边梯形结构可有效解决边缘零权重问题。应用改进后的灰色聚类模型对粤港珠江三角洲区域2006-2013年大气环境质量进行评价,聚类结果表明研究区域大气质量总体上逐渐提高,均为Ⅱ类。改进后的灰色聚类法评价结果客观、准确。 相似文献
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《湘南学院学报》2020,(2):53-58
物流发展与社会经济发展紧密联系,评价区域物流能力对促进社会经济发展具有重要意义.首先参考文献方法确定初级评价指标体系,然后根据数据的可获得性进行初步筛选,最后将灰色关联法与熵值法结合,计算差异性因数,从而优化评价指标,构建评价指标体系.利用灰色聚类方法,建立白化权函数,给出三个区间测度,再通过各区间测度的临界值对各指标进行定权,将权重与白化权函数相结合,计算聚类系数.计算结果表明区域物流能力较强的有北京、天津等13个省份;区域物流能力中等的有重庆、陕西等10个省份;区域物流能力较差的有青海、吉林等8个省份.将各省份的灰类与其实际情况进行对照分析,检验了聚类的合理性. 相似文献
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《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
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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
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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
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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Rajesh Kanoi 《海外英语》2007,(1):52
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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正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse. 相似文献
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《今日中学生》2014,(9)
正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between 相似文献
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《重庆大学学报(英文版)》2014,(2)
正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof. 相似文献