Operations Research articles from July 2002

Operations Research archives from July 2002

Implementing real-time optimization models: a case application from the motor carrier industry. (OR Practice).
July 1, 2002... Online models for real-time operations planning face a host of implementation issues that do not arise in more strategic arenas. We use the seemingly simple problem of assigning drivers to loads in the truckload motor carrier industry as an...

Optimizing military airlift.
July 1, 2002... We describe a large-scale linear programming model for optimizing strategic (intercontinental) airlift capability. The model routes cargo and passengers through a specified transportation network with a given fleet of aircraft subject to many...

A market-based approach to optimal resource allocation in integrated-services connection-oriented networks.
July 1, 2002... We present an approach to the admission control and resource allocation problem in connection-oriented networks that offer multiple services to users. Users' preferences are summarized by means of their utility functions, and each user is...

Spare-capacity assignment for line restoration using a single-facility type.
July 1, 2002... The network restoration problem is a specialized capacitated network design problem requiring the installation of spare capacity to fully restore disrupted network flows if any edge in a telecommunications network fails. We present a new...

A new interior-point boundary projection method for solving nonlinear groundwater pollution control problems.
July 1, 2002... A new interior-point algorithm for solving the groundwater-pollution-control design problem is presented. The algorithm requires that the objective function is differentiable in the interior region. For minimization problems with nonlinear...

Nonparametric efficiency estimation in stochastic environments.
July 1, 2002... This paper develops a new nonparametric model for efficiency estimation. In contrast to Data Envelopment Analysis (DEA), it does not impose debatable production assumptions like free disposability and convexity, and it does not assume that the...

On tightening the relaxations of miller-tucker-zemlin formulations for asymmetric traveling salesman problems.
July 1, 2002... This paper is concerned with applying the Reformulation-Linearization Technique (RLT) to derive tighter relaxations for the Asymmetric Traveling Salesman Problem (ATSP) formulation that is based on the Miller-Tucker-Zemlin (MTZ) subtour...

A bi-objective median location problem with a line barrier.
July 1, 2002... The multiple objective median problem (MOMP) involves locating a new facility with respect to a given set of existing facilities so that a vector of performance criteria is optimized. A variation of this problem is obtained if the existing...

Product cycling with uncertain yields: Analysis and application to the process industry.
July 1, 2002... We formulate the dynamic product-cycling problem with yield uncertainty and buffer limits to determine how much product to produce at what time to minimize total expected switching, production, inventory storage, and backorder costs. A...

A fluid heuristic for minimizing makespan in job shops.
July 1, 2002... We describe a simple online heuristic for scheduling job shops. We assume there is a fixed set of routes for the jobs, and many jobs, say N, on each route. The heuristic uses safety stocks and keeps the bottleneck machine busy at almost all...

Facets and reformulations for solving production planning with changeover costs.
July 1, 2002... We study a scheduling problem with changeover costs and capacity constraints. The problem is NP-complete, and combinatorial algorithms for solving it have not performed well. We identify a general class of facets that subsumes as special cases...

Asymptotic behavior of an allocation policy for revenue management.
July 1, 2002... Revenue management has become an important tool in the airline, hotel, and rental car industries. We describe asymptotic properties of revenue management policies derived from the solution of a deterministic optimization problem. Our primary...

A statistical test for nested radial DEA models.
July 1, 2002... Some problems in economics, operations research, and engineering may be approached by means of a pair of radial DEA models that are nested, i.e., that the set of constraints of one of them is included in that of the other. In this paper we have...

The access-control problem on capacitated FIFO networks with unique O-D paths is hard.
July 1, 2002... This paper is concerned with the performance of multicommodity capacitated networks in a deterministic but time-dependent environment. For a given time-dependent origin-destination table, this paper asks if it is easy to find a way of...

Online searching. (Technical Note).
July 1, 2002... In the recent paper (Jaillet and Stafford 2001), we consider the following search problem: Given m concurrent branches (each a copy of [R.sup.+]), a searcher, initially placed at the origin, has to find an "exit," which is at an unknown real...

On the optimality of the geometric sequences for the m ray search. (Technical Note).
July 1, 2002... The optimality of the (periodic) geometric trajectory {[epsilon][(m/m-1).sup.i]}, 0 [less than or equal to] i which has a first break point, easily follows from the minimax theorems. Corollary 1 (p. 117) of "Search Games" (note a...