Solving a selected class of location problems by exploiting problem structure: A decomposition approach

For many combinatorial optimization problems that are NP-hard, a number of special cases exist that can be solved in polynomial time. This paper addresses the issue of solving one such problem, the well-known m-median problem with mutual communication (MMMC), by exploiting polynomially solvable special cases of the problem. For MMMC, a dependency graph is defined that characterizes the structure of the interactions between decision variables. A Lagrangian decomposition scheme is proposed that partitions the problem into two or more subproblems, each having the same structure as the original problem, but with simpler dependency graphs. The dual problems are solved using subgradient or multiplier adjustment methods. An efficient method of adjusting the multiplier values is given. Computational results are reported that show the method to be quite effective. In addition, applications of the approach to other difficult location problems is discussed. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 791–815, 1998     

A critical look at the U.S. deceased‐donor organ procurement and utilization system

The U.S. system for procuring and utilizing deceased‐donor organs for transplantation has been studied and written about in many articles. The purpose of this paper is to examine the interactions between the elements that comprise this system, and point out improvement opportunities that may be affected through operations research/management techniques. The authors demonstrate the need for developing data‐driven and analytic tools. In fact, data is used to generate hypotheses and support claims throughout the paper. The paper also points out the need to fully leverage data that is available to researchers, and to seek data that is currently not deposited in a centralized archive.     

The selection allocation problem

The Selection Allocation Problem (SAP) is a single period decision problem which involves selecting profit‐maximizing (or cost‐minimizing) activities from various distinct groups, and determining the volume of those activities. The activities in each group are selected subject to the availability of that group's resource, which is provided by either pooling or blending raw inputs from several potential sources. Imbedded in the decision process is the additional task of determining how much raw input is to be allocated to each group to form the resource for that group. Instances of this problem can be found in many different areas, such as in tool selection for flexible manufacturing systems, facility location, and funding for social services. Our goal in this paper is to identify and exploit special structures in the (SAP) and use those structures to develop an efficient solution procedure. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 707–725, 1999     

The effect of process adjustment error on X̄ chart design

The existing literature on economic design of X̄ process control charts generally assumes perfect process adjustment, such that the process mean is returned to an exactly centered “in control” state following any real or false alarm control chart signal. This paper presents a model which demonstrates the effects of imperfect process adjustment on the economically designed control chart parameters. The model demonstrates that the optimal control limit width depends fundamentally on the precision with which the process can be adjusted. The greater the process adjustment error, all else constant, the wider will be the optimal control limits, in order to alleviate the potential for process overcontrol and tampering effects. By endogenously modeling these effects, the new model helps to rectify the problem of poor statistical properties for which the economic design approach has been criticized. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 597–612, 1999     

The applicability of acceptance sampling with respect to process stability and control

This article examines the applicability of acceptance sampling and the effectiveness of Deming's kp rule in relation to the degree of process stability achieved through statistical process control techniques. A discrete-event simulation model is used to characterize the correlation between the number of defective units in a randomly drawn sample versus in the remainder of a lot, in response to a number of system and control chart parameters. The model reveals that such correlation is typically present when special causes of variation affect the production process from time to time, even though the process is tightly monitored through statistical process control. Comparison of these results to an analogous mixed binomial scenario reveals that the mixed binomial model overstates the correlation in question if the state of the process is not necessarily constant during lot production. A generalization of the kp analysis is presented that incorporates the possibility of dependence between a sample and the unsampled portion of the lot. This analysis demonstrates that acceptance sampling is generally ineffective for lots generated by a process subject to statistical process control, despite the fact that the number of defectives in the sample and in the remainder of the lot are not strictly independent. © 1994 John Wiley & Sons, Inc.     

Reserve forces and the transformation of British military organisation: soldiers,citizens and society

In recent years, there has been a sharp growth in political and sociological interest in the British military. Set against the backdrop of the armed forces’ increasing presence in everyday life, alongside the organizations’ ongoing restructuring, the current paper focuses on the MoD’s problematic attempts to recruit 30,000 reservists by 2020; what has become known as the Future Reserves 2020 programme (FR2020). We argue that these changes are driven in part by the need to cut costs in defence. However, we also suggest that they are a reflection of the changing nature of modern military organisation, and the manner in which armed forces engage with the societies of which they are a part, and with the citizens that make up that society. We locate FR2020 programme in the context of a wider narrative about the changing nature of military organisation in contemporary western democracies, identifying structural, circumstantial and normative reasons for change. We also examine the specific challenges of implementing FR2020 in practice, including issues of recruitment and retention, integration and support, and relations with families and employers, drawing on the experience of comparator countries to do so. We conclude by considering the implications of these changes, both for the future of UK armed forces, and for the evolving nature of military-society relations in Britain.     

Ireland: rebellion and counter-insurgency, 1848–1867

ABSTRACT

The period 1848 to 1867 witnessed what could be regarded as a very small-scale insurgency campaign in Ireland, waged by agrarian groups; the Whiteboys and Ribbonmen. 1848 and 1867 witnessed rebellions by the Young Irelanders and Fenians, which proved to be small-scale and of short duration but the British government had prepared for a nationwide counter-insurgency campaign. The government relied heavily on the militarised Irish Constabulary but in 1848 and 1867 troops were used in large numbers and there were concerns about how they could be best concentrated to meet the envisaged threat.     

The ‘first’ surge: the repulse of the Easter Invasion in South Vietnam, 1972 – implications for Iraq and Afghanistan

In a military intervention, do surges work? I compare the failed ‘surge’ in Vietnam, the repulse of the Easter Invasion in 1972, as a means of assessing the more ambiguous surges in Iraq and Afghanistan. I identify four features of a surge for this analysis: the military dimensions and strategy of the surging forces, the military capabilities of the host forces, the political vitality and will of the host country, and the political commitment in the domestic politics of the intervener. I find that the last feature is the most critical; and, in all three surges, the American political commitment was lacking.