The dynamics of sheared inelastic-hard-sphere systems is studied using nonequilibrium molecular-dynamics simulations and direct simulation Monte Carlo. In the molecular-dynamics simulations Lees-Edwards boundary conditions are used to impose the shear. The dimensions of the simulation box are chosen to ensure that the systems are homogeneous and that the shear is applied uniformly. Various syst...

In this article we study the effects of introducing structure in the input distribution of the data to be learnt by a simple perceptron. We determine the learning curves within the framework of Statistical Mechanics. Stepwise generalization occurs as a function of the number of examples when the distribution of patterns is highly anisotropic. Although extremely simple, the model seems to captur...

The Besov characteristic of a distribution f is the function sf defined for 0 ≤ t < ∞ by sf (t) = sup{ s ∈ R; f ∈ B 1/t,1(Rn) }. We give in this paper a criterion for a function Γ defined on [0,+∞[ to be the Besov characteristic of a distribution. Generalizations of this criterion to particular weighted Besov spaces and to anisotropic Besov spaces are also given.

The effect of a statistically anisotropic distribution of stretched vortices in the LundgrenTownsend model of the fine-scale structure of homogeneous turbulence is considered. Lundgren’s argument that anisotropy does not affect the three-dimensional energy spectrum is confirmed. Examples of velocity derivative moments and one-dimensional vorticity spectra are worked out for the case of an axisy...

The focus of this study is to estimate the contribution of regional anisotropic conductivity on the spatial distribution of an induced electric field across gray matter (GM), white matter (WM), and subcortical regions under transcranial direct current stimulation (tDCS). The assessment was conducted using a passive high-resolution finite element head model with inhomogeneous and variable anisot...

This work is concerned with some extensions of the classical compressible Euler model of fluid dynamics in which the fluid internal energy is a measure-valued quantity. A first extension was derived from the hydrodynamic limit of a kinetic model involving a specific class of collision operators typical from quasi-linear plasma theory (see Eur. J. Mech. B Fluids 20 (2001) 303–327, and Contin. Me...

[1] We present initial results from an equilibrium code that has been modified to include the effect of anisotropic pressures. This equilibrium code uses a frictional technique to iterate a set of modified MHD equations to equilibrium. We describe the modifications made to the original isotropic equilibrium code, including changes to the initial conditions that include a procedure to enforce th...

In a recent paper, Hyde et al. (1) explored the sensitivity of the EPR spectra of square-planar Cu*+ complexes to variations of the spin-Hamiltonian parameters by simulation of spectra both at the rigid limit and under a range of rotational correlation times. The purpose of this sensitivity analysis was to establish criteria for the optimum determination of the various parameters by simulation....

We develop an algorithm for reconstructing the triaxial shapes of dark matter halos from the anisotropic spatial distributions of their substructures. First, we construct an analytic model for the anisotropic spatial distributions of dark halo substructures under the assumption that the tidal field with non-zero trace in the triaxial mass distribution of the host halos generate the substructure...

The elastic properties of uniform polycrystalline materials without defects depend on both the constitutive properties of the constituents and the microstructural characteristics like the distribution of grain orientations and grain shapes. For an overview concerning the homogenization of elastic properties see, e.g., [1]. The elementary bounds by Voigt and Reuss take into account only the volu...