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Consistency checking within local search applied to the frequency assignment with polarization problem

Michel Vasquez, Audrey Dupont, Djamal Habet (2010)

RAIRO - Operations Research

We present a hybrid approach for the Frequency Assignment Problem with Polarization. This problem, viewed as Max-CSP, is treated as a sequence of decision problems, CSP like. The proposed approach combines the Arc-Consistency techniques with a performed Tabu Search heuristic. The resulting algorithm gives some high quality solutions and has proved its robustness on instances with approximately a thousand variables and nearly ten thousand constraints.

Consistency-driven approximation of a pairwise comparison matrix

Esther Dopazo, Jacinto González-Pachón (2003)

Kybernetika

The pairwise comparison method is an interesting technique for building a global ranking from binary comparisons. In fact, some web search engines use this method to quantify the importance of a set of web sites. The purpose of this paper is to search a set of priority weights from the preference information contained in a general pairwise comparison matrix; i.e., a matrix without consistency and reciprocity properties. For this purpose, we consider an approximation methodology within a distance-based...

Constrained 𝐤 -means algorithm for resource allocation in mobile cloudlets

Rasim M. Alguliyev, Ramiz M. Aliguliyev, Rashid G. Alakbarov (2023)

Kybernetika

With the rapid increase in the number of mobile devices connected to the Internet in recent years, the network load is increasing. As a result, there are significant delays in the delivery of cloud resources to mobile users. Edge computing technologies (edge, cloudlet, fog computing, etc.) have been widely used in recent years to eliminate network delays. This problem can be solved by allocating cloud resources to the cloudlets that are close to users. The article proposes a clustering-based model...

Constrained optimality problem of Markov decision processes with Borel spaces and varying discount factors

Xiao Wu, Yanqiu Tang (2021)

Kybernetika

This paper focuses on the constrained optimality of discrete-time Markov decision processes (DTMDPs) with state-dependent discount factors, Borel state and compact Borel action spaces, and possibly unbounded costs. By means of the properties of so-called occupation measures of policies and the technique of transforming the original constrained optimality problem of DTMDPs into a convex program one, we prove the existence of an optimal randomized stationary policies under reasonable conditions.

Constrained optimization: A general tolerance approach

Tomáš Roubíček (1990)

Aplikace matematiky

To overcome the somewhat artificial difficulties in classical optimization theory concerning the existence and stability of minimizers, a new setting of constrained optimization problems (called problems with tolerance) is proposed using given proximity structures to define the neighbourhoods of sets. The infimum and the so-called minimizing filter are then defined by means of level sets created by these neighbourhoods, which also reflects the engineering approach to constrained optimization problems....

Constrained stabilization of a dynamic systems: a case study

Franco Blanchini, S. Cotterli, G. Koruza, S. Miani, R. Siagri, Luciano Tubaro (1999)

Kybernetika

In this work we consider the problem of determining and implementing a state feedback stabilizing control law for a laboratory two-tank dynamic system in the presence of state and control constraints. We do this by exploiting the properties of the polyhedral Lyapunov functions, i. e. Lyapunov functions whose level surfaces are polyhedra, in view of their capability of providing an arbitrarily good approximation of the maximal set of attraction, which is the largest set of initial states which can...

Constrained Steiner trees in Halin graphs

Guangting Chen, Rainer E. Burkard (2003)

RAIRO - Operations Research - Recherche Opérationnelle

In this paper, we study the problem of computing a minimum cost Steiner tree subject to a weight constraint in a Halin graph where each edge has a nonnegative integer cost and a nonnegative integer weight. We prove the NP-hardness of this problem and present a fully polynomial time approximation scheme for this NP-hard problem.

Constrained Steiner trees in Halin graphs

Guangting Chen, Rainer E. Burkard (2010)

RAIRO - Operations Research

In this paper, we study the problem of computing a minimum cost Steiner tree subject to a weight constraint in a Halin graph where each edge has a nonnegative integer cost and a nonnegative integer weight. We prove the NP-hardness of this problem and present a fully polynomial time approximation scheme for this NP-hard problem.

Construction de facettes pour le polytope du sac-à-dos quadratique en 0-1

Alain Faye, Olivier Boyer (2010)

RAIRO - Operations Research

Nous construisons des familles de facettes du polytope du sac-à-dos quadratique en 0-1 selon les deux approches suivantes. Le Boolean quadric polytope (introduit dans le cas sans contraintes par Padberg [12]) contenant le polytope du sac-à-dos quadratique, une première approche consiste à se demander sous quelles conditions une facette du premier est aussi une facette du second et quand ces conditions ne sont pas remplies quels liftings permettent d'en faire une facette. Des réponses à ces questions...

Construction of a Φ-function for two convex polytopes

Y. Stoyan, J. Terno, M. Gil, T. Romanova, G. Scheithauer (2002)

Applicationes Mathematicae

The analytical description of Φ-functions for two convex polytopes is investigated. These Φ-functions can be used for mathematical modelling of packing problems in the three-dimensional space. Only translations of the polytopes are considered. The approach consists of two stages. First the 0-level surface of a Φ-function is constructed, and secondly, the surface is extended to get the Φ-function. The method for constructing the 0-level surface is described in detail.

Construction of fluxes at junctions for the numerical solution of traffic flow models on networks

Vacek, Lukáš, Kučera, Václav (2021)

Programs and Algorithms of Numerical Mathematics

We deal with the simulation of traffic flow on networks. On individual roads we use standard macroscopic traffic models. The discontinuous Galerkin method in space and explicit Euler method in time is used for the numerical solution. We apply limiters to keep the density in an admissible interval as well as prevent spurious oscillations in the numerical solution. To solve traffic networks, we construct suitable numerical fluxes at junctions. Numerical experiments are presented.

Continuous reformulations and heuristics for the euclidean travelling salesperson problem

Tuomo Valkonen, Tommi Kärkkäinen (2009)

ESAIM: Control, Optimisation and Calculus of Variations

We consider continuous reformulations of the euclidean travelling salesperson problem (TSP), based on certain clustering problem formulations. These reformulations allow us to apply a generalisation with perturbations of the Weiszfeld algorithm in an attempt to find local approximate solutions to the euclidean TSP.

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