Approximation strategy-proof mechanisms for obnoxious facility location on a line

In the facility location game on a line, there are some agents who have fixed locations on the line where an obnoxious facility will be placed. The objective is to maximize the social welfare, e.g., the sum of distances from the facility to all agents. On collecting location information, agents may misreport the locations so as to stay far away from the obnoxious facility. In this paper, strategy-proof mechanisms are designed and the approximation ratio is used to measure the performances of the strategy-proof mechanisms. Two objective functions, maximizing the sum of squares of distances (maxSOS) and maximizing the sum of distances (maxSum), have been considered. For maxSOS, a randomized 5/3-approximated strategy-proof mechanism is proposed, and the lower bound of the approximation ratio is proved to be at least 1.042. For maxSum, the lower bound of the approximation ratio of the randomized strategy-proof mechanism is proved to be 1.077. Moreover, a general model is considered that each agent may have multiple locations on the line. For the objective functions maxSum and maxSOS, both deterministic and randomized strategy-proof mechanisms are investigated, and the deterministic mechanisms are shown to be best possible.     

高校物业管理改革趋势分析

提高教育投资效益,已成为决定一个高校展的关键要素.改革高校物业管理已势在必行,改革的总趋势是物业管理服务化;服务方式商品化;商品服务市场化;市场服务竞争化;竞争服务效益化;效益服务优质化.改革的过程是渐变,而非突变.     

The influence of acculturation level and family relationships on quality of life among U.S. Chinese older adults

ABSTRACT

The present study examined the influence of acculturation level and family relationships (i.e., positive family support and negative family strain) on quality of life (QOL), using the data from the Population Study of ChINese Elderly (PINE) in Chicago (N = 3159). Controlling for sociodemographic variables and health status, it was found that individuals’ acculturation level and positive family support were positively related to QOL, whereas negative family strain was negatively associated with QOL. More importantly, higher acculturation levels were associated with increased protective effects of positive family support and reduced risk effects of negative family strain on QOL among U.S. Chinese older adults.     

新型城镇化发展质量提升创新驱动因素的实证分析

文章构建“创新驱动”视角下的新型城镇化发展质量评价指标体系,并测算出2000-2015年江、浙、沪的新型城镇化发展质量状况.依据三个地区“创新驱动”视角下的新型城镇化发展质量和影响因素的面板数据构建了随机效应变截矩模型,研究发现人力资本、技术创新、机构创新和制度创新等创新驱动因素对江、浙、沪新型城镇化发展质量提升起到重要的推动作用.     

Computing A-optimal and E-optimal designs for regression models via semidefinite programming

In semidefinite programming (SDP), we minimize a linear objective function subject to a linear matrix being positive semidefinite. A powerful program, SeDuMi, has been developed in MATLAB to solve SDP problems. In this article, we show in detail how to formulate A-optimal and E-optimal design problems as SDP problems and solve them by SeDuMi. This technique can be used to construct approximate A-optimal and E-optimal designs for all linear and nonlinear regression models with discrete design spaces. In addition, the results on discrete design spaces provide useful guidance for finding optimal designs on any continuous design space, and a convergence result is derived. Moreover, restrictions in the designs can be easily incorporated in the SDP problems and solved by SeDuMi. Several representative examples and one MATLAB program are given.     

A narrative inquiry into the identity formation of Chinese doctoral students in relation to study abroad

The present study explores a topic which has been under-studied to date, namely the identity formation of Chinese PhD students in relation to study abroad. Underpinned by Giddens’ ‘reflexive project of the self’, which privileges agency and reflexivity, and using a narrative inquiry approach, it presents four students ‘stories’ collected through semi-structured interviews and focus group discussions. In building a picture of the ways in which students’ self-identity is shaped by and shapes their experience of study abroad, the stories illustrate individual agency, motivation, self-determination and reflexivity. In doing so, they challenge the essentialised view of Chinese students as a homogeneous and sometimes problematic group and point to implications for action by the host institutions.     

从2013年度性别事件看性别平等

随着2013“年度十大性别平等新闻事件”以及“年度十大性与性别事件”的发布,让我们回顾2013年发生的具有典型性和代表性的性别新闻事件和现象,共同探讨有哪些关于女性权益的保护应该引起全社会关注。     

劳动参与率与劳动力增长:1982～2050年

劳动参与率是影响劳动力变化的三要素之一。它一方面具备相对稳定的模式,另一方面又受到一系列个人和外部因素的影响。文章基于普查数据,着重分析了劳动参与的年龄模式和主要影响因素,并预测了未来劳动力的发展趋势。结果发现,中国劳动参与年龄模式正趋向于稳定的倒U形,存在着明显的性别、城乡差异。回归结果表明,高中以上受教育程度可大大提高劳动参与,特别是女性的劳动参与,表明人力资本是未来劳动力发展的一个根本因素。预测结果显示,劳动力规模10年后将不可避免地出现负增长,同时中老年劳动力的比重也会大幅上升。对此,应采取相应措施以减轻劳动力变化所带来的震荡。     

后现代视阈中大学生非主流现象

作为一种社会现象和社会存在,非主流文化深刻影响了大学生尤其是90后大学生日常生活的方方面面。非主流大学生在话语特征、思想观念和行为方式方面有独特的符号系统;非主流文化反映了后现代个体强烈的从众心理、逆反心理、娱乐心理、抗争心理和渴望展现自我的心理;非主流现象的盛行启示青年研究工作应转变范式,青年教育工作应更新理念,文化建设应兼容并蓄;对待非主流现象,应顺其自然,让时间和历史来检验非主流文化存在的价值与意义。     

“90后”大学生信息获取渠道与价值观的形成研究

"90后"大学生、出生成长在信息时代,信息获取渠道的多元化对他们的价值观形成造成较大的影响。其中,值得关注的影响有:信息焦虑与价值认同的矛盾、道德价值观体现传承特性、政治热情与冷漠并存、人生价值的媒介之"伤"等。因此,要净化媒介环境,提高"90后"大学生媒介素养,实现价值观教育的功能一致性,以强化主导价值观的引导作用。