Keywords: Noise mapping Grid refinement Uncertainty Interpolation GIS Noise maps are usually represented as contour or isolines maps describing the sound levels in a region. Using this kind of representation the user can easily find the noise level assigned to every location in the map. But the acoustic calculations behind the map are not performed for every single location on it; they are only...

ÐQuadtree-based adaptive Cartesian/Quad (quadrilateral) grid generator, grid adaptor and ̄ow solver have been developed and fully demonstrated in this study. Given the de®nition of geometries (cubic B-splines and straight line segments), geometrically-adaptive, body-®tted Quad grids are generated automatically. These grids are then overlapped with a large Cartesian cell which is subdivided recur...

In this paper we present an adaptive projection method for modeling unsteady, lowMach reacting flow in an unconfined region. The equations we solve are based on a model for low-Mach number combustion that consists of the evolution equations for density, species concentrations, enthalpy, and momentum coupled with a constraint on the divergence of the flow. The algorithm is based on a projection ...

Grandin, M. 2014. Adaptive Solvers for High-Dimensional PDE Problems on Clusters of Multicore Processors. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1199. 34 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9095-9. Accurate numerical solution of time-dependent, high-dimensional partial differential equations (PDEs) usually req...

The data grid integrates wide-area autonomous data sources and provides users with a unified data query and processing infrastructure. Adapt data query and processing is required by data grids to provide better quality of services (QoS) to users and applications in spite of dynamically changing resources and environments. Existing AQP techniques can only meet partially data grid requirements. S...

fficient ray tracing has been a contradiction in terms since its introduction as a computer version of ideas found in Dürer's Underweysung der Messung (1525) and Descartes' La Dioptrique (1637). The most effective acceleration techniques developed to reduce ray tracing's high computational cost are based on space coherence: bounding box hierarchies and space subdivision. 1 During pre-processing...

We consider piecewise polynomial approximation of order M in N-dimensions with a tensor product partition of the space. We assume that the partition is to be chosen to minimize ------'the-maximum----em>r---in-the-approximation.------1be---optimal---Iate---gf--cgrwetgence-foyieGeWisef--------polynomial approximation to a smooth function for unconstrained partitions is known to be order ~/N where...

We are developing multigrid methods that will efficiently solve elliptic problems with anisotropic and discontinuous coefficients on adaptive grids. The final product will be a library that provides for the simplified solution of such problems. This library will directly benefit the efforts of other Laboratory groups. The focus of this work is research on serial and parallel elliptic algorithms...

Grids offer a dramatic increase in the number of available processing and storing resources that can be delivered to applications. However, efficient job submission and management continue being far from accessible to ordinary scientists and engineers due to their dynamic and complex nature. This paper describes a new Globus based framework that allows an easier and more efficient execution of ...

Algorithmic skeletons abstract commonly used patterns of parallel computation, communication, and interaction. By demonstrating a predictable communication and computation structure, they provide a foundation for performance modelling and estimation. Grids pose a challenge to known distributed systems techniques as a result of their dynamism. One of the most prominent research areas concerns th...