Firstly, the systematic structure of Web database application program of multi-tier distributed B/S(Browser/Server)computational model is put forward and compared with the systematic structure of database application program of traditional two-tier C/S(Client/Server) computational model .Then,emphatic research is done for Delphi technology----the technology of MIDAS(Multi-tIer Distributed Application Services suite)---- of realizing Web database application program of multi-tier distributed B/S computational model.Lastly, applicability of multi-tier distributed B/S computational model is simply discussed.
Distributed multimedia database is the distributed database and multimedia database combination. Distributed mass of large distributed database multimedia database, especially in recent years in education, health, culture, tourism, government administration, commerce and other aspects of a wide range of applications. Based on the study of distributed large-scale multimedia database technology, the combination of multimedia database construction project is given the browser database — middleware file system (or hyperlink) the four architecture of the distributed multimedia database model; database for the system selection, development tools, development environment and data organization were discussed.
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.