CONTENTS

220 IOAN ALFRED LETIA (1) AND MIHAI COSTIN (2)
This search is conducted by using the properties of the concepts in the initial domain
as targets, and the properties of the concepts in the array of available ontologies as
search space. The most common, and probably the most efficient, method employed
is the direct string search and this means that the search agent will try to find the
given attributes (as strings or text) in the processed ontologies.
The multiagent system has to extract new concepts from the search space, matching
the initial set and so, expanding it. We are using two different sets, so that we
won’t loose the initial set. The expanded one is employed when processing an ontology
to guide the search. After the current ontology is processed, the expanded set
may be kept for later usage, but the search through the next ontology has to start
from the initial set again. This assures us that the search in one ontology will not be
affected by results from another ontology. However, we can imagine a scenario where
the search should be influenced by previous findings from other ontologies - and that
is, when building a new ontology from an existing array of ontologies with a guiding
set of concepts. But this scenario will probably be taken care of in future works.
The actors of the process are agents, part of a multiagent system, agents that are
specialized for specific tasks - for example we have an agent that will take care of the
”set of concepts into lattice” transformation and an agent that will extract the search
elements from the initial domain. However, we will refer to these specific agents with
the generic name agent.
The initial context is defined by the initial domain - given by an expert in the
field and considered to contain enough information in order to describe the target of
the search - and the array of available ontologies - in our scenario, this resumes to a
couple of ontologies much like the ones we showed the snippets from.
Using this setup, we iterate through the available ontologies and we apply our
search process, process that consists of a few major steps, to be described.
From the initial domain, the agent extracts the search elements that will be used
to guide the search process itself. These search elements consist of properties and
attributes from the concepts in the domain, so basically strings. These strings will
be the target of the search process later on and will guide the agents into finding the
lattice starting points in the search space.
Also from the initial domain, the agent extracts the initial lattice, by considering
the ontology concepts to be the ”formal objects” and their attributes to be the
”formal attributes” of the lattice. This initial, or core lattice, in collaboration with
the extracted lattices from the search space will later on provide the generated lattice
and the generated lattice is our way of determinate the best ontology to use for the
given domain.
As already mentioned, we are using string search in order to find a new concept
or set of concepts that have to be added to our lattice. This part of our process might
require some help from a word thesaurus and we base our affirmation on the fact that
ontologies are mainly composed out of concepts that have a representation as a word
in a certain language. This thesaurus, and it can be something similar to WordNet 1 ,
1 http://wordnet.princeton.edu/