Advances in Applied Computer Science Invited Speaker Series

Host: Patrick Diehl
Co-Host: Philipp Edelmann

Overview

Talks

Thermonuclear electron-capture supernovae - Motivating a long-overdue update to the supernova modeling pipeline for the exascale computing age

The thermonuclear supernova modeling pipeline has been refined for over four decades and has achieved substantial success in modeling various supernova subtypes. Nonetheless, continuous innovation is essential for maintaining supernova modeling at the forefront of computational astrophysics. In this work, we examine a novel scenario, so called thermonuclear electron-capture supernovae. Originally proposed by Jones et al. (2016), this scenario consists of a collapsing sAGB star that only narrowly escape collapse to a neutron star by runaway thermonuclear thermonuclear burning. Here, we explore the specific circumstances under which such a thermonuclear explosion can occur and under which conditions the collapse can be averted by nuclear burning. Subsequently, we leverage this scenario to motivate a long-overdue update to the thermonuclear supernova modeling pipeline, both by increasing the complexity of the physics included, as well as updating the underlying codebase for the latest exascale computing clusters. In particular, we advocate the integration of radiation hydrodynamics and the transition towards a performance portable programming model.

• Undergraduate at Ulm University
• Master Studies at the Technical University of Munich and the Max Planck Institute for Astrophysics (Thesis: Determination of the Expansion Rate of the Universe by Means of Type II‑P Supernovae)
• PhD at the Heidelberg Institute for Theoretical Studies/ Heidelberg University on numerical simulations of thermonuclear supernovae (Working project title: Thermonuclear electron-capture supernovae - thermonuclear explosion or gravitational collapse?)
• Fellow at the International Max Planck Research School Heidelberg

RISC-V HPC Terrain Familiarization

The number of RISC-V commercial products increased substantially this past year. This presentation is an orientation to the range of RISC-V hardware, HPC software support, the community, and the current state of HPC-relevant ISA extensions. Acquiring RISC-V hardware is no longer a question of when - it is possible now.

Chris is a senior principle research engineer at Tactical Computing Labs. His work experience includes compilers, runtime systems, systems level software, numerical libraries, applied math problems, and hardware simulation. He has a Masters Degree in Computer Science from Georgia Tech and an undergraduate degree in Computer Science from Clemson.

Asynchronous-Many-Task Systems: Challenges and Opportunities - Scaling an AMR Astrophysics Code on Exascale machines using Kokkos and HPX

Dynamic and adaptive mesh refinement is pivotal in high-resolution, multi-physics simulations, necessitating precise physics resolution in localized areas across expansive domains. Today's supercomputers' extreme heterogeneity and large number of compute nodes present a significant challenge for such dynamically adaptive codes, highlighting the importance of both scalability and performance portability. Our research focuses on how to address this by integrating the asynchronous, many-task runtime system HPX with the performance-portability framework Kokkos and SIMD types. To demonstrate and benchmark our solutions at scale, we incorporated them into Octo-Tiger, an adaptive, massively parallel application for the simulation of binary star systems and their outcomes. Thanks to this, Octo-Tiger now supports a diverse set of processors, accelerators, as well as network backends and can scale on various supercomputers, such as Perlmutter, Frontier, and Fugaku. In this talk, we outline our various integrations between HPX and Kokkos. Furthermore, we show the challenges we encountered when using these frameworks together in Octo-Tiger and how we addressed them, ultimately achieving scalability on a selection of current supercomputers.

Gregor Daiß is a PhD student at the University of Stuttgart, specializing in high-performance computing. His main interests include task-based runtime systems, distributed computing, performance-portability as well as refactoring large-scale simulations and porting them to accelerators. Current work mostly involves both Kokkos (for performance-portability) and HPX (task-based runtime system) for these purposes.

Journal of Open Source Software: bot-assisted open peer review and publication

The Journal of Open Source Software (JOSS) is an open-access, no-fee scholarly journal that publishes quality open-source research software based on open peer review. JOSS was founded in 2016 with the dual objectives of giving traditional academic publication credit for software work and improving the quality of research software. Since its founding, JOSS has published over 2500 software papers—and counting!—with over 80 active editors spread across seven topic-area tracks. To handle this level of submissions and publishing, relying on a fully volunteer team, JOSS relies on GitHub and a system of open tools for reviewing and publishing submissions, driven by chatbot commands. Authors submit short Markdown papers along with links to their software's repository, which are compiled to PDF via Pandoc. JOSS’s editorial bot performs automated health checks on submissions, and reviews take place in GitHub issues, with authors, editors, and reviewers issuing bot commands via comments. This talk will describe the publication experience of JOSS and its machinery, and how it can be adapted by other communities.

Kyle E. Niemeyer is an Associate Professor at Oregon State University in the School of Mechanical, Industrial, and Manufacturing Engineering. He also serves as the Associate School Head for Undergraduate Programs. He leads the Niemeyer Research Group, which uses computational modeling to study various phenomena involving fluid flows, including combustion and chemical kinetics, and related topics like numerical methods and parallel computing. He is also a strong advocate of open access, open source software, and open science in general, and has contributed in the area of standardizing research software citation. Kyle has received multiple prestigious fellowships throughout his career, including the AAAS Science & Technology Policy Fellowship in 2022, the Better Scientific Software (BSSw) Fellowship in 2019, the NSF Graduate Research Fellowship in 2010, and the National Defense Science and Engineering Graduate Fellowship in 2009. Kyle received his Ph.D. in Mechanical Engineering from Case Western Reserve University in 2013. He received BS and MS degrees in Aerospace Engineering from Case Western Reserve University in 2009 and 2010, respectively.

• Slides

Improving MPI Interoperability for Modern Languages and Systems

The Message Passing Interface standard has long been the lingua franca of HPC. Its design has enabled the development of many distributed parallel applications. After 30 years, the field of high-performance computing has seen several programming paradigms come and go. However, MPI has yet to address the challenges of accelerator-based computing, the advent of modern languages such as Rust, Python, and C++, and fully asynchronous programming models. This talk will provide insights into current efforts on modernizing MPI, from accelerator integration to improved datatype handling for modern languages.

Joseph Schuchart is a Senior Research Scientist at the Institute for Advanced Computational Sciences at Stony Brook University. His research revolves around distributed asynchronous and task-based programming models, communication libraries, and design aspects of integrating different models. Joseph received his M.Sc. in Computer Science from Dresden University of Technology in 2012 and his PhD from the University of Stuttgart in 2020. He is an active member of the MPI Forum and a contributor to the Open MPI project.