Assessing the value of demand sharing in supply chains

We consider the problem of assessing the value of demand sharing in a multistage supply chain in which the retailer observes stationary autoregressive moving average demand with Gaussian white noise (shocks). Similar to previous research, we assume each supply chain player constructs its best linear forecast of the leadtime demand and uses it to determine the order quantity via a periodic review myopic order‐up‐to policy. We demonstrate how a typical supply chain player can determine the extent of its available information in the presence of demand sharing by studying the properties of the moving average polynomials of adjacent supply chain players. The retailer's demand is driven by the random shocks appearing in the autoregressive moving average representation for its demand. Under the assumptions we will make in this article, to the retailer, knowing the shock information is equivalent to knowing the demand process (assuming that the model parameters are also known). Thus (in the event of sharing) the retailer's demand sequence and shock sequence would contain the same information to the retailer's supplier. We will show that, once we consider the dynamics of demand propagation further up the chain, it may be that a player's demand and shock sequences will contain different levels of information for an upstream player. Hence, we study how a player can determine its available information under demand sharing, and use this information to forecast leadtime demand. We characterize the value of demand sharing for a typical supply chain player. Furthermore, we show conditions under which (i) it is equivalent to no sharing, (ii) it is equivalent to full information shock sharing, and (iii) it is intermediate in value to the two previously described arrangements. Although it follows from existing literature that demand sharing is equivalent to full information shock sharing between a retailer and supplier, we demonstrate and characterize when this result does not generalize to upstream supply chain players. We then show that demand propagates through a supply chain where any player may share nothing, its demand, or its full information shocks (FIS) with an adjacent upstream player as quasi‐ARMA in—quasi‐ARMA out. We also provide a convenient form for the propagation of demand in a supply chain that will lend itself to future research applications. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 515–531, 2014     

Poachers turned gamekeepers: A study of the guerrilla phenomenon in Spain, 1808–1840

This article modifies the associations made by historians and political scientists of Spanish guerrilla warfare with revolutionary insurgency. First, it explains how the guerrilla phenomenon moved from a Leftist to a reactionary symbol. Second, it compares the insurgency and counter-insurgency features of the Carlist War (1833–1840) with those of the better-known Peninsular War (1808–1814). Third, it shows how erstwhile guerrilla leaders during the Carlist War made their expertise available to the counter-insurgency, in a socio-economic as well as military setting. This article revises the social banditry paradigm in nineteenth-century Spain in the under-researched context of Europe bloodiest nineteenth-century civil war.     

多无人机协同任务分配方法

任务分配是多UCAV协同控制的核心和有效保证,是一类复杂的多目标优化问题。针对一种扩展的混合整数线性规划(MILP)任务分配模型,通过对模型特点的分析,提出一种基于相似度的遗传退火算法解决该问题并进行仿真实验,仿真结果表明该算法具有较强的收敛性和较好的多样性,验证了改进算法解决该问题模型的有效性。     

The African Peace and Security Architecture and its partners

This article presents survey data on the African Peace and Security Architecture (APSA). It focuses explicitly on two aspects: the internal constitution and achievements of the APSA; and coordination and cooperation with external actors, such as Regional Economic Communities, the United Nations and the European Union. The survey, conducted between October 2011 and December 2012, targeted 198 security experts in international organisations, think tanks, academia and non-governmental organisations. It reveals the APSA's current stage of development, achievements and challenges.     

The political economy of drones

This paper provides a political economy analysis of the evolution of unmanned aerial vehicles (UAV), or ‘drones’ in the USA. Focus is placed on the interplay between the polity and private economic influences, and their impact on the trajectory of political, economic, and military outcomes. We identify the initial formation of the drone industry, trace how the initial relationships between the military and the private sector expanded over time, and discuss present relationships. Understanding the historical evolution of UAV technology, as well as the major players in the industry today, is important for ongoing policy debates regarding the use of drones both domestically and internationally.     

Al粉对硝化甘油分解释放NO_2的影响

为研究硝化甘油中加入Al粉对NO2释放的影响,运用计算化学分子模拟手段对两者共存条件下的相关反应进行初步分析.试验结果表明,在硝化甘油中加入Al粉,将会降低硝化甘油分解反应的难度,同时放出大量的热.     

TERRORISM: FACTS FROM FIGURES 1

If international terrorism is on a rising trend, an important source of confirmation or refutation of this is time‐series data on terrorist activity. Using chiefly data collected by the RAND/MIPT consortium we show using basic statistical analysis that in the period 1968–2005 the yearly number of all international terrorist incidents shows no trend over time, but fluctuates year on year in a random manner. On the other hand some indicators do show a definite trend over time, principally the steady rise in the number of incidents that are death‐dealing in nature. A further conclusion is drawn, showing that the proportion of these incidents leading to deaths above a given level is virtually fixed.     

Coordination mechanisms for a three‐stage reverse supply chain to increase profitable returns

In this article, we consider a generic electronic product that can be remanufactured or recycled at the end of its life cycle to generate new profit. We first describe the product return process and then present a customer segmentation model to capture consumers' different behaviors with respect to product return so that the retailer can work more effectively to increase the return volume. In regard to the collaboration between the retailer and the manufacturer, we explore a revenue‐sharing coordination mechanism for achieving a win‐win outcome. The optimality and sensitivity of the critical parameters in four strategies are obtained and examined both theoretically and numerically, which generate insights on how to manage an efficient consumer‐retailer‐manufacturer reverse supply chain, as well as on the feasibility of simplifying such a three‐stage chain structure. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

Lost through non-translation: bringing Clausewitz's writings on ‘new wars’ back in

While Carl von Clausewitz has generally been respected as one of the most profound philosophers of war, his expertise has been regarded as somewhat limited if not even irrelevant to the so-called ‘new wars’ of the post-Cold War world. Many scholars in international relations have claimed that ‘new wars’ are essentially ‘post-Clausewitzian’ and ‘post-trinitarian’ in nature, meaning that they are no longer fathomable through a Clausewitzian framework. However Clausewitz's earlier writings were nearly exclusively dedicated to guerrilla warfare, or what he called ‘small wars’. These writings have been largely overlooked by many analysts of contemporary conflicts. By drawing on his rare and untranslated writings, the article uncovers a critical part of Clausewitz's expertise in asymmetric warfare and shows that, far from being irrelevant in an age where interstate warfare is increasingly being replaced by conflicts between states and semi-/non-state actors, Clausewitz's philosophical writings actually shed new light into the particular interactive dynamics generated during wars waged under conditions of asymmetry.     

带点缺陷的一维亥姆霍兹共振腔声子晶体中缺陷模式

在基于亥姆霍兹共振腔的一维声子晶体中引入点缺陷会在原有局域共振型声禁带内产生缺陷模式。采用传递矩阵法和有限元法分析了缺陷模式随缺陷单元几何尺寸变化关系和声子晶体中声场分布情况。结果表明,随着缺陷单元与完美单元之间耦合程度的增强,缺陷模式从局域共振型禁带中完美单元共振频率处向禁带边缘移动。同时,缺陷模式的存在使得结构中出现了能量局域化的现象。本工作对设计新型声滤波器、能量集中装置具有一定的理论意义。