Multiple event times in the presence of informative censoring: modeling and analysis by copulas

Motivated by a breast cancer research program, this paper is concerned with the joint survivor function of multiple event times when their observations are subject to informative censoring caused by a terminating event. We formulate the correlation of the multiple event times together with the time to the terminating event by an Archimedean copula to account for the informative censoring. Adapting the widely used two-stage procedure under a copula model, we propose an easy-to-implement pseudo-likelihood based procedure for estimating the model parameters. The approach yields a new estimator for the marginal distribution of a single event time with semicompeting-risks data. We conduct both asymptotics and simulation studies to examine the proposed approach in consistency, efficiency, and robustness. Data from the breast cancer program are employed to illustrate this research.

     

论印度在中国对外政策中的地位

国内官方和学术界尚未系统论述过一国在我对外政策中的地位问题。本文将其分为至关重要、非常重要和比较重要三个等级,认为印度在周边外交中地位至关重要,在大国外交中地位比较重要,在发展中国家外交中地位非常重要。     

优选方案定量评价模型研究

在确定评价指标体系的基础上，如何对若干事物或方案进行选优是一个十分有意义的问题．作者利用模糊多目标决策对此进行研究，并通过实例说明该方法的有效性与实用性．     

载波相位平滑GPS伪码伪距的研究

分析了全球定位系统接收机可获取的观测量。给出了载波相位平滑伪码伪距的一个递归算法结构。讨论了平滑算法初值的设定和构造伪距前向预测值，并对各种情况进行了统计分析。文中还给出了平滑算法的性能评估，结论表明载波相位平滑技术可大大改善伪距观测精度。改善程度与该算法中的权重因子和递归时间密切相关     

论需求不足

宏观经济需求不足是我国目前经济发展所面临的主要问题 ,其存在的外在原因是消费不旺 ,这主要受到了不良的收入预期和不良的支出预期影响。而宏观需求不足的内在原因是产品质量的品种结构不合理 ,解决宏观需求不足 ,必须通过扩大需求和调整供给结构来解决。     

Risk,trust and knowledge networks in farmers’ learning

This study reports on New Zealand dairy farmers’ access to and use of information as mediated through conditions of risk and trust within the context of their interpersonal social networks. We located participants’ reports of their information use within their perceived environments of trust and risk, following Giddens's [1990. The consequences of modernity. Polity Press, Stanford, CA] typology of trust and risk in pre-modernity and modernity. The research participants were constant users of interpersonal and print information from numerous sources, and monitored their incoming data in the light of strategic needs, reflecting their roles as both farming practitioners and business owners. Socio-spatial knowledge networks (SSKNs) combine individuals’ explanatory cognitive models of information acquisition and use with a micro-geographical analysis of their interpersonal networks. The participants showed characteristics of pre-modern, modern and even post-modern society in respect of their use of complex interactional forms, as well as a blending of individualistic and communitarian practices and concerns in their professional and personal lives.     

丙硫咪唑驱绦虫试验

作者首次应用不同剂量的丙硫咪唑进行驱除建鲤绦虫试验。用丙硫咪唑20mg/Kg体重驱除建鲤肠道中的九江头槽绦虫,驱虫率达96.5％以上,效果好,安全可靠。     

政府治理范式的成本分析

政府治理范式的区别会导致政府成本的差异。与工业社会相适应的政府治理范式显得僵化、迟钝,容易导致高成本、低效率。建构现代责任政府、创新政府治理范式、优化政府治理的成本结构,是中国降低政府成本,提升政府绩效的基本实现路径。     

A case study of the labour market status of recent mainland Chinese immigrants,metropolitan Toronto

"This article focuses on an analysis of the labour market status of recent MCIs [mainland Chinese immigrants to Canada], taking into account such factors as gender, educational attainment, language proficiency and period of arrival (or length of residence in Canada), and uses Metropolitan Toronto as a case study. The effect of each factor on MCIs' labour market status will be analysed separately, followed by two logit models examining the simultaneous effects of the factors and their relative importance." (SUMMARY IN FRE AND SPA)     

On changes in the age composition of the population and policy options for population planning

This analysis, based on 1978 data from official household registers, suggests that the 1983-2000 period will be critical for China's efforts to control population growth. If declines in the fertility rate are maintained, the possibility of stabilizing China's population at 800-900 million in the next century is feasible. If the population is to be kept under 1.2 billion by the year 2000, the general fertility rate must be lowered to 1.8 in 1985 and must decline 0.1 each 5 years thereafter until it reaches 1.5 in the year 2000. Once population growth is brought under control, it will be necessary to address consequent increases in the median age of the population. Those over 65 years of age will comprise 7.1-7.8% of the population in the year 2000, depending on whether fertility rates are low or high. The medium projection includes a population of 1.211 billion in the year 2000, approaching the peak value but allowing the fertility rate to rise slowly to guard against excessive aging of the population. The proportion of those over 65 years of age reaches a peak value of 20.2% in the year 2040. Overall, these projections suggest a "golden age" continuing until about 2020 in which the proportion of those both over 65 years and under 15 years will be rather low. The dependency ratio should begin to climb after 2020, reaching a peak in 2040 and stabilizing by 2070 at a level slightly higher than that existing today in developed countries. Since a rational age composition and a suitable decrease in the proportion of dependents are essential for economic growth, future analyses should focus on the quality of the population and not just population size. As long as birth rates continue to fall, the proportion of the dependent population will also fall and have a beneficial effect on China's economic development.