Databases Reference
In-Depth Information
the Palette into the Canvas, and connect it to the SMIL page. (10)We specify that
' ' in VD is an example, and drag and drop it into the Canvas.
(11)We put a repetition mark (*) on the dropped ' ' object. As a result, the
scenes (video objects) of a player are rendered sequentially as one video. Otherwise,
a SMIL page is produced for each scene. (12)We specify that ' ' in TP is an example,
and drag and drop it into the Canvas. (13)We specify that the 'Data' section in PP
is an example, and drag and drop it into the Canvas. (14)Finally, we press the
'Query' button on the Canvas.
Figure 11 is a screen shot of the prototype system where the user is specifying
the example scenario. These operations are analyzed in AQUA, and the data
integration requests are issued to the InfoWeaver mediator. AQUA processes the
integration result and generates the specified Web structure.
Figure 11: A screen shot of the prototype system
5
Conclusion
With the broad acceptance of the World Wide Web, the Web has been widely used
for publishing and disseminating information stored in various information sources.
Therefore, the construction of Web structures on top of the heterogeneous
information sources has become an important research issue. In this article, we
surveyed the current approaches to the problem in the first part, and showed our
approach in the second part. The current approaches to the problem can be classified
into the three approaches. Among them, we mainly explored the mediation
approach, and gave an overview of the technology related to this from a number
of important design view-points. In the second part, we introduced our approach
named InfoWeaver/AQUA. InfoWeaver provides the mediation function for data
integration. The common data model WebNR/SD is a hybrid data model based on
nested relations and ADT values representing structured documents. AQUA is a
drag-and-drop-based interactive vi sual facility for the Web structure construction
