全文获取类型
收费全文 | 4229篇 |
免费 | 127篇 |
国内免费 | 15篇 |
专业分类
管理学 | 481篇 |
民族学 | 6篇 |
人口学 | 77篇 |
丛书文集 | 57篇 |
理论方法论 | 107篇 |
综合类 | 370篇 |
社会学 | 262篇 |
统计学 | 3011篇 |
出版年
2024年 | 1篇 |
2023年 | 30篇 |
2022年 | 25篇 |
2021年 | 39篇 |
2020年 | 70篇 |
2019年 | 124篇 |
2018年 | 172篇 |
2017年 | 267篇 |
2016年 | 134篇 |
2015年 | 128篇 |
2014年 | 154篇 |
2013年 | 1023篇 |
2012年 | 305篇 |
2011年 | 161篇 |
2010年 | 138篇 |
2009年 | 176篇 |
2008年 | 170篇 |
2007年 | 159篇 |
2006年 | 125篇 |
2005年 | 139篇 |
2004年 | 118篇 |
2003年 | 99篇 |
2002年 | 78篇 |
2001年 | 79篇 |
2000年 | 73篇 |
1999年 | 64篇 |
1998年 | 55篇 |
1997年 | 41篇 |
1996年 | 22篇 |
1995年 | 17篇 |
1994年 | 27篇 |
1993年 | 18篇 |
1992年 | 21篇 |
1991年 | 17篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1988年 | 14篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
排序方式: 共有4371条查询结果,搜索用时 312 毫秒
101.
《Journal of Statistical Computation and Simulation》2012,82(18):3413-3452
The purpose of this article is to obtain the jackknifed ridge predictors in the linear mixed models and to examine the superiorities, the linear combinations of the jackknifed ridge predictors over the ridge, principal components regression, r?k class and Henderson's predictors in terms of bias, covariance matrix and mean square error criteria. Numerical analyses are considered to illustrate the findings and a simulation study is conducted to see the performance of the jackknifed ridge predictors. 相似文献
102.
This article deals with the estimation of the parametric component, which is of primary interest, in the heteroscedastic semi-varying coefficient models. Based on the bootstrap technique, we present a procedure for estimating the parameters, which can provide a reliable approximation to the asymptotic distribution of the profile least-square (PLS) estimator. Furthermore, a bootstrap-type estimator of covariance matrix is developed, which is proved to be a consistent estimator of the covariance matrix. Moreover, some simulation experiments are conducted to evaluate the finite sample performance for the proposed methodology. Finally, the Australia CPI dataset is analyzed to demonstrate the application of the methods. 相似文献
103.
《Journal of Policy Modeling》2019,41(3):522-536
US trade policy in the Trump administration is protectionist, raising tariffs outside of WTO rules, threatening trade wars, withdrawing from existing trade agreements, and negotiating new bilateral trade deals rather than free trade agreements. The reaction of the rest of the world has been to support the WTO rules-based trading system and to pursue new and expanded regional trade agreements that do not include the US. The result may be US disengagement from the world trading system, with countries diverting trade around the US. We use a global computable general equilibrium (CGE) model to analyze changes in trade and production patterns for a variety of scenarios, including US trade wars. We find that adjustment to US disengagement is feasible—the changes in trade shares as countries divert trade are modest and achievable, with very little impact on the volume of global trade. If the US engages in trade wars with major partners, the best response for other trade partners is to sit out the trade war, accept higher US tariffs, and gain markets from global trade diversion around the US. Finally, because of indirect effects, widespread tariffs fail to benefit the protected sectors—a fallacy of composition in a protectionist trade policy. 相似文献
104.
In modeling disease transmission, contacts are assumed to have different infection rates. A proper simulation must model the heterogeneity in the transmission rates. In this article, we present a computationally efficient algorithm that can be applied to a population with heterogeneous transmission rates. We conducted a simulation study to show that the algorithm is more efficient than other algorithms for sampling the disease transmission in a subset of the heterogeneous population. We use a valid stochastic model of pandemic influenza to illustrate the algorithm and to estimate the overall infection attack rates of influenza A (H1N1) in a Canadian city. 相似文献
105.
Marta Blangiardo 《Journal of applied statistics》2014,41(10):2312-2322
The Eurovision Song Contest is an annual musical competition held among active members of the European Broadcasting Union since 1956. The event is televised live across Europe. Each participating country presents a song and receive a vote based on a combination of tele-voting and jury. Over the years, this has led to speculations of tactical voting, discriminating against some participants and thus inducing bias in the final results. In this paper we investigate the presence of positive or negative bias (which may roughly indicate favouritisms or discrimination) in the votes based on geographical proximity, migration and cultural characteristics of the participating countries through a Bayesian hierarchical model. Our analysis found no evidence of negative bias, although mild positive bias does seem to emerge systematically, linking voters to performers. 相似文献
106.
研究了碎纸片的拼接复原问题,建立了合理有效的碎纸片拼接复原的数学模型;给出了数学软件实现自动拼接的具体算法;结合人工拼接得出复原图片;最后,对所给的拼接方法提出了改进方向. 相似文献
107.
Quasi-likelihood nonlinear models (QLNMs) are an extension of generalized linear model and include a widen class of models as special cases. This article investigates some diagnostic methods in QLNMs. An equivalency between a case-deletion model and a mean-shift outlier model in QLNM is established. Two simulation study and a real dataset are used to illustrate the proposed diagnostic methods. 相似文献
108.
Data sets with excess zeroes are frequently analyzed in many disciplines. A common framework used to analyze such data is the zero-inflated (ZI) regression model. It mixes a degenerate distribution with point mass at zero with a non-degenerate distribution. The estimates from ZI models quantify the effects of covariates on the means of latent random variables, which are often not the quantities of primary interest. Recently, marginal zero-inflated Poisson (MZIP; Long et al. [A marginalized zero-inflated Poisson regression model with overall exposure effects. Stat. Med. 33 (2014), pp. 5151–5165]) and negative binomial (MZINB; Preisser et al., 2016) models have been introduced that model the mean response directly. These models yield covariate effects that have simple interpretations that are, for many applications, more appealing than those available from ZI regression. This paper outlines a general framework for marginal zero-inflated models where the latent distribution is a member of the exponential dispersion family, focusing on common distributions for count data. In particular, our discussion includes the marginal zero-inflated binomial (MZIB) model, which has not been discussed previously. The details of maximum likelihood estimation via the EM algorithm are presented and the properties of the estimators as well as Wald and likelihood ratio-based inference are examined via simulation. Two examples presented illustrate the advantages of MZIP, MZINB, and MZIB models for practical data analysis. 相似文献
109.
In this paper, we propose a model based on multivariate decomposition of multiplicative – absolute values and signs – components of asset returns. In the m-variate case, the marginals for the m absolute values and the binary marginals for the m directions are linked through a 2m-dimensional copula. The approach is detailed in the case of a bivariate decomposition. We outline the construction of the likelihood function and the computation of different conditional measures. The finite-sample properties of the maximum likelihood estimator are assessed by simulation. An application to predicting bond returns illustrates the usefulness of the proposed method. 相似文献
110.
In this article, to reduce computational load in performing Bayesian variable selection, we used a variant of reversible jump Markov chain Monte Carlo methods, and the Holmes and Held (HH) algorithm, to sample model index variables in logistic mixed models involving a large number of explanatory variables. Furthermore, we proposed a simple proposal distribution for model index variables, and used a simulation study and real example to compare the performance of the HH algorithm with our proposed and existing proposal distributions. The results show that the HH algorithm with our proposed proposal distribution is a computationally efficient and reliable selection method. 相似文献