全文获取类型
收费全文 | 452篇 |
免费 | 16篇 |
专业分类
管理学 | 92篇 |
民族学 | 2篇 |
人口学 | 26篇 |
丛书文集 | 1篇 |
理论方法论 | 58篇 |
综合类 | 20篇 |
社会学 | 177篇 |
统计学 | 92篇 |
出版年
2023年 | 7篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 16篇 |
2017年 | 18篇 |
2016年 | 10篇 |
2015年 | 18篇 |
2014年 | 11篇 |
2013年 | 66篇 |
2012年 | 17篇 |
2011年 | 18篇 |
2010年 | 18篇 |
2009年 | 23篇 |
2008年 | 21篇 |
2007年 | 18篇 |
2006年 | 13篇 |
2005年 | 14篇 |
2004年 | 17篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 17篇 |
1999年 | 7篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1984年 | 5篇 |
1981年 | 3篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1963年 | 2篇 |
1962年 | 2篇 |
排序方式: 共有468条查询结果,搜索用时 15 毫秒
101.
This paper considers the maximin approach for designing clinical studies. A maximin efficient design maximizes the smallest efficiency when compared with a standard design, as the parameters vary in a specified subset of the parameter space. To specify this subset of parameters in a real situation, a four‐step procedure using elicitation based on expert opinions is proposed. Further, we describe why and how we extend the initially chosen subset of parameters to a much larger set in our procedure. By this procedure, the maximin approach becomes feasible for dose‐finding studies. Maximin efficient designs have shown to be numerically difficult to construct. However, a new algorithm, the H‐algorithm, considerably simplifies the construction of these designs. We exemplify the maximin efficient approach by considering a sigmoid Emax model describing a dose–response relationship and compare inferential precision with that obtained when using a uniform design. The design obtained is shown to be at least 15% more efficient than the uniform design. © 2014 The Authors. Pharmaceutical Statistics Published by John Wiley & Sons Ltd. 相似文献
102.
103.
Hans G. Krijnen 《Long Range Planning》1979,12(2):63-75
In this article an attempt is made at giving a more concrete meaning to the notion of flexibility of a firm. The relationship between the dynamics of the environment on the one hand and the chosen strategy and organizational structure of the firm on the other, will be further analysed The aiming at flexibility is considered to be a separate economic basic goal next to rentability and independence, as firms increasingly happen to be in a turbulent environment. Special attention is given to the flexibility of a number of different organizational structures.It appears that a number of global recommendations can be made concerning the choice of strategy and organizational structure while explicitly taking the flexibility goal into account. 相似文献
104.
In this paper we introduce a sequential seasonal unit root testing approach which explicitly addresses its application to high frequency data. The main idea is to see which unit roots at higher frequency data can also be found in temporally aggregated data. We illustrate our procedure to the analysis of monthly data, and we find, upon analysing the aggregated quarterly data, that a smaller amount of test statistics can sometimes be considered. Monte Carlo simulation and empirical illustrations emphasize the practical relevance of our method. 相似文献
105.
We provide a simple justification as to why the core principal in liberal democracies the one-person-one-vote is desirable. We compare two possible constitutions. In a fixed democracy, each individual has one vote and the same opportunity to propose public projects. In a flexible democracy, those that set the agenda can additionally propose to limit future participation in voting and agenda-setting. We show that a fixed democracy restricts majorities from taxing minorities to a greater extent than a flexible democracy. A flexible democracy may be more suited to enable a polity to undertake public projects. This possible advantage may be too small to outweigh taxation distortions and citizens unanimously favor the one-person-one-vote rule ex ante.I am grateful to Ami Glazer, Ulrich Erlenmaier, Tobias Kleinschmidt, seminar participants in Heidelberg and Konstanz, and in particular to an anonymous referee for valuable suggestions and comments. 相似文献
106.
This paper is concerned with the existence of temporary equilibria of migration with an overlapping generation structure and analyzes some of its properties. In the first part of the paper sufficient conditions for the existence of a temporary equilibrium of migration (in a given period) are given. In the second part some interesting properties of migration equilibria are analyzed. In particular the effects of differing degrees of information of the individuals on migration equilibria are investigated. Furthermore, it is shown that incomplete information alone suffices to induce migration flows even between countries that can be regarded as identical from an economic point of view.The paper was partly written during a research stay at the Sonderforschungsbereich 178 (University of Konstanz). Financial support of the Deutsche Forschungsgemeinschaft is gratefully acknowledged. We wish to thank an anonymous referee for helpful comments. 相似文献
107.
Laypeople''s and Experts'' Perception of Nanotechnology Hazards 总被引:1,自引:0,他引:1
Michael Siegrist Carmen Keller Hans Kastenholz Silvia Frey Arnim Wiek 《Risk analysis》2007,27(1):59-69
Public perception of nanotechnology may influence the realization of technological advances. Laypeople's (N=375) and experts' (N=46) perception of 20 different nanotechnology applications and three nonnanotechnology applications were examined. The psychometric paradigm was utilized and applications were described in short scenarios. Results showed that laypeople and experts assessed asbestos as much more risky than nanotechnology applications. Analyses of aggregated data suggested that perceived dreadfulness of applications and trust in governmental agencies are important factors in determining perceived risks. Similar results were observed for experts and laypeople, but the latter perceived greater risks than the former. Analyses of individual data showed that trust, perceived benefits, and general attitudes toward technology influenced the perceived risk of laypeople. In the expert sample, confidence in governmental agencies was an important predictor of risks associated with nanotechnology applications. Results suggest that public concerns about nanotechnology would diminish if measures were taken to enhance laypeople's trust in governmental agencies. 相似文献
108.
In oncology/hematology early phase clinical trials, efficacies were often observed in terms of response rate, depth, timing, and duration. However, the true clinical benefits that eventually support registrational purpose are progression-free survival (PFS) and/or overall survival (OS), the follow-up of which are typically not long enough in early phase trials. This gap imposes challenges in strategies for late phase drug development. In this article, we tackle the question by leveraging published study to establish a quantitative link between early efficacy outcomes and late phase efficacy endpoints. We used solid tumor cancer as disease model. We modeled the disease course of a RECISTv1.1 assessed solid tumor with a continuous Markov chain (CMC) model. We parameterize the transition intensity matrix of a CMC model based on published aggregate-level summary statistics, and then simulate subject-level time-to-event data. The simulated data is shown to have good approximation to published studies. PFS and/or OS could be predicted with the transition intensity matrix modified given clinical knowledge to reflect various assumptions on response rate, depth, timing, and duration. The authors have built a R shiny application named PubPredict, the tool implements the algorithm described above and allows customized features including multiple response levels, treatment crossover and varying follow-up duration. This toolset has been applied to advise phase 3 trial design when only early efficacy data are available from phase 1 or 2 studies. 相似文献
109.
Kaspar Rufibach Lynda Grinsted Jiang Li Hans Jochen Weber Cheng Zheng Jiangxiu Zhou 《Pharmaceutical statistics》2023,22(4):671-691
For the analysis of a time-to-event endpoint in a single-arm or randomized clinical trial it is generally perceived that interpretation of a given estimate of the survival function, or the comparison between two groups, hinges on some quantification of the amount of follow-up. Typically, a median of some loosely defined quantity is reported. However, whatever median is reported, is typically not answering the question(s) trialists actually have in terms of follow-up quantification. In this paper, inspired by the estimand framework, we formulate a comprehensive list of relevant scientific questions that trialists have when reporting time-to-event data. We illustrate how these questions should be answered, and that reference to an unclearly defined follow-up quantity is not needed at all. In drug development, key decisions are made based on randomized controlled trials, and we therefore also discuss relevant scientific questions not only when looking at a time-to-event endpoint in one group, but also for comparisons. We find that different thinking about some of the relevant scientific questions around follow-up is required depending on whether a proportional hazards assumption can be made or other patterns of survival functions are anticipated, for example, delayed separation, crossing survival functions, or the potential for cure. We conclude the paper with practical recommendations. 相似文献
110.
Van Eetvelde Hans Hvattum Lars Magnus Ley Christophe 《AStA Advances in Statistical Analysis》2023,107(1-2):251-269
AStA Advances in Statistical Analysis - The COVID-19 pandemic has left its marks in the sports world, forcing the full stop of all sports-related activities in the first half of 2020. Football... 相似文献