Did you know that over 80% of people worldwide have irregular sleep habits? These sleep issues don’t just leave us feeling tired — they affect our health, focus, and quality of life. Now, a new sleep algorithm developed by a team of Korean researchers is aiming to change that. And it’s available on Samsung Galaxy smartwatches around the world, including the newly launched Galaxy Watch8 series.
The personalized sleep guide, created by Professor Jae Kyoung Kim’s research team at KAIST and the Institute for Basic Science (IBS), doesn’t just tell you how long you slept. It actually recommends the best time for you to go to bed — helping you build healthy sleep habits and feel more refreshed every day.
What makes it special? Unlike most sleep features that focus only on the past (“You slept six hours last night”), this algorithm looks ahead. Using mathematical models and your body’s circadian rhythm, it suggests a personalized “sleep window” — like “Going to bed between 11:10 PM and 11:40 PM is ideal for you tonight.”
“It’s kind of like a weather forecast,” said Professor Kim. “Instead of just telling you what happened yesterday, it helps you prepare for tomorrow — so you can sleep better and feel better.”
The algorithm was developed over three years by a small team of mathematicians, not professional app developers. “We faced a lot of challenges trying to turn our research into a real product,” Kim admitted. “People kept asking us when they could try the algorithm, and we always felt bad that we couldn’t release it properly. Now, thanks to the support of KAIST’s Technology Commercialization Center and our partnership with Samsung, our work will finally reach people around the world.”
The academic world is paying attention, too. Professor Kim’s presentation on the algorithm was selected for the Hot Topics session at SLEEP 2025, the world’s largest sleep conference held in the U.S., and will also be featured at World Sleep 2025 in Singapore this fall.
Professor Kim is also working with Professor Eun Yeon Joo’s team at Samsung Medical Center to develop even more advanced sleep recommendation technology. Together, they created “SLEEPS,” an algorithm that predicts sleep disorders (available at sleep-math.com). Meanwhile, development continues on their own sleep app — with the hope of bringing math-powered sleep science into more people’s everyday lives.
Professor Kim is a world-renowned expert in mathematical biology. In 2025, he became the first Korean scientist to give a keynote speech at the SIAM Annual Meeting, and the first Korean to join the editorial board of SIAM Review, one of the most prestigious journals in applied mathematics. His work shows how basic science and mathematics can lead to real solutions that help people live healthier, better lives.