Valeur de marché et mesures comptables: les entreprises de la nouvelle économie française

Cet article s’intéresse à l’évaluation des entreprises de la nouvelle économie française. Il examine le lien entre leur valeur de marché et les principaux paramètres de mesure de la situation financière décrits dans les états financiers : le résultat, les flux de trésorerie et les capitaux propres. Les exercices 2000-2002 servent de cadre temporel à l’analyse. Cette recherche s’inscrit dans la lignée des études visant à montrer la pertinence des mesures comptables et l’utilité de l’information financière pour expliquer les valorisations boursières des sociétés. La méthodologie utilisée est celle des études d’association. Les résultats testés à l’aide de trois modèles montrent l’intérêt du résultat de l’exercice et du résultat opérationnel dans l’explication des valeurs de marché des entreprises.This paper provides further evidence on the financial valuation of French start-ups over the period 2000-2002. Using association studies, relevant indicators such as net income versus cash flows are used to explain market value and as proxies of growth opportunities. Results show the relevance of accounting models and figures, particularly the ability of net income and operating income to convey useful information for financial analysts in different business settings. These findings from three models show the importance of fundamental analysis when data are available

Comparaison de trois méthodologies ESG : les bases de données extra-financières fournissent-elles la même information ?

L’objet de la recherche est d’étudier la convergence des notes ESG de trois organismes de notation extra-financière. Dans un contexte de tétranormalisation (Savall et Zardet, 2005), la validité et la conformité des ratings ESG, compte tenu des missions confiées aux agences, sont peu étudiées (Chatterji et al., 2016). L’étude porte sur un échantillon de 247 sociétés cotées européennes et 65 anglo-saxonnes lors des années 2009-2012. Elle évalue les différences d’approche des trois organismes. La méthodologie utilisée est l’analyse en composantes principales qui établit les corrélations entre les scores puis la régression longitudinale qui identifie les facteurs de différenciation observés.The aim of the research is to study the convergence of the ESG ratings of three non-financial rating organizations. In the context of tetrastandardization (Savall and Zardet, 2005), the validity and conformity of ESG ratings, given the missions entrusted to the agencies, are poorly studied (Chatterji et al., 2016). The study is based on a sample of 247 listed European companies and 65 Anglo-Saxons in the years 2009-2012. It assesses the differences in approach of the three organizations. The methodology used is the principal component analysis which establishes the correlations between the scores and then the longitudinal regression which identifies the differentiation factors observed

Piecewise Affine Registration of Biological Images for Volume Reconstruction

This manuscript tackles the reconstruction of 3D volumes via mono-modal registration of series of 2D biological images (histological sections, autoradiographs, cryosections, etc.). The process of acquiring these images typically induces composite transformations that we model as a number of rigid or affine local transformations embedded in an elastic one. We propose a registration approach closely derived from this model. Given a pair of input images, we first compute a dense similarity field between them with a block matching algorithm. We use as a similarity measure an extension of the classical correlation coefficient that improves the consistency of the field. A hierarchical clustering algorithm then automatically partitions the field into a number of classes from which we extract independent pairs of sub-images. Our clustering algorithm relies on the Earth mover’s distribution metric and is additionally guided by robust least-square estimation of the transformations associated with each cluster. Finally, the pairs of sub-images are, independently, affinely registered and a hybrid affine/non-linear interpolation scheme is used to compose the output registered image. We investigate the behavior of our approach on several batches of histological data and discuss its sensitivity to parameters and noise

Capital intellectuel, gouvernance et facteurs institutionnels

Cet article montre le rôle joué par la gouvernance dans l’évaluation et à la mesure du capital intellectuel et de ses composantes par les analystes d’un fonds d’investissement spécialisé dans l’investissement socialement responsable ainsi que l’influence du milieu socio-économique et institutionnel dans lequel les entreprises s’insèrent. Les données examinées concernent les années 2010 à 2012 pour un échantillon de 289 sociétés cotées européennes pour la plupart de capitalisation moyenne extrait d’une population mère de plus de mille entreprises suivie par ce fonds privé

Fusion of autoradiographies with an MR volume using 2-D and 3-D linear transformations

In the past years, the development of 3-D medical imaging devices has given access to the 3-D imaging of in vivo tissues, from an anatomical (MR, CT) or even functional point of view (fMRI, PET, SPECT). However, despite huge technological progress, the resolution of these images is still not sufficient to image to anatomical or functional details, that can only be revealed by in vitro imaging (e.g. histology, autoradiography), eventually enhanced by staining. The deep motivation of this work is the comparison of activations detected by fMRI series analysis to the ones that can be observed in autoradiographic images. The aim of the presented work is to fuse the autoradiographic data with the pre-mortem anatomical MR image, to facilitate the above mentioned comparison. First, we reconstruct a 3-D volume, coherent both in geometry and intensity, from the 2-D autoradiographic sections. Second, this volume is fused with the MR image, that allows to geometrically correct the reconstruction to make it comparable to the MR image. We show that this fusion can be achieved by using only simple global transformations (rigid and/or affine, 2-D and 3-D), yielding a very satisfactory result

Intra-operative Registration for Stereotactic Procedures driven by a combined Biomechanical Brain and CSF Model

International audienceDuring stereotactic neurosurgery, the brain shift could affect the accuracy of the procedure. However, this deformation of the brain is not often considered in the pre-operative planning step or intra-operatively, and may lead to surgical complications, side effects or ineffectiveness. In this paper, we present a method to update the pre-operative planning based on a physical simulation of the brain shift. Because the simulation requires unknown input parameters, the method relies on a parameter estimation process to compute the intracranial state that matches the partial data taken from intra-operative modalities. The simulation is based on a biomechanical model of the brain and the cerebro-spinal fluid. In this paper, we show on an anatomical atlas that the method is numerically sound

Competitive segmentation of the hippocampus and the amygdala from MRI scans

The hippocampus and the amygdala are two brain structures which play a central role in several fundamental cognitive processes. Their segmentation from Magnetic Resonance Imaging (MRI) scans is a unique way to measure their atrophy in some neurological diseases, but it is made difficult by their complex geometry. Their simultaneous segmentation is considered here through a competitive homotopic region growing method. It is driven by relational anatomical knowledge, which enables to consider the segmentation of atrophic structures in a straightforward way. For both structures, this fast algorithm gives results which are comparable to manual segmentation with a better reproducibility. Its performances regarding segmentation quality, automation and computation time, are amongst the best published data.L’hippocampe et l’amygdale sont deux structures cérébrales intervenant dans plusieurs fonctions cognitives fondamentales. Leur segmentation, à partir de volumes d’imagerie par résonance magnétique (IRM), est un outil essentiel pour mesurer leur atteinte dans certaines pathologies neurologiques, mais elle est rendue difficile par leur géométrie complexe. Nous considérons leur segmentation simultanée par une méthode de déformation homotopique compétitive de régions. Celle-ci est guidée par des connaissances anatomiques relationnelles ; ceci permet de considérer directement des structures atrophiées. Rapide, l’algorithme donne, pour les deux structures, des résultats comparables à la segmentation manuelle avec une meilleure reproductibilité. Ses performances, concernant la qualité de la segmentation, le degré d’automatisation et le temps de calcul, sont parmi les meilleures de la littérature

Do the ESG scores help to select the most successful companies?

Financial performance, the main purpose for the investors, is easily measured by financial reporting. On the other hand, its numerous causes, for example the combination of the knowledge and the acts of the employees of the company, remain anonymous and are not reported. This article uses the ESG scores measured by financial analysts and portfolio managers of a French SRI fund to assess the respective influences of environmental, social, governance activities in order to select the most successful companies. For that, these scores are combined with a set of financial indicators of 143 European listed companies, collected from the database of the SRI Fund. The Companies are followed over a period of 5 years. Governance scores are significant but not those related to the environment and social activities. In order to explain the discriminant power of governance, its scores are broken down into sub-scores. The tests are significant for financial communication: the reliability of published information, the transparency, quality and stability of the management team as well as for organizational characteristics such as the separation of tasks and the quality of internal control. The results confirm the classification of companies in the two chosen categories which differ in their level of financial performance. The results suggest that governance activities are highly valued by financial analysts. This should encourage business leaders and their teams to put in place an effective governance policy. The argument is equally strong for practitioners, especially portfolio managers, who should not underestimate governance issues in their search of the most successful companies

Intra-operative Registration for Deep Brain Stimulation Procedures based on a Full Physics Head Model

International audienceBrain deformation is a factor of inaccuracy during stereotactic neurosurgeries. If this phenomenon is not considered in the pre-operative planning or intra-operatively, it could lead to surgical complications, side effects or ineffectiveness. In this paper, we present a patient-specific method to update the pre-operative planning based on a physical simulation of the brain shift. A minimization process estimates parameters of the simulation in order to compute the brain tissue deformation matching the partial data taken from intra-operative modalities. The simulation is based on a patient-specific biomechanical model of the brain and the cerebro-spinal fluid. We validate the method on a patient with a post-operative MRI

Surface reconstruction using active contour models

Variational methods have been frequently used for surface reconstruction and contour extraction (snakes). We present a surface reconstruction method where we assume the surface composed of two regions of different types of smoothness. One region of the surface models a "lake" (constant height region with uphill borders). It is surrounded by the other background region which is reconstructed using classic surface regularization. The boundary between the two regions, represented by a closed curve is determined with the help of an active contour model. Then the surface is reconstructed by minimizing the energy terms in each region. Minimizing a global energy defined on the couple of unknowns - boundary curve and surface - permits to introduce other forces on the curve. The surface reconstruction and contour extraction tasks are then made together. We have applied this model for segmenting a synthetic Digital Terrain Model (DTM) image which represents a noisy mountain and lake