PHILADELPHIA Computer scientists at the University of Pennsylvania have received a $2,184,300 grant to boost the reliability of the specialized miniature computers found in electronic devices all around us. The award, from the federal government Defense Advanced Research Projects Administration (DARPA), will support the researcherswork over the next three years.

"These embedded computers are everywhere, from toasters to cellular phones to airplanes," says lead investigator Insup Lee, Ph.D., Penn professor of computer and information science. "There are many more of them than there are of us, and they are growing in number and complexity all the time."

Since tiny embedded computers can literally make the difference between life and death, their reliability is crucial. They underpin most of the modern medical devices that hospital patients depend on equipment like heart-lung machines, defibrillators, dialysis machines and imaging devices from mammography machines to MRIs.

New automobiles can house a dozen small computers, each regulating key functions such as antilock braking systems and engine performance. Air traffic control systems and the machinery that monitors nuclear reactors are rife with the specialized processors. Indeed, much of last year concern about the "Y2K bug" was grounded in uncertainty over what might happen to the computers found not on our desktops but in the many electronic devices that surround us.

"As embedded computers grow more complex and powerful, the number of bugs that might affect them also grows," Dr. Lee says. "Moreover, with embedded systems becoming increasingly networked, the failure of one can cause many others to fall like dominoes."

The work of embedded computers is complicated because most operate very rapidly in response to continuously changing input. Computer scientists have traditionally worked with discrete changes, while continuous changes have been within the scope of control theory. Featuring discrete control and working in a continuously changing environment, embedded computers lie on the boundary between the two disciplines.

Dr. Lee and other Penn researchers will build upon recent results from computer science and control theory to develop new models to better predict how embedded processors might respond under such multifaceted circumstances.

Dr. Lee colleagues on the DARPA grant include Rajeev Alur, Ph.D., associate professor of computer and information science; Vijay Kumar, Ph.D., professor of mechanical engineering and applied mechanics and deputy dean of Penn School of Engineering and Applied Science; George Pappas, Ph.D., assistant professor of electrical engineering; and Oleg Sokolsky, Ph.D., research associate in computer and information science.