全文获取类型
收费全文 | 3485篇 |
免费 | 68篇 |
国内免费 | 17篇 |
专业分类
管理学 | 164篇 |
劳动科学 | 1篇 |
民族学 | 6篇 |
人才学 | 1篇 |
人口学 | 31篇 |
丛书文集 | 103篇 |
理论方法论 | 28篇 |
综合类 | 951篇 |
社会学 | 35篇 |
统计学 | 2250篇 |
出版年
2024年 | 1篇 |
2023年 | 13篇 |
2022年 | 16篇 |
2021年 | 22篇 |
2020年 | 60篇 |
2019年 | 89篇 |
2018年 | 109篇 |
2017年 | 173篇 |
2016年 | 68篇 |
2015年 | 78篇 |
2014年 | 134篇 |
2013年 | 911篇 |
2012年 | 272篇 |
2011年 | 124篇 |
2010年 | 144篇 |
2009年 | 100篇 |
2008年 | 115篇 |
2007年 | 125篇 |
2006年 | 129篇 |
2005年 | 107篇 |
2004年 | 104篇 |
2003年 | 83篇 |
2002年 | 68篇 |
2001年 | 81篇 |
2000年 | 80篇 |
1999年 | 45篇 |
1998年 | 49篇 |
1997年 | 39篇 |
1996年 | 44篇 |
1995年 | 36篇 |
1994年 | 14篇 |
1993年 | 21篇 |
1992年 | 20篇 |
1991年 | 9篇 |
1990年 | 13篇 |
1989年 | 13篇 |
1988年 | 12篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有3570条查询结果,搜索用时 15 毫秒
1.
Rodolphe Priam 《统计学通讯:理论与方法》2020,49(18):4468-4489
AbstractThe mean estimators with ratio depend on multiple auxiliary variables and unknown parameters in a finite population setting. We propose a new generalized approach with matrices for modeling the mutivariate mean estimators with two auxiliary variables. Our approach brings naturally a graphical analysis for comparing mean estimators. 相似文献
2.
On Optimality of Bayesian Wavelet Estimators 总被引:2,自引:0,他引:2
Felix Abramovich Umberto Amato Claudia Angelini 《Scandinavian Journal of Statistics》2004,31(2):217-234
Abstract. We investigate the asymptotic optimality of several Bayesian wavelet estimators, namely, posterior mean, posterior median and Bayes Factor, where the prior imposed on wavelet coefficients is a mixture of a mass function at zero and a Gaussian density. We show that in terms of the mean squared error, for the properly chosen hyperparameters of the prior, all the three resulting Bayesian wavelet estimators achieve optimal minimax rates within any prescribed Besov space for p ≥ 2. For 1 ≤ p < 2, the Bayes Factor is still optimal for (2 s +2)/(2 s +1) ≤ p < 2 and always outperforms the posterior mean and the posterior median that can achieve only the best possible rates for linear estimators in this case. 相似文献
3.
John D. Emerson David C. Hoaglin Frederick Mosteller 《Statistical Methods and Applications》1993,2(3):269-290
Summary Meta-analyses of sets of clinical trials often combine risk differences from several 2×2 tables according to a random-effects
model. The DerSimonian-Laird random-effects procedure, widely used for estimating the populaton mean risk difference, weights
the risk difference from each primary study inversely proportional to an estimate of its variance (the sum of the between-study
variance and the conditional within-study variance). Because those weights are not independent of the risk differences, however,
the procedure sometimes exhibits bias and unnatural behavior. The present paper proposes a modified weighting scheme that
uses the unconditional within-study variance to avoid this source of bias. The modified procedure has variance closer to that
available from weighting by ideal weights when such weights are known. We studied the modified procedure in extensive simulation
experiments using situations whose parameters resemble those of actual studies in medical research. For comparison we also
included two unbiased procedures, the unweighted mean and a sample-size-weighted mean; their relative variability depends
on the extent of heterogeneity among the primary studies. An example illustrates the application of the procedures to actual
data and the differences among the results.
This research was supported by Grant HS 05936 from the Agency for Health Care Policy and Research to Harvard University. 相似文献
4.
5.
Angelo Zanella 《Statistical Methods and Applications》1992,1(1):143-160
Summary For technological applications it can be useful to identify some simple physical mechanisms, which, on the basis of the available
knowledge of the production process, may suggest the most appropriate approach to statistical control of the random quantities
of interest. For this purpose the notion of rupture point is introduced firstly. A rupture point is characterized bym randomly arising out of control states, assumed to be mutually exclusive and stochastically independent. Shewhart's control
charts seem to represent the natural statistical tool for controlling a rupture point; however it is shown that they are fully
justified only when the hazard rates attached to the causes of failure are constant. Otherwise, typically in the presence
of time increasing hazard rates, Shewhart's control charts should be completed by a preventive intervention rule (preventive
maintenance). In the second place, the notion of dynamic instability point is introduced, which is specifically characterized
by assuming that the random quantity of interest is ruled by a stochastic differential equation with constant coefficients.
By discretization, developed according to a possibly new approach, it is shown that the former model reduces to an equation
error model, which is among the simplest used in adaptive control, and thus particularly easy to deal with in regard to parameter
estimation and the definition of the optimum control rule. 相似文献
6.
Longitudinal data often contain missing observations, and it is in general difficult to justify particular missing data mechanisms, whether random or not, that may be hard to distinguish. The authors describe a likelihood‐based approach to estimating both the mean response and association parameters for longitudinal binary data with drop‐outs. They specify marginal and dependence structures as regression models which link the responses to the covariates. They illustrate their approach using a data set from the Waterloo Smoking Prevention Project They also report the results of simulation studies carried out to assess the performance of their technique under various circumstances. 相似文献
7.
中国交通运输业发展的实证研究 总被引:1,自引:0,他引:1
采用协整和误差纠正模型与方法,对中国改革开放20多年来交通运输发展与一些相关影响因素之间的关系进行实证研究。结果表明:旅客运输需求与国民收入、乘车费用之间,货物运输与国民经济、燃油价格之间分别存在长期稳定关系。研究认为:中国交通的发展应适当超前于国民经济的发展。同时,研究还发现:“旅游黄金周”的实施并不是促进中国旅客运输需求的显著影响因素。 相似文献
8.
WEIGHTED SUMS OF NEGATIVELY ASSOCIATED RANDOM VARIABLES 总被引:2,自引:0,他引:2
In this paper, we establish strong laws for weighted sums of negatively associated (NA) random variables which have a higher‐order moment condition. Some results of Bai Z.D. & Cheng P.E. (2000) [Marcinkiewicz strong laws for linear statistics. Statist. and Probab. Lett. 43, 105–112,] and Sung S.K. (2001) [Strong laws for weighted sums of i.i.d. random variables, Statist. and Probab. Lett. 52, 413–419] are sharpened and extended from the independent identically distributed case to the NA setting. Also, one of the results of Li D.L. et al. (1995) [Complete convergence and almost sure convergence of weighted sums of random variables. J. Theoret. Probab. 8, 49–76,] is complemented and extended. 相似文献
9.
Annual concentrations of toxic air contaminants are of primary concern from the perspective of chronic human exposure assessment and risk analysis. Despite recent advances in air quality monitoring technology, resource and technical constraints often impose limitations on the availability of a sufficient number of ambient concentration measurements for performing environmental risk analysis. Therefore, sample size limitations, representativeness of data, and uncertainties in the estimated annual mean concentration must be examined before performing quantitative risk analysis. In this paper, we discuss several factors that need to be considered in designing field-sampling programs for toxic air contaminants and in verifying compliance with environmental regulations. Specifically, we examine the behavior of SO2, TSP, and CO data as surrogates for toxic air contaminants and as examples of point source, area source, and line source-dominated pollutants, respectively, from the standpoint of sampling design. We demonstrate the use of bootstrap resampling method and normal theory in estimating the annual mean concentration and its 95% confidence bounds from limited sampling data, and illustrate the application of operating characteristic (OC) curves to determine optimum sample size and other sampling strategies. We also outline a statistical procedure, based on a one-sided t-test, that utilizes the sampled concentration data for evaluating whether a sampling site is compliance with relevant ambient guideline concentrations for toxic air contaminants. 相似文献
10.
Mark Bebbington Chin-Diew Lai Riardas Zitikis 《Australian & New Zealand Journal of Statistics》2007,49(3):251-265
Finding optimal, or at least good, maintenance and repair policies is crucial in reliability engineering. Likewise, describing life phases of human mortality is important when determining social policy or insurance premiums. In these tasks, one searches for distributions to fit data and then makes inferences about the population(s). In the present paper, we focus on bathtub‐type distributions and provide a view of certain problems, methods and solutions, and a few challenges, that can be encountered in reliability engineering, survival analysis, demography and actuarial science. 相似文献