Publications (7)
Graph Expansion Analysis for Communication Costs of Fast Rectangular Matrix Multiplication
Grey Ballard, James Demmel, Olga Holtz +2
Graph expansion analysis of computational DAGs is useful for obtaining communication cost lower bounds where previous methods, such as geometric embedding, are not applicable. This…
Parallelizing Gaussian Process Calculations in R
Christopher J. Paciorek, Benjamin Lipshitz, Wei Zhuo +3
We consider parallel computation for Gaussian process calculations to overcome computational and memory constraints on the size of datasets that can be analyzed. Using a hybrid par…
Improving the numerical stability of fast matrix multiplication
Grey Ballard, Austin R. Benson, Alex Druinsky +2
Fast algorithms for matrix multiplication, namely those that perform asymptotically fewer scalar operations than the classical algorithm, have been considered primarily of theoreti…
Communication-Optimal Parallel Algorithm for Strassen's Matrix Multiplication
Grey Ballard, James Demmel, Olga Holtz +2
Parallel matrix multiplication is one of the most studied fundamental problems in distributed and high performance computing. We obtain a new parallel algorithm that is based on St…
Fresh Content Needs More Attention: Multi-funnel Fresh Content Recommendation
Jianling Wang, Haokai Lu, Sai zhang +10
Recommendation system serves as a conduit connecting users to an incredibly large, diverse and ever growing collection of contents. In practice, missing information on fresh (and t…
Strong Scaling of Matrix Multiplication Algorithms and Memory-Independent Communication Lower Bounds
Grey Ballard, James Demmel, Olga Holtz +2
A parallel algorithm has perfect strong scaling if its running time on P processors is linear in 1/P, including all communication costs. Distributed-memory parallel algorithms for…