Cutting Stock Problems
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. COMPARISON OF MIP MODELS FOR THE INTEGRATED LOT-SIZING AND ONE-DIMENSIONAL CUTTING STOCK PROBLEM
ABSTRACT Production processes comprising both the lot-sizing problem and the cutting stock problem are frequent in various industrial sectors. However these problems are usually treated separately, which can generates suboptimal overall solution and consequently causes production losses. In this paper, we propose different mathematical models for the integra
Pesqui. Oper.. Publicado em: 2016-04
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2. Problemas de corte com sobras aproveitáveis e eliminação de simetrias / Cutting stock problems with usable leftover and symmetry breaking
In this work we study two variations of the packing problem where identical rectangular items must be packed into a polyhedron. One of the variations consists in finding the largest amount of rectangular items that can fit in a polyhedron. The other one consists in finding a minimal area polyhedron of a certain type that packs a set of rectangular identical
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/09/2012
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3. Geração de colunas para problemas de corte em duas fases / Column generation for two starge cutting stock problems
The Compartmentalized Knapsack Problem is an extension of the classical Knapsack Problem, where the ordered items are partitioned into classes, in such way that the knapsack must be divided into compartments, each one having limited capacity. In addition, the building of a compartment has a fixed cost and involves a loss of the overall capacity. The objectiv
Publicado em: 2009
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4. Contribution of the LU factorization update in the Simplex method / Contribuição da atualização da decomposição LU no metodo Simplex
Finding efficient solution of linear systems is fundamental in the linear programming problems and the first method to obtain success for this class of problems was the Simplex method. With the objective to develop efficient alternatives to its implementation, techniques of the simplex basis LU factorization update are developed in this thesis to improve the
Publicado em: 2009
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5. Algumas extensões do problema de corte de estoque com sobras de material aproveitáveis / Some extensions of the cutting stock problem with usable leftovers
Os problemas de corte de estoque consistem em cortar um conjunto de objetos dispon´veis em estoque para produzir um conjunto de itens em quantidades e tamanhos especificados, de modo a otimizar uma fun¸cao objetivo. Tais problemas tem in´umeras aplica¸coes industriais e tem sido bastante estudados na literatura. Tipicamente, problemas de corte tem como p
Publicado em: 2009
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6. Uma proposta para resolver o problema de corte de estoque unidimensional com reaproveitamento de sobras por meio de dois objetivos
Problemas de corte de estoque unidimensional consistem em cortar um conjunto de peças disponíveis em estoque para produzir um conjunto de itens em quantidades pré-determinadas, onde apenas o comprimento das peças é relevante. Neste trabalho apresentamos uma definição para o problema de corte de estoque unidimensional em que as perdas geradas pelo proc
Publicado em: 2008
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7. A nonlinear formulation for the unidimensional cutting-stock problem / Uma formulação não-linear para o problema de corte unidimensional
Neste trabalho resolvemos um problema de corte unidimensional não-linear para minimizar o número de objetos processados, setup e desperdício. O termo não-linear representa o setup da máquina de corte. Resolvemos o problema utilizando o pacote MINOS e obtemos a solução inteira através de um procedimento heurístico. Como o número de padrões de corte
Publicado em: 2008
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8. Otimização do processo de corte integrado à produção de bobinas - modelos e métodos de solução / Coupling cutting stock and lot sizing problems in the paper industry: mathematical model and solution methods
An important production programming problem arises in paper industries coupling mul- tiple machine scheduling with cutting stock. From machine scheduling the problem of determining the quantity of jumbos (large rolls of paper) of different types of paper to be produced in each machine arises. These jumbos are then cut to meet the demand for items (smaller ro
Publicado em: 2006
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9. Modelo não-linear para minimizar o numero de objetos processados e o setup num problema de corte unidimensional / Nonlinear model to minimize both the number of processed objets and the number of setups in an cutting stock problem
In this work we introduce a new method to minimize both the number of processed objects and the number of nonzeros cutting patterns (Le., setup) in an one-dimensional cutting stock problem. To do so, we smooth the discontinuous nonlinear function used in Haessler(1975) to represent both objectives: the number of objects and setup number. To generate the cutt
Publicado em: 2005
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10. Toroidal milling of hardened SAE H13 steel
It is estimated that around 65% of the cost of a die or mould is related to the machining processes. Moreover, the literature says that 70% of the time spent in the machining processes of this kind of parts is used in finishing and semi-finishing operations. The high complexity of the machined surfaces makes mandatory the use of ball nose tools, with large o
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2004-03
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11. Redução do número de padrões em problemas de corte de estoque / Pattern reduction in cutting stock problem
In this thesis we focus on the problem of reducing the number of patterns in cutting stock problems. A review of the literature found on this subject is made and new heuristics for this problem are proposed. The first heuristic proposed is composed of three phases. In the first phase, patterns are generated and chosen if they satisfy some pre-established asp
Publicado em: 2003