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   274篇
  免费   2篇
管理学   40篇
民族学   1篇
人口学   11篇
丛书文集   1篇
理论方法论   22篇
综合类   3篇
社会学   118篇
统计学   80篇
  2021年   1篇
  2020年   5篇
  2019年   3篇
  2018年   10篇
  2017年   5篇
  2016年   8篇
  2015年   8篇
  2014年   5篇
  2013年   66篇
  2012年   8篇
  2011年   9篇
  2010年   4篇
  2009年   5篇
  2008年   5篇
  2007年   9篇
  2006年   7篇
  2005年   5篇
  2004年   6篇
  2003年   7篇
  2002年   11篇
  2001年   8篇
  2000年   5篇
  1999年   2篇
  1998年   3篇
  1997年   4篇
  1996年   5篇
  1995年   3篇
  1994年   3篇
  1993年   2篇
  1992年   4篇
  1991年   3篇
  1990年   2篇
  1989年   3篇
  1988年   5篇
  1987年   2篇
  1986年   2篇
  1985年   5篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1981年   4篇
  1980年   1篇
  1979年   1篇
  1978年   3篇
  1977年   2篇
  1976年   3篇
  1973年   3篇
  1970年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有276条查询结果,搜索用时 0 毫秒
1.
2.
"The study compares determinants of internal and international migration intentions, drawing upon interview data from a sample of adults in Ilocos Norte, a largely rural province in the Philippines. A regression model is applied to test the relative determinants of intentions to migrate to Manila and to Hawaii. The study is based on a value-expectancy model of migration decision making. The results document the importance of subjective expectations related to the attainment of different values and goals in Manila and Hawaii."  相似文献   
3.
4.
To provide effective managerial support for decisions related to production planning and scheduling processes, it is useful to partition the set of decisions into a hierarchical framework. In the resulting system, higher level decisions impose constraints on lower level actions, and lower level decisions provide the necessary feed-back to reevaluate higher level actions. The purpose of this paper is to suggest optimum procedures to deal with the resulting subproblems and to analyze the interaction mechanisms among the different hierarchical levels. Computational results are given.  相似文献   
5.
As life expectancy increases, the role of grandparent has increased in duration and is continually adapting as families change in structure, function and form. Across the past several decades, researchers have examined grandparenting styles, finding some consistency as well as the emergence of newer styles, and evidence that grandparenting styles are related to the age and gender of both the grandparents and the grandchildren. In this study, we investigated young adults’ perceptions of grandparenting quality. University Students (N?=?470) from a Midwestern university responded to an online survey that asked them to evaluate the quality of their grandparents grandparenting now and at two retrospective points in time, childhood and adolescence. We hypothesized that the grandparents' performance of multiple styles of their role would be related to grandparenting quality. In addition, we expected that preferred grandparental roles would vary in relation to grandchildren's gender. The results of regression analysis indicated that, although grandparenting quality tended to decline across the respondents' developmental stages, higher ratings at an earlier stage were related to higher ratings at the latter two stages. Further, grandsons preferred grandparents who performed as supporters and advisors, whereas granddaughters preferred grandparents who functioned as supporter and friend. Overall, grandmothers were likely to be the more significant grandparent. Continual research on both grandchildren and grandparents will be needed to chronicle the development of the grandparental role in changing times.  相似文献   
6.
The paper entitled “Bivariate and Multivariate Normal Characterizations: A Brief Survey,” by Hamedani, which was published in 1992, covered the published characterizations of bivariate and multivariate normal (MVN) distributions from 1941 to 1991. The present work is a follow-up to the 1991/1992 survey which includes not only characterizations of the bivariate and MVN distributions, but also characterizations of the matrix variate normal distribution, which have appeared from 1991/1992 to the present.  相似文献   
7.
Weighted distributions (univariate and bivariate) have received widespread attention over the last two decades because of their flexibility for analyzing skewed data. In this article, we propose an alternative method to construct a new family of bivariate and multivariate weighted distributions. For illustrative purposes, some examples of the proposed method are presented. Several structural properties of the bivariate weighted distributions including marginal distributions together with distributions of the minimum and maximum, evaluation of the reliability parameter, and verification of total positivity of order two are also presented. In addition, we provide some multivariate extensions of the proposed models. A real-life data set is used to show the applicability of these bivariate weighted distributions.  相似文献   
8.
In this article we discuss various strategies for constructing bivariate Kumaraswamy distributions. As alternatives to the Nadarajah et al. (2011) bivariate model, four different models are introduced utilizing a conditional specification approach, a conditional survival function approach, and an Arnold–Ng bivariate beta distribution construction approach. Distributional properties for such bivariate distributions are investigated. Parameter estimation strategies for the models are discussed, as are the consequences of fitting two of the models to a particular data set involving the proportion of foggy days at two different airports in Colombia.  相似文献   
9.
10.

We address the testing problem of proportional hazards in the two-sample survival setting allowing right censoring, i.e., we check whether the famous Cox model is underlying. Although there are many test proposals for this problem, only a few papers suggest how to improve the performance for small sample sizes. In this paper, we do exactly this by carrying out our test as a permutation as well as a wild bootstrap test. The asymptotic properties of our test, namely asymptotic exactness under the null and consistency, can be transferred to both resampling versions. Various simulations for small sample sizes reveal an actual improvement of the empirical size and a reasonable power performance when using the resampling versions. Moreover, the resampling tests perform better than the existing tests of Gill and Schumacher and Grambsch and Therneau . The tests’ practical applicability is illustrated by discussing real data examples.

  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