全文获取类型
收费全文 | 8188篇 |
免费 | 126篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1106篇 |
民族学 | 29篇 |
人口学 | 714篇 |
丛书文集 | 31篇 |
理论方法论 | 696篇 |
综合类 | 136篇 |
社会学 | 3675篇 |
统计学 | 1928篇 |
出版年
2020年 | 115篇 |
2019年 | 172篇 |
2018年 | 167篇 |
2017年 | 258篇 |
2016年 | 175篇 |
2015年 | 155篇 |
2014年 | 182篇 |
2013年 | 1521篇 |
2012年 | 246篇 |
2011年 | 202篇 |
2010年 | 185篇 |
2009年 | 159篇 |
2008年 | 225篇 |
2007年 | 223篇 |
2006年 | 183篇 |
2005年 | 158篇 |
2004年 | 140篇 |
2003年 | 129篇 |
2002年 | 144篇 |
2001年 | 185篇 |
2000年 | 164篇 |
1999年 | 147篇 |
1998年 | 128篇 |
1997年 | 128篇 |
1996年 | 125篇 |
1995年 | 110篇 |
1994年 | 83篇 |
1993年 | 126篇 |
1992年 | 137篇 |
1991年 | 119篇 |
1990年 | 130篇 |
1989年 | 108篇 |
1988年 | 106篇 |
1987年 | 111篇 |
1986年 | 99篇 |
1985年 | 84篇 |
1984年 | 115篇 |
1983年 | 98篇 |
1982年 | 94篇 |
1981年 | 63篇 |
1980年 | 93篇 |
1979年 | 105篇 |
1978年 | 72篇 |
1977年 | 82篇 |
1976年 | 70篇 |
1975年 | 85篇 |
1974年 | 68篇 |
1973年 | 54篇 |
1972年 | 61篇 |
1971年 | 52篇 |
排序方式: 共有8315条查询结果,搜索用时 15 毫秒
211.
Mehrotra (1997) presented an ‘;improved’ Brown and Forsythe (1974) statistic which is designed to provide a valid test of mean equality in independent groups designs when variances are heterogeneous. In particular, the usual Brown and Fosythe procedure was modified by using a Satterthwaite approximation for numerator degrees of freedom instead of the usual value of number of groups minus one. Mehrotra then, through Monte Carlo methods, demonstrated that the ‘improved’ method resulted in a robust test of significance in cases where the usual Brown and Forsythe method did not. Accordingly, this ‘improved’ procedure was recommended. We show that under conditions likely to be encountered in applied settings, that is, conditions involving heterogeneous variances as well as nonnormal data, the ‘improved’ Brown and Forsythe procedure results in depressed or inflated rates of Type I error in unbalanced designs. Previous findings indicate, however, that one can obtain a robust test by adopting a heteroscedastic statistic with the robust estimators, rather than the usual least squares estimators, and further improvement can be expected when critical significance values are obtained through bootstrapping methods. 相似文献
212.
Werner Hürlimann 《统计学通讯:理论与方法》2013,42(11):2535-2545
Based one some common distribution properties of the order statistics and the transformation theory by Efron(1982), we determine unified explicit general location transformations, which map the distributions of the order statistics from the Exponential, Pareto and Weibull to a standard normal distribution. This result is used to derive analytical formulas for the maximum likelihood estimators of the shape parameter of these distributions of order statistics. The presented exact method is applied to catastrophe earthquake life reinsurance. 相似文献
213.
Víctor H. Lachos Heleno Bolfarine Reinaldo B. Arellano-Valle Lourdes C. Montenegro 《统计学通讯:理论与方法》2013,42(9):1769-1786
In this article, we present EM algorithms for performing maximum likelihood estimation for three multivariate skew-normal regression models of considerable practical interest. We also consider the restricted estimation of the parameters of certain important special cases of two models. The methodology developed is applied in the analysis of longitudinal data on dental plaque and cholesterol levels. 相似文献
214.
Marvin H. J. Gruber 《统计学通讯:理论与方法》2013,42(2):180-193
Bayesian statistics is concerned with how prior information influence inferences. This article studies this problem by comparing the value of the Rao distance between prior and posterior normal distributions. Particular cases include the linear Bayes estimator, the mixed estimator, and ridge-type estimators. 相似文献
215.
Sharma (1977) and Aggarwal et al. (2006) considered non circular construction of first- and second-order balanced repeated measurements designs. Sharma et al. (2002) constructed circular first- and second-order balanced repeated measurements designs only for a class with parameters (v, p = 3n, n = v 2) and also showed its universal optimality. In this article, we consider circular construction of first- and second-order balanced repeated measurements designs and strongly balanced repeated measurements designs by using the method of cyclic shifts. Some new circular designs with parameters (v, p, n) for cases p = v, p < v and p > v are given. 相似文献
216.
217.
An inverse regression approach to analyzing quantal response assays with one quanritative independent- variable and any number of qualitative independent variables is presented. A general factorial model ror LQC- inverted relationship and methods of testing hypotheses estimating qulitative Interest are developed. This naper provides a modified method of analysis which is easier to apply than previously existing methods. 相似文献
218.
This paper considers the effects of the presence of eqmi-correlation between observations in a k-way factorial experiment, A technique to provide unbiased F-tests is also constructed. 相似文献
219.
The Cramér-Rao lower bounds for the variances of unbiased estimators based on censored data are given. Useful techniques of evaluation are then derived for these lower bounds. Examples are given to illustrate these techniques. Small-sample comparisons are made between the resulting lower bounds, the variances of the best linear unbiased estimators, and the variances of unbiased esti-mators which are based on the maximum likelihood estimators. 相似文献
220.
The mean absolute deviation (MAD) estimator has recently received a great deal of attention as applied to full-rank linear regression models. This paper provides a necessary and sufficient condition for the MAD estimator to be a non-linear estimator, in which case conditions for the variance of the MAD estimator to be larger or smaller than those for OLS are, in general, unknown. The non-linearity of the MAD estimator is examined for several two-way designs; in particular (1) randomized block design (2) two-way nested design (3) two-way classification with interaction and (4) partially balanced incomplete block design 相似文献