The executive and legislative branches operate primarily at the national level, although various ministries in the executive branch also carry out local functions. Local governments are semi-autonomous, and contain executive and legislative bodies of their own. The judicial branch operates at both the national and local levels.The South Korean government's structure is determined by the Constitution of the Republic of Korea. This document has been revised several times since its first promulgation in 1948 (for details, see History of South Korea). However, it has retained many broad characteristics; with the exception of the short-lived Second Republic of South Korea, the country has always had a presidential system with a relatively independent chief executive.