Displaying similar documents to “Flow Polyhedra and Resource Constrained Project Scheduling Problems”

Optimization of an SMD placement machine and flows in parametric networks

Katarína Cechlárová, Tamás Fleiner (2011)

Kybernetika

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In the minimization of the number of subtours made by the insertion head of an SMD placement machine a variant of the network flow problem arose. In a network with n vertices and m arcs a set F of arcs (parametrized arcs) is given. The task is to find a flow of a given size such that the maximum of flow values along the arcs from F is minimized. This problem can be solved by a sequence of maximum flow computations in modified networks where the capacities of the parametrized arcs are...

Lagrangean Heuristic for a Multi-Plant Lot-Sizing Problem with Transfer and Storage Capacities

Samuel Deleplanque, Safia Kedad-Sidhoum, Alain Quilliot (2013)

RAIRO - Operations Research - Recherche Opérationnelle

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The paper addresses a multi-item, multi-plant lot-sizing problem with transfer costs and capacity constraints. The problem is reformulated according to a multi-commodity flow formalism, and decomposed, through Lagrangean relaxation, into a master facility location problem and a slave minimal cost multi-commodity flow problem. The decomposition framework gives rise in a natural way to designing a Lagrangean based heuristic. Numerical experiments showing the efficiency of the proposed...

Separable convexification and DCA techniques for capacity and flow assignment problems

P. Mahey, Thai Q. Phong, H. P.L. Luna (2010)

RAIRO - Operations Research

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We study a continuous version of the capacity and flow assignment problem (CFA) where the design cost is combined with an average delay measure to yield a non convex objective function coupled with multicommodity flow constraints. A separable convexification of each arc cost function is proposed to obtain approximate feasible solutions within easily computable gaps from optimality. On the other hand, DC (difference of convex functions) programming can be used to compute accurate upper...

On bounded channel flows of viscoelastic fluids

Marshall J. Leitman, Epifanio G. Virga (1988)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti

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We show that the smooth bounded channel flows of a viscoelastic fluid exhibit the following qualitative feature: Whenever the channel is sufficiently wide, any bounded velocity field satisfying the homogeneous equation of motion is such that if the flow stops at some time, then the flow is never unidirectional throughout the channel. We first demonstrate the qualitative property of the bounded channel flows. Then we show explicitly how a piecewise linear approximation of a relaxation...

A numerical study of non-cavitating and cavitating liquid flow around a hydrofoil

François Beux, Maria-Vittoria Salvetti, Alexey Ignatyev, Ding Li, Charles Merkle, Edoardo Sinibaldi (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

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The results of a workshop concerning the numerical simulation of the liquid flow around a hydrofoil in non-cavitating and cavitating conditions are presented. This workshop was part of the conference “Mathematical and Numerical aspects of Low Mach Number Flows” (2004) and was aimed to investigate the capabilities of different compressible flow solvers for the low Mach number regime and for flows in which incompressible and supersonic regions are simultaneously present. Different physical...