The principal component analysis could substitu te a small number comprehensive variable for original multidimensional variable and obviously simplify data structure in the precondition of minimizing loss of original data information.

A dependable for earth-air missile weapon system designing already set data information analysts calculate way has been that realm inside very tough problem.

Security and encryption technique of information data;

The encryption algorithms of information data included public key encryp- tion algorithm,symmetry secret key encryption algorithm DES transforms changing data position algorithm of data encrypfion,and electronic signature of information data package.

A great deal of information data must be inputted in space grid structural calculation.

The authors create an elementary information database for city transportation based on demand analysis, logic and physical design using delphi database technology.

Based on the water supply system of a city in North China, the municipal water supply information management and dispatching systems were developed, and water supply information database and water dispatching model -method base were set up.

Universities can establish teaching reference information database depending on its source advantage,realize the combination of e-learning and specialized teaching.