INFORMS Journal on Computing articles from March 2001

INFORMS Journal on Computing archives from March 2001

Representations of the all_different predicate of constraint satisfaction in integer programming.
March 22, 2001... The use of predicates to state constraints in Constraint Satisfaction is explained. If, as an alternative, the traditional approach of Integer Programming (IP) is used, it is desirable to model these constraints so as to give as tight a linear...

The bounded cycle-cover problem.
March 22, 2001... We consider the bounded cycle-cover problem, which is to find a minimum cost cycle over of a two-connected graph such that no cycle in the cover contains more than a prescribed numbered of edges. This problem arises in the design of fiber-optic...

Scheduling batches with sequential job processing for two-machine flow and open shops.
March 22, 2001... In this paper, we study a problem of scheduling and batching on two machines in a flow-shop and open-shop environment. Each machine processes operations in batches, and the processing time of a batch is the sum of the processing times of the...

The online TSP against fair adversaries.
March 22, 2001... In the online traveling salesman problem, requests for visits to cities (points in a metric space) arrive online while the salesman is traveling. The salesman moves at no more than unit speed and starts and ends his work at a designated origin....

Properties of batched quadratic-form variance parameter estimators for simulations.
March 22, 2001... We examine the practice of batching of certain quadratic-form estimators for the variance parameter of a stochastic process. The class of batched quadratic-form estimators includes, among others, the standardized time series (STS) weighted area...

Non-approximability results for scheduling problems with minsum criteria.
March 22, 2001... We provide several non-approximability results for deterministic scheduling problems whose objective is to minimize the total job completion time. Unless P = NP, none of the problems under consideration can be approximated in polynomial time...

Addendum to "presolve analysis of linear programs prior to applying an interior point method".
March 22, 2001... In this note we point out that the assumptions of Propositions 1 and 2 in Gondzio (1997) are not sufficiently restrictive. We give an example that demonstrates the lack of precision in these propositions and discuss the necessary modifications...