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941.
Z. Govindarajulu 《Journal of statistical planning and inference》1980,4(3):237-247
Using certain properties of order statistics, the geometric distribution has been characterized when the components are independent and identically distributed. When the components are independent, the geometric distribution has been characterized in the class of either IFR or DFR discrete distributions. In particular, Ferguson's (1967) characterization theorem for independent components in a sample of size two has been extended in several directions. 相似文献
942.
In this paper we consider the statistical analysis of multivariate multiple nonlinear regression models with correlated errors, using Finite Fourier Transforms. Consistency and asymptotic normality of the weighted least squares estimates are established under various conditions on the regressor variables. These conditions involve different types of scalings, and the scaling factors are obtained explicitly for various types of nonlinear regression models including an interesting model which requires the estimation of unknown frequencies. The estimation of frequencies is a classical problem occurring in many areas like signal processing, environmental time series, astronomy and other areas of physical sciences. We illustrate our methodology using two real data sets taken from geophysics and environmental sciences. The data we consider from geophysics are polar motion (which is now widely known as “Chandlers Wobble”), where one has to estimate the drift parameters, the offset parameters and the two periodicities associated with elliptical motion. The data were first analyzed by Arato, Kolmogorov and Sinai who treat it as a bivariate time series satisfying a finite order time series model. They estimate the periodicities using the coefficients of the fitted models. Our analysis shows that the two dominant frequencies are 12 h and 410 days. The second example, we consider is the minimum/maximum monthly temperatures observed at the Antarctic Peninsula (Faraday/Vernadsky station). It is now widely believed that over the past 50 years there is a steady warming in this region, and if this is true, the warming has serious consequences on ecology, marine life, etc. as it can result in melting of ice shelves and glaciers. Our objective here is to estimate any existing temperature trend in the data, and we use the nonlinear regression methodology developed here to achieve that goal. 相似文献
943.
There is a close analogy between empirical distributions of i.i.d. random variables and normalized spectral distributions of wide-sense stationary processes. Herein we make use of this analogy to develop nonparametric comparisons of two spectral distributions and nonparametric tests of stationarity versus change-point alternatives via spectral analysis of a time series. 相似文献
944.
A problem of selecting populations better than a control is considered. When the populations are uniformly distributed, empirical Bayes rules are derived for a linear loss function for both the known control parameter and the unknown control parameter cases. When the priors are assumed to have bounded supports, empirical Bayes rules for selecting good populations are derived for distributions with truncation parameters (i.e. the form of the pdf is f(x|θ)= pi(x)ci(θ)I(0, θ)(x)). Monte Carlo studies are carried out which determine the minimum sample sizes needed to make the relative errors less than ε for given ε-values. 相似文献
945.
Ester Samuel-Cahn 《Journal of statistical planning and inference》1983,8(3):347-354
Let Xi be i.i.d. random variables with finite expectations, and θi arbitrary constants, i=1,…,n. Yi=Xi+θi. The expected range of the Y's is Rn(θ1,…,θn)=E(maxYi-minYi. It is shown that the expected range is minimized if and only if θ1=?=θn. In the case where the Xi are independently and symmetrically distributed around the same constant, but not identically distributed, it is shown that θ1=?=θn are not necessarily the only (θ1,...,θn) minimizing Rn. Some lemmas which are applicable to more general problems of minimizing Rn are also given. 相似文献
946.
We consider the problem of robust M-estimation of a vector of regression parameters, when the errors are dependent. We assume a weakly stationary, but otherwise quite general dependence structure. Our model allows for the representation of the correlations of any time series of finite length. We first construct initial estimates of the regression, scale, and autocorrelation parameters. The initial autocorrelation estimates are used to transform the model to one of approximate independence. In this transformed model, final one-step M-estimates are calculated. Under appropriate assumptions, the regression estimates so obtained are asymptotically normal, with a variance-covariance structure identical to that in the case in which the autocorrelations are known a priori. The results of a simulation study are given. Two versions of our estimator are compared with the L1 -estimator and several Huber-type M-estimators. In terms of bias and mean squared error, the estimators are generally very close. In terms of the coverage probabilities of confidence intervals, our estimators appear to be quite superior to both the L1-estimator and the other estimators. The simulations also indicate that the approach to normality is quite fast. 相似文献
947.
David R. Brillinger 《Revue canadienne de statistique》1994,22(2):177-206
Techniques developed for the study of time series, point processes, and marked point processes can suggest corresponding techniques for each other, and common techniques can be recognized. In this paper connections are drawn based on conceptual foundations, basic parameters, analyses, displays, algorithms, problems, models. The definitions and techniques are brought out by specific scientific problems. The emphasis is on the single-realization stationary case and on the use of second- and third-order moments to help understand the realization. The tool of stacking, at a particular period, is employed in several of the examples. 相似文献
948.
许兰英 《长江大学学报(社会科学版)》1993,(2)
苯甲酸甲基衍生物的气相标准生成焓与取代基的初级效应、次级效应和障碍点有关.本文确立了估算苯甲酸甲基衍生物的气相标准生成焓的新模型.计算值与实验值相吻合,相关系数 r≥0.990. 相似文献
949.
Jose Juan Quesada-Molina 《Statistical Methods and Applications》1992,1(3):405-411
Summary We generalize a well-known identity due to Hoeffding and use this generalization to prove a result of Cambanis, Simons and
Stout under somewhat different hypotheses and to extend some results of Lehmann concerning bivariate distributions with quadrant
dependence. 相似文献
950.
向3G演进的移动通信市场研究 总被引:1,自引:0,他引:1
在对2G到3G演进过程中移动运营商外部环境变化研究的基础上,重点分析了国内移动通信市场的发展趋势,包括3G的竞争格局分析、用户规模分析、业务预测等。 相似文献