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排序方式: 共有423条查询结果,搜索用时 15 毫秒
61.
62.
高梁分子遗传图谱研究进展 总被引:1,自引:0,他引:1
詹秋文 《安徽科技学院学报》2005,19(6):12-17
本文从临时性作图群体和永久性作图群体两方面概述了高粱分子标记遗传图谱的研究进展,比较了不同分子标记和不同作图群体在高粱图谱构建上的差异,展望了高粱遗传图谱的研究方向. 相似文献
63.
讨论了基于WindowsCE嵌入式电子地图环境的适合于嵌入式环境的电子地图匹配算法。以点、点匹配到附近的一条道路的距离和点一定区域内道路的转向角来定位实现匹配算法,并给出了相应的实验结果。 相似文献
64.
Uffe Thomas Jankvist 《Educational Studies in Mathematics》2009,71(3):235-261
This is a theoretical article proposing a way of organizing and structuring the discussion of why and how to use the history
of mathematics in the teaching and learning of mathematics, as well as the interrelations between the arguments for using
history and the approaches to doing so. The way of going about this is to propose two sets of categories in which to place
the arguments for using history (the “whys”) and the different approaches to doing this (the “hows”). The arguments for using
history are divided into two categories; history as a tool and history as a goal. The ways of using history are placed into
three categories of approaches: the illumination, the modules, and the history-based approaches. This categorization, along
with a discussion of the motivation for using history being one concerned with either the inner issues (in-issues) or the
metaperspective issues (meta-issues) of mathematics, provides a means of ordering the discussion of “whys” and “hows.”
相似文献
Uffe Thomas JankvistEmail: |
65.
刘林东 《广东教育学院学报》2010,30(3):75-79
给出智能组卷数据模型,采用遗传算法中编码、初始群体、迭代等步骤,利用交叉概率、变异概率和适合度判断迭代的收敛性,并产生适合规则的群体.对比遗传算法及其他组卷策略,遗传算法在组卷次数及组卷时间上优于传统的组卷策略. 相似文献
66.
Manuel TORAL IBAEZ Margarita CARU Miguel A.HERRERA Luis GONZALEZ Luis M.MARTIN Jorge MIRANDA Rafael M.NAVARRO-CERRILLO 《Journal of Zhejiang University. Science. B》2009,10(2)
A protocol of polymerase chain reaction-random amplified polymorphic DNAs (PCR-RAPDs) was established to analyse the gene diversity and genotype identification for clones of Sequoia sempervirens (D.Don) Endl.in Chile.Ten (out of 34) clones from introduction trial located in Voipir-Viilarrica,Chile,were studied.The PCR-RAPDs technique and a modified hexadecyltrimethylammonium bromide (CTAB) protocol were used for genomic DNA extraction.The PCR tests were carried out employing 10-mer random primers.The amplification products were detected by electrophoresis in agarose gels.Forty nine polymorphic bands were obtained with the selected primers (BG04,BF07,BF 12,BF13,and BF 14) and were ordered according to their molecular size.The genetic similarity between samples was calculated by the Jaccard index and a dendrogram was constructed using a cluster analysis of unweighted pair group method using arithmetic averages (UPGMA).Of the primers tested,5 (out of 60) RAPD primers were selected for their reproducibility and high polymorphism.A total of 49 polymorphic RAPD bands were detected out of 252 bands.The genetic similarity analysis demonstrates an extensive genetic variability between the tested clones and the dendrogram depicts the genetic relationships among the clones,suggesting a geographic relationship.The results indicate that the RAPD markers permitted the identification of the assayed clones,although they are derived from the same geographic origin. 相似文献
67.
Manuel Toral Ibañez Margarita Caru Miguel A. Herrera Luis Gonzalez Luis M. Martin Jorge Miranda Rafael M. Navarro-Cerrillo 《Journal of Zhejiang University. Science. B》2009,10(2):112-119
A protocol of polymerase chain reaction-random amplified polymorphic DNAs (PCR-RAPDs) was established to analyse the gene
diversity and genotype identification for clones of Sequoia sempervirens (D. Don) Endl. in Chile. Ten (out of 34) clones from introduction trial located in Voipir-Villarrica, Chile, were studied.
The PCR-RAPDs technique and a modified hexadecyltrimethylammonium bromide (CTAB) protocol were used for genomic DNA extraction.
The PCR tests were carried out employing 10-mer random primers. The amplification products were detected by electrophoresis
in agarose gels. Forty nine polymorphic bands were obtained with the selected primers (BG04, BF07, BF12, BF13, and BF14) and
were ordered according to their molecular size. The genetic similarity between samples was calculated by the Jaccard index
and a dendrogram was constructed using a cluster analysis of unweighted pair group method using arithmetic averages (UPGMA).
Of the primers tested, 5 (out of 60) RAPD primers were selected for their reproducibility and high polymorphism. A total of
49 polymorphic RAPD bands were detected out of 252 bands. The genetic similarity analysis demonstrates an extensive genetic
variability between the tested clones and the dendrogram depicts the genetic relationships among the clones, suggesting a
geographic relationship. The results indicate that the RAPD markers permitted the identification of the assayed clones, although
they are derived from the same geographic origin.
Project (No. CONICYT-FONDEF PROYECT D01 I 1008) supported by the National Commission of Science and Research of Chile 相似文献
68.
针对基于罚函数的排挤小生境遗传算法的缺陷,提出了改进的K-均值聚类排挤小生境遗传算法。该算法将改进的K-均值聚类分析与排挤技术有机地结合起来,无需事先确定小生境的数目和半径,可以通过调节最小聚类距离控制收敛到的小生境的数目,避免找到无效的极值点。理论分析和数值实验表明,该算法对于非均匀分布的多峰函数具有较好的搜索性能。 相似文献
69.
自动组卷系统是计算机辅助教学的重要组成部分,而遗传算法以其全局寻优和智能搜索的特性,得到了广泛的运用。根据自动组卷系统的特点,将遗传算法合理应用于自动组卷中,在遗传算法中,设计了双种群机制,并以试卷难度、试卷区分度、试卷的估计用时、知识点分布为基础构造适应度函数,通过轮盘赌选择方法、多点交叉和变异,较好地解决了自动组卷的多重目标寻优问题。 相似文献
70.
为了有效求解如何安排面试专家组成员工作使面试公正客观的问题,建立面试安排工作数学模型,该模型为复杂的非线性整数规划问题。提出一种装箱编码、模拟退火遗传、多点交叉、领域搜索变异的遗传算法对数学模型进行求解,并以一个30名专家对300名学生进行面试,且每个面试组4名专家的例子用遗传算法进行求解计算。结果表明,改进后的遗传算法能高效求解出问题的近似最优解,求解结果能满足面试工作安排所提出的要求。 相似文献