Yes, the participant or the organizer (depending on the policy of the conference) will be charged. If you cancel/shorten your arrival:
3 nights before the beginning of the event, 1 night will be due.
2 nights before the beginning of the event, 2 nights will be due.
1 night before the beginning of the event, 3 nights will be due.
After the beginning of the event, all nights will be due.