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121.
学会的基本属性和活动方式与协同创新要求相契合,使其能够在推动协同创新、实施科技创新驱动发展战略中发挥重要作用。协同创新是一个复杂的系统工程,学会在政府、科学家、企业、金融资本等创新活动主体间扮演沟通联系人、协调者、润滑剂的角色,构建跨学科、跨大类学科甚至跨文理界限的学会联盟是协同创新活动发展的必然。为提升学会学术研究、协同创新能力,政府部门、企业、高等院校、科研部门、私人基金会等应支持学会建设向着有利于协同创新的方向发展,学会应进一步推动实体化建设,面向市场,服务社会。  相似文献   
122.
This paper considers the problem where the linear discriminant rule is formed from training data that are only partially classified with respect to the two groups of origin. A further complication is that the data of unknown origin do not constitute an observed random sample from a mixture of the two under- lying groups. Under the assumption of a homoscedastic normal model, the overall error rate of the sample linear discriminant rule formed by maximum likelihood from the partially classified training data is derived up to and including terms of the first order in the case of univariate feature data. This first- order expansion of the sample rule so formed is used to define its asymptotic efficiency relative to the rule formed from a completely classified random training set and also to the rule formed from a completely unclassified random set.  相似文献   
123.
This article presents a Bayesian method to reconstruct the centerline in noisy data using B-spline curves. The method is illustrated on simulated two- and three-dimensional data and is applied to recover the centerline of the colon in single photon emission computed tomography images.  相似文献   
124.
This article develops two block bootstrap-based panel predictability test procedures that are valid under very general conditions. Some of the allowable features include cross-sectional dependence, heterogeneous predictive slopes, persistent predictors, and complex error dynamics, including cross-unit endogeneity. While the first test procedure tests if there is any predictability at all, the second procedure determines the units for which predictability holds in case of a rejection by the first. A weak unit root framework is adopted to allow persistent predictors, and a novel theory is developed to establish asymptotic validity of the proposed bootstrap. Simulations are used to evaluate the performance of our tests in small samples, and their implementation is illustrated through an empirical application to stock returns.  相似文献   
125.
An extended single‐index model is considered when responses are missing at random. A three‐step estimation procedure is developed to define an estimator for the single‐index parameter vector by a joint estimating equation. The proposed estimator is shown to be asymptotically normal. An algorithm for computing this estimator is proposed. This algorithm only involves one‐dimensional nonparametric smoothers, thereby avoiding the data sparsity problem caused by high model dimensionality. Some simulation studies are conducted to investigate the finite sample performances of the proposed estimators.  相似文献   
126.
We introduce two classes of multivariate log-skewed distributions with normal kernel: the log canonical fundamental skew-normal (log-CFUSN) and the log unified skew-normal. We also discuss some properties of the log-CFUSN family of distributions. These new classes of log-skewed distributions include the log-normal and multivariate log-skew normal families as particular cases. We discuss some issues related to Bayesian inference in the log-CFUSN family of distributions, mainly we focus on how to model the prior uncertainty about the skewing parameter. Based on the stochastic representation of the log-CFUSN family, we propose a data augmentation strategy for sampling from the posterior distributions. This proposed family is used to analyse the US national monthly precipitation data. We conclude that a high-dimensional skewing function lead to a better model fit.  相似文献   
127.
This study sheds light on women's perceptions of pregnancy‐related discrimination committed by the discriminated woman's immediate leader. The purpose is to show how women describe this perception during pregnancy and after their return to working life after maternity leave. Further, the study explores the ways in which the quality of the leader–follower relationship is revealed during the narration process. The research draws on five individual stories, collected in two rounds of interviews. Representations of several kinds of discriminatory practices can be found in the narratives and reveal that even being a partner in a good‐quality leader–follower relationship does not necessarily protect a woman from pregnancy‐related discrimination. However, women involved in a high‐quality leader–follower relationship described their perceptions in a more positive manner than those in a low‐quality relationship. The contribution of the article to the literature is twofold: firstly, the results challenge the traditional view that high‐quality leader–member exchange relationships lead to positive outcomes. Secondly, examining the different ways in which people describe their perceptions of discrimination deepens our understanding of the equality problems that working women face.  相似文献   
128.
This work considers two specific estimation techniques for the family-specific proportional hazards model and for the population-averaged proportional hazards model. So far, these two estimation procedures were presented and studied under the gamma frailty distribution mainly because of its simple interpretation and mathematical tractability. Modifications of both procedures for other frailty distributions, such as the inverse Gaussian, positive stable and a specific case of discrete distribution, are presented. By extensive simulations, it is shown that under the family-specific proportional hazards model, the gamma frailty model appears to be robust to frailty distribution mis-specification in both bias and efficiency loss in the marginal parameters. The population-averaged proportional hazards model, is found to be robust under the gamma frailty model mis-specification only under moderate or weak dependency within cluster members.  相似文献   
129.
It is essential to test the goodness of fit of the model before making inferences based on it. Multilevel modeling of ordinal categorical responses is not as developed as for continuous responses. Assessing model adequacy in terms of the goodness of fit with ordinal categorical responses is still being developed and no satisfactory tests are available so far. As a consequence of that, this study concentrates on developing such a goodness of fit test for Multilevel Proportional Odds models and to study the properties of the test.  相似文献   
130.
现阶段,随着图书馆馆藏图书的增多,使中文编目数据的工作量逐渐增大,为了进一步提高工作效率和质量,有必要对中文编目数据过程中难以控制的因素进行分析,并采取相应的手段加以控制,就中文编目数据工作过程中难以控制的因素展开探讨。  相似文献   
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