Operations Research articles from July 2005

Operations Research archives from July 2005

In this issue.
July 1, 2005... Designing a Packet-Based Telecommunications Network Packet-based networks are rapidly replacing the traditional circuit-switched telecommunications networks. The new services carried by these networks differ from voice communications in...

Sizing backbone Internet links.
July 1, 2005... One of the distinguishing features of a backbone link is that it is designed to carry traffic from a large number of end users. This results in a Normal distribution for the number of bytes or packets that arrive in a fixed-length time...

Portfolio optimization with factors, scenarios, and realistic short positions (1).
July 1, 2005... This paper presents fast algorithms for calculating mean-variance efficient frontiers when the investor can sell securities short as well as buy long, and when a factor and/or scenario model of covariance is assumed. Currently, fast algorithms...

System-optimal routing of traffic flows with user constraints in networks with congestion.
July 1, 2005... The design of route guidance systems faces a well-known dilemma. The approach that theoretically yields the system-optimal traffic pattern may discriminate against some users in favor of others. Proposed alternate models, however, do not...

Capacity management in rental businesses with two customer bases.
July 1, 2005... We consider the allocation of capacity in a system in which rental equipment is accessed by two classes of customers. We formulate the problem as a continuous-time analogue of the one-shot allocation problems found in the more traditional...

Dynamic aggregation of set-partitioning constraints in column generation.
July 1, 2005... Column generation is often used to solve problems involving set-partitioning constraints, such as vehicle-routing and crew-scheduling problems. When these constraints are in large numbers and the columns have on average more than 8-12 nonzero...

Generation capacity expansion in imperfectly competitive restructured electricity markets.
July 1, 2005... We consider three models of investments in generation capacity in restructured electricity systems that differ with respect to their underlying economic assumptions. The first model assumes a perfect, competitive equilibrium. It is very similar...

Production control policies in supply chains with selective-information sharing.
July 1, 2005... We consider a supply chain consisting of one manufacturer (capacitated supplier) and two retailers. We characterize the manufacturer's optimal production policy under selective-information sharing, in which the manufacturer receives demand and...

Recovering cyclic schedules using dynamic produce-up-to policies.
July 1, 2005... We consider facilities that follow a cyclic schedule to replenish the inventory of a set of items through production by a shared resource. We introduce a dynamic produce-up-to policy that recovers the target cyclic schedule after a single...

Rendezvous-evasion search in two boxes.
July 1, 2005... An agent (who may or may not want to be found) is located in one of two boxes. At time 0 suppose that he is in box B. With probability p he wishes to be found, in which case he has been asked to stay in box B. With probability 1 - p he tries to...

Staggering periodic replenishment in multivendor JIT environments.(just-in-time )
July 1, 2005... The delivery scheduling problem studied in this paper was motivated by the operation in a large personal computer assembly plant, which was using multisourcing for some of its materials. The company's objective was to design a delivery schedule...

Lot sizing with inventory bounds and fixed costs: polyhedral study and computation.
July 1, 2005... We investigate the polyhedral structure of the lot-sizing problem with inventory bounds. We consider two models, one with linear cost on inventory, the other with linear and fixed costs on inventory. For both models, we identify facet-defining...

A note on the optimal EOQ for announced price increases in the infinite horizon.(TECHNICAL NOTE)(economic order quantity)
July 1, 2005... Huang et al. (2003) used the Cesaro limit of a savings function to determine the optimal special order in an EOQ model with single announced price increases over an infinite horizon. In this note, we point out that the savings function is not...

A note on closure properties of failure rate distributions.(TECHNICAL NOTE)
July 1, 2005... Increasing generalized failure rate (IGFR) distributions were introduced as a tool in the study of contracting mechanisms in supply chains. In this note, we compare and contrast the closure--and the lack thereof--of IGFR and increasing failure...

Erratum to "the three-dimensional bin packing problem": robot-packable and orthogonal variants of packing problems.(ERRATUM)
July 1, 2005... In the three-dimensional bin packing problem the task is to orthogonally pack a given set of rectangular items into a minimum number of three-dimensional rectangular bins. We give a characterization of the algorithm proposed by Martello et al....