Mixture selection for maximal stochastic performance

Methodology for the optimal selection of a mixture of components for the attainment of a required performance level is developed. This accommodates both cost and stochastic variation and is applied to gasoline blending. © 1994 John Wiley & Sons, Inc.     

Inequalities involving the lifetime of series and parallel systems

Let {Xⁱ} be independent HNBUE (Harmonic New Better Than Used in Expectation) random variables and let {Yⁱ} be independent exponential random variables such that E{Xⁱ}=E{Yⁱ} It is shown that \documentclass{article}\pagestyle{empty}\begin{document}$ E\left[{u\left({\mathop {\min \,X_i}\limits_{l \le i \le n}} \right)} \right] \ge E\left[{u\left({\mathop {\min \,Y_i}\limits_{l \le i \le n}} \right)} \right] $\end{document} for all increasing and concave u. This generalizes a result of Kubat. When comparing two series systems with components of equal cost, one with lifetimes {Xⁱ} and the other with lifetimes {Yⁱ}, it is shown that a risk-averse decision-maker will prefer the HNBUE system. Similar results are obtained for parallel systems.     

Covert Canucks: Intelligence Gathering and the 1924 Voyage of HMCS Thiepval in the North Pacific Ocean

In 1924, HMCS Thiepval provided logistical support to a British attempt to circumnavigate the world by air. But the ship had another secret mission. Concerned America and Japan were fortifying their north Pacific possessions in violation of the 1922 Washington Treaty, and fearing war might be inevitable, the Canadian navy sent the Thiepval to covertly spy upon American and Japanese facilities. No cheating was discovered, but in the longer run, Canadian concerns about hostilities in the north Pacific were ‘on the mark’ correct.     

Reconstruction,the Long Tail and Decentralisation: An Application to Iraq and Afghanistan

In this paper, we examine the current state of knowledge in the economics literature on the conduct of reconstruction activities in Iraq and Afghanistan. As stabilisation and reconstruction missions grow in importance for units deployed to these regions, it becomes more important to understand what activities can promote economic growth at the local level. While military operations focus on interdicting the insurgency, successful counter-insurgency campaigns have typically addressed the conditions conducive to the insurgency. Mitigating the incentives for individuals to participate in an insurgency is imperative. Well-crafted and timed reconstruction activities can, we argue, attenuate these incentives.     

Managerial inventory formulations with stockout objectives and fiscal constraints

Most inventory formulations seek to minimize the sum of ordering costs, holding costs, and stockout costs: however, management often directs inventory policy by specifying a maximum investment level and/or a purchasing budget constraint. Within these limitations, they expect lower level managers to optimize some level of customer satisfaction, such as minimum stockouts or minimum shortages. The author has developed several cases of these “managerial” inventory formulations and has presented some computational results.     

Optimal renewal policies for complex systems

Most maintenance and replacement models for industrial equipment have been developed for independent single-component machines. Most equipment, however, consists of multiple components. Also, when the maintenance crew services several machines, the maintenance policy for each machine is not independent of the states of the other machines. In this paper, two dynamic programming replacement models are presented. The first is used to determine the optimal replacement policy for multi-component equipment. The second is used to determine the optimal replacement policy for a multi-machine system which uses one replacement crew to service several machines. In addition, an approach is suggested for developing an efficient replacement policy for a multi-component, multi-machine system.