全文获取类型
收费全文 | 2022篇 |
免费 | 64篇 |
国内免费 | 7篇 |
专业分类
管理学 | 149篇 |
民族学 | 3篇 |
人才学 | 1篇 |
人口学 | 34篇 |
丛书文集 | 55篇 |
理论方法论 | 79篇 |
综合类 | 410篇 |
社会学 | 216篇 |
统计学 | 1146篇 |
出版年
2024年 | 1篇 |
2023年 | 25篇 |
2022年 | 10篇 |
2021年 | 14篇 |
2020年 | 61篇 |
2019年 | 85篇 |
2018年 | 85篇 |
2017年 | 104篇 |
2016年 | 64篇 |
2015年 | 44篇 |
2014年 | 71篇 |
2013年 | 513篇 |
2012年 | 164篇 |
2011年 | 75篇 |
2010年 | 61篇 |
2009年 | 75篇 |
2008年 | 78篇 |
2007年 | 78篇 |
2006年 | 69篇 |
2005年 | 71篇 |
2004年 | 57篇 |
2003年 | 51篇 |
2002年 | 53篇 |
2001年 | 34篇 |
2000年 | 20篇 |
1999年 | 20篇 |
1998年 | 21篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有2093条查询结果,搜索用时 125 毫秒
1.
Dennis Wagenaar Tiaravanni Hermawan Marc J. C. van den Homberg Jeroen C. J. H. Aerts Heidi Kreibich Hans de Moel Laurens M. Bouwer 《Risk analysis》2021,41(1):37-55
Damage models for natural hazards are used for decision making on reducing and transferring risk. The damage estimates from these models depend on many variables and their complex sometimes nonlinear relationships with the damage. In recent years, data‐driven modeling techniques have been used to capture those relationships. The available data to build such models are often limited. Therefore, in practice it is usually necessary to transfer models to a different context. In this article, we show that this implies the samples used to build the model are often not fully representative for the situation where they need to be applied on, which leads to a “sample selection bias.” In this article, we enhance data‐driven damage models by applying methods, not previously applied to damage modeling, to correct for this bias before the machine learning (ML) models are trained. We demonstrate this with case studies on flooding in Europe, and typhoon wind damage in the Philippines. Two sample selection bias correction methods from the ML literature are applied and one of these methods is also adjusted to our problem. These three methods are combined with stochastic generation of synthetic damage data. We demonstrate that for both case studies, the sample selection bias correction techniques reduce model errors, especially for the mean bias error this reduction can be larger than 30%. The novel combination with stochastic data generation seems to enhance these techniques. This shows that sample selection bias correction methods are beneficial for damage model transfer. 相似文献
2.
When a candidate predictive marker is available, but evidence on its predictive ability is not sufficiently reliable, all‐comers trials with marker stratification are frequently conducted. We propose a framework for planning and evaluating prospective testing strategies in confirmatory, phase III marker‐stratified clinical trials based on a natural assumption on heterogeneity of treatment effects across marker‐defined subpopulations, where weak rather than strong control is permitted for multiple population tests. For phase III marker‐stratified trials, it is expected that treatment efficacy is established in a particular patient population, possibly in a marker‐defined subpopulation, and that the marker accuracy is assessed when the marker is used to restrict the indication or labelling of the treatment to a marker‐based subpopulation, ie, assessment of the clinical validity of the marker. In this paper, we develop statistical testing strategies based on criteria that are explicitly designated to the marker assessment, including those examining treatment effects in marker‐negative patients. As existing and developed statistical testing strategies can assert treatment efficacy for either the overall patient population or the marker‐positive subpopulation, we also develop criteria for evaluating the operating characteristics of the statistical testing strategies based on the probabilities of asserting treatment efficacy across marker subpopulations. Numerical evaluations to compare the statistical testing strategies based on the developed criteria are provided. 相似文献
3.
This study investigates how individuals assess imprecise information. We focus on two essential dimensions of decision under uncertainty, outcomes and probabilities, and their respective precision. We believe the precision of information is highly relevant in the investment setting, as reflected in the well-known “home (familiarity) bias”, and the outcome and probability dimensions, separately or jointly, may affect investors’ knowledge of uncertainty and perceived risk of the investment options, and subsequently affect investors’ choices. To test this conjecture, we conducted three experiments. Our results show that 1) participants demonstrate a pattern of preference for precision and aversion of extreme vagueness and associate vagueness with higher perceived risk and lower investment (experiments one and two); 2) participants prefer vague outcome information to vague probability information (experiment two); 3) familiarity indeed positively affects the precision of estimated values, but this association is stronger for the outcome dimension than for probabilities (experiment three). Our results confirm that precision in information, especially in the outcome dimension has an impact on investors’ resource allocation choices. 相似文献
4.
5.
A. M. Abd El-Raheem 《Journal of Statistical Computation and Simulation》2019,89(16):3075-3104
The generalized half-normal (GHN) distribution and progressive type-II censoring are considered in this article for studying some statistical inferences of constant-stress accelerated life testing. The EM algorithm is considered to calculate the maximum likelihood estimates. Fisher information matrix is formed depending on the missing information law and it is utilized for structuring the asymptomatic confidence intervals. Further, interval estimation is discussed through bootstrap intervals. The Tierney and Kadane method, importance sampling procedure and Metropolis-Hastings algorithm are utilized to compute Bayesian estimates. Furthermore, predictive estimates for censored data and the related prediction intervals are obtained. We consider three optimality criteria to find out the optimal stress level. A real data set is used to illustrate the importance of GHN distribution as an alternative lifetime model for well-known distributions. Finally, a simulation study is provided with discussion. 相似文献
6.
Generally, the semiclosed-form option pricing formula for complex financial models depends on unobservable factors such as stochastic volatility and jump intensity. A popular practice is to use an estimate of these latent factors to compute the option price. However, in many situations this plug-and-play approximation does not yield the appropriate price. This article examines this bias and quantifies its impacts. We decompose the bias into terms that are related to the bias on the unobservable factors and to the precision of their point estimators. The approximated price is found to be highly biased when only the history of the stock price is used to recover the latent states. This bias is corrected when option prices are added to the sample used to recover the states' best estimate. We also show numerically that such a bias is propagated on calibrated parameters, leading to erroneous values. The Canadian Journal of Statistics 48: 8–35; 2020 © 2019 Statistical Society of Canada 相似文献
7.
Arnfinn H. Midtbøen 《The British journal of sociology》2015,66(1):193-214
Although field experiments have documented the contemporary relevance of discrimination in employment, theories developed to explain the dynamics of differential treatment cannot account for differences across organizational and institutional contexts. In this article, I address this shortcoming by presenting the main empirical findings from a multi‐method research project, in which a field experiment of ethnic discrimination in the Norwegian labour market was complemented with forty‐two in‐depth interviews with employers who were observed in the first stage of the study. While the experimental data support earlier findings in documenting that ethnic discrimination indeed takes place, the qualitative material suggests that theorizing in the field experiment literature have been too concerned with individual and intra‐psychic explanations. Discriminatory outcomes in employment processes seems to be more dependent on contextual factors such as the number of applications received, whether requirements are specified, and the degree to which recruitment procedures are formalized. I argue that different contexts of employment provide different opportunity structures for discrimination, a finding with important theoretical and methodological implications. 相似文献
8.
Rodolphe Priam 《统计学通讯:理论与方法》2020,49(18):4468-4489
AbstractThe mean estimators with ratio depend on multiple auxiliary variables and unknown parameters in a finite population setting. We propose a new generalized approach with matrices for modeling the mutivariate mean estimators with two auxiliary variables. Our approach brings naturally a graphical analysis for comparing mean estimators. 相似文献
9.
刘林 《重庆大学学报(社会科学版)》2020,26(1):75-92
中国的市场仍旧存在某种程度的分割,如何突破这种市场分割到异地拓展市场是企业要考虑的现实问题。以前的研究主要是从省级层面或国家层面进行宏观分析。文章创新地从政企关系视角入手来考察市场分割情形下微观层面的企业异地市场拓展,也是首先把市场分割(和异地市场)分为省内(本市外)市场、省外市场和海外市场三个不同层面来研究的论文。用世界银行的调查数据从微观企业个体层面检验了企业异地市场拓展的可能。实证研究结果发现,市场分割确实阻碍了企业异地市场拓展,但这仅限于省内市场而不是省外市场。此外,市场分割是有方向性的,从地方保护主义严重的市场里走出来的企业更容易拓展异地市场,但此结论仅适用于国内市场拓展而不适用于海外市场拓展。良好的政企关系是有利于企业异地市场拓展的,但仅限于省外市场,对省内市场以及海外市场是无效的。文章解释了其中的原因,并分析了对于企业实践的启示。 相似文献
10.
Willem Schinkel 《The British journal of sociology》2020,71(3):556-571
Anyone trying to be a citizen has to pass through a set of practices trying to be a state. This paper investigates some of the ways testing practices calibrate citizens, and in doing so, perform “the state.” The paper focuses on three forms of citizenship testing, which it considers exemplary forms of “state work,” and which all, in various ways, concern “migration.” First, the constitution of a “border crossing,” which requires an identity test configured by deceptibility. Second, the Dutch asylum process, in which “being gay” can, in certain cases, be reason for being granted asylum, but where “being gay” is also the outcome of an examination organized by suspicion. And third, the Dutch measurement of immigrants’ “integration,” which is comprised of a testing process in which such factishes as “being a member of society” and “being modern” surface. Citizenship is analyzed in this paper as accrued and (re)configured along a migration trajectory that takes shape as a testing concours, meaning that subjects become citizens along a trajectory of testing practices. In contributing both to work on states and citizenship, and to work on testing, this paper thus puts forward the concept of citizenship testing as state work, where “state work is the term for that kind of labor that most knows itself as comparison, equivalency, and exchange in the social realm” (Harney, 2002, pp. 10–11). Throughout the testing practices discussed here, comparison, equivalency, and exchange figure prominently as the practical achievements of crafting states and citizens. 相似文献