Ontologies are widely used as data representations for knowledge bases and marking
up data on the emerging Semantic Web. Hence, techniques for managing ontol-
ogy come to the centre of any practical and general solution of knowledge-based
systems.
Challenges arise when we look a step further in order to achieve flexibility and
scalability of the ontology management. Previous works in ontology management,
primarily for ontology mapping, ontology integration and ontology evolution, have
exploited only one form or another of ontology management in restrictive settings.
However, a distributed and heterogeneous environment makes it necessary for re-
searchers in this field to consider ontology interoperability in order to achieve the
vision of the Semantic Web. Several challenges arise when we set our goal to
achieve ontology interoperability on the Web. The first one is to decide which soft-
ware engineering paradigm to employ. The issue of such a paradigm is the core of
ontology management when dynamic property is involved. It should make it easy
to model complex systems and significantly improve current practice in software
engineering. Moreover, it allows the extension of the range of applications that can
feasibly be tackled. The second challenge is to exploit frameworks based on the pro-
posed paradigm. Such a framework should make possible flexibility, interactivity,
reusability and reliability for systems which are built on it. The third challenge is
to investigate suitable mechanisms to cope with ontology mapping, integration and
evolution based on the framework. It is known that predefined rules or hypotheses
may not apply given that the environment hosting an ontology is changing over
time.
Fortunately, agents are being advocated as a next generation model for en-
gineering complex and distributed systems. Also some researchers in this field
have given a qualitative analysis to provide a justification for precisely why the
agent-based approach is well suited to engineer complex software systems. From
a multi-agent perspective, agent technology fits well in developing applications in
uncontrolled and distributed environments which require substantial support for
change. Agents in multi-agent systems (MAS) are autonomous and can engage in
interactions which are essential for any ongoing agents� actions. A MAS approach
is thus regarded as an intuitive and suitable way of modelling dynamic systems.
Following the above discussion, an agent-based framework for managing ontology
in a dynamic environment is developed. The framework has several key characteris-
tics such as flexibility and extensibility that differentiate this research from others.
Three important issues of the ontology management are also investigated. It is be-
lieved that inter-ontology processes like ontology mapping with logical semantics
are foundations of ontology-based applications. Hence, firstly, ontology mapping
is discussed. Several types of semantic relations are proposed. Following these,
the mapping mechanisms are developed. Secondly, based on the previous mapping
results, ontology integration is developed to provide abstract views for participating
organisations in the presence of a variety of ontologies. Thirdly, as an ontology is
subject to evolution in its life cycle, there must be some kind of mechanisms to
reflect their changes in corresponding interrelated ontologies. Ontology refinement
is investigated to take ontology evolution into consideration. Process algebra is
employed to catch and model information exchanges between ontologies. Agent
negotiation strategy is applied to guide corresponding ontologies to react properly.
A prototype is built to demonstrate the above design and functionalities. It is
applied to ontologies dealing with the subject of beer (type). This prototype con-
sists of four major types of agents, ranging from user agent, interface agent,
ontology agent, and functionary agent. Evaluations such as query, consistency
checking are conducted on the prototype. This shows that the framework is not
only flexible but also completely workable. All agents derived from the framework
exhibit their behaviours appropriately as expected.
| Identifer | oai:union.ndltd.org:ADTP/216561 |
| Date | January 2005 |
| Creators | Li, Li, llI@it.swin.edu.au |
| Publisher | Swinburne University of Technology. |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://www.swin.edu.au/), Copyright Li Li |
Page generated in 0.0069 seconds