| 摘要 |
PROBLEM TO BE SOLVED: To control the presence rate of medium types while managing the total number of derived information for each medium type in controlling access to derive information. SOLUTION: An access control system is configured to set a maximum allowable number of derivations for each medium type of each generation, and to record the number of derivations so far for each medium type for each derivation source information resource, and to, when the value of the presence rate calculated based on the number of derivations so far for each medium type of the derivation source information resource is equal to or more than the maximum value of the presence rate in derivation reference information 21a, set the maximum allowable number of derivations to zero, and to, when the number of derivations so far does not exceed the maximum allowable number derivations, execute the deriving operation. COPYRIGHT: (C)2011,JPO&INPIT |
