聚类取样

词组短语

cluster sampling

与聚类取样相关的网络例句 [注：此内容来源于网络，仅供参考]

The effects on core collection development with different sample proportionsDuring core collection development a difficult task comes when attempting to reduce the sample size of a large collection without losing its diversity.

不同聚类方法和取样策略的评价聚类方法与核心库的构建有着密切关系，不同的聚类方法对稻米品质性状核心种质的构建可以产生不同影响。

In order to overcome the technological difficulties encountered in the course of insulation fault diagnosis on the base of dissolved gases analysis, several kinds of mathematic models and actualized methods are brought forward to improve the reliability and veracity of fault diagnosis of transformers. The research works are shown mainly as followings:1 A modified fuzzy multi-criteria method is brought forward for insulation fault diagnosis of transformer. Furthermore, a new method for insulation fault diagnosis is proposed on the base of fuzzy multi-criteria together with rule reasoning. With fuzzy diagnosis in the method, fault reasons are filtrated and then the reasons in low probability are prohibited, Moreover, the left reasons are testified by using rule reasoning and then final concludes are drawn in much less misjudge probability and better results.2 On the base of geometry characteristics of C- partition to sample set of DGA data of transformer, a method is put forward to compute effective radius of neighbor field of a sample, number of clusters and values of initial centers. Moreover, the fuzzy C- means cluster model with adaptive weight is brought forward in the first time and then the fault classifier is designed for insulation fault diagnosis of transformer.3 According to the weakness of the degree of gray of gray incidence, a new formula to compute DGI is put forward and then incidence order criterion is ascertained. Moreover, a new DGI model for fault diagnosis is proposed according to the further analysis to relationship between fault reason and content of oil dissolved gases of transformer.

为解决在应用油中溶解气体分析方法（Dissolved Gases Analysis，简称DGA）诊断变压器内部绝缘故障时所遇到的主要技术难题，论文提出了用于提高变压器故障诊断准确性和可靠性的数学模型及实现方法，主要研究工作如下：1）提出了一种改进的变压器绝缘故障诊断模糊综合评判方法；进一步提出了将模糊综合诊断与规则推理相结合进行绝缘故障诊断的方法，该方法采用模糊推理对故障原因进行"过滤"，滤掉可能性极小的原因，然后进一步利用规则推理验证剩下的可能原因，得出最终结论，大大减少了误判比率，获得了较好的效果。2）根据以变压器DGA数据为特征量的样本空间的c-划分几何特性出发，提出了一种求取样本有效邻域半径和聚类数及聚类中心初值的方法，在此基础上，首次提出了一种自适应加权的变压器绝缘故障诊断的模糊c-均值聚类模型，并设计出故障分类器。3）针对常用灰色关联度的不足，提出了一新的灰色关联度计算公式及确定关联序的准则；并在此基础上，通过深入分析变压器发生绝缘故障时的原因与油中溶解特征气体含量的关系，建立了一种新的故障诊断灰色关联模型；通过实例分析证明，该方法能有效地诊断出变压器绝缘故障及故障部位，大大提高了诊断的准确性。

It also acquires the lower and upper approximation regions of all clustering kernels based on rough set theory,and achieves the explicit object-dividing method by means of their neighborhood system.

依据对象聚类邻域确定聚类数量和聚类核，以及对象的粗糙近似划分，使得聚类具有密度自适应和孤点不敏感的特点，取样分析有效提高了算法效率。

Eight hierarchical clustering methods including single linkage method, complete linkage method, median linkage method, centroid method, unweighted pair-group average method, Wards method, flexible-beta method and weighted pair-group average method were combined with three sampling strategies, random, preferred and deviation sampling to develop 24-core collections.

川最短距离法、最长距离法、中间距离法、重心法、不加权类平均法、离差平方和法、可变法和加权配对算术平均法等8种系统聚类方法，结合随机取样法、优先取样法和变异度取样法等3种取样方法，发展了24个水稻核心种质库。

The families Cercidiphyllaceae, Daphniphyllaceae, Hamamelidaceae and Saxifragaceae are closely located, while the relationships among them remain unsolved even if more repres...

尽管增加了金缕梅科的取样密度，它们之间进一步的关系仍未得到分辨，结合它们的形态特征，连香树科和交让木科应置于金缕梅目内。rbcL基因树上反映出传统的&低等&金缕梅类成员领春木科与毛茛类植物聚在一起；悬铃木科与昆栏树科和水青树科关系较近，而与金缕梅科关系较远；杜仲科与低等金缕类的核心科———金缕梅科的关系似乎较除连香树科之外的其它低等金缕类成员近。低等金缕类植物由一些古老、孤立的科组成，且是多系的。

The six groups classified by cluster analysis of SSR markers is consistent with the available pedigree and the result of combining ability. So it is feasible to analyze the genetic diversity of maize population by SSR markers and to distinguish heterotic group by method of mixed sampling.

6个玉米群体的聚类结果与系谱来源和田间配合力测定结果基本一致，说明，用若干单株混合取样分析玉米群体SSR的遗传多样性，进而对不同玉米群体划分杂种优势类群是可行的。

When 20% accessions were selected, Mahalanobis distance and Ward's method using stepwise clustering combining with preferred sampling can construct a most reprehensive core collection and was the most suitable method for constructing M. sieversii core collection.

本研究显示，当取样比例为20%时，采用马氏距离，利用离差平法和法进行多次聚类，结合优先取样策略构建的核心种质最有代表性，是构建新疆野苹果的最佳的方法。

The resistance level of German cockroach from different sites was analyzed by average linkage method.

比较德国小蠊对7种杀虫剂的抗性程度差别；比较8个取样点德国小蠊种群的抗性差别，并以类平均法做聚类分析。