Expert in Embedded Systems Joins Faculty

After numerous trips between Eaton and Nichols Halls during his first week on campus, Heechul Yun is wondering if his newly purchased bicycle is the best way to get around KU. The new assistant professor of electrical engineering and computer science (EECS) never imagined there would be so many hills in flat-as-a-pancake Kansas.

Navigating uneven terrain may be a theme this year for the first-time professor as he juggles teaching, research, advising, and other responsibilities. He sees his different roles as opportunities to capture students’ interest in topics that fascinate him, share his experience in industry and research, and delve into research on making more predictable and efficient software infrastructure.

“Embedded systems are everywhere: from everyday smartphones and tablets, to cars and airplanes, to factory automation systems and power plant control systems. They are providing vital infrastructure for our society,” said Dr. Yun, who received his Ph.D. in computer science this summer from the University of Illinois at Urbana-Champaign.

The software and hardware of today’s embedded systems are much more complex. To illustrate his point, Dr. Yun compares a military jet built in the 1960’s that used 50 thousand lines of code to the new F-35 Joint Strike Fighter with 9.5 million lines of code, which is running on top of numerous complex microprocessors.

“My research is to build a software foundation that will make these systems more predictable, reliable, and efficient. For example, one of my current research focus areas is to improve real-time performance of the Linux operating system, which powers millions of embedded systems. Successful research, therefore, could make huge real-world impacts,” said Dr. Yun.

Dr. Yun says it is critical to improve the real-time performance of complex software running on embedded microprocessors ―especially multi-core processors. He is developing system-level techniques to minimize interference and ensure predictability of multi-core based embedded systems.

“While many industries already have moved toward multicore-based computers, critical embedded systems, such as those in the F-35 built by Lockheed Martin, a sponsor of my research, are just beginning to incorporate multi-core computers. The industry is actively seeking solutions to make multi-core computers more predictable and ultimately certifiable for commercial use in products,” said Dr. Yun.

His second research area is in energy-efficient computing. He points to the short battery life of smartphones and the huge power cost associated with cloud computing systems. He will save power by identifying and controlling components that do not need to run at maximum levels. For example, when a CPU-intensive workload is running on a computer, the machine can reduce the speed of its main memory, hence saving power without affecting performance.

Improving reliability is Dr. Yun’s final research area. With millions of lines of code, it is almost impossible to find subtle bugs in complex software systems. No matter how diligent developers are, bugs will make it into software, especially those that manifest only in rare unintended program states, said Dr. Yun. Instead of fixing them, he seeks to prevent software from entering these buggy states.

After receiving his bachelor’s and master’s degrees in computer science from Korea Advanced Institute of Science & Technology, he spent five years as a system software engineer at Samsung Electronics. His desire to conduct greater in-depth research on bigger challenges led him to pursue his Ph.D. at the University of Illinois at Urbana-Champaign. His doctoral research focused on operating system level resource management for real-time systems, with a focus on performance isolation and energy saving.  His doctoral research was supported in part by leading avionics companies Lockheed Martin and Rockwell Collins.