156,428 research outputs found

    Models and Solution Techniques for Frequency Assignment Problems.

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    Wireless communication is used in many different situations such as mobile telephony, radio and TV broadcasting, satellite communication, and military operations. In each of these situations a frequency assignment problem arises with application specific characteristics. Researchers have developed different modelling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion. This survey gives an overview of the models and methods that the literature provides on the topic. We present a broad description of the practical settings in which frequency assignment is applied. We also present a classification of the different models and formulations described in the literature, such that the common features of the models are emphasized. The solution methods are divided in two parts. Optimization and lower bounding techniques on the one hand, and heuristic search techniques on the other hand. The literature is classified according to the used methods. Again, we emphasize the common features, used in the different papers. The quality of the solution methods is compared, whenever possible, on publicly available benchmark instances.operations research and management science;

    Models and Solution Techniques for Frequency Assignment Problems

    Get PDF
    Wireless communication is used in many different situations such as mobile telephony, radio and TV broadcasting, satellite communication, and military operations. In each of these situations a frequency assignment problem arises with application specific characteristics. Researchers have developed different modeling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion. This survey gives an overview of the models and methods that the literature provides on the topic. We present a broad description of the practical settings in which frequency assignment is applied. We also present a classification of the different models and formulations described in the literature, such that the common features of the models are emphasized. The solution methods are divided in two parts. Optimization and lower bounding techniques on the one hand, and heuristic search techniques on the other hand. The literature is classified according to the used methods. Again, we emphasize the common features, used in the different papers. The quality of the solution methods is compared, whenever possible, on publicly available benchmark instances

    Models and Solution Techniques for Frequency Assignment Problems

    Get PDF
    Wireless communication is used in many different situations such as mobile telephony, radio and TV broadcasting, satellite communication, and military operations. In each of these situations a frequency assignment problem arises with application specific characteristics. Researchers have developed different modeling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion. This survey gives an overview of the models and methods that the literature provides on the topic. We present a broad description of the practical settings in which frequency assignment is applied. We also present a classification of the different models and formulations described in the literature, such that the common features of the models are emphasized. The solution methods are divided in two parts. Optimization and lower bounding techniques on the one hand, and heuristic search techniques on the other hand. The literature is classified according to the used methods. Again, we emphasize the common features, used in the different papers. The quality of the solution methods is compared, whenever possible, on publicly available benchmark instances

    Interactive airline fleet assignment model

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    Cover titleSeries statement hand-written on coverMay 1981Includes bibliographical references (p. 105-108)This thesis investigates the Airline Fleet Assignment models which have been designed during the past 10 years within MIT's Flight Transportation Laboratory. Emphasis is placed on developing an interactive computer system, called IFA/1, which simplifies the use of fleet assignment models and improves the insertion or modification of necessary data. The first section gives a general review of the mathematical models used for vehicle planning in air transportation, with special attention given to the Airline Fleet Assignment and Fleet Planning problem. The techniques used to solve these problems are discussed, and one model of particular interest, the FA4 model, is introduced. The second part describes how FA4 is used in practice and points out some of its major deficiencies. An improvement is proposed through the means of an interactive computer package available at the Flight Transportation Laboratory. Future modifications to this interactive system are also discussed. Finally, an alternative solution is suggested to one of the theoretical problems which underlies the Fleet Assignment model: the "phantom frequency problem". This issue is discussed and a new set of equations is proposed which improves the efficiency of the model

    Referee assignment in the Chilean football league using integer programming and patterns

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    This article uses integer linear programming to address the referee assignment problem in the First Division of the Chilean professional football league. The proposed approach considers balance in the number of matches each referee must officiate, the frequency of each referee being assigned to a given team, the distance each referee must travel over the course of a season, and the appropriate pairings of referee experience or skill category with the importance of the matches. Two methodologies are studied, one traditional and the other a pattern-based formulation inspired by the home-away patterns for scheduling season match calendars. Both methodologies are tested in real-world and experimental instances, reporting results that improve significantly on the manual assignments. The pattern-based formulation attains major reductions in execution times, solving real instances to optimality in just a few seconds, while the traditional one takes anywhere from several minutes to more than an hour.Fil: AlarcĂłn, Fernando. Universidad de Chile; ChileFil: Duran, Guillermo Alfredo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de CĂĄlculo; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Guajardo, Mario. Norwegian School of Economics; Norueg
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