On-line Information Services for Trade Fairs and Congresses based
on Multimedia Databases
by Thomas Klement, Thomas Risse, Matthias Hemmje, Martin Leissler
and Matthias Malsy
Based on the fast development of high speed communication networks,
the increasing convergence of multimedia standards and virtual
reality (VR) standards establishes a growing need for technological
integration in the domain of online multimedia information systems.
The availability of such electronic publication- and information
systems also leads to new requirements in the application context
of trade fair and congress information systems. New forms of information
acquisition and usage are enabled by means of interactive multimedia
catalogue systems and interactive virtual-reality applications.
In cooperation with leading trade fair and congress organizers,
the Integrated Publication and Information Systems Institute of
GMD in Darmstadt is designing, specifying and testing an online
multimedia catalogue system based on an object relational data
base management system (DBMS). It enables the efficient and flexible
acquisition, management and maintenance of online catalogue information
for trade fairs and congresses. Among others, the main advantages
of the chosen design are:
- an intuitive design of the user interface, based on a hierarchical
catalogue metaphor and a focus- context based user interface layout
- context oriented search functions and navigation support
- transparent access to multimedia document information
- easy customization of user interface supporting fast and efficient
changes in the graphical appearance of corporate designs or product
designs
- flexible and transparent integration of operational data
- support for 3D virtual reality visualizations based on operational
application data.
The online multimedia catalogue system is based on the so called
Information Catalog Environment (ICE) components which were developed
by research divisions of GMD Institute for Integrated Publication
and Information Systems. The software components extend an object
relational DBMS with advanced functionality for providing multidimensional
catalogue support and structured management of dynamic text, multimedia
and VR document collections. The database extensions are realized
on the basis of the so-called Object Relational DataBlade technology
of Informaix Dynamic Server. Both, the structuring and navigation
support and the virtual reality visualization support within the
ICE and the VRML (Virtual Reality Modeling Language) DataBlade
Modules are described in this article.
Hierarchical and Multidimensional Categorization
The ICE-system represents and manages an arbitrary number of independent
hierarchical tree structures, so called ICE-Dimensions. These
are categorizing documents w.r.t. their content or application-oriented
usage. According to the depth of the hierarchy, the documents
are categorized at an increasing level of detail for each ICE
dimension. A mapping function between documents and leaves of
an ICE dimension¥s categorization hierarchy specifies a multidimensional,
hierarchical coordinate in the overall ICE document-space. This
so-called polyhierarchical classification enables an automatic
(which means a DBMS-supported) search for documents in similar
positions. These are documents which differ only in one leave
or a definite amount of leaves.
Within the user interface, the ICE navigation menus are dynamically
generated on each request of a document. This generation of navigation
support menus is based on the polyhierarchical representation
of the overall document space. In this way, inconsistent links
are avoided because a document, once deleted from the document
space, will not be generated as a navigatable part of an ICE navigation
menu any more. By usage of ICE, an application developer will
typically create a focus and context sensitive user interface
for preparing an interactive browsing or search-oriented access
to a document collection. The focus of the application¥s user
interface will display documents of the current position in the
document collection while the context area will display the navigation
menus. This means, ICE navigation menus visualize the position
of the documents within the ICE document space.
Features of the ICE DataBlade Module
The ICE DataBlade Module provides a set of Structured Query Language
(SQL) data types and functions which simplifies and supports the
handling of polyhirarchical ICE tables and structures. This includes
the definition and use of document templates and patterns which
define default documents for subpartitions of the overall document
space. Furthermore, the ICE DataBlade Module consists of functions
that automatically generate web based user interfaces menus supporting
user navigation and information retrieval by query by exchange
(QBE) forms.
Congress Online - an ICE application
The ICE approach is currently being applied in the Congress Online
project. It designs a system for electronic congress information
for a leading European congress organizer. Congress Online implements
electronic support to distribute congress information, to register
congresses, to submit and evaluate abstracts, and to support travel
and hotel reservation. Additionally Congress Online supports innovative
marketing oriented information services which are seamlessly integrated
into the congress information services.
Integration aspects
The integration of the ICE DataBlade Module into the INFORMIX
Web Integration Module allows the embedding of ICE-functions into
documents. Further integration with a Text DataBlade Module enables
the full text indexing of all documents within the ICE system.
Furthermore, the ICE system can be combined with the INFORMIX
Image DataBlade to support DBMS based image catalogue applications.
Further integration with the VRML DataBlade has also been developed
in GMD Institute for Integrated Publication and Information Systems.
The functionality of this DataBlade will be described below.
Virtual Trade Fair - a VRML application
Within an online multimedia congress and trade fair catalogue,
a virtual-reality overview of a trade fair hall can display information
about all companies exhibiting their products on stalls in the
hall. The possibility of walking through a three dimensional visualization
of the trade fair hall, enables visitors to plan their routes
through the trade fair more easily, long before the actual visit
takes place. The benefits for exhibitors are, eg, that they get
an impression of their stand and its position among competitor’s
stalls. Furthermore, the visualization of the hall and stands
could be used as a metaphor to access further information about
the exhibitors and their products, or to send requests for meeting
appointments to staff members of the exhibitors.
The description language VRML is widely used on the internet to
describe three dimensional scenes. The VRML-DataBlade extends
an object relational database with the ability to archive and
work on VRML scenes. With the VRML data type, which is realized
through the VRML DataBlade, is it possible to store scenes directly
in the tables of the database. The VRML data type also introduces
new functions to handle such VRML objects on the SQL level like
any other data type (eg text or numbers). The functions allows
the programmer, for example, to select several scenes from a table
and summarize the result into a new VRML scene.
Further Demands for Information Visualization
Due to increasing amount of often complex structured data collections
within global networks, appropriate visualization methods to support
information retrieval (ie, browsing and search) tasks and data
mining tasks for naive end users of information systems gain growing
importance. The available graphics performance of network client
systems is steadily growing, too. Therefore, methods for three-dimensional
visualization can be applied more and more easily.
Supporting Dynamic VRML Scenes with the VRML DataBlade
A specific ability of the VRML DataBlade is to support information
visualization by means of generating new VRML scenes from operational
data through the dynamic embedding of data into VRML scenes. Therefore,
it is possible to use the VRML DataBlade as a VRML library within
the DBMS enabling the SQL-based development of information visualization
applications. The VRML DataBlade supports information visualization
by means of a so called Server Side Include mechanism. This means
that special VRML nodes containing SQL database queries are included
within regular VRML scenes.
These nodes can also contain templates that are used to generate
new VRML nodes to visualize the query result. The database query
is processed during a request upon the dynamic VRML scene. For
each row of a result set, new VRML nodes are instantiated based
on the specified template. Therefore, the generated scene is an
information visualization of the respective database query. The
resulting scene is then sent to the client as a static VRML representation.
With this method, it is easy to generate, eg, the virtual-reality-based
user interface of the trade fair information system, mentioned
above, based on operational data from traditional relational business
database applications.
Outlook
In addition to the ICE and VRML DataBlade, three other DataBlades
are the object of research and development at GMD Institute for
Integrated Publication and Information Systems. Soon, a first
implementation of an MPEG (Motion Picture Expert Group) DataBlade
will be finished, enabling a tight DBMS supported integration
of media types like sound, images and video into the already existing
catalog and virtual reality environments. Furthermore, the MPEG
DataBlade can be applied for the DBMS-supported management and
processing of digital video.
More information on the Web at: http://www.darmstadt.gmd.de/~klement/congressonline/congressonlinee.html
Please contact:
Matthias Hemmje - GMD
Tel: +49 6151 869 844
E-mail: matthias.hemmje@gmd.de
