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Stencil computations are widely used to simulate the change of state of physical systems across a multidimensional grid over multiple timesteps. The state-of-the-art techniques in this area fall into three groups: cache-aware tiled looping algorithms, cache-oblivious divide-and-conquer trapezoidal algorithms, and Krylov subspace methods. In this paper, we present two efficient parallel algorithms for performing linear stencil computations. Current direct solvers in this domain are computationally inefficient, and Krylov methods require manual labor and mathematical training. We solve these problems for linear stencils by using DFT preconditioning on a Krylov method to achieve a direct solver which is both fast and general. Indeed, while all currently available algorithms for solving general linear stencils perform Θ(NT) work, where N is the size of the spatial grid and T is the number of timesteps, our algorithms perform o(NT) work. To the best of our knowledge, we give the first algorithms that use fast Fourier transforms to compute final grid data by evolving the initial data for many timesteps at once. Our algorithms handle both periodic and aperiodic boundary conditions, and achieve polynomially better performance bounds (i.e., computational complexity and parallel runtime) than all other existing solutions. Initial experimental results show that implementations of our algorithms that evolve grids of roughly 10^7 cells for around 10^5 timesteps run orders of magnitude faster than state-of-the-art implementations for periodic stencil problems, and 1.3× to 8.5× faster for aperiodic stencil problems.
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StEER 2020 Hurricane Delta Field Assessment Structural Team Dataset: FAST 1 and FAST 2
The response leveraged small, self-contained, regional FASTs deploying in phases to collect rapid assessment data using vehicle-mounted street-level panoramic imaging platforms, with select use of UAS. Routes were selected to ensure longitudinal data capture of areas previously documented for Hurricane Laura, as well as new clusters exposed to some of the Delta’s highest wind speeds to the east of landfall.
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- Award ID(s):
- 2103550
- PAR ID:
- 10513727
- Publisher / Repository:
- Designsafe-CI
- Date Published:
- Subject(s) / Keyword(s):
- Planning Documents Unmanned Aerial Systems Daily Summaries Other Ground-Based Observations GPS Data Surface-Level Panoramic Imagery
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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