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   15914篇
  免费   455篇
  国内免费   184篇
管理学   1548篇
劳动科学   2篇
民族学   115篇
人才学   1篇
人口学   385篇
丛书文集   947篇
理论方法论   512篇
综合类   8457篇
社会学   1194篇
统计学   3392篇
  2024年   23篇
  2023年   140篇
  2022年   134篇
  2021年   177篇
  2020年   309篇
  2019年   367篇
  2018年   425篇
  2017年   541篇
  2016年   430篇
  2015年   504篇
  2014年   827篇
  2013年   1900篇
  2012年   1097篇
  2011年   1048篇
  2010年   853篇
  2009年   818篇
  2008年   920篇
  2007年   1007篇
  2006年   915篇
  2005年   796篇
  2004年   701篇
  2003年   587篇
  2002年   491篇
  2001年   362篇
  2000年   267篇
  1999年   159篇
  1998年   87篇
  1997年   95篇
  1996年   88篇
  1995年   67篇
  1994年   67篇
  1993年   56篇
  1992年   46篇
  1991年   25篇
  1990年   32篇
  1989年   35篇
  1988年   24篇
  1987年   26篇
  1986年   21篇
  1985年   16篇
  1984年   23篇
  1983年   12篇
  1982年   10篇
  1981年   13篇
  1980年   6篇
  1979年   2篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
A semiparametric two-component mixture model is considered, in which the distribution of one (primary) component is unknown and assumed symmetric. The distribution of the other component (admixture) is known. Generalized estimating equations are constructed for the estimation of the mixture proportion and the location parameter of the primary component. Asymptotic normality of the estimates is demonstrated and the lower bound for the asymptotic covariance matrix is obtained. An adaptive estimation technique is proposed to obtain the estimates with nearly optimal asymptotic variances.  相似文献   
142.
ABSTRACT

Harter (1979) summarized applications of order statistics to multivariate analysis up through 1949. The present paper covers the period 1950–1959. References in the two papers were selected from the first and second volumes, respectively, of the author's chronological annotated bibliography on order statistics [Harter (1978, 1983)]. Tintner (1950a) established formal relations between four special types of multivariate analysis: (1) canonical correlation, (2) principal components, (3) weighted regression, and (4) discriminant analysis, all of which depend on ordered roots of determinantal equations. During the decade 1950–1959, numerous authors contributed to distribution theory and/or computational methods for ordered roots and their applications to multivariate analysis. Test criteria for (i) multivariate analysis of variance, (ii) comparison of variance–covariance matrices, and (iii) multiple independence of groups of variates when the parent population is multivariate normal were usually derived from the likelihood ratio principle until S. N. Roy (1953) formulated the union–intersection principles on which Roy & Bose (1953) based their simultaneous test and confidence procedure. Roy & Bargmann (1958) used an alternative procedure, called the step–down procedure, in deriving a test for problem (iii), and J. Roy (1958) applied the step–down procedure to problem (i) and (ii), Various authors developed and applied distribution theory for several multivariate distributions. Advances were also made on multivariate tolerance regions [Fraser & Wormleighton (1951), Fraser (1951, 1953), Fraser & Guttman (1956), Kemperman (1956), and Somerville (1958)], a criterion for rejection of multivariate outliers [Kudô (1957)], and linear estimators, from censored samples, of parameters of multivariate normal populations [Watterson (1958, 1959)]. Textbooks on multivariate analysis were published by Kendall (1957) and Anderson (1958), as well as a monograph by Roy (1957) and a book of tables by Pillai (1957).  相似文献   
143.
This article considers the properties of a nonparametric estimator developed for a reliability function which is used in many reliability problems. Properties such as asymptotic unbiasedness and consistency are proven for the estimator and using U-statistics, weak convergence of the estimator to a normal distribution is shown. Finally, numerical examples based on an extensive simulation study are presented to illustrate the theory and compare the estimator developed in this article with another based directly on the ratio of two empirical distributions studied in Zardasht and Asadi (2010 Zardasht , V. , Asadi , M. ( 2010 ). Evaluation of P(X t  > Y t ) when both X t and Y t are residual lifetimes of two systems . Statistica Neerlandica 64 : 460481 .[Crossref], [Web of Science ®] [Google Scholar]).  相似文献   
144.
We consider Bayesian analysis of threshold autoregressive moving average model with exogenous inputs (TARMAX). In order to obtain the desired marginal posterior distributions of all parameters including the threshold value of the two-regime TARMAX model, we use two different Markov chain Monte Carlo (MCMC) methods to apply Gibbs sampler with Metropolis-Hastings algorithm. The first one is used to obtain iterative least squares estimates of the parameters. The second one includes two MCMC stages for estimate the desired marginal posterior distributions and the parameters. Simulation experiments and a real data example show support to our approaches.  相似文献   
145.
Statistics, as functions of the observations, are usually given by well-behaved functions. This fact is used to obtain limit distributions for statistics whose components are given by asymptotically linear functions. These results are then extended to the moments of distributions, covariance matrices and confidence regions for parameters of interest. These regions may be used to test, through duality, hypothesis on these parameters. A theoretical application is presented.  相似文献   
146.
In this article, we extend the joint frailty models proposed by Zhao and Tong (2011 Zhao , X. , Tong , X. ( 2011 ). Semiparametric regression analysis of panel count data with informative observation times . Comput. Statist. Data. Anal. 55 : 291300 .[Crossref], [Web of Science ®] [Google Scholar]) to panel count data with the time-dependent covariates and informative observation and censoring times. A novel estimating equation approach that does not depend on the distribution of frailty variables and the link function is proposed for estimation of parameters, and the asymptotic properties of the proposed estimators are established. Simulation studies demonstrate that the proposed inference procedure performs well. The analysis of a bladder tumor data is presented to illustrate the method.  相似文献   
147.
An important contribution to the literature on frequentist model averaging (FMA) is the work of Hjort and Claeskens (2003 Hjort , N. L. , Claeskens , G. ( 2003 ). Frequestist model average estimators . J. Amer. Statist. Assoc. 98 : 879899 .[Taylor & Francis Online], [Web of Science ®] [Google Scholar]), who developed an asymptotic theory for frequentist model averaging in parametric models based on a local mis-specification framework. They also proposed a simple method for constructing confidence intervals of the unknown parameters. This article shows that the confidence intervals based on the FMA estimator suggested by Hjort and Claeskens (2003 Hjort , N. L. , Claeskens , G. ( 2003 ). Frequestist model average estimators . J. Amer. Statist. Assoc. 98 : 879899 .[Taylor & Francis Online], [Web of Science ®] [Google Scholar]) are asymptotically equivalent to that obtained from the full model under both parametric and the varying-coefficient partially linear models. Thus, as long as interval estimation rather than point estimation is concerned, the confidence interval based on the full model already fulfills the objective and model averaging provides no additional useful information.  相似文献   
148.
Parameters in the production process of PVC gloves, such as production cycle, oven temperature, temperature, and viscosity of feed liquids are critical to the final quality of gloves. The dosing of feed liquids and plasticization of gloves are all controlled manually, and the viscosities of feed liquids and average oven temperature cannot be exactly regulated; those result in the degradation of final products and unreliability of the process. This article conducted studies on reliability enhancement of glove quality—an integrated control policy based on SPC and EPC was raised to minimize the process fluctuation, stabilize the output quality, and finally improve the process reliability. Using SPC method to eliminate the assignable factors in the process, when the process is under control, the EPC method was applied to make the process parameters closer to the target values which were decided through an inverse model of the process. The theory and methods were verified in the case study of PVC production control.  相似文献   
149.
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   
150.
In this article, we propose the local linear estimators of the drift coefficient and diffusion coefficient in the second-order jump-diffusion model. We also show the consistency and asymptotic normality of these estimators under mild conditions.  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