Queueing-location problems on the plane

In this article we present a queueing-location problem where a location of a service station has to be determined. The two main results of this article are a convexity proof for general distances and a theorem that limits the area in the plane where the solution can lie. We also propose some solution procedures.     

New worst-case results for the bin-packing problem

In this note we consider the familiar bin-packing problem and provide new worst-case results for a number of classical heuristics. We show that the first-fit and best-fit heuristics have an absolute performance ratio of no more than 1.75, and first-fit decreasing and best-fit decreasing heuristics have an absolute performance ratio of 1.5. The latter is the best possible absolute performance ratio for the bin-packing problem, unless P = NP. © 1994 John Wiley & Sons, Inc.     

Estimation and prediction in a semi-markov model for evasive vehicle movement along a fixed path

In Turner and Holmes [8] a model for evasive vehicle movement along a fixed track is developed within the mathematical framework of a two-state semi-Markov process. They derive a number of analytical properties of the model. In this article we address problems concerning the estimation of parameters in the model and the construction of data-based prediction equations.     

Honour,Comradeship and Betrayal: Lord Capel’s Sword

The sword which is the subject of this article and which will be referred to as the Capel sword, is a fine example of what has become known as an Irish basket-hilt. Whilst there are other examples in existence, what makes this sword unique and particularly important is the fact that it is known to have been owned by two important Royalist military leaders, Lord Arthur Capel and Sir John Owen. These two extraordinary men came from different backgrounds but their fate was linked through circumstances beyond their control. The story this sword tells is one of comradeship, loyalty, total belief in a cause, betrayal and ultimate sacrifice.     

To Protect and Serve: Civilian Policing and the United Nations Mission in Kosovo

Since the end of the Cold War the process of nation building has become a priority in the attempt to maintain world order and security in the wake of the instability and devastation wrought by failed and war-torn states. The proliferation of nation-building missions has led to their diversification and the need to marshal a vast array of resources in order to attain substantial levels of success. This article deals with a new and important component of peacekeeping and nation-building missions, that of civilian policing. The article outlines the goals of using civilian police officers in nation-building missions and discusses a variety of problems (pragmatic, legal, and cultural) that policing may introduce to such missions. This discussion is focused around the civilian policing component of the United Nations Mission in Kosovo. It delineates the successes and hardships so far experienced during the mission in Kosovo and explores the insights that the mission may provide for similar projects in the future.     

Approximating nonstationary two-priority non-preemptive queueing systems

An approximation for analyzing transient and nonstationary two-priority non-preemptive queueing systems is presented. This system has a three-dimensional state space, and through use of state-space partitioning in conjunction with use of conditional surrogate distributions with constant parameters an approximation is designed. Regardless of system capacity K, the approximation requires the numerical solution of only ten differential equations, compared to the K² + K+1 Kolmogorov-forward equations required for the classic solution. Time-dependent approximations of the mean number of entities of type i and of the probability of a type-i entity being in service are obtained. Empirical test results over a wide range of systems indicate the approximation is quite accurate.     

An (s,S) inventory system with rest periods to the server

We study the (s,S) inventory system in which the server takes a rest when the level of the inventory is zero. The demands are assumed to occur for one unit at a time. The interoccurrence times between successive demands, the lead times, and the rest times are assumed to follow general distributions which are mutually independent. Using renewal and convolution techniques we obtain the state transition probabilities.     

Resequencing with parallel queues to minimize the maximum number of items in the overflow area

This article treats an elementary optimization problem, where an inbound stream of successive items is to be resequenced with the help of multiple parallel queues in order to restore an intended target sequence. Whenever early items block the one item to be currently released into the target sequence, they are withdrawn from their queue and intermediately stored in an overflow area until their actual release is reached. We aim to minimize the maximum number of items simultaneously stored in the overflow area during the complete resequencing process. We met this problem in industry practice at a large German automobile producer, who has to resequence containers with car seats prior to the assembly process. We formalize the resulting resequencing problem and provide suited exact and heuristic solution algorithms. In our computational study, we also address managerial aspects such as how to properly avoid the negative effects of sequence alterations. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 401–415, 2016     

The cyber conceptual framework for developing military doctrine

Militaries rely on secure communications. Despite the permeation of cyber-systems throughout the operational environment, there is little readily available doctrine on cyber-warfare. Doctrine that does exist has not been coherently integrated. This paper introduces a Cyber Conceptual Framework, consisting of five questions pertinent to the future use of cyberspace. The authors enunciate a definition of cyberspace, expand on existing military doctrine to reject the conceptualisation of cyberspace as a domain, define cyber-conflict, define cyber-attack and describe the four components and five levels of a cyber-attack. This work develops a common framework from available doctrine and a lexicon for future discussion.