On the polyhedral structure of two‐level lot‐sizing problems with supplier selection

In this article, we study a two‐level lot‐sizing problem with supplier selection (LSS), which is an NP‐hard problem arising in different production planning and supply chain management applications. After presenting various formulations for LSS, and computationally comparing their strengths, we explore the polyhedral structure of one of these formulations. For this formulation, we derive several families of strong valid inequalities, and provide conditions under which they are facet‐defining. We show numerically that incorporating these valid inequalities within a branch‐and‐cut framework leads to significant improvements in computation. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 647–666, 2017     

The role and capabilities of major weapon systems transferred between 1950 and 2010: Empirical examinations of an arms transfer data set

Arms transfers provide exporters an avenue to provide security to other states while gaining economic benefits. Arms transfers provide importers an avenue to gain security without having to rely on alliances. Past research uses aggregate measures of the monetary or security value of major weapon system transfers without accounting for strategic differences in possible use in interstate and civil conflict. This article presents a data set on interstate transfers of major weapon systems between 1950 and 2010 building upon Stockholm Peach Research Institute’s Arms Trade Register with several improvements. First, it disaggregates land weapons and air weapons into categories reflecting their strategic capabilities. Second, model level characteristics (e.g. age, speed, and range) are drawn from Jane’s Defence sources. Additionally, the data set covers a larger range of time and states than previous data sets categorizing arms. To demonstrate the usefulness, this article first presents summary statistics of the data set and then replicates an earlier test to show that the effect of human rights and regime types on United States transfers differs across the categories of arms compared to alternative measures of arms transfers.     

Preserving defense technologies: A strategy for economic conversion†

This paper presents a model for converting legacy defense production facilities into private‐sector economic resources. Specifically, this paper will examine as a case study the first successful conversion of a former U.S. Department of Energy nuclear weapons production installation, including reasons for its success, its costs and benefits, and lessons for public policy. It is envisioned that this model may be useful for mitigating local economic hardship resulting from defense “downsizing” and for privatizing production capacities critical for national defense.     

Africa Watch

This is the first of a new series of articles in the African Security Review which will focus on specific current issues of importance in Africa. To make sense of events, it is necessary to include some background information in order to contextualise them. As countries are revisited in the series, the background information will become less extensive, and readers will be referred to earlier pieces. Apart from providing an explanatory narrative of emerging situations, an attempt will be made to identify the issues likely to attract attention in the near future, and account for their salience.     

EXPORT CONTROLS AND INTERNATIONAL SAFEGUARDS

Export controls and international safeguards are central to ensuring international confidence in the peaceful uses of nuclear materials and technologies and to achieving adequate oversight on the transfer and use of nuclear materials, technology, and equipment required for the development of proliferation-sensitive parts of the nuclear fuel cycle. Although the independent strengths of export controls and international safeguards rely largely on universal adherence, there may be opportunities to exploit the shared strengths of these systems. This article provides background information on the separate evolution of export controls and international safeguards, considers how these two elements of the nonproliferation regime interact, and identifies some possible avenues that could, over time, lead to wholly integrated activities.     

Counter‐punching on the Mudzi: D Company, 1st Rhodesian African Rifles,on operation ‘Mardon’ 1 November 1976

Designed to harrass and weaken Ian Smith's principal enemy, Robert Mugabe, in his safe haven of Mozambique, Operation ‘Mardon’ involved co‐ordinated incursions over the Rhodesian border on a wide front. The secondary purpose was to persuade the African nationalist insurgents to abandon their incursion routes in the north‐east and south‐east in favour of those from the east where the mountainous terrain favoured their interception. Although other Rhodesian units wreaked more physical damage, D Company, 1st Battalion, the Rhodesian African Rifles, inflicted the heaviest casualties in their classic infantry attack on Mudzi Camp.¹