排序方式: 共有16条查询结果,搜索用时 15 毫秒
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孙广勇 《广东培正学院学报》2007,(1)
民国初期,以全国教育会联合会、中华职业教育社和中华教育改进社等为代表的全国性教育团体纷纷涌现并逐渐群落化。他们顺应时代的要求而产生,以不同定位满足教育界的不同需要;他们集中了教育界的优秀人物、当时著名教育家构成的群体成为社团群落的核心领导力量;他们都在不断的自我调适中找到了发挥作用的着力点,也形成了各自的特色,充分发挥了教育社团群落的社会作用。 相似文献
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Regularization and variable selection via the elastic net 总被引:2,自引:0,他引:2
Hui Zou Trevor Hastie 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2005,67(2):301-320
Summary. We propose the elastic net, a new regularization and variable selection method. Real world data and a simulation study show that the elastic net often outperforms the lasso, while enjoying a similar sparsity of representation. In addition, the elastic net encourages a grouping effect, where strongly correlated predictors tend to be in or out of the model together. The elastic net is particularly useful when the number of predictors ( p ) is much bigger than the number of observations ( n ). By contrast, the lasso is not a very satisfactory variable selection method in the p ≫ n case. An algorithm called LARS-EN is proposed for computing elastic net regularization paths efficiently, much like algorithm LARS does for the lasso. 相似文献
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阮咏梅 《宁波大学学报(人文科学版)》2010,23(1):13-18
自20世纪80年代起,台州方言在吴语中的分片问题上一直处于游移状态。文章通过台州方言内部各点与南、北部吴语进行最具代表性的语音、词汇、语法的特征项的比较,以及地理位置和历史沿革的分析,表明台州方言与南部吴语的相似度超过了北部吴语。台州方言在吴语中是应该自成一片的。如果非得对吴语进行"非南即北"的划分的话,那么,台州方言属于南部吴语为佳。 相似文献
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Guang-Hui Fu 《统计学通讯:模拟与计算》2013,42(2):205-221
In this article, we consider the problem of variable selection and estimation with the strongly correlated multi-collinear data by using grouping variable selection techniques. A new grouping variable selection method, called weight-fused elastic net(WFEN), is proposed to deal with the high dimensional collinear data. The proposed model, combined two different grouping effect mechanisms induced by the elastic net and weight-fused LASSO, respectively, can be easily unified in the frame of LASSO and computed efficiently. The performance with the simulation and real data sets shows that our method is competitive with other related methods, especially when the data present high multi-collinearity. 相似文献
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袁丽梅 《内蒙古民族大学学报(社会科学版)》2008,34(6):105-106
在日本大学学日语常遇到的一个写作内容,那就是“レポ-ト”。本文通过对日本教师“レポ-ト”教学方法的分析,探讨了我国日语课堂教学法的改革。 相似文献
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高校学报专业化、集团化发展的设想 总被引:5,自引:0,他引:5
缪小绚 《南京人口管理干部学院学报》2004,20(3):61-63
高校学报的发展在市场经济条件和现有职称评定制度下已面临多种困境。走专业化、集团化道路是高校学报与世界接轨摆脱困境的唯一途径。组建高校学报集团,可以分两步实施,国家出版行政管理部门须在组建中起到重要协调作用。 相似文献
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Mathilde Mougeot Dominique PicardKarine Tribouley 《Journal of statistical planning and inference》2013
The estimation problem in a high regression model with structured sparsity is investigated. An algorithm using a two-step block thresholding procedure called GR-LOL is provided. Convergence rates are produced: they depend on simple coherence-type indices of the Gram matrix – easily checkable on the data – as well as sparsity assumptions of the model parameters measured by a combination of l1 within-blocks with lq, q<1 between-blocks norms. The simplicity of the coherence indicator suggests ways to optimize the rates of convergence when the group structure is not naturally given by the problem or is unknown. In such a case, an auto-driven procedure is provided to determine the regressor groups (number and contents). An intensive practical study compares our grouping methods with the standard LOL algorithm. We prove that the grouping rarely deteriorates the results but can improve them very significantly. GR-LOL is also compared with group-Lasso procedures and exhibits a very encouraging behavior. The results are quite impressive, especially when GR-LOL algorithm is combined with a grouping pre-processing. 相似文献
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产业集群是市场经济条件下工业化进行到一定阶段后的必然产物,是现阶段产业竞争力的重要来源和集中体现。由于集群内产业结构趋同,企业关联效应弱,区内支持性产业发展不健全,具有地方特色的集群文化建设滞后,创新能力不强,西部工业在全国处于弱势竞争地位。确立地方产业集群增长战略,通过政府的引导促使当地关联企业走向产业集群的路径对提升西部工业竞争,加快推进其工业化进程是一项既现实又具有重要意义的课题。 相似文献