Spatial pricing and product allocation in online retailing

Spatial pricing means a retailer price discriminates its customers based on their geographic locations. In this article, we study how an online retailer should jointly allocate multiple products and facilitate spatial price discrimination to maximize profits. When deciding between a centralized product allocation ((i.e., different products are allocated to the same fulfillment center) and decentralized product allocation (ie, different products are allocated to different fulfillment centers), the retailer faces the tradeoff between shipment pooling (ie, shipping multiple products in one package), and demand localization (ie, stocking products to satisfy local demand) based on its understanding of customers' product valuations. In our basic model, we consider two widely used spatial pricing policies: free on board (FOB) pricing that charges each customer the exact amount of shipping cost, and uniform delivered (UD) pricing that provides free shipping. We propose a stylized model and find that centralized product allocation is preferred when demand localization effect is relatively low or shipment pooling benefit is relatively high under both spatial pricing policies. Moreover, centralized product allocation is more preferred under the FOB pricing which encourages the purchase of virtual bundles of multiple products. Furthermore, we respectively extend the UD and FOB pricing policies to flat rate shipping (ie, the firm charges a constant shipping fee for each purchase), and linear rate shipping (ie, the firm sets the shipping fee as a fixed proportion of firm's actual fulfillment costs). While similar observations from the basic model still hold, we find the firm can improve its profit by sharing the fulfillment cost with its customers via the flat rate or linear rate shipping fee structure.     

Pricing and capacity allocation strategies: Implications for manufacturers with product sharing

Emerging sharing modes, like the consumer-to-consumer (C2C) sharing of Uber and the business-to-consumer (B2C) sharing of GoFun, have considerably affected the retailing markets of traditional manufacturers, who are motivated to consider product sharing when making pricing and capacity decisions, particularly electric car manufacturers with limited capacity. In this paper, we examine the equilibrium pricing for a capacity-constrained manufacturer under various sharing modes and further analyze the impact of capacity constraint on the manufacturer's sharing mode selection as well as equilibrium outcomes. We find that manufacturers with low-cost products prefer B2C sharing while those with high-cost products prefer C2C sharing except when the sharing price is moderate. However, limited capacity motivates manufacturers to enter into the B2C sharing under a relatively low sharing price, and raise the total usage level by sharing high-cost products. We also show that the equilibrium capacity allocated to the sharing market with low-cost products first increases and then decreases. Finally, we find that sharing low-cost products with a high limited capacity leads to a lower retail price under B2C sharing, which creates a win-win situation for both the manufacturer and consumers. However, sharing high-cost products with a low limited capacity creates a win-lose situation for them.     

Callable products with dependent demands

Capacity providers such as airlines often sell the same capacity to different market segments at different prices to improve their expected revenues. The absence of a secondary market, due to the nontransferability of airline tickets, gives rise to an opportunity for airlines to broker capacity between consumers with different willingness to pay. One way to broker capacity is by the introduction of callable products. The idea is similar to callable bonds where the issuer has the right, but not the obligation, to buy back the bonds at a certain price by a certain date. The idea of callable products was introduced before under the assumption that the fare-class demands are all independent. The independent assumption becomes untenable when there is significant demand recovery (respectively, demand cannibalization) when lower fares are closed (respectively, opened). In this case, consumer choice behavior should be modeled explicitly to make meaningful decisions. In this paper, we consider a general consumer choice model and develop the optimal strategy for callable products. Our numerical study illustrates how callable products are win-win-win, for the capacity provider and for both high and low fare consumers. Our studies also identify conditions for callable products to result in significant improvements in expected revenues.     

入射频率对高功率微波与等离子体相互作用的影响分析

通过建立等离子体中的波动方程、电子传递方程和重物质传递方程,研究了等离子体对高功率微波传输特性的影响。研究了高功率微波与等离子体相互作用中产生的电子密度和透射电场的变化过程,并重点分析了变化过程中入射波频率产生的影响。研究结果表明,在相互作用过程中,等离子体中的电子密度和透射电场在一定条件下会发生阶跃变化,即等离子体区域平均电子数密度会在极短的时间内由1×10~9m~(-3)增加到1×10~(19)m~(-3),平均电场强度也会由初始场强跃变为零,并且这种变化的产生存在一定的入射阈值场强和最低产生时间。当入射电磁波的频率不同时,产生阶跃变化所需的场强阈值和最低产生时间就会变得不同,高功率微波与等离子体相互作用中存在一定的色散效应。在所考虑的范围内,阈值场强随入射波频率线性增长,而最低产生时间随电磁波频率呈非线性增长变化。     

Theories of Non-Balancing and Russia’s Foreign Policy

The beginning of the twenty-first century has witnessed the emergence of balancing responses to the US hegemony, among which Russia’s foreign policies stand out as corresponding to what is understood as ‘hard balancing.’ Why is the United States being balanced against? This paper categorizes the existing theories of non-balancing into six conditions that together guarantee the absence of balancing and demonstrates that the current unipolar system can satisfy only one of them. This eases the systemic constraints and makes balancing possible. The paper then presents three cases of balancing with reference to President Putin’s foreign policy. It argues that even though in terms of relative military capabilities unipolarity still holds, the emergence of counter-hegemonic balancing is indicative of important changes in the nature of post-Cold War American domination.     

Effective in battle: conceptualizing soldiers’ combat effectiveness*

How do we understand combat effectiveness – soldiers’ performance in battle? Despite the broad consensus that understanding combat effectiveness is important both for scholars and policymakers, there is widespread disagreement about what combat effectiveness is. More specifically, studies of effectiveness tend to focus on either the skill of soldiers in battle, or their will to fight. Yet both skill and will are essential components of an effective fighting force. This article argues that understanding combat effectiveness requires understanding both of these key components of effectiveness. In other words, combat effectiveness requires both the skill and will to engage the enemy in an organized manner. It then demonstrates the usefulness of this conceptualization by applying it to the cases of British, Indian, and Australian forces fighting the Japanese during the Second World War. Only when scholars are talking about the same concept will our understanding of the conditions under which militaries are effective in battle progress. By comparing different units fighting the same opponent under the same material conditions, I demonstrate that units vary both in their combat skill and their will to fight, and that understanding their effectiveness in battle requires analyzing both of these key factors.     

舰船主动力装置故障隔离与参数估计方法

针对舰船主动力装置结构复杂、故障种类多和系统不确定性等故障诊断问题,提出采用基于双因果键合图模型的定量故障隔离与参数估计方法。根据系统传感器配置方案,建立双因果键合图模型,通过因果路径分析,推导得到系统解析冗余关系,并获得故障特征矩阵。建立系统线性分式变换键合图模型,开展故障仿真,将其与双因果键合图模型耦合,在MATLAB/Simulink环境中进行仿真试验,实现了舰船主动力装置的故障隔离与参数估计。结果表明：对双因果键合图模型因果路径分析,可以避免手动推导系统解析冗余关系的繁杂过程;基于其部件构造方程的分析可以有效实现系统故障隔离与参数估计,实时跟踪和预测故障状态。     

电磁发射用脉冲功率电源放电建模分析

为高效研究电磁发射用脉冲功率电源放电性能,为电磁发射提供技术支持,降低研发成本,电磁发射过程的相关建模与仿真工作需要重点研究。对弹丸在轨道中实际运动物理过程建立数学模型,对脉冲功率电源建立电路模型,采用联合两种模型的方法对脉冲功率电源放电系统进行研究,提出一种基于发射过程多物理现象的脉冲功率电源放电系统仿真模型。通过实验验证了提出方法的有效性,为后续脉冲功率电源放电研究提供了依据。     

能量均衡的围捕任务分配方法

随着水下机器人反围捕策略研究的不断深入,水下机器人围捕变得越来越困难。为此构建一种多层环状伏击围捕模型并设计了基于围捕任务的任务分配方法,使得水下机器人能够充分利用自身的特点更好地完成任务。同时,考虑在围捕过程中随时间推移,系统内能量会出现消耗不均的现象,据此提出一种能量均衡方法平衡系统能量的消耗。实验证明所提出的基于多层环状围捕模型的能量均衡策略任务分配方法能有效提高围捕成功率,延长系统寿命。     

Evergreening and operational risk under price competition

“Evergreening” is a strategy wherein an innovative pharmaceutical firm introduces an upgrade of its current product when the patent on this product expires. The upgrade is introduced with a new patent and is designed to counter competition from generic manufacturers that seek to imitate the firm's existing product. However, this process is fraught with uncertainty because the upgrade is subject to stringent guidelines and faces approval risk. Thus, an incumbent firm has to make an upfront production capacity investment without clarity on whether the upgrade will reach the market. This uncertainty may also affect the capacity investment of a competing manufacturer who introduces a generic version of the incumbent's existing product but whose market demand depends on the success or failure of the upgrade. We analyze a game where capacity investment occurs before uncertainty resolution and firms compete on prices thereafter. Capacity considerations that arise due to demand uncertainty introduce new factors into the evergreening decision. Equilibrium analysis reveals that the upgrade's estimated approval probability needs to exceed a threshold for the incumbent to invest in evergreening. This threshold for evergreening increases as the intensity of competition in the generic market increases. If evergreening is optimal, the incumbent's capacity investment is either decreasing or nonmonotonic with respect to low end market competition depending on whether the level of product improvement in the upgrade is low or high. If the entrant faces a capacity constraint, then the probability threshold for evergreening is higher than the case where the entrant is not capacity constrained. Finally, by incorporating the risk‐return trade‐off that the incumbent faces in terms of the level of product improvement versus the upgrade success probability, we can characterize policy for a regulator. We show that the introduction of capacity considerations may maximize market coverage and/or social surplus at incremental levels of product improvement in the upgrade. This is contrary to the prevalent view of regulators who seek to curtail evergreening involving incremental product improvement. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 71–89, 2016