-
作者：Atamtürk, A; Johnson, EL; Linderoth, JT; Savelsbergh, MWP
作者单位：University System of Georgia; Georgia Institute of Technology
摘要：We discuss an integer linear programming modeling system based on relational algebra. in this system, all modeling related activities, such as model formulation, model instantiation, and model and instance management, are done using simple operations such as selection, projection, and predicated join.
-
作者：Roemer, TA; Ahmadi, R; Wang, RH
作者单位：University of California System; University of California Los Angeles
摘要：Increasingly shorter product life cycles impel firms to design, develop, and market more products in less time than ever before. Overlapping of design and development stages is commonly regarded as the most promising strategy to reduce product development times. However, overlapping typically requires additional resources and can be costly. Our research addresses the trade-off between product development time and costs and introduces an algorithm to determine an appropriate overlapping strateg...
-
作者：Fortz, B; Labbé, M; Maffioli, F
作者单位：Universite Libre de Bruxelles; Polytechnic University of Milan
摘要：We study the problem of designing at minimum cost a two-connected network such that the shortest cycle to which each edge belongs (a mesh) does not exceed a given length K. This problem arises in the design of fiber-optic-based backbone telecommunication networks. A Branch-and-Cut approach to this problem is presented for which we introduce several families of valid inequalities and discuss the corresponding separation algorithms. Because the size of the problems solvable to optimality by this...
-
作者：Lawson, DG; Porteus, EL
作者单位：Agilent Technologies; University of British Columbia; Stanford University
摘要：After reformulating Clark and Scarfs (1960) classical serial multi-echelon model so that the lead time between adjacent echelons is one week (period), the option to expedite between each resulting echelon is added. Thus, each week requires a decision to be made at each echelon on how many units to expedite in from the next upstream echelon (to be received immediately) and how many to regular order (to be received in one week), with the remainder detained (left as is). The model can be interpre...
-
作者：Hochbaum, DS; Chen, A
作者单位：University of California System; University of California Berkeley; University of California System; University of California Berkeley
摘要：The open-pit mining problem is to determine the contours of a mine. based on economic data and engineering feasibility requirements, to yield maximum possible net income. This practical problem needs to be solved for very large data sets. In practice, moreover, it is necessary to test multiple scenarios, taking into account a variety of realizations of geological predictions and forecasts of ore value. The industry is experiencing computational difficulties in solving the problem. Yet, the pro...
-
作者：Vanderbeck, F
作者单位：Universite de Bordeaux
摘要：The cutting stock problem is that of finding a cutting of stock material to meet demands for small pieces of prescribed dimensions while minimising the amount of waste. Because changing over from one cutting pattern to another involves significant setups, an auxiliary problem is to minimise the number of different patterns that are used. The pattern minimisation problem is significantly more complex, but it is of great practical importance. In this paper, we propose an integer programming form...
-
作者：Gutierrez, G; Paul, A
作者单位：University of Texas System; University of Texas Austin; State University System of Florida; University of Florida
摘要：The problem of designing a contract mechanism to allocate the component subprojects of a large project to a pool of contractors has important implications for project success. Our research analytically addresses issues involved in diversifying risk for the project owner by partitioning the project and assigning the subprojects to multiple contractors whose performance characteristics are imperfectly known. We begin by giving a precise analytical treatment of the effect of activity variance on ...
-
作者：Yakowitz, S; L'Ecuyer, P; Vázquez-Abad, F
作者单位：University of Arizona; Universite de Montreal
摘要：This study concerns a generic model-free stochastic optimization problem requiring the minimization of a risk function defined on a given bounded domain in a Euclidean space. Smoothness assumptions regarding the risk function are hypothesized, and members of the underlying space of probabilities are presumed subject to a large deviation principle; however, the risk function may well be nonconvex and multimodal. A general approach to finding the risk minimizer on the basis of decision/observati...
-
作者：Iravani, SMR; Duenyas, I; Olsen, TL
作者单位：Northwestern University; University of Michigan System; University of Michigan
摘要：We consider a production/inventory system consisting of M machines and K (K less than or equal toM) repair crews in which machines are subject to time-dependent failures. The repair operations an each machine require one repair crew during the whole operation. In this production/inventory system, each machine is assigned to produce a different item according to a make-to-stock routine. Inventories of each item service a Poisson demand process, and the unsatisfied demands are lost. The objectiv...
-
作者：Chao, XL; Scott, C
作者单位：North Carolina State University; University of California System; University of California Irvine
摘要：Given that the total service effort in a multiple-server environment is fixed, it is generally known that the single-server system yields the minimum time a customer spends in the system. However, in many manufacturing as well as service applications the waiting time in the queue is more significant than total time in the system. We consider several such queueing design problems and show that the results for minimizing the waiting time in the queue are markedly different from those for minimiz...
