The calculated distance (air line) between Chinju and Yangp'yŏng is approximately 162 miles respectively 261 kilometers.
By car or train, the actual journey to Yangp'yŏng is certainly longer, as only the direct route (as the crow flies) between Chinju and Yangp'yŏng has been calculated here.
Air line (approximately)
261 kilometers
141 nautical miles