September 19, 2006
'Out of the blue,' a MacArthur award for aeronautics scholar Claire Tomlin
By Dawn Levy
Airplanes and genes may not seem to have much in common, but Claire Tomlin, today named a MacArthur Fellow, knows better.
Effective air-traffic control can mean the difference between a safe landing and a disaster. And good control of geneswhich turn on, ramp up, ramp down and turn off in complex feedback loops to produce proteinscan make the difference between health and disease. Whether a complex system is operating in the wild blue yonder or in the human body, control matters.
Tomlin, an associate professor of aeronautics and astronautics and, by courtesy, of electrical engineering, studies control theory and practice. A phone call on Sept. 12 told her she'd won a MacArthur Fellowship, frequently called the "genius grant," a "no strings attached" award of $500,000 that supports people, not projects. It goes to talented individuals who "have shown extraordinary originality and dedication in their creative pursuits and a marked capacity for self-direction," according to the MacArthur Foundation website. Stanford's current community includes 24 MacArthur Fellows, including Tomlin, age 37.
"Do you know someone who's been a MacArthur Fellow?" MacArthur Fellows Program Director Daniel Socolow asked Tomlin over the phone. Tomlin named Daphne Koller, professor of computer science at Stanford, and Naomi Leonard, a professor of mechanical and aerospace engineering at Princeton University.
"Well, now there's a MacArthur Fellow you know even better," Socolow said, informing her she'd been selected.
"I couldn't talk," Tomlin, all smiles, said during an interview Friday in her office in the basement of the Durand Building. "I was just so surprised. It came out of the blue."
Socolow said Tomlin could tell just one person about the award that day. Over lunch she told her husband, Shankar Sastry, a professor of electrical engineering and computer science at the University of California-Berkeley and director of the Center for Information Technology Research in the Interest of Society, a collaboration of four UC campuses. The couple spends Monday through Thursday at their home in Berkeley, then Friday through Sunday at their home in Palo Alto.
This year, Tomlin, the author of about 120 technical articles, is on leave from Stanford. Nonetheless, she spends 20 percent of her time here, advising five doctoral students and conducting research as the sole female faculty member of the Aero/Astro Department. The remaining time she spends at UC-Berkeley, where she also has a faculty appointment and advises two doctoral students.
For a joint project with NASA Ames Research Center, she is working to automate air traffic control and design flight-management systems that integrate collision avoidance. Also working on the design and control of a team of unmanned aerial vehicles, she focuses on formation flying, distributed control and reliable control over communication links.
Tomlin became motivated to study systems control as an undergraduate at the University of Waterloo in Ontario, Canada, where she received her bachelor's degree in electrical engineering in 1992. "I was looking for ways to use math to tackle practical problems," she said. She earned her master's degree in electrical engineering from Imperial College, London, in 1993, and her doctorate in electrical engineering and computer science from UC-Berkeley in 1998. It was during her graduate studies at Berkeley when NASA, a research entity behind the Federal Aviation Administration, began directing more funding to modernizing air traffic control.
"It's a wonderful control problem," said Tomlin, who has taken some flying lessons at Palo Alto Airport. "There are huge bottlenecks. There are problems with bad weather and equipment issues. There was a push toward thinking about what kinds of analyses and computer tools we could employ to solve these problems, how we could automate some of what air traffic controllers do manually."
Air traffic control is complex at its three basic levelsover big regions (e.g., all of California and the Pacific Ocean), over local areas (e.g., the 50-mile radius that includes airports at San Francisco, Oakland and San Jose) and around a specific tower, such as the one at San Francisco International Airport that in busy times may orchestrate one landing per minute, Tomlin said.
Control systems have to take into account a combination of constant and changing conditions, she said. Constant modes like "auto pilot" set planes cruising at steady headings and speeds. Changing modes may accelerate or reroute planes. Tomlin works to create hybrid systems that can control both constant and changing aspects of air traffic.
Expanding her scope from controlling flight to controlling genetics was not a long journey for Tomlin, whose research has been funded by the Office of Naval Research, the Air Force Office of Science Research, NASA, the Defense Advanced Research Projects Agency, the National Institutes of Health and Stanford's Bio-X Program.
She recently co-authored a paper in the journal Science about how genes orchestrate the development of fruit fly wings with Jeffrey Axelrod, associate professor of pathology. Genes produce proteins, and many networks of genes get activated and deactivated during regulation of biological systems. Tomlin compared Axelrod's real-world data with predictions from simulations using mathematical models. About the same protein concentrations were produced in experiments as in simulations. "That meant the model was plausible," she said.
Understanding how a fly wing forms along an axis of development may help scientists better understand anomalies that arise during development, such as spina bifida, a neural tube birth defect, and Usher syndrome, a cause of congenital deafness in which hair cells in the cochlea point in random directions.
"More and more I'm working with biologists," she said. "I know the systems I've worked on, but I'm building on sand."
Stanford's newest genius said that means it's time to hit the books and laboratories. With a sabbatical coming up, Tomlin said she'd use some MacArthur money to beef up her biology background by taking classes and doing experiments.
A photo of Tomlin is available on the web at http://newsphotos.stanford.edu/.