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941.
When describing a failure time distribution, the mean residual life is sometimes preferred to the survival or hazard rate. Regression analysis making use of the mean residual life function has recently drawn a great deal of attention. In this paper, a class of mean residual life regression models are proposed for censored data, and estimation procedures and a goodness-of-fit test are developed. Both asymptotic and finite sample properties of the proposed estimators are established, and the proposed methods are applied to a cancer data set from a clinic trial. 相似文献
942.
Yanqing Sun 《Lifetime data analysis》2010,16(2):271-298
In a longitudinal study, an individual is followed up over a period of time. Repeated measurements on the response and some time-dependent covariates are taken at a series of sampling times. The sampling times are often irregular and depend on covariates. In this paper, we propose a sampling adjusted procedure for the estimation of the proportional mean model without having to specify a sampling model. Unlike existing procedures, the proposed method is robust to model misspecification of the sampling times. Large sample properties are investigated for the estimators of both regression coefficients and the baseline function. We show that the proposed estimation procedure is more efficient than the existing procedures. Large sample confidence intervals for the baseline function are also constructed by perturbing the estimation equations. A simulation study is conducted to examine the finite sample properties of the proposed estimators and to compare with some of the existing procedures. The method is illustrated with a data set from a recurrent bladder cancer study. 相似文献
943.
AbstractIn this article, in the framework of sublinear expectation initiated by Peng, we derive a strong law of large numbers (SLLN) for negatively dependent and non identical distributed random variables. This result includes and extends some existing results. Furthermore, we give two examples of our result for applications. 相似文献
944.
A key assumption of general strain theory (GST) is that various factors condition the effects of strains on crime. Past research examining this conditioning hypothesis tended to focus on youth samples and use gender as a control variable. Using survey data from Chinese female inmates, this study tests the strain–crime relationship posited in GST as well as the hypothesized effects of the conditioning factors. Regression results show that different types of strains have distinct effects on respondents’ odds to commit violent over property crimes. Conditioning factors are found to moderate the strengths of strains toward respondents’ likelihood to commit property crimes over violent crimes. 相似文献
945.
Zhengyu Zhang Kristen L. Farris Mao‐Chia Sun Ren M. Dailey Erin E. Donovan 《Journal of research on adolescence》2020,30(3):800-816
Guided by self‐determination theory, the aim of this study was to examine whether adolescents’ autonomous motivation for making healthy diet choices mediates the association between parenting practices regarding diet and adolescent food choices. We analyzed data from the NCI FLASHE study, a survey of demographically diverse parents and their adolescent children (N = 1,646 dyads). Path models supported self‐determination theory’s assertion that indirect, encouraging parenting practices fostered internal motivation; in contrast, regulation was both positively and negatively linked to motivation depending on the model. Models also yielded direct paths between parenting practices and healthy and unhealthy diet choices. Overall, regardless of what predicted motivation, adolescents’ autonomous motivation was linked with their consumption of healthier foods and drinks. As such, cultivating a sense of internal motivation during these formative years may put young people on a path toward healthy patterns of self‐regulation later in life. 相似文献
946.
Urban Ecosystems - Aiming to explore the species-specific responses of biomass allocation and whole-tree transpiration in urban trees to pavement and drought, a field manipulation experiment grew... 相似文献
947.
Huiqiong Li Han Zhang Liang Zhu Ni Li Jianguo Sun 《Revue canadienne de statistique》2020,48(3):499-517
The additive hazards model is one of the most commonly used regression models in the analysis of failure time data and many methods have been developed for its inference in various situations. However, no established estimation procedure exists when there are covariates with missing values and the observed responses are interval-censored; both types of complications arise in various settings including demographic, epidemiological, financial, medical and sociological studies. To address this deficiency, we propose several inverse probability weight-based and reweighting-based estimation procedures for the situation where covariate values are missing at random. The resulting estimators of regression model parameters are shown to be consistent and asymptotically normal. The numerical results that we report from a simulation study suggest that the proposed methods work well in practical situations. An application to a childhood cancer survival study is provided. The Canadian Journal of Statistics 48: 499–517; 2020 © 2020 Statistical Society of Canada 相似文献
948.
孙建新 《绍兴文理学院学报》1990,(4)
本文应用 H.L.P.均值于样本,构造了广义样本均值;为了将它用于参数估计,根据替换法则(Substitution rule),推广了数学期望的定义,同时引入新的无偏性.最后应用广义数学期望的基本性质推出若干结论(定理1~4),说明在参数估计方面应用广义均值是有意义的. 相似文献
949.
论通货膨胀对投资决策的影响 总被引:1,自引:0,他引:1
孙静娟 《深圳大学学报(人文社会科学版)》1995,(1)
企业进行投资决策时,通常只考虑货币的时间价值,而不考虑通货膨胀,本文从理论和决策方法上探讨了通货膨胀对投资决策的影响。 相似文献
950.
本文在对燃煤电站锅炉对流受热面受飞灰磨损进行理论分析的基础上,建立了热态下飞灰冲蚀受热面磨损特性的数学模型,并通过试验研究求出在不同粒子冲刷速度下,质量相对磨损量与受热面温度变化之间的函数关系式. 相似文献