I'd do a search for that IP and see if it's been used by a registered user.

SQL Query
select USER_ID
from ubbt_USER_DATA
where USER_LAST_IP = '221.130.193.14'

SQL Query
select USER_ID
from ubbt_POSTS
where POST_POSTER_IP = '221.130.193.14'
and USER_ID <> 1

SQL Query
select USER_ID
from ubbt_USERS
where USER_REGISTRATION_IP = '221.130.193.14'