Although explicit time integration schemes require small computational efforts per time step, their efficiency is severely restricted by their stability limits. Indeed, the multi-scale nature of some physical processes combined with highly unstructured meshes can lead some elements to impose a severely small stable time step for a global problem. Multirate methods offer a way to increase the gl...

Recent progress is described on the unsolved problem of unfolding the surface of an orthogonal polyhedron to a single non-overlapping planar piece by cutting edges of the polyhedron. Although this is in general not possible, partitioning the faces into the natural vertex-grid may render it always achievable. Advances that have been made on various weakenings of this central problem are summariz...

The paper introduces an approach to bridging the gap between diverse data sources and software for visualization and data analysis. The possibility of XML-based languages for data structure description and the introduction of Grid services allows the possibility of partitioning the problem to straightforward components. The work takes place within gViz, a project within the UK escience Core Pro...

Many partitioning methods may be used to partition a network into smaller clusters while minimizing the number of cuts needed. However, other considerations must also be taken into account when a network represents a real system such as a power grid. In this paper we use a simulated annealing Monte Carlo (MC) method to optimize initial clusters on the Florida high-voltage power-grid network tha...

We study the efficiency of different alternatives for a scalable parallel implementation of the self-organizing map (SOM) in the GRID enviroment of variable resources and communications. In particular, we consider an application of data mining in Meteorology, which involves databases of high-dimensional atmospheric patterns. In this work, we focus in network partitioning alternatives, analyzing...

This paper presents new algorithms and data structures required for the generation of grids based on mixed element trees and using flexible refinement approach. Mixed elements trees is an extension of modified octrees that uses several well-shaped primitives such as cuboids, prisms, pyramids and tetrahedra as internal nodes. A flexible refinement approach fits the object geometry and fulfills t...

We propose an enhanced grid-density based approach for clustering high dimensional data. Our technique takes objects (or points) as atomic units in which the size requirement to cells is waived without losing clustering accuracy. For efficiency, a new partitioning is developed to make the number of cells ccepted 25 February 2011 vailable online 8 March 2011

Full wave electromagnetic simulation requires numerically expensive methods such as FDTD. The computation time depends superlinearly on the number of unknowns in the simulation region. In some situations, especially when the results are not needed at every point of the grid, simulation time can be reduced. This reduction can be accomplished by partitioning the grid into macromodels and determin...

Competitive numerical simulation codes solving partial differential equations have to tap the full potential of both modern numerical methods – like multi-grid and adaptive grid refinement – and available computing resources. In general, these two are rival tasks. Typically, hierarchical data structures resulting from multigrid and adaptive grid refinement impede efficient usage of modern memor...

We present a potential new partitioning mechanism for NAS-scale airspace that utilizes a high-resolution hexagonal grid. We use the Traffic Mass metric: total aircraft position report (“ETMS TZ hit”) count in each grid cell or airspace sector/center. Its relationship to Workload metrics is discussed. We describe a fast algorithm that processes large amounts of traffic data and creates potential...