The GIST Department of Electrical Engineering and Computer Science (EECS) has long been a powerhouse for nurturing talent across various high-tech industries. Today, we sit down with Alumnus Gil-Ju Lee, who earned his Ph.D. at GIST and is now shaping the next generation of engineers as an Associate Professor at Pusan National University.

Q. It is a pleasure to meet you. Could you please introduce yourself and share what you are currently working on?

Hello, I am Gil-Ju Lee. I joined the GIST EECS integrated MS/Ph.D. program in September 2016 and received my doctorate in February 2021. After completing a six-month postdoctoral fellowship at GIST, I moved to Pusan National University’s Department of Electrical Engineering and Computer Science, where I currently serve as an Associate Professor, balancing both research and education.

Q. What were the primary focuses of your research during your doctoral studies?

In Professor Young-Min Song’s lab, I conducted various applied research projects based on optics. My work revolved around two main pillars:

Passive Radiative Cooling: This involves researching eco-friendly cooling materials that dissipate heat using the principles of electromagnetic radiative heat exchange without consuming energy.
Bio-inspired Imaging Systems: I studied the structures of animal eyes—specifically "coplanar retinas"—which differ from the flat image sensors used by humans. This research led to the development of more effective curved lens sensors and camera systems.

Q. What was the most memorable or rewarding moment during your research career?

The greatest sense of accomplishment came whenever my hypotheses were proven through countless trials and eventually culminated in a published paper.

A particularly cherished memory is the evolution of my relationship with my advisor. At a certain point, he stopped being just a teacher and began treating me as a peer researcher, engaging in deep, intellectual discussions. Furthermore, out of the 16 papers where I served as the first author, the one that was the hardest to publish stands out. Although it was unfortunately rejected by Science before being published in a sister journal—and despite my advisor’s initial skepticism about the topic—sticking to my ideas and proving them right was immensely rewarding.

Q. How did you manage the stress of graduate school life?

The answer is simple: "Exercise, no matter what." During my Ph.D. years, I was so immersed in research that I often left the lab at 3:00 AM and returned by 8:00 AM. When I felt my health declining, I started weight training. Lifting heavy weights cleared my mind and washed away my anxieties about research. Paradoxically, emptying my head in the gym often led to my best research breakthroughs.

Q. Why did you choose GIST among so many other options for graduate school?

To be honest, there wasn't a grand reason initially (laughs). I was an undergraduate researcher under my advisor at Pusan National University, so when he was appointed to GIST, I naturally followed him.

However, a tip I want to give prospective students is to consider whether you can become a "key player" who leads the core research in a lab. I found that opportunity at GIST and have no regrets.

Q. How would you describe the research environment at GIST?

GIST’s research infrastructure is world-class, rivaling that of prestigious international universities. While the surrounding area felt a bit quiet back then, that lack of distraction actually created the perfect environment to focus entirely on my work.

Q. What are your future goals, and do you have a message for your juniors?

In the past, my goal was simply to be a "good researcher." Now, it is to be an "educator who raises good researchers." I want to nurture talent that doesn't just excel in lectures but truly understands the value of research and possesses the grit to solve problems.

To my juniors: regardless of the path you choose, AI technology will be essential. However, you cannot survive this era through rote memorization for exams alone. The "problem-solving ability" gained through deep contemplation and repeated failures in graduate school is the true competitive edge required in the AI era. I hope you fully realize your potential here at GIST.