全文获取类型
收费全文 | 3206篇 |
免费 | 75篇 |
国内免费 | 6篇 |
专业分类
管理学 | 78篇 |
民族学 | 1篇 |
人口学 | 23篇 |
丛书文集 | 8篇 |
理论方法论 | 4篇 |
综合类 | 165篇 |
社会学 | 16篇 |
统计学 | 2992篇 |
出版年
2023年 | 12篇 |
2022年 | 5篇 |
2021年 | 20篇 |
2020年 | 51篇 |
2019年 | 98篇 |
2018年 | 133篇 |
2017年 | 218篇 |
2016年 | 88篇 |
2015年 | 84篇 |
2014年 | 111篇 |
2013年 | 1208篇 |
2012年 | 277篇 |
2011年 | 69篇 |
2010年 | 87篇 |
2009年 | 74篇 |
2008年 | 82篇 |
2007年 | 65篇 |
2006年 | 57篇 |
2005年 | 66篇 |
2004年 | 45篇 |
2003年 | 47篇 |
2002年 | 46篇 |
2001年 | 38篇 |
2000年 | 31篇 |
1999年 | 39篇 |
1998年 | 46篇 |
1997年 | 26篇 |
1996年 | 20篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 15篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 15篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有3287条查询结果,搜索用时 15 毫秒
991.
Suppose that there are independent samples available from several multivariate normal populations with the same mean vector m? but possibly different covariance matrices. The problem of developing a confidence region for the common mean vector based on all the samples is considered. An exact confidence region centered at a generalized version of the well-known Graybill-Deal estimator of m? is developed, and a multiple comparison procedure based on this confidence region is outlined. Necessary percentile points for constructing the confidence region are given for the two-sample case. For more than two samples, a convenient method of approximating the percentile points is suggested. Also, a numerical example is presented to illustrate the methods. Further, for the bivariate case, the proposed confidence region and the ones based on individual samples are compared numerically with respect to their expected areas. The numerical results indicate that the new confidence region is preferable to the single-sample versions for practical use. 相似文献
992.
The article considers a Gaussian model with the mean and the variance modeled flexibly as functions of the independent variables. The estimation is carried out using a Bayesian approach that allows the identification of significant variables in the variance function, as well as averaging over all possible models in both the mean and the variance functions. The computation is carried out by a simulation method that is carefully constructed to ensure that it converges quickly and produces iterates from the posterior distribution that have low correlation. Real and simulated examples demonstrate that the proposed method works well. The method in this paper is important because (a) it produces more realistic prediction intervals than nonparametric regression estimators that assume a constant variance; (b) variable selection identifies the variables in the variance function that are important; (c) variable selection and model averaging produce more efficient prediction intervals than those obtained by regular nonparametric regression. 相似文献
993.
Distribution-Free Inference for Welfare Indices under Complete and Incomplete Information 总被引:3,自引:3,他引:0
The data available for estimating welfare indicators are often inconveniently incomplete data: they may be censored or truncated. Furthermore, for robustness reasons, researchers sometimes use trimmed samples. By using the statistical tool known as the Influence Function we derive distribution-free asymptotic variances for wide classes of welfare indicators not only in the complete data case, but also in the important cases where the data have been trimmed, censored or truncated. 相似文献
994.
Ramesh C. Gupta 《Journal of statistical planning and inference》1984,9(1):55-62
In a classical gambler's ruin problem, the distribution of the number of games lost till ruin is considered, which we call the lost game distribution (LGD). Some applications of LGD in the theory of queues, in the theory of epidemic and in certain clustering and branching models are mentioned. The maximum likelihood estimation of LGD in the framework of modified power series distribution (MPSD), introduced by the author (1974), is studied. The variance and bias of the MLE are given and the actual mean of the MLE is obtained by discussing the negative moments of the MPSD in general. The minimum variance unbiased estimator of θk (k≥1) is obtained employing the technique developed by the author (1977) for the class of MPSD. 相似文献
995.
Changbao Wu 《Revue canadienne de statistique》2004,32(1):15-26
It is often desirable to combine information collected in compatible multiple surveys in order to improve estimation and meet consistency requirements. Zieschang (1990) and Renssen & Nieuwenbroek (1997) suggested to this end the use of the generalized regression estimator with enlarged number of auxiliary variables. Unfortunately, adjusted weights associated with their approach can be negative. The author uses the notion of pseudo empirical likelihood to construct new estimators that are consistent, efficient and possess other attractive properties. The proposed approach is asymptotically equivalent to the earlier one, but it has clear maximum likelihood interpretations and its adjusted weights are always positive. The author also provides efficient algorithms for computing his estimators. 相似文献
996.
Knut Heggland Arnoldo Frigessi 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2004,66(2):447-462
Summary. There are models for which the evaluation of the likelihood is infeasible in practice. For these models the Metropolis–Hastings acceptance probability cannot be easily computed. This is the case, for instance, when only departure times from a G / G /1 queue are observed and inference on the arrival and service distributions are required. Indirect inference is a method to estimate a parameter θ in models whose likelihood function does not have an analytical closed form, but from which random samples can be drawn for fixed values of θ . First an auxiliary model is chosen whose parameter β can be directly estimated. Next, the parameters in the auxiliary model are estimated for the original data, leading to an estimate . The parameter β is also estimated by using several sampled data sets, simulated from the original model for different values of the original parameter θ . Finally, the parameter θ which leads to the best match to is chosen as the indirect inference estimate. We analyse which properties an auxiliary model should have to give satisfactory indirect inference. We look at the situation where the data are summarized in a vector statistic T , and the auxiliary model is chosen so that inference on β is drawn from T only. Under appropriate assumptions the asymptotic covariance matrix of the indirect estimators is proportional to the asymptotic covariance matrix of T and componentwise inversely proportional to the square of the derivative, with respect to θ , of the expected value of T . We discuss how these results can be used in selecting good estimating functions. We apply our findings to the queuing problem. 相似文献
997.
In dealing with ties in failure time data the mechanism by which the data are observed should be considered. If the data are discrete, the process is relatively simple and is determined by what is actually observed. With continuous data, ties are not supposed to occur, but they do because the data are grouped into intervals (even if only rounding intervals). In this case there is actually a non–identifiability problem which can only be resolved by modelling the process. Various reasonable modelling assumptions are investigated in this paper. They lead to better ways of dealing with ties between observed failure times and censoring times of different individuals. The current practice is to assume that the censoring times occur after all the failures with which they are tied. 相似文献
998.
长青 《内蒙古工业大学学报》1995,14(1):7-12
针对回归分析中自变量数据间的共线性问题,本文基于降低解释变量间相关程度的弱相关思想,构造出一个新的回归估计式。并证明了估计式与最小二乘相比,具有均方差意义下 的优良性。还证明了相对于最小二乘估计,新估计式是一种模压缩。该估计式具有意义直观明了,便于分析,应用的特性。 相似文献
999.
Exact methods for testing equality between variance components obtained from several cases of the same type of balanced orthogonal design are discussed. In particular, methods for successively testing equality of a number of components using Bartlett's tests are outlined for univariate and multivariate responses. Two clinical trial examples of repeated‐measures data are presented. 相似文献
1000.
Christine M. Anderson‐Cook Heidi B. Goldfarb Connie M. Borror Douglas C. Montgomery Kelly G. Canter John N. Twist 《Pharmaceutical statistics》2004,3(4):247-260
Many experiments in research and development in the pharmaceutical industry involve mixture components. These are experiments in which the experimental factors are the ingredients of a mixture and the response variable is a function of the relative proportion of each ingredient, not its absolute amount. Thus the mixture ingredients cannot be varied independently. A common variation of the mixture experiment occurs when there are also one or more process factors that can be varied independently of each other and of the mixture components, leading to a mixture–process variable experiment. We discuss the design and analysis of these types of experiments, using tablet formulation as an example. Our objective is to encourage greater utilization of these techniques in pharmaceutical research and development. Copyright © 2004 John Wiley & Sons Ltd. 相似文献