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作者：HOOKER, JN
摘要：Deductive algorithmic science has reached a high level of sophistication, but its worst-case and average-case results seldom tell us how well an algorithm is actually going to work in practice. I argue that an empirical science of algorithms is a viable alternative. I respond to misgivings about an empirical approach, including the prevalent notion that only a deductive treatment can be ''theoretical'' or sophisticated. NP-completeness theory, for instance, is interesting partly because it has...
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作者：WILLEMAIN, TR
摘要：Twelve selected expert modelers described themselves as modelers, the models they make, the problems they model, and the way they model. They also expressed opinions about the qualities of effective models, modelers, modeling processes, and desirable modeling clients. Finally, they provided stories about their modeling experiences. Their responses provide benchmarks for developing a modeling science and validate the importance of the craft aspects of OR/MS practice. The paper suggests changes ...
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作者：WORZEL, KJ; VASSIADOUZENIOU, C; ZENIOS, SA
摘要：Increasing performance pressures on fixed-income managers have led to a search for new and creative ways to add to portfolio returns. The largest pension plan sponsors, insurance companies, foundations, and money management firms are using indexed portfolios as their fixed-income assets management strategies since the late 1970s. Tracking a fixed-income index is a difficult task due to transaction costs, portfolio size and diversification restrictions, liquidity requirements, bid/ask spreads, ...
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作者：TRICK, MA
摘要：We examine scheduling problems where we control not only the assignment of jobs to machines, but also the time used by the job on the machine. For instance, many tooling machines allow control of the speed at which a job is run. Increasing the speed incurs costs due to machine wear, but also increases throughput. We discuss some fundamental scheduling problems in this environment and give algorithms for some interesting cases. Some cases are inherently difficult so for these we give heuristics...
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作者：VRANAS, PB; BERTSIMAS, DJ; ODONI, AR
摘要：Motivated by the important problem of congestion costs (they were estimated to be $ 2 billion in 199 1) in air transportation and observing that ground delays are more preferable than airborne delays, we have formulated and studied several integer programming models to assign ground-holding delays optimally in a general network of airports, so that the total (ground plus airborne) delay cost of all flights is minimized. All previous research on this problem has been restricted to the single-ai...
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作者：RINGEL, EI; MODE, CJ
作者单位：Drexel University
摘要：This paper explores the application of stochastic process ideas to answer some fundamental questions about a state system which arises in the Mode Select Beacon System (Mode-S), an air-space management system. A Series of models is developed, based on semi-Markov processes, population models, and Monte Carlo simulation. Computer programs in the APL programming language to implement the models and to process the resulting data are developed. The output of the models illuminate the behavior of t...
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作者：POPKEN, DA
摘要：To remain competitive, manufacturers must seek transportation strategies that both reduce costs and maintain high levels of service. One approach is to consolidate inbound freight at transshipment points. This provides economies of scale and promotes capacity efficient mixes of high and low density items. When service level considerations are included via inventory holding costs, the approach yields a nonlinear network model with multiattribute multicommodity flows. The model is difficult to s...
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作者：ANILY, S; BRAMEL, J; SIMCHILEVI, D
作者单位：Columbia University
摘要：We consider the famous bin packing problem where a set of items must be stored in bins of equal capacity. In the classical version, the objective is to minimize the number of bins used. Motivated by several optimization problems that occur in the context of the storage of items, we study a more general cost structure where the cost of a bin is a concave function of the number of items in the bin. The objective is to store the items in such a way that total cost is minimized. Such cost function...
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作者：RAVI, SS; ROSENKRANTZ, DJ; TAYI, GK
摘要：The dispersion problem arises in selecting facilities to maximize som, function of the distances between the facilities. The problem also arises in selecting nondominated solutions for multiobjective decision making. It is known to be NP-hard under two objectives: maximizing the minimum distance (MAX-MIN) between any pair of facilities and maximizing the average distance (MAX-AVG). We consider the question of obtaining near-optimal solutions. For MAX-MIN, we show that if the distances do not s...
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作者：HIGLE, JL; LOWE, WW; ODIO, R
摘要：Simulation and optimization are among the most commonly used elements in the OR toolkit. Often times, some of the data elements used to define an optimization problem are best described by random variables, yielding a stochastic program. If the distributions of the random variables cannot be specified precisely, one may have to resort to simulation to obtain observations of these random variables. In this paper, we present conditional stochastic decomposition (CSD), a method that may be constr...
