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Semi-Definite positive Programming Relaxations for Graph Kn-Coloring in Frequency Assignment

Philippe Meurdesoif, Benoît Rottembourg (2010)

RAIRO - Operations Research

In this paper we will describe a new class of coloring problems, arising from military frequency assignment, where we want to minimize the number of distinct n-uples of colors used to color a given set of n-complete-subgraphs of a graph. We will propose two relaxations based on Semi-Definite Programming models for graph and hypergraph coloring, to approximate those (generally) NP-hard problems, as well as a generalization of the works of Karger et al. for hypergraph coloring, to find good feasible...

Semi-Markov-based approach for the analysis of open tandem networks with blocking and truncation

Walenty Oniszczuk (2009)

International Journal of Applied Mathematics and Computer Science

This paper describes an analytical study of open two-node (tandem) network models with blocking and truncation. The study is based on semi-Markov process theory, and network models assume that multiple servers serve each queue. Tasks arrive at the tandem in a Poisson fashion at the rate λ, and the service times at the first and the second node are nonexponentially distributed with means sA and sB , respectively. Both nodes have buffers with finite capacities. In this type of network, if the second...

Sensitivity examination of the simulation result of discrete event dynamic systems with perturbation analysis.

Tamas Koltai, Juan Carlos Larrañeta, Luis Onieva, Sebastián Lozano (1994)

Qüestiió

Simulation completed with perturbation analysis provides a new approach for the optimal control of queuing network type systems. The objective of this paper is to calculate the sensitivity range of finite zero-order perturbation, that is, to determine the maximum and minimum size of perturbation within which zero-order propagation rules can be applied. By the introduction of the concept of virtual queue and first and second level no-input and full-output matrices, an algorithm is provided which...

Separable convexification and DCA techniques for capacity and flow assignment problems

P. Mahey, Thai Q. Phong, H. P. L. Luna (2001)

RAIRO - Operations Research - Recherche Opérationnelle

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 bounds and...

Separable convexification and DCA techniques for capacity and flow assignment problems

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

RAIRO - Operations Research

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 bounds and...

Service network design in short and local fresh food supply chain

Maxime Ogier, Van-Dat Cung, Julien Boissière (2013)

RAIRO - Operations Research - Recherche Opérationnelle

This paper aims at developing efficient solving methods for an original service network design problem imbued with sustainable issues. Indeed the network has to be designed for short and local supply chain and for fresh food products. The original features of the problem are the seasonality of supply, the limitation of transshipments for a product and no possibility of storage between consecutive periods. Decisions at strategic and tactical level are (1) decisions on a subset of hubs to open among...

Sharp summability for Monge transport density via interpolation

Luigi De Pascale, Aldo Pratelli (2004)

ESAIM: Control, Optimisation and Calculus of Variations

Using some results proved in De Pascale and Pratelli [Calc. Var. Partial Differ. Equ. 14 (2002) 249-274] (and De Pascale et al. [Bull. London Math. Soc. 36 (2004) 383-395]) and a suitable interpolation technique, we show that the transport density relative to an L p source is also an L p function for any 1 ≤ p ≤ + ∞ .

Sharp summability for Monge Transport density via Interpolation

Luigi De Pascale, Aldo Pratelli (2010)

ESAIM: Control, Optimisation and Calculus of Variations

Using some results proved in De Pascale and Pratelli [Calc. Var. Partial Differ. Equ.14 (2002) 249-274] (and De Pascale et al. [Bull. London Math. Soc.36 (2004) 383-395]) and a suitable interpolation technique, we show that the transport density relative to an Lp source is also an Lp function for any 1 ≤ p ≤ + ∞ .

Signpost systems and spanning trees of graphs

Ladislav Nebeský (2006)

Czechoslovak Mathematical Journal

By a ternary system we mean an ordered pair ( W , R ) , where W is a finite nonempty set and R ⊆ W × W × W . By a signpost system we mean a ternary system ( W , R ) satisfying the following conditions for all x , y , z ∈ W : if ( x , y , z ) ∈ R , then ( y , x , x ) ∈ R and ( y , x , z ) ∉ R ; if x ≠ y , then there exists t ∈ W such that ( x , t , y ) ∈ R . In this paper, a signpost system is used as a common description of a connected graph and a spanning tree of the graph. By a ct-pair we mean an ordered pair ( G , T ) , where G is a connected graph and T is a spanning tree of G . If ( G , T ) is a ct-pair, then by the guide to...

Simulated Annealing and Tabu Search for Discrete-Continuous Project Scheduling with Discounted Cash Flows

Grzegorz Waligóra (2014)

RAIRO - Operations Research - Recherche Opérationnelle

Discrete-continuous project scheduling problems with positive discounted cash flows and the maximization of the NPV are considered. We deal with a class of these problems with an arbitrary number of discrete resources and one continuous, renewable resource. Activities are nonpreemptable, and the processing rate of an activity is a continuous, increasing function of the amount of the continuous resource allotted to the activity at a time. Three common payment models – Lump Sum Payment, Payments at...

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