Operations Research articles from July 2003

Operations Research archives from July 2003

Broadcast scheduling for mobile advertising.(OR Practice)
July 1, 2003... We describe a broadcast scheduling system developed for a precision marketing firm specialized in location-sensitive permission-based mobile advertising using SMS (Short Message Service) text messaging. Text messages containing advertisements...

An empirical study of service differentiation for weapon system service parts.
July 1, 2003... The question of how to effectively manage items with heterogeneous attributes and differing service requirements has become increasingly important to supply chains that support the delivery of after-sales service. However, there has been little...

How multiserver queues scale with growing congestion-dependent demand.
July 1, 2003... We investigate how performance scales in the standard M/M/n queue in the presence of growing congestion-dependent customer demand. We scale the queue by letting the potential (congestion-free) arrival rate be proportional to the number of...

Worst-case value-at-risk and robust portfolio optimization: a conic programming approach.
July 1, 2003... Classical formulations of the portfolio optimization problem, such as mean-variance or Value-at-Risk (VaR) approaches, can result in a portfolio extremely sensitive to errors in the data, such as mean and covariance matrix of the returns. In...

Tight MIP formulations for multi-item discrete lot-sizing problems.
July 1, 2003... This paper discusses mixed-integer programming formulations of variants of the discrete lot-sizing problem. Our approach is to identify simple mixed-integer sets within these models and to apply tight formulations for these sets. This allows us...

Supply chain scheduling: batching and delivery.
July 1, 2003... Although the supply chain management literature is extensive, the benefits and challenges of coordinated decision making within supply chain scheduling models have not been studied. We consider a variety of scheduling, batching, and delivery...

Operations and shipment scheduling of a batch on a flexible machine.
July 1, 2003... We consider processing and shipment scheduling of a batch of size M jobs on a flexible (multifunctional) machine. All jobs in the batch require the same sequence of N operations on the machine. Costs are incurred in the forms of holding costs...

Market offering strategies for hydroelectric generators.
July 1, 2003... This paper considers the problem of offering electricity produced by a series of hydroelectric reservoirs to a pool-type central market. The market model is a simplified version of the New Zealand wholesale electricity market, with prices...

A problem of forest harvesting and road building solved through model strengthening and Lagrangean relaxation.
July 1, 2003... We consider a problem of forest planning on pine plantations over a two to five year horizon. Basic decisions concern the areas to harvest in each period, the amount of timber to produce to satisfy aggregate demands for log exports, sawmills...

Enhanced model formulations for optimal facility layout.
July 1, 2003... This paper presents an improved mixed-integer programming (MIP) model and effective solution strategies for the facility layout problem and is motivated by the work of Meller et al. (1999). This class of problems seeks to determine a least-cost...

Admission control with incomplete information of a queueing system.
July 1, 2003... We consider a multiple-server loss model where customers arrive at a gatekeeper according to a Poisson process. A cost c is incurred if a new arrival is blocked from entering the system by the gatekeeper, while a larger cost K is incurred if an...

Cycle-based neighbourhoods for fixed-charge capacitated multicommodity network design.
July 1, 2003... We propose new cycle-based neighbourhood structures for metaheuristics aimed at the fixed-charge capacitated multicommodity network design formulation. The neighbourhood defines moves that explicitly take into account the impact on the total...

Inventory cost effect of consolidating several one-warehouse multiretailer systems.(Technical note)
July 1, 2003... Consolidation of warehouses is a new trend in global logistics management, and the reduction in order processing and inventory costs is often cited as one of the main motivations. In this note we show that when retailers face constant demand...