Herdsmen militancy and humanitarian crisis in Nigeria: A theoretical briefing

This article explores the phenomenon of herdsmen militancy as a new trajectory for the farmer–herder crisis in Nigeria, with reference to its humanitarian implications. Relying on a systematic analysis of secondary data and aligning with the analytical anchorage of liberal political ecology theory, the article posits that herdsmen militancy depicts a contradiction in agrarian relations in the context of a national security crisis which has been complicated by salient socio-ecological factors such as climate change, armed violence, and identity politics. In view of the dire humanitarian consequences of this situation, the article submits that herdsmen militancy constitutes a major threat to human and national security in Nigeria. It makes a case for a pragmatic policy capable of mitigating the myriad socio-ecological factors that tend to trigger herdsmen militancy, with prohibition on open grazing in critical hotbeds of herder–farmer conflict as a strategic measure.     

New purification algorithms for linear programming

Two new algorithms are presented for solving linear programs which employ the opposite-sign property defined for a set of vectors in m space. The first algorithm begins with a strictly positive feasible solution and purifies it to a basic feasible solution having objective function value no less under maximization. If this solution is not optimal, then it is drawn back into the interior with the same objective function value, and a restart begins. The second algorithm can begin with any arbitrary feasible point. If necessary this point is purified to a basic feasible solution by dual-feasibility–seeking directions. Should dual feasibility be attained, then a duality value interval is available for estimating the unknown objective function value. If at this juncture the working basis is not primal feasible, then further purification steps are taken tending to increase the current objective function value, while simultaneously seeking another dual feasible solution. Both algorithms terminate with an optimal basic solution in a finite number of steps.     

Production lot sizing under setup and worker learning

Previous lot-sizing models incorporating learning effects focus exclusively on worker learning. We extend these models to include the presence of setup learning, which occurs when setup costs exhibit a learning curve effect as a function of the number of lots produced. The joint worker/setup learning problem can be solved to optimality by dynamic programming. Computational experience indicates, however, that solution times are sensitive to certain problem parameters, such as the planning horizon and/or the presence of a lower bound on worker learning. We define a two-phase EOQ-based heuristic for the problem when total transmission of worker learning occurs. Numerical results show that the heuristic consistently generates solutions well within 1% of optimality.     

The Just Warrior Ethos: A Response to Colonel Riza

In 2014, Colonel M. Shane Riza published an article in this journal arguing that remotely piloted aircraft (RPA) and robotic weapons threaten the US Air Force’s warrior ethos. Riza has clearly articulated the sentiments of one side of a vibrant debate within our service. This paper presents an alternative view; a view held by some who have experienced these new forms and tools of war, and who have wrestled with their implications first-hand. In this paper, we address some methodological concerns with Riza’s approach and then engage some misunderstandings about RPA’s relationship to military history and to risk. The second part of this paper takes a close look at some of the early Just War thinkers to determine what implications the tradition may have on the warrior ethos. We propose, as an alternative to Riza’s position, a return to an ethos grounded in humility, charity, and a conception of war as a last resort; in short, a return to the Just Warrior Ethos.     

Parallel machine scheduling with batch deliveries to minimize total flow time and delivery cost

Motivated by the flow of products in the iron and steel industry, we study an identical and parallel machine scheduling problem with batch deliveries, where jobs finished on the parallel machines are delivered to customers in batches. Each delivery batch has a capacity and incurs a cost. The objective is to find a coordinated production and delivery schedule that minimizes the total flow time of jobs plus the total delivery cost. This problem is an extension of the problem considered by Hall and Potts, Ann Oper Res 135 (2005) 41–64, who studied a two‐machine problem with an unbounded number of transporters and unbounded delivery capacity. We first provide a dynamic programming algorithm to solve a special case with a given job assignment to the machines. A heuristic algorithm is then presented for the general problem, and its worst‐case performance ratio is analyzed. The computational results show that the heuristic algorithm can generate near‐optimal solutions. Finally, we offer a fully polynomial‐time approximation scheme for a fixed number of machines. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 492–502, 2016     

A Reversal of Fortunes? Extended Deterrence and Assurance in Europe and East Asia1

ABSTRACT

The extended deterrence relationships between the United States and its allies in Europe and East Asia have been critical to regional and global security and stability, as well as to nonproliferation efforts, since the late 1950s. These relationships developed in different regional contexts, and reflect differing cultural, political and military realities in the US allies and their relations with the United States. Although extended deterrence and assurance relations have very different histories, and have to some extent been controversial through the years, there has been a rethinking of these relations in recent years. Many Europeans face a diminished threat situation as well as economic and political pressures on the maintenance of extended deterrence, and are looking at the East Asian relationships, which do not involve forward deployed forces as more attractive than NATO’s risk-and-burden-sharing concepts involving the US nuclear forces deployed in Europe. On the other hand, the East Asian allies are looking favorably at NATO nuclear consultations, and in the case of South Korea, renewed US nuclear deployments (which were ended in 1991), to meet increased security concerns posed by a nuclear North Korea and more assertive China. This paper explores the history of current relationships and the changes that have led the allies to view those of others as more suitable for meeting their current needs.     

The collection depots location problem on networks

In this paper we investigate the collection depots location problem on a network. A facility needs to be located to serve a set of customers. Each service consists of a trip to the customer, collecting materials, dropping the materials at one of the available collection depots and returning to the facility to wait for the next call. Two objectives are considered: minimizing the weighted sum of distances and minimizing the maximum distance. The properties of the solutions to these problems are described. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 15–24, 2002; DOI 10.1002/nav.10000     

Flexible supply contracts for short life‐cycle goods: The buyer's perspective

In this paper we analyze a two‐period supply contract which allows for order adjustment by the buyer. The buyer is required to place orders for two periods. After observing initial demand, the buyer is then allowed to adjust the second order, paying a per unit order adjustment penalty. We describe the optimal behavior of the buyer under such a contract, both in determining the initial order quantities and in subsequently adjusting the order. We compare the solution to a contract where no adjustment is allowed and to the case where adjustment is allowed without penalty. We demonstrate that flexible contracts can reduce the potentially negative effect of correlation of demand between two periods. Further, we investigate how the duration of the first period vis‐à‐vis the second period affects the profitability of the buyer as a function of the degree of correlation. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 25–45, 2002; DOI 10.1002/nav.10002