Yu Hyeongwon

Yu Hyeongwon (1622–1673), also spelled as Yoo Hyung-Won, was a politician and Neo-Confucianism scholar and science scholar of the Korean Joseon Dynasty. He was Korean pioneer of the early silhak ("practical learning") school as well as an avid social critic and scholar of the late Joseon period. He was the disciple of Misu Heo Mok and second cousin of the silhak scholar Seongho Yi Ik.
Yu hailed from the Munhwa Yu clan, and many of his extended family members held high official positions in the Joseon government.
References.
Kang, Jae-eun; Lee, Suzanne. (2006) "The land of scholars: two thousand years of Korean Confucianism", Homa & Sekey Books, 