You may find access methods in web pages, e.g., of your hotels. Here are some info for your convenience in case of Hotel Sunroute, one of the nearest hotels to the conference cneter.
For Hiroshima
Bullet trains
From Tokyo Narita Airport, take trains for JR Tokyo station, take a bullet train for JR Hiroshima station.
From Kansai Osaka airport, take trains for JR Shin-Osaka station, take a bullet train for JR Hiroshima station.
From Fukuoka airport, take a train for JR Hakata station, take a bullet train for JR Hiroshima station.
limousine bus service
From Hiroshima Airport, take the bus service to "Hiroshima bus center".
For Hotels
Taxi
Once you are in the city of Hiroshima, you can take a taxi.
Tram service
From JR Hiroshima station, take line #1, get off at "Chuden-mae" stop, then 2 min. walk.
From Hiroshima bus center, take tram line #1 at "Kamiyacho-higashi" stop, get off at "Chuden-mae" stop, then 2 min. walk