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Acidentes na Criança: «Mea Culpae»! Experiência dum Hospital Distrital
F., Carvalho; J. M., Gonçalves OliveiraOs acidentes constituem a primeira causa de morte na idade pediátrica e são a causa mais importante de ida ao serviço de urgência.Os autores propuseram-se determinar o volume de acidentes que recorriam ao Hospital Distrital de Vila Nova de Famalicão e identificar os agentes causais e associados na origem dos traumatismos. Foram inquiridas 586 crianças através de um questionário efectuado ao seu acompanhante. Ut...
Discrete lot sizing and scheduling on parallel machines: description of a colum...
Duarte, António J.S.T.; Carvalho, J.M.V. Valério deIn this work, we study the discrete lot sizing and scheduling problem (DSLP) in identical parallel resources with (sequence-independent) setup costs and inventory holding costs. We propose a Dantzig-Wolfe decomposition of a known formulation and describe a branch-and-price and column generation procedure to solve the problem to optimality. Preliminary results show that the lower bounds provided by the reformula...
Discrete lot sizing and scheduling on parallel machines: description of a colum...
Duarte, António J.S.T.; Carvalho, J.M. Valério deIn this work, we study the discrete lot sizing and scheduling problem (DSLP) in identical parallel resources with (sequence-independent) setup costs and inventory holding costs. We propose a Dantzig- Wolfe decomposition of a known formulation and describe a branch-and-price and column generation procedure to solve the problem to optimality. Preliminary results show that the lower bounds provided by the reformul...
Exact and heuristic approaches for lot splitting and scheduling on identical pa...
Pimentel, Carina; Alvelos, Filipe Pereira e; Duarte, António Jorge da Silva Trindade; Carvalho, J. M. Valério deIn this paper, we address a lot splitting and scheduling problem existent in a textile factory. The factory we study produces a set of products that are made of, or assembled from, a list of components. During production, each component can be split into one or several lots of different sizes and each lot will be produced independently on one of a group of identical parallel machines. We formulate the problem i...
Heuristic approaches for a practical lot splitting and scheduling problem
Pimentel, Carina; Alvelos, Filipe; Carvalho, J.M. Valério; Duarte, António J.S.T.In this talk we present some heuristic approaches for a real world lot splitting and scheduling problem of a Textile factory. The problem consists of finding a weekly production plan for the knitting section of the company, establishing the quantities to produce of each component (organized in one or several lots), and where and when (starting/completion times) to produce them. Two important objectives to achie...
Parallel machine scheduling using free software: an application
Duarte, António J.S.T.; Carvalho, J.M. ValérioWe will show how to implement large scale optimization by only using freely available software tools. We solve exactly a parallel machine scheduling problem with identical parallel machines and malleable tasks, subject to arbitrary release dates and due dates. The objective is to minimize a function of late work and setup costs. We use the COIN-OR BCP framework to implement column generation to solve a model th...
Heuristic approaches for lot splitting and scheduling in identical parallel mac...
Pimentel, Carina; Alvelos, Filipe; Carvalho, J.M. Valério; Duarte, António J.S.T.In this paper we address a practical lot splitting and scheduling problem of a textile company that produces fine knitted garments. The problem consists of finding a weekly production plan for the knitting section, in which the garment components are produced in a set of parallel machines. We solve the problem in two steps using heuristic approaches. In the first step one of two heuristics (a network flow heuri...
Solving a multiprocessor problem by column generation and branch-and-price
Duarte, António J.S.T.; Carvalho, J.M. ValérioThis work presents an algorithm for solving exactly a scheduling problem with identical parallel machines and malleable tasks, subject to arbitrary release dates and due dates. The objective is to minimize a function of late work and setup costs. A task is malleable if we can freely change the set of machines assigned to its processing over the time horizon. We present an integer programming model, a Dantzig-Wo...
A fast heuristic for a lot splitting and scheduling problem of a textile industry
Pimentel, Carina; Alvelos, Filipe; Carvalho, J.M. Valério; Duarte, António J.S.T.In this paper we address a lot splitting and scheduling problem of a Textile factory that produces garment pieces. Each garment piece is made of a set of components that are produced on the knitting section of the company. The problem consists of finding a weekly production plan for the knitting section, establishing the quantities to produce of each component (organized in one or several lots), and where and w...
Perda e conservação dos recursos genéticos vegetais.
CARVALHO, J. M. F. C.; SILVA, M. M. de A.; MEDEIROS, M. J. L. e2009
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