Increased Chinese and American defence involvement in Africa

There is often a perception put forth of a fight for supremacy between China and the USA. This is often the case when discussing the continent of Africa. Both countries have recently increased their involvement in Africa for a variety of reasons. In 2011, China surpassed the USA as Africa's largest trading partner, with Africa predicted to be Beijing's largest trading partner by 2017. As expected, their bilateral and multilateral defence cooperation with strategic countries and organisations has matured and expanded along with it. Washington's own economic interests, al-Qa'ida and threats to maritime security are some of the crucial elements behind the US's presence on the continent. This article analyses both the USA and China's rising defence involvement in Africa. It compares and contrasts their similarities and differences, and argues that cooperation in certain areas can prove beneficial for all parties involved.     

THE PROLIFERATION SECURITY INITIATIVE

The Asia-Pacific is emerging as a critical region in the fight against the proliferation of weapons of mass destruction. The Proliferation Security Initiative (PSI) is an aggressive global strategy designed to interdict the transport of these weapons and associated technologies. However, some observers have suggested that the Asia-Pacific has given the PSI a less than enthusiastic reception. The authors posit a more sanguine view. They caution against taking such a holistic approach to the region. Asia does not speak with one voice when it comes to security, and opposition to the PSI is not as widespread nor deep-rooted as may have been anticipated. In addition, the PSI's informal structure encourages flexibility, enabling states to participate in certain activities while eschewing others that may be technically or politically untenable.     

Crane scheduling with spatial constraints

In this work, we examine port crane scheduling with spatial and separation constraints. Although common to most port operations, these constraints have not been previously studied. We assume that cranes cannot cross, there is a minimum distance between cranes and jobs cannot be done simultaneously. The objective is to find a crane‐to‐job matching which maximizes throughput under these constraints. We provide dynamic programming algorithms, a probabilistic tabu search, and a squeaky wheel optimization heuristic for solution. Experiments show the heuristics perform well compared with optimal solutions obtained by CPLEX for small scale instances where a squeaky wheel optimization with local search approach gives good results within short times. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

Stochastic duels with displacements (suppression)

The stochastic duel is extended to include the possibility of a near-miss on each round fired, which causes the opponent to displace. During displacement, the displacing contestant cannot return the fire but is still a target for his opponent. An alternative interpretation of this model is to consider the displacement time as the time a contestant's fire is suppressed by his opponent's fire and that he does not move, but merely ceases fire temporarily. All times are exponentially distributed.     

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     

A chessboard model of the U‐boat war in the Atlantic with applications to signals intelligence

This paper uses a simple Monte Carlo model to analyze the influence of signals intelligence on the Second World War's Battle of the Atlantic. The principle measure of effectiveness is the number of U‐boat days of attack to which convoys were subjected. A secondary measure is the number of convoyed ships sunk. The model is validated against historical data and then used to explore the effectiveness of the two sides' signals intelligence. Allied use of signals intelligence is shown to have been capable of completely offsetting German use of signals intelligence, and then some. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2005