Extraction of Pertinent Subsets from Time-Frequency Representations for Detection and Recognition Purposes

International audienceA time-frequency representation can highlight non-stationarities in a signal. We propose to extract subsets from the Time-Frequency Representation (TFR) for classification or recognition purposes. We developed two approaches. The first one is developed for TFRs obtained from the Short Time Fourier Transform or the gliding Minimum Variance method. The extraction of compact subsets is viewed as a segmentation of the TFR, which is performed by morphological filtering and Watershed segmentation. The second approach is developed when the TFR has been obtained using parametric estimators. We consider a hybrid estimator, the ARCAP method, and use a Kalman filter trajectory tracker to extract spectral lines. The proposed methods are illustrated by examples on natural signals : dolphin whistle acoustical signals, cavitation signals and seismic signals produced by snow avalanches

L’économie sociale au Québec à travers les crises structurelles et les grandes transformations (1850-2008)

Nous proposons, ici, une périodisation du développement de l’économie sociale québécoise en relation avec les « grandes crises » économiques et politiques depuis les années 1850. Nous avons ainsi identifié cinq grandes configurations de l’économie sociale québécoise, qui regroupent les diverses composantes de cette dernière à chaque époque (coopératives, mutuelles, fonds de travailleurs, associations ayant des activités économiques, etc.). Cette analyse des configurations montre comment les initiatives d’économie sociale répondent aux urgences provoquées par les « destructions créatrices » apportées par les crises et mettent en avant des « innovations créatrices » selon les aspirations pour un monde meilleur. À la lumière de cette analyse sociohistorique, nous croyons qu’une nouvelle vague d’innovations au sein de l’économie sociale émergera de la crise économique récente. Une appréciation réaliste des expériences passées nous invite toutefois à la prudence quant à leur portée.This paper is a classification – by historical period – of the development of Québec’s social economy as it relates to major economic and political crises since the 1850s. It identifies the five major configurations of Québec’s social economy, which comprise the various components of social economy (cooperatives, mutual companies, worker funds, associations engaging in economic activities, etc.) in each period. Through this analysis of configurations, we demonstrate how social economy initiatives have responded to the urgent situations associated with the « creative destruction » brought on by the crises and highlighted the « creative innovation » that corresponds to hopes for a better world. A new wave of innovation within the social economy should emerge from the recent economic crisis. However, a realistic assessment of past experience suggests that we exercise caution in defining its impact.El artículo propone una periodización sobre el desarrollo de la economía social quebecense en el marco de las grandes « crisis » económicas y políticas desde la década de 1850. Se identifican cinco configuraciones principales de economía social quebecense que incluyen para cada época a sus diversos componentes (cooperativas, mutualidades, fondos de trabajadores, asociaciones que desarrollan actividades económicas, etc.). El análisis sobre las configuraciones permite mostrar cómo las iniciativas de economía social responden a la vez a las urgencias causadas por las « destrucciones creativas » que producen las crisis, y generan « innovaciones creativas » de conformidad con las aspiraciones por un mundo mejor. Una nueva ola de innovaciones en la economía social puede emerger de la crisis económica. Una evaluación realista de las experiencias pasadas, invita a la prudencia en cuanto a su significado

Multilingual Unsupervised Sentence Simplification

Progress in Sentence Simplification has been hindered by the lack of supervised data, particularly in languages other than English. Previous work has aligned sentences from original and simplified corpora such as English Wikipedia and Simple English Wikipedia, but this limits corpus size, domain, and language. In this work, we propose using unsupervised mining techniques to automatically create training corpora for simplification in multiple languages from raw Common Crawl web data. When coupled with a controllable generation mechanism that can flexibly adjust attributes such as length and lexical complexity, these mined paraphrase corpora can be used to train simplification systems in any language. We further incorporate multilingual unsupervised pretraining methods to create even stronger models and show that by training on mined data rather than supervised corpora, we outperform the previous best results. We evaluate our approach on English, French, and Spanish simplification benchmarks and reach state-of-the-art performance with a totally unsupervised approach. We will release our models and code to mine the data in any language included in Common Crawl

European Clearinghouse: Report on External Hazard related events at NPPs

External phenomena are a significant source of hazards to nuclear power plant operation, and thus it is important to investigate the existing operational experience in this kind of events. The objective is to determine the adequacy of protection of nuclear power plants against external hazards and the effectiveness of corrective actions, as well as to provide recommendations on how to prevent or mitigate the impact of external phenomena on NPP operation. IAEA Safety Guide NS-G-1.5 defines external events as "events that originate either off the site or within the boundaries of the site but from sources that are not directly involved in the operational states of the nuclear power plant units, such as fuel depots or areas for the storage of hazardous materials handled during the construction, operation and decommissioning of units located at the same site". This Summary Report presents the results of a comprehensive study performed by the European Clearinghouse on Operating Experience Feedback of NPP with the support of IRSN and GRS. It addresses both natural origin and man-induced external events, with the exception of the earthquake hazard.JRC.F.5-Nuclear Reactor Safety Assessmen