Congratulations to Linda Petzold, professor in the Computer Science and Mechanical Engineering Departments in the UC Santa Barbara College of Engineering, who in November received the 2018 IEEE Computer Society Sidney Fernbach Award.

Established in 1992 in memory of high-performance computing pioneer Sidney Fernbach, this award is one of the IEEE Computer Society’s most prestigious, recognizing outstanding contributions in using innovative approaches in the application of high-performance computers. The IEEE cited Petzold for her “pioneering contributions to numerical methods and software for differential-algebraic systems and for discrete stochastic simulation.”

Petzold’s recent research has focused on modeling, simulation, and analysis of multiscale systems in materials, biology, and medicine. She is best known for her pioneering work on the numerical solution of differential algebraic equations (DAEs). DAEs arise in the simulation of physical systems that involve nonlinear constraints, such as mechanical systems, electrical networks, power systems, the flow of incompressible fluids, and many others.  

Differential equations, which mathematically describe movement and interaction, are often applied to aggregates of things. “A baseball moving through space, for instance, is made up of huge numbers of molecules that, together, exhibit coherent movement. Newton’s laws of motion, which comprise differential equations, very accurately describe that,” Petzold explains. “But at smaller scales, like the scale of cells in biology, there are far fewer molecules, and some of them are present in very small quantities. Sometimes, these molecules are involved in making key decisions, so where they are and what they’re doing can have a big impact. To capture some cellular processes, it is necessary to simulate them on a much finer, molecule-by-molecule, scale, than is possible with differential equations. “

Petzold’s impact has been enhanced by the fact that she develops not only theory for the numerical solution of differential-algebraic equations and for discrete stochastic simulation, but also the software tools that enable its use in computer simulation. She created the DASSL software, which stands for “Differential Algebraic System Solver Sandia Livermore,” at Sandia National Labs shortly after earning her PhD. She also developed its successor, DASPK, for the numerical solution of large-scale DAE systems. Both software systems are widely used throughout science, engineering, and technology. She and her UCSB PhD students and postdocs in the Computational Science and Engineering Research Group developed, in collaboration with Professor Chandra Krintz of the Computer Science Department, a cloud-based development environment called StochSS (Stochastic Simulation Service), for modeling and simulating biological processes.

Being recognized both for her theoretical work and software development, she says, is what makes the Fernbach Award so special. “This award is from the computational-science community. It’s my home community, the area in which my PhD work was done,” she says. “And it recognizes my passion for developing infrastructure [software].”

In university settings, she explains, researchers tend be incentivized more strongly to write papers than to take an idea from concept to impact. Papers are usually recognized more than software, whereas the software, which is based on the computational mathematics introduced in the papers, usually has more impact. “Software contributions are not always recognized, although they require a tremendous amount of both work and expertise. I appreciate that this award recognizes both my computational-mathematics research and the software based on that research which enables it to have an impact in science and engineering.” 

Petzold is currently the Mehrabian Distinguished Professor in the Departments of Mechanical Engineering and Computer Science, and director of the Computational Science and Engineering Graduate Emphasis at UC Santa Barbara. She is a member of the US National Academy of Engineering and a Fellow of the Association for Computing Machinery (ACM), the American Society of Mechanical Engineers (ASME), the Society for Industrial and Applied Mechanics (SIAM), and the American Association for the Advancement of Science (AAAS). 

Named the UCSB Faculty Research Lecturer for 2011, Petzold was awarded the SIAM/ACM Prize for Computational Science and Engineering in 2013, received an Honorary Doctorate from Uppsala University in 2015, and was awarded the SIAM Prize for Distinguished Service in 2016. 
The Sidney Fernbach award was presented to Petzold at the 2018 International Conference for High Performance Computing, Networking, Storage, and Analysis (SC18) Conference in Dallas, Texas, on November 13, 2018.