Showing papers by "Paris West University Nanterre La Défense published in 1997"
TL;DR: In this article, a group-symmetry analysis of the low-lying levels of the spin-1/2 kagom\'e Heisenberg antiferromagnet is performed for small samples up to $N=27.
Abstract: A group-symmetry analysis of the low-lying levels of the spin-1/2 kagom\'e Heisenberg antiferromagnet is performed for small samples up to $N=27$. This approach allows one to follow the effect of quantum fluctuations when the sample size increases. The results contradict the scenario of ``order by disorder'' which has been advanced on the basis of large-$S$ calculations. A large enough second-neighbor ferromagnetic exchange coupling is needed to stabilize the $\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}$ pattern: the finite-size analysis indicates a quantum critical transition at a nonzero coupling.
256 citations
TL;DR: In this article, the authors evaluate the consequences on productivity and employment of the large increase in profit sharing in France since 1986, and show that profit-sharing schemes improve productivity, but have ambiguous effects on employment.
82 citations
TL;DR: Otlet's project of a colossal Bibliopolis contrasts very much with the position of Georges Bataille (a French writer who was librarian at the Bibliotheque Nationale from 1922 to 1942) who denounced the totalitarian threat of centralized monumental structures as discussed by the authors.
Abstract: According to Paul Otlet, in order to face the worldwide interdependence which was evidenced in the First World War, we need an international center for the storage and dissemination of knowledge: The Mundaneum (1928). To study this utopian project is to study how positivism, centralism, and monumentalism have determined Otlet's international perspective. His project of a colossal Bibliopolis contrasts very much with the position of Georges Bataille (a French writer who was librarian at the Bibliotheque Nationale from 1922 to 1942) who denounced the totalitarian threat of centralized monumental structures. But we show that, in spite of his centralism and his monumentalism, Paul Otlet foresaw our world-wide networked environment and that his three-dimensional conception of information can be still useful for developing Computer Assisted Palaces of Memory connected to International Virtual Libraries. © 1997 John Wiley & Sons, Inc.
36 citations
TL;DR: In this article, the authors give a detailed analysis of the new provisions, highlighting those items which may be the subject of further developments, but also pointing out the shortcomings of new provisions.
Abstract: ** Director, Observatoire social européen Employment was not initially on the programme of the intergovernmental conference. However, it gradually came to be seen as a priority on the negotiating agenda. We will give a detailed analysis of the new provisions, highlighting those items which may be the subject of further developments, but also pointing out the shortcomings of the new provisions. In point of fact, employment came to be high on the agenda in the absence of progress in other areas, in particular, the CFSP (Common Foreign and Security Policy) and institutional reform. The six articles which make up this title stem from the dynamic initiated by the 1993 white paper ’Growth, competitiveness, employment’, as well as from the five objectives defined at the Council of Essen (1994). (For a dynamic view of Community employment policy, cf. Goetschy 1997; Pochet 1997). On the other hand, despite pressure from France’s
17 citations
01 Jan 1997
TL;DR: In this article, the authors focus on one-tail scale invariance in the stock market, and defer the analysis of two tails scale-invariant economic phenomena to another lecture.
Abstract: “Scale invariance” is not a common expression in economics, and expressions like “self similarity” or “self affinity” are scarcely used. Even “stable non gaussian laws” (or “Levy laws”, or “Pareto-Levy” laws) and “fractals”, introduced in economics by B. Mandelbrot [1–2], remain relativily unheard outside financial markets and research centers devoted to finance. Actually, history of economics thought is full of scale invariant distributions, but under another name: Pareto. This famous sociologist and economist of the end of the XIXth century found numerous examples of power laws in income size-distributions [3]. Hence the common name “Pareto” for such a type of economic distributions. Nevertheless, income distributions are not the unique family of scale invariant economic distributions. Firm sizes and assets sizes [4–6], industrial insurance claim sizes [7–9], economic damages due to natural catastrophes, such as hurricanes or earthquakes [10–11], stock market prices fluctuations in the short run and in the long run [2, 6, 12–14] etc. display either one tail with a power law (for obvious reasons most economic size-distributions can only take a positive value) or two tails (all stock market prices, since they have positive and negative variations). In that case they have either a power law on both tails, a typical behavior of all stable non gaussian distributions fitting the whole distribution, or a gaussian law fitting the whole distribution. As regards stock market, scale invariance is not a new scientific discovery. Bachelier [12] in his now famous thesis on Paris “Bourse” settled in 1900 the founding stone of brownian motion, the prototype of gaussian scale invariance. In order to sort out the origins and implications of scale invariance in economics, we will restrict our analysis to one-tail economic phenomena, deferring the analysis of two tails scale invariant economic phenomena to another lecture.
13 citations
TL;DR: These extensions will allow us to define new notions of equilibria and see how the outcomes change when communication between players is allowed, or when they are given some kind of preplay information.
Abstract: The purpose of this presentation is to introduce models of extension of games with preplay or intraplay information and communication. These extensions will allow us to define new notions of equilibria. The relevant question is to see how the outcomes change when communication between players is allowed, or when they are given some kind of preplay information.
8 citations
01 Jan 1997
TL;DR: Repeated games provide a bridge between cooperative and non cooperative game theory: folk-theorem-like results deal with the relation between feasible payoffs in a one shot game and equilibrium payoff in the corresponding repeated game.
Abstract: Cooperative game theory deals with feasible outcomes, whereas non cooperative game theory is concerned with strategic equilibrium. Repeated games provide a bridge between these two theories: folk-theorem-like results deal with the relation between feasible payoffs in a one shot game and equilibrium payoffs in the corresponding repeated game.
6 citations
01 May 1997
TL;DR: In this paper, auteurs exposent brievement les resultats de la deuxieme campagne de fouille de l'eglise Velika Gospa (S.Maria Alta) pres de Bale en Istrie.
Abstract: Les auteurs exposent brievement les resultats de la deuxieme campagne de fouille de l'eglise Velika Gospa (S.Maria Alta) pres de Bale en Istrie. Cette campagne a permis de degager l’ensemble du collateral nord, la moitie orientale du vaisseau central, ainsi que l’Ouest de l'edifice entre la facade primitive et celle de l’eglise baroque. On a ainsi pu restituer l’integralite du premier bâtiment, constater sa contraction medievale, et vraisemblablement la construction d’un clocher dans son angle sud-ouest. La definition precise de ces phases ne sera possible qu'apres des recherches ulterieures. La decouverte de plusieurs phases de mobilier liturgique et surtout celle des grands chapiteaux des colonnades des nefs, probablement attribuables a la 2 moitie du VIIIe ou au debut du IXe s., font de l’eglise S.Maria Alta un des plus importants edifices hautmedievaux de cette partie de l’Europe.
1 citations
1 citations