European Journal of Scientific Research - EuroJournals

376 Benharzallah Saber and Kazar Okba
and remains always necessary the recourse to an expert of the domain. It has a low capacity to treat
evolutionarily and the scalability especially in a multi-domain context.
2.1. The use of the SMA for the semantic mediation of the information systems
The appearance of the agent paradigm gives a new sight for the development of the of complex,
heterogeneous, distributed and/or autonomous systems nature[14]. Several projects of semantic
interoperability use the agent paradigm [15] [11]. Among work completed: The purpose of the
Infosleuth project [11] is to implement a set of cooperative agents which discover, integrate and
present information according to the needs for a user or an application for which they produce a simple
and coherent interface. The Infosleuth architecture project consists of a set of agents collaborative
communicate by ACL KQML. The users express its queries on a specific ontology. KIF and SQL are
used to represent the queries. The queries are to dispatch with the agents specialized (agent broker,
ontological, planner...) for the data retrieval on distributed sources and for integration. The resolution
of many semantic conflicts remains guided by the user [02].
3. Approach Description
3.1. Approach objectives
The objectives of our solution are the realization of a semantic mediation having the following
characteristics:
1. To allow a system which provides its context of application, to find the information systems
and information shared by those, useful to this application, of integrated dynamically into the
system and to use them in a transparent way.
2. To ensure the advantages of the context and schema mediation, and to avoid their
disadvantages. Our contribution concentrates on the dynamic change of the multi-agents
mediation system, of the context mediation to the schema mediation during the operation of the
mediation system. That is done by the use of the intelligent agents, in order to ensure the open
aspect of the context mediation (high automation degree of the query resolution process...) and
the robustness of the schema mediation (reliability of the answers by the use of the mapping
rules, the formulation of the queries in schema terms...).
3. To solve the majority of the semantic conflicts by using new technologies, and by respecting a
high automation degree of the query resolution process of semantic conflicts.
4. To build a flexible semantic mediation system makes it possible to ensure evolutionarily
(addition/withdrawal/modification of an information source) and the scalability of architecture.
3.1. A Generic architecture based agent for context and schema mediation
The cooperation suggested in our solution rests on a preliminary construction of information having to
be integrated and on the mixed query resolution static and dynamics. An information system can play
in turn the role of supplier or consumer [Figure1] of information.