Stability robustness of LQ optimal regulators for the performance index with cross-product terms. - Dohyoung Chung; Taesam Kang; Jang Gyu Lee (IEEE Trans. Autom. Control., 1994)

Robustness of controllability and observability of continuous linear time-varying systems with parameter perturbations. - Dohyoung Chung; Chan Gook Park; Jang Gyu Lee (IEEE Trans. Autom. Control., 1999)

The robustness of controllability and observability for discrete linear time-varying systems with norm-bounded uncertainty. - Jaewon Seo; Dohyoung Chung; Chan Gook Park; Jang Gyu Lee (IEEE Trans. Autom. Control., 2005)