-
作者：Tucciarelli, T; Karatzas, GP; Pinder, GF
作者单位：University of Palermo; University of Vermont
摘要：A new algorithm for the solution of the groundwater quality management problem is presented. The method assumes that most of the computational effort in such problems involves evaluation of the concentrations and their derivatives with respect to the pumping rates at the control points. The methodology proposed herein is a combination of the cutting plane method and the primal method. In this approach each line search moves from a feasible point towards the solution of a subproblem with linear...
-
作者：Savelsbergh, M; Sol, M
作者单位：University System of Georgia; Georgia Institute of Technology
摘要：We present DRIVE (Dynamic Routing of Independent VEhicles), a planning module to be incorporated in a decision support system for the direct transportation at Van Gend and Loos BV. Van Gend and Loos BV is the largest company providing road transportation in the Benelux, with about 1400 vehicles transporting 160,000 packages from thousands of senders to tens of thousands of addressees per day. The heart of DRIVE is a branch-and-price algorithm. Approximation and incomplete optimization techniqu...
-
作者：Saaty, TL; Vargas, LG
作者单位：Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh
摘要：Judgments are needed in medical diagnosis to determine what tests to perform given certain symptoms. For many diseases, what information to gather on symptoms and what combination of symptoms lead to a given disease are not well known. Even when the number of symptoms is small, the required number of experiments to generate adequate statistical data can be unmanageably large. There is need in diagnosis for an integrative model that incorporates both statistical data and expert judgment. When s...
-
作者：Bertsimas, D; Teo, CP
作者单位：Massachusetts Institute of Technology (MIT)
摘要：In recent years approximation algorithms based on primal-dual methods have been successfully applied to a broad class of discrete optimization problems. In this paper, we propose a generic primal-dual framework to design and analyze approximation algorithms for integer programming problems of the covering type that uses valid inequalities in its design. The worst-case bound of the proposed algorithm is related to a fundamental relationship (called strength) between the set of valid inequalitie...
-
作者：Lee, TYS
作者单位：University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital
摘要：The evolution of communication technology and the competitive software design environment dictates that performance characterization involves iterations between real-world design and its representation for modeling purposes. In this paper, models and analytical techniques are developed to evaluate the performance of single-server polling computer and communication systems, e.g., multiplexers or local area networks with a single token passing medium access protocol. We present a novel methodolo...
-
作者：Reiman, MI; Wein, LM
作者单位：Alcatel-Lucent; Lucent Technologies; AT&T; Nokia Corporation; Nokia Bell Labs; Massachusetts Institute of Technology (MIT)
摘要：We analyze two scheduling problems for a queueing system with a single server and two customer classes, Each class has its own renewal arrival process, general service time distribution, and holding cost rate. In the first problem, a setup cost is incurred when the server switches from one class to the other, and the objective is to minimize the long-run expected average cost of holding customers and incurring setups. The setup cost is replaced by a setup time in the second problem, where the ...
-
作者：Chen, PC; Hansen, P; Jaumard, B; Tuy, H
作者单位：Universite de Montreal; Universite de Montreal; HEC Montreal
摘要：D.-c. programming is a recent technique of global optimization that allows the solution of problems whose objective function and constraints can be expressed as differences of convex (i.e., d.-c.) functions. Many such problems arise in continuous location theory. The problem first considered is to locate a known number of source facilities to minimize the sum of weighted Euclidean distances between a user's fixed location and the source facility closest to the location of each user. We also ap...
-
作者：Liu, Z; Righter, R
作者单位：Universite Cote d'Azur; Inria; Santa Clara University
摘要：We consider optimal load balancing in a distributed computing environment consisting of homogeneous unreliable processors. Each processor receives its own sequence of tasks from outside users, some of which can be redirected to the other processors. Processing times are independent and identically distributed with an arbitrary distribution. The arrival sequence of outside tasks to each processor may be arbitrary as long as it is independent of the state of the system. Processors may fail, with...
-
作者：Avramidis, AN; Wilson, JR
作者单位：Cornell University; North Carolina State University
摘要：A simulation-based quantile estimator measures the level of system performance that can be delivered with a prespecified probability. To estimate selected quantiles of the response of a finite-horizon simulation, we develop procedures based on correlation-induction techniques for variance reduction, with emphasis on antithetic variates and Latin hypercube sampling. These procedures achieve improved precision by controlling the simulation's random-number inputs as an integral part of the experi...
-
作者：Chen, FR; Zheng, YS
作者单位：Columbia University; University of Pennsylvania
摘要：We study echelon-stock (R, nQ) policies in a multistage, serial inventory system with compound Poisson demand. We. provide a simple method for determining near-optimal control parameters. This is achieved in two steps. First, we establish lower and upper bounds on the cost function by over- and under-charging a penalty cost to each upstream stage for holding inadequate stock. Second, we minimize the bounds, which are simple, separable functions of the control parameters, to obtain heuristic so...
