As a long-time amateur radio-enthusiast listening to Chinese, North Korean and Soviet radio broadcasts from his location in Australia, Mark Freeman was intrigued by how these countries eventually opened up and changed over the decades – with the exception of North Korea.

Finding out why became one of his chief motivations when, four years ago, he began spending most of his free time researching and traveling to North Korea to gather materials and information. He presented the results of his findings at a broadcasting conference in Pennsylvania on Thursday.