Unless you are willing to take the KTX from Seoul into Busan, then connections from ICN-PUS are limited. Also, OZ doesnt operate GMP-PUS anymore, its operated by Air Busan, so you can't get reward seats on them using *A miles.

You can also fly directly into PUS from NRT/KIX/PVG/PEK or a couple of others using miles
http://en.wikipedia.org/wiki/PUS_(ai...d_destinations