La Chronica Naiarensis : d'un néo-gothisme astur-léonais à un néo-gothisme castillan

International audienceLa Chronica Naiarensis posee el doble interés de heredar la historiografía astur-leonesa y su ideología política, y también de defender el condado y luego el reino de Castilla. Mientras las Crónicas Asturianas y la Historia Silense, sus principales fuentes, se basaban en una ideología neo-visigótica, o sea en un principio de restauración étnica y genealógica - por el reino de León - del antiguo imperio de los Godos que desapareció en el año 711, la Najerense se apropia del mito y lo asimila a la génesis del reino de Castilla. En el contexto histórico de finales del siglo XII en que Castilla experimenta una gran ascensión política, los autores de la crónica reivindican una herencia más ideológica y conceptual. Este neo-hispanismo tiende a justificar la vocación de Castilla a un poder pan-hispánico.La Chronica Naiarensis possède ce double intérêt d'hériter de l'historiographie astur-léonaise et de son idéologie politique, mais aussi de défendre le comté puis le royaume de Castille. Alors que les Chroniques asturiennes et l'Historia Silense, ses sources principales, se fondaient sur une idéologie néo-wisigothique, c'est-à-dire sur un principe de restauration ethnique et généalogique - par le royaume de León - de l'antique empire des Wisigoths qui périt en 711, la Naiarensis s'approprie le mythe et l'assimile à la genèse du royaume de Castille. Dans un contexte historique où la Castille connaît une forte ascension politique, les auteurs de la chronique revendiquent un héritage davantage idéologique et conceptuel. Ce néo-hispanisme tend à démontrer la vocation de la Castille à un pouvoir pan-hispanique

Quelle stratégie de gestion des risques côtiers pour l'union européenne

L'Union européenne a conçu et mis en oeuvre, ces dernières décennies, de nombreux instruments juridiques de conservation de l'environnement marin et littoral et d'encadrement des activités qui s'y déploient, contribuant ainsi à une première prise en considération des risques côtiers. Plusieurs politiques de l'Union ont servi de cadre à cette action avec l'inconvénient de la dispersion et du cloisonnement qui caractérise les approches sectorielles. Le Livre vert sur une politique maritime de l'Union se propose, désormais, de donner à l'ensemble la cohérence et la lisibilité indispensables à une véritable stratégie de gestion des risques côtiers et de garantir les meilleures conditions d'application possibles. Après avoir analysé la notion de risques côtiers et décliné les instruments juridiques existants, l'auteur propose les grands axes stratégiques d'une gestion européenne des risques, levier d'un aménagement intégré des zones côtières

Intentionality: Transparent, Translucent, and Opaque

Exploring intentionality from an externalist perspective, I distinguish three kinds of intentionality in the case of seeing, which I call transparent, translucent, and opaque respectively. I then extend the distinction from seeing to knowing, and then to believing. Having explicated the three-fold distinction, I then critically explore some important consequences that follow from granting that there are transparent and translucent intentional states and these intentional states are mental states. These consequences include: first, that existential opacity is neither the mark of intentionality nor of the mental; second, that Sellars has not shown that all intentionality is non-relational; third, that a key Quinean argument for semantic indeterminacy rests on a false premise; fourth, that perceptual experience is intentional on Alston’s Theory of Appearing; fifth, that either some mental causation is more than internal physiological causation or some mental states are epiphenomenal

Secure Refinements of Communication Channels

It is a common practice to design a protocol (say Q) assuming some secure channels. Then the secure channels are implemented using any standard protocol, e.g. TLS. In this paper, we study when such a practice is indeed secure. We provide a characterization of both confidential and authenticated channels. As an application, we study several protocols of the literature including TLS and BAC protocols. Thanks to our result, we can consider a larger number of sessions when analyzing complex protocols resulting from explicit implementation of the secure channels of some more abstract protocol Q

Secure refinements of communication channels

It is a common practice to design a protocol (say Q) assuming some secure channels. Then the secure channels are implemented using any standard protocol, e.g. TLS. In this paper, we study when such a practice is indeed secure. We provide a characterization of both confidential and authenticated channels. As an application, we study several protocols of the literature including TLS and BAC protocols. Thanks to our result, we can consider a larger number of sessions when analyzing complex protocols resulting from explicit implementation of the secure channels of some more abstract protocol Q

Interlaced spin grating for optical wave filtering

Interlaced Spin Grating is a scheme for the preparation of spectro-spatial periodic absorption gratings in a inhomogeneously broadened absorption profile. It relies on the optical pumping of atoms in a nearby long-lived ground state sublevel. The scheme takes advantage of the sublevel proximity to build large contrast gratings with unlimited bandwidth and preserved average optical depth. It is particularly suited to Tm-doped crystals in the context of classical and quantum signal processing. In this paper, we study the optical pumping dynamics at play in an Interlaced Spin Grating and describe the corresponding absorption profile shape in an optically thick atomic ensemble. We show that, in Tm:YAG, the diffraction efficiency of such a grating can reach 18.3% in the small angle, and 11.6% in the large angle configuration when the excitation is made of simple pulse pairs, considerably outperforming conventional gratings.Comment: 11 pages, 13 figures in Physical Review A, 201

Cayley lattices of finite Coxeter groups are bounded

AbstractAn interval doubling is a constructive operation which applies on a poset P and an interval I of P and constructs a new “bigger” poset P′=P[I] by replacing in P the interval I with its direct product with the two-element lattice. The main contribution of this paper is to prove that finite Coxeter lattices are bounded, i.e., that they can be constructed starting with the two-element lattice by a finite series of interval doublings.The boundedness of finite Coxeter lattices strengthens their algebraic property of semidistributivity. It also brings to light a relation between the interval doubling construction and the reflections of Coxeter groups.Our approach to the question is somewhat indirect. We first define a new class HH of lattices and prove that every lattice of HH is bounded. We then show that Coxeter lattices are in HH and the theorem follows. Another result says that, given a Coxeter lattice LW and a parabolic subgroup WH of the finite Coxeter group W, we can construct LW starting from WH by a series of interval doublings. For instance the lattice, associated with An, of all the permutations on n+1 elements is obtained from An−1 by a series of interval doublings. The same holds for the lattices associated with the other infinite families of Coxeter groups Bn, Dn and I2(n)

Study of Observer Variability in Modern Display Colorimetry: Comparison of CIE 2006 Model and 10° Standard Observer

International audienceThis paper compares CIE 2006 model predictions and the 1964 10° standard colorimetric observer with the average observer data from three distinct subgroups of 47 Stiles-Burch observers formed on the basis of observer ages. For two of these subgroups, the long-wave sensitive (x-) color matching functions obtained from the CIE06 model did not accurately predict the intra-group average observer functions. In terms of display color perception, the prediction error is reflected in the longer wavelengths of the color spectrum. In contrast, the short-wave sensitive (z-) function of the 10° standard observer showed significant deviations from the intra-group average observer for all three subgroups

Modern displays: Why we see different colors, and what it means?

International audienceOne of the basic tenets of conventional applied colorimetry is that the whole population of color normal observers can be represented by a single "standard" observer with reasonable accuracy. The 1964 CIE standard colorimetric observer has indeed served us well in all industrial color imaging applications, until recently. With the proliferation of modern wide-gamut displays with narrow-band primaries, color scientists and engineers face a new challenge. Various recent studies, including those by the current authors, have shown that the color perception on such displays varies significantly among color normal observers. Conventional colorimetry has no means to predict this variation. In this paper, we explore this problem by summarizing the results from an ongoing study, and explain the practical significance of this issue in the context of display applications