The calculated distance (air line) between Imsil and Uijeongbu-si is approximately 148 miles respectively 238 kilometers.
By car or train, the actual journey to Uijeongbu-si is certainly longer, as only the direct route (as the crow flies) between Imsil and Uijeongbu-si has been calculated here.
Air line (approximately)
238 kilometers
128 nautical miles