Optimal production growth for the machine loading problem

This paper investigates a production growth logistics system for the machine loading problem (generalized transportation model), with a linear cost structure and minimum levels on total machine hours (resources) and product types (demands). An algorithm is provided for tracing the production growth path of this system, viz. in determining the optimal machine loading schedule of machines for product types, when the volumes of (i) total machine hours, and (ii) the total amount of product types are increased either individually for each total or simultaneously for both. Extensions of this methodology, when (i) the costs of production are convex and piecewise linear, and (ii) when the costs are nonconvex due to quantity discounts, and (iii) when there are upper bounds for productions are also discussed. Finally, a “goal-programming” production growth model where the specified demands are treated as just goals and not as absolute quantities to be satisfied is also considered.     

A note on splitting the bump in an elimination factorization

This exposition presents a method for incorporating a technique known as “splitting the bump” within an elimination form reinversion algorithm. This procedure is designed to reduce fill-in during reinversion and should improve the efficiency of linear programming systems which already use the superior elimination form of the inverse.     

A methodology for studying the dynamics of extended logistic systems

An extended logistic system is a well-defined configuration of equipment, modules, inventories, and repair and replacement facilities modeling a complex, repairable system with on-going repair. The design of such systems has been based largely on the static tools of inventory theory and reliability theory, i.e., on steady-state distributions and on associated means and variances. Such static tools suppress the scale of real lime and ignore system persistence time in up-states and persistence time in down-states. A reasonably simple dynamic methodology is presented, focusing on system failure time as a more meaningful objective function for system-design tradeoff studies. In the presence of good reliability, it is shown that different candidates for system failure time effectively merge to yield an unambiguous, single system failure time. Examples illustrating the importance of dynamic information for system design are given.     

The US NATO and military burden sharing: post-Cold War accomplishments and future prospects

NATO burden sharing has become an especially timely issue in the past several years as a result of a number of factors, including Russian annexation of Crimea and destabilization of eastern Ukraine in 2014. This article argues that alliance unity among the great democracies of Europe and North America is indispensable to peace and stability on the Eurasian continent. A fractured NATO, and especially, a large divide in purposes or commitments as between the United States and its European security partners, invites aggression and the possibility of inadvertent escalation. Past successes and failures in US-involved multinational peace and stability operations, within and outside of Europe, show that mission accomplishment requires give and take, including the occasional acceptance of unequal costs and benefits among the members, in order to achieve peace and security objectives.     

Flintlock brass fittings from the 19th-century Akko 1 shipwreck,Israel

The Akko 1 shipwreck is the remains of a 26-metre-long Egyptian armed vessel or auxiliary naval brig built at the beginning of the 19th century. Remains of six flintlock muskets were retrieved from the shipwreck, and characterised by various metallurgical methods. The research aimed to study the composition and microstructure of the musket fittings and their manufacturing processes, and if possible, to determine the date and origin of the raw materials. The lead isotope analysis of the fittings suggests that their raw material originated in Great Britain. Based on their typology and composition, the fittings were made in Great Britain of brass alloy and manufactured by casting, probably at the same workshop; and the staple was manufactured by casting and drawing. Considering the zinc content, combined with the manufacturing techniques, the fittings were manufactured between the latter part of the 18th and the early 19th centuries, which might indicate that they were purchased in the course of 19th century weapons trade to be used on board the Egyptian ship.     

A generalized inspection game

The paper addresses the problem of a patrol trying to stop smugglers who are attempting to ship a cargo of perishable contraband across a strait in one of M time units. The situation was modeled as a two-person zero-sum game of exhaustion by Thomas and Nisgav and this article extends their results. The game has many characteristics in common with the Inspection Game in Owen's book on Game Theory; this Inspection Game is generalized and the relations between the two games are discussed.     

Application of the stein-chen method for bounds and limit theorems in the reliability of coherent structures

The Stein-Chen method for establishing Poisson convergence is used to approximate the reliability of coherent systems with exponential-type distribution functions. These bounds lead to quite general limit theorems for the lifetime distribution of large coherent systems. © 1993 John Wiley & Sons, Inc.     

Optimal maintenance and replacement policy for a deteriorating system with increased mean downtime

The problem of imperfect preventive maintenance (pm) and replacement schedule for a system which works below a specified failure rate is studied. For a given planning period, the optimal schedule for replacements to minimize the total cost is obtained. This article presents a branching algorithm with effective dominance rules to obtain the optimal schedule. Numerical illustration and computational experience are also presented.     

The value of observing the condition of a deteriorating machine

We examine a small lot production setting in which a machine may go out of control and begin producing defective units. Traditionally, managers have had to rely upon observations of the quality of the output to determine whether the machine is in or out of control. However, with advances in technology such as vibration analysis, it is increasingly possible to obtain much more accurate information about the state of the machine. In this paper, we model and analyze a deteriorating machine in order to gain insight into the conditions under which investments in such technology are most beneficial. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 790–808, 1999