Access to Yamagata, and to the Conference Venue

From Airports to Yamagata station via train

Train time table in Japan is reliable. It is recommended to make a plan beforehand, and purchase all the tickets at the airport.
Japan Transit Planner - type in "From" (Narita-Airport, Haneda-Airport International Terminal (Keikyu), Haneda-Airport International Terminal (Monorail), etc), "To" (Yamagata), Date and time of your departure.

Narita airport → Tokyo : 58 min; Tokyo → Yamagata : 2h 47 min (by Shinkansen bullet train).
You can buy a single ticket to Yamagata at Narita airport.
10 min+ walk is needed in the large Tokyo station.

Narita airport → Nippori : 40 min; Nippori to Ueno : 3 min ; Ueno → Yamagata : 2h 39 min (by Shinkansen bullet train)
One extra local commuting train just for one stop, but it could be ultra-crowded in rush hour in the morning and evening

Narita airport → Keisei-Ueno : 45 min; Keisei-Ueno to Ueno : 20 min walk; Ueno → Yamagata : 2h 39 min
Faster and cheaper, but need a walk between two Ueno stations
If flight is late and has to stay a night, staying at Ueno is probably more convenient than Tokyo

(Monorail and Yamanote line) Haneda Airport International Terminal → Hamamatsu-cho → Tokyo, then Tokyo to Yamagata by Shinkansen bullet train
(Keikyu and Yamanote line) Haneda Airport International Terminal → Shinagawa → Tokyo, then Tokyo to Yamagata by Shinkansen bullet train

Train from Tokyo/Ueno to Sendai and then a bus from Sendai to Yamagata is another option.
Bus runs every 10-15 minutes and takes about 1 hour.
Pros: train to Sendai is more frequent and much faster and could fully compensate the time for the bus trip, and usually more robust against natural disasters.
Cons: one extra transfer, about 1,000 yen extra cost, and the chance to lose time by looking for the bus stop at Sendai
How to find the bus stop in Sendai: get out West gate, walk across the bridge towards the "Aoba" street right-side of the big building with "Loft" shop sign, and find the bus stop 22 on the left side of the street. If you find a bus terminal with many bus stops with smaller numbers, it must be a wrong place (left-side of Loft).
Where to get off the bus: you may find the English sign if you keep watching the display or you may hear the English announcement if you keep listening, but they may be easily missed. Anyway the train station will look like a train station and you won't miss.

Depending on the flight schedule, it may be necessary to make an extra stay near the Narita airport, Tokyo station, or Ueno station.
One can easily book hotels using Expedia, booking.com or other similar site of your choice.
Booking sites run by Japanese companies, such as Rakuten or Jalan may have more offers than international ones
Booking hotels in Tokyo could be less easier than booking hotels in Yamagata because of recent increasing tourist traffic to Tokyo

Car rental is not recommended at least during the conference, but it may be useful for sightseeing around Yamagata after the conference
For students, the night bus from Tokyo to Yamagata will be the extreme cost saving travel option

Conference venue (Yamagata Terrsa) is just a few minutes walking distance from the west gate of Yamagata station.
Some construction work is on-going near the venue and station. Information on actual walking route will be provided later
There are many hotels in both west and east sides of the Yamagata station
There are many restaurants, mostly in the east side of the station. One can go through the station building from/to east to/from west.
Hotel booking will be offered in the registration page, but you can also book by yourself