Administration et gestion des contrats XL

Les grands contrats de travaux génèrent un grand nombre de commandes (OSVC) passées par un grand nombre de responsables techniques. Ils sont généralement basés sur des bordereaux de prix associés à un éventail de conditions économiques adaptées aux besoins complexes et variés des multiples utilisateurs du CERN nécessitant des calculs sophistiqués. L'administration des commandes, le suivi des travaux et de la facturation doivent répondre aux besoins de tous les acteurs. Les responsables techniques doivent jouir de la plus large indépendance administrative dans le respect des règlements CERN et des conditions contractuelles. Le contrôle des métrés et décomptes doit être rigoureux et d'une traçabilité complète. L'utilisation des bases de données Oracle a déjà permis l'intégration des données administratives et techniques. Le Web nous invite à une communication totale et transparente entre les utilisateurs, les services techniques et les contractants. De nouveaux types de contrat sont à inventer dans la perspective des futures applications, ils devraient être encore plus faciles à utiliser et plus intégrés avec les outils techniques

Burgers' equation in 2D SU(N) YM

It is shown that the logarithmic derivative of the characteristic polynomial of a Wilson loop in two dimensional pure Yang Mills theory with gauge group SU(N) exactly satisfies Burgers' equation, with viscosity given by 1/(2N). The Wilson loop does not intersect itself and Euclidean space-time is assumed flat and infinite. This result provides a precise framework in 2D YM for recent observations of Blaizot and Nowak and was inspired by their work.Comment: Final version -- accepted for publication in PLB - fixed abstract listin

Exactly Integrable Dynamics of Interface between Ideal Fluid and Light Viscous Fluid

It is shown that dynamics of the interface between ideal fluid and light viscous fluid is exactly integrable in the approximation of small surface slopes for two-dimensional flow. Stokes flow of viscous fluid provides a relation between normal velocity and pressure at interface. Surface elevation and velocity potential of ideal fluid are determined from two complex Burgers equations corresponding to analytical continuation of velocity potential at the interface into upper and lower complex half planes, respectively. The interface loses its smoothness if complex singularities (poles) reach the interface.Comment: 5 pages, 2 figures; submitted to Physics Letter

High frame-rate cardiac ultrasound imaging with deep learning

Cardiac ultrasound imaging requires a high frame rate in order to capture rapid motion. This can be achieved by multi-line acquisition (MLA), where several narrow-focused received lines are obtained from each wide-focused transmitted line. This shortens the acquisition time at the expense of introducing block artifacts. In this paper, we propose a data-driven learning-based approach to improve the MLA image quality. We train an end-to-end convolutional neural network on pairs of real ultrasound cardiac data, acquired through MLA and the corresponding single-line acquisition (SLA). The network achieves a significant improvement in image quality for both $5-$ and $7-$line MLA resulting in a decorrelation measure similar to that of SLA while having the frame rate of MLA.Comment: To appear in the Proceedings of MICCAI, 201

A note on the extension of the polar decomposition for the multidimensional Burgers equation

It is shown that the generalizations to more than one space dimension of the pole decomposition for the Burgers equation with finite viscosity and no force are of the form u = -2 viscosity grad log P, where the P's are explicitly known algebraic (or trigonometric) polynomials in the space variables with polynomial (or exponential) dependence on time. Such solutions have polar singularities on complex algebraic varieties.Comment: 3 pages; minor formatting and typos corrected. Submitted to Phys. Rev. E (Rapid Comm.