In this report concepts for the process of schema integration and transformation in Federated Database Systems (FDBS) are suggested, which are exible in the integration of local and in the derivation of external schemata. An FDBS has to support diierent data models of local database systems. Furthermore, it has to ooer a means to derive external schemata, which can diier in their underlying dat...

To analyze and evaluate textbooks, researchers have either proposed scales and checklists to be filled by teachers and learners or conducted qualitative investigations of the match between SLA theories and textbook activities. This study, however, employs the microstructural approach of schema theory to scrutinize the reading passages of “Mosaic 1 Reading”. To this end, 17 passages of the textb...

Despite an increase in the number of knowledge bases published according to Semantic Web W3C standards, many of those consist primarily of instance data and lack sophisticated schemata, although the availability of such schemata would allow more powerful querying, consistency checking and debugging as well as improved inference. One of the reasons why schemata are still rare is the effort requi...