Articles de revista
http://hdl.handle.net/2117/3430
20190717T16:32:34Z

An axiomatization for two power indices for (3,2)simple games
http://hdl.handle.net/2117/133317
An axiomatization for two power indices for (3,2)simple games
Benardi, Giulia; Freixas Bosch, Josep
The aim of this work is to give a characterization of the Shapley–Shubik and the Banzhaf power indices for (3,2)simple games. We generalize to the set of (3,2)simple games the classical axioms for power indices on simple games: transfer, anonymity, null player property and efficiency. However, these four axioms are not enough to uniquely characterize the Shapley–Shubik index for (3,2)simple games. Thus, we introduce a new axiom to prove the uniqueness of the extension of the Shapley–Shubik power index in this context. Moreover, we provide an analogous characterization for the Banzhaf index for (3,2)simple games, generalizing the four axioms for simple games and adding another property.
Electronic version of an article published as International Game Theory Review, Vol. 21, Issue 1, 1940001, 2019, p. 124. DOI: 10.1142/S0219198919400012] © World Scientific Publishing Company https://wwwworldscientificcom.recursos.biblioteca.upc.edu/doi/abs/10.1142/S0219198919400012
20190522T08:45:25Z
Benardi, Giulia
Freixas Bosch, Josep
The aim of this work is to give a characterization of the Shapley–Shubik and the Banzhaf power indices for (3,2)simple games. We generalize to the set of (3,2)simple games the classical axioms for power indices on simple games: transfer, anonymity, null player property and efficiency. However, these four axioms are not enough to uniquely characterize the Shapley–Shubik index for (3,2)simple games. Thus, we introduce a new axiom to prove the uniqueness of the extension of the Shapley–Shubik power index in this context. Moreover, we provide an analogous characterization for the Banzhaf index for (3,2)simple games, generalizing the four axioms for simple games and adding another property.

Measuring satisfaction and power in influence based decision systems
http://hdl.handle.net/2117/132016
Measuring satisfaction and power in influence based decision systems
Molinero Albareda, Xavier; Riquelme Csori, Fabián; Serna Iglesias, María José
We introduce collective decisionmaking models associated with influence spread under the linear threshold model in social networks. We define the oblivious and the nonoblivious influence models. We also introduce the generalized opinion leader–follower model (gOLF) as an extension of the opinion leader–follower model (OLF) proposed by van den Brink et al. (2011). In our model we allow rules for the final decision different from the simple majority used in OLF. We show that gOLF models are nonoblivious influence models on a twolayered bipartite influence digraph. Together with OLF models, the satisfaction and the power measures were introduced and studied. We analyze the computational complexity of those measures for the decision models introduced in the paper. We show that the problem of computing the satisfaction or the power measure is #Phard in all the introduced models even when the subjacent social network is a bipartite graph. Complementing this result, we provide two subfamilies of decision models in which both measures can be computed in polynomial time. We show that the collective decision functions are monotone and therefore they define an associated simple game. We relate the satisfaction and the power measures with the Rae index and the Banzhaf value of an associated simple game. This will allow the use of known approximation methods for computing the Banzhaf value, or the Rae index to their practical computation.
20190425T11:46:03Z
Molinero Albareda, Xavier
Riquelme Csori, Fabián
Serna Iglesias, María José
We introduce collective decisionmaking models associated with influence spread under the linear threshold model in social networks. We define the oblivious and the nonoblivious influence models. We also introduce the generalized opinion leader–follower model (gOLF) as an extension of the opinion leader–follower model (OLF) proposed by van den Brink et al. (2011). In our model we allow rules for the final decision different from the simple majority used in OLF. We show that gOLF models are nonoblivious influence models on a twolayered bipartite influence digraph. Together with OLF models, the satisfaction and the power measures were introduced and studied. We analyze the computational complexity of those measures for the decision models introduced in the paper. We show that the problem of computing the satisfaction or the power measure is #Phard in all the introduced models even when the subjacent social network is a bipartite graph. Complementing this result, we provide two subfamilies of decision models in which both measures can be computed in polynomial time. We show that the collective decision functions are monotone and therefore they define an associated simple game. We relate the satisfaction and the power measures with the Rae index and the Banzhaf value of an associated simple game. This will allow the use of known approximation methods for computing the Banzhaf value, or the Rae index to their practical computation.

On the uniqueness and analyticity in viscoelasticity with double porosity
http://hdl.handle.net/2117/131999
On the uniqueness and analyticity in viscoelasticity with double porosity
Bazarra, Noelia; Fernández, José Ramón; Leseduarte Milán, María Carme; Magaña Nieto, Antonio; Quintanilla de Latorre, Ramón
In this paper we analyze the system of equations that models the behaviour of materials with a double porous structure. We introduce dissipation mechanisms in both structures. We show existence, uniqueness and analyticity for the solutions of the system. As consequences, exponential stability and impossibility of localization for the solutions are obtained.
20190425T10:14:26Z
Bazarra, Noelia
Fernández, José Ramón
Leseduarte Milán, María Carme
Magaña Nieto, Antonio
Quintanilla de Latorre, Ramón
In this paper we analyze the system of equations that models the behaviour of materials with a double porous structure. We introduce dissipation mechanisms in both structures. We show existence, uniqueness and analyticity for the solutions of the system. As consequences, exponential stability and impossibility of localization for the solutions are obtained.

Bounds for the Nakamura number
http://hdl.handle.net/2117/131906
Bounds for the Nakamura number
Freixas Bosch, Josep; Kurz, Sascha
The Nakamura number is an appropriate invariant of a simple game to study the existence of social equilibria and the possibility of cycles. For symmetric (quota) games its number can be obtained by an easy formula. For some subclasses of simple games the corresponding Nakamura number has also been characterized. However, in general, not much is known about lower and upper bounds depending on invariants of simple, complete or weighted games. Here, we survey such results and highlight connections with other game theoretic concepts. © 2018, SpringerVerlag GmbH Germany, part of Springer Nature.
This is a postpeerreview, precopyedit version of an article published in Social choice and welfare. The final authenticated version is available online at: http://dx.doi.org/10.1007/s003550181164y.
20190424T10:22:40Z
Freixas Bosch, Josep
Kurz, Sascha
The Nakamura number is an appropriate invariant of a simple game to study the existence of social equilibria and the possibility of cycles. For symmetric (quota) games its number can be obtained by an easy formula. For some subclasses of simple games the corresponding Nakamura number has also been characterized. However, in general, not much is known about lower and upper bounds depending on invariants of simple, complete or weighted games. Here, we survey such results and highlight connections with other game theoretic concepts. © 2018, SpringerVerlag GmbH Germany, part of Springer Nature.

Qualitative results for a mixture of GreenLindsay thermoelastic solids
http://hdl.handle.net/2117/125861
Qualitative results for a mixture of GreenLindsay thermoelastic solids
Magaña Nieto, Antonio; Muñoz Rivera, Jaime E.; Naso, Maria Grazia; Quintanilla de Latorre, Ramón
We study qualitative properties of the solutions of the system of partial
differential equations modeling thermomechanical deformations for mixtures of thermoelastic solids when the theory of Green and Lindsay for the heat conduction is considered. Three dissipation mechanisms are proposed in the system: thermal dissipation, viscosity e ects on one constituent of the mixture and damping in the relative velocity of the two displacements of both constituents. First, we prove the existence and uniqueness of the solutions. Later we prove the exponential stability of
the solutions over the time. We use the semigroup arguments to establish our results
20181217T12:35:05Z
Magaña Nieto, Antonio
Muñoz Rivera, Jaime E.
Naso, Maria Grazia
Quintanilla de Latorre, Ramón
We study qualitative properties of the solutions of the system of partial
differential equations modeling thermomechanical deformations for mixtures of thermoelastic solids when the theory of Green and Lindsay for the heat conduction is considered. Three dissipation mechanisms are proposed in the system: thermal dissipation, viscosity e ects on one constituent of the mixture and damping in the relative velocity of the two displacements of both constituents. First, we prove the existence and uniqueness of the solutions. Later we prove the exponential stability of
the solutions over the time. We use the semigroup arguments to establish our results

A parameterization for a class of complete games with abstention
http://hdl.handle.net/2117/124189
A parameterization for a class of complete games with abstention
Freixas Bosch, Josep; Tchantcho, Bertrand; Proces Tsague, Bill
Voting games with abstention are voting systems in which players can cast not only yes and no vote, but are allowed to abstain. This paper centers on the structure of a class of complete games with abstention. We obtain, a parameterization that can be useful for enumerating these games, up to isomorphism. Indeed, any Icomplete game is determined by a vector of matrices with nonnegative integers entries. It also allows us determining whether a complete game with abstention is a strongly weighted (3, 2) game or not, and for other purposes of interest in game theory.
20181114T08:52:16Z
Freixas Bosch, Josep
Tchantcho, Bertrand
Proces Tsague, Bill
Voting games with abstention are voting systems in which players can cast not only yes and no vote, but are allowed to abstain. This paper centers on the structure of a class of complete games with abstention. We obtain, a parameterization that can be useful for enumerating these games, up to isomorphism. Indeed, any Icomplete game is determined by a vector of matrices with nonnegative integers entries. It also allows us determining whether a complete game with abstention is a strongly weighted (3, 2) game or not, and for other purposes of interest in game theory.

Exponential stability in type III thermoelasticity with microtemperatures
http://hdl.handle.net/2117/122813
Exponential stability in type III thermoelasticity with microtemperatures
Magaña Nieto, Antonio; Quintanilla de Latorre, Ramón
In this paper we consider the type III thermoelastic theory with microtemperatures. We study the time decay of the solutions and we prove that under suitable conditions for the constitutive tensors, the solutions decay exponentially. This fact is in somehow shocking because it differs from the behavior of the solutions in the classical model of thermoelasticity with microtemperatures
20181023T11:33:17Z
Magaña Nieto, Antonio
Quintanilla de Latorre, Ramón
In this paper we consider the type III thermoelastic theory with microtemperatures. We study the time decay of the solutions and we prove that under suitable conditions for the constitutive tensors, the solutions decay exponentially. This fact is in somehow shocking because it differs from the behavior of the solutions in the classical model of thermoelasticity with microtemperatures

Satisfaction and power in unanimous majority influence decision models
http://hdl.handle.net/2117/122635
Satisfaction and power in unanimous majority influence decision models
Molinero Albareda, Xavier; Riquelme Csori, Fabián; Serna Iglesias, María José
We consider decision models associated with cooperative influence games, the oblivious and the nonoblivious influence models. In those models the satisfaction and the power measures were introduced and studied. We analyze the computational complexity of those measures when the in
uence level is set to unanimity and the rule of decision is simple majority. We show that computing the satisfaction and the power measure in those systems are #Phard.
20181018T15:19:16Z
Molinero Albareda, Xavier
Riquelme Csori, Fabián
Serna Iglesias, María José
We consider decision models associated with cooperative influence games, the oblivious and the nonoblivious influence models. In those models the satisfaction and the power measures were introduced and studied. We analyze the computational complexity of those measures when the in
uence level is set to unanimity and the rule of decision is simple majority. We show that computing the satisfaction and the power measure in those systems are #Phard.

On the thermoelasticity with two porosities: asymptotic behaviour
http://hdl.handle.net/2117/122046
On the thermoelasticity with two porosities: asymptotic behaviour
Bazarra, Noelia; Fernández, José Ramón; Leseduarte Milán, María Carme; Magaña Nieto, Antonio; Quintanilla de Latorre, Ramón
In this paper we consider the onedimensional version of thermoelasticity with two porous structures and porous dissipation on one or both of them. We first give an existence and uniqueness result by means of semigroup theory. Exponential decay of the solutions is obtained when porous dissipation is assumed for each porous structure. Later, we consider dissipation only on one of the porous structures and we prove that, under appropriate conditions on the coefficients, there exists undamped solutions. Therefore, asymptotic stability cannot be expected in general. However,
we are able to give suitable sufficient conditions for the constitutive coefficients to guarantee the exponential decay of the solutions.
20181009T10:15:43Z
Bazarra, Noelia
Fernández, José Ramón
Leseduarte Milán, María Carme
Magaña Nieto, Antonio
Quintanilla de Latorre, Ramón
In this paper we consider the onedimensional version of thermoelasticity with two porous structures and porous dissipation on one or both of them. We first give an existence and uniqueness result by means of semigroup theory. Exponential decay of the solutions is obtained when porous dissipation is assumed for each porous structure. Later, we consider dissipation only on one of the porous structures and we prove that, under appropriate conditions on the coefficients, there exists undamped solutions. Therefore, asymptotic stability cannot be expected in general. However,
we are able to give suitable sufficient conditions for the constitutive coefficients to guarantee the exponential decay of the solutions.

On the stability in phaselag heat conduction with two temperatures
http://hdl.handle.net/2117/122033
On the stability in phaselag heat conduction with two temperatures
Magaña Nieto, Antonio; Miranville, Alain; Quintanilla de Latorre, Ramón
We investigate the wellposedness and the stability of the solutions for several Taylor approximations of the phaselag twotemperature equations.We give conditions on the parameters which guarantee
the existence and uniqueness of solutions as well as the stability and the instability of the solutions for each approximation
20181009T08:31:24Z
Magaña Nieto, Antonio
Miranville, Alain
Quintanilla de Latorre, Ramón
We investigate the wellposedness and the stability of the solutions for several Taylor approximations of the phaselag twotemperature equations.We give conditions on the parameters which guarantee
the existence and uniqueness of solutions as well as the stability and the instability of the solutions for each approximation