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81.
给出了有单位元的环上的余平坦模和余平坦分解概念,得到了一系列结果。  相似文献   
82.
Two open problems are described for the hyperbolic secant distribution, as a special case of the more general Meixner hypergeomet-ric distribution. The first concerns the completeness of the family of functions sech θ x , θ≥ 0. The second concerns the characterization of the class of canonical correlation sequences in bivariate distributions with marginals sech θ x , sech θ y. In both cases some partial results are put forward.  相似文献   
83.
84.
In Canada, there is a lack of research on gambling among the older adults from ethnic minority groups, especially the older Chinese. In this study, two research questions were used to examine gambling among the older Chinese: (1) What is the pattern of gambling among the older Chinese in Canada? (2) What are the predictors associated with gambling among the older Chinese in Canada? The data for this study were collected as part of a multi-site study on health and well-being of 2272 older Chinese in Canada. Four main questions related to gambling were used in this study. Among the 2257 participants who answered the questions on gambling, 26.6% of them reported that they gambled. Results of the hierarchical logistic regression analysis showed that being male, having lived in Canada longer, having a higher level of social support, having more service barriers, and having a stronger level of Chinese ethnic identity would increase the probability for an older Chinese to participate in gambling. Conversely, having a post-secondary and above level of education and having a higher level of life satisfaction would reduce one’s probability of gambling. Although city of residency was also significant in predicting gambling, further analysis showed that its effect was actually caused by other factors including services barriers, social support, life satisfaction, Chinese ethnic identity, and education.  相似文献   
85.
消费社会的商业和文化逻辑推动中国电影专注于符号价值的生产,形成了新的美学形态和营销理念。在大众媒介帮助下,围绕电影的符号消费,一个个具有独特气质的排他性文化团体建立了起来。符号价值冲击着中国电影的大众属性,造成了电影文化生态的失衡,影响了中国电影的文化公平。现实主义电影以内容为王,提供共通的体验,是一个有效的解决策略。  相似文献   
86.
In this article, we investigate the limitations of traditional quantile function estimators and introduce a new class of quantile function estimators, namely, the semi-parametric tail-extrapolated quantile estimators, which has excellent performance for estimating the extreme tails with finite sample sizes. The smoothed bootstrap and direct density estimation via the characteristic function methods are developed for the estimation of confidence intervals. Through a comprehensive simulation study to compare the confidence interval estimations of various quantile estimators, we discuss the preferred quantile estimator in conjunction with the confidence interval estimation method to use under different circumstances. Data examples are given to illustrate the superiority of the semi-parametric tail-extrapolated quantile estimators. The new class of quantile estimators is obtained by slight modification of traditional quantile estimators, and therefore, should be specifically appealing to researchers in estimating the extreme tails.  相似文献   
87.
Brownian motion has been used to derive stopping boundaries for group sequential trials, however, when we observe dependent increment in the data, fractional Brownian motion is an alternative to be considered to model such data. In this article we compared expected sample sizes and stopping times for different stopping boundaries based on the power family alpha spending function under various values of Hurst coefficient. Results showed that the expected sample sizes and stopping times will decrease and power increases when the Hurst coefficient increases. With same Hurst coefficient, the closer the boundaries are to that of O'Brien-Fleming, the higher the expected sample sizes and stopping times are; however, power has a decreasing trend for values start from H = 0.6 (early analysis), 0.7 (equal space), 0.8 (late analysis). We also illustrate study design changes using results from the BHAT study.  相似文献   
88.
Introduction: We use data from Spain on roads and motorways traffic accidents in May 2004 to quantify the statistical association between quick medical response time and mortality rate. Method: Probit and logit parameters are estimated by a Bayesian method in which samples from the posterior densities are obtained through an MCMC simulation scheme. We provide posterior credible intervals and posterior partial effects of a quick medical response at several time levels over which we express our prior beliefs. Results: A reduction of 5 min, from a 25-min response-time level, is associated with lower posterior probabilities of death in roads and motorways accidents of 24% and 30%, respectively.  相似文献   
89.
Linear models constitute the primary statistical technique for any experimental science. A major topic in this area is the detection of influential subsets of data, that is, of observations that are influential in terms of their effect on the estimation of parameters in linear regression or of the total population parameters. Numerous studies exist on radiocarbon dating which propose a value consensus and remove possible outliers after the corresponding testing. An influence analysis for the value consensus from a Bayesian perspective is developed in this article.  相似文献   
90.
In this article, we present a general model for predicting the fatigue behavior for any stress level and amplitude using the exponential model. Based on the Wöhler field for fixed stress level, a compatibility functional equation enables us to derive the general model with eight parameters. The problem of parameter estimation is then discussed and some methods are described. Some examples are finally presented to illustrate the derived model and the proposed methods of estimation.  相似文献   
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