The dynamo bifurcation in rotating spherical shells

We investigate the nature of the dynamo bifurcation in a configuration applicable to the Earth's liquid outer core, i.e. in a rotating spherical shell with thermally driven motions. We show that the nature of the bifurcation, which can be either supercritical or subcritical or even take the form of isola (or detached lobes) strongly depends on the parameters. This dependence is described in a range of parameters numerically accessible (which unfortunately remains remote from geophysical application), and we show how the magnetic Prandtl number and the Ekman number control these transitions.Comment: 16 pages, 14 figure

Influence des points d'ancrage pour l'extraction lexicale bilingue à partir de corpus comparables spécialisés

International audienceBilingual lexicon extraction from comparable corpora gives good results for large corpora but drops significantly for small size corpora. In order to compensate this weakness, we suggest a new contribution dedicated to the lexical alignment from specialized comparable corpora that strengthens the representativeness of the lexical contexts based on domainspecific vocabulary. The experiments carried out in this way show that taking better account the specialized vocabulary induces a significant improvement in the quality of extracted lexicons

Apport d'un corpus comparable déséquilibré à l'extraction de lexiques bilingues

National audienceThe main work in bilingual lexicon extraction from comparable corpora is based on the implicit hypothesis that corpora are balanced. However, the different related approaches are relatively insensitive to sizes of each part of the comparable corpus. Within this context, we study the influence of unbalanced comparable corpora on the quality of bilingual terminology extraction through different experiments. Our results show the conditions under which the use of an unbalanced comparable corpus can induce a significant gain in the quality of extracted lexicons

Apport des termes complexes à l'acquisition lexicale multilingue à partir de corpus comparables spécialisés : entre intuition et réalité

National audienceEn acquisition lexicale multilingue à partir de corpus comparables, les méthodes traditionnelles pour identifier un terme et sa traduction s'appuient sur des contextes lexicaux composés de mots ou termes simples. Or en domaine spécialisé, les termes complexes sont tout autant précis, moins ambigus et reflètent mieux la spécificité du domaine que les termes simples. Leur prise en compte dans les contextes lexicaux devrait donc permettre d'améliorer la précision des méthodes d'alignement. Cette intuition ne s'avérant pas correcte, nous présentons dans cet article une série d'expériences visant à en préciser les causes

Identification of Fertile Translations in Medical Comparable Corpora: a Morpho-Compositional Approach

This paper defines a method for lexicon in the biomedical domain from comparable corpora. The method is based on compositional translation and exploits morpheme-level translation equivalences. It can generate translations for a large variety of morphologically constructed words and can also generate 'fertile' translations. We show that fertile translations increase the overall quality of the extracted lexicon for English to French translation

Language Models for Handwritten Short Message Services

International audienceHandwriting is an alternative method for entering texts composing Short Message Services. However, a whole new language features the texts which are produced. They include for instance abbreviations and other consonantal writing which sprung up for time saving and fashion. We have collected and processed a significant number of such handwriting SMS, and used various strategies to tackle this challenging area of handwriting recognition. We proposed to study more specifically three different phenomena: consonant skeleton, rebus, and phonetic writing. For each of them, we compare the rough results produced by a standard recognition system with those obtained when using a specific language model

Looking for Transliterations in a Trilingual English, French and Japanese Specialised Comparable Corpus

International audienceTransliterations and cognates have been shown to be useful in the case of bilingual extraction from parallel corpora. Observation of transliterations in a trilingual English, French and Japanese specialised comparable corpus reveals evidences that they are likely to be used with comparable corpora too, since they are an important and relevant part of the common vocabulary, but they also yield links between Japanese and English/French corpora