Po-Jen Yang is a PhD student majoring in mechanical engineering at National Central University in Taoyuan, Taiwan. He has been a researcher on Associate Professor Jung-Chou Hung’s team since he began his pursuit of a master's degree. His research interests include precision electrochemical machining (ECM), polishing, deburring, precision electrical discharge machining (EDM), ultrasonic machining (USM), micromachining, and metal surface treatment.