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   78篇
  免费   3篇
管理学   8篇
理论方法论   8篇
社会学   17篇
统计学   48篇
  2022年   1篇
  2020年   2篇
  2019年   2篇
  2018年   1篇
  2017年   4篇
  2016年   2篇
  2015年   3篇
  2014年   3篇
  2013年   29篇
  2012年   4篇
  2011年   4篇
  2010年   3篇
  2009年   2篇
  2008年   1篇
  2007年   4篇
  2006年   1篇
  2003年   1篇
  2001年   1篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1986年   1篇
  1984年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1975年   1篇
  1973年   1篇
排序方式: 共有81条查询结果,搜索用时 625 毫秒
61.
The recurrence relations between the incomplete moments and the factorial incomplete moments of the modified power series distributions (MPSD) are derived. These relations are employed to obtain the experessions for the incomplete moments and the incomplete factorial moments of some particular members of the MPSD class such as the generalized negative binomial, the generalized Poisson, the generalized logrithmic series, the lost game distribution and the distribution of the number of customers served in a busy period. An application of the incomplete moments of the generalized Poisson distribution is provided in the economic selection of a manufactured product. A numerical example is provided using the Poisson distribution and the Generalized Poisson distribution. The example illustrates the difference in results using the two models  相似文献   
62.
In this paper we consider the class of modified power series distribution introduced by GUPTA (1974) and derive a minimum variance unbiased estimator (MVUE) of the probability function for this class. these results are then applied to obtain MVUE of the probability function for the generalized negative binomial distributions, the generalized poisson distribution, the generalized logarithmic series distribution and the lost game distribution. A large number of results in the literature follow trivially from out results as special cases.  相似文献   
63.
In this paper, we have considered the problem of finding the distribution of a linear combination of the minimum and the maximum for a general bivariate distribution. The general results are used to obtain the required distribution in the case of bivariate normal, bivariate exponential of Arnold and Strauss, absolutely continuous bivariate exponential distribution of Block and Basu, bivariate exponential distribution of Raftery, Freund's bivariate exponential distribution and Gumbel's bivariate exponential distribution. The distributions of the minimum and maximum are obtained as special cases.  相似文献   
64.
65.
We examined whether infants organize information according to the newly proposed principle of common region, which states that elements within a region are grouped together and separated from those of other regions. In Experiment 1, 6‐ to 7‐month‐olds exhibited sensitivity to regions by discriminating between the displacement of an element within a region versus across regions. In Experiments 2 (6‐ to 7‐month‐olds) and 3 (3‐ to 4‐month‐olds), infants who were habituated to 2 elements in each of 2 regions subsequently discriminated between a familiar and novel grouping in familiar and novel regions. Thus, infants as young as 3 to 4 months of age are not only sensitive to regions in visual images, but also use these regions to group elements in accord with the principle of common region. Because common region analysis is critical to such basic visual functions as figure‐ground and object segregation, these results suggest that the organizational mechanism that underlies many vital visual functions is already operational by 3 to 4 months of age.  相似文献   
66.
67.
Categorical perception, indicated by superior discrimination between stimuli that cross categorical boundaries than between stimuli within a category, is an efficient manner of classification. The current study examined the development of categorical perception of emotional stimuli in infancy. We used morphed facial images to investigate whether infants find contrasts between emotional facial images that cross categorical boundaries to be more salient than those that do not, while matching the degree of differences in the two contrasts. Five‐month‐olds exhibited sensitivity to the categorical boundary between sadness and disgust, between happiness and surprise, as well as between sadness and anger but not between anger and disgust. Even 9‐month‐olds failed to exhibit evidence of a definitive category boundary between anger and disgust. These findings indicate the presence of discrete boundaries between some, but not all, of the basic emotions early in life. Implications of these findings for the major theories of emotion representation are discussed.  相似文献   
68.
This paper proposes a bivariate version of the univariate discrete generalized geometric distribution considered by Gómez–Déniz (2010 Gómez–Déniz, E. (2010). Another generalization of the geometric distribution. Test 19:399415.[Crossref], [Web of Science ®] [Google Scholar]). The proposed bivariate distribution can have a positive or negative correlation coefficient which can be used for modeling bivariate-dependent count data. After discussing some of its properties, maximum likelihood estimation is discussed. Two illustrative examples are given for fitting and demonstrating the usefulness of the new bivariate distribution proposed here.  相似文献   
69.
Accurate assessment of emotion requires the coordination of information from different sources such as faces, bodies, and voices. Adults readily integrate facial and bodily emotions. However, not much is known about the developmental origin of this capacity. Using a familiarization paired‐comparison procedure, 6.5‐month‐olds in the current experiments were familiarized to happy, angry, or sad emotions in faces or bodies and tested with the opposite image type portraying the familiar emotion paired with a novel emotion. Infants looked longer at the familiar emotion across faces and bodies (except when familiarized to angry images and tested on the happy/angry contrast). This matching occurred not only for emotions from different affective categories (happy, angry) but also within the negative affective category (angry, sad). Thus, 6.5‐month‐olds, like adults, integrate emotions from bodies and faces in a fairly sophisticated manner, suggesting rapid development of emotion processing early in life.  相似文献   
70.
ABSTRACT

Children in the child welfare system have entitlements to health insurance coverage—critical because of their considerable physical and mental health needs—based largely on their placement status. This study conducted path and transitions analyses on data from the National Survey of Child and Adolescent Well-Being (3,801 children followed-up for 3 years) to examine the interplay between placement changes and insurance stability. Children maintained in-home at Wave 1 had significantly lower odds of being insured (OR = 0.7); children transitioning from out-of-home placement to in-home care had significantly lower odds of maintaining insurance coverage (OR = 0.6). Child welfare workers working with children maintained in-home and those being reunified should safeguard the children's insurance status. Policy makers should consider extension of categorical eligibility to all children presenting to child welfare agencies in order to assure access to needed services for these vulnerable children.  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