The street address of LUT (where the conference is held) is Skinnarilankatu 34, 53850 Lappeenranta.

If you use a car, there is a plenty of free parking space next to the university.

If you arrive by a train (VR), there is about 1km distance to the city center, where the accommodation takes place. You can walk (!) or use bus line number 5. Bus line 5 also continues from city center to LUT. It operates every half an hour. LUT is located about 6km from the city center. 
From city center to LUT (and vice versa) you can also use bus lines 1 and 3.

Local bus information and schedules. 
A little bit of finnish-english translation:

KOULUKATU = City center
MATKAKESKUS = Train station 

The taxi between train station/city center to LUT will cost you around 25e. Local taxi number is +358 200 60 400 .

Google Maps link showing all the important locations.