考虑鉴真服务和消费者偏好的混合E-供应链决策研究

鉴真服务平台通过提供鉴真服务,为线上商品的出售提供了质量保障,切实提高了消费满意度,降低了线上产品退货率。对此,本文构建了由鉴真服务E-供应链和传统E-供应链组成的混合E-供应链系统;运用Stackelberg博弈,求解集中式和分散式决策下的最优定价策略及利润;分析鉴真努力程度对各模型运作的影响,并对不同模型的最优决策进行比较;最后通过数值分析,对模型结论进行验证。研究表明：1)无论是集中式决策还是分散式决策,两个渠道的产品销售价格均随鉴真努力程度的增大而增加,而混合E-供应链总利润随鉴真努力程度的增大先减小后增大;2)分散式决策模式中,鉴真渠道的产品销售价格在销售商主导模型下更高,而销售商总利润和鉴真平台利润在鉴真平台主导模型下更高,且鉴真平台所获取的佣金及鉴真平台的利润均随鉴真努力程度的增大而增加,销售商总利润随鉴真努力程度的增加先减小后增大;3)集中式决策模式中混合E-供应链的总利润最高,且此时主要利润为销售商所得。本文的研究进一步丰富和发展了混合E-供应链决策理论,而且为鉴真服务平台和线上销售商的经营决策提供参考。     

Diesel Engine Exhaust and Lung Cancer Mortality: Time‐Related Factors in Exposure and Risk

To develop a quantitative exposure‐response relationship between concentrations and durations of inhaled diesel engine exhaust (DEE) and increases in lung cancer risks, we examined the role of temporal factors in modifying the estimated effects of exposure to DEE on lung cancer mortality and characterized risk by mine type in the Diesel Exhaust in Miners Study (DEMS) cohort, which followed 12,315 workers through December 1997. We analyzed the data using parametric functions based on concepts of multistage carcinogenesis to directly estimate the hazard functions associated with estimated exposure to a surrogate marker of DEE, respirable elemental carbon (REC). The REC‐associated risk of lung cancer mortality in DEMS is driven by increased risk in only one of four mine types (limestone), with statistically significant heterogeneity by mine type and no significant exposure‐response relationship after removal of the limestone mine workers. Temporal factors, such as duration of exposure, play an important role in determining the risk of lung cancer mortality following exposure to REC, and the relative risk declines after exposure to REC stops. There is evidence of effect modification of risk by attained age. The modifying impact of temporal factors and effect modification by age should be addressed in any quantitative risk assessment (QRA) of DEE. Until there is a better understanding of why the risk appears to be confined to a single mine type, data from DEMS cannot reliably be used for QRA.     

高校本科毕业设计（论文）质量的几点思考

在探讨毕业设计（论文）对本科实践教学所具有的重要性的基础之上,分析了近年来影响毕业设计（论文）质量的一些基本因素,针对这些因素,结合本校相关措施,就创新人才培养模式下如何提高毕业设计（论文）的质量进行了探讨。     

李清照"憔悴"词作年新测——以《永遇乐·元宵》为考察中心

本文对李清照<金石录后序>的"屏居乡里十年"首次作出确切的界定:1107--1116年(闰正月之前).<永遇乐>的"元宵"即1129年的元宵;该词中的"重(chóng)三五"即1116年的闰元宵.又利用李清照词、文、诗中的内证,提出李清照自比洞庭龙女的新说;再根据李清照习惯于自道"憔悴"的特点,论证<声声慢>(寻寻觅觅)、<临江仙>(庭院深深深几许)、<玉楼春>(红酥肯放琼包碎)、<永遇乐·元宵>四首"憔悴词"皆作于明诚逝世之前,特别论证了后三词作于1129年的金陵;文中还对宋人周煇、张端义、刘辰翁的记载或看法提出了质疑.     

陕西民间乐舞中的"傩"

为探索"傩"文化的潜在价值,通过文献分析和实地考察等方法,认为傩文化是先民遗存的活态文化基因,其包含着人类自身丰富的潜性思维方式及原始宗教与乐舞艺术.因此,它对中外文化艺术交流,对三秦大众的精神生活和文化娱乐生活将产生重大的影响.     

Two-Event Model for Carcinogenesis: Biological, Mathematical, and Statistical Considerations

A two-mutation model for carcinogenesis is reviewed. General principles in fitting the model to epidemiologic and experimental data are discussed, and some examples are given. A general solution to the model with time-dependent parameters is developed, and its use is illustrated by application to data from an experiment in which rats exposed to radon developed lung tumors.     

在读女研究生怀孕问题的分析与思考——以“理性选择理论”为视角

本文在对141份样本统计分析的基础上，揭示了在读女研究生怀孕的动因及在校研究生对此类事情的不同认识与态度，并进一步从理性选择理论的视角出发表达了笔者对此问题的思考与看法。     

Either with us or against us: experimental evidence on partial cartels

This paper analyzes the coordination challenge a partial cartel faces when payoff asymmetries between potential cartel insiders and potential cartel outsiders are large. We introduce two experimental treatments: a standard treatment where a complete cartel can be supported in a Nash equilibrium and a modified treatment where a complete cartel and a partial cartel can both be supported in a Nash equilibrium. To assess the role of communication both treatments are additionally run with a “chat option,” yielding four treatments in total. Our results show that subjects frequently reject the formation of partial cartels in the modified treatments. In all treatments with communication subjects are more likely to form complete cartels than partial cartels. The implications of these results are important for antitrust: payoff asymmetries between cartel members and outsiders may jeopardize the formation of partial cartels. Yet complete cartels may be formed instead, if institutional mechanisms with frequent communication are used to form cartels.

     

On diagnostic checking of the autoregressive conditional intensity model

The autoregressive conditional intensity model proposed by Russell (1998) is a promising option for fitting multivariate high frequency irregularly spaced data. The authors acknowledge the validity of this model by showing the independence of its generalized residuals, a crucial assumption of the model formulation not readily recognized by researchers. The authors derive the large‐sample distribution of the autocorrelations of the generalized residual series and use it to construct a goodness‐of‐fit test for the model. Empirical results compare the performance of their test with other off‐the‐shelf tests such as the Ljung–Box test. They illustrate the use of their test with transaction records of the HSBC stock.     

Testing lack of symmetry in spatial–temporal processes

Symmetry and separability of a covariance function are common assumptions to simplify the modeling effort of spatial–temporal processes. However, many studies in environmental sciences show that real data have complex spatial–temporal dependency structures resulting from lack of symmetry or violation of other standard assumptions of the covariance function. In this study, we propose new formal tests for lack of symmetry by using spectral representations of the spatial–temporal covariance functions of regularly spaced spatial–temporal data. The advantage of the proposed tests is that classical analysis of variance (ANOVA) models can be used for detecting lack of symmetry inherent in spatial–temporal processes. We evaluate the performance of the tests with simulation studies and we apply them to air pollution data.