Interval estimation of a global optimum for large combinatorial problems

Consider an “intractable” optimization problem for which no efficient solution technique exists. Given a systematic procedure for generating independent heuristic solutions, we seek to obtain interval estimates for the globally optimal solution using statistical inference. In previous work, accurate point estimates have been derived. Determining interval estimates, however, is a considerably more difficult task. In this paper, we develop straightforward procedures which compute confidence intervals efficiently in order to evaluate heuristic solutions and assess deviations from optimality. The strategy presented is applicable to a host of combinatorial optimization problems. The assumptions of our model, along with computational experience, are discussed.     

Cost allocation rules for elastic single‐attribute situations

Many cooperative games, especially ones stemming from resource pooling in queueing or inventory systems, are based on situations in which each player is associated with a single attribute (a real number representing, say, a demand) and in which the cost to optimally serve any sum of attributes is described by an elastic function (which means that the per‐demand cost is non‐increasing in the total demand served). For this class of situations, we introduce and analyze several cost allocation rules: the proportional rule, the serial cost sharing rule, the benefit‐proportional rule, and various Shapley‐esque rules. We study their appeal with regard to fairness criteria such as coalitional rationality, benefit ordering, and relaxations thereof. After showing the impossibility of combining coalitional rationality and benefit ordering, we show for each of the cost allocation rules which fairness criteria it satisfies. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 271–286, 2017     

Economic Losses From a Fire in a Dense-Packed U.S. Spent Fuel Pool

In 2013, the staff of the U.S. Nuclear Regulatory Commission estimated the reduction of the off-site economic losses from a fire in a drained U.S. spent fuel pool if fuel that had cooled for more than five years were transferred to dry cask storage—an option it called “expedited transfer.” In this article, it is shown that the savings would be much higher than the NRC estimated. Savings increase to about $2 trillion if: losses beyond 50 miles are included; the land-contamination threshold for long-term population relocation is changed to that used for the Chernobyl and Fukushima accidents and recommended by the U.S. Environmental Protection Agency; and, based on the experience of Japan, decontamination of land areas to levels acceptable for population return is assumed to take at least four years. If expedited transfer were implemented, the off-site economic losses would be reduced by about 98%.     

Mean residual life of coherent systems consisting of multiple types of dependent components

Mean residual life is a useful dynamic characteristic to study reliability of a system. It has been widely considered in the literature not only for single unit systems but also for coherent systems. This article is concerned with the study of mean residual life for a coherent system that consists of multiple types of dependent components. In particular, the survival signature based generalized mixture representation is obtained for the survival function of a coherent system and it is used to evaluate the mean residual life function. Furthermore, two mean residual life functions under different conditional events on components’ lifetimes are also defined and studied.     

Waging the inchoate war: Defining,fighting, and second-guessing the ‘Long War’

Abstract

This article answers three questions: What is the nature of the Long War? How is progress (or lack thereof) to be assessed? Where is it likely to go next? An appreciation of Clausewitz shows that practical centers of gravity exist for the Long War, and that the conflict pivots upon the ability to persuasively link ideology to events via a strategic narrative. A close examination of an illustrative case study, the interaction between the US and the late Abu Musab al-Zarqawi in Iraq 2004 – 2006, shows that Al Qaeda has suffered a severe setback, but also that the nature of the war is set to shift yet again. Further tangible progress for the US requires waging the Long War as a global counterinsurgency based on a strategy of ‘selective identification’ (versus pure ‘disaggregation’) as well as an understanding of how to more effectively craft a strategic narrative.     

Explicit solution of partitioning problems over a 1‐dimensional parameter space

We consider a class of partitioning problems where the partitioned set is a finite set of real numbers and the objective function of a partition is a function of the vector whose coordinates are the sums of the elements in each part of the given partition (the number of such parts is assumed given). We obtain an explicit solution of such partitioning problem with polynomial complexity bounds. © John Wiley & Sons, Inc. Naval Research Logistics 47: 531–540, 2000     

Reconsidering minimum deterrence in South Asia: Indian responses to Pakistan’s tactical nuclear weapons

India’s nuclear doctrine and posture has traditionally been shaped by minimum deterrence logic. This logic includes assumptions that possession of only a small retaliatory nuclear force generates sufficient deterrent effect against adversaries, and accordingly that development of limited nuclear warfighting concepts and platforms are unnecessary for national security. The recent emergence of Pakistan’s Nasr tactical nuclear missile platform has generated pressures on Indian minimum deterrence. This article analyzes Indian official and strategic elite responses to the Nasr challenge, including policy recommendations and attendant implications. It argues that India should continue to adhere to minimum deterrence, which serves as the most appropriate concept for Indian nuclear policy and best supports broader foreign and security policy objectives. However, the form through which Indian minimum deterrence is delivered must be rethought in light of this new stage of regional nuclear competition.     

The South African Denuclearization Exemplar

ABSTRACT

South Africa's nuclear disarmament is a unique historical case, notable in part for the dramatic shift from deception to cooperation. The unprecedented transparency it demonstrated in order to convince the international community of the veracity of their disarmament is heralded as an exemplar for verifiable denuclearization. Less known is how this case affords insights into how a nuclear weapon program can be clandestinely hidden by the ambiguity provided by an otherwise completely legitimate, peaceful, nuclear energy program. Using a variety of open sources, including newly declassified internal South African and US government reports, it can be shown that South Africa employed a variety of deceptive tactics before it disarmed, and even for nearly two years after becoming a signatory to the Treaty on the Non-Proliferation of Nuclear Weapons. This article reviews that information to derive instructive lessons on the lengths that a nuclear proliferant state might go to conceal its true capabilities and intentions, and to thwart international discovery of the existence and full extent of an existing—or, in this case, a former—nuclear weapon program.