Proportional hazards model for competing risks data with missing cause of failure

We consider the semiparametric proportional hazards model for the cause-specific hazard function in analysis of competing risks data with missing cause of failure. The inverse probability weighted equation and augmented inverse probability weighted equation are proposed for estimating the regression parameters in the model, and their theoretical properties are established for inference. Simulation studies demonstrate that the augmented inverse probability weighted estimator is doubly robust and the proposed method is appropriate for practical use. The simulations also compare the proposed estimators with the multiple imputation estimator of Lu and Tsiatis (2001). The application of the proposed method is illustrated using data from a bone marrow transplant study.     

多维背包问题的二进制蚂蚁算法

针对著名的多维背包问题(MKP), 在蚁群优化系统高维立方体结构的基础上,提出了一种二进制蚂蚁算法(BAS).与其他求解MKP问题的蚂蚁算法不同,BAS根据二进制解的结构设计了特殊的信息素放置方式,同时在算法的迭代过程中允许非可行解的产生,并通过基于问题特征信息的修改算子修复每次迭代所产生的非可行解.BAS算法采用了特殊的信息素更新规则,使得各个选择路径上的信息素可以直接作为选择概率,同时,为了避免算法陷入早熟,BAS设计了简单的局部搜索法,并根据算法所处的不同收敛状况,采用了不同的信息素更新规划和信息素重新初始化的方法.针对MKP基准问题的实验结果表明,BAS具有超越其他蚂蚁算法的求解结果,其求解不同基准测试问题的能力表明了BAS具有解决超大规模MKP问题的潜力.     

上市公司治理:理论与现实的距离——基于1250份上市公司“自查报告和整改计划”的分析

本文根据1250家上市公司所公布的"自查报告和整改计划",重点从大股东、董事会/监事会、经理层以及投资者法律保护等四个方面对"自查报告和整改计划"的调查问题进行全面归纳、整理、分解和剖析,通过统计分析和理论文献对比,综合反映出目前我国上市公司治理现状和问题.调查分析结果表明,虽然我国目前已基本上建立了一整套与上市公司治理相关的法律法规,上市公司在大股东、董事会、经理层和投资者保护等方面的行为得到了一定的规范约束.但是,我国上市公司治理仍然处在不断完善过程中,如何强化大股东的信托义务和法律责任,从根本上解决大股东侵占中小股东利益的问题、保证董事会制度的独立性和有效性、培育经理人市场,积极推进股权激励机制、落实投资者法律保护制度等成为今后完善我国上市公司治理的重要任务.     

Pathways to happiness: From personality to social networks and perceived support

The present study attempts to incorporate individual personality into a social network account of subjective wellbeing (SWB) by proposing and testing a path model in which social relationships (egocentric social networks and perceived social support, PSS) mediate the relationship between personality and SWB. We found that network characteristics (including network size, emotional closeness, and proportion of new contacts) are related to SWB largely via the mediation of PSS. Additionally, network size and proportion of new contacts function as important mediating mechanisms linking extraversion, agreeableness and openness to PSS and SWB.     

Assessing Overweight,Obesity, Diet,and Physical Activity in College Students

Abstract

The authors surveyed 738 college students aged 18 to 27 years to assess overweight, obesity, dietary habits, and physical activity. They used BMI (body mass index) > 25 kg/m² or BMI > 85th percentile and BMI > 30 kg/m¹ or BMI > 95th percentile to estimate overweight and obesity in those aged < 19 years. To define overweight and obesity in those > 20 years, they used BMI > 25 kg/m² and > 30 kg/m². They found overweight rates of 21.6% using BMI directly and 16.2% using BMI percentile and obesity rates of 4.9% using BMI directly and 4.2% using BMI percentile. More than 69% of the participants reported < 5 servings of fruits and vegetables per day and more than 67% reported < 20 g of fiber per day; participants reported physical activity on fewer than 3 d/wk. Most college students are not meeting dietary and physical activity guidelines, suggesting the need for prevention interventions and increased understanding of overweight in college students.     

Exploring Definitions of Financial Abuse in Elderly Korean Immigrants: The Contribution of Traditional Cultural Values

The purpose of this study is to explore the cultural definitions of financial abuse from the perspective of 124 elderly Korean immigrants and to examine the role of traditional cultural values in their definitions by using a mixed methods approach. The qualitative analysis generated four themes relevant to definition of financial abuse. A binary logistic regression indicated that those with stronger cultural adherence to traditional values had higher odds of providing culture-based definitions of financial abuse. Education is needed for health professionals, social service providers, and adult protective workers to increase their understanding of culture-specific experiences of financial abuse among ethnic minority elders.     

伊玛堪生成发展的文化基础及其历史价值

伊玛堪以东北地区高纬度、寒温带大陆性季风气候的三江流域为地理环境基础,以渔猎为物质文化基础,以萨满教为精神文化基础,以相邻民族文化涵化为多元文化基础而产生并代代相传;作为赫哲族独有的一种口耳相授的古老文学样式,在历史学、民族学、民俗学、哲学、宗教学、美学、语言学、文学等诸多领域中展现出丰富的文化内涵,是赫哲族传统文化的“活化石”,为赫哲族历史文化研究提供了大量的佐证资料,具有极其珍贵的历史文化价值.     

农民维权理性的法理学思考

当代农民维权行动具有强烈的工具理性特征。以工具理性为主导的农民维权行动虽能在特定个案中发挥作用,但其隐含的压制性逻辑却会对社会和谐产生负面影响,难以产生普适性的问题解决规则,难以摆脱工具理性自我否定的内在困境。交往理性是超越工具理性,并使农民维权行动获得理性化发展的基础。