University of California, Santa Barbara

Professor Linda Petzold wins 2011 Faculty Research Lecture Award

The Faculty Research Lecturer is the highest honor that this university bestows on the faculty. As the chair of the Faculty Research Lecturer Award Committee, it is my great privilege and honor to announce that the winner of this year’s Faculty Research Lecturer is Professor Linda Petzold of the Department of Computer Science and the Department of Mechanical Engineering.

Professor Petzold received her Bachelor of Science in Math and Computer Science in 1974, and received her Ph.D in Computer Science with a Mathematics minor at the University of Illinois in 1978. She worked at Sandia National Laboratories and at Lawrence Livermore National Laboratory, and taught at the University of Minnesota before she came to UCSB as professor in Mechanical Engineering and Computer Science in 1997.

Professor Petzold has a superb record of research that has been well-recognized for its creativity and impact. She was elected to the National Academy of Engineering in 2004 “for advances in the numerical solution of differential-algebraic equations and their incorporation into widely distributed software.” She is a Fellow of the American Association for the Advancement of Science (AAAS), the Society for Industrial and Applied Mathematics (SIAM), and the American Society of Mechanical Engineers (ASME). She has received numerous prizes. She has authored approximately 180 journal and conference publications and 2 widely-cited books, and has produced 2 major software packages. Professor J. Tinsley Oden of the University of Texas states: “I can truly say that Linda Petzold is one of the most highly regarded and highly recognized computational scientists and computer scientists in the world.” Professor J. C. Butcher of the University of Auckland, New Zealand, also writes: “Her name is a household name amongst numerical analysts throughout the world.”

Professor Petzold’s high level visibility and impact began with her seminal article, “DAEs are not ODEs” which she published in 1981. Many physical systems are naturally described as systems of DAEs—differential-algebraic equations. These systems often consist of differential equations coupled to nonlinear constraints. DAE systems occur in the modeling of electrical networks and power systems, flow of incompressible fluids, mechanical systems simulation and control, chemical process simulation and control, and in many other applications. These problems include systems that are, in many ways, quite different from ordinary differential equations (ODEs).

In her article, Professor Petzold showed that for a large class of problems there were serious difficulties with this approach and outlined some future research areas. This article was ahead of its time, but set out the agenda for this subject in a prophetic way. Since the publication of this article, Professor Petzold, played a leading role in the explosive growth of the new field of DAEs. Thus before she reached the age of 30, she had established a new field and guided the field to its maturation. This led to her major role in the development of DASSL, a software package for which she won the Wilkinson Prize for Numerical Software in 1991. This numerical solver for DAEs, and its successor, DASPK, have been widely distributed and used successfully for solving a large number of problems in science and engineering.

During the past decade, Professor Petzold undertook a new major research direction: computational systems biology, and again established an emerging discipline in its own right. In microscopic systems formed by living cells, small numbers of reactant molecules can result in dynamical behavior that is discreet and stochastic rather than continuous and deterministic. In simulating and analyzing such behavior it is essential to employ methods that directly take into account the underlying discrete stochastic nature of the molecular events. This leads to an accurate description of the system that in many important cases is impossible to obtain through deterministic continuous modeling such as ODEs.

Before Professor Petzold became involved in this area of research, there had existed Gillespie’s Stochastic Simulation Algorithms (SSA) to treat these problems, but as a procedure, it was prohibitively inefficient for most realistic problems. Professor Petzold and her group, working closely with Gillespie, succeeded in developing a multiscale computational framework for numerical simulation of chemically reacting systems, where each reaction will be treated at the appropriate scale. Professor Petzold and Dr. Gillespie have co-authored several landmark papers on multiscale simulation for discrete stochastic systems. Professor Petzold’s research group developed the StochKit package for multiscale discrete stochastic simulations.

From this, Professor Petzold then moved into a third important field. She is currently actively involved in collaborative efforts in systems biology to obtain a better understanding of the biochemical processes including the gene regulatory network underlying Circadian Rhythms in neurons, Cell Polarization in Yeast Mating, Unfolded Protein Response in yeast, Post Traumatic Stress Disorder, Coagulopathy, and Diabetes Type 2. As you can see from this list, the practical application of her research is enormous.

Professor Petzold has served on numerous boards and panels of the National Science Foundation, the Department of Energy, and other federal agencies. She was Editor-in-Chief of SIAM Journal of Scientific Computing, served on the SIAM Council, and has been active in the organization and promotion of the Society of Industrial and Applied Mathematics, as well as the American Association for Mechanical Engineers. She gave numerous lectures, the list of which fills 16 pages (single-spaced) of her CV.

Throughout her career, she has closely interacted with physical scientists and engineers. This has enabled her to identify strategic next-generation problems for which solution are urgently sought. These include a wide variety of applications in biology, nanotechnology, materials, mechanical engineering, computational chemistry and chemical engineering. Summing up Professor Petzold’s achievements in research, Professor Richard Alkire of the University of Illinois writes: “There are few people in the world that can compare with Petzold’s unique ability to formulate software advances that contribute so clearly to a broad menu of science and engineering problems…. While some colleagues in her field took over well-established programs of long-standing, Petzold has by contrast forged a pioneering position that is hers alone.”

Professor Petzold is also very active in education and outreach. She directs the UCSB Institute for Biotechnologies SABRE summer research internship program for students from Historically Black Colleges and Universities and Minority Institutions, and serves on the Chancellor’s Outreach Advisory Board. She is also a highly-visible role model for women students in the scientific community, and is often called upon to speak to groups of women and minority students who may be interested in pursuing a career in engineering or science. But, as one letter writer states, “she is more than that. She is a role model for anyone with similar aspirations.”

Professor Petzold is also an outstanding colleague and has worked tirelessly on behalf of both the scientific community and UCSB. She served as the Chair of the Department of Computer Science from 2003-2007. She established and now chairs the Graduate Emphasis in Computational Science and Engineering across 7 departments in both science and engineering.

It is thus with a great sense of honor and pleasure that I announce that the highest honor that UCSB bestows on its faculty—the Faculty Research Lecturer—is awarded to Professor Linda Petzold.

Faculty Research Lecturer Award Committee
• Tsuyoshi Hasegawa, Chair
• David Awschalom
• Howard Giles
• William Murdoch

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