Decision Support Tools for Ontological Engineering - Efficient Decision Support Systems: Practice and Challenges from Current to Future - page 56

Protégé plug-in, Onto3DViz is developed as an independent software application. It
requires as input application ontologies stored in the OWL format, which can be developed
based on IMT and by other tools or techniques. The ontology documents can be shared and
re-used by other systems.
The high-level architecture of Onto3DViz is shown in figure 1. With the ontology editor, the
user creates static knowledge models which consist of classes, properties, and relations, and
dynamic knowledge models which consist of tasks, objectives, and behaviours of the tasks
and links to the class objects. Then the files consisting of the XML and OWL represented
ontologies are loaded into Onto3DViz, which generates the 3D visualized ontology model
on the computer screen as an output. The user can then adjust the 3D model using the
computer input devices of mouse and keyboard for exploring and navigating the visualized
model.
The procedure of using Onto3DViz for ontology visualization involves nine steps. This
process is also shown in the activity diagram in Figure 2.
1. The user selects the type of knowledge to be visualized, it can be either static
knowledge only, or both static and dynamic knowledge.
2. The user selects an ontology document for loading into Onto3DViz.
3. Onto3DViz validates the OWL or XML file. If there is error, Onto3DViz will generate an
error message to the user.
4. Onto3DViz extracts the ontology model using the OWL or XML parser and pass the
retrieved information to the 3D graphic engine.
5. Onto3DViz generates the 3D ontology models.
6. The 3D graphic engine generates visual objects and visual effects.
7. The GUI displays the ontology 3D visualization model on the screen.
8. The user can adjust the viewing of the 3D visualization model by using the computer
keyboard or mouse.
9. Onto3DViz provides adjusted views according to the user's preferences.
The modeling process assumes the user to have no programming knowledge. The tool is
designed so that when the user loads a compatible and valid ontology document to
Onto3DViz, a visualized ontology model will be constructed and displayed in 3D on the
computer screen.

3.1.1 Knowledge extraction and interpolation
After an application ontology has been constructed using a tool like Dyna (Harrison &
Chan, 2009) both the static and dynamic knowledge elements are stored in the XML files,
which can be shared and re-used by other systems. Instead of being connected to an
ontology editor that generates an application ontology, Onto3DViz is a separate stand-alone
system that uses OWL and XML documents as inputs for 3D ontology visualization. The
benefit of this approach is that Onto3DViz can produce a 3D ontology visualization as long
as it receives a valid ontology document from another system or via the network. Since the
formats of OWL and XML are well standardized and recognizable, the only requirement for
using Onto3DViz is that a valid ontology document is available to the system in either
format. Onto3DViz processes a valid OWL or XML formatted ontology file as follows:
1.

Import Ontology
a.

If the ontology includes only static knowledge, the user provides a correct path of
the ontology file to Onto3DViz so that it can import it.