Korean yen
The Korean yen was the currency of Korea between 1910 and 1945. It was equivalent to the Japanese yen and consisted of Japanese currency and banknotes issued specifically for Korea. The yen was subdivided into 100 sen. It replaced the Korean won at par and was replaced by the South Korean won and the North Korean won at par.
Juche
In 1956, Kim Il-sung declared "Juche" to be the guiding principle of the economy. After the devastation of the Korean War, North Korea began to rebuild its economy with a base in heavy industry, with the aim of becoming as self-sufficient as possible. As a result, North Korea developed what has been called the "most autarkic industrial economy in the world". North Korea received a lot of economic aid and technical assistance from the Soviet Union and China, but it did not join Comecon, the Communist common market. In the 1990s, it had one of the world's lowest rates for dependence on petroleum, using hydroelectric power and coal instead of imported oil. Its textile industry uses vinylon, known as the ""Juche" fiber", which was invented by a Korean and which is made from locally available coal and limestone. The history of the development of vinylon often featured in propaganda that preached the virtues of technological self-reliance. North Korea had 10,000 CNC machines in 2010. The first domestic homemade CNC machine was introduced in 1995 and in 2017 it has around 15,000 machines.