Time and change are notions that seems unavoidable in some areas of work and investigation, languages that can deal with these notions are necessary. At the same time, methods for a proper time handling are quite complex, mainly because problem’s…

Nowadays, data intensive applications are in constant demand and there is need of computing environments with better intelligent capabilities than those present in today's Database Management Systems (DBMS). To build such systems we need formalisms that can perform complicate inferences,…

A Federated System is a collection of independent, cooperative, possibly heterogeneous and autonomous computer systems (usually database systems) which allows sharing all or some of its data. A Service-oriented Architecture is an application architecture whose functionalities are defined as independent…