中国艾滋病配偶间传播的现状与影响因素

自2003年以来,艾滋病经性传播的比例逐年上升,2007年首次超过吸毒成为流行的最主要原因。随着性接触成为主要传播渠道,女性感染人数大幅上升,所占比例从1998年的15．3％上升至2007年的28．7％。国外的许多研究表明,相当大比例的艾滋病感染者仍在发生无保护的性行为,这使他们成为艾滋病新发感染的重要来源。     

高师学生职业素质发展测评系统

本文以国内外有关教师素质的最新理论为指导,在经过广泛调查和统计分析的基础上,提出了一个包含学科知识与能力、教育教学能力、职业基础知识与能力、职业人格、基础心理素质和教育实习行为表现等内容的高师学生职业素质发展测评系统,该系统结构合理、可操作性强,能较好地满足高师教育改革的需要     

Copula‐based semiparametric analysis for time series data with detection limits

The analysis of time series data with detection limits is challenging due to the high‐dimensional integral involved in the likelihood. Existing methods are either computationally demanding or rely on restrictive parametric distributional assumptions. We propose a semiparametric approach, where the temporal dependence is captured by parametric copula, while the marginal distribution is estimated non‐parametrically. Utilizing the properties of copulas, we develop a new copula‐based sequential sampling algorithm, which provides a convenient way to calculate the censored likelihood. Even without full parametric distributional assumptions, the proposed method still allows us to efficiently compute the conditional quantiles of the censored response at a future time point, and thus construct both point and interval predictions. We establish the asymptotic properties of the proposed pseudo maximum likelihood estimator, and demonstrate through simulation and the analysis of a water quality data that the proposed method is more flexible and leads to more accurate predictions than Gaussian‐based methods for non‐normal data. The Canadian Journal of Statistics 47: 438–454; 2019 © 2019 Statistical Society of Canada     

Design selection for strong orthogonal arrays

Strong orthogonal arrays (SOAs) were recently introduced and studied as a class of space‐filling designs for computer experiments. An important problem that has not been addressed in the literature is that of design selection for such arrays. In this article, we conduct a systematic investigation into this problem, and we focus on the most useful SOA(n,m,4,2 + )s and SOA(n,m,4,2)s. This article first addresses the problem of design selection for SOAs of strength 2+ by examining their three‐dimensional projections. Both theoretical and computational results are presented. When SOAs of strength 2+ do not exist, we formulate a general framework for the selection of SOAs of strength 2 by looking at their two‐dimensional projections. The approach is fruitful, as it is applicable when SOAs of strength 2+ do not exist and it gives rise to them when they do. The Canadian Journal of Statistics 47: 302–314; 2019 © 2019 Statistical Society of Canada     

Dynamic optimal capital growth of diversified investment

We investigate the problem of dynamic optimal capital growth of diversified investment. A general framework that the trader maximize the expected log utility of long-term growth rate of initial wealth was developed. We show that the trader's fortune will exceed any fixed bound when the fraction is chosen less than critical value. But, if the fraction is larger than that value, ruin is almost sure. In order to maximize wealth, we should choose the optimal fraction at each trade. Empirical results with real financial data show the feasible allocation. The larger the fraction and hence the larger the chance of falling below the desired wealth growth path.     

Posterior consistency for the spectral density of non-Gaussian stationary time series

Various nonparametric approaches for Bayesian spectral density estimation of stationary time series have been suggested in the literature, mostly based on the Whittle likelihood approximation. A generalization of this approximation involving a nonparametric correction of a parametric likelihood has been proposed in the literature with a proof of posterior consistency for spectral density estimation in combination with the Bernstein–Dirichlet process prior for Gaussian time series. In this article, we will extend the posterior consistency result to non-Gaussian time series by employing a general consistency theorem for dependent data and misspecified models. As a special case, posterior consistency for the spectral density under the Whittle likelihood is also extended to non-Gaussian time series. Small sample properties of this approach are illustrated with several examples of non-Gaussian time series.     

Senior centres in the lives of older Americans: implications for Chinese older adults

As a critical community resource, the senior centre has provided older Americans with a wide array of recreational, nutritional, health, and social service programmes. Funding resources include the Older Americans Act allocations, local organisations and governments, national charities, voluntary associations, and religious associations. The types of programmes offered at a senior centre reflect two models: social agency model or voluntary organisation model. The five most popular programmes are nutrition, health and fitness, recreation, volunteering, and social services. Participation in senior centre activities has positive impacts on the overall well-being of older adult participants. With the rapid growth in the ageing population and improved life expectancy in China, senior centres may serve as a focal point for Chinese older adults by providing a broad spectrum of social services to enhance the well-being of community-dwelling older adults, to support their independence and dignity, and to facilitate ageing in place in later life.     

Citizens' attitudes towards economic insecurity and government after the 2007 financial tsunami: A Hong Kong and Taiwan comparison

Wang KY‐T, Wong C‐k, Tang K‐L. Citizens' attitudes towards economic insecurity and government after the 2007 financial tsunami: A Hong Kong and Taiwan comparison The purpose of this study was to investigate people's attitudes to economic insecurity and government in Hong Kong and Taiwan after the financial tsunami of 2007. Random sampling telephone surveys were conducted in July 2009. These are the main conclusions: First, the most vulnerable groups hurt by the financial crisis were low‐income families and people who had lost their job or were afraid of losing it. This implies that the old policy issue of social stratification and the emerging policy issue of employment insecurity coexisted during the financial crisis. Second, personal experiences of economic insecurity had an influence on people's perceptions of the severity of the economic crisis at the societal level. Third, citizens had ambivalent feelings about public interventions during the crisis. Fourth, there were both convergence and divergence between Hong Kong and Taiwan with regard to attitudes to particular issues. The policy implications of these findings are discussed in the final section of this article.     

Bayesian analysis under accelerated failure time models with error-prone time-to-event outcomes

Lifetime Data Analysis - We consider accelerated failure time models with error-prone time-to-event outcomes. The proposed models extend the conventional accelerated failure time model by allowing...