I'm pretty sure that KE's award redemption chart is for those using KE mileage. Check DL's website. Click SkyMiles, then click program info, click redemption opportunity, click Korean Air Awards. The KE partner awards state 50K (Award code K740)round-trip from the U.S. to Southeast Asia, but says that "only residents of Hawaii may use Honolulu as a gateway for Honolulu-Seoul flights." If this applies to you, request expedited delivery of your certificate. Call KE for upgrade availability. Surrender the certificate at a CTO or at check-in. In my experience, they will make xerox copies of the certificate and attach them to your ticket!

The minimum upgradeable fare on KE is "H." If "N" is higher than "H" you're in luck. I find that the load factors on KE in business aren't that high due to bad publicity concerning safety as well as an economy only recently coming out of a massive recession.

Hope this helps.