Limiting CPU percentage usage per user

1- Would anyone please confirm if "database resource manage" comes only with Enterprise Edition or can run on Standard Edition ?

2- How can I set a profile for a user in a way that he/she uses only a certain
percentage of the CPU. In other word, I need to have 3 differents profiles for 3 differents users
and need to limit each to cpu usage:

user1 (profile1): 50 % CPU Usage
user2 (profile2): 30 % CPU Usage
user2 (profile3): 20 % CPU Usage

we ran standard Edition 10g (linux red had 3)

Thank you.  

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