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划分图上的正影响数(英文)
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作者 赵伟良 赵衍才 《运筹学学报》 CSCD 北大核心 2012年第1期41-48,共8页
一个社会网络中通常包括具有正面影响和负面影响的两类人员,为了研究这个社会网络中人们之间相互影响的某些规律,引入了一个新的概念.用划分图G=(V,E),V=V+∪V^-表示这样的一个社会网络,其中V^+和V^-分别表示正面人员的集合和负面人员... 一个社会网络中通常包括具有正面影响和负面影响的两类人员,为了研究这个社会网络中人们之间相互影响的某些规律,引入了一个新的概念.用划分图G=(V,E),V=V+∪V^-表示这样的一个社会网络,其中V^+和V^-分别表示正面人员的集合和负面人员的集合.图G的一个点子集D(?)V^-被称为G的一个正影响集,若G的每个点的至少一半的邻点在D∪V^+中.G的所有正影响集的最小基数称为G的正影响数.给出G的正影响数的几个下界并证明了这些界是紧的.此外,还证明了求正影响数问题在二部图和弦图上都是NP-完全的. 展开更多
关键词 全控制 符号全控制 正影响数 社会网络
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Research on Evenness of Woollen Cashmere Yarn
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作者 徐先林 黄故 李培玲 《Journal of Donghua University(English Edition)》 EI CAS 2009年第5期522-527,共6页
Parameters influencing the evenness of the woollen cashmere yarn were analyzed, and fifty batches of yams with fineness of 38.5 tex were used to study the quality control parameters in relation to the evenness. Throug... Parameters influencing the evenness of the woollen cashmere yarn were analyzed, and fifty batches of yams with fineness of 38.5 tex were used to study the quality control parameters in relation to the evenness. Through statistical analysis, the models of yarn evenness were built. Moreover, the relationship between the evenness of spinning yarn and roving yarn was also investigated. The results showed that a positive correlation existed between them, and the mount of thin place per kilometer was the most important factor which could influence the evenness of woollen cashmere yam. The influence of the amount of neps and thick place on the yam evenness was indistinctive. The conclusions obtained would be helpful to improve the precontrol ability on yarn evenness. 展开更多
关键词 woollen cashmere yarn yarn evenness correlation
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