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Microeconomie : Comportements des agents et concurrence parfaite
No full textCe manuel présente l'essentiel de ce que doit savoir un étudiant de licence, de bachelor ou de prépas sur les théories du consommateur et du producteur en concurrence pure et parfaite. Il explique notamment les courbes d’indifférences, le taux marginal de substitution (TMS), le travail, l’épargne, les demandes de biens, la fonction de production, les coûts, la maximisation du profit, la fonction d’offre, l’équilibre de la firme…Conçu pour faciliter aussi bien l’apprentissage que la révision, cet ouvrage de microéconomie s’appuie sur :• 14 chapitres synthétiques ;• le raisonnement marginaliste au coeur de l’apprentissage de la microéconomie ;• une centaine d’exercices avec des corrigés détaillés car la microéconomie ne se comprend qu’en la pratiquant ;• une plateforme numérique (eText) avec des éléments supplémentaires d’approfondissement et d’entraînement.Le livre donne accès à des ressources numériques exclusives sur votre eText :• la version en ligne de tous les chapitres de l’ouvrage ;• deux chapitres supplémentaires d’introduction sur les notions d’équilibres et d’optimalités ;• des annexes mathématiques à la présentation simple sur les méthodes de résolution, le Lagrangien, les dérivées ;• une partie des corrigés des exercices du livre ;• des exercices corrigés supplémentaires ;• de nombreux compléments d’approfondissement avec applications corrigées.nonouinon-rechercheNationa
Logic, Language, and Computation, 7th International Tbilisi Symposium on Logic, Language, and Computation, TbiLLC 2007, Tbilisi, Georgia, October 1-5, 2007. Revised Selected Papers
No full textouinonouirechercheInternationa
Completeness in differential approximation classes
No full textWe study completeness in differential approximability classes. In differential approximation, the quality of an approximation algorithm is the measure of both how far is the solution computed from a worst one and how close is it to an optimal one. The main classes considered are DAPX, the differential counterpart of APX, including the NP optimization problems approximable in polynomial time within constant differential approximation ratio and the DGLO, the differential counterpart of GLO, including problems for which their local optima guarantee constant differential approximation ratio. We define natural approximation preserving reductions and prove completeness results for the class of the NP optimization problems (class NPO), as well as for DAPX and for a natural subclass of DGLO. We also define class 0-APX of the NPO problems that are not differentially approximable within any ratio strictly greater than 0 unless P = NP. This class is very natural for differential approximation, although has no sense for the standard one. Finally, we prove the existence of hard problems for a subclass of DPTAS, the differential counterpart of PTAS, the class of NPO problems solvable by polynomial time differential approximation schemata.ouinonouirechercheInternationa
Reasoning under inconsistency: the forgotten connective
No full textIn many frameworks for reasoning under inconsistency, it is implicitly assumed that the formulaefrom the belief base are connected using a weakform of conjunction. When it is consistent, a beliefbase B = f'1; : : : ; 'ng, where the 'i are proposi-tional formulae, is logically equivalent to the basef'1 ^ : : : ^ 'ng. However, when it is not consistent, both bases typically lead to different conclusions. This illustrates the fact that the commaused in base B has to be considered as an additional, genuine connective, and not as a simple conjunction. In this work we define and investigate apropositional framework with such a "comma con-nective". We give it a semantics and show how itgeneralizes several approaches for reasoning frominconsistent beliefs.ouinonouirechercheInternationa
Exponential approximation schemata for some network design problems
No full textWe study approximation of some well-known network design problems such as traveling salesman problem (for both minimization and maximization versions) and min steiner tree, by moderately exponential algorithms. The general goal of the issue of moderately exponential approximationis to catch-up on polynomial inapproximability, by providing algorithms achieving, with worst-caserunning times importantly smaller than those needed for exact computation, approximation ratiosunachievable in polynomial time.ouinonouirechercheInternationa
Possible winners when new candidates are added : the case of scoring rules
No full textIn some voting situations, some new candidates may show up in the course of the process. In this case, we may want to determine which of the initial candidates are possible winners, given that a fixed number k of new candidates will be added. Focusing on scoring rules, we give complexity results for the above possible winner problem.ouinonouirechercheInternationa
A General Elicitation-Free Protocol for Allocating Indivisible Goods
No full textWe consider the following sequential allocation process. A benevolent central authority has to allocate a set of indivisible goods to a set of agents whose preferences it is totally ignorant of. We consider the process of allocating objects one after the other by designating an agent and asking her to pick one of the objects among those that remain. The problem consists in choosing the “best” sequence of agents, according to some optimality criterion. We assume that agents have additive preferences over objects. The choice of an optimality criterion depends on three parameters: how utilities of objects are related to their ranking in an agent’s preference relation; how the preferences of different agents are correlated; and how social welfare is defined from the agents’ utilities. We address the computation of a sequence maximizing expected social welfare under several assumptions. We also address strategical issues.ouinonouirechercheInternationa
Liquidity Contagion : A Look at Emerging Markets
No full textEmerging economies have passed an important stress test during the period 2008-09 andare now the key drivers for global growth of the world economy. Financial markets are todayso inter connected that they are fragile to contagion. The issue of financial contagion washistorically concerning Emerging Markets (EM). These latter attract foreign investors andmassive investments funds in - and out - flows on very short horizons can be a source of contagion effects between markets. The analysis of the sovereign debt markets and particularlyrelated CDS markets is of interest since it is at the very center of a new phenomenon: banksare not any more the main source of systemic risk but sovereign economies are. As foreigninvestors represent the most of the volume traded, capital flows in these markets should also impact FX market. Their analysis is thus also central to this study. Indeed, the mainrisk for an asset manager is to get stuck with unwanted sovereign debt due to a dry up ofmarket liquidity. The main contribution of this paper is the analysis of contagion looking atcommon markets liquidity problems to detect funding liquidity problems. We use the CreditDefault Swap bond spread basis and the deviations from the Covered Interest Parity as liquidity measures respectively for sovereign debt and FX markets. Moreover, we distinguishinterdependence and pure contagion using a state-space model with a time - varying volatilityspecification and we apply it to both returns and liquidity indicators.ouinonouirechercheInternationa
An emergency management model for a wireless sensor network problem
No full textWe present a natural wireless sensor network problem, which we model as a probabilisticversion of the min dominating set problem. We show that this problem, being a generalization of the classical min dominating set, is NP-hard, even in bipartite graphs. We firststudy the complexity of probabilistic min dominating set in graphs where min dominatingset is polynomial, mainly in trees and paths and then we give some approximationresults for it.nonnonouirechercheInternationa