derniers depôts

Ajouté le 23/01/2019

Liquid films in steam turbines, present in usual operating conditions, play a large but poorly understood part in the wetness-born troubles (power losses and erosion). More knowledge is needed to estimate their impacts and lessen their effects. The aim of this paper is to propose and verify a model to predict these liquid films. This model is based on modified Shallow Water equations (integral formulation).

Ajouté le 23/01/2019

The combination of elliptical deformation of streamlines and vorticity can lead to the destabilization of any rotating flow via the elliptical instability. Such a mechanism has been invoked as a possible source of turbulence in planetary cores subject to tidal deformations.

Ajouté le 23/01/2019

We construct ergodic probability measures with infinite imetric entropy for typical continuous maps and homeomorphisms on compact manifolds. We also construct sequences of such measures that converge to a zero-entropy measure.

Ajouté le 22/01/2019

alpha-Oxoketenes generated in situ by a thermal Wolff rearrangement have been found to participate as 1,2-and 1,4-ambident C-electrophilic/O-nucleophilic reagents towards donor/acceptor carbonyl-stabilized Wittig ylides.

Ajouté le 19/01/2019

Given a (singular, codimension 1) holomorphic foliation F on a complex projective manifold X, we study the group PsAut(X, F) of pseudo-automorphisms of X which preserve F ; more precisely, we seek sufficient conditions for a finite index subgroup of PsAut(X, F) to fix all leaves of F. It turns out that if F admits a (possibly degenerate) transverse hyperbolic structure , then the property is satisfied; furthermore, in this setting we prove that all entire curves are algebraically degenerate.

Ajouté le 17/01/2019

This paper is devoted to the study of a controlled population of cells. The modelling of the problem leads to a mathematical formulation of stability and reachability properties of some controlled systems under uncertainties. We use the Hamilton-Jacobi (HJ) approach to address theses problems and to design a numerical method that we analyse on several numerical simulations.

Ajouté le 17/01/2019

We review the most recent advances in distributed optimal control applied to environmental economics, covering in particular problems where the state dynamics are governed by partial differential equations (PDEs). This is a quite fresh application area of distributed optimal control, which has already suggested several new mathematical research lines due to the specificities of the environmental economics problems involved.

Ajouté le 18/01/2019

The karst Tabular Middle Atlas Causses reservoir is the main drinking-water supply of Fez-Meknes region (Sais Basin) in Morocco. Recent analyses showed a decline in associated groundwater chemical quality and increased turbidity. To understand this hydrosystem, four surveys were undertaken during fall and spring, 2009-2011.

Ajouté le 17/01/2019

We study the problem of nonparametric estimation under L p-loss, p ∈ [1, ∞), in the framework of the convolution structure density model on R d. This observation scheme is a generalization of two classical statistical models , namely density estimation under direct and indirect observations. The original pointwise selection rule from a family of "kernel-type" estimators is proposed.

Ajouté le 16/01/2019

When navigating in a spatial environment or when hearing its description, we can develop a mental model which may be represented in the central nervous system in different coordinate systems such as an egocentric or allocentric reference frame. The way in which sensory experience influences the preferred reference frame has been studied with a particular interest for the role of vision. The present study investigated the influence of proprioception on human spatial cognition.