Contact

Johann Rudi
Assistant Professor
Department of Mathematics
Virginia Tech
225 Stanger Street
Blacksburg, VA 24061, USA
Office: 302 Data & Decision Sciences (D&DS) Building
E-mail:

Publications / Theses

[1]
Y. Curtis Wang, Johann Rudi, James Velasco, Nirvik Sinha, Gideon Idumah, Randall K. Powers, Charles J. Heckman, and Matthieu K. Chardon, Multimodal Parameter Spaces of a Complex Multi-Channel Neuron Model, Frontiers in Systems Neuroscience 16, 2022, 1–18. [doi: 10.3389/fnsys.2022.999531 | bioRxiv]

[2]
Anshu Dubey, Klaus Weide, Jared O'Neal, Akash Dhruv, Sean Couch, J. Austin Harris, Tom Klosterman, Rajeev Jain, Johann Rudi, Bronson Messer, Michael Pajkos, Jared Carlson, Ran Chu , Mohamed Wahib, Saurabh Chawdhary, Paul M. Ricker, Dongwook Lee , Katie Antypas, Katherine M. Riley, Christopher Daley, Murali Ganapathy, Francis X. Timmes, Dean M. Townsley, Marcos Vanella, John Bachan, Paul M. Rich, Shravan Kumar, Eirik Endeve, W. Raphael Hix, Anthony Mezzacappa, and Thomas Papatheodore, Flash-X: A Multiphysics Simulation Software Instrument, Software-X 19, 2022, 1–7. [doi: 10.1016/j.softx.2022.101168]

[3]
Johann Rudi, Michael Gurnis, and Georg Stadler, Simultaneous Inference of Plate Boundary Stresses and Mantle Rheology Using Adjoints: Large-Scale Two-Dimensional Models, Geophysical Journal International 231, 2022, 597–614. [doi: 10.1093/gji/ggac207 | EarthArXiv: 2833]

[4]
Jiashun Hu, Michael Gurnis, Johann Rudi, Georg Stadler, and R. Dietmar Müller, Dynamics of the Abrupt Change in Pacific Plate Motion Around 50 Ma, Nature Geoscience 15, 2022, 74–78. [doi: 10.1038/s41561-021-00862-6]

[5]
Jared O'Neal, Mohamed Wahib, Anshu Dubey, Klaus Weide, Tom Klosterman, and Johann Rudi, Domain-Specific Runtime to Orchestrate Computation on Heterogeneous Platforms, in Euro-Par 2021: Parallel Processing Workshops, 2022. [doi: 10.1007/978-3-031-06156-1_13]

[6]
Amanda Lenzi, Julie Bessac, Johann Rudi, and Michael L. Stein, Neural Networks for Parameter Estimation in Intractable Models, submitted, 2021. [arXiv: 2107.14346]

[7]
Johann Rudi, Jared O'Neal, Mohamed Wahib, and Anshu Dubey, CodeFlow: A Code Generation System for Flash-X Orchestration Runtime, Technical Report ANL-21/17, Argonne National Laboratory, Lemont, IL, 2021. [osti: 1778932]

[8]
Johann Rudi, Julie Bessac, and Amanda Lenzi, Parameter Estimation with Dense and Convolutional Neural Networks Applied to the FitzHugh-Nagumo ODE, in Proceedings of Machine Learning Research vol 145: 2nd Annual Conference on Mathematical and Scientific Machine Learning, 2021. [PMLR pdf | arXiv: 2012.06691]

[9]
Johann Rudi, Yu-hsuan Shih, and Georg Stadler, Advanced Newton Methods for Geodynamical Models of Stokes Flow with Viscoplastic Rheologies, Geochemistry, Geophysics, Geosystems 21, 2020, e2020GC009059. [arXiv: 2003.11115 | doi: 10.1029/2020GC009059]

[10]
Johann Rudi, Global Convection in Earth’s Mantle: Advanced Numerical Methods and Extreme-Scale Simulations, Doctoral Thesis, The University of Texas at Austin, USA, 2018. [doi: 10.26153/tsw/1258]

[11]
Johann Rudi, Georg Stadler, and Omar Ghattas, Weighted BFBT Preconditioner for Stokes Flow Problems with Highly Heterogeneous Viscosity, SIAM Journal on Scientific Computing 39, 2017, S272–S297. [arXiv: 1607.03936 | doi: 10.1137/16M108450X]

[12]
Johann Rudi, A. Cristiano I. Malossi, Tobin Isaac, Georg Stadler, Michael Gurnis, Peter W. J. Staar, Yves Ineichen, Costas Bekas, Alessandro Curioni, and Omar Ghattas, An Extreme-Scale Implicit Solver for Complex PDEs: Highly Heterogeneous Flow in Earth's Mantle, Winner of ACM Gordon Bell Prize 2015, in SC '15: Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis, 2015. [pdf | doi: 10.1145/2807591.2807675 | visualization movie]

[13]
Hari Sundar, George Biros, Carsten Burstedde, Johann Rudi, Omar Ghattas, and Georg Stadler, Parallel Geometric-Algebraic Multigrid on Unstructured Forests of Octrees, in SC '12: Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis, 2012. [pdf | doi: 10.1109/SC.2012.91]

[14]
Johann Rudi, Ronald Pabel, Gabriela Jager, Robin Koch, Angela Kunoth, and Heye Bogena, Multiscale Analysis of Hydrologic Time Series Data Using the Hilbert-Huang Transform (HHT), Vadose Zone Journal 9, 2010, 925–942. [pdf | doi: 10.2136/vzj2009.0163]

[15]
Johann Rudi, Empirical Mode Decomposition via adaptiver Wavelet-Approximation (German), Diploma Thesis, Universität Paderborn, Germany, 2010. [pdf]

Presentations

SIAM CSE
Scalable Inference of Non-Newtonian Rheology Parameters in Earth's Mantle on HPC Platforms, joint work with: Georg Stadler, Jiashun Hu, Micheal Gurnis, SIAM Conference on Computational Science and Engineering (CSE23), Amsterdam, Netherlands, March 2, 2023. [slides]
SIAM UQ
Inverse Maps Based on Deep Neural Networks for Inverse Problems with Challenging Physical Models, joint work with: Julie Bessac, German Villalobos, Andreas Mang, SIAM Conference on Uncertainty Quantification (UQ22), Virtual, April 15, 2022. [slides]
SIAM PP
Transformation from DSL to Source Code for Multi-Physics Simulations with Flash-X, joint work with: Mohamed Wahib, Jared O'Neal, Anshu Dubey, SIAM Conference on Parallel Processing for Scientific Computing (PP22), Virtual, February 26, 2022. [slides]
SIAM PP
Composable Streamed Interfaces in PETSc for Extreme-Scale Geometric Multigrid, joint work with: Barry Smith, SIAM Conference on Parallel Processing for Scientific Computing (PP20), Seattle, Washington, February 13, 2020. [poster]
MCS ANL
Inference of Uncertain Parameters in Physical Models Governed by PDEs with Application to Earth’s Mantle Convection, joint work with: Georg Stadler, Jiashun Hu, Michael Gurnis, and Omar Ghattas, Seminar talk at Mathematics and Computer Science Division, Argonne National Laboratory, January 22, 2020. [slides]
AGU
Global Convection in Earth's Mantle: Advanced Numerical Methods for Forward and Inverse Modeling, joint work with: Georg Stadler, Jiashun Hu, Michael Gurnis, and Omar Ghattas, AGU 2019, San Francisco, California, December 11, 2019. [slides]
An Optimization-Based Perturbed Newton Method for Viscoplastic Fluids with von Mises Yielding, joint work with: Georg Stadler and Omar Ghattas, Preconditioning 2019, Minneapolis, Minnesota, July 3, 2019. [slides]
SIAM CSE19
Improved Newton Linearization for L1-Norm-Type Minimization with Application to Viscoplastic Fluid Solvers, joint work with: Georg Stadler and Omar Ghattas, SIAM Conference on Computational Science & Engineering (CSE19), Spokane, Washington, February 26, 2019. [poster]
SIAM PP18
An Extreme-Scale Implicit Solver for Highly Nonlinear and Heterogeneous Flow in Earth's Mantle, joint work with: Georg Stadler and Omar Ghattas, SIAM Conference on Parallel Processing for Scientific Computing (PP18), Tokyo, Japan, March 10, 2018. [slides | minisymposium info]
SIAM CSE17
Scalable Spectral-Geometric-Algebraic Multigrid and Schur Complement Preconditioning for Nonlinear, Multiscale, Heterogeneous Flow in Earth's Mantle, joint work with: Georg Stadler, A. Cristiano I. Malossi, Tobin Isaac, Michael Gurnis, Peter W. J. Staar, Yves Ineichen, Costas Bekas, Alessandro Curioni, and Omar Ghattas, SIAM Conference on Computational Science & Engineering (CSE17), Atlanta, Georgia, March 3, 2017. [slides | play recording | minisymposium info]
ISC 2016
An Extreme-Scale Implicit Solver for Complex PDEs: Hybrid Spectral-Geometric-Algebraic Multigrid for Highly Heterogeneous Flow in Earth's Mantle, joint work with: A. Cristiano I. Malossi, Tobin Isaac, Georg Stadler, Michael Gurnis, Peter W. J. Staar, Yves Ineichen, Costas Bekas, Alessandro Curioni, and Omar Ghattas, ISC 2016, Frankfurt, Germany, June 22, 2016. [slides]
SIAM PP16
Extreme-Scale Solver for Earth's Mantle – Spectral-Geometric-Algebraic Multigrid Methods for Nonlinear, Heterogeneous Stokes Flow, joint work with: A. Cristiano I. Malossi, Tobin Isaac, Georg Stadler, Michael Gurnis, Peter W. J. Staar, Yves Ineichen, Costas Bekas, Alessandro Curioni, and Omar Ghattas, SIAM Conference on Parallel Processing for Scientific Computing (PP16), Paris, France, April 13, 2016. [slides | minisymposium info]
mu-BFBT Preconditioner for Stokes Flow Problems with Highly Heterogeneous Viscosity, Student Paper Competition Winner, joint work with: Georg Stadler and Omar Ghattas, 14-th Copper Mountain Conference on Iterative Methods, Copper Mountain, Colorado, USA, March 24, 2016. [slides]
Scalable Parallel Solvers for Highly Heterogeneous Nonlinear Stokes Flow Discretized with Adaptive High-Order Finite Elements, 26-th Robert J. Melosh Medal Finalists Symposium, Duke University, Durham, North Carolina, USA, April 24, 2015. [slides]
SIAM CSE15
Scalable Parallel Solvers for Highly Heterogeneous Nonlinear Stokes Flow Discretized with Adaptive High-Order Finite Elements, joint work with: Tobin Isaac, Georg Stadler, Micheal Gurnis, and Omar Ghattas, SIAM Conference on Computational Science & Engineering (CSE15), Salt Lake City, Utah, USA, March 16, 2015. [poster]
SC14
Parallel High-Order Geometric Multigrid Methods on Adaptive Meshes for Highly Heterogeneous Nonlinear Stokes Flow Simulations of Earth's Mantle, Best Poster Award, joint work with: Hari Sundar, Tobin Isaac, Georg Stadler, Micheal Gurnis, and Omar Ghattas, SC '14: The International Conference for High Performance Computing, Networking, Storage and Analysis, New Orleans, Louisiana, USA, November 18, 2014. [poster]
Parallel High-Order Geometric Multigrid Methods on Adaptive Meshes for Highly Heterogeneous Nonlinear Stokes Flow Simulations of Earth’s Mantle, joint work with: Hari Sundar, Tobin Isaac, Georg Stadler, Micheal Gurnis, and Omar Ghattas, ICES Student Forum, Austin, Texas, USA, November 14, 2014. [poster]
SIAM AN14
Plate Boundary-Resolving Nonlinear Global Mantle Flow Simulations Using Parallel High-Order Geometric Multigrid Methods on Adaptive Meshes, joint work with: Hari Sundar, Tobin Isaac, Georg Stadler, Micheal Gurnis, and Omar Ghattas, 2014 SIAM Annual Meeting, Chicago, Illinois, USA, July 7, 2014. [slides | play recording | minisymposium info]
SIAM CSE13
Adaptive High-Order Methods for Nonlinear Stokes Problems Arising in Mantle Flow, joint work with: Carsten Burstedde, Omar Ghattas, Micheal Gurnis, Tobin Isaac, Georg Stadler, and Hari Sundar, SIAM Conference on Computational Science & Engineering (CSE13), Boston, Massachusetts, USA, February 26, 2013. [poster]
RRW09
Empirical Mode Decomposition durch adaptive Wavelet-Approximation (German), joint work with: Angela Kunoth, 19th Rhein-Ruhr-Workshop on Applied Analysis, Approximation Theory, CAGD and Numerical Mathematics, Mühlheim an der Ruhr, Germany, February 6, 2009. [slides]