International audienceWe present an adaptive multiresolution method for the numerical simulation of ideal magnetohydrodynamics in two space dimensions. The discretization uses a finite volume scheme based on a Cartesian mesh and an explicit compact Runge–Kutta scheme for time integration. Harten's cell average multiresolution allows to introduce a locally refined spatial mesh while controlling the error. The incompressibility of the magnetic field is controlled by using a Generalized Lagrangian Multiplier (GLM) approach with a mixed hyperbolic–parabolic correction. Different applications to two-dimensional problems illustrate the properties of the method. For each application CPU time and memory savings are reported and numerical aspects of the method are discussed. The accuracy of the adaptive computations is assessed by comparison with reference solutions computed on a regular fine mesh

Résumé. Nous présentons une nouvelle méthode de multirésolution adaptative pour la simulation numérique de la magnétohydrodynamique idéale. Leséquations qui régissent la dynamique, i.e., leś equations d'Euler compressible couplées auxéquations de Maxwell sont discrétisées suivant un schéma de type volumes finis sur un maillage cartésien en deux dimensions. L'adaptativité en espace est obtenue en utilisant une analyse de multirésolution en moyenne de cellule proposée par Harten, qui est une méthode fiable pour le raffinement local du maillage tout en contrôlant l'érreur. La discrétisation temporelle est un schéma de Runge-Kutta qui intègre un contrôle automatique du pas de temps. Pour imposer l'incompressibilié du champs magnétique, une approche par multiplicateur de Lagrange généralisé est utilisée, ici de type parabolique-hyperbolique. Pour illustrer les capacitées de cette méthode, des applicationsà des problèmes de Riemann ontété réalisées. Les coûts en mémoire sont présentés, et la précision de la méthode estévaluée par comparaison avec les solutions exactes du problème.Abstract. We present a new adaptive multiresoltion method for the numerical simulation of ideal magnetohydrodynamics. The governing equations, i.e., the compressible Euler equations coupled with the Maxwell equations are discretized using a finite volume scheme on a two-dimensional Cartesian mesh. Adaptivity in space is obtained via Harten's cell average multiresolution analysis, which allows the reliable introduction of a locally refined mesh while controlling the error. The explicit time discretization uses a compact Runge-Kutta method for local time stepping and an embedded Runge-Kutta scheme for automatic time step control. An extended generalized Lagrangian multiplier approach with the mixed hyperbolic-parabolic correction type is used to control the incompressibility of the magnetic field. Applications to a two-dimensional problem illustrate the properties of the method. Memory savings and numerical divergences of magnetic field are reported and the accuracy of the adaptive computations is assessed by comparing with the available exact solution. Article published online by EDP Sciences and available at http://www.esaim-proc.org or http://dx

Computational magnetohydrodynamics (MHD) for space physics has become an essential area in understanding the multiscale dynamics of geophysical and astrophysical plasma processes, partially motivated by the lack of space data. Full MHD simulations are typically very demanding and may require substantial computational efforts. In particular, computational space-weather forecasting is an essential long-term goal in this area, motivated for instance by the needs of modern satellite communication technology. We present a new feature of a recently developed compressible two-and three-dimensional MHD solver, which has been successfully implemented into the parallel AMROC (Adaptive Mesh Refinement in Object-oriented C++) framework with improvements concerning the mesh adaptation criteria based on wavelet techniques. The developments are related to computational efficiency while controlling the precision using dynamically adapted meshes in space-time in a fully parallel context.

We present an adaptive parallel solver for the numerical simulation of ideal magnetohydrodynamics in two and three space dimensions. The discretisation uses a finite volume scheme based on a Cartesian mesh and an explicit compact Runge-Kutta scheme for time integration. Numerically, a generalized Lagrangian multiplier approach with a mixed hyperbolic-parabolic correction is used to guarantee a control on the incompressibility of the magnetic field. We implement the solver in the AMROC (Adaptive Mesh Refinement in Object-oriented C++) framework that uses a structured adaptive mesh refinement (SAMR) method discretisation-independent and is fully parallelised for distributed memory systems. Moreover, AMROC is a modular framework providing manageability, extensibility and efficiency. In this paper, we give an overview of the ideal magnetohydrodynamics solver developed in this framework and its capabilities. We also include an example of this solver's verification with other codes and its numerical and computational performance.

In several companies, transportation costs are most part logistics costs. In this context, the appropriate distribution planning figures as a strategic activity in the generation of competitiveness. Previous studies that analyzed the transportation problem do not consider the role of the expedition in their models. This research investigated a transportation problem considering the expedition of goods. A midsize retailer located in the ABC region of Sao Paulo was used to conduct a case study. In addition to documentary data, interviews were conducted with professionals involved in the expedition operation. The results indicated that the company could optimize their expedition by considering the changes proposed in this study. We conclude that the expedition is an important activity in the analysis of a transport model.

In several companies, transportation costs are most part logistics costs. In this context, the appropriate distribution planning figures as a strategic activity in the generation of competitiveness. Previous studies that analyzed the transportation problem do not consider the role of the expedition in their models. This research investigated a transportation problem considering the expedition of goods. A midsize retailer located in the ABC region of Sao Paulo was used to conduct a case study. In addition to documentary data, interviews were conducted with professionals involved in the expedition operation. The results indicated that the company could optimize their expedition by considering the changes proposed in this study. We conclude that the expedition is an important activity in the analysis of a transport model.

ABSTRACT. This work is concerned with the numerical simulation of the Kelvin-Helmholtz instability using an ideal and resistive two-dimensional magnetohydrodynamics model in the context of an adaptive multiresolution approach. The Kelvin-Helmholtz instabilities are caused by a velocity shear and normally expected in a layer between two fluids with different velocities. Due to its complexity, this kind of problem is a well-known test for numerical schemes and it is important for the verification of the developed code. The aim of this paper is to verify the implemented numerical model with the well-known astrophysics FLASH code.

Logistics has become a strategic activity along the time not only a mere operational task in corporations, for that reason having a suitable management for logistics processes bring benefits all over the companies and impacts customer satisfaction. This paper was developed based on a case study performed in a packaging company located in the east area of the city of São Paulo, it was conducted in the period from April to September of 2017. An evaluation of logistical processes was performed based on non-participative observations and posteriorly with participative observations, with the diagnosis of main problems corrective actions were implemented as well as processes control. A training program was done to prepare the workers to accomplish with the new procedures, that made possible to stablish a comparison between past results and the ones achieved with new procedures and controls.   It was also proposed and utilized the Net Promoter Score – NPS method to evaluate customer satisfaction that allowed to observe the results evolution achieved with the new procedures implemented.