库存共享和服务水平限制下三级分销网络侧向转运模型与算法

侧向转运是库存共享的一种方式,一方面会减少库存成本,另一方面又会因转运而增加运输成本,针对这一问题考虑不同时间窗W^k的服务水平产生的服务水平的分级,构建三级分销网络中基于库存共享与时间服务水平限制的批量订货模型,分销网络模型中包含一个制造商、一个RDC、m个DC、n个客户。其中客户的需求相互独立且服从泊松分布,DC的订货提前期服从指数分布。首先,建立了基于时间服务水平限制的分销网络系统总成本最小化模型,并将再购点、订购批量等库存参数作为同时作为决策变量,以达到三级备件分销网络的成本优化;其次,根据问题和模型的特点对所建的模型开发了基于采用贪婪增加算法的求解思想求解问题,以便给管理者提供决策参考并通过降低利润的方式增加效益和资源利用率;最后,通过中航材集团推行的“航材共享”项目作为算例分析,将三个分销区域与机场群组成的备件分销系统进行建模分析,验证了本文模型的有效性,成本优化的显著性。研究结果表明,三级分销网络中,RDC采用连续盘点的（Q,R）补货策略、DC采用（Q,R,H）的补货策略时系统总成本与普遍采用的定期盘点策略和连续盘点中的One-for-One订货策略成本相比,DC之间的库存共享策略能有效降低整个系统的成本,例如,在案例研究中发现成本降低约为30%。     

Dose‐Response Model of Coxiella burnetii (Q Fever)

Q fever is a zoonotic disease caused by the intracellular gram‐negative bacterium Coxiella burnetii (C. burnetii), which only multiplies within the phagolysosomal vacuoles. Q fever may manifest as acute or chronic disease. The acute form is generally not fatal and manifestes as self‐controlled febrile illness. Chronic Q fever is usually characterized by endocarditis. Many animal models, including humans, have been studied for Q fever infection through various exposure routes. The studies considered different endpoints including death for animal models and clinical signs for human infection. In this article, animal experimental data available in the open literature were fit to suitable dose‐response models using maximum likelihood estimation. Research results for tests of severe combined immunodeficient mice inoculated intraperitoneally (i.p.) with C. burnetii were best estimated with the Beta‐Poisson dose‐response model. Similar inoculation (i.p.) trial outcomes conducted on C57BL/6J mice were best fit by an exponential model, whereas those tests run on C57BL/10ScN mice were optimally represented by a Beta‐Poisson dose‐response model.     

无名身份的解构叙事——《阿Q正传》叙事艺术解读

后现代叙事理论告诉我们叙事就是身份的制造,但对于制造一个无名身份的叙事,其本身就是反叙事的。鲁迅在《阿Q正传》里借助对阿Q的塑造为读者展示了这种无名身份的独特叙事过程:那就是作者在解构中还原,而读者被迫在还原中解构。这种叙事模式包含着深层的哲理意味,既是对叙事的挑战,也造就了叙事的伦理效应。     

多元广义压缩最小二乘估计

引进了多元线性模型中回归系数β＝Ｖｅｃ（Ｂ）的广义压缩最小二乘估计β（Ａ），讨论了它的约方误差与均方残差的性质，指出了根据均方误差准则选取Ａ值的主要缺陷，采用了一种选取Ａ值的新准则Ｑ（ｃ），它包含均方误差准则和最小二乘准则作为特例，并从理论上证明了Ｑ（ｃ）准则的优良性．     

A Remark on the Zhang Omnibus Test for Normality

Zhang (1999) proposed a novel test statistic Q for testing normality based on the ratio of two unbiased standard deviation estimators, q₁ and q₂, for the true population standard deviation σ. Mingoti & Neves (2003) discussed some properties of q₁ and q₂ and showed that the variance of q₁ increases as the true population variance increases. In this paper, we show that the distribution of q₁ is not normal. As a result, normality percentage points for Q are not appropriate. In this paper, percentage points of Q are obtained using simulations. Monte Carlo simulations are provided to evaluate the performance of the new method and Zhang's method.     

“3Q大战”所引发的相关法律问题分析与思考

2010年10月发生了中国互联网发展历史上的“3Q大战”（腾讯与360之争）。本文首先在对“3Q大战”回顾的基础上,从大战当事双方的角度提出问题;然后从法律法规、监管等角度,对“3Q大战”引发的相关法律、监管等方面的问题进行深入分析;最后提出相关建议。     

Women and men as conservers, users and managers of agrobiodiversity: A feminist social–ecological approach

This feminist socio-ecological heuristic studies agrobiodiversity management, conservation and utilisation by men and women. Four approaches are characterised for an analysis of institutions, local knowledge, household economics and commodity chains. They are in turn linked to unveil their potential contributions towards a better understanding women's handling of, interests in and dependence on agrobiodiversity. The conceptualisation of a feminist framework aims at better informed research into the relationships between women, men and plants and is illustrated by examples from South Asia. Insights derived from a feminist socio-ecological perspective on agricultural biodiversity serve to generate gender-relevant policy recommendations towards establishing sustainable farming systems.     

Wage inequality and team production: An experimental analysis

Numerous survey studies report that human resource managers curb wage inequality with the intent to avoid detrimental effects on workers’ morale. However, there exists little controlled empirical evidence demonstrating that horizontal social comparisons and wage inequality have adverse effects on worker behavior. In this paper, we present data from a laboratory experiment that studies the impact of wage inequality on participation and effort choices in team production. Overall, we do not find evidence that wage inequality has a significant impact on either participation or effort choices.     

Impact of Value‐Added Service Features in e‐Retailing Processes: An Econometric Analysis of Web Site Functions

We examine the impact of three classes of Web site functions (foundational, customer‐centered, and value‐added) upon e‐retailer performance. Using secondary panel data for 2007–2009 on operating characteristics of over 600 e‐retailers, our econometric analysis finds that only the value‐added service functions are positively associated with changes in e‐retail sales revenues across time. We also observe a decreasing marginal impact of deploying additional value‐added service features. To account for possible alternate explanations, we control for firm‐ and time‐specific fixed effects, merchant types, merchandise categories, and order fulfillment strategies. By further decomposing e‐retail sales revenues into Web site traffic, conversion rate, and average order value, we find that Web site functions affect e‐retail sales revenues mainly through their impact on Web site traffic. Our investigation demonstrates the empirical research usefulness of the Voss conceptual e‐service sand cone model. Our results identify for managers where to focus ongoing e‐retailing system development efforts, yet suggest that focusing too many retailing capabilities on exploratory and experimental value‐added service features may backfire, potentially leading to worsening e‐retailer performance.     

Pollutant emissions,energy use and real output in Sub-Saharan Africa (SSA) countries

Industrialisation is pivotal to growth sustainability and this requires intense energy use that may invariably trigger pollutant emissions thereby necessitating some evidence-based policy concerns. This study therefore examines the dynamic connection among pollutant emission, energy use and real output per capita in SSA. Owing to cross-sectional dependence, the Prais-Winsten model with panel-corrected standard error (PCSE) alongside the panel spatial correlation consistent (PSCC) approach is applied and key findings are established. First, the EKC hypothesis holds and this is striking for both oil-rich and oil-poor SSA countries. Second, energy use induces pollutant emissions in oil-rich SSA countries but not in oil-poor SSA countries. Third, pollutant emissions and energy use are real output per capita-enhancing in SSA generally and in oil-poor countries. Thus, policy measures to safeguard efficient optimisation of energy use in ensuring a balance as well as developing SSA’s rich renewable energy sources is imperative for long-run growth.