Capacitated lot‐sizing and scheduling with parallel machines,back‐orders,and setup carry‐over

We address the capacitated lot‐sizing and scheduling problem with setup times, setup carry‐over, back‐orders, and parallel machines as it appears in a semiconductor assembly facility. The problem can be formulated as an extension of the capacitated lot‐sizing problem with linked lot‐sizes (CLSPL). We present a mixed integer (MIP) formulation of the problem and a new solution procedure. The solution procedure is based on a novel “aggregate model,” which uses integer instead of binary variables. The model is embedded in a period‐by‐period heuristic and is solved to optimality or near‐optimality in each iteration using standard procedures (CPLEX). A subsequent scheduling routine loads and sequences the products on the parallel machines. Six variants of the heuristic are presented and tested in an extensive computational study. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

Factors that affect the optimal amount of central control in complex systems

Whereas much of the previous research in complex systems has focused on emergent properties resulting from self‐organization of the individual agents that make up the system, this article studies one vital role of central organization. In particular, four factors are conjectured to be key in determining the optimal amount of central control. To validate this hypothesis, these factors are represented as controllable parameters in a mathematical model. For different combinations of parameter values, the optimal amount of central control is found, either analytically or by computer simulation. The model is shown to provide results that match well with the level of control found across a broad spectrum of specific complex systems. This model also provides general guidelines as to how combinations of these factors affect the desirable level of control and specific guidelines for selecting and evaluating leaders. These results indicate that all of these factors, though not exhaustive, should be considered carefully when attempting to determine the amount of control that is best for a system. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

The impact of military expenditures on economic growth in the less developed countries∗

This paper presents the results of empirical research on the economic impact of military expenditure — milex — on the less developed countries. The hypothesis is that the impact on growth is a combination of three effects: (1) increased security — positive impact; (2) diversion of resources from productive investment — negative impact; and (3) pressure for more efficient government policies in response to the external threat — positive impact. The combination of these effects would produce a non‐linear relationship with the growth rate at first increasing as milex increased and then decreasing. For the full sample of 71 countries, we found the predicted relationship, however, it is not robust to changes in the sample. The robust conclusion is that there was no evidence of a negative impact of military spending on economic growth.     

Aligning national “logics” in a European military helicopter program

This article analyzes the public side of the NH90 network consisting of four participating countries (Germany, France, Italy, and the Netherlands) and their industrial partners. Comparable to observations in earlier international projects in the defense sector, the development and production of the NH90 defense helicopter did not match original plans and costs estimates. On the basis of four mechanisms that were intended to facilitate the cooperation between the partnering countries (the General Memorandum of Understanding; coalition formation; the role of the central agency; and the process of vertical escalation) the question is posed whether or not there was a true alignment of national interests and “logics.” The lack of standardization, as well as program delays and issues concerning the division of the work-share, lead to the emerging alignment being characterized as “quasi-alignment” at best.     

An inventory depletion problem with random and age-dependent lifetimes

The following problem is studied. The units of an inventory are used one by one until all have failed. Their lifetimes decrease with their ages, when they are taken out of the inventory. An item of age a is supposed to have a lifetime Y exp(-a), where Y is a random variable which does not depend on a. It is shown that in order to maximize the total lifetime the items should be taken according to the LIFO principle. This is shown for a certain class of distributions of Y. This class includes the exponential and the Pareto distributions.     

Dangerous work: Terrorism against U.S. diplomats

The goal of diplomats is to represent their countries’ interests through diplomacy, not arms. Because they are not military personnel, they may be perceived as at lower risk of being the target of terrorists. However, recent events have called this perception into question. Despite this danger, there has been little research on terrorist attacks against diplomats. Drawing on the terrorism studies literature, this article argues that diplomats are targeted more than non-diplomatic targets in countries where certain U.S. foreign policies are implemented. An empirical analysis of 471 attacks against U.S. diplomats from 1970 to 2011 reveals that while U.S. alliances and foreign aid increase the likelihood of attacks against diplomats, U.S. military intervention and civil war, on the other hand, increase the risk of terrorism against non-diplomatic targets. This finding is relevant because it shows terrorist attacks against diplomats result from certain types of foreign policy.     

A Revolution Too Far? US Defence Innovation,Europe and NATO’s Military-Technological Gap

The United States is launching another defence innovation initiative to offset the growing military-technological might of countries such as China, Russia and Iran. However, by utilising emerging technologies from the commercial sector to achieve greater military power the US may further open up the technology gap within NATO. This raises serious questions for NATO’s European allies. This article probes the nature of the US’s latest innovation strategy and sets it within the strategic context facing Europe today. Whether European governments, firms and militaries will join the US in its new defence innovation drive will hinge on politico-military and industrial considerations.