一类考虑反 S型概率权重的供货中断库存模型

在连续盘点库存系统中应用零点订货库存（ZIO）策略,假设供应商工作和中断的持续时间分别服从独立的指数分布。首先,引入反S 型权重函数刻画风险厌恶型决策者主观高估补货点供应商处于中断的小概率关键事件的行为偏好。其次,利用两个状态连续时间Markov 链和更新报酬定理构建了长程平均成本模型,证明了成本函数的单峰性,对比讨论了结合数值算例与风险中性模型结论。最后,设计了近似条件得出最优订货量的解析表达式及成本的近似误差上界,配合基准集和随机数据集分别计算了160 组和 10 000 组数值实验样本,验证了近似方法的有效性。     

Distributed Decision‐Making in Supply Chains and Private E‐Marketplaces

This paper develops a distributed decision‐making framework for the players in a supply chain or a private e‐marketplace to collaboratively arrive at a global Pareto‐optimal solution. In this model, no player has complete knowledge about all the costs and constraints of the other players. The decision‐making framework employs an iterative procedure, based on the Integer L‐shaped method, in which a master problem is solved to propose global solutions, and each player uses his local problems to construct feasibility and optimality cuts on the master problem. The master problem is modeled as a mixed‐integer program, and the players' local problems are formulated as linear programs. Collaborative planning scenarios in private e‐marketplaces and in supply chains were formulated and solved for test data. The results show that this distributed model is able to achieve near‐optimal solutions considerably faster than the traditional centralized approach.     

Modeling U‐Shaped Exposure‐Response Relationships for Agents that Demonstrate Toxicity Due to Both Excess and Deficiency

Essential elements such as copper and manganese may demonstrate U‐shaped exposure‐response relationships due to toxic responses occurring as a result of both excess and deficiency. Previous work on a copper toxicity database employed CatReg, a software program for categorical regression developed by the U.S. Environmental Protection Agency, to model copper excess and deficiency exposure‐response relationships separately. This analysis involved the use of a severity scoring system to place diverse toxic responses on a common severity scale, thereby allowing their inclusion in the same CatReg model. In this article, we present methods for simultaneously fitting excess and deficiency data in the form of a single U‐shaped exposure‐response curve, the minimum of which occurs at the exposure level that minimizes the probability of an adverse outcome due to either excess or deficiency (or both). We also present a closed‐form expression for the point at which the exposure‐response curves for excess and deficiency cross, corresponding to the exposure level at which the risk of an adverse outcome due to excess is equal to that for deficiency. The application of these methods is illustrated using the same copper toxicity database noted above. The use of these methods permits the analysis of all available exposure‐response data from multiple studies expressing multiple endpoints due to both excess and deficiency. The exposure level corresponding to the minimum of this U‐shaped curve, and the confidence limits around this exposure level, may be useful in establishing an acceptable range of exposures that minimize the overall risk associated with the agent of interest.     

“无”沿着延异的踪迹走向“有”——用德里达的延异理论诠释老子的“无”

＂无＂沿着延异的踪迹就会走向它的反面——＂有＂,＂无＂就是＂有＂。＂无＂这一能指符号是对感性直观上缺席的事物的不在场的替补,感性直观上缺席的事物在非理性直观上却是在场之物。从感性直观来看,＂无＂是无形的;从非理性直观来说,＂无＂却是有形的。正是因为＂无＂就是＂有＂,并且＂无＂还是有形的,所以人们才能以＂无＂为用、以＂无为＂为＂有为＂。虽然＂无＂就是＂有＂,但是＂无＂又不同于＂有＂,不同形式的＂无＂是不同形式的＂有＂,＂无＂和＂有＂构成差异的嬉戏系统。＂无＂和＂有＂都不能单独存在,二者只能存在于这一差异的嬉戏系统之中。＂无＂和＂有＂的关系体现了语言的游戏性。游戏性的语言为人们建构一个开放的、自由的、诗意的生活世界提供了可能。     

辽东湾海蜇管理制度变迁的逻辑分析

近年来,作为辽东湾沿海渔民主要收入来源的海蜇遭到过度捕捞,资源日益枯竭,因此海蜇资源管理就成为渔政部门一个十分棘手的问题。从辽东湾海蜇管理制度的变迁,即从渔业管理制度的供需、均衡以及变迁,可以发现辽东湾海蜇管理制度变迁是一个分层次的向上逻辑演进。     

社会性别视阈下的启蒙困境——以五四新文化运动之塑造新女性为例

从性别视角考察五四新文化运动,新女性的塑造主要由男性倡导和推动,旨在实现中国社会的现代转型。致使新女性遭遇的诸多困境,凸显出个人解放与社会制度转型的矛盾,女性解放与男权中心为基础的社会运动之间的冲突。延伸到其后中国共产党把妇女解放统摄到阶级、社会解放的出路选择,女性获得的始终是在不触动男权制的权力框架内的有限解放。     

从跨文化角度看英语异形诗的汉译

古今中外的异形诗，大部分追求内容和形式的完美统一。有些英语异形诗可以译成汉语，不少人在这方面做过成功的尝试。但有些英语异形诗很难译成汉语，主要原因在于两种语言文化之间的差异，这些异形诗只能通过其自身的语言文化去欣赏     

Underground storage tanks (UST): A closer investigation statistical implications to changing the shape of a UST

ABSTRACT

Gasoline service stations that use underground storage tanks (UST) assume that the manufactured tank is an ideal cylindrical shape. This cross-sectional shape plays a crucial role in determining a functional form for the volume of liquid that remains inside the tank. In industry, these formulas are used to compute strapping charts. But realistically, the manufacture, assembly, and installation of a tank may have deviation from the actual tank design (for which strapping charts had been developed). A theoretical volume function (based on tank dimensions) is used alongside of statistical methodology to reconcile volume differences in gasoline dispensed at the pump meters versus that displaced inside the tank. Statistical inventory reconciliation of this nature falls within the family of leak detection methods approved by the EPA (Environmental Protection Agency) and the California Water Resources Board. This methodology can also be used to assess deformation of the cross-sectional shape of the tank. We consider a deformation to an ellipse. Through simulation, we estimate the tank dimensions based on a nonlinear model with normal errors. The use of normal errors naturally facilitates a likelihood ratio test. Through this exploration, an approximation function is developed to help improve the power of the likelihood ratio test.