Transshipment through crossdocks with inventory and time windows

A major challenge in making supply meet demand is to coordinate transshipments across the supply chain to reduce costs and increase service levels in the face of demand fluctuations, short lead times, warehouse limitations, and transportation and inventory costs. In particular, transshipment through crossdocks, where just‐in‐time objectives prevail, requires precise scheduling between suppliers, crossdocks, and customers. In this work, we study the transshipment problem with supplier and customer time windows where flow is constrained by transportation schedules and warehouse capacities. Transportation is provided by fixed or flexible schedules and lot‐sizing is dealt with through multiple shipments. We develop polynomial‐time algorithms or, otherwise, provide the complexity of the problems studied. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005     

The elephant in the room: US ballistic missile defence under Barack Obama

Conventional wisdom seems to hold that under Barack Obama, the US ballistic missile defence programme has been pushed aside to allow for a refreshed domestic and international agenda. Proponents point to Obama's campaign thinking and rhetoric, the ballistic missile defence (BMD) budget cuts, the decision to end the Third Site in Europe, and the reset relations with Russia through the New Strategic Arms Reduction Treaty (New START) as evidence that the programme has undergone a significant period of change, retraction and rationalisation. This article argues instead that BMD has not fallen from prominence and that there is a change in focus rather than retraction of its strategic goal. Consequently, BMD continues to grow in importance as a component of US national security strategy.     

Europe's new subregionalism

From the Barents and the Baltic Sea in the north, through Central Europe and the Balkans, to the Black Sea in the south a range of new subregional groups and cooperation processes have emerged in Europe during the 1990s. Compared to NATO and the European Union, these new subregional groups have received little attention. Their ‘indirect approach’ to security, however, plays an important role in overcoming the legacy of the Cold War, reducing the risks of military conflict and addressing non‐military security challenges. As NATO and the EU expand eastwards, subregionalism is assuming growing importance as a means of avoiding new ‘dividing lines’ in Europe. After the wars in Bosnia and Kosovo, subregionalism is also gaining importance as a means of building cooperation in South‐Eastern Europe. The challenge for the future is to give more substance and depth to Europe's new subregional cooperation frameworks.     

Plague and Paradox: Militias in Iraq

Politicians, political pundits, and others focus a lot of attention on the political militias in Iraq, usually blaming them for their destabilising effect on the country and insisting that they disband. This study examines the impact that the militias in Iraq have on the Iraqi government's ability to consolidate control over its territory by first explaining how militias rose to prominence in Iraq during the power vacuum created by Saddam Hussein's ousting, then analysing the many ways militias adversely impact the security situation. The study then examines the other side of the argument – that is, why militias enjoy so much support in Iraq among their constituencies, and why they may actually be necessary to achieve stability in Iraq in the short term.     

A robust sensor covering and communication problem

We consider the problem of placing sensors across some area of interest. The sensors must be placed so that they cover a fixed set of targets in the region, and should be deployed in a manner that allows sensors to communicate with one another. In particular, there exists a measure of communication effectiveness for each sensor pair, which is determined by a concave function of distance between the sensors. Complicating the sensor location problem are uncertainties related to sensor placement, for example, as caused by drifting due to air or water currents to which the sensors may be subjected. Our problem thus seeks to maximize a metric regarding intrasensor communication effectiveness, subject to the condition that all targets must be covered by some sensor, where sensor drift occurs according to a robust (worst‐case) mechanism. We formulate an approximation approach and develop a cutting‐plane algorithm to solve this problem, comparing the effectiveness of two different classes of inequalities. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 582–594, 2015     

Acceptance sampling,imperfect production,and the optimality of zero defects

Acceptance sampling is often used to monitor the quality of raw materials and components when product testing is destructive, time-consuming, or expensive. In this paper we consider the effect of a buyer-imposed acceptance sampling policy on the optimal batch size and optimal quality level delivered by an expected cost minimizing supplier. We define quality as the supplier's process capability, i.e., the probability that a unit conforms to all product specifications, and we assume that unit cost is an increasing function of the quality level. We also assume that the supplier faces a known and constant “pass-through” cost, i.e., a fixed cost per defective unit passed on to the buyer. We show that the acceptance sampling plan has a significant impact on the supplier's optimal quality level, and we derive the conditions under which zero defects (100% conformance) is the policy that minimizes the supplier's expected annual cost. © 1997 John Wiley & Sons, Inc. Naval Research Logistics 44: 515–530, 1997     

Birth of the Cold War: irregular warfare first blood in Greece

ABSTRACT

While often held up as a model of successful American counterinsurgency, the Greek Civil War presents a unique case. Peculiar local conditions and geopolitics contributed to the defeat of communist forces in Greece. A firm British and later American commitment to combating communism stood in contrast to ambiguous support from the Soviet Union in an area they considered outside of their sphere of influence. Strong nationalist feeling among the Greek population buttressed support for the government and undermined the ‘internationalist’ concessions of communist forces. These characteristics make the extrapolation of broader lessons focused on victory through the application of overwhelming American resources and the financing of local forces problematic. If lessons are to be gleaned from this case, they should focus on the critical roles played by internal political dynamics and geopolitics in undermining the strength of the insurgent forces and how these provided a stable platform from which the counterinsurgents could operate.