The topological constraints imposed on a canonical transformation by the requirement of continuous connection to the identity are considered. In the case of a particle interacting with a periodic potential, it is shown that a transformation to normal form (new Hamiltonian independent of position) is in general impossible using a transformation satisfying this requirement; the best that can be d...

The paper presents a two-dimensional immersed interface technique for the vortex-in-cell (VIC) method for the simulation of flows past complex geometries. The particle–mesh VIC algorithm is augmented by a local particle– particle (PP) correction term in a particle–particle particle–mesh (PPPM) context to resolve sub-grid scales incurred by the presence of the immersed interface. The PP correcti...

Brownian motion plays an important role in the dynamics of colloidal suspensions. It affects rheological properties, influences the self-assembly of structures, and regulates particle transport. While including Brownian motion in simulations is necessary to reproduce and study these effects, it is computationally intensive due to the configuration dependent statistics of the particles’ random m...

Several works have pointed out that local dispersion plays a crucial role in determining the behavior of the concentration variance and coef¿cient of variation over time for conservative tracers. Numerical investigations aimed at evaluating the effect of the local dispersivity on dilution time scales are performed using a random-walk particle-tracking method model applied to transport of conser...

In this paper, a new numerical method for determining effective permittivity of dense random media in two dimensions is presented. The core of the method is to compare the average scattered field of a random collection of scatterers confined within an imaginary boundary with the scattered field from a homogeneous dielectric of the same shape as the imaginary boundary. The two-dimensional (2-D) ...

The core idea of cloud computing is managing and scheduling uniformly computing resources that are connected by a network to provide user services according to the needs. One of the important issues in this environment is related to task scheduling. The scheduler should do the scheduling process efficiently in order to utilize the available resources. In this paper, a particle swarm optimizatio...

The influence of aspect ratio and orientation to scattering properties of ellipsoid ice particles at 94GHz is studied by Discrete-Dipole Approximation (DDA) method. Absorption efficiency, scattering efficiency, asymmetry factor and backscattering efficiency are computed with aspect ratios vary from 0.2 to 1.0, whose size parameter range are selected from 0 to 5. It is found that the values of s...

We consider shock measures in a class of conserving stochastic particle systems on Z. These shock measures have a product structure with a step-like density profile and include a second class particle at the shock position. We show for the asymmetric simple exclusion process, for the exponential bricklayers’ process, and for a generalized zero range process, that under certain conditions these ...

Recent laser technology provides accurate measures of the dynamics of fluids and embedded particles. For instance, the laser-extinction measurements (LEM) uses a laser beam passing across the fluid and measures the residual laser light intensity at the fluid output. The particle concentration is estimated from this measurement. However, the particle flow is submitted to random time-varying fluc...