首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   236篇
  免费   6篇
管理学   51篇
人才学   1篇
人口学   28篇
理论方法论   28篇
社会学   84篇
统计学   50篇
  2024年   1篇
  2023年   3篇
  2022年   4篇
  2021年   5篇
  2020年   10篇
  2019年   13篇
  2018年   7篇
  2017年   11篇
  2016年   11篇
  2015年   4篇
  2014年   6篇
  2013年   38篇
  2012年   23篇
  2011年   7篇
  2010年   8篇
  2009年   6篇
  2008年   7篇
  2007年   11篇
  2006年   3篇
  2005年   3篇
  2004年   8篇
  2002年   1篇
  2001年   3篇
  2000年   6篇
  1999年   5篇
  1998年   4篇
  1997年   2篇
  1996年   1篇
  1994年   4篇
  1993年   2篇
  1992年   4篇
  1991年   2篇
  1989年   1篇
  1985年   1篇
  1982年   1篇
  1981年   1篇
  1979年   2篇
  1978年   1篇
  1976年   1篇
  1975年   3篇
  1974年   1篇
  1973年   3篇
  1968年   4篇
排序方式: 共有242条查询结果,搜索用时 140 毫秒
81.
82.
One of the challenging problems in neuroimaging is the principled incorporation of information from different imaging modalities. Data from each modality are frequently analyzed separately using, for instance, dimensionality reduction techniques, which result in a loss of mutual information. We propose a novel regularization method, generalized ridgified Partially Empirical Eigenvectors for Regression (griPEER), to estimate associations between the brain structure features and a scalar outcome within the generalized linear regression framework. griPEER improves the regression coefficient estimation by providing a principled approach to use external information from the structural brain connectivity. Specifically, we incorporate a penalty term, derived from the structural connectivity Laplacian matrix, in the penalized generalized linear regression. In this work, we address both theoretical and computational issues and demonstrate the robustness of our method despite incomplete information about the structural brain connectivity. In addition, we also provide a significance testing procedure for performing inference on the estimated coefficients. Finally, griPEER is evaluated both in extensive simulation studies and using clinical data to classify HIV+ and HIV? individuals.  相似文献   
83.
The efficient and effective management of nursing personnel is of critical importance in a hospital's environment comprising a vast share of the operational costs. The adopted nurse workforce practices and policies highly affect the nurses' working conditions and the provided quality of care. Policy decisions on the staffing level have an impact on the outcome of the scheduling level and vice versa. Isolated reasoning typically leads to suboptimal decisions often resulting in ineffective outcomes of care. In order to overcome these inefficiencies, we propose in this paper a new integrative nurse staffing and shift scheduling approach. We test and assess the benefits of our approach in a reallife environment. Moreover, we examine the impact of several personnel policies on the staffing decision.  相似文献   
84.
The purpose of this article is to examine the role of the alignment between technological innovation effectiveness and operational effectiveness after the implementation of enterprise information systems, and the impact of this alignment on the improvement in operational performance. Confirmatory factor analysis was used to examine structural relationships between the set of observed variables and the set of continuous latent variables. The findings from this research suggest that the dimensions stemming from technological innovation effectiveness such as system quality, information quality, service quality, user satisfaction and the performance objectives stemming from operational effectiveness such as cost, quality, reliability, flexibility and speed are important and significantly well-correlated factors. These factors promote the alignment between technological innovation effectiveness and operational effectiveness and should be the focus for managers in achieving effective implementation of technological innovations. In addition, there is a significant and direct influence of this alignment on the improvement of operational performance. The principal limitation of this study is that the findings are based on investigation of small sample size.  相似文献   
85.
Based on an administrative census of the 267,116 migrants registered for the 2017 presidential elections and a survey applied to 4771 migrants, we conclude that (1) the electoral participation of migrants shows a significant gender gap, with women participating in a higher proportion; (2) migrants who registered earlier in the electoral registers, are more likely to vote compared to the rest; (3) when migrants come from countries that implement compulsory voting, they increase their likelihood of voting in the receiving country; (4) the declaration of wanting to remain in Chile and not return to their countries of origin or migrate to another country increases the probability of voting, and the same happens with married migrants, with Chilean children, with a Chilean partner, and with a better economic situation; (5) social capital has a positive influence on electoral participation.  相似文献   
86.
In this paper we aim at assessing the outcomes of the 2007 Italian reform of the complementary social security scheme and at identifying the determinants behind them. The reform provided workers with relevant incentives to switch the investment of about 7 per cent of their gross yearly wages from a firm‐managed scheme (which took the form of a termination indemnity payment, the Trattamento di Fine Rapporto scheme) to an external pension fund. We provide a theoretical framework to model the workers' problem of choosing between these two different forms of complementary social security schemes and we then perform an agent‐based simulation taking into account all the details of the reform. Differently from previous contributions, we stress the impact that the investment decision has on the financial health of firms and, consequently, on workers' employment stability. Our simulations are able to replicate the Italian data in terms of adhesion rates to complementary social security and also to identify some of the key determinants of that outcome, such as fiscal incentives, individual preferences, the working of both the Italian labour and the financial markets and the productive structure of the Italian economy.  相似文献   
87.
We consider the random variable X that is not Gaussian but for which X c , where c = (2k + 1)/(2j + 1) with k, j ? {0, 1,…}, is approximately Gaussian. A variable of this type is used to model the errors made by meteorologists when forecasting temperatures.  相似文献   
88.
This paper addresses multiple comparisons in the presence of both a negative and a positive control. The methodology of the three-arm trial is extended to the case of many experimental treatment arms or different doses of a compound. In contrast to the classic three-arm trial, the focus is on the family-wise error type I. Normally distributed data with either homogeneous or heterogeneous group variances are considered. Explicit criteria for an optimal allocation are proposed. Depending on the pattern of heterogeneity, remarkably unbalanced designs are power-optimal. As an example, the method will be applied to a toxicological experiment.  相似文献   
89.
In this paper, we analyzed two laboratories of liquid chromatography (LC), separation technique of mixtures and identification of its components, in order to identify projectual gaps relating to the environment and the working station. The methodology used was the ergonomic analysis with interactional and participatory techniques applied during the activity performance. This work incorporated and adapted the concept developed by Alexander (1979)--pattern languages--passing from architectural projects to workstations project and physical arrangement of the work environment. The adaptation of the concept resulted in a list of recommendations, requirements and concepts that have brought design solutions for the problematic aspects observed in the ergonomic analysis. The employed methodology, strongly supported in ergonomics principles, and in interactional and participatory techniques, contributed to achieve our gold that is what we now call Conceptual Standards. The patterns go beyond of a usual model of book a of ergonomics specification, once incorporating the viewpoint of the end user, it is also a set of best project practices and of project management in conception ergonomics.  相似文献   
90.
Although sexual cues produce stronger neural activation in men than in women, mechanisms underlying this differential response are unclear. We examined the relationship of sensation seeking and the brain’s response to sexual stimuli across gender in 27 subjects (14 men, M = 25.2 years, SD = 3.6, 85.2% Caucasian) who underwent functional magnetic resonance imaging (fMRI) while viewing sexual and nonsexual images. Whole-brain corrected significant clusters of regional activation were extracted and associated with gender, sensation seeking, and sexual behaviors. Men responded more to sexual than nonsexual images in the anterior cingulate/medial prefrontal cortex (ACC/mPFC), anterior insula/lateral orbitofrontal cortex, bilateral amygdala, and occipital regions. Sensation seeking related positively to ACC/mPFC (r = 0.65, p = 0.01) and left amygdala (r = 0.66, p = 0.01) response in men alone, with both of these correlations being significantly larger in men than in women (ps < 0.03). The relationship between brain responses and self-reported high-risk and low-risk sexual behaviors showed interesting, albeit nonsignificant, gender-specific trends. These findings suggest the relationship between sexual responsivity, sensation seeking, and sexual behavior is gender specific. This study indicates a need to identify the gender-specific mechanisms that underlie sexual responsivity and behaviors. In addition, it demonstrates that the nature of stimuli used to induce positive mood in imaging and other studies should be carefully considered.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号