15771 research outputs found
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Arguing about Voting Rules
No full textWhen the members of a group have to make a decision, they can use a voting rule to aggregate their preferences. But which rule to use is a difficult question. Different rules have different properties, and social choice theorists have found arguments for and against most of them. These arguments are aimed at the expert reader, used to mathematical formalism. We propose a logic-based language to instantiate such arguments in concrete terms in order to help people understand the strengths and weaknesses of different voting rules. Our approach allows us to automatically derive a justification for a given election outcome or to support a group in arguing over which voting rule to use. We exemplify our approach with an in-depth study of the Borda rule.nonouirechercheInternationa
Robust capacity expansion of a network under demand uncertainty: a bi-objective approach
No full textThis paper deals with the problem of capacity expansion of a network under independent uncertain demands defined by interval sets. In this context, decisions about capacity expansion must be made before the demands are revealed. Standard robust models require the definition of an uncertainty domain and look for the minimum cost solution able to satisfy any demand within this domain. We propose, justify, and illustrate an alternative robust model based on a bi-objective formulation. Therefore, in addition to the cost criterion, we consider a second criterion, related to the Quality of Service, which measures the ability of a solution to handle any demand. The decision-maker can be interested in efficient solutions offering a compromise between these criteria. We study the complexity of the enumeration of the corresponding nondominated set, and propose exact and approximation algorithms.nonouirechercheInternationa
The subjective value of a life with Down syndrome: Evidence from amniocentesis decision
No full textUsing a simple theoretical decision model and an original database, we were able to elicit the distribution of the utility value of having a child with Down syndrome for a large sample of French pregnant women (n = 28,341) between 2003 and 2007. We found that, on a scale where the value of a fetal death is 0 and the value of a healthy child is 1, the mean value for a child with Down syndrome is about −0.6. Assuming that the policymaker used the same decision model as the women, we infer from the French amniocentesis reimbursement regulation an implicit social value for a child with Down syndrome of −2.5. We conclude from our study that the policymaker is more likely to prevent the birth of children with Down syndrome than French women themselves.nonouirechercheInternationa
On the Measurement of Cooperative Compatibility to Predict Meaning Variance
No full textComputer Supported Cooperative Work may rely on information technology in order to share information regardless where stakeholders are. Nevertheless, cooperative work needs more than just information sharing, notably because of meaning variance. Considering that during cooperative work the same information may have different meanings from one person to another, we propose an approach in order to predict meaning variance by measuring cooperative compatibility. We study the expectations individuals may have from their colleagues during a given cooperative work. Such study leads to the measurement of cooperative compatibility, which has been used to predict meaning variance. The calculation method proposed, as well as its relationships with meaning variance are discussed in this paper and currently tested within organizations.nonouirechercheInternationa
La discrimination des prix dans un cadre de concurrence spatiale
No full textLes modèles de concurrence spatiale à la Hotelling permettent de traiter simultanément deux éléments de la concurrence imparfaite : la différenciation des produits et la discrimination des prix. On montre qu'au-delà d'un certain degré de monopole, la discrimination des prix permet de maximiser les résultats de la firme, notamment lorsque les coûts sont élevés et les coûts marginaux faibles. Certaines productions qui exigent des coûts fixes élevés ne peuvent alors être engagés que si une politique discriminatoire est engagée. Les entreprises ont alors intérêt à se spécialiser dans les activités où elles disposent d'un degré de monopole suffisant pour pratiquer la discrimination.In spatial competition models « à la Hotelling », we can treat simultaneously of two components of imperfect competition : product differentiation and price discrimination. We show that beyond a certain degree of monopoly, price discrimination maximizes the outcome of the firm especially when fixed costs are high for low marginal costs. Some goods with high fixed costs are produced only when price discrimination is feasible. Then, firms have to choose activities where the degree of monopoly is enough for a price discrimination policy.nonouirechercheNationa
Intervention Research in Management
No full textAction research is a term used to describe a family of related approaches that integrate theory and action with a goal of addressing important organizational, community, and social issues together with those who experience them. It focuses on the creation of areas for collaborative learning and the design, enactment and evaluation of liberating actions through combining action and research, reflection and action in an ongoing cycle of cogenerative knowledge. While the roots of these methodologies go back to the 1940s, there has been a dramatic increase in research output and adoption in university curricula over the past decade. This is now an area of high popularity among academics and researchers from various fields - especially business and organization studies, education, health care, nursing, development studies, ... Intervention Research in management (IRM) shares a field-oriented methodology and an experimental logic with action research, but it differs from it by its basic assumptions about the essence and history ...nonouirechercheInternationa
Ranking Sets of Possibly Interacting Objects Using Shapley Extensions
No full textWe deal with the problem of how to extend a preference relation over a setX of “objects” to the set of all subsets of X. This problem has been carried out in the tradition of the literature on extending an order on a set to its power set with the objective to analyze the axiomatic structure of families of rankings over subsets. In particular, most of these approaches make use of axioms aimed to prevent any kind of interaction among the objects in X.In this paper, we apply coalitional games to study the problem of extending preferences over a finite set X to its power set 2x. A coalitional game can be seen as a numerical representation of a preference extension on 2x. We focus on a particular class of extensions on 2x such that the ranking induced by the Shapley value of each coalitional game representing an extension in this class, coincides with the original preference on X.Some properties of Shapley extensions are discussed, with the objective to justify and contextualize the application of Shapley extensions to the problem of ranking sets of possibly interacting objects.nonouirechercheInternationa
Enabling sleep mode in backbone IP-networks: A criticality-driven tradeoff
No full textThe energy consumption of network devices, and, as a consequence, of communication networks, is generally independent from their level of utilization, which results in awaste of energy when the network islightly loaded. Ideally the consumption of a network should be proportional to the amount of traffic it conveys. The most straightforward way to enforce such a proportionality between the network energy consumption and its utilization level, is to dynamically adapt the status of network devices to the load, forcing a subset of them to enter a sleep state during the low activity periods. We present in this paper an algorithm to dynamically put links into a sleep state, based on a cooperative-game approach, named “L-Game”. Our approach decides which links can be switched off based on a measure of the criticality of each link expressed as its Shapley value. This measure combines topological aspects and traffic conditions. Simulation results on real network scenarios show that our solution achieves a better trade off between energy saving and Traffic Engineering than other legacy approaches.nonouirechercheInternationa
Pédagogie économique
No full textLa cause semble entendue et pérenne. À un ordre économique et financier qui impose des « réformes structurelles » aussi douloureuses qu’indiscutables (plan quinquennal de réduction des dépenses publiques, rallongement de la durée de cotisations pour bénéficier de pensions de retraites ou d’indemnités chômage, baisse des cotisations sociales afin d’améliorer le coût du travail et la compétitivité, etc.), répond le souci d’en expliquer la teneur et la nécessité, d’envoyer des messages clairs à l’opinion, bref d’offrir davantage de pédagogie à un public qu’il suffirait de convaincre de leur bien-fondé.nonouirechercheNationa