全文获取类型
收费全文 | 4620篇 |
免费 | 137篇 |
国内免费 | 17篇 |
专业分类
管理学 | 259篇 |
民族学 | 2篇 |
人口学 | 59篇 |
丛书文集 | 51篇 |
理论方法论 | 82篇 |
综合类 | 413篇 |
社会学 | 153篇 |
统计学 | 3755篇 |
出版年
2024年 | 2篇 |
2023年 | 35篇 |
2022年 | 35篇 |
2021年 | 35篇 |
2020年 | 104篇 |
2019年 | 184篇 |
2018年 | 204篇 |
2017年 | 311篇 |
2016年 | 157篇 |
2015年 | 96篇 |
2014年 | 132篇 |
2013年 | 1329篇 |
2012年 | 412篇 |
2011年 | 129篇 |
2010年 | 143篇 |
2009年 | 154篇 |
2008年 | 146篇 |
2007年 | 110篇 |
2006年 | 112篇 |
2005年 | 113篇 |
2004年 | 96篇 |
2003年 | 76篇 |
2002年 | 79篇 |
2001年 | 79篇 |
2000年 | 66篇 |
1999年 | 68篇 |
1998年 | 63篇 |
1997年 | 46篇 |
1996年 | 26篇 |
1995年 | 22篇 |
1994年 | 28篇 |
1993年 | 19篇 |
1992年 | 23篇 |
1991年 | 9篇 |
1990年 | 18篇 |
1989年 | 10篇 |
1988年 | 20篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 12篇 |
1983年 | 15篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有4774条查询结果,搜索用时 515 毫秒
571.
In this article, another version of the generalized exponential geometric distribution different to that of Silva et al. (2010) is proposed. This new three-parameter lifetime distribution with decreasing, increasing, and bathtub failure rate function is created by compounding the generalized exponential distribution of Gupta and Kundu (1999) with a geometric distribution. Some basic distributional properties, moment-generating function, rth moment, and Rényi entropy of the new distribution are studied. The model parameters are estimated by the maximum likelihood method and the asymptotic distribution of estimators is discussed. Finally, an application of the new distribution is illustrated using the two real data sets. 相似文献
572.
The Akaike Information Criterion (AIC) is developed for selecting the variables of the nested error regression model where an unobservable random effect is present. Using the idea of decomposing the likelihood into two parts of “within” and “between” analysis of variance, we derive the AIC when the number of groups is large and the ratio of the variances of the random effects and the random errors is an unknown parameter. The proposed AIC is compared, using simulation, with Mallows' C p , Akaike's AIC, and Sugiura's exact AIC. Based on the rates of selecting the true model, it is shown that the proposed AIC performs better. 相似文献
573.
Let {X j , j ≥ 1} be a strictly stationary negatively or positively associated sequence of real valued random variables with unknown distribution function F(x). On the basis of the random variables {X j , j ≥ 1}, we propose a smooth recursive kernel-type estimate of F(x), and study asymptotic bias, quadratic-mean consistency and asymptotic normality of the recursive kernel-type estimator under suitable conditions. 相似文献
574.
Hea-Jung Kim 《统计学通讯:理论与方法》2013,42(12):2136-2154
This article proposes a class of multivariate bilateral selection t distributions useful for analyzing non-normal (skewed and/or bimodal) multivariate data. The class is associated with a bilateral selection mechanism, and it is obtained from a marginal distribution of the centrally truncated multivariate t. It is flexible enough to include the multivariate t and multivariate skew-t distributions and mathematically tractable enough to account for central truncation of a hidden t variable. The class, closed under linear transformation, marginal, and conditional operations, is studied from several aspects such as shape of the probability density function, conditioning of a distribution, scale mixtures of multivariate normal, and a probabilistic representation. The relationships among these aspects are given, and various properties of the class are also discussed. Necessary theories and two applications are provided. 相似文献
575.
The Lomax (Pareto II) distribution has found wide application in a variety of fields. We analyze the second-order bias of the maximum likelihood estimators of its parameters for finite sample sizes, and show that this bias is positive. We derive an analytic bias correction which reduces the percentage bias of these estimators by one or two orders of magnitude, while simultaneously reducing relative mean squared error. Our simulations show that this performance is very similar to that of a parametric bootstrap correction based on a linear bias function. Three examples with actual data illustrate the application of our bias correction. 相似文献
576.
This article develops a procedure to obtain highly accurate confidence interval estimates for the stress-strength reliability R = P(X > Y) where X and Y are data from independent normal distributions of unknown means and variances. Our method is based on third-order likelihood analysis and is compared to the conventional first-order likelihood ratio procedure as well as the approximate methods of Reiser and Guttman (1986) and Guo and Krishnamoorthy (2004). The use of our proposed method is illustrated by an empirical example and its superior accuracy in terms of coverage probability and error rate are examined through Monte Carlo simulation studies. 相似文献
577.
In this article, we revisit the importance of the generalized jackknife in the construction of reliable semi-parametric estimates of some parameters of extreme or even rare events. The generalized jackknife statistic is applied to a minimum-variance reduced-bias estimator of a positive extreme value index—a primary parameter in statistics of extremes. A couple of refinements are proposed and a simulation study shows that these are able to achieve a lower mean square error. A real data illustration is also provided. 相似文献
578.
Y. Maleki 《统计学通讯:理论与方法》2013,42(23):4983-5004
We study locally self-similar processes (LSSPs) in Silverman’s sense. By deriving the minimum mean-square optimal kernel within Cohen’s class counterpart of time–frequency representations, we obtain an optimal estimation for the scale invariant Wigner spectrum (SIWS) of Gaussian LSSPs. The class of estimators is completely characterized in terms of kernels, so the optimal kernel minimizes the mean-square error of the estimation. We obtain the SIWS estimation for two cases: global and local, where in the local case, the kernel is allowed to vary with time and frequency. We also introduce two generalizations of LSSPs: the locally self-similar chirp process and the multicomponent LSSP, and obtain their optimal kernels. Finally, the performance and accuracy of the estimation is studied via simulation. 相似文献
579.
Ryan Martin 《统计学通讯:理论与方法》2013,42(2):286-299
An empirical Bayes problem has an unknown prior to be estimated from data. The predictive recursion (PR) algorithm provides fast nonparametric estimation of mixing distributions and is ideally suited for empirical Bayes applications. This article presents a general notion of empirical Bayes asymptotic optimality, and it is shown that PR-based procedures satisfy this property under certain conditions. As an application, the problem of in-season prediction of baseball batting averages is considered. There the PR-based empirical Bayes rule performs well in terms of prediction error and ability to capture the distribution of the latent features. 相似文献
580.
In this article, we investigate the limitations of traditional quantile function estimators and introduce a new class of quantile function estimators, namely, the semi-parametric tail-extrapolated quantile estimators, which has excellent performance for estimating the extreme tails with finite sample sizes. The smoothed bootstrap and direct density estimation via the characteristic function methods are developed for the estimation of confidence intervals. Through a comprehensive simulation study to compare the confidence interval estimations of various quantile estimators, we discuss the preferred quantile estimator in conjunction with the confidence interval estimation method to use under different circumstances. Data examples are given to illustrate the superiority of the semi-parametric tail-extrapolated quantile estimators. The new class of quantile estimators is obtained by slight modification of traditional quantile estimators, and therefore, should be specifically appealing to researchers in estimating the extreme tails. 相似文献