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1.
Abstract

Recent work has emphasized the importance of evaluating estimates of a statistical functional (such as a conditional mean, quantile, or distribution) using a loss function that is consistent for the functional of interest, of which there is an infinite number. If forecasters all use correctly specified models free from estimation error, and if the information sets of competing forecasters are nested, then the ranking induced by a single consistent loss function is sufficient for the ranking by any consistent loss function. This article shows, via analytical results and realistic simulation-based analyses, that the presence of misspecified models, parameter estimation error, or nonnested information sets, leads generally to sensitivity to the choice of (consistent) loss function. Thus, rather than merely specifying the target functional, which narrows the set of relevant loss functions only to the class of loss functions consistent for that functional, forecast consumers or survey designers should specify the single specific loss function that will be used to evaluate forecasts. An application to survey forecasts of U.S. inflation illustrates the results.  相似文献   
2.
This article studies design selection for generalized linear models (GLMs) using the quantile dispersion graphs (QDGs) approach in the presence of misspecification in the link and/or linear predictor. The uncertainty in the linear predictor is represented by a unknown function and estimated using kriging. For addressing misspecified link functions, a generalized family of link functions is used. Numerical examples are shown to illustrate the proposed methodology.  相似文献   
3.
We show that the rearrangement algorithm (RA) introduced in Puccetti and Rüschendorf (2012 Puccetti, G., Rüschendorf, L. (2012). Computation of sharp bounds on the distribution of a function of dependent risks. Journal of Computational and Applied Mathematics 236(7):18331840.[Crossref], [Web of Science ®] [Google Scholar]) to compute distributional bounds can be used also to compute sharp lower and upper bounds on the expected value of a supermodular function of d random variables having fixed marginal distributions. Compared to the analytical methods existing in the literature the algorithm is widely applicable, more easily obtained and gives insight into the dependence structures attaining the bounds.  相似文献   
4.
Emergency material allocation is an important part of postdisaster emergency logistics that is significant for improving rescue effectiveness and reducing disaster losses. However, the traditional single‐period allocation model often causes local surpluses or shortages and high cost, and prevents the system from achieving an equitable or optimal multiperiod allocation. To achieve equitable allocation of emergency materials in the case of serious shortages relative to the demand by victims, this article introduces a multiperiod model for allocation of emergency materials to multiple affected locations (using an exponential utility function to reflect the disutility loss due to material shortfalls), and illustrates the relationship between equity of allocations and the cost of emergency response. Finally, numerical examples are presented to demonstrate both the feasibility and the usefulness of the proposed model for achieving multiperiod equitable allocation of emergency material among multiple disaster locations. The results indicate that the introduction of a nonlinear utility function to reflect the disutility of large shortfalls can make the material allocation fairer, and minimize large losses due to shortfalls. We found that achieving equity has a significant but not unreasonable impact on emergency costs. We also illustrate that using differing utility functions for different types of materials adds an important dimension of flexibility.  相似文献   
5.
Multivariate data arise frequently in biomedical and health studies where multiple response variables are collected across subjects. Unlike a univariate procedure fitting each response separately, a multivariate regression model provides a unique opportunity in studying the joint evolution of various response variables. In this paper, we propose two estimation procedures that improve estimation efficiency for the regression parameter by accommodating correlations among the response variables. The proposed procedures do not require knowledge of the true correlation structure nor does it estimate the parameters associated with the correlation. Theoretical and simulation results confirm that the proposed estimators are more efficient than the one obtained from the univariate approach. We further propose simple and powerful inference procedures for a goodness-of-fit test that possess the chi-squared asymptotic properties. Extensive simulation studies suggest that the proposed tests are more powerful than the Wald test based on the univariate procedure. The proposed methods are also illustrated through the mother’s stress and children’s morbidity study.  相似文献   
6.
Several attempts were made in the literature to generalize the notions based on univariate quantiles to higher dimensions. As quantile-based reliability concepts are receiving much attention, it is important to address these problems in the field of Reliability theory. In this paper, bivariate reliability concepts using the dependence structure are introduced. The properties and characterizations of the bivariate reliability concepts are presented; it includes the characterization based on the relationship between bivariate hazard rate and bivariate mean residual life. The bivariate reliability concepts in reversed time are also studied.  相似文献   
7.
康养旅游(wellness tourism)隶属于健康旅游(health tourism)的范畴,是新近国际旅游研究的热点领域。文章通过对康养旅游概念的源起及其流变的梳理,辨明了康养旅游与健康旅游、温泉疗法、疗养旅游、医疗旅游等相关概念的关系。研究表明,康养旅游的产品形式会根据不同国家和地区的资源禀赋、健康政策、消费市场的特点而产生变化,因此,不同地区的康养旅游内涵、构成与产品形式是学术界研究的焦点之一。而在康养旅游的功能分析上,主要聚焦于对人的身体、精神以及生活质量等方面。最后,康养旅游者出游前的动机、旅游中的体验与游后的满意度和行为意向构成了康养旅游者研究的主体内容。康养旅游是中国旅游业转型发展的一条可行道路,应从国家政策保障、目的地建设和公民健康观念入手,培育中国康养旅游市场,提升全民健康水平。同时,文章也为未来中国康养旅游的研究议题提出了相关建议。  相似文献   
8.
检察机关的宪法定位由其宪法地位和功能定位构成,《宪法》第3条第3款和第136条是检察机关宪法地位的主要依据,第134条是其功能定位依据。法律监督并非检察机关的专属职权,而是其应尽的义务。“法律监督机关”在整体上指专事维护法制统一和法律秩序稳定的国家机关,检察机关是目前唯一的法律监督机关。检察机关的调整职权应受宪法规范,立法是检察机关职权调整的必由之路,在保留检察机关、固守法律监督的职能定位、不违反宪法基本原则、不侵犯其他国家机关固有职权的前提下,一切国家机关违反宪法和法律的行为均可成为检察机关的监督对象。  相似文献   
9.
This paper reports the results of a laboratory experiment in which probability weighting functions for risky gains were elicited non-parametrically in over 500 incentivized subjects. I compared probability weights for monetary rewards to two less fungible domains involving vouchers for different types of consumption, inducing stronger or weaker (positive) emotions. The level of stakes was also manipulated. I found that the probability to win monetary rewards was weighted almost linearly in the high stakes condition, the probability to win vouchers associated with stronger positive affect was underweighted and the probability to win affect-poor vouchers was strongly underweighted. Substantial underweighting also prevailed in all three domains in the low stakes condition.  相似文献   
10.
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