全文获取类型
收费全文 | 8425篇 |
免费 | 161篇 |
国内免费 | 38篇 |
专业分类
管理学 | 388篇 |
民族学 | 28篇 |
人口学 | 150篇 |
丛书文集 | 269篇 |
理论方法论 | 126篇 |
综合类 | 2045篇 |
社会学 | 83篇 |
统计学 | 5535篇 |
出版年
2024年 | 6篇 |
2023年 | 30篇 |
2022年 | 65篇 |
2021年 | 66篇 |
2020年 | 125篇 |
2019年 | 235篇 |
2018年 | 266篇 |
2017年 | 515篇 |
2016年 | 179篇 |
2015年 | 196篇 |
2014年 | 285篇 |
2013年 | 2357篇 |
2012年 | 634篇 |
2011年 | 334篇 |
2010年 | 261篇 |
2009年 | 279篇 |
2008年 | 300篇 |
2007年 | 292篇 |
2006年 | 245篇 |
2005年 | 285篇 |
2004年 | 223篇 |
2003年 | 211篇 |
2002年 | 204篇 |
2001年 | 190篇 |
2000年 | 164篇 |
1999年 | 98篇 |
1998年 | 80篇 |
1997年 | 66篇 |
1996年 | 50篇 |
1995年 | 39篇 |
1994年 | 35篇 |
1993年 | 41篇 |
1992年 | 34篇 |
1991年 | 31篇 |
1990年 | 29篇 |
1989年 | 27篇 |
1988年 | 18篇 |
1987年 | 20篇 |
1986年 | 10篇 |
1985年 | 14篇 |
1984年 | 18篇 |
1983年 | 20篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 5篇 |
排序方式: 共有8624条查询结果,搜索用时 648 毫秒
141.
《Journal of Statistical Computation and Simulation》2012,82(2):293-305
Folded normal distribution originates from the modulus of normal distribution. In the present article, we have formulated the cumulative distribution function (cdf) of a folded normal distribution in terms of standard normal cdf and the parameters of the mother normal distribution. Although cdf values of folded normal distribution were earlier tabulated in the literature, we have shown that those values are valid for very particular situations. We have also provided a simple approach to obtain values of the parameters of the mother normal distribution from those of the folded normal distribution. These results find ample application in practice, for example, in obtaining the so-called upper and lower α-points of folded normal distribution, which, in turn, is useful in testing of the hypothesis relating to folded normal distribution and in designing process capability control chart of some process capability indices. A thorough study has been made to compare the performance of the newly developed theory to the existing ones. Some simulated as well as real-life examples have been discussed to supplement the theory developed in this article. Codes (generated by R software) for the theory developed in this article are also presented for the ease of application. 相似文献
142.
《Journal of Statistical Computation and Simulation》2012,82(12):1317-1333
We propose autoregressive moving average (ARMA) and generalized autoregressive conditional heteroscedastic (GARCH) models driven by asymmetric Laplace (AL) noise. The AL distribution plays, in the geometric-stable class, the analogous role played by the normal in the alpha-stable class, and has shown promise in the modelling of certain types of financial and engineering data. In the case of an ARMA model we derive the marginal distribution of the process, as well as its bivariate distribution when separated by a finite number of lags. The calculation of exact confidence bands for minimum mean-squared error linear predictors is shown to be straightforward. Conditional maximum likelihood-based inference is advocated, and corresponding asymptotic results are discussed. The models are particularly suited for processes that are skewed, peaked, and leptokurtic, but which appear to have some higher order moments. A case study of a fund of real estate returns reveals that AL noise models tend to deliver a superior fit with substantially less parameters than normal noise counterparts, and provide both a competitive fit and a greater degree of numerical stability with respect to other skewed distributions. 相似文献
143.
《Journal of Statistical Computation and Simulation》2012,82(7):951-979
For any continuous baseline G distribution [G.M. Cordeiro and M. de Castro, A new family of generalized distributions, J. Statist. Comput. Simul. 81 (2011), pp. 883–898], proposed a new generalized distribution (denoted here with the prefix ‘Kw-G’ (Kumaraswamy-G)) with two extra positive parameters. They studied some of its mathematical properties and presented special sub-models. We derive a simple representation for the Kw-G density function as a linear combination of exponentiated-G distributions. Some new distributions are proposed as sub-models of this family, for example, the Kw-Chen [Z.A. Chen, A new two-parameter lifetime distribution with bathtub shape or increasing failure rate function, Statist. Probab. Lett. 49 (2000), pp. 155–161], Kw-XTG [M. Xie, Y. Tang, and T.N. Goh, A modified Weibull extension with bathtub failure rate function, Reliab. Eng. System Safety 76 (2002), pp. 279–285] and Kw-Flexible Weibull [M. Bebbington, C.D. Lai, and R. Zitikis, A flexible Weibull extension, Reliab. Eng. System Safety 92 (2007), pp. 719–726]. New properties of the Kw-G distribution are derived which include asymptotes, shapes, moments, moment generating function, mean deviations, Bonferroni and Lorenz curves, reliability, Rényi entropy and Shannon entropy. New properties of the order statistics are investigated. We discuss the estimation of the parameters by maximum likelihood. We provide two applications to real data sets and discuss a bivariate extension of the Kw-G distribution. 相似文献
144.
B. Lagos Álvarez 《Journal of statistical planning and inference》2012,142(2):608-612
The skew t distribution is a flexible parametric family to fit data, because it includes parameters that let us regulate skewness and kurtosis. A problem with this distribution is that, for moderate sample sizes, the maximum likelihood estimator of the shape parameter is infinite with positive probability. In order to try to solve this problem, Sartori (2006) has proposed using a modified score function as an estimating equation for the shape parameter. In this note we prove that the resulting modified maximum likelihood estimator is always finite, considering the degrees of freedom as known and greater than or equal to 2. 相似文献
145.
《Journal of Statistical Computation and Simulation》2012,82(7):775-791
In this work, we discuss the class of bilinear GARCH (BL-GARCH) models that are capable of capturing simultaneously two key properties of non-linear time series: volatility clustering and leverage effects. It has often been observed that the marginal distributions of such time series have heavy tails; thus we examine the BL-GARCH model in a general setting under some non-normal distributions. We investigate some probabilistic properties of this model and we conduct a Monte Carlo experiment to evaluate the small-sample performance of the maximum likelihood estimation (MLE) methodology for various models. Finally, within-sample estimation properties were studied using S&P 500 daily returns, when the features of interest manifest as volatility clustering and leverage effects. The main results suggest that the Student-t BL-GARCH seems highly appropriate to describe the S&P 500 daily returns. 相似文献
146.
Bayesian acceptance sampling plans, which utilize prior information on the process variation, can be employed as an alternative to conventional types of plans for taking decisions on the disposition of submitted lots. A special type of double sampling inspection plans by attributes with small acceptance numbers using Bayesian methodology is presented in this paper emphasizing its significance over small acceptance number single sampling plans. The procedures for designing such sampling plans for specified degree of discrimination which would ensure protection to the producer and consumer are discussed with illustrations under the conditions for the application of gamma-Poisson distribution. 相似文献
147.
《Journal of Statistical Computation and Simulation》2012,82(1-2):65-78
This paper examines the least squares estimator of the autoregressive coefficient in a first-order sta¬tionary autoregressive model. Exact lower-order moments are computed by numerical integrations. From the study of moment values, it is found that the exact distribution of the least squares estimator may be well approximated by a beta distribution. 相似文献
148.
《Journal of Statistical Computation and Simulation》2012,82(2-3):133-143
Goodness—of—fit statistics based on the empirical distribution function (EDF) are not distribution—free when parameters for the hypothesized distribution are estimated. Tables are percentile values of several EDF statistics are available for the two—parameter Weibull distribution when parameters are estimated by maximum likelihood. To determine how these tabled values change when simpler estimators are employed, percentile scores for EDF goodness—of—fit tests were obtained by Monte—Carlo simulation for maximum likelihood estimators (MLEs), good linear unbiased estimators (GLUEs), and modified Cramer—von Mises, Anderson—Darling, and Watson statistics are presented for GLUEs for both complete and censored samples. Critical values for Kolmogorov—Smirnov statistics were less affected by the method of estimation than were closer for MLEs and MGLUEs than for MGLUEs and GLUEs. On the other hand, MGLUE and GLUE results were much more similar to each other than to the MLE results when censoring was light and sample sizes were large. 相似文献
149.
Parisa Zarrin Zahra Khodadai Reinaldo B. Arellano-Valle 《Journal of Statistical Computation and Simulation》2019,89(1):38-51
The standard location and scale unrestricted (or unified) skew-normal (SUN) family studied by Arellano-Valle and Genton [On fundamental skew distributions. J Multivar Anal. 2005;96:93–116] and Arellano-Valle and Azzalini [On the unification of families of skew-normal distributions. Scand J Stat. 2006;33:561–574], allows the modelling of data which is symmetrically or asymmetrically distributed. The family has a number of advantages suitable for the analysis of stochastic processes such as Auto-Regressive Moving-Average (ARMA) models, including being closed under linear combinations, being able to satisfy the consistency condition of Kolmogorov’s theorem and providing the guarantee of the existence of such a SUN stochastic process. The family is able to be represented in a hierarchical form which can be used for the ease of simulation. In addition, it facilitates an EM-type algorithm to estimate the model parameters. The performances and suitability of the proposed model are demonstrated on simulations and using two real data sets in applications. 相似文献
150.
《Journal of Statistical Computation and Simulation》2012,82(3-4):245-254
A simulation study was carried out to compare the performances of two different simple estimators of the location parameter for a three-parameter Weibull distribution Both Estimators have been suggested by recent paper in the literature. Bras and mean square error are examined for many different sample-size and shape-parameter-value combinations. Strong evidence of the domination of one estimator over the other is found. 相似文献