Unravelling individual rhythmic abilities using machine learning

International audienceHumans can easily extract the rhythm of a complex sound, like music, and move to its regular beat, for example in dance. These abilities are modulated by musical training and vary significantly in untrained individuals. The causes of this variability are multidimensional and typically hard to grasp with single tasks. To date we lack a comprehensive model capturing the rhythmic fingerprints of both musicians and non-musicians. Here we harnessed machine learning to extract a parsimonious model of rhythmic abilities, based on the behavioral testing (with perceptual and motor tasks) of individuals with and without formal musical training ( n = 79). We demonstrate that the variability of rhythmic abilities, and their link with formal and informal music experience, can be successfully captured by profiles including a minimal set of behavioral measures. These profiles can shed light on individual variability in healthy and clinical populations, and provide guidelines for personalizing rhythm-based interventions

Semi-stability and local wall-crossing for hermitian Yang-Mills connections

We consider a sufficiently smooth semi-stable holomorphic vector bundle over a compact Kähler manifold. Assuming the automorphism group of its graded object to be abelian, we provide a semialgebraic decomposition of a neighbourhood of the polarisation in the Kähler cone into chambers characterising (in)stability. For a path in a stable chamber converging to the initial polarisation, we show that the associated HYM connections converge to an HYM connection on the graded object

Être orphelin et élève dans la littérature jeunesse. La littérature jeunesse comme médiation d’une parole sur l’orphelinage entre les familles endeuillées et l’institution scolaire

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Permutations based model for business performance

International audienceThis article is devoted to the development of a machine learning statistical framework to drive company's objectives. To this end, their sales data are used to target efficiently the issues or opportunities by a ranking. We implement a permutation based model using generalized Mallows models dealing with quantitative values, considering that a ranking is a permutation. The advantage of the generalized version is the possibility to differentiate the cost to move each element in the permutation. In our model, we differentiate the cost of an inversion in the permutation by using the gap value between the two elements. We propose model parameters estimators and we illustrate our estimation procedure on simulated data and on a real application

De la matière historique à l’outil numérique : comment s’articule le travail des experts, historiens et informaticiens, avec les agences de développement ?

International audienceWe consider the methods of joint work of experts from historical and computer-related disciplines during the implementation of digital mediation devices in heritage structures (monuments, museums). Experts in history and computer science meet within the framework of projects led by development agencies to whom cultural structures entrust the elaboration of digital mediation devices. The working methods of each are very different, but must nevertheless be adjusted in order to produce a technological container and its scientific content. During these exchanges, adjustments and negotiations, the researchers seem to be solicited only for the production of raw data and concrete technical solutions, which evacuates the fundamental scientific questions. It seems to us that several elements have an impact on the arbitrations that take place: the institutional context of the creation of the system as well as the initial training and acquired experience of the different people involved in these projects.Nous abordons les méthodes de travail en commun d’experts issus de disciplines historiques et liées à l’informatique lors de la mise en place de dispositifs de médiation numériques dans des structures patrimoniales (monuments, musées). Des experts en histoire et en informatique se rencontrent dans le cadre de projets pilotés par des agences de développement à qui des structures culturelles confient l’élaboration de dispositifs de médiation numériques. Les méthodes de travail des uns et des autres sont très différentes mais doivent néanmoins s’ajuster afin de produire un contenant technologique et son contenu de nature scientifique. Lors de ces échanges, faits d’ajustements et de négociations, les chercheurs ne semblent sollicités que pour la production de données brutes et de solutions techniques concrètes, ce qui évacue les questions scientifiques de fond. Il nous semble que plusieurs éléments impactent les arbitrages qui ont alors lieu : le contexte institutionnel de la création du dispositif ainsi que la formation initiale et les expériences acquises des différentes personnes impliquées dans ces projets

Systematic Review on Learning-based Spectral CT

International audienceSpectral computed tomography (CT) has recently emerged as an advanced version of medical CT and significantly improves conventional (single-energy) CT. Spectral CT has two main forms: dual-energy computed tomography (DECT) and photon-counting computed tomography (PCCT), which offer image improvement, material decomposition, and feature quantification relative to conventional CT. However, the inherent challenges of spectral CT, evidenced by data and image artifacts, remain a bottleneck for clinical applications. To address these problems, machine learning techniques have been widely applied to spectral CT. In this review, we present the state-of-the-art data-driven techniques for spectral CT

Scattering rigidity for analytic metrics

International audienceFor analytic negatively curved Riemannian manifold with analytic strictly convex boundary, we show that the scattering map for the geodesic flow determines the manifold up to isometry. In particular one recovers both the topology and the metric. More generally, our result holds in the analytic category under the no conjugate point and hyperbolic trapped sets assumptions