首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   73篇
  免费   3篇
管理学   6篇
民族学   1篇
人口学   6篇
理论方法论   14篇
综合类   1篇
社会学   35篇
统计学   13篇
  2023年   3篇
  2022年   1篇
  2020年   8篇
  2018年   3篇
  2017年   2篇
  2016年   6篇
  2015年   1篇
  2014年   3篇
  2013年   11篇
  2012年   10篇
  2011年   5篇
  2010年   5篇
  2009年   1篇
  2008年   4篇
  2004年   1篇
  2003年   2篇
  1999年   1篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1991年   2篇
  1990年   2篇
  1984年   1篇
  1983年   1篇
排序方式: 共有76条查询结果,搜索用时 0 毫秒
71.
Port and maritime studies dealing with containerization have observed traffic concentration and dispersion throughout the world. Globalization, intermodal transportation, and technological revolutions in the shipping industry have resulted in both network extension and rationalization. However, lack of precise data on inter‐port relations prevent the application of wider network theories to global maritime container networks, which are often examined through case studies of specific firms or regions. In this article, we present an analysis of the global liner shipping network in 1996 and 2006, a period of rapid change in port hierarchies and liner service configurations. While we refer to literature on port system development, shipping networks, and port selection, the article is one of the only analyses of the properties of the global container shipping network. We analyse the relative position of ports in the global network through indicators of centrality. The results reveal a certain level of robustness in the global shipping network. While transhipment hub flows and gateway flows might slightly shift among nodes in the network, the network properties remain rather stable in terms of the main nodes polarizing the network and the overall structure of the system. In addition, mapping the changing centrality of ports confirms the impacts of global trade and logistics shifts on the port hierarchy and indicates that changes are predominantly geographic.  相似文献   
72.
Handling dependence or not in feature selection is still an open question in supervised classification issues where the number of covariates exceeds the number of observations. Some recent papers surprisingly show the superiority of naive Bayes approaches based on an obviously erroneous assumption of independence, whereas others recommend to infer on the dependence structure in order to decorrelate the selection statistics. In the classical linear discriminant analysis (LDA) framework, the present paper first highlights the impact of dependence in terms of instability of feature selection. A second objective is to revisit the above issue using a flexible factor modeling for the covariance. This framework introduces latent components of dependence, conditionally on which a new Bayes consistency is defined. A procedure is then proposed for the joint estimation of the expectation and variance parameters of the model. The present method is compared to recent regularized diagonal discriminant analysis approaches, assuming independence among features, and regularized LDA procedures, both in terms of classification performance and stability of feature selection. The proposed method is implemented in the R package FADA, freely available from the R repository CRAN.  相似文献   
73.
74.
Abstract. The strong Rayleigh property is a new and robust negative dependence property that implies negative association; in fact it implies conditional negative association closed under external fields (CNA+). Suppose that and are two families of 0‐1 random variables that satisfy the strong Rayleigh property and let . We show that {Zi} conditioned on is also strongly Rayleigh; this turns out to be an easy consequence of the results on preservation of stability of polynomials of Borcea & Brändén (Invent. Math., 177, 2009, 521–569). This entails that a number of important π ps sampling algorithms, including Sampford sampling and Pareto sampling, are CNA+. As a consequence, statistics based on such samples automatically satisfy a version of the Central Limit Theorem for triangular arrays.  相似文献   
75.
The central idea of the paper is that human thinking consists in a movement through which a person socially interacts with herself. Consequently, thinking does not offer the experience of a private refuge in the intimacy of the individual thinker's self‐knowing, but a field where multiple points of view interact by contesting, distancing, approaching, agreeing or disagreeing, one to another. Classical ( Isocrates, 1929 /1968) and contemporary (Billig, 1987) rhetorical approaches to thinking stress that both “inner” and “social” discourse are addressed to someone else, are determined by the anticipation of this audience, and both are interested in persuading it. In doing so, the discursive, rhetoric, and dialogic aspects of thinking become tied to argumentation. The paper tries to show, following the dialogical notion of discourse of Bakhtin (1986) and Volo?inov (1929/1986) that, since every act of thinking consists in the raising of a point of view addressing another one and oriented by a particular interest, every stream of thought involves a rhetorical activity. A distinction between rhetoric and argumentation is proposed. On this basis, the rhetorical nature of thinking is discussed beyond argumentative discourse. Overall, this discussion contributes to a rhetorical approach to dialogism.  相似文献   
76.
The purpose of this 5-year longitudinal study is to identify trajectories of team and individual sports participation in childhood, and to compare these trajectories on different types of internalizing problems. Parents reported their children's annual sports participation from the ages of 6–10 (n = 785) and teachers reported internalizing problems (depression, anxiety, social withdrawal) at the beginning and at the end of this period. The study used latent class growth analyses to identify two trajectories of team sports and two trajectories of individual sports participation were identified: (1) high participation, and (2) low participation. Considering baseline level of internalizing problems and gender, children in the high participation team sports trajectory show significantly fewer depression, anxiety, and social withdrawal behaviors at age 10 than those in the low participation team sports trajectory. No differences between individual sports trajectories were observed. Comparison with joint trajectory groups partially confirmed these results but also showed that sustained participation in multiple individual sports could also be linked to decreased anxiety. Our findings suggest that participation in team sports should be encouraged to promote certain aspects of children's mental health.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号