An Ontology for Digital Forensics in IT Security Incidents - OPUS

40 CHAPTER 5. ONTOLOGY
Gephi and Cytoscape visualization tools might provide a nicer output
but it takes much more time to get them to do what is wanted.
5.2.7 Raptor RDF and GraphViz
There is another possibility to create graphical representations of the ontology.
Raptor RDF [Beckett, 2013] is a RDF parser that can output the
data of the RDF le in the dot format of GraphViz[Ellson et al., 2013].
GraphViz then converts the dot le to an image le. For example, the
command rapper -I . -o dot sample.rdf | dot -Tpng -o sample.png
converts a RDF le named sample.rdf to a PNG image le called sample.png.
All gures in this work that show graphs or graph-like structures are generated
from dot les.
5.3 Storage
This section presents the two storage possibilities that were used when creating
the example implementation. An explanation why there are two and
which ones were used in the end is given in section 7.5.
5.3.1 Neo4J
Neo4J [Neo Technology, Inc, 2013] is a graph database that is implemented
in Java. Graph means property graph. It consists of nodes and relationships.
Both of them have properties and the relationships structure the nodes. This
structure is visualized in gure 5.3. According to [Neo Technology, Inc., 2006]
relational databases do not support the recently upcoming amount of data
that is structured in networks. Neo4J is designed to t the requirements of
this kind of data. Additionally, the Neo4J database is preferably to be used
with semi-structured data. Semi-structured data can be thought of as a table
where the entries have few mandatory attributes but many optional ones.
But a drawback is that arbitrary queries on structured data are not handled
as eciently as in relational databases. This is caused by the network focused
design. Neo4J has a graphical web front end which allows interactive
browsing of the database. A screenshot of this interface can be found in the
appendix in gure C.1.
5.3.2 Sesame
Sesame is an open source Java framework for storage and querying of RDF
data.[Aduna, 2012] Sesame is a triplestore that is designed for storing and
retrieving triples. The web interface allows browsing the stored data and
direct SPARQL queries.