With the help of assisting decision,the system studied in this paper combines rule inference and case-based inference to make up for their deficiencies,giving full play to the advantages of CBR and RBR and effectively promoting accident treatment,so as to be open,fair and convenient in the responsibility determination of traffic accidents.

Automobile behind collision is the major form of expressway traffic accident, to prevent this behind colli- sion accident, the article proposes the prevention countermeasures to behind accident on expressway based on the studies on the characteristics, theory calculation and responsibility identification of behind accident.

Then the quality responsibility identification system included of program,methods,tracing institution and expert review institution was constructed.

Some security problem of bidding web sites are analyzed,such as: Commucatition confidential of tender books,authe-ntication of users,integrity of tender books,and responsibility cognizance,based on particular analyse,some advices and solutionsare given.

Traffic accident responsibility cognizance is a sort of administrative arbitration behavior and this behavior is a sort of concrete administrative behavior conducted by a administrative department, and embodies the administrative law relation; but essentially it arbitrates civil dissension, and embodies civil law relation, so it is administratively non-adior1able.

In the project \'Research on Modern Service Industry Common Service Integrate Technology\' which belongs to the 11th Five-year\'s National Key Technology R&D Program, a service which named \'responsibility cognizance\' has been raised to address this problem.