Independent component analysis via optimum combining of kurtosis and skewness-based criteria     

Juha Karvanen 《Journal of The Franklin Institute》2004,341(5):401-418

This paper introduces blind separation methods that are based on minimization of mutual information. Direct minimization of mutual information leads to estimating functions that change on every iteration of separating algorithm unlike in the maximum likelihood approach employing fixed non-linearity. We propose objective functions for source separation that are comprised of a symmetric and an asymmetric part. This allows for separating signals that may have skewed distributions. The optimal weighting between the symmetric and the asymmetric part is determined from the data based on an efficacy measure. The performance of the proposed objective functions is studied in cases where some source signals may be asymmetrically distributed. The capability of adapting to different type of source distributions is demonstrated in simulations.  相似文献   

Early Friendships: Does a Friend’s Presence in Daycare Promote Toddlers’ Prosocial Behavior Toward Peers?     

Cilly Shohet  Moran Shay  Carmit Almog-Greenberg 《Journal of Experimental Education》2019,87(3):517-529

The current study examined the effect of a friend’s presence on toddlers’ behavior in high child-to-staff-ratio daycare settings. Toddlers (N?=?38) were video-observed in the presence or absence of a verified friend in two situations that burden staff: morning separation and lunchtime (overall, 152 video observations). Higher levels of positive social engagement, fewer agonistic behaviors toward peers, and fewer occurrences of distress were observed in the friend’s presence. The duration of morning separations decreased by half and toddlers contacted the caregiver less during separations and exhibited more prosocial behaviors. Overall, toddlers demonstrated greater empathic concern when their friend was present. During lunchtime, they also displayed greater concern toward peers other than their friend. Friendship, even at a very young age, can constitute a meaningful emotional resource for soothing and security.  相似文献   

分合之道:社会学视域的方法论之争     

王建光  罗静 《甘肃高师学报》2006,11(3):114-117

考察社会学方法论的演变,几个明显的特征是:方法论个体主义和方法论整体主义;两种方法论的对立和并举;方法论整体主义和方法论个体主义的结合.  相似文献   

试析美国基础教育改革中的教育凭证制度     

章志萍 《外国教育研究》2002,29(11):37-41

目前，“择校”在西方教育改革大潮中属于热点问题，而美国基础教育改革中的教育凭证制度又是“择校”范畴中的热点。对美国教育凭证制度改革的评析有助于我们更全面地认识美国基础教育改革。  相似文献   

两类非线性波动方程的形式变量分离法求解     

郭冠平 《商丘师范学院学报》2005,21(5):18-21

利用形式变量分离法研究了两类非线性波动方程的精确解，给出了其它方法不能给出的孤波解．  相似文献   

凝胶过滤层析分离纯化纤维素酶的研究   总被引：5，自引：0，他引：5  

王玢  袁方曜 《山东教育学院学报》2003,18(6):88-90

海洋细菌MBl产生的纤维素酶粗酶液，经盐析、透析，分别上葡聚糖凝胶层析柱Sephadex G-100，Sephadex G-75和Sephadex G-50进行分离纯化。以Sephadex G-75分离效果最好，得到一个电泳纯的外切酶组分，该酶的比活力由6．94Umg^-1提高到200．9Umg^-1。提高了28．9倍，总收率8．6％。  相似文献   

数字信号处理题库和命题系统的开发     

刘焕淋  何方白 《实验技术与管理》2007,24(2):77-78,83

该文介绍了“数字信号处理试题库和命题系统”的结构和题库设置、手工组卷模块、自动命题模块和题库管理模块,该系统能够实现题库管理、试卷的手工生成和自动生成功能,可以辅助教师出试卷,促使教考分离,是提高教学质量的一个保障措施。  相似文献   

纳滤膜技术在食品及制药中的应用   总被引：3，自引：0，他引：3  

郑炳云 《福建师大福清分校学报》2002,(2):40-45

本概述了纳滤膜的特点及在影响其分离性能的各种因素，介绍了纳滤膜的分离机理及在食品和制药中的应用，并对纳滤给出简要展望。  相似文献   

水合物法分离H2+C2H4气体混合物相平衡实验研究   总被引：1，自引：0，他引：1  

李其京 《荆门职业技术学院学报》2007,22(9):6-8

采用水合物吸收法,以THF为吸收剂,进行了吸收法分离(H2 C2H4)气体混合物的相平衡实验研究。结果表明,采用THF做吸收剂可望获得很好的(H2 C2H4)气体混合物吸收分离效果。  相似文献   

七绝的乐府化及其创作风貌的变迁     

王俭 《株洲师范高等专科学校学报》2005,10(4):29-32

七绝与乐府在魏晋至盛唐期间的离合关系，表现为七绝起源时曾具民间乐府的性质(未入乐)。梁末定型后至初唐与乐府脱离，至唐开、天之际二再次结合(大量入乐)。七绝的乐府化对七绝诗体的演变、数量的激增和表现手法以及语言特色等产生了全面的影响。  相似文献