Showing papers in "Operations Research Letters in 1989"

TL;DR: An efficient probabilistic set covering heuristic is presented that provides the best known solutions to all other instances attempted to solve set covering problems that arise from Steiner triple systems.

TL;DR: In this paper, the authors investigated the computational complexity of the problem for all commonly studied product structures, i.e., the single item, the serial system, the assembly system, one-warehouse-N-retailer system, distribution system, joint replenishment system, and the general production-distribution system.

TL;DR: In uncertainty situations where knowledge is described by a Dempster-Shafer belief function (which is more general than a probability measure), von Neumann-Morgenstern linear utility theory applies and leads to a generalized expected utility representation of preference as discussed by the authors.

TL;DR: Over a period of 4 years, 15 cases of benign positional vertigo (BPV) probably caused by deposition of otoliths in the horizontal semicircular canal are observed.

TL;DR: In this article, the authors describe the convex hull of the incidence vectors of stable matchings and propose a linear program to solve the optimal stable marriage problem as a linear programming problem.

TL;DR: This paper deals with the problem of minimizing the length of a flow shop schedule when lot streaming is invoked, and shows when it is sufficient in the one-job model to use the same sublot sizes for all machines.

TL;DR: In this article, the Lin-Kernighan heuristic consistently produces near-optimal sequences of X-ray diffraction measurements on a four-circle diffractometer.

TL;DR: Techniques for discrete event simulation optimization are classified into four groups: path search methods, patternSearch methods, random methods, and integral methods which are described and a survey of recent literature is presented.

TL;DR: A stochastic model is developed and the optimal value for the individual module failure rate is derived, under the assumptions that a certain cost function is minimized and that the entire system is guaranteed to have an overall failure rate of a prescribed level.

TL;DR: An on-line algorithm is given that uses at most 3.25 times the optimal number of bins for packing rectangles into bins which are unit squares and a result is proved for the case when the items to be packed are squares.

TL;DR: In this paper, the authors give a simple constructive proof of Fulkerson's characterization using a minimum spanning tree algorithm and identify all inequalities that are facets of a spanning tree of a graph.

TL;DR: In this paper, the core of the cooperative cost allocation game (N; c) defined by the cost function c(S), S @? N was shown to be nonempty even if G is series parallel by presenting the unique minimal counter example for such graphs.

TL;DR: A singler server queue serving two classes of customers according to a preemptive resume head of the line priority discipline is considered, under the assumption of a bulk arrival Poisson arrival process, exponential service times, general repair times and exponential interfailure time.

TL;DR: This work superimposes the reliability feature comprising the machine failure process and the ensuing repair actions into production-inventory models, and derives an explicit closed form solution for the steady-state distribution of the inventory level to compute system performance indices of interest related to service level to customers and machine utilization.

TL;DR: In this article, an O(n) time algorithm for the projection of a vector on the simplex of R^n was presented and a linear-time median-finding algorithm was used to determine the median of the components of the vector.

TL;DR: A new decomposition method for large linear programming problems of angular structure that combines the ideas of augmented Lagrangians, simplicial decomposition, column generation and dual ascent is proposed.

TL;DR: The algorithm uses an assignment problem based lower bounding technique, subtour elimination branching rules, and a subtour patching algorithm as an upper bounding procedure to optimally solve the asymmetric traveling salesman problem.

TL;DR: Bartholdi and Platzman as discussed by the authors showed that the worst-case ratio is in fact O(1) and showed that O(lg n) upper bound is tight.

TL;DR: Computer results on different types of problem graphs show that respectable reduction is attained by the Least Cost test, which is considerably improved by replacing shortest path length with 'special distance', a notion based on a min-max measure.

TL;DR: Auditory brainstem response (ABR) thresholds remained unchanged for 2 months, indicating irreversible electrophysiological changes in the inner ear, and hydrocortisone delayed the healing of the perforated tympanic membrane.

TL;DR: An exhaustive search algorithm is presented for the assignment of tasks to processors in a distributed processing system so that the sum of execution and communication costs is minimized.

TL;DR: Using a submodular inequality, and the observation that flow values in capacitated fixed charge networks are often sub-modular, a family of valid inequalities is derived for such networks that includes many of the inequalities derived recently as mentioned in this paper.

TL;DR: A worst-case analysis of an algorithm proposed by Campbell et al. for the m-machine permutation flow-shop problem is presented and the tight best-case performance ratio [m/2] is found.

TL;DR: It is concluded that cholesteatoma surgery should be individualized and that both the canal wall up and canal wall down methods have their place in cholesteletoma surgery.

TL;DR: An efficient algorithm is proposed for the additive and multiplicative models in data envelopment analysis (DEA) that executed in less than 60% of the cpu time required by the revised simplex method.

TL;DR: According to the present study healthy adults do not carry group-A hemolytic streptococci in the nose and seldom if ever in the pharynx, and therefore, isolation of S. pyogenes by bacterial culture is suggestive of a bacterial infection by this agent at these sites.

TL;DR: A simple algorithm is presented for obtaining complete queue lenght distributions using relatively few DFT coefficients for inversion of probability generating functions via discrete Fourier transforms.

TL;DR: Clinical study was necessary for the team to finally confirm the clinical usefulness of this device and focus mostly on the problem of indication for the application of PMEI.

TL;DR: It was concluded from present results that the SP/AP ratio can be a useful indicator to detect -SP dominance, while the SP amplitude can be an indicators to detect cell damage in inner ear diseases.