全文获取类型
收费全文 | 678篇 |
免费 | 30篇 |
国内免费 | 4篇 |
专业分类
管理学 | 64篇 |
民族学 | 3篇 |
人口学 | 64篇 |
丛书文集 | 14篇 |
理论方法论 | 84篇 |
综合类 | 65篇 |
社会学 | 296篇 |
统计学 | 122篇 |
出版年
2024年 | 2篇 |
2023年 | 5篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 20篇 |
2019年 | 27篇 |
2018年 | 43篇 |
2017年 | 50篇 |
2016年 | 33篇 |
2015年 | 18篇 |
2014年 | 22篇 |
2013年 | 121篇 |
2012年 | 26篇 |
2011年 | 32篇 |
2010年 | 41篇 |
2009年 | 25篇 |
2008年 | 31篇 |
2007年 | 18篇 |
2006年 | 27篇 |
2005年 | 29篇 |
2004年 | 14篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有712条查询结果,搜索用时 0 毫秒
711.
Consider the problem of discriminating between the polynomial regression models on [?1, 1] and estimating parameters in the models. Zen and Tsai (2002) proposed a multiple-objective optimality criterion, M γ-criterion, which uses weight γ (0 ≤ γ ≤ 1) for model discrimination and α = β = (1 ? γ)/2 for parameter estimation in each model. In this article, we generalize it to a wider setup with different values of α and β. For instance, α = 2 β suggests that the “smaller” model is more likely to be the true model. Using similar techniques, the corresponding criterion-robust optimal design is investigated. A study for the original criterion-robust optimal design with α = β, through M-efficiency, shows that it is good enough for any wider setup. 相似文献
712.
This article considers a discrete-time Markov chain for modeling transition probabilities when multiple successive observations are missing at random between two observed outcomes using three methods: a na\"?ve analog of complete-case analysis using the observed one-step transitions alone, a non data-augmentation method (NL) by solving nonlinear equations, and a data-augmentation method, the Expectation-Maximization (EM) algorithm. The explicit form of the conditional log-likelihood given the observed information as required by the E step is provided, and the iterative formula in the M step is expressed in a closed form. An empirical study was performed to examine the accuracy and precision of the estimates obtained in the three methods under ignorable missing mechanisms of missing completely at random and missing at random. A dataset from the mental health arena was used for illustration. It was found that both data-augmentation and nonaugmentation methods provide accurate and precise point estimation, and that the na\"?ve method resulted in estimates of the transition probabilities with similar bias but larger MSE. The NL method and the EM algorithm in general provide similar results whereas the latter provides conditional expected row margins leading to smaller standard errors. 相似文献