Yeon-Seok Choi

Young Hwa Con & Eng Co., Ltd. manufactures and installs steel structures for skyscrapers and plants in Korea. It also provides steel structures for Middle East oil refineries, gas processing and petrochemical plants. The company was founded in April 1988 and is headquartered in Seoul, South Korea.

Daesung Industrial Gases Co., Ltd. produces gases and related products. It supplies industrial gases, specialty gases for semiconductors, ultra high purity gases, standard gases, precise gas mixtures, medical gases and gas equipment. The firm also specializes in the on-site business that allows the installment of gas production facilities at the customer's site. It also provides pipe-line distribution system which consist of distributing gases more steadily, economically and quickly. The company was founded on February 19, 1979 and is headquartered at Seoul, South Korea.