171 citations · 329 across the 11 of their papers we have counts for
12 papers
A Portable and Versatile Limited-Memory BFGS Implementation in PETSc/TAO
Hansol Suh, Tobin Isaac, Alp Dener +3
The limited-memory BFGS (L-BFGS) Hessian update scheme is the critical kernel in many quasi-Newton optimization algorithms. The most common approach to implementing L-BFGS uses $2m…
Robust Expected Information Gain for Optimal Bayesian Experimental Design Using Ambiguity Sets
Jinwoo Go, Tobin Isaac
The ranking of experiments by expected information gain (EIG) in Bayesian experimental design is sensitive to changes in the model's prior distribution, and the approximation of EI…
Inferring ice sheet damage models from limited observations using CRIKit: the Constitutive Relation Inference Toolkit
Grant Bruer, Tobin Isaac
We examine the prospect of learning ice sheet damage models from observational data. Our approach, implemented in CRIKit (the Constitutive Relation Inference Toolkit), is to model…
Recursive, parameter-free, explicitly defined interpolation nodes for simplices
Tobin Isaac
A rule for constructing interpolation nodes for th degree polynomials on the simplex is presented. These nodes are simple to define recursively from families of 1D node sets, su…
A mixed finite element for weakly-symmetric elasticity
Tobin Isaac
We develop a finite element discretization for the weakly symmetric equations of linear elasticity on tetrahedral meshes. The finite element combines, for , discontinuous…
Landau Collision Integral Solver with Adaptive Mesh Refinement on Emerging Architectures
M. F. Adams, E. Hirvijoki, M. G. Knepley +3
The Landau collision integral is an accurate model for the small-angle dominated Coulomb collisions in fusion plasmas. We investigate a high order accurate, fully conservative, fin…
Strong Scaling for Numerical Weather Prediction at Petascale with the Atmospheric Model NUMA
Andreas Müller, Michal A. Kopera, Simone Marras +3
Numerical weather prediction (NWP) has proven to be computationally challenging due to its inherent multiscale nature. Currently, the highest resolution NWP models use a horizontal…
Support for Non-conformal Meshes in PETSc's DMPlex Interface
Tobin Isaac, Matthew G. Knepley
PETSc's DMPlex interface for unstructured meshes has been extended to support non-conformal meshes. The topological construct that DMPlex implements---the CW-complex---is by defini…
Bounds on the number of discontinuities of Morton-type space-filling curves
Carsten Burstedde, Johannes Holke, Tobin Isaac
The Morton- or z-curve is one example for a space filling curve: Given a level of refinement L, it maps the interval [0, 2**dL) one-to-one to a set of d-dimensional cubes of edge l…
Scalable and efficient algorithms for the propagation of uncertainty from data through inference to prediction for large-scale problems, with application to flow of the Antarctic ice sheet
Tobin Isaac, Noemi Petra, Georg Stadler +1
The majority of research on efficient and scalable algorithms in computational science and engineering has focused on the forward problem: given parameter inputs, solve the governi…
Solution of nonlinear Stokes equations discretized by high-order finite elements on nonconforming and anisotropic meshes, with application to ice sheet dynamics
Tobin Isaac, Georg Stadler, Omar Ghattas
Motivated by the need for efficient and accurate simulation of the dynamics of the polar ice sheets, we design high-order finite element discretizations and scalable solvers for th…
Recursive Algorithms for Distributed Forests of Octrees
Tobin Isaac, Carsten Burstedde, Lucas C. Wilcox +1
The forest-of-octrees approach to parallel adaptive mesh refinement and coarsening (AMR) has recently been demonstrated in the context of a number of large-scale PDE-based applicat…