Complex sentence: Choy was a professor in the department of chemistry at Seoul National University (1981-2004), and is currently a distinguished professor and director of the Center for Intelligent Nano-Bio Materials (CINBM) at Ewha Womans University.
Split into simpler sentences: Choy was a professor in the department of chemistry at Seoul National University (1981-2004). He is currently a distinguished professor and director of the Center for Intelligent Nano-Bio Materials (CINBM) at Ewha Womans University.