Operations Research

最新文章

• The probabilistic set-covering problem AI翻译
  作者：Beraldi, P; Ruszczynski, A
  作者单位：University of Calabria; Rutgers University System; Rutgers University New Brunswick
  摘要：In a probabilistic set-covering problem the right-hand side is a random binary vector and the covering constraint has to be satisfied with some prescribed probability. We analyze the structure of the set of probabilistically efficient points of binary random vectors, develop methods for their enumeration, and propose specialized branch-and-bound algorithms for probabilistic set-covering problems.
• Algorithms for radio link frequency assignment: The CALMA project AI翻译
  作者：Aardal, K; Hurkens, C; Lenstra, JK; Tiourine, S
  作者单位：Utrecht University; Eindhoven University of Technology
  摘要：The radio link frequency assignment problem occurs when a network of radio links has to be established. Each link must be assigned an operating frequency from a given domain. The assignment has to satisfy certain restrictions so as to limit the interference between links. The number of frequencies used is to be minimized. Problems of this type were investigated within the CALMA project by a consortium consisting of research groups from Delft, Eindhoven, London, Maastricht, Norwich, and Toulous...
• D-optimal sequential experiments for generating a simulation-based cycle time-throughput curve AI翻译
  作者：Park, S; Fowler, JW; Mackulak, GT; Keats, JB; Carlyle, WM
  作者单位：Arizona State University; Arizona State University-Tempe
  摘要：A cycle time-throughput curve quantifies the relationship of average cycle time to throughput rates in a manufacturing system. Moreover, it indicates the asymptotic capacity of a system. Such a curve is used to characterize system performance over a range of start rates. Simulation is a fundamental method for generating such curves since simulation can handle the complexity of real systems with acceptable precision and accuracy. A simulation-based cycle time-throughput curve requires a large a...
• Managing learning and turnover in employee staffing AI翻译
  作者：Gans, N; Zhou, YP
  作者单位：University of Pennsylvania; University of Washington; University of Washington Seattle
  摘要：We study the employee staffing problem in a service organization that uses employee service capacity to meet random, nonstationary service requirements. The employees experience learning and turnover on the job, and we develop a Markov Decision Process (MDP) model which explicitly represents the stochastic nature of these effects. Theoretical results show that the optimal hiring policy is of a state-dependent hire-up-to type, similar to an inventory order-up-to policy. For two important specia...
• Inventory cost rate functions with nonlinear shortage costs AI翻译
  作者：Rosling, K
  作者单位：Vaxjo University; Linnaeus University
  摘要：This article considers five cost-rate models for inventory control, each summarizing the expected holding and shortage costs per period as a function of the inventory position. All models have linear holding costs and shortage cost coefficients of dimension [$/unit/period], [$/unit], and [$/period]. The latter two coefficients may be the shadow costs of a fill-rate and a ready-rate service constraint, respectively. One of the cost-rate models is a new suggestion, intended to facilitate modelin...
• Finite-size facility placement in the presence of barriers to rectilinear travel AI翻译
  作者：Savas, S; Batta, R; Nagi, R
  作者单位：Koc University; State University of New York (SUNY) System; University at Buffalo, SUNY
  摘要：We consider the placement (location and orientation) of a single finite-size (finite-area, arbitrary shape) facility in the plane under the assumption that all travel occurs according to the rectilinear (or Manhattan) metric in the presence of impenetrable barriers to travel. Facility users are distributed over a finite set of demand points. The facility serves the users via a service point (server) located on the boundary of the facility. We consider an interactive model in the sense that the...
• Brownian approximations of multiclass open-queueing networks AI翻译
  作者：Chen, H; Shen, XY; Yao, DD
  作者单位：University of British Columbia; Columbia University
  摘要：We study a multiclass open-queueing network with a set of single-server stations that operate under a combination of FIFO (first-in-first-out) and priority service disciplines, and are subject to random breakdowns. Assuming that the primitive processes-in particular, external arrivals, service requirements, service capacities (up and down times), and the routing mechanism-follow two-moment approximations (based on functional central limit theorems), we develop a semi-martingale reflected Brown...
• Linear facility location in three dimensions - Models and solution methods AI翻译
  作者：Brimberg, J; Juel, H; Schöbel, A
  作者单位：University of Prince Edward Island; Universite de Montreal; HEC Montreal; Technical University of Denmark; University of Kaiserslautern
  摘要：We consider the problem of locating a line or a line segment in three-dimensional space, such that the sum of distances from the facility represented by the line (segment) to a given set of points is minimized. An example is planning the drilling of a mine shaft, with access to ore deposits through horizontal tunnels connecting the deposits and the shaft. Various models of the problem are developed and analyzed, and efficient solution methods are given.
• On the effectiveness of zero-inventory-ordering policies for the economic lot-sizing model with a class of piecewise linear cost structures AI翻译
  作者：Chan, LMA; Muriel, A; Shen, ZJ; Simchi-Levi, D
  作者单位：University of Toronto; University of Massachusetts System; University of Massachusetts Amherst; State University System of Florida; University of Florida; Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT)
  摘要：We consider an economic lot-sizing problem with a special class of piecewise linear ordering costs, which we refer to as the class of modified all-unit discount cost functions. Such an ordering cost function represents transportation costs charged by many less-than-truckload carriers. We show that even special cases of the lot-sizing problem are NP-hard and therefore analyze the effectiveness of easily implementable policies. In particular, we demonstrate that there exists a zero-inventory-ord...
• When uncertainty is beneficial: Interesting implications for the hydrocarbon discovery process AI翻译
  作者：Gerchak, Y; He, QM; Fuller, JD; Chungcharoen, E
  作者单位：Tel Aviv University; Dalhousie University; University of Waterloo; Thammasat University
  摘要：Consider a basin with remaining undiscovered fields, in which both field sizes and their number are uncertain. Assuming that the probability of finding a field is increasing in its size, we show that the expected size of the first remaining field discovered, which is of particular importance, is increasing in the variability of field sizes, and results from a simulation model of exploration illustrate this trend for the first several fields discovered. We also provide simple bounds on the expe...