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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

ProgramaÃÃo linear inteira aplicada no planejamento da alocaÃÃo de vagÃes de carga / Integer linear programming applyed for railroad freight wagons allocation planning

Marcello Calado Vieira de Melo 09 October 2008 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Universidade Federal do Cearà / O atendimento da demanda de transporte de carga està relacionado ao processo de alocaÃÃo do vagÃo, que por sua vez, està associado à maneira pela qual a decisÃo à tomada. A distribuiÃÃo dos vagÃes aos terminais de carregamento depende do planejamento e da movimentaÃÃo dos vagÃes vazios, sendo a viagem deste, a parcela de maior impacto financeiro sobre o sistema ferroviÃrio. Desta forma, um mecanismo eficiente de distribuiÃÃo de vagÃo à vital para as estradas de ferro, pois proporciona importantes ganhos operacionais e de custos. Assim, o propÃsito deste trabalho à analisar o problema relacionado à distribuiÃÃo dos vagÃes de carga e desenvolver modelos em ProgramaÃÃo Linear Inteira, que ofereÃam ao analista a oportunidade de conhecer em detalhes, (em um nÃvel tÃtico e operacional), as dificuldades enfrentadas pela ferrovia, bem como avaliar a proposiÃÃo de metas dos tempos de retenÃÃo em pÃtios, tempos de deslocamento, nÃmero de vagÃes retidos para manutenÃÃo, necessidade do aumento da frota e, atà mesmo, a rentabilidade das demandas ou a viabilidade de execuÃÃo do programa de transporte diante das premissas operacionais em vigor / Load transportation attendance for demand is related to the process of wagon allocation that in its turn, is associated with the way by which the decision is taken. The distribution of the wagons to the shipment terminals depends on the planning and movement of the empty wagons, being the trip of the empty wagon the parcel with bigger financial impact on the railroad system. In such a way, an efficient mechanism for wagon distribution is vital for the railroads, therefore providing important operational gains and cost savings. Thus, the purpose of this study is to analyze the problem related to the distribution of freight wagons and develop models in integer linear programming that will offer the analyst the opportunity to know in detail (in a tactical and operational level) the difficulties faced by the railroad, and to evaluate the setting of goals for retention times in rail yards, transit time, number of cars retained for maintenance, need to increase the fleet and even the profitability of the request or the feasibility for the implementation of the transport towards the operational assumptions in place

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