630 likes | 909 Views
Tsunami Modeling with Graphics Processing Unit (GPU) and Radial Basis Functions (RDF). DAVID A. YUEN Minnesota Supercomputing Institute,University of Minnesota, Minnesota JESSICA SCHMIDT Saint Scholastica College, Duluth, Minnesota ERIK O.D. SEVRE
E N D
Tsunami Modeling with Graphics Processing Unit (GPU) and Radial Basis Functions (RDF) DAVID A. YUEN Minnesota Supercomputing Institute,University of Minnesota, Minnesota JESSICA SCHMIDT Saint Scholastica College, Duluth, Minnesota ERIK O.D. SEVRE Minnesota Supercomputing Institute University of Minnesota, Minnesota NAN ZHANG Medical School, University of Minnesota Minnesota GRADY B. WRIGHT Dept. of Mathematics , Boise State University, Boise, Idaho JESSICA SCHMIDT Saint Scholastica College, Duluth, Minnesota CECIL PIRET Institute of Applied Mathematics for Geosciences, National Center of Atmospheric Research, Boulder, Colorado SPRING LIU Minnesota Supercomputing Institute University of Minnesota, Minnesota NATASHA FLYER Institute of Applied Mathematics for Geosciences, National Center for Atmospheric Research, Boulder, Colorado
Outline • Introduction to Tsunamis and Tsunami Modeling • Visualization of tsunamis with Amira visualization package • Virtues of Graphics Accelerated Board (GPU) • Applications of GPU to Shallow-Water equations • Radial Basis Functions (RBF) Swirling Flows • Applications of GPU to RBF equations • Concluding Remarks
What is a Tsunami? (soo-NAH-mee)
Most of the waves present on the ocean’s surface are wind-generated waves. Wave types Wave in the Ocean Size and type of wind-generated waves are controlled by: Wind velocity, Wind duration, Fetch, and Original state of sea surface.
Tsunamis consist of a series of long-period waves characterized by very long wave length (up to 100 km) and high speed (up to 760 km/hr) in the deep ocean. Because of their large wave length, tsunamis are shallow-water to intermediate-water waves as they travel across the ocean basin. They only become DANGEROUS, when reaching coastal areas where wave height can reach 10 m. Tsunamis originate from earthquakes, volcanic explosions, or submarine landslides. 7-5 Tsunami
Background Numerical Tsunami Modeling Tsunami Sources in the world (2180 events from 1628BC to 2005)
Background Seismic Tsunami Modelling Killer Tsunamis in Historical Times
General Tsunami Modelling Displacement Field (initial Condition) Propagation (Linear and Nonlinear model) Run-up 1 Physical Analysis 2Numerical Simulation 3 Visualization 4 Result Analysis and Digestion
Seismic Tsunami Modelling Navier-Stokes Equations System Boussinesq Equations Shallow Water Equations Seismic Tsunami Modelling 1 Analyze the phenomenon (Local and Far-field) 2 Choose Coordinates 3 Choose the equations 4 solution of grid Etopo1, Etopo2, Strm30, or local bathymetry data The initial wave( From earthquake) 5 Boundary and initial conditions 6 Visualization Satellite data or tidal data 7Analysis results
Introduction of Amira Amira is a powerful, multifaceted software platform for visualizing, manipulating, and understanding scientific data coming from a all types of sources and modalities. Multi purpose - One tool for interdisciplinary work Flexible - Option packages to configure amira to your needs Efficient - Exploits latest graphics cards and processors Easy to use - Intuitive user interface and great documentation Cost effective - Multiple options and flexible license models Handling large data - Very large data sets are easily accessible with specific readers Extensible - C++ coding wizard for technical extension and customization Support - Customer direct support with high level of interaction Innovative - Technology always up dated to the latest innovation
Highlight of Visualization with Amira 3 This figure shows the height field with a scaled height.
Wave Propagation Visualization of Tsunami Modeling- Eastern China Sea
Wave Propagation Visualization of Tsunami Modeling- Solomon Islands
Wave Propagation Comparison of Linear and Nonlinear Modeling
Different Bathymetry Resolution Comparison of Nonlinear Modeling on Shallow Part of the Ocean Part Grids: 1201*1201 601*601
Conclusion (1) Visualization promotes a rapid understanding of the waves' paths from initial stages ; influences from the initial surroundings(2) Visualization Allows us to understand better the subsequent events when the waves are interacting with the coastline and off-shore islands(3) Visualization Helps to teach people about wave propagation for local and regional scenarios
TSUNAMI SIMULATION WITH GPU PROGRAMMING JESSICA SCHMIDT from computer science and mathematics UNDERGRADUATE SUMMER INTERN
Jessica Schmidt Undergraduate summer intern Tsunami Simulation with GPU Programming
Overview • Why we do this project? • GPU with CUDA programming • Tsunami Simulation with CUDA • RBF ( RADIAL BASIS FUNCTIONS ) Summary • What does the future hold?
Viable set-up for real-time tsunami visualization By Jessica Seismology Tsunami Simulation with GPU Programming Earthquake Real Tsunami Visualization (Interface Window) Bathymetric Data Tsunami By Erik Tsunami Warning
GPU • Graphics Processing Unit • Much faster than CPU now • Getting more expensive, can easily now • Outstrip the cost of a laptop itself • Takes the load off of the CPU • Computes many complex math problems • Faster graphics processing speed • Increased detailed and complexity without compromising performance
CUDA Benefits Drawbacks • Compute Unified Device Architecture • Developed by NVIDIA • Based on C Takes load off CPU Easy to learn and implement Difficult to find video card , MAC is cooler for this .
GPU Specs. • There are other GPUs that work with CUDA as well. • NVIDIA GeForce 8000 and above • NVIDIA Quadro, DELUXE MODEL • NVIDIA Tesla
Jessica’s Job This Summer • Covert linear tsunami codes • Spring Liu ----second Finite Difference Method • Cecile Piret ---- Radial Basis Function (RBF) • Implement CUDA for Spring’s and Cecile’s linear codes, then see if there is speedup
2-DShallowWaterEquations Linear Non-Linear M, N = mass fluxes in horizontal plane z = wave height t = time h = ocean water depth D = total water depth, D = z + h ρ = density τx, τy = shear stress along x and y axis
Flow Chart: Bathymetric Data: Etopo1 Parameters of Rupture: From HARVARD Database , Miyaki Ishii Visualization: Amira
Radial Basis Functions (RBF) Method An Introduction
The RBF method 70s Rolland Hardy introduces a new method for scattered data interpolation for geological data, the MQ method, so named for its use as basis of the multi-quadric function. First published in JGR 70s-80s The method is generalized to more radial functions. It is renamed the “Radial Basis Functions (or RBF) method”. 90s Ed Kansa from UC Davis uses the RBF method to solve partial differential equations.
The RBF method • Given scattered data • Define the RBF interpolant
The RBF method • Given scattered data • Define the RBF interpolant
The RBF method • Given scattered data • Define the RBF interpolant • Find by solving the system
The RBF method Coding the RBF method is fast and easy RBF part of the code
+ Interpolation on scattered data. No grid necessary. Very easy implementation in N-dimensions. The basis functions are not orthogonal with each other, but we are guaranteed a non-singular system for most types of RBFs. Spectral accuracy for infinitely smooth radial functions - High complexity. No fast algorithm. The RBF method
Radial Basis Functions (RBF)--- Cecile • Interpolating data takes the form: • Use RBFs to model 2-D linear waves • Cecile Piret wrote simulations using Matlab • Convert to GPU using Jacket – developed by Accelereyes
The comparison of GPU and CPU ------- Linear Tsunami Codes Spring’s linear tsunami code (21600 time steps) Cecile’s linear tsunami code (400 time steps) Lilli – an opteron-based system with 4 CPUs GPU – nVIDIA 8600M GT graphics card Laptop – standard MacBook Pro
Results for Tsunami Simulation beginning of simulation middle of simulation Simulation Movie