A class of Bayes-optimal two-stage screens

Items are characterized by a set of attributes (T) and a collection of covariates (X) associated with those attributes. We wish to screen for acceptable items (T ∈ C_T), but T is expensive to measure. We envisage a two-stage screen in which observation of X_ is used as a filter at the first stage to sentence most items. The second stage involves the observation of T for those items for which the first stage is indecisive. We adopt a Bayes decision-theoretic approach to the development of optimal two-stage screens within a general framework for costs and stochastic structure. We also consider the important question of how much screens need to be modified in the light of resource limitations that bound the proportion of items that can be passed to the second stage. © 1996 John Wiley & Sons, Inc.     

Gittins-index heuristics for research planning

The classical work of Gittins, which resulted in the celebrated index result, had applications to research planning as an important part of its motivation. However, research planning problems often have features that are not accommodated within Gittins's original framework. These include precedence constraints on the task set, influence between tasks, stopping or investment options and routes to success in which some tasks do not feature. We consider three classes of Markovian decision models for research planning, each of which has all of these features. Gittins-index heuristics are proposed and are assessed both analytically and computationally. They perform impressively. © 1995 John Wiley & Sons, Inc.     

Book Reviews

Strategic Geography. By Hugh Faringdon. Routledge, London (1989), ISBN 0-415-00980-4, £40.00

Field Artillery and Firepower. By J. B. A. Bailey. The Military Press, Oxford (1989), ISBN 0-85066-810-7, £25.00 (hardback), ISBN 0-85066-811-5, £14.50 (paperback)

U.S.-Soviet Security Cooperation. Edited by Alexander L. George, Philip J. Farley and Alexander Dallin. Oxford University Press, New York (1988), ISBN 0-19-505397-4, £30.00 (hardback), $19.95 (paperback)

Non-production by Industry of Chemical-warfare Agents: Technical Verification under a Chemical Weapons Convention. Edited by S. J. Lundin. SIPRI/Oxford University Press, Oxford (1988), ISBN 0-19-829129-9, £19.50

Ireland's Terrorist Trauma: Interdisciplinary Perspectives. Edited by Alan O'Day and Yonah Alexander. Harvester Wheatsheaf, Hemel Hempstead (1989), ISBN 7450-049003, £27.50 ($48.65)

Pilots and Rebels: the Use of Aircraft in Unconventional Warfare 1918-1988. By P. A. Towle. Brassey's (UK), London (1989), ISBN 0-08-036712-7, £29.95 ($53.95)     

A model for critical crack size estimation in fatigue failure of gun barrels

With repeated firing, fatigue cracks are produced in a gun barrel, and the barrel is no longer useful when a crack reaches a critical size. The initial crack size and the critical crack size, as well as the number of firings producing the critical crack size, may be considered as random variables. Assuming a proportional damage model for crack growth, a method for estimating the critical crack size distribution is presented. From these results, an estimate of the barrel life, or the residual barrel life once a crack of a given size is measured, can be obtained.     

The road not taken: Conflict termination and guerrillaism in the American Civil War

Irrespective our views on the rationality of our opponent's continuing to conduct operations against us, unless utterly extirpated, he retains a vote on when and how conflict will end. This is because war is about power — compelling another actor to do something he would not otherwise do, or to cease doing something he would otherwise prefer to do. In planning for conflict termination we should account for the peculiarities of opponents who may decide not to quit when we have beat them fair and square. We do not desire that they cease conventional fighting, but that they cease fighting altogether.     

Encircled by enemies: Stalin's Perceptions of the capitalist world, 1918 – 1941

The article examines Stalin's intelligence on the capitalist world, including materials from military archives, diplomatic archives, and Stalin's private papers. It explores how these materials were collected, interpreted and shaped by Stalin's prejudices. It concludes that, from the end of the Civil War to the Nazi invasion, Stalin and the Soviet leadership believed that the Soviet Union was under a nearly constant threat of invasion from shifting coalitions of capitalist powers. No such threat existed until the late 1930s, but Stalin's perceptions have important implications for our understanding of Soviet foreign and domestic politics in the interwar period.     

The RAF staff college and the evolution of British strategic bombing policy, 1922–1929

This article borrows from the work of Clausewitz to posit two general approaches to the pursuit of limitation in war, one being political and the other technical. The political approach seeks to control escalation via consensual arrangements with the adversary, while the technical approach seeks to forestall escalation by peremptorily destroying the enemy's military capability. It is argued that the 'Revolution in Military Affairs' (RMA) instantiates the second, technical, approach to war limitation. By exploiting advanced technology, the US armed forces hope to limit the costs of war by defeating their adversaries in a rapid, decisive manner. The problems associated with this approach are discussed in relation to the nature of the conflicts that the US is likely to face in the foreseeable future. The article concludes by suggesting that such conflicts will require that more attention be paid to the political sources of limitation in war.     

Debt Burden,Military Spending And Growth In Sub-Saharan Africa: A Dynamic Panel Data Analysis

This article empirically explores the relationship between military expenditure, external debts and economic performance in the economies of sub-Saharan Africa using a sample of 25 countries from 1988–2007. In investigating the defence–external debt nexus, we employ three advanced panel techniques of fully modified OLS (FMOLS), Dynamic OLS (DOLS) and dynamic fixed effect (DFE) to estimate our model. We observe that military expenditure has a positive and significant impact on external debt in African countries. Real GDP affects the total debt stock of African countries with a negative relationship. Our empirical results based on long-run elasticities show that a 1% rise in national output leads to a decline in external debt by 1.52%, on average. Policy-wise, the study suggests that African countries need to strengthen areas of fiscal responsibility and pursue models that encourage rational spending, particularly reductions in military expenditure.