Approximation methods for the analysis of a multicomponent,multiproduct assemble‐to‐order system

In this article, we consider the performance evaluation of a multicomponent, multiproduct assemble‐to‐order (ATO) system. Each component is managed independently using a base‐stock policy at a supply facility with limited production capacity and an infinite buffer. The arrivals of demands follow a multivariate Poisson process and unfilled demands are backlogged. Because exact analysis of the proposed system is not feasible, we propose two approximation methods which provide upper and lower bounds for various performance measures such as fill rate, average waiting time, and average number of backorders of the proposed system. Our computational experiments demonstrate the effectiveness of the two approximation methods under various system settings. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

Fencing the bear? Explaining US foreign policy towards Russian interventions

Despite the burgeoning literature on Russia’s renewed power politics, little attention has been paid to the fact that US reactions towards Russia’s military interventions were all but coherent. The USA has chosen weak measures in Georgia in 2008 (shaming) compared to its assertive response in Ukraine in 2014 (sanctions, hard deterrence). This article assesses the explanatory power of neorealist, liberal and constructivist theories for the variation in US reactions towards Russian interventions in Georgia and Ukraine. Our argument is that the constructivist perspective explains the cases best as it highlights the power and communality of normative assessments. The Ukraine crisis was perceived by the USA as a violation of core international norms, especially the non-use of force and the principle of territorial integrity. Relevant international norm carriers shared this assessment of the conflict. In contrast, the perception of the Georgian war centred on the issue of democracy promotion. While democracy is an important aim of US foreign policy, it does not summon the same normative importance as general principles of international law. Furthermore, the perception of the Georgian war remained contested among Western allies, which decreased the communality of the normative assessment.     

晃动基座下捷联惯导的初始对准研究

为了降低车体振动对惯性器件输出的影响,运用小波域阈值滤波对信号进行预滤波,介绍一种初始对准非线性误差模型,并运用H∞滤波完成初始对准。针对坦克发动的情况,分别在固定怠速和不同怠速的情况下进行大量重复实验,实验结果表明：该方法能够有效完成坦克发动下初始对准,具有良好的重复性和稳定性。     

PROTECTING CULTURAL MONUMENTS AGAINST TERRORISM

Famous cultural monuments are often regarded as unique icons, making them an attractive target for terrorists. Despite huge military and police outlays, terrorist attacks on important monuments can hardly be avoided. We argue that an effective strategy to discourage terrorist attacks on iconic monuments is for a government to show a firm commitment to swift reconstruction. Using a simple game‐theoretic model, we demonstrate how a credible claim to rebuild any destroyed cultural monument discourages terrorist attacks by altering the terrorists' expectations and by increasing the government's reputation costs if they fail to rebuild.     

A componentwise index of service measurement in multi‐component systems

In this paper we present a componentwise delay measure for estimating and improving the expected delays experienced by customers in a multi‐component inventory/assembly system. We show that this measure is easily computed. Further, in an environment where the performance of each of the item delays could be improved with investment, we present a solution that aims to minimize this measure and, in effect, minimizes the average waiting time experienced by customers. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 50: 2003     

Return policy: Hassle‐free or your money‐back guarantee?

This article compares the profitability of two pervasively adopted return policies—money‐back guarantee and hassle‐free policies. In our model, a seller sells to consumers with heterogeneous valuations and hassle costs. Products are subject to quality risk, and product misfit can only be observed post‐purchase. While the hassle‐free policy is cost advantageous from the seller's viewpoint, a money‐back guarantee allows the seller to fine‐tune the consumer hassle on returning the product. Thus, when the two return policies lead to the same consumer behaviors, the hassle‐free policy dominates. Conversely, a money‐back guarantee can be more profitable even if on average, high‐valuation consumers experience a lower hassle cost than the low‐valuation ones. The optimal hassle cost can be higher when product quality gets improved; thus, it is not necessarily a perfect proxy or signal of the seller's quality. We further allow the seller to adopt a mixture of these policies, and identify the concrete operating regimes within which these return policies are optimal among more flexible policies. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 403–417, 2014