On sequential closed testing dose groups with a control

Methods for a sequential test of a dose-response effect in pre-clinical studies are investigated. The objective of the test procedure is to compare several dose groups with a zero-dose control. The sequential testing is conducted within a closed family of one-sided tests. The procedures investigated are based on a monotonicity assumption. These closed procedures strongly control the familywise error rate while providing information about the shape of the dose-responce relationship. Performance of sequential testing procedures are compared via a Monte Carlo simulation study. We illustrae the procedures by application to a real data set.     

新经济地理学视域下的中印边境经贸研究

新经济地理学视域下,边境不再是人为阻隔生产要素流动的非贸易壁垒,而是促进国际专业化分工和形成循环因果积累效应的天然地理因素。基于新经济地理学的相关理论,研究中印边境贸易的专业化模式和贸易模式以及边境贸易政策对中印边境贸易的影响,以论证中印两国经贸的比较优势在边境地区的空间整合,最终推动中印边境贸易健康发展。     

Variable Selection via Regression Trees in the Presence of Irrelevant Variables

Many tree algorithms have been developed for regression problems. Although they are regarded as good algorithms, most of them suffer from loss of prediction accuracy when there are many irrelevant variables and the number of predictors exceeds the number of observations. We propose the multistep regression tree with adaptive variable selection to handle this problem. The variable selection step and the fitting step comprise the multistep method.

The multistep generalized unbiased interaction detection and estimation (GUIDE) with adaptive forward selection (fg) algorithm, as a variable selection tool, performs better than some of the well-known variable selection algorithms such as efficacy adaptive regression tube hunting (EARTH), FSR (false selection rate), LSCV (least squares cross-validation), and LASSO (least absolute shrinkage and selection operator) for the regression problem. The results based on simulation study show that fg outperforms other algorithms in terms of selection result and computation time. It generally selects the important variables correctly with relatively few irrelevant variables, which gives good prediction accuracy with less computation time.     

“微信热”背后高校思想政治教育的冷思考

大学生是微信最忠实的拥趸,“微信热”不仅给大学生的工作和生活带来了诸多影响,同时也给高校思想政治教育工作带来了严峻挑战。微信的不可控性,使高校思想政治教育环境趋于复杂;微信立体化的社交形式,使高校思想政治教育方法受到挑战;微信的虚拟性,使高校思想政治教育过程难度加大;微信信息的“碎片化”,削弱了高校思想政治教育实效性。在“微信热”背景下,探讨其产生的深层原因,科学应对微信带来的挑战,运用微信进行“微创新”、发挥“微功能”,对大学生思想政治教育意义重大。     

Measuring Social Tension from Income Class Segregation

We develop an index that effectively measures the level of social tension generated by income class segregation. We adopt the basic concepts of between-group difference (or alienation) and within-group similarity (or identification) from the income [bi]polarization literature; but we allow for asymmetric degrees of between-group antagonism in the alienation function, and construct a more effective identification function using both the relative degree of within-group clustering and the group size. To facilitate statistical inference, we derive the asymptotic distribution of the proposed measure using results from U-statistics. As the new measure is general enough to include existing income polarization indices as well as the Gini index as special cases, the asymptotic result can be readily applied to these popular indices. Evidence from the Panel Study of Income Dynamics data suggests that, while the level of social tension shows an upward trend over the sample period of 1981 to 2005, government’s taxes and transfers have been effective in reducing the level of social tension significantly.     

大型航空制造企业技术改造项目管理新模式

技术改造及其项目管理是大型航空制造企业经营管理活动中的重要任务之一。企业通过技术 改造项目改进生产条件和生产工艺,增强军民用航空产品的研制能力。论文根据技改项目管 理的特点,运用系统动力学方法建立技改项目全生命周期动力学模型,对技改项目生命周期 的全过程进行动态仿真,为管理者提供信息和决策支持。最后,结合工作流技术的优点,建 立了基于工作流技术的技改项目管理协同平台原型     

文官政治·书卷风流·人文气象--宋代文学存在的社会文化背景分析

有宋一代 ,文化大昌 ,文学也出现繁荣气象 ,这同宋代的社会环境及文化背景密切相关。宋型文化 ,有着向内收敛及注重人文涵养的倾向 ,这也深深影响了宋代文学及文学思想。简言之 ,宋代社会的基础是文官政治 ,内在精神是注重品性涵养 ,外在的表现是书卷风流。它们三位一体 ,构成了宋人所处的富于浓郁人文气息的氛围 ,其审美情趣也从外在的羁旅漫游、征戍迁谪、行旅离别 ,逐渐转向丰富多彩的心智活动 ,于是构成宋代文学及文学思想中博大精深的人文气象     

竞争中的参考价格效应及承诺

消费者的社会感知会影响其对产品和品牌的评价。当消费者进行购买选择时,经常会受到参考价格效应的影响。而广告和价格不仅是企业经常要考虑的重要决策,还会对参考价格产生重要影响。为此,一个值得研究的的问题是：在考虑参考价格效应的情况下,企业该怎样确定其动态广告和价格策略？
为了研究该问题,本文构建了一个广告和价格的动态模型,来研究一个双寡头市场环境下两个寡头企业的价格和广告决策,并以此分析参考价格效应的作用。具体而言,我们假定企业可以采用广告承诺和价格承诺中的一种,其中前者承诺其在一段时间内的广告投入量恒定不变,而后者确保价格不变。两种策略不仅会影响消费者的购买决策,也会影响竞争对手的选择。在上述假定下,我们探讨了两个寡头企业在都采用广告承诺、都采用价格承诺及一个企业采用广告承诺而另一个企业采用价格承诺等三种不同情形下的最优广告和价格决策,并以此分析了三种情形下参考价格效应对最优的广告投入及定价策略的影响。最后,通过数值分析,探讨了不同情形下企业的最优策略选择。