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   578篇
  免费   27篇
管理学   58篇
民族学   5篇
人口学   45篇
理论方法论   52篇
综合类   4篇
社会学   280篇
统计学   161篇
  2024年   1篇
  2023年   11篇
  2022年   3篇
  2021年   4篇
  2020年   9篇
  2019年   24篇
  2018年   41篇
  2017年   50篇
  2016年   31篇
  2015年   18篇
  2014年   17篇
  2013年   94篇
  2012年   63篇
  2011年   28篇
  2010年   22篇
  2009年   22篇
  2008年   28篇
  2007年   12篇
  2006年   18篇
  2005年   12篇
  2004年   13篇
  2003年   15篇
  2002年   11篇
  2001年   2篇
  2000年   7篇
  1999年   7篇
  1998年   1篇
  1997年   2篇
  1996年   3篇
  1994年   6篇
  1993年   5篇
  1992年   4篇
  1991年   4篇
  1990年   2篇
  1989年   2篇
  1987年   2篇
  1986年   1篇
  1984年   4篇
  1983年   2篇
  1982年   1篇
  1981年   2篇
  1969年   1篇
排序方式: 共有605条查询结果,搜索用时 840 毫秒
231.
Estimation of a smooth function is considered when observations on this function added with Gaussian errors are observed. The problem is formulated as a general linear model, and a hierarchical Bayesian approach is then used to study it. Credible bands are also developed for the function. Sensitivity analysis is conducted to determine the influence of the choice of priors on hyperparameters. Finally, the methodology is illustrated using real and simulated examples where it is compared with classical cubic splines. It is also shown that our approach provides a Bayesian solution to some problems in discrete time series.  相似文献   
232.
233.
This article presents the results of a small scale study of the protective service caseload of a mid-western metropolitan area. The basic characteristics of the caseload match the national picture presented by the American Humane Association's National Study on Child Abuse and Neglect. The present study focused on the degree to which “systematic” vs. “random” forces appear to be at work in the progress of cases through the system. The overall picture is of some systematic efforts to conduct the process of referrals to community agencies but of a great deal of “randomness” in the bureaucratic closing of cases. This is a major area of concern.  相似文献   
234.
235.
Classification of high-dimensional data set is a big challenge for statistical learning and data mining algorithms. To effectively apply classification methods to high-dimensional data sets, feature selection is an indispensable pre-processing step of learning process. In this study, we consider the problem of constructing an effective feature selection and classification scheme for data set which has a small number of sample size with a large number of features. A novel feature selection approach, named four-Staged Feature Selection, has been proposed to overcome high-dimensional data classification problem by selecting informative features. The proposed method first selects candidate features with number of filtering methods which are based on different metrics, and then it applies semi-wrapper, union and voting stages, respectively, to obtain final feature subsets. Several statistical learning and data mining methods have been carried out to verify the efficiency of the selected features. In order to test the adequacy of the proposed method, 10 different microarray data sets are employed due to their high number of features and small sample size.  相似文献   
236.
Social Indicators Research - The growth of the elderly population and changes in household composition raise important questions regarding the level of well-being of the elderly in developing...  相似文献   
237.
This study aimed to identify the trajectories of breadth of participation in organized activities during childhood and to examine the predictors of membership in these trajectories (child's individual and family characteristics measured in Kindergarten). A sample of 1038 children, recruited in Kindergarten, was assessed yearly between Kindergarten and grade 4. Semiparametric group‐based modeling brought out four trajectories: the no participation group (13.5 percent), the increasing group (26.4 percent), the decreasing group (14.1 percent), and the high group (46.1 percent). Prosociality predicted membership in the no participation group, as compared with the increasing group. Social withdrawal predicted membership in the no participation group, as compared with the high group. High family income and higher maternal education predicted membership in the increasing, decreasing, and high trajectory groups, as compared with the no participation group. Higher paternal education predicted membership in the high group, as compared with the increasing group. Overall, family variables had a greater impact than individual variables on the probability that the child would participate in a broader range of organized activities.  相似文献   
238.
In this paper we introduce a wide class of integer-valued stochastic processes that allows to take into consideration, simultaneously, relevant characteristics observed in count data namely zero inflation, overdispersion and conditional heteroscedasticity. This class includes, in particular, the compound Poisson, the zero-inflated Poisson and the zero-inflated negative binomial INGARCH models, recently proposed in literature. The main probabilistic analysis of this class of processes is here developed. Precisely, first- and second-order stationarity conditions are derived, the autocorrelation function is deduced and the strict stationarity is established in a large subclass. We also analyse in a particular model the existence of higher-order moments and deduce the explicit form for the first four cumulants, as well as its skewness and kurtosis.  相似文献   
239.
The finite distributed lag models include highly correlated variables as well as lagged and unlagged values of the same variables. Some problems are faced for this model when applying the ordinary least squares (OLS) method or econometric models such as Almon and Koyck models. The primary aim of this study is to compare performances of alternative estimators to the OLS estimator defined by combining the Almon estimator with some estimators using Almon (1965) data. A simulation study with different model parameters is performed and the estimators are compared according to the root mean square error (RMSE) and prediction mean square error (PMSE).  相似文献   
240.
A federal grant was awarded to provide the Within My Reach healthy relationships curriculum to low‐income, at‐risk individuals involved with various social service agencies. The effectiveness of this curriculum was evaluated for 202 participants through measures of training and relationship outcomes pre‐, immediately post‐ and 6 months posttraining. Participants experienced high levels of training satisfaction; significant increases in knowledge, communication/conflict resolution skills, and relationship quality; as well as a trend in the reduction of relationship violence. An important implication of this research is that MFTs may broaden their service delivery to at‐risk individuals by collaborating with community agencies to adapt established relationship enhancement programs, evidence‐based tools, and principles that complement traditional couples therapy.  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