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A two-stage stochastic optimization model for a gas sale retailer

F. Maggioni, Maria Teresa Vespucci, E. Allevi, Marida Bertocchi, M. Innorta (2008)

Kybernetika

The paper deals with a new stochastic optimization model, named OMoGaS–SV (Optimization Modelling for Gas Seller–Stochastic Version), to assist companies dealing with gas retail commercialization. Stochasticity is due to the dependence of consumptions on temperature uncertainty. Due to nonlinearities present in the objective function, the model can be classified as an NLP mixed integer model, with the profit function depending on the number of contracts with the final consumers, the typology of...

A unified cost function for M/G/1 queueing systems with removable server.

Jesús R. Artalejo (1992)

Trabajos de Investigación Operativa

This article deals with the three classic policies for an M/G/1 queueing system (N, T, and D-policy). The optimum policies were compared in several precedent studies, but the comparison was performed employing different cost functions, so that the D-policy is superior to the N-policy when the cost function is based on the mean work-load, whilst the average queue length is used to show the superiority of the N-policy over the T-policy. In order to achieve a comparison of the three policies under...

A variational model for equilibrium problems in a traffic network

Giandomenico Mastroeni, Massimo Pappalardo (2004)

RAIRO - Operations Research - Recherche Opérationnelle

We propose a variational model for one of the most important problems in traffic networks, namely, the network equilibrium flow that is, traditionally in the context of operations research, characterized by minimum cost flow. This model has the peculiarity of being formulated by means of a suitable variational inequality (VI) and its solution is called “equilibrium”. This model becomes a minimum cost model when the cost function is separable or, more general, when the jacobian of the cost operator...

A variational model for equilibrium problems in a traffic network

Giandomenico Mastroeni, Massimo Pappalardo (2010)

RAIRO - Operations Research

We propose a variational model for one of the most important problems in traffic networks, namely, the network equilibrium flow that is, traditionally in the context of operations research, characterized by minimum cost flow. This model has the peculiarity of being formulated by means of a suitable variational inequality (VI) and its solution is called “equilibrium”. This model becomes a minimum cost model when the cost function is separable or, more general, when the Jacobian of the cost operator...

A variational model for urban planning with traffic congestion

Guillaume Carlier, Filippo Santambrogio (2005)

ESAIM: Control, Optimisation and Calculus of Variations

We propose a variational model to describe the optimal distributions of residents and services in an urban area. The functional to be minimized involves an overall transportation cost taking into account congestion effects and two aditional terms which penalize concentration of residents and dispersion of services. We study regularity properties of the minimizers and treat in details some examples.

A variational model for urban planning with traffic congestion

Guillaume Carlier, Filippo Santambrogio (2010)

ESAIM: Control, Optimisation and Calculus of Variations

We propose a variational model to describe the optimal distributions of residents and services in an urban area. The functional to be minimized involves an overall transportation cost taking into account congestion effects and two aditional terms which penalize concentration of residents and dispersion of services. We study regularity properties of the minimizers and treat in details some examples.

About a special class of nonconvex optimization problems

Libuše Grygarová (1990)

Aplikace matematiky

The article deals with certain nonconvex optimization problem which have features analogous to those of the linear optimization problems. We can find their absolute extrema and the set all optimal points of such nonconvex optimization problem represents the closure of a face of a spherical polyhedron which is its feasible set.

Currently displaying 501 – 520 of 891