As director of UMD’s applied mathematics & statistics, and scientific computation graduate program, Radu Balan oversees many branches of math—and much more.

Radu Balan doesn’t consider himself a mathematician, which might sound surprising coming from a University of Maryland Professor of Mathematics.
“I’m an engineer at my core,” Balan said. “In fact, my background is engineering first, then physics.”
With a Ph.D. in applied and computational mathematics to boot, Balan’s interdisciplinary background serves him well in a leadership role he assumed in July 2024: director of UMD’s applied mathematics & statistics, and scientific computation (AMSC) graduate program. 

“Our 150-plus affiliated faculty come from the entire campus and all sorts of research areas, which is one of our selling points,” Balan said. “We like to say that AMSC is a structured program with flexibility.”

The flexibility to pursue different academic disciplines has always been important to Balan, who wasn’t exposed to applied mathematics until later in life.

Finding mathematical harmony

Balan grew up in Romania, a country with a strong mathematical tradition, but initially took an interest in other subjects. He earned a bachelor’s degree in electrical engineering from the Polytechnic Institute of Bucharest in 1992, followed by a bachelor’s in physics from the University of Bucharest in 1994. At some point along the way, he also discovered applied math.

Inspired by the prospect of applying math to fields he already enjoyed, Balan enrolled in Princeton University’s applied and computational mathematics Ph.D. program. His advisor, Ingrid Daubechies, has been dubbed the “godmother of the digital image” for her pioneering work on wavelets that led to image-compression technologies like JPEG 2000, an improvement to the original JPEG image file format.

Daubechies introduced Balan to the field he currently specializes in: harmonic analysis, which breaks functions down to the sum of their parts, such as waves and signals, and has broad applications in medical imaging, audio processing, machine learning and more. Above all else, Daubechies gave Balan an entirely new perspective on mathematics.

“Ingrid shaped not only my career but my vision of applied math,” Balan said. “I learned to have an open mind in math and not live in an ivory tower and say, ‘This is the truth, and therefore this is the only problem I need to work on.’”

After graduating in 1998, Balan was eager to put everything he had learned into practice and accepted a position as a research scientist at Siemens, where he studied signal processing and communications for eight years.

Though Balan enjoyed his time there, his goal was to work in academia. The opportunity arose in 2007 when he accepted a position as an associate professor at UMD. Balan said he was attracted to UMD’s Department of Mathematics for its active research, including advancements in harmonic analysis. 

Balan now serves as co-director of the Norbert Wiener Center for Harmonic Analysis and Applications and is an affiliate with the Artificial Intelligence Interdisciplinary Institute at Maryland. 

Papers and patents

During his career, Balan has published nearly 50 papers in academic journals, including a mix of mathematical theory and applications.

Balan is best known for his work on phase retrieval, which uses algorithms to reconstruct lost information about the timing and position of an electromagnetic wave, sound wave or other signal. While at Siemens, Balan’s 2005 signal reconstruction research led to the invention of a device to help solve what’s known as the “cocktail party problem.”

“At a cocktail party, you're in a room full of people talking more or less simultaneously, so we created a device with microphones to pick up what individual speakers are saying,” Balan explained. “It reduces interference and helps you focus on one speaker at a time.”

Balan has contributed to more than 20 patented inventions—mostly at Siemens, but one while working at UMD in 2017. The latter was a device that used a microphone network to improve the monitoring of industrial equipment.

“You have these sensors—microphones mostly—to monitor each active component for abnormalities or something breaking down,” Balan explained.

Aside from his research, Balan is also one of three editors-in-chief for the Applied and Computational Harmonic Analysis journal and serves on the editorial board of the American Institute of Mathematical Sciences, which oversees several journals.

Balan also monitors the current state of applied math and the job market to ensure AMSC students gain the most valuable skills for applied mathematicians.
“What I enjoy most about my job is discovering new problems,” he said, “but more importantly, new solutions.”

Written by Emily Nunez