L'archive ouverte pluridisciplinaire HAL , est destinée au dépôt et à la diffusion d'articles scientifiques de niveau recherche, publiés ou non, et de thèses, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Derniers Dépôts
Chimie
Économie et finance quantitative
Informatique
Mathématiques
Physique
Planète et Univers
Science non linéaire
Sciences cognitives
Sciences de l'environnement
Sciences de l'Homme et Société
Sciences de l'ingénieur
Sciences du Vivant
Statistiques
An in situ experiment has been carried out inbioturbated Mediterranean coastal marine sediments (Gulfof Fos) in order to study the influence of hydrocarbons ondenitrification after 1, 4 and 6 months. In theabsence of hydrocarbons in the control sediments, the presenceof macrofauna stimulated denitrificationby 160%. This stimulation is induced by sediment reworkingthat favours both direct NO-3 supply fromthe water column and the penetration of O{2}, which in turnstimulated nitrification, the other source ofNO-3 in sediment. The presence of hydrocarbons in theexperimental sediments either stimulated orinhibited the denitrification. The denitrification response tothe presence of hydrocarbon is dependent onthe quantity of matter buried by the macrofauna activity. Insmall quantities, the organic matter relatedto hydrocarbons 120% enhanced the denitrification compared tothe controls. On the other hand, whenburied hydrocarbon concentrations were higher (>100 mgsaturated hydrocarbon fraction kg-1 drysediment), the denitrification was inhibited.On the basis of the results obtained, a descriptive model ofthe patterns of denitrification in relation to the presence ofmacrofauna and the distribution of hydrocarbons in sediments is proposed.
Room temperature reversible C-H activation mediated by a designed diphosphine platinum complex is presented. These findings are demonstrated through mechanistic studies involving kinetics, isotopic effects, and corroborated by DFT calculations. The coupling between two unactivated aromatic derivatives is also demonstrated.
The aim of this paper is to provide an overview of the developments in nuclear track methodology as published in the proceedings of the last ten meetings of the International Conference on Nuclear Tracks in Solids (ICNTS) from the Marburg (Germany) conference in 1990 to the Bologna (Italy) conference of 2008. Nuclear Tracks Methodology (NTM) examines the effects of the interaction between charged particles and solid materials and presents several desirable characteristics: the detectors can easily be cut into a size appropriate for any application and can be used in locations for which other radiation detectors are not suitable; the etching and reading instrumentation is relatively simple; there is a quasiinsensibility to gamma radiation for reasonable dose exposures (typically <1 kGy); after chemical etching the information recorded on the detector material is essentially permanent; and, finally, the system involves relatively low costs. These characteristics have contributed to the importance of NTM for radiation detection in an immense number of applications across a wide range of scientific and technological fields. This paper reviews the new ideas, topics, materials and applications related to NTM that have been presented over the past ten ICNTS meetings from 1990 to 2008, and analyzes the evolution of various topics. One could argue that the conferences themselves have been an important source of new ideas and applications for the nuclear track research community. Two important observations arise from this review. The first is that the contributions of the past ten international conferences can be conveniently classified into 12 categories. The second is that the number of papers published varied widely from conference to conference. Several factors contributed: the variation in the number of conference participants, the interests of local participants (who account for a disproportionate number of conference participants), the location of the conference, and the appearance of new international conferences devoted to topics similar to those covered by the ICNTS.
We present a mathematical study of the order book as a multidimensional continuous- time Markov chain where the order ow is modeled by independent Poisson processes. Our aim is to bridge the gap between the microscopic description of price formation (agent- based modeling), and the Stochastic Di erential Equations approach used classically to describe price evolution at macroscopic time scales. To do this, we rely on the theory of in nitesimal generators and Foster-Lyapunov stability criteria for Markov chains. We motivate our approach using an elementary example where the spread is kept constant (\perfect market making"). Then we compute the in nitesimal generator associated with the order book in a general setting, and link the price dynamics to the instantaneous state of the order book. In the last section, we prove that the order book is ergodic| in particular it has a stationary distribution|that it converges to its stationary state exponentially fast, and that the large-scale limit of the price process is a Brownian motion.
In this paper, we consider a discrete time economy where we assume that the short term interest rate follows a quadratic term structure of a regime switching asset process. The possible non-linear structure and the fact that the interest rate can have different economic or financial trends justify the interest of Regime Switching Quadratic Term Structure Model (RS-QTSM). Indeed, this regime switching process depends on the values of a Markov chain with a time dependent transition probability matrix which can well captures the different states (regimes) of the economy. We prove that under this modelling that the conditional zero coupon bond price admits also a quadratic term structure. Moreover, the stochastic coefficients which appear in this decomposition satisfy an explicit system of coupled stochastic backward recursions.
In this note, we cast a Hawkes process-based order book model into a markovian setting, and using techniques from the theory of Markov chains and stochastic stability [16], show that the order book is stable and leads to a di usive price limit at large time scales.
Fact checking and data journalism are currently strong trends. The sheer amount of data at hand makes it difficult even for trained professionals to spot biased, outdated or simply incorrect information. We propose to demonstrate FactMinder, a fact checking and analysis assistance application. SIGMOD attendees will be able to analyze documents using FactMinder and experience how background knowledge and open data repositories help build insightful overviews of current topics.
This paper introduces a simple formalism for dealing with deterministic, non- deterministic and stochastic cellular automata in an unified and composable manner. This formalism allows for local probabilistic correlations, a feature which is not present in usual definitions. We show that this feature allows for strictly more behaviors (for instance, number conserving stochastic cellular automata require these local probabilistic correlations). We also show that several problems which are deceptively simple in the usual definitions, become undecidable when we allow for local probabilistic correlations, even in dimension one. Armed with this formalism, we extend the notion of intrinsic simulation between deterministic cellular automata, to the non-deterministic and stochas- tic settings. Although the intrinsic simulation relation is shown to become undecidable in dimension two and higher, we provide explicit tools to prove or disprove the existence of such a simulation between any two given stochastic cellular automata. Those tools rely upon a characterization of equality of stochastic global maps, shown to be equivalent to the existence of a stochastic coupling between the random sources. We apply them to prove that there is no universal stochastic cellular automaton. Yet we provide stochastic cellular automata achieving optimal partial universality, as well as a universal non-deterministic cellular automaton.
We introduce the \emph{resource control cube}, a system consisting of eight intuitionistic lambda calculi with either implicit or explicit control of resources and with either natural deduction or sequent calculus. The four calculi of the cube that correspond to natural deduction have been proposed by Kesner and Renaud and the four calculi that correspond to sequent lambda calculi are introduced in this paper. The presentation is parameterized with the set of resources (weakening or contraction), which enables a uniform treatment of the eight calculi of the cube. The simply typed resource control cube, on the one hand, expands the Curry-Howard correspondence to intuitionistic natural deduction and intuitionistic sequent logic with implicit or explicit structural rules and, on the other hand, is related to substructural logics. We propose a general intersection type system for the resource control cube calculi. Our main contribution is a characterisation of strong normalisation of reductions in this cube. First, we prove that typeability implies strong normalisation in the ''natural deduction base" of the cube by adapting the reducibility method. We then prove that typeability implies strong normalisation in the ''sequent base" of the cube by using a combination of well-orders and a suitable embedding in the ''natural deduction base". Finally, we prove that strong normalisation implies typeability in the cube using head subject expansion. All proofs are general and can be made specific to each calculus of the cube by instantiating the set of resources.
We introduce the \emph{resource control cube}, a system consisting of eight intuitionistic lambda calculi with either implicit or explicit control of resources and with either natural deduction or sequent calculus. The four calculi of the cube that correspond to natural deduction have been proposed by Kesner and Renaud and the four calculi that correspond to sequent lambda calculi are introduced in this paper. The presentation is parameterized with the set of resources (weakening or contraction), which enables a uniform treatment of the eight calculi of the cube. The simply typed resource control cube, on the one hand, expands the Curry-Howard correspondence to intuitionistic natural deduction and intuitionistic sequent logic with implicit or explicit structural rules and, on the other hand, is related to substructural logics. We propose a general intersection type system for the resource control cube calculi. Our main contribution is a characterisation of strong normalisation of reductions in this cube. First, we prove that typeability implies strong normalisation in the ''natural deduction base" of the cube by adapting the reducibility method. We then prove that typeability implies strong normalisation in the ''sequent base" of the cube by using a combination of well-orders and a suitable embedding in the ''natural deduction base". Finally, we prove that strong normalisation implies typeability in the cube using head subject expansion. All proofs are general and can be made specific to each calculus of the cube by instantiating the set of resources.
We consider the large time behavior of solutions to defocusing nonlinear Schrodinger equation in the presence of a time dependent external potential. The main assumption on the potential is that it grows at most quadratically in space, uniformly with respect to the time variable. We show a general exponential control of first order derivatives and momenta, which yields a double exponential bound for higher Sobolev norms and momenta. On the other hand, we show that if the potential is an isotropic harmonic potential with a time dependent frequency which decays sufficiently fast, then Sobolev norms are bounded, and momenta grow at most polynomially in time, because the potential becomes negligible for large time: there is scattering, even though the potential is unbounded in space for fixed time.
We describe the spectral theory of the adjacency operator of a graph which is isomorphic to homogeneous trees at infinity. Using some combinatorics, we reduce the problem to a scattering problem for a finite rank perturbation of the adjacency operator on an homogeneous tree. We developp this scattering theory using the classical recipes for Schrödinger operators in Euclidian spaces.
The origin of the observed acceleration of the expansion of the universe is a major problem of modern cosmology and theoretical physics. Simple estimations of the contribution of vacuum to the density energy of the universe in quantum field theory are known to lead to catastrophic large values compared to observations. Such a contribution is therefore generally not regarded as a viable source for the acceleration of the expansion. In this letter we propose that the vacuum contribution actually provides a small positive value to the density energy of the universe. The underlying mechanism is a manifestation of the quantum nature of the gravitational field, through a Casimir-like effect from an additional compact dimension of space. A key ingredient is to assume that only modes with wavelength shorter than the Hubble length contribute to the vacuum. Such a contribution gives a positive energy density, has a Lorentz invariant equation of state in the usual 4D spacetime and hence can be interpreted as a cosmological constant. Its value agrees with observations for a radius of a 5th extra dimension given by $35\,\mu$m. This implies a modification of the gravitational inverse square law around this scale, close but below existing limits from experiments testing gravity at short range.
The Josephson effect describes the flow of supercurrent in a weak link, such as a tunnel junction, nanowire, or molecule, between two superconductors. It is the basis for a variety of circuits and devices, with applications ranging from medicine to quantum information. Currently, experiments using Josephson circuits that behave like artificial atoms are revolutionizing the way we probe and exploit the laws of quantum physics. Microscopically, the supercurrent is carried by Andreev pair states, which are localized at the weak link. These states come in doublets and have energies inside the superconducting gap. Existing Josephson circuits are based on properties of just the ground state of each doublet and so far the excited states have not been directly detected. Here we establish their existence through spectroscopic measurements of superconducting atomic contacts. The spectra, which depend on the atomic configuration and on the phase difference between the superconductors, are in complete agreement with theory. Andreev doublets could be exploited to encode information in novel types of superconducting qubits.
A bosonic analogue of the fractional quantum Hall eff ect occurs in rapidly rotating trapped Bose gases: There is a transition from uncorrelated Hartree states to strongly correlated states such as the Laughlin wave function. This physics may be described by eff ective Hamiltonians with delta interactions acting on a bosonic N-body Bargmann space of analytic functions. In a previous paper [N. Rougerie, S. Serfaty, J. Yngvason, Phys. Rev. A 87, 023618 (2013)] we studied the case of a quadratic plus quartic trapping potential and derived conditions on the parameters of the model for its ground state to be asymptotically strongly correlated. This relied essentially on energy upper bounds using quantum Hall trial states, incorporating the correlations of the Bose-Laughlin state in addition to a multiply quantized vortex pinned at the origin. In this paper we investigate in more details the density of these trial states, thereby substantiating further the physical picture described in [N. Rougerie, S. Serfaty, J. Yngvason, Phys. Rev. A 87, 023618 (2013)], improving our energy estimates and allowing to consider more general trapping potentials. Our analysis is based on the interpretation of the densities of quantum Hall trial states as Gibbs measures of classical 2D Coulomb gases (plasma analogy). New estimates on the mean- field limit of such systems are presented.
The Korba aquifer on the east coast of Cape Bon has been overexploited since the 1960s with a resultant reversal of the hydraulic gradient and a degradation of the quality due to seawater intrusion. In 2008, the authorities introduced integrated water resources planning based on a managed aquifer recharge with treated wastewater. Water quality monitoring was implemented in order to determine the different system components and trace the effectiveness of the artificial recharge. Groundwater samples taken from recharge control piezometers and surrounding farm wells were analyzed for their chemical contents, for their boron isotopes, a proven tracer of groundwater salinization and domestic sewage, and their carbamazepine content, an anti-epileptic known to pass through wastewater treatment and so recognized as a pertinent tracer of wastewater contamination. The system equilibrium was permanently disturbed by the different temporal dynamics of continuous processes such as cation exchange, and by threshold processes linked to oxidation-reductive conditions. The boron isotopic compositions significantly shifted back-and-forth due to mixing with end-members of various origins. Under the variable contribution of meteoric recharge, the Plio-Quaternary groundwater (δ11B of 35-40.6‰, a mean B concentration of 30 µmol/L, no carbamazepine, n=7) was subject to seawater intrusion that induced a high δ11B level (δ11B of 41.5-48.0‰, a mean B concentration of 36 µmol/L, and n=8). Fresh groundwater (δ11B of 19.89‰, B concentration of 2.8 µmol/L, no carbamazepine) was detected close to the recharge site and may represent the deep Miocene pole which feeds the upper Plio-Quaternary aquifer. The managed recharge water (δ11B of 10.67-13.8‰, n=3) was brackish and of poor quality with a carbamazepine content showing a large short term variability with an average daily levels of 328 ± 61 ng/L. A few piezometers in the vicinity of the recharge site gradually acquired a B isotopic composition close to the wastewater signature and showed an increasing carbamazepine content (from 20 to 910 ng/L). The combination of boron isotopic signatures with boron and carbamazepine contents is a useful tool to assess sources and mixing of treated wastewaters in groundwaters. Effluent quality needs to be greatly improved before injection to prevent further degradation of groundwater quality.
The origin of the observed acceleration of the expansion of the universe is a major problem of modern cosmology and theoretical physics. Simple estimations of the contribution of vacuum to the density energy of the universe in quantum field theory are known to lead to catastrophic large values compared to observations. Such a contribution is therefore generally not regarded as a viable source for the acceleration of the expansion. In this letter we propose that the vacuum contribution actually provides a small positive value to the density energy of the universe. The underlying mechanism is a manifestation of the quantum nature of the gravitational field, through a Casimir-like effect from an additional compact dimension of space. A key ingredient is to assume that only modes with wavelength shorter than the Hubble length contribute to the vacuum. Such a contribution gives a positive energy density, has a Lorentz invariant equation of state in the usual 4D spacetime and hence can be interpreted as a cosmological constant. Its value agrees with observations for a radius of a 5th extra dimension given by $35\,\mu$m. This implies a modification of the gravitational inverse square law around this scale, close but below existing limits from experiments testing gravity at short range.
Assessing coastal vulnerability to climate change at regional scales is now mandatory in France since the adoption of recent laws to support adaptation to climate change. However, there is presently no commonly recognised method to assess accurately how sea level rise will modify coastal processes in the coming decades. Therefore, many assessments of the physical component of coastal vulnerability are presently based on a combined use of data (e.g. digital elevation models, historical shoreline and coastal geomorphology datasets), simple models and expert opinion. In this study, we assess the applicability and usefulness of a multi-criteria decision-mapping method (the analytical hierarchy process, AHP) to map physical coastal vulnerability to erosion and flooding in a structured way. We apply the method in two regions of France: the coastal zones of Languedoc-Roussillon (north-western Mediterranean, France) and the island of La Réunion (south-western Indian Ocean), notably using the regional geological maps. As expected, the results show not only the greater vulnerability of sand spits, estuaries and low-lying areas near to coastal lagoons in both regions, but also that of a thin strip of erodible cliffs exposed to waves in La Réunion. Despite gaps in knowledge and data, the method is found to provide a flexible and transportable framework to represent and aggregate existing knowledge and to support long-term coastal zone planning through the integration of such studies into existing adaptation schemes.
The water wave theory traditionally assumes the fluid to be perfect, thus neglecting all effects of the viscosity. However, the explanation of several experimental data sets requires the explicit inclusion of dissipative effects. In order to meet these practical problems, the theory of visco-potential flows has been developed (see P.-F. Liu & A. Orfila (2004) and D. Dutykh & F. Dias (2007)). Then, usually this formulation is further simplified by developing the potential in an entire series in the vertical coordinate and by introducing thus, the long wave approximation. In the present study we propose a derivation of dissipative Boussinesq equations which is based on asymptotic expansions of the Dirichlet-to-Neumann (D2N) operator. Both employed methods yield the same system by different ways.
We present a laboratory study on the instability of internal wave attractors in a trapezoidal fluid domain filled with uniformly stratified fluid. Energy is injected into the system via standing-wave-type motion of a vertical wall. Attractors are found to be destroyed by parametric subharmonic instability (PSI) via a triadic resonance which is shown to provide a very efficient energy pathway from long to short length scales. This study provides an explanation why attractors may be difficult or impossible to observe in natural systems subject to large amplitude forcing.
We introduce the paradigm of chaotic mathematical circuitry which shows some similarity to the paradigm of electronic circuitry especially in the frame of chaotic attractors for application purpose (cryptography, generic algorithms in optimization, control, ...).
The charisma of the leader is conveyed through multiple aspects: his ideas and vision and his perceivable verbal and non verbal behaviors. Among these perceivable behaviors there are the acoustic characteristics of speech. We present here a study on the perception of charisma in political speech. We collected speech statements with different illocutionary value taken from two speeches given by Umberto Bossi, the leader of an Italian party, before and after a stroke which caused him a voice disorder. Stimuli from the two condition differed significantly in the acoustic-prosodic features. In the first part of the study 40 French listeners rated normal speech stimuli (20 pre- and 20 post-stroke) and in the second part 22 French (11 pre- and 11 post-stroke) and 31 Italians (15 pre- and 16 post-stroke) rated the de-lexicalized version of the same stimuli. Results for the first part of the study show that pitch contour in Bossi's pre-stroke speech positively influence the perception of his speech as charismatic, as opposed to those some years after the stroke. Results for the de-lexicalized speech confirm for French listeners our hypothesis of the influence of the pitch contour in Bossi's charisma perception but they are controversial for Italian participants that seem to perceive Bossi as more charismatic in the post-stroke condition.
DBpedia knowledge base has been built from data extracted from Wikipedia. However, many existing relations among resources in DBpedia are missing links among articles from Wikipedia. In some cases, adding these links into Wikipedia will enrich Wikipedia content and therefore will enable bet- ter navigation. In previous work, we proposed PIA algorithm that predicts the best link to connect two articles in Wikipedia corresponding to those related by a semantic property in DB- pedia and respecting the Wikipedia convention. PIA calcu- lates this link as a path query. After introducing PIA results in Wikipedia, most of them were accepted by the Wikipedia community. However, some were rejected because PIA pre- dicts path queries that are too general. In this paper, we report the BlueFinder collaborative filtering algorithm that fixes PIA miscalculation. It is sensible to the specificity of the resource types. According to the conducted experimentation we found out that BlueFinder is a better solution than PIA because it solves more cases with a better recall.
This paper studies strategies for collision avoidance between two persons walking along crossing trajectories. It has been previously demonstrated that walkers are able to anticipate the risk of future collision and to react accordingly. The avoidance task has been described as a mutual control of the future distance of closest approach, MPD (i.e., Mininum Predicted Distance). In this paper, we studied the role of each walker in the task of controlling MPD. A specific question was: does the walker giving way (2nd at the crossing) and the one passing first set similar and coordinated strategies? To answer this question, we inspected the effect of motion adaptations on the future distance of closest approach. This analysis is relevant in the case of collision avoidance because subtle anticipatory behaviors or large last moment adaptations can finally yield the same result upon the final crossing distance. Results showed that collision avoidance is performed collaboratively and the crossing order impacts both the contribution and the strategies used: the participant giving way contributes more than the one passing first to avoid the collision. Both walkers reorient their path but the participant giving way also adapts his speed. Future work is planned to investigate the influence of crossing angle and TTC on adaptations as well as new types of interactions, such as intercepting or meeting tasks.
The Korba aquifer on the east coast of Cape Bon has been overexploited since the 1960s with a resultant reversal of the hydraulic gradient and a degradation of the quality due to seawater intrusion. In 2008, the authorities introduced integrated water resources planning based on a managed aquifer recharge with treated wastewater. Water quality monitoring was implemented in order to determine the different system components and trace the effectiveness of the artificial recharge. Groundwater samples taken from recharge control piezometers and surrounding farm wells were analyzed for their chemical contents, for their boron isotopes, a proven tracer of groundwater salinization and domestic sewage, and their carbamazepine content, an anti-epileptic known to pass through wastewater treatment and so recognized as a pertinent tracer of wastewater contamination. The system equilibrium was permanently disturbed by the different temporal dynamics of continuous processes such as cation exchange, and by threshold processes linked to oxidation-reductive conditions. The boron isotopic compositions significantly shifted back-and-forth due to mixing with end-members of various origins. Under the variable contribution of meteoric recharge, the Plio-Quaternary groundwater (δ11B of 35-40.6‰, a mean B concentration of 30 µmol/L, no carbamazepine, n=7) was subject to seawater intrusion that induced a high δ11B level (δ11B of 41.5-48.0‰, a mean B concentration of 36 µmol/L, and n=8). Fresh groundwater (δ11B of 19.89‰, B concentration of 2.8 µmol/L, no carbamazepine) was detected close to the recharge site and may represent the deep Miocene pole which feeds the upper Plio-Quaternary aquifer. The managed recharge water (δ11B of 10.67-13.8‰, n=3) was brackish and of poor quality with a carbamazepine content showing a large short term variability with an average daily levels of 328 ± 61 ng/L. A few piezometers in the vicinity of the recharge site gradually acquired a B isotopic composition close to the wastewater signature and showed an increasing carbamazepine content (from 20 to 910 ng/L). The combination of boron isotopic signatures with boron and carbamazepine contents is a useful tool to assess sources and mixing of treated wastewaters in groundwaters. Effluent quality needs to be greatly improved before injection to prevent further degradation of groundwater quality.
Créé en 1909, le jardin de Skrúður à Núpur (Dýrafjörður, Islande), lieu exceptionnel signalé par la XIVe édition du Premio Internazionale Carlo Scarpa per il Giardino décerné par la Fondazione Benetton Studi Ricerche (Trévise, Italie), invite à réfléchir sur l'histoire de la forêt en Islande, depuis l'époque de la colonisation jusqu'à aujourd'hui, et plus largement sur les enjeux actuels de la déforestation au niveau planétaire et les initiatives locales contre la désertification et en faveur du reboisement.
Créé en 1909, le jardin de Skrúður à Núpur (Dýrafjörður, Islande), lieu exceptionnel signalé par la XIVe édition du Premio Internazionale Carlo Scarpa per il Giardino décerné par la Fondazione Benetton Studi Ricerche (Trévise, Italie), invite à réfléchir sur l'histoire de la forêt en Islande, depuis l'époque de la colonisation jusqu'à aujourd'hui, et plus largement sur les enjeux actuels de la déforestation au niveau planétaire et les initiatives locales contre la désertification et en faveur du reboisement.
Cet article examine les pratiques patrimoniales développées autour de la Mahdiyya soudanaise (1881-1898) durant le Condominium anglo-égyptien (1899-1956). Tout en tenant compte de l'évolution sémantique des concepts de patrimoine et de turâth, il vise à montrer que cette période controversée de l'histoire soudanaise fut l'enjeu de processus de patrimonialisation, de dé-patrimonialisation et de contre-patrimonialisation déclenchés par des acteurs aux intérêts politiques et idéologiques très divergents : les néo-Mahdistes, qui avaient pour objectif l'accession du Soudan à une indépendance totale ; les Unionistes, qui préconisaient l'union politique du Soudan avec l'Egypte ; et les administrateurs britanniques, pour qui l'établissement d'un système colonial effectif impliquait l'anéantissement matériel et symbolique du régime mahdiste. L'analyse est notamment consacrée à la Mahdiyya en tant qu'objet oscillant entre patrimoine national et héritage familial, ceci à travers la figure de proue du mouvement néo-mahdiste, Sayyid 'Abd al-Rahman al-Mahdî (1885-1959). Outre diverses modalités de patrimonialisation sociales et intellectuelles mises en œuvre du côté néo-mahdiste, l'article met en évidence les efforts britanniques de dé-patrimonisalisation de la Mahdiyya ainsi que l'élaboration d'un contre-modèle patrimonial fondé sur la sacralisation mémorielle du général Charles George Gordon (1833-1885). Enfin, les tentatives des Unionistes visant à contrecarrer la patrimonialisation nationale de la Mahdiyya mettent en relief le fossé politique, idéologique et religieux séparant les deux principales tendances du nationalisme soudanais à l'époque du Condominium, qui trouvent leur expression dans les célèbres slogans "Le Soudan aux Soudanais" et "L'unité de la vallée du Nil".
In the history of the occidental and central dialects of Basque, the verbal periphrases composed by the verbal stem / or the participle and the auxiliaries *edin, *ezan, egin have undergone a change in the form of their principal verb. Until now, the bascologists have presented this modification as the generalization of the use of the participle within these three periphrases. Anyway, the 15th, 16th, 17th and 18th century texts' data seem to show different tendencies depending on the auxiliaries and the periods. The periphrasis based on the auxiliaries *edin and *ezan have generalized the use of the participle at different times, and the egin auxiliary based one seems to have always principally employed the participle as its lexical verb. Thus, these data give us good evidence for proposing that these three periphrases appeared and grammaticalized on the base of two different structures : (i) verbal stem + auxiliary (periphrases with the auxiliaries *edin and *ezan), (ii) participle + auxiliary (periphrasis with the auxiliary egin).
That article presents three texts of the same poem written by Pierre Topet-Etxahun. The first belongs to the assizes case file as a proof of the responsibility of the poet (1827) ; the second (1833) is taken on by Etxahun himself ; the third dated from 1842 shows how that poem turned out in the first step of the popular transmission we know. The different variants between the three texts make the trama of that study.
Dans le domaine de la modélisation des écoulements turbulents, les approche hybrides RANS/LES ont reçu récemment beaucoup d'attention car ils combinent le coût de calcul raisonnable du RANS et la précision de la LES.Parmi elles, le TPITM (Temporal Partially Integrated Transport Model) est une approche hybride RANS/LES temporelle qui surmonte les inconsistances du raccordement continu du RANS et de la LES grâce à un formalisme de filtrage temporel. Cependant, le modèle TPITM est relativement difficile à mettre en œuvre et, en particulier, nécessite l'utilisation d'une correction dynamique, contrairement à d'autres approches, notamment la DES (Detached Eddy Simulation).Cette thèse propose alors une approche hybride RANS/LES similaire à la DES, mais basée sur un filtrage temporel, déduite du modèle TPITM par équivalence, c'est-à-dire en imposant la même partition entre énergies résolue et modélisée. Ce modèle HTLES (Hybrid Temporal LES) combine les caractéristiques de la DES (facilité de mise en œuvre) et du TPITM (formalisme consistant, justification théorique des coefficients).Après calibration en turbulence homogène, l'approche est appliquée à des cas d'écoulements autour de cylindres carrés puis rectangulaires. La modélisation des tensions de sous-filtre est une adaptation au contexte hybride du modèle RANS k-wSST.
This paper presents the STAMP (system-theoretic accident modeling and processes) accident model, based on systems theory, and describes its application in the context of risk prevention related to the remediation of contaminated sediments. The implementation of the model is described, and results are presented both in methodological and technical terms. The goal of this article is to emphasize the need of new approaches to take into account hazards and accidents within socio-technical systems.
Ce travail de thèse apporte des éléments méthodologiques pour l'interprétation rapide de données électromagnétiques transitoires (TEM) aéroportées. Dans un premier temps, nous nous sommes intéressés au problème de l'inversion 1D qui est, à ce jour, un traitement standard. Nous nous sommes ensuite focalisés sur le problème de l'inversion 2D rapide. En nous basant sur les résultats de modélisations numériques, nous proposons un modèle empirique de sensibilité pour effectuer une inversion 2D rapide. Les tests effectués sur des données synthétiques et réelles s'avèrent très prometteurs. Ensuite, nous étudions analytiquement l'effet de la topographie. Pour un demi-espace homogène incliné, nous montrons que la direction des courants induits dans le sous-sol dépend de l'angle de l'interface air/sol. Nous proposons alors une méthode pour prendre en compte cet effet. Enfin, nous testons nos méthodes de traitement sur des données VTEM acquises dans le bassin de Franceville au Gabon.
Metastatic bone disease is a serious clinical complication for the treatment of patients with advanced cancer, but few therapeutic options are currently available. Bisphosphonates are an established standard care for these patients, but new treatments are now emerging, including the use of monoclonal antibodies targeting the RANK ligand. In this issue of the BJP, Reuter et al. provide evidence that thiocolchicoside, a semi-synthetic derivative of the naturally occurring colchicoside, extracted from the seeds of Gloriosa superba (Liliaceae), prevented osteoclactogenesis by suppressing RANK ligand-mediated NF-κB activation. Thiolcolchicoside may thus represent an attractive therapeutic option for the management of bone metastatic disease.
Context: Suicide is the second leading cause of death in adolescents and young adults in Europe. Reducing suicides is therefore a key public health target. Previous studies have shown associations between suicidal behaviors, depression and family factors. OBJECTIVE: To assess the role of family factors in depression and suicidality in a large community-based sample of adolescents and to explore specific contributions (e.g. mother vs. father; conflict vs. no conflict; separation vs. no separation) taking into account other risk factors. METHODS: A cross-sectional sample of adolescents aged 17 years was recruited in 2008. 36,757 French adolescents (18,593 girls and 18,164 boys) completed a questionnaire including socio-demographic characteristics, drug use, family variables, suicidal ideations and attempts. Current depression was assessed with the Adolescent Depression Rating Scale (ADRS). Adolescents were divided into 4 groups according to suicide risk severity (grade 1 = depressed without suicidal ideation and without suicide attempts, grade 2 = depressed with suicidal ideations and grade 3 = depressed with suicide attempts; grade 0 = control group). Multivariate regressions were applied to assess the Odds Ratio of potential risk factors comparing grade 1, 2 or 3 risk with grade 0. RESULTS: 7.5% of adolescents (10.4% among girls vs. 4.5% among boys) had ADRS scores compatible with depression; 16.2% reported suicidal ideations in the past 12 months and 8.2% reported lifetime suicide attempts. Repeating a year in school was significantly associated to severity grade of suicide risk (1 and 3), as well as all substance use, tobacco use (severity grades 2 and 3) and marijuana use (severity grade 3), for girls and boys. After adjustment, negative relationships with either or both parents, and parents living together but with a negative relationship were significantly associated with suicide risk and/or depression in both genders (all risk grades), and Odds Ratios increased according to risk severity grade. CONCLUSION: Family discord and negative relationship with parents were associated with an increased suicide risk in depressed adolescents. So it appears essential to take intrafamilial relationships into account in depressed adolescents to prevent suicidal behaviours.
The pilot phase of the ECRIN (European Clinical Research Infrastructure Network) certification programme for European data centres, in late 2011, led to a substantial revision of the original ECRIN standards, completed by June 2012. The pilot phase, the conclusions drawn from it and the revised set of standards are described. Issues concerning the further development of standards and related material are discussed, as are the methods available to best support that development. A strategy is outlined based on short-lived specific task groups, established as necessary by a steering group drawn from ECRIN-ERIC. A final section discusses possible future developments.
Several risk measures have been proposed in the literature. In this paper, we focus on the estimation of the Conditional Tail Expectation (CTE). Its asymptotic normality has been first established in the literature under the classical assumption that the second moment of the loss variable is finite, this condition being very restrictive in practical applications. Such a result has been extended by Necir {\it et al.} (2010) in the case of infinite second moment. In this framework, we propose a reduced-bias estimator of the CTE. We illustrate the efficiency of our approach on a small simulation study and a real data analysis.
We provide a first PAC-Bayesian analysis for domain adaptation (DA) which arises when the learning and test distributions differ. It relies on a novel distribution pseudodistance based on a disagreement averaging. Using this measure, we derive a PAC-Bayesian DA bound for the stochastic Gibbs classifier. This bound has the advantage of being directly optimizable for any hypothesis space. We specialize it to linear classifiers, and design a learning algorithm which shows interesting results on a synthetic problem and on a popular sentiment annotation task. This opens the door to tackling DA tasks by making use of all the PAC-Bayesian tools.
Let X₁,..,X_{n} denote an i.i.d. sample with light tail distribution and S₁ⁿ denote the sum of its terms; let a_{n} be a real sequence going to infinity with n. In a previous paper ([hal-00813262]) it is proved that as n→∞, given (S₁ⁿ/n>a_{n}) all terms X_{i_{ }} concentrate around a_{n} with probability going to 1. This paper explores the asymptotic distribution of X₁ under the conditioning events (S₁ⁿ/n=a_{n}) and (S₁ⁿ/n≥a_{n}) . It is proved that under some regulatity property, the asymptotic conditional distribution of X₁ given (S₁ⁿ/n=a_{n}) can be approximated in variation norm by the tilted distribution at point a_{n} , extending therefore the classical LDP case developed in Diaconis and Freedman (1988). Also under (S₁ⁿ/n≥a_{n}) the dominating point property holds. It also considers the case when the X_{i}'s are R^{d}-valued, f is a real valued function defined on R^{d} and the conditioning event writes (U₁ⁿ/n=a_{n}) or (U₁ⁿ/n≥a_{n}) with U₁ⁿ:=(f(X₁)+..+f(X_{n}))/n and f(X₁) has a light tail distribution. As a by-product some attention is paid to the estimation of high level sets of functions.
À l'attention du déposant
Le dépôt doit être effectué en accord avec les co-auteurs et dans le respect de la politique des éditeurs
La mise en ligne est assujettie à une modération, la direction de HAL se réservant le droit de refuser les articles ne correspondant pas aux critères de l'archive (voir le guide du déposant )
Tout dépôt est définitif, aucun retrait ne sera effectué après la mise en ligne de l'article
Consulter le ManuHAL Les fichiers textes au format pdf ou les fichiers images composant votre dépôt sont maintenant envoyés au CINES dans un contexte d'archivage à long terme.
À l'attention des lecteurs
Dans un contexte de diffusion électronique, tout auteur conserve ses droits intellectuels, notamment le fait de devoir être correctement cité et reconnu comme l'auteur d'un document.
Déposer
La convention de partenariat en faveur des archives ouvertes et de la plateforme mutualisée HAL a été signée le 2 avril 2013 :
en savoir plus
Déposer
Documents avec texte intégral
Répartition par domaines
Contact
Actualités
À voir
