goal describes the required web service capability as
input. Semantic discovery adds accuracy to the
search results in comparison to traditional Web
service discovery techniques, which are based on
syntactical searches over keywords contained in the
web service descriptions (U. Keller, Lara R.,
Polleres A, 2004).
Improvement in matching process could be
gained by the use of ontological information in a
useful form. With the use of this information, it can
be possible to rate the services found in discovery
process. As in real life, users/ agents should be able
to define how they see the relation of ontological
concepts from their own perspective. Similarity
measures have been widely used in information
systems (Voorhees, E, 1998, Ginsberg, A., 1993,
Lee, J., M. Kim and Y. Lee, 1993), cognitive
science, software engineering and AI (Agirre, E. and
G. Rigau, 1996, Hovy, E., 1998, Wang, Y. and E.
Stroulia, 2003). So integration of knowledge from
these techniques can improve the matching process.
By using semantic distance definition
information, we aim to get a rated and ordered set of
web services as the general result of the discovery
process. We believe that this would be better than
set-based classification of discovered services. In
this paper, we propose a new scheme of
matchmaking that aims to improve retrieval
effectiveness of semantic matchmaking process. Our
main argument is that conventional evaluation
schemes do not fully capture the added value of
service semantics and they do not consider the
assigned degrees of match, which are supported by
the majority of discovery engines. The existing
approach to service matchmaking contains
subsumption values regarding the concept that the
service supports. In our proposed approach, we add
semantic relatedness values onto existing
subsumption-based procedures. We introduce value
added approaches to matchmaking process such as
property-level matching, semantic distance
information and WordNet scoring. Property-level
matching provides capturing similarity between
concepts that do not have a subsumption relation. So
that, services that would not be classified, are ranked
with our matchmaking agent. Similarity distance
provides user’s profile to be represented in the
ontology. Similarity distance weights can be
assigned on the links between concepts to specify
concepts relatedness to each other in an explicit way.
Also by making use of WordNet, we introduce a
second source of semantic repository to be utilized
in matchmaking. Our test results in section 5
indicate that these value added approaches increases
the captured semantic relations between parameters
of services and provide a better ranking of services
resulting in better user experience in matchmaking.
2 RELATED WORK
Semantic Web services aim to realize the vision of
the Semantic Web, i.e. turning the Internet from an
information repository for human consumption into
a worldwide system for distributed Web computing
(http://www.w3.org/2001/sw/, 2006.). The system is
a machine-understandable media where all the data
is combined with semantic metadata. The domain
level formalizations of concepts form up the main
element within this system, which is called ontology
(http://www.w3.org/Submission/OWL-S, 2004).
Ontology represents concepts and relations between
the concepts; these can be hierarchical relations,
whole-part relations, or any other meaningful type of
linkage between the concepts(H. El-Ghalayini, M.
Odeh, R. McClatchey, and T. Solomonides,, 2005).
The semantic matchmaking process is based on
ontology formalizations over domains. In the
upcoming section we present some of the selective
research on the matchmaking process considering
the concepts that we build our research on.
Matchmaking of Web services considers the
relationship between two services. The first one is
called the advertisement and the other is called the
request (Klusch, M., Fries, B., Khalid, M., and
Sycara, K.. 2005). Advertisement denotes the
services description of the existing services while
the request indicates the picture of service
requirements (Wang, Y. and E. Stroulia, 2003).
In (Wang, H., Zengzhi L., Fan L., 2006), the
problem of capability matchmaking is analyzed with
regarding to Web services, especially the
Preconditions and Effects (PE) matchmaking. In the
paper, the authors present a service similarity
function that determines similar parameter classes
by using a matching process over synonym sets,
semantic neighbourhood, and distinguishing
features. Parameter pairing is the process that is used
for matching service descriptions. In the work,
maximum weight bi-partite graph matching method
is utilized for parameter finding; the weights of bi-
partite graph’s edges are evaluated with matching
degree between function parameters calculated by
the similarity function mentioned above.
Although good results are obtained with the
usage of this method, it should still be improved in
two terms: One is that, it needs to be extended on
pre-condition and affect because the matching is
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