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61.
从理论层面揭示区域一体化影响城市土地利用效率(ULUE)的内在机理,构建区域一体化背景下“规模+结构+集聚”的ULUE测度体系,并综合利用小波神经网络、空间分异模型和空间回归分析探索2003-2015年长江中游城市群ULUE的空间关联特征及其影响因素。结果发现:①区域一体化背景下长江中游城市群ULUE从2003的0.561 4增长至2015年的0.811 1,且呈现出明显的区域差异。②ULUE并非随机分布,而是具有空间上的关联特征和集群趋势。且由于不同集聚区内扩散效应在空间上渗透不均衡,其关联性主要表现为空间依赖性和空间异质性。③区域一体化背景下长江中游城市群ULUE在空间关联上具有“近水楼台先得月”和“门当户对”的特征,地理位置的空间相邻、投资消费结构和产业结构的相似是其空间关联的主要成因。 相似文献
62.
通过文献资料、问卷调查、数理统计等方法对浙江省高职大学生体育价值观与体育活动体验的相关性进行了调查研究。结果显示,浙江省高职大学生的体育价值观学生认为体育能愉悦心情、促进健康、丰富生活。根据调查数据,对不同类别的高职大学生的体育价值观和体育活动的体验进行了分析与比较。 相似文献
63.
近年来,隐性课程的研究成为一个热点问题,特别是在高等教育领域备受关注。从教育界对隐性课程的研究角度(隐性课程的概念、特征、功能、建设与管理几个方面)切入,对实践中存在的一些问题进行分析,以期对以后的研究有所帮助。 相似文献
64.
Gabriel Escarela Luis Carlos Pérez-Ruíz Russell J. Bowater 《Journal of applied statistics》2009,36(6):647-657
A fully parametric first-order autoregressive (AR(1)) model is proposed to analyse binary longitudinal data. By using a discretized version of a copula, the modelling approach allows one to construct separate models for the marginal response and for the dependence between adjacent responses. In particular, the transition model that is focused on discretizes the Gaussian copula in such a way that the marginal is a Bernoulli distribution. A probit link is used to take into account concomitant information in the behaviour of the underlying marginal distribution. Fixed and time-varying covariates can be included in the model. The method is simple and is a natural extension of the AR(1) model for Gaussian series. Since the approach put forward is likelihood-based, it allows interpretations and inferences to be made that are not possible with semi-parametric approaches such as those based on generalized estimating equations. Data from a study designed to reduce the exposure of children to the sun are used to illustrate the methods. 相似文献
65.
The purpose of this article is to compare efficiencies of several cluster randomized designs using the method of quantile dispersion graphs (QDGs). A cluster randomized design is considered whenever subjects are randomized at a group level but analyzed at the individual level. A prior knowledge of the correlation existing between subjects within the same cluster is necessary to design these cluster randomized trials. Using the QDG approach, we are able to compare several cluster randomized designs without requiring any information on the intracluster correlation. For a given design, several quantiles of the power function, which are directly related to the effect size, are obtained for several effect sizes. The quantiles depend on the intracluster correlation present in the model. The dispersion of these quantiles over the space of the unknown intracluster correlation is determined, and then depicted by the QDGs. Two applications of the proposed methodology are presented. 相似文献
66.
The data collection process and the inherent population structure are the main causes for clustered data. The observations in a given cluster are correlated, and the magnitude of such correlation is often measured by the intra-cluster correlation coefficient. The intra-cluster correlation can lead to an inflated size of the standard F test in a linear model. In this paper, we propose a solution to this problem. Unlike previous adjustments, our method does not require estimation of the intra-class correlation, which is problematic especially when the number of clusters is small. Our simulation results show that the new method outperforms the existing methods. 相似文献
67.
Evgeny D. Maslennikov Alexey V. Sulimov Igor A. Savkin Marina A. Evdokimova Dmitry A. Zateyshchikov Valery V. Nosikov 《Journal of applied statistics》2015,42(1):71-87
The article focuses on the application of the Bayesian networks (BN) technique to problems of personalized medicine. The simple (intuitive) algorithm of BN optimization with respect to the number of nodes using naive network topology is developed. This algorithm allows to increase the BN prediction quality and to identify the most important variables of the network. The parallel program implementing the algorithm has demonstrated good scalability with an increase in the computational cores number, and it can be applied to the large patients database containing thousands of variables. This program is applied for the prediction for the unfavorable outcome of coronary artery disease (CAD) for patients who survived the acute coronary syndrome (ACS). As a result, the quality of the predictions of the investigated networks was significantly improved and the most important risk factors were detected. The significance of the tumor necrosis factor-alpha gene polymorphism for the prediction of the unfavorable outcome of CAD for patients survived after ACS was revealed for the first time. 相似文献
68.
Guangyu Mao 《统计学通讯:理论与方法》2017,46(20):10036-10050
This article develops a new test based on Spearman’s rank correlation coefficients for total independence in high dimensions. The test is robust to the non normality and heavy tails of the data, which is a merit that is not shared by the existing tests in literature. Simulation results suggest that the new test performs well under several typical null and alternative hypotheses. Besides, we employ a real data set to illustrate the use of the new test. 相似文献
69.
In this paper, we propose a new partial correlation, the so-called composite quantile partial correlation, to measure the relationship of two variables given other variables. We further use this correlation to screen variables in ultrahigh-dimensional varying coefficient models. Our proposed method is fast and robust against outliers and can be efficiently employed in both single index variable and multiple index variable varying coefficient models. Numerical results indicate the preference of our proposed method. 相似文献
70.
This study considers a fully-parametric but uncongenial multiple imputation (MI) inference to jointly analyze incomplete binary response variables observed in a correlated data settings. Multiple imputation model is specified as a fully-parametric model based on a multivariate extension of mixed-effects models. Dichotomized imputed datasets are then analyzed using joint GEE models where covariates are associated with the marginal mean of responses with response-specific regression coefficients and a Kronecker product is accommodated for cluster-specific correlation structure for a given response variable and correlation structure between multiple response variables. The validity of the proposed MI-based JGEE (MI-JGEE) approach is assessed through a Monte Carlo simulation study under different scenarios. The simulation results, which are evaluated in terms of bias, mean-squared error, and coverage rate, show that MI-JGEE has promising inferential properties even when the underlying multiple imputation is misspecified. Finally, Adolescent Alcohol Prevention Trial data are used for illustration. 相似文献