Yumin Zhang is an associate professor in the Department of Physics and Engineering Physics, Southeast Missouri State University, USA. His academic career started in China; in 1989 he obtained a master's degree in physics from Zhejiang University and then was employed as technical staff in the Institute of Semiconductors, Chinese Academy of Sciences. After receiving a PhD degree in electrical engineering from the University of Minnesota in 2000, he started to work as a faculty member at the University of Wisconsin-Platteville and then at Oklahoma State University-Stillwater. His research fields include semiconductor devices and electronic circuits. Since joining Southeast Missouri State University in 2007, he has also investigated in the field of Physics and Engineering Education. In addition, he is very interested in teaching Chinese to non-native speakers and has written a book on this topic: Roots and Branches: a Systematic Way of Learning Chinese Characters.