110 research outputs found
Strengths and Limitations of Formal Ontologies in the Biomedical Domain
We propose a typology of representational artifacts for health care and life sciences domains and associate this typology with different kinds of formal ontology and logic, drawing conclusions as to the strengths and limitations for ontology in a description logics framework. The four types of domain representation we consider are: (i) lexico-semantic representation, (ii) representation of types of entities, (iii) representations of background knowledge, and (iv) representation of individuals. We advocate a clear distinction of the four kinds of representation in order to provide a more rational basis for using ontologies and related artifacts to advance integration of data and enhance interoperability of associated reasoning systems. We highlight the fact that only a minor portion of scientifically relevant facts in a domain such as biomedicine can be adequately represented by formal ontologies as long as the latter are conceived as representations of entity types. In particular, the attempt to encode default or probabilistic knowledge using ontologies so conceived is prone to produce unintended, erroneous models
Natural Language-based Approach for Helping in the Reuse of Ontology Design Patterns
Experiments in the reuse of Ontology Design Patterns (ODPs) have
revealed that users with different levels of expertise in ontology modelling face
difficulties when reusing ODPs. With the aim of tackling this problem we propose
a method and a tool for supporting a semi-automatic reuse of ODPs that
takes as input formulations in natural language (NL) of the domain aspect to be
modelled, and obtains as output a set of ODPs for solving the initial ontological
needs. The correspondence between ODPs and NL formulations is done
through Lexico-Syntactic Patterns, linguistic constructs that convey the semantic
relations present in ODPs, and which constitute the main contribution of this
paper. The main benefit of the proposed approach is the use of non-restricted
NL formulations in various languages for obtaining ODPs. The use of full NL
poses challenges in the disambiguation of linguistic expressions that we expect
to solve with user interaction, among other strategies
Automatically Drafting Ontologies from Competency Questions with FrODO
We present the Frame-based ontology Design Outlet (FrODO), a novel method and
tool for drafting ontologies from competency questions automatically.
Competency questions are expressed as natural language and are a common
solution for representing requirements in a number of agile ontology
engineering methodologies, such as the eXtreme Design (XD) or SAMOD. FrODO
builds on top of FRED. In fact, it leverages the frame semantics for drawing
domain-relevant boundaries around the RDF produced by FRED from a competency
question, thus drafting domain ontologies. We carried out a user-based study
for assessing FrODO in supporting engineers for ontology design tasks. The
study shows that FrODO is effective in this and the resulting ontology drafts
are qualitative.Comment: 15 page
Creation and extension of ontologies for describing communications in the context of organizations
Thesis submitted to Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa, in partial fulfillment of the requirements for the degree of Master in Computer ScienceThe use of ontologies is nowadays a sufficiently mature and solid field of work to be considered an efficient alternative in knowledge representation. With the crescent growth of the Semantic Web, it is expectable that this alternative tends to emerge even more in the near future.
In the context of a collaboration established between FCT-UNL and the R&D department of a national software company, a new solution entitled ECC – Enterprise Communications Center was developed. This application provides a solution to manage the communications that enter, leave or are made within an organization, and includes intelligent classification of communications and conceptual search techniques in a communications repository. As specificity may be the key to obtain acceptable results with these processes, the use of ontologies becomes crucial to represent the existing knowledge about the specific domain of an organization.
This work allowed us to guarantee a core set of ontologies that have the power of expressing the general context of the communications made in an organization, and of a methodology based upon a series of concrete steps that provides an effective capability of extending the ontologies to any business domain. By applying these steps, the minimization of the conceptualization and setup effort in new organizations and business domains is guaranteed.
The adequacy of the core set of ontologies chosen and of the methodology specified is demonstrated in this thesis by its effective application to a real case-study, which allowed us to work with the different types of sources considered in the methodology and the activities that support its construction and evolution
Get my pizza right: Repairing missing is-a relations in ALC ontologies (extended version)
With the increased use of ontologies in semantically-enabled applications,
the issue of debugging defects in ontologies has become increasingly important.
These defects can lead to wrong or incomplete results for the applications.
Debugging consists of the phases of detection and repairing. In this paper we
focus on the repairing phase of a particular kind of defects, i.e. the missing
relations in the is-a hierarchy. Previous work has dealt with the case of
taxonomies. In this work we extend the scope to deal with ALC ontologies that
can be represented using acyclic terminologies. We present algorithms and
discuss a system
Reasoning-Supported Quality Assurance for Knowledge Bases
The increasing application of ontology reuse and automated knowledge acquisition tools in ontology engineering brings about a shift of development efforts from knowledge modeling towards quality assurance. Despite the high practical importance, there has been a substantial lack of support for ensuring semantic accuracy and conciseness. In this thesis, we make a significant step forward in ontology engineering by developing a support for two such essential quality assurance activities
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