Class of 2025: Yihan Liu builds his future on mathematical theory

Name: Yihan Liu

Majors: Computational modeling and data analytics & mathematics

Hometown: China

Plans after graduation: Go to graduate school to pursue a Ph.D. in robotics (ECE) at Georgia Tech

Favorite professor/class: Dr. Lizette Zietsman/MATH 2405 & 2406

Yihan Liu — a native of China who spent his high school years in Northern Virginia — knew early on that attending Virginia Tech for his undergraduate degree with a full scholarship would be the right choice.

‘Build something tangible and then make it move’

At Virginia Tech, Liu has had the opportunity to develop his interests in control theory and applied mathematics. Specifically, control theory is a field at the intersection of applied mathematics and engineering that enables the precise control of engineered processes and machines.

Liu's interest in control theory and passion for mathematics were sparked by MATH 2405 and MATH 2406, where he particularly enjoyed studying differential equations and linear algebra. Recognizing Liu's enthusiasm, his professor, Lizette Zietsman, introduced him to control theory and advised him to pursue undergraduate research in the field.

Additionally, Liu discovered his passion for robotics throughout his undergraduate career, identifying it as his primary field of interest through interacting with Robotics Club and various course projects. He will be continuing this pursuit at Georgia Tech, where he will begin his Ph.D. in robotics.

“It’s quite interesting to build something tangible and then make it move,” said Liu.

The CMDA program’s integrated approach — combining computer science, mathematics, and statistics — has been beneficial to Liu in his study of robots.

“As robots take on increasingly complex tasks — such as legged locomotion, dexterous manipulation, or interaction in uncertain environments — data-driven methods and robot learning are advancing rapidly and represent the future of the field,” said Liu. “That’s why having a strong background in data science and statistical analysis is essential.”

Meanwhile, as part of his work in control theory, Liu has assisted Jeff Borggard, a professor in the Department of Mathematics, with building an inverted pendulum. The pendulum is being used to test a new control algorithm developed by Borggard and Zietsman.

“The inverted pendulum is a very classic and fundamental problem in control,” said Liu. “It's a good platform to test different control algorithms including both traditional model-based or data-driven control, so I built two – one for Dr. Borggard and one for myself.”

Liu also spent two summers at the University of Arizona through the National Science Foundation Research Experiences for Undergraduates (NSF REU) program. There he conducted data driven research into wind turbines, specifically running Markov Chain Monte Carlo (MCMC) simulations to analyze rare events in the operation of wind turbines. Through these experiences, Liu gained valuable skills in modeling real-world engineering systems and applying statistical methods for analysis.

The CMDA advantage

As one of the CMDA program’s Outstanding Seniors in the Class of 2025, Liu demonstrates that there is no such thing as a “typical” CMDA student — and that the program offers opportunities in a wide variety of domains.

“One of the CMDA classes that inspired me was 3606,” said Liu. “The class introduced many mathematical tools that are highly relevant to control, such as kinematic system modeling and numerical methods for solving linear systems. I found it very helpful and have been able to apply what I learned directly to my research projects.”

But what made the biggest impact on Liu during his time as a CMDA major was the flexibility within the program and its reasonable study plan.

“I have a lot of free space to pick classes from a very wide pool in my interests — I don’t see such flexibility in other majors,” said Liu.

Liu also extols the virtues of forming close relationships with his professors — those that can guide him into making the choices that are right for him and his interests.

“I talk a lot with them,” said Liu. “They offer great advice. When I’m facing a decision, I like to ask many people for their perspectives—through those conversations, I’m better able to figure out what I truly want to do.”