Modifications of sequential designs in bioequivalence trials

Bioequivalence (BE) studies are designed to show that two formulations of one drug are equivalent and they play an important role in drug development. When in a design stage, it is possible that there is a high degree of uncertainty on variability of the formulations and the actual performance of the test versus reference formulation. Therefore, an interim look may be desirable to stop the study if there is no chance of claiming BE at the end (futility), or claim BE if evidence is sufficient (efficacy), or adjust the sample size. Sequential design approaches specially for BE studies have been proposed previously in publications. We applied modification to the existing methods focusing on simplified multiplicity adjustment and futility stopping. We name our method modified sequential design for BE studies (MSDBE). Simulation results demonstrate comparable performance between MSDBE and the original published methods while MSDBE offers more transparency and better applicability. The R package MSDBE is available at https://sites.google.com/site/modsdbe/ . Copyright © 2015 John Wiley & Sons, Ltd.     

不同冷链服务模式下生鲜农产品供应链决策

基于单物流服务商、单供应商和单零售商构成的生鲜农产品供应链，构建3种冷链服务模式：承诺模式、提前要求模式与延后要求模式，探讨不同冷链服务模式对定价与冷链服务水平、企业绩效的影响。研究发现：某种冷链服务模式是否有利于消减数量与质量损耗依赖于产品易腐性、冷链服务成本及其分担比例。供应链成员无法在承诺模式与提前要求模式下形成统一的模式偏好。当物流服务商承担的冷链服务成本比例较低时，相比于提前要求模式，供应商偏好承诺模式，否则，偏好提前要求模式。承诺模式比提前要求模式更有利于物流服务商，然而对于零售商，结果正好相反。数值实验表明，虽然供应链成员无法对冷链服务模式形成整体的一致性偏好，但仍可实现局部的一致性偏好。     

网络多元文化对自我同一性的影响

自我同一性是个体在发展阶段中对自我的一种感知、确认和整合，网络多元文化对个体的自我同一性既具有积极的影响作用，也可能会带来一定的负面效应，因此应在一种新的自我观的基础上积极寻求应对策略。     

Constrained vs unconstrained labor supply: the economics of dual job holding

This paper develops a unified model of dual and unitary job holding based on a Stone-Geary utility function. The model incorporates both constrained and unconstrained labor supply. Panel data methods are adapted to accommodate unobserved heterogeneity and multinomial selection into six mutually exclusive labor supply regimes. We estimate the wage and income elasticities arising from selection and unobserved heterogeneity as well as from the Stone-Geary Slutsky equations. The labor supply model is estimated with data from the British Household Panel Survey 1991–2008. Among dual job holders, our study finds that the Stone-Geary income and wage elasticities are much larger for labor supply to the second job compared with the main job. When the effects of selection and unobserved heterogeneity are taken account of, the magnitudes of these elasticities on the second job tend to be significantly reduced.     

The intergenerational education spillovers of pension reform in China

Economic theory establishes that pension privatization weakens the link between old and young and so reduces the incentive to invest in public education in an economy with lower return rate of capital than growth rate of wage. However, empirical studies of the link change are few. In this paper, we investigate the effects of pension privatization and the central government’s subsidy to individual accounts on public education spending in a three-period overlapping generation model. And then, we take contemporary pension reforms in a number of Chinese provinces as offering natural experiment conditions. Using a difference-in-difference framework and 282 municipal districts panel data over years 1998–2009, we test the pension-education theoretical link change. Both our theoretical and empirical results confirm that pension privatization is adversely associated with local public spending on education in China. Private pension subsidies, moreover, magnify this effect. Our study supports the theoretical assertion and selective empirical findings of a negative intergenerational effect of pension privatization.     

政府减排目标、产业结构与污染减排

政府是污染减排的重要主体,了解其行为对污染减排的作用对提升污染减排效果及实现中国绿色发展具有重要意义。创造性地将政府减排目标纳入研究框架,构建面板门槛模型,从工业污染排放总量的角度分析政府减排目标、产业结构、经济规模等因素对地方污染减排的影响,并用工业污染物强度进行稳健性检验。结果显示,政府减排目标对污染减排的作用存在阶段性不同:经济发展初级阶段,政府减排目标对污染排放总量的作用方向为正; 经济发展水平较高时,作用方向为负; 两者之间存在适应性调整阶段,作用方向具有不确定性,但总体由正向作用向负向作用转变。产业结构对工业污染排放总量的作用方向因污染物种类而异,经济规模对工业污染排放总量作用方向为正。     

冷战后的中美政治安全关系

冷战结束十年以来 ,美国的对华政策依然摇摆不定。之所以如此 ,是因为十年来美国视中国为敌还是为友 ,或者非敌非友 ,至今还未定性。而美国难于在其国际政治安全战略中给中国定性的原因 ,则与以下的三个层次密切相关 ,即美国的国内政治层次、中美关系的发展层次和全球层次。     

金诗学唐的历程

金代诗歌在受苏轼等宋代诗人的影响之外 ,也受到唐诗的浸润。本文依据金诗发展变化的自身情况 ,考察了金诗学唐的历程。文中将金诗学唐分为金初“借才异代”时期、“国朝文派”时期、金代后期等三个阶段 ,做了比较详细的论述 ,从一个方面展示了金诗发展的轨迹 ,揭示了金诗的某些重要特点 ,对于我们深入地认识金诗是有裨益的     

关于体育教育专业学生能力培养的研究

通过查阅文献资料和问卷调查反馈,研究分析发现,当前体育教育专业学生能力还不能适应社会发展的需要,且发展不平衡。我们认为,对体育教育专业学生能力的培养应从师德教育、教学表达能力、教学组织能力、教学设计能力、适应教学环境的能力、体育教学自修与改革能力、社会竞争能力等方面下手,使学生的能力在四学年的教学实践活动中,得到有序全面的锻炼和提高、达到最佳培养效果。为他们将来成为合格的、高素质的复合型人才打下坚实的基础。     

A majorization comparison of apportionment methods in proportional representation

From the inception of the proportional representation movement it has been an issue whether larger parties are favored at the expense of smaller parties in one apportionment of seats as compared to another apportionment. A number of methods have been proposed and are used in countries with a proportional representation system. These apportionment methods exhibit a regularity of order, as discussed in the present paper, that captures the preferential treatment of larger versus smaller parties. This order, namely majorization, permits the comparison of seat allocations in two apportionments. For divisor methods, we show that one method is majorized by another method if and only if their signpost ratios are increasing. This criterion is satisfied for the divisor methods with power-mean rounding, and for the divisor methods with stationary rounding. Majorization places the five traditional apportionment methods in the order as they are known to favor larger parties over smaller parties: Adams, Dean, Hill, Webster, and Jefferson. Received: 5 August 2000/Accepted: 24 October 2001