Page 183 - E-Bussiness and E-Commerce Management Strategy, Implementation, and Practice

M03_CHAF9601_04_SE_C03.QXD:D01_CHAF7409_04_SE_C01.QXD 16/4/09 11:09 Page 150

150 Part 1 Introduction

(classes or instances) of the ontologies in our system define the meaning. Thus, users can keep using free-
keywords when tagging content, since this layer helps to solve ambiguity and heterogeneity problems, as
different tags can be related to the same resource (e.g. ‘solar’ and ‘solar_energy’ linked to
athena:SolarEnergy). Moreover, users can browse a human-readable version (using labels instead of
URLs) of the ontology in case they want to add a new link or if the tag leads to ambiguity and they must
choose the relevant resource when tagging content. Furthermore, when saving tagged content, the links
between content and resources are exported in a RDF export using SIOC and MOAT.
Each time a service produces a new document, the storage system is notified by the plug-ins of our
mediation architecture, saves its RDF data instantaneously and merges it with other data using the archi-
tecture shown in Figure 3.15. This allows us to benefit from a unique view of the many integrated data
sources (e.g. blogs, wikis, RSS) and to have access to up to date information. Then, using the SPARQL
query language and protocol, we can query across the many data sources, and services can be plugged on
top of the central storage system.

querying

mediator Ontologies Unified business data layer
Advanced services

Semantic Unified documents meta-data layer Storage

RDF

Adaptors

system

Information producing producing aggregating
Blogs
RSS Feeds
Wikis

World Wide Web

U1 U2
Architecture of semantic web system used at EDF
Figure 3.15