全文获取类型
收费全文 | 1396篇 |
免费 | 22篇 |
国内免费 | 1篇 |
专业分类
管理学 | 91篇 |
民族学 | 2篇 |
人口学 | 12篇 |
丛书文集 | 41篇 |
理论方法论 | 9篇 |
综合类 | 528篇 |
社会学 | 21篇 |
统计学 | 715篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 16篇 |
2019年 | 29篇 |
2018年 | 33篇 |
2017年 | 68篇 |
2016年 | 25篇 |
2015年 | 28篇 |
2014年 | 43篇 |
2013年 | 332篇 |
2012年 | 79篇 |
2011年 | 41篇 |
2010年 | 32篇 |
2009年 | 40篇 |
2008年 | 54篇 |
2007年 | 40篇 |
2006年 | 36篇 |
2005年 | 48篇 |
2004年 | 36篇 |
2003年 | 28篇 |
2002年 | 19篇 |
2001年 | 25篇 |
2000年 | 37篇 |
1999年 | 43篇 |
1998年 | 29篇 |
1997年 | 29篇 |
1996年 | 42篇 |
1995年 | 34篇 |
1994年 | 28篇 |
1993年 | 11篇 |
1992年 | 21篇 |
1991年 | 4篇 |
1990年 | 18篇 |
1989年 | 8篇 |
1988年 | 13篇 |
1987年 | 1篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 3篇 |
排序方式: 共有1419条查询结果,搜索用时 93 毫秒
121.
M.A. Ali 《统计学通讯:理论与方法》2013,42(4):1467-1473
In this article optimality of experimental design for fitting a lower-order polynomial to a higher order response function for the situation in which observations may be subject to shift in means as well as in variances is considered. It is found that Karson, Manson and Hader‘s (1969) optimum designs provide pro-tection, in some sense, against model inadequacies even when observations are subject to shift in means and variances. 相似文献
122.
We consider nonlinear and heteroscedastic autoregressive models whose residuals are martingale increments with conditional distributions that fulfil certain constraints. We treat two classes of constraints: residuals depending on the past through some function of the past observations only, and residuals that are invariant under some finite group of transformations. We determine the efficient influence function for estimators of the autoregressive parameter in such models, calculate variance bounds, discuss information gains, and suggest how to construct efficient estimators. Without constraints, efficient estimators can be given by weighted least squares estimators. With the constraints considered here, efficient estimators are obtained differently, as one-step improvements of some initial estimator, similarly as in autoregressive models with independent increments. 相似文献
123.
Andrews and Phillips (1986) gave a simplified proof for the result that established the nonnegative definiteness of the difference of the Moore-Penrose inverses of two nonoegative definite matrices, a result originally due to Milliken and Akdeniz (1977), The purpose of this paper is to offer a simple proof for a generalization of this result, 相似文献
124.
In this paper, we study the class of inflated modified power series distributions (IMPSD) where inflation occurs at any of the support points. This class include among other the generalized Poisson, the generalized negative binomial, the generalized logarithmic series and the lost games distributions. We give expressions for the moments, factorial moments and central moments of the IMPSD. The maximum likelihood estimation of the parameters of the IMPSD and the variance – covariance matrix of the estimators is obtained. We derive these estimators and their information matrices for mentioned above particular members of IMPSD class. The second part of this paper deals with the distribution of sum of independent and identically distributed random variables taking values s, s+1. s + 2, …, s ≥ 0, with modified power series distributions inflated at the point s. 相似文献
125.
Two often-quoted necessary and sufficient conditions for ordinary least squares estimators to be best linear unbiased estimators are described. Another necessary and sufficient condition is described, providing an additional tool for checking to see whether the covariance matrix of a given linear model is such that the ordinary least squares estimator is also the best linear unbiased estimator. The new condition is used to show that one of the two published conditions is only a sufficient condition. 相似文献
126.
《Journal of Statistical Computation and Simulation》2012,82(10):1233-1246
Using a new approach based on Meijer G-functions and computer simulation, we numerically compute the exact null distribution of the modified-likelihood ratio statistic used to test the hypothesis that several covariances matrices of normal distributions are equal. Small samples of different sizes are considered, and for the case of two matrices, we introduce a new test based on determinants, with the null distribution of its criterion also fully computable. Comparisons with published results show the accuracy of our approach, which is proved to be more flexible and adaptable to different cases. 相似文献
127.
Peter W.M. John 《统计学通讯:理论与方法》2013,42(6):1995-2001
Kageyama Mohan (1984) have presented three methods of constructing new incomplete block designs from balanced incomplete block designs, They raise questions about the designs which come from each of their methods, These questions are answered, Another series of group divisible designs is derived as a special case of their second method. 相似文献
128.
We present a method for estimating transmission matrices that describe the mixing and the probability of infection between age groups. Transmission matrices can be used to estimate age-dependent forces of infection in age-structured, compartmental models for the study of infectious diseases. We analyze the social network generated by the synthetic population of Portland and extract mixing patterns. Our results show that the mixing within the population consists of two groups, children and adults. Children interact most frequently with other children close to their own age, while adults interact with a wider range of age groups and the durations of typical adult contacts are shorter than typical contacts between children. Furthermore, the transmission matrix shows that children are more likely to acquire infection than adults. 相似文献
129.
杨建省 《内蒙古工业大学学报》1989,8(2):87-95
线性异或逻辑方程组现有的求解方法均不适于用计算机求解。为此,本文引入了逻辑矩阵的概念。本文对逻辑矩阵、逻辑向量系的相关性、Cramer法则等进行了理论证明或分析。 相似文献
130.
在四元数体上修正了关于矩阵迹的Bellman不等式,并利用广义酉空间的理论,证明了几个四元数阵矩阵之迹的不等式。 相似文献