Hilbert K-模上的基向量     

董芳芳  孟彬  付焕坤 《西安文理学院学报》2010,13(3):12-14

主要引入了Hilbert K-模上的Hilbert基向量,Riesz基向量,以及标准正交基向量等一系列概念,运用泛函分析和算子代数的理论知识研究了这几种向量之间的关系,得到了一些有用的结论.  相似文献   

Web文本挖掘研究     

吴育芳  陆春华 《晋图学刊》2010,(3):34-36,49

本文在介绍了Web挖掘的基础上,重点分析了Web文本挖掘的概念、过程及其关键技术,包括文本的特征表示与提取、文本的分类与聚类等。  相似文献   

空间数据索引结构及聚类方法     

杨增芳 《玉溪师范学院学报》2002,18(5):106-108

聚类是空间数据挖掘的主要技术之一 ,目前空间数据库的应用日益广泛 ,但空间数据有许多不同于关系数据库的特征。所以把已有的聚类算法应用到大型空间数据库中有许多缺点 ,且效率很低。因此必须借助高效的索引技术来提高空间数据的处理效率。  相似文献   

基于聚类协同过滤的个性化推荐系统     

程淑玉 《宜宾师范高等专科学校学报》2013,(6):82-85

个性化推荐系统被越来越多地应用到各类网站中,以解决信息增长带来的信息迷失和信息过栽问题,而协同过滤算法是个性化推荐系统的重要算法之一,但是传统的协同过滤算法存在数据稀疏、冷启动等问题,为了解决这些问题,在综合WEB日志挖掘和聚类两个因素基础上,提出基于WEB日志和聚类的协同过滤算法,并将该算法与传统的协同过滤算法进行分析比较,验证了该算法能够提高推荐的精确度和实时性．  相似文献   

半监督聚类在入侵检测中的应用研究     

周志平  庄金莲  陈佳丽 《南平师专学报》2013,(5):56-60

随着网络的快速发展,入侵检测系统生成的告警信息越来越多,聚类技术广泛的应用于处理告警信息.针对传统的K-Means算法易陷入局部最优,提出一种改进半监督聚类算法ISC.从数据集中抽取若干正常与异常样本分别采用层次聚类算法分别计算作为初始质心辅助K-Means算法进行聚类.实验结果表明,与现有相关算法相比,该算法具有更高的攻击检测率以及更低的误报率.  相似文献   

Adult students' achievement goal orientations and evaluations of the learning environment: a person-centred longitudinal analysis     

Antti-Tuomas Pulkka  Markku Niemivirta 《Educational Research and Evaluation》2013,19(4):297-322

This study focused on the stability and change in students' achievement goal orientations and whether the students' perceptions of the learning environment vary as a function of their achievement goal orientations. Participants were 169 students of the Finnish National Defense University. The students' goal orientations and their evaluations of the learning environment were assessed twice, approximately four months apart. Four groups of students were identified based on their achievement goal orientation profiles, and 60% of the participants displayed identical profiles in both measurements. Students with different goal orientation profiles differed in their evaluations of the quality of pedagogical materials, effort and attainment, and participation. Students oriented towards an increase of competence and mastery or towards normative performance and success were most positive in their evaluations. Students oriented towards avoidance of effort or display of incompetence gave less positive ratings. The relation between motivation and perceptions of learning environment is discussed.  相似文献   

判定局部共形Khler流形为Vaisman流形的若干定理     

杨永举  王学强 《南阳师范学院学报》2013,(6):5-7

利用覆盖映射和局部共形Khler流形理论,证明了满足某些条件的局部共形Khler流形一定为Vaisman流形的若干定理.如:Lee向量场为一个群S(eit,t∈R)作用诱导下的向量场一定为Vaisman流形.同时文中也给出判断Vaisman流形的若干充要条件.  相似文献   

Growth Mixture Models Outperform Simpler Clustering Algorithms When Detecting Longitudinal Heterogeneity,Even With Small Sample Sizes     

Daniel P. Martin  Timo von Oertzen 《Structural equation modeling》2013,20(2):264-275

The expansion in the number of people entering higher education has resulted in a substantial increase in the proportion of students enrolling in nontraditional modes, such as part-time study. This study examined the question of whether part-time study curtails the development of the types of intellectual capabilities needed for a knowledge-based economy, because the students would have markedly less exposure to a stimulating campus environment than their full-time counterparts. Graduates from discrete full- and part-time programs from 1 university in Hong Kong completed a survey seeking perceptions of the nurturing of a range of capabilities, together with measures of teacher-student relationships and type of teaching experienced. Two hypotheses were tested by structural equation modeling: (a) the same mechanism for capability development operated for full- and part-time modes and (b) the principal element of the mechanism was the nature of teaching and the quality of teacher-student interaction. Hypothesis 1 was supported because configural invariance between hypothesized models for capability development between the 2 modes was found. Hypothesis 2 was also supported because the models showed that the principal influence on capability development came from teaching for understanding, through promoting active learning experiences and the degree and quality of teacher-student interaction.  相似文献   

大学生数学史教育现状的灰色模糊评价模型     

徐婷 《海南广播电视大学学报》2013,(1):149-154

采用灰色模糊聚类模型,研究大学生数学史教育现状。结果表明:学生对数学史认识比较高,掌握的数学史知识比较差,运用数学史能力更差。  相似文献   

K-means聚类算法研究   总被引：2，自引：0，他引：2  

华婷婷 《黄山高等专科学校学报》2013,(5):17-19

聚类分析是模式识别中一个重要研究领域,是一种将数据划分或分组处理的重要手段和方法.K-means算法是聚类算法中主要算法之一,文章介绍了K-means聚类算法的实现方法,并对其优点和缺点进行了详细的分析.  相似文献