Information Technology Reference
In-Depth Information
the differences in both ways; the way in which the
consumer wants to use the functionality of a Web
Service, and the way in which this functionality
is made available by the Web Service back to the
consumer.
In other words, one of the most important
functionality of this model is to overcome the
enterprise Web resources heterogeneity problems
both at data and process level (Mahmoud & Marx
Gómez, 2009), in addition to have a mechanism
for dynamic composition of Web Services by
grouping them in categories and implementing
them semantically based on a predefined metadata
ontology. That will ease the dynamic composition
process by generating dynamic workflows that will
have the responsibility of composing the desired
services based on the concepts entailed from the
existing ones.
In the proposed framework, light weight
Semantic SOA-based solution will be used to
enhance information searching and retrieving
in an automated manner and the ultimate goal is
to transform the enterprise Web into a medium
through which data and applications can be au-
tomatically understood and processed.
The objective of WSMO is to define a consistent
technology for Semantic Web Services by pro-
viding the means for semi-automated discovery,
composition and execution of Web Services based
on logical inference-mechanisms. WSMO applies
Web Service Modeling Language (WSML) as the
underlying language based on different logical
formalisms (Bussler & Fensel, 2002).
WSMO defines four main modeling elements
for describing several aspects of Semantic Web
Services (SWS) (Bruijn et al., 2007):
•
Ontologies: Are formal explicit speci-
fications of a shared conceptualization
(Gruber, 1993). They link machine and hu-
man terminologies.
•
Goals: Provide the means to express a high
level description of a concrete task.
•
Web Services: Define various aspects of
Web Services' capabilities.
•
Mediators: Bypass interpretability prob-
lems and there are four types of mediators:
OO-Mediators that have the role of resolv-
ing possible representation mismatches
between ontologies, GG-Mediators that
have the role of linking two goals, WG-
Mediators that link Web Services to goals,
meaning that the Web Service can fulfill
the goal to which it is linked and finally the
WW-Mediators that are used for linking
two Web Services in the context of auto-
matic composition of Web Services.
conceptual frameworks
There are two main conceptual frameworks deal-
ing with Semantic Web Services and defining main
elements to semantically describe services: Web
Service Modeling Ontology (WSMO) (Bussler
et al., 2004) and Web Ontology Language for
Services (OWL-S) (Burstein et al., 2004).
In addition, we are going to describe two ex-
ecution environments: Internet Reasoning Service
(IRS-III) (Cabral et al. 2004) and Web Service
Execution Environment (WSMX) (Cimpian et
al., 2005) that are following conceptual models
defined in WSMO.
WSMO is a formal model for describing
various aspects related to Semantic Web Services,
and it is based on the Web Service Modeling
Framework (WSMF) (Bussler & Fensel, 2002).
OWL-S is ontology for describing Semantic
Web Services represented in OWL. It combines
the expressivity of description logics and the
pragmatism found in the emerging Web Services
standards, to describe services that can be ex-
pressed semantically and yet grounded within a
well-defined data typing formalism. It is comprised
of three top-level notions:
•
Service Profile: Describes both the func-
tional and non-functional properties of a
Search WWH ::
Custom Search