We recommend 2 main ways from Incheon Int'l Airport to National institute for mathematical science (venue): by Airport Limousine bus and Express Train (KTX). The picture and explanation below will help your comfortable travel.
Way 1 Incheon Int'l Airport → Limousine Bus → Daejeon Government Complex
Take an Airport Limousine Bus from Incheon Int'l Airport to Daejeon.
You can buy the limousine bus tickets for Daejeon Government Complex at the Transportation Information Counters (near the exits 4, 6, 7, 8, 11, 13 on the 1st floor). With the bus ticket, you should go to 9D (The bus stop for Daejeon Government Complex) on the 1st floor to get on the bus. The bus runs every 20~40 minutes from 06:00 to 23:10 and it will take you about 180~200 minutes and cost you KRW 23,100(Deluxe) as of April 2013
For more information: http://www.airport.kr/eng/
2. Get off the Government Complex Daejeon bus stop
You take a taxi to get to hotels or National institute for mathematical science upon arrival at Government Complex Dejeon bus stop. It takes you around 5~10 minutes by taxi and cost about KRW 4,000~5,000. Print and show this page to the driver, please.
Way 2 Incheon Int'l Airport → Seoul Station → Daejeon Station → National institute for mathematical science(NIMS)
1. Incheon Int'l Airport → Seoul Station
By Airport limousine bus
You can buy the limousine bus tickets for Seoul Station at the Transportation Information Counters (near the exits 4, 6, 7, 8, 11, 13 on the 1st floor). With the bus ticket, you should go to 4B, 11A, 5B, 12A, 6A, 12B (The bus stop for Seoul Station) on the 1st floor to get on the bus. The bus runs at the average interval of 30minutes from 04:50 to 23:00 and it will take you about 60~80 minutes and cost you diverse fares (from KRW 10,000 to KRW 15,000 as of April 2013) as of November 2012.
By Subway
Please take AREX(Airport Railroad train) at Incheon International Airport Station, then take off the Train at Seoul Station (KTX). The AREX runs at the average interval of 12 minutes from 05:20 to 24:00 and it will take you about 53 minutes and cost you KRW 3,950 as of April 2013.
2. Seoul Station → Daejeon Station
Use KTX of Gyeonbu Line and take off at Daejeon station (Please check the exact departure time, number of train and seat.). It will take approximately 1 hour.
3. Daejeon Station → National institute for mathematical science(NIMS) or Hotel Interciti
We strongly recommend that you take a taxi to get to NIMS or Hotel upon arrival at Daejeon Station. There are always some taxis in front of Daejeon Station waiting for fares such as you. After getting in a taxi, please tell the driver NIMS or Hotel. It will take you about 20~25minutes and cost you about KRW 8,000~9000. Print and show this page to the driver, please.
Daejeon is located about 180km southeast of Gimpo International Airport. The bus boarding location at the airport is 1. The inter-city(town) bus fare is 13,500 won (KRW). The bus stop is Government Complex Building, Daejeon.
If you are taking the train, take the express train from Gimpo International Airport to Seoul Station. (1,250 won / 10 min). And then take KTX(Korea Train Express) from Seoul station to Daejeon station (23,700 won / 60 min). Then take a taxi to NIMS or Hotel. Print and show this page to the driver, please.