Single machine sequencing with random processing times and random due-dates

A single machine scheduling problem in which both the processing times and due-dates of the jobs awaiting servicing are random variables is analyzed. It is proved that the properties of the shortest processing time rule and the due-date rule which are known for the deterministic situation also hold in the probabilistic environment when they are suitably, and reasonably, refined for this context.     

A two-echelon multi-station inventory model for navy applications

The two inventory echelons under consideration are the depot, D, and k tender ships E₁, …, E_k. The tender ships supply the demand for certain parts of operational boats (the customers). The statistical model assumes that the total monthly demands at the k tenders are stationary independent Poisson random variables, with unknown means λ₁, …, λ_k. The stock levels on the tenders, at the heginning of each month, can be adjusted either by ordering more units from the depot, or by shipping bach to the depot an excess stock. There is no traffic of stock between tenders which is not via the depot. The lead time from the depot to the tenders is at most 1 month. The lead time for orders of the depot from the manufacturer is L months. The loss function due to erroneous decision js comprised of linear functions of the extra monthly stocks, and linear functions of shortages at the tenders and at the depot over the N months. A Bayes sequential decision process is set up for the optimal adjustment levels and orders of the two echelons. The Dynamic Programming recursive functions are given for a planning horizon of N months.     

Resource allocation for transportation

A linear programming formulation is described that will permit the optimal assignment of transportation resources (vehicles) and movement requirements to a network consisting of a set of designated origins, ports of embarkation, enroute bases, ports of debarkation, and destinations to achieve a prescribed schedule of arrivals.     

Vertically restrictive pricing in supply chains with price‐dependent demand

We examine the behavior of a manufacturer and a retailer in a decentralized supply chain under price‐dependent, stochastic demand. We model a retail fixed markup (RFM) policy, which can arise as a form of vertically restrictive pricing in a supply chain, and we examine its effect on supply chain performance. We prove the existence of the optimal pricing and replenishment policies when demand has a linear additive form and the distribution of the uncertainty component has a nondecreasing failure rate. We numerically compare the relative performance of RFM to a price‐only contract and we find that RFM results in greater profit for the supply chain than the price‐only contract in a variety of scenarios. We find that RFM can lead to Pareto‐improving solutions where both the supplier and the retailer earn more profit than under a price‐only contract. Finally, we compare RFM to a buyback contract and explore the implications of allowing the fixed markup parameter to be endogenous to the model. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006.     

Restricted planar location problems and applications

Facility location problems in the plane are among the most widely used tools of Mathematical Programming in modeling real-world problems. In many of these problems restrictions have to be considered which correspond to regions in which a placement of new locations is forbidden. We consider center and median problems where the forbidden set is a union of pairwise disjoint convex sets. As applications we discuss the assembly of printed circuit boards, obnoxious facility location and the location of emergency facilities. © 1995 John Wiley & Sons, Inc.     

“Disarmament Market” Effects of Information Disclosures

In yet another wave of discussion on nuclear disarmament among political scientists and practitioners, one of the topical issues concerns the problem of transparency, its mechanisms, costs, and benefits. Numerous—though often abstract—calls for greater transparency of nuclear arsenals and postures when promoting the idea of nuclear disarmament, however, do not give a clear rationale for states possessing nuclear weapons to pursue greater transparency. Meanwhile, many other research fields—such as economics and psychology—attempt to address problems related to the lack of exact information on the counterpart's activities and intentions. Economics offers one probable analog for the transparency problem: the issue of information asymmetry and its consequences. This article is an attempt to apply the classical model of a market with information asymmetry to the analysis of the transparency problem within the nuclear disarmament process. Such an approach could help pave the way for closer cooperation between economic and political scientists in the nuclear disarmament field.     

Military spending and economic growth in South Africa

This paper undertakes an empirical analysis of the economic effects of military spending on the South African economy. It estimates a neo‐classical model common in the literature at the level of the macroeconomy and at the level of the manufacturing sector. An attempt is made to improve upon the model by allowing the data to determine the dynamic structure of the model through an ARDL procedure. No significant impact of military spending is found in aggregate, but there is a significant negative impact for the manufacturing sector. This suggests that the cuts in domestic military procurement that have occurred since 1989 could lead to improved economic performance in South Africa through their impact on the manufacturing sector.     

The impact of arms production on the South African manufacturing industry

The 1977 UN arms embargo was one of the main factors which led South Africa to establish a largely self sufficient import‐substituting arms industry capable of meeting the apartheid state's demand for sophisticated weaponry. While macroeconomic studies suggest that high military spending had a damaging effect on economic growth, no studies have investigated the disaggregated impact of military expenditure on industrial development. This paper applies panel data methods to the Industrial Development Corporation's Sectoral Database in order to analyse the level effects of military spending.