Samuel Li is an alumnus of the CDUX group, receiving his Ph.D. in November 2017. He accepted a full-time staff position at National Center for Atmospheric Research (NCAR) in September 2016, and continued in this position after graduation. His research interests include high-performance computing, portable performance, scientific data reduction for exascale computing, and scientific visualization.
Sam's dissertation question focused on the viability of wavelet compression as a reduction operator on exascale computers. This question required assessing viability from multiple perspectives. His first research thrust was on evaluating the integrity of scientific data sets after undergoing a wavelet transformation (LDAV15). In this work, Sam also demonstrated the benefit of bringing in modern wavelet approaches (CDF kernels and prioritized coefficients) for scientific data. Sam's second research thrust was on how to carry out wavelet transforms on exascale computers. Sam had two works on this front, one showing how to write portably performant code (EGPGV17) and another showing how to achieve better accuracy by leveraging deep memory hierarchies (CLUSTER17). Sam's final research thrust was on whether wavelet transformations could be accomplished within simulation codes' time budget, and evaluating their savings at scale. Sam studied this topic with his final dissertation work (ISAV17), which included runs of up to 1000 MPI ranks on NCAR's Cheyenne supercomputer. These works combined to answer his dissertation question: yes, wavelet compression is a viable reduction operator for exascale computing. Finally, Sam's Area Exam paper surveying data reduction operators was published at the Computer Graphics Forum journal.
Prior to joining UO, Samuel completed an M.S. degree from Tufts University, working with Remco Chang. His M.S. thesis was published as a research paper, Exploring Visualization Designs Using Phylogenetic Trees, at the SPIE Visualization and Data Analysis conference in 2015, and won a Best Paper award. During his time at UO, Samuel collaborated with John Clyne of NCAR, first as a summer student in 2015, and later through NCAR's Advanced Study Program (ASP) Award in Winter of 2016. Finally, Samuel did an internship at Los Alamos National Laboratory in the Summer of 2016, working with Chris Sewell, Ollie Lo, and Jon Woodring.