Développements d'Edgeworth de deux estimateurs d'une proportion de mesures

29 pages.Dans ce preprint, nous établissons des développements d'Edgeworth de deux estimateurs d'une proportion de mesures $\pi$. Le premier est construit à partir de la méthode du maximum de vraisemblance et le second à l'aide des estimateurs sans biais et de variance minimale. Ces résultats sont motivés par leurs applications dans les laboratoires de contrôle ou dans l'industrie chimique, pharmaceutique, agroalimentaire, etc

Using multitable techniques for assessing Phytoplankton Structure and Succession in the Reservoir Marne (Seine Catchment Area, France)

4 pagesInternational audienceMicro-organisms, especially phytoplankton species, may be considered as potential indicators of local and more global changes in aquatic ecosystems and may thus constitute an excellent biomarker of water quality. Multitable analyses, such as partial triadic analysis and multiple coinertia analysis, are a well suited statistical tool to get a clear representation of the spatial and temporal organization of the assemblages of these different species and hence assess for the existence of changes in water quality. Handling of the few missing data was done using the NIPALS algorithm

Estimation of reference curves for fetal weight

International audienceOBJECTIVES Reference or standard curves are required in many biomedical problems. Values which lie outside the limits of these reference curves may indicated the presence of disorder. Data are from the French EDEN mother-child cohort [1]. We are studying fetal weight (in grammes) that depends on the gestional age (GA) in the second and the third trimesters of mother's pregnancy. Some classical parametric and semi-parametric methods as polynomial [2][3] and LMS method [4][5] or nonparametric methods as kernel estimation [6] are used to construct these curves. However, some of them requires strong assumptions

Dynamic allocation optimization in A/B tests using classification-based preprocessing

An A/B test evaluates the impact of a new technology by running it in a real production environment and testing its performance on a set of items. Recently, promising new methods are optimizing A/B tests with dynamic allocation. They allow for a quicker result regarding which variation (A or B) is the best, saving money for the user. However, dynamic allocation by traditional methods requires certain assumptions, which are not always verified in reality. This is mainly due to the fact that the populations tested are not homogeneous. This document reports on the new reinforcement learning methodology which has been deployed by the commercial A/B testing platform AB Tasty. We provide a new method that not only builds homogeneous groups for a user, but also allows to find the best variation for these groups in a short period of time. This paper provides numerical results on AB Tasty data, but also on public data sets, to demonstrate an improvement in A/B testing over traditional methods

How visual attention span and phonological skills contribute to N170 print tuning: An EEG study in French dyslexic students

Developmental dyslexia is a disorder characterized by a sustainable learning deficit in reading. Based on ERP-driven approaches focusing on the visual word form area, electrophysiological studies have pointed a lack of visual expertise for written word recognition in dyslexic readers by contrasting the left-lateralized N170 amplitudes elicited by alphabetic versus non-alphabetic stimuli. Here, we investigated in 22 dyslexic participants and 22 age-matched control subjects how two behavioural abilities potentially affected in dyslexic readers (phonological and visual attention skills) contributed to the N170 expertise during a word detection task. Consistent with literature, dyslexic participants exhibited poorer performance in these both abilities as compared to healthy subjects. At the brain level, we observed (1) an unexpected preservation of the N170 expertise in the dyslexic group suggesting a possible compensatory mechanism and (2) a modulation of this expertise only by phonological skills, providing evidence for the phonological mapping deficit hypothesis