The segment information practices of the biggest European companies

25 pagesThe sample includes 50 companies from the FT Europe 500, the 35 biggest firms and 15 firms ranked between 36th and 100th which were randomly chosen. Insurance companies and banks were excluded. Several sources were used: consolidated financial statements certified by auditors, management reports, slides used during presentations of results and press releases when available. The report analyses the choices made by management concerning indicators disclosed according to IFRS 8 and segment identification. It also compares the redundancy of disclosure across different media: press releases, slides used during presentations of results and management reports. Our objective is to explore the relevance and comparability of segment information.Effectuée à partir d'un échantillon de 50 entreprises européennes, cette étude analyse les pratiques des entreprises en matière d'information sectorielle en utilisant de multiples sources : comptes consolidés, rapports annuels, communiqués de presse. Les résultats montrent que les pratiques sont très diversifiés et mettent en évidence les limites de la pertinence et de la comparabilité de l'information sectorielle telle que publiée en IFRS 8

Estimer la datation, la durée et les discontinuités de l'occupation des sites archéologiques à l'aide de la modélisation des faciès céramiques

http://www.univ-tours.fr/lat/pdf/F2_13.pdfpremière étape d'une démarche statistique dont l'objectif est des préciser la datation des contextes archéologiques. Pour plus de précision : voir aussi les articles plus récents des mêmes auteurs publiés en 2006 et 2008.Le but de cet article est de présenter une démarche méthodologique fondée sur la stratigraphie et le mobilier archéologique - tout particulièrement la céramique - qui a pour objet de formaliser, étape par étape, la construction d'une Chronologie Absolue, ici à l'échelle de la ville. Il s'agit d'étudier les contextes archéologiques de plusieurs fouilles afin d'établir une échelle de temps qui tiennent aussi bien compte des temporalités attestées que des hiatus chronologiques dans un espace choisi. Cette tentative, très fructueuse en interrogations nouvelles, nous a fait prendre conscience de certaines lacunes terminologiques existantes en archéologie dans le domaine des échelles de temps. Une terminologie adaptée conduisant à une meilleure mise en lumière de la notion de temps en archéologie a alors été élaborée : Chronologie Relative Intégrante, Temporalité, Hiatus Chronologique, Site, Lieu, Espace céramiques...dont les définitions se trouvent dans un glossaire en annexe. L'originalité de cette étude est également l'utilisation de la modélisation statistique permettant d'obtenir des réponses archéologiques dans le cas de données qualitatives et quantitatives nombreuses. Cette approche, qui complète la démarche archéologique générale utilisée à Chinon et à Rigny, a été mise en œuvre à Tours et correspond à la dernière partie de cet article

Le rôle de l'assurance dans la gestion des risques psychosociaux en entreprise

National audienceLes risques psychosociaux sont de plus en plus d'actualité dans nos sociétés industrialisées et leurs conséquences ont des effets non négligeables sur la performance des entreprises. La loi et les institutions prennent déjà en compte ce fait de société. Cependant, dans ce contexte, une question se pose : dans quelle mesure l'assurance peut-elle devenir une solution intelligente et acceptable face à ces risques ? L'absence d'une définition juridique précise les rend difficilement assurables. Néanmoins, les assurances ont un rôle à jouer, non pas en financement, mais en accompagnement, comme le font des grands cabinets de courtage dans le cadre de leur devoir de conseil

Model-based measurement of epileptic tissue excitability.

International audienceIn the context of pre-surgical evaluation of epileptic patients, depth-EEG signals constitute a valuable source of information to characterize the spatiotemporal organization of paroxysmal interictal and ictal activities, prior to surgery. However, interpretation of these very complex data remains a formidable task. Indeed, interpretation is currently mostly qualitative and efforts are still to be produced in order to quantitatively assess pathophysiological information conveyed by signals. The proposed EEG model-based approach is a contribution to this effort. It introduces both a physiological parameter set which represents excitation and inhibition levels in recorded neuronal tissue and a methodology to estimate this set of parameters. It includes Sequential Monte Carlo nonlinear filtering to estimate hidden state trajectory from EEG and Particle Swarm Optimization to maximize a likelihood function deduced from Monte Carlo computations. Simulation results illustrate what it can be expected from this methodology

Various Ways to Compute the Continuous-Discrete Extended Kalman Filter

International audienceThe Extended Kalman Filter (EKF) is a very popular tool dealing with state estimation. Its continuous-discrete version (CD-EKF) estimates the state trajectory of continuous-time nonlinear models, whose internal state is described by a stochastic differential equation and which is observed through a noisy nonlinear form of the sampled state. The prediction step of the CD-EKF leads to solve a differential equation that cannot be generally solved in a closed form. This technical note presents an overview of the numerical methods, including recent works, usually implemented to approximate this filter. Comparisons of theses methods on two different nonlinear models are finally presented. The first one is the Van der Pol oscillator which is widely used as a benchmark. The second one is a neuronal population model. This more original model is used to simulate EEG activity of the cortex. Experiments showed better stability properties of implementations for which the positivity of the prediction matrix is guaranteed

Detection of Phase Jumps of Free Core Nutation of the Earth and their Concurrence with Geomagnetic Jerks

We detected phase jumps of the Free Core Nutation (FCN) of the Earth directly from the analysis of the Very Long Baseline Interferometer (VLBI) observation of the Earth rotation for the period 1984-2003 by applying the Weighted Wavelet Z-Transform (WWZ) method and the Short-time Periodogram with the Gabor function (SPG) method. During the period, the FCN had two significant phase jumps in 1992 and 1998. These epochs coincide with the reported occurrence of geomagnetic jerks.Comment: 8 pages, 4 figure

Willingness to pay for informal care in France: the value of funding support interventions for caregivers

Objectives: This article aims to assess the relationship between the monetary value of informal care - approximated with the caregiver's willingness to pay to reduce caregiving time - and the caregiver's need of three types of support services: care training, respite care and support group. Developing such services may be the only way to provide sustainable informal care in the future, along with efficient allocation. Data & Methods: Data used stemmed from two representative national surveys conducted by French National Institute of Statistics and Economic Studies and the French Head Office of Research, Studies, Evaluation and Statistics of the Social Affairs Ministry in 2008. The contingent valuation method was used to approximate the monetary value of informal care. The model was run on 223 informal caregivers of people with Alzheimer's Disease. Statistical analyses were performed using Heckman's two-step estimation strategy, which is known to correct selection bias. Results: On average, one hour of informal care was estimated at €12.1. Monetary value of informal care was influenced by the caregiver's need of care training (p<0.01). No similar association was found for respite care or support group. Discussion: Since informal caring value increases with caregivers' need of care training, improving caring skills and capabilities through training support is likely to improve its benefits