AKT EPrints Archive
(476 recursos)
Publications from the Advanced Knowledge Technologies project (AKT).
Mostrando recursos 1 - 20 de 23
1.
Formalising concepts of species, sex and developmental stage in anatomical ontologies. - Aitken, Stuart
Motivation: Anatomy ontologies have a growing role in bioinformaticsfor example, in indexing gene expression data in model organisms. To relate or draw conclusions from data so indexed, anatomy ontologies must be equipped with the formal vocabulary that would allow statements about meronomy to be qualified by constraints such as part of the male or part at the embryonic stage. Lacking such a vocabulary, anatomists have built this information into the structure of the ontology or into anatomical terms. For example, in the FlyBase anatomy for drosophila, the term larval abdominal segment encodes the stage in the term, while the terms...
2.
An ontological account of action in processes and plans - Aitken, Stuart
This paper formalises the constraints governing the relationship between actions and their preconditions and effects in processes and plans. By providing axiomatisations and a model theory, we establish a sound basis for both deductive and constraint satisfaction-based reasoning. The constraints we present are expressed in a common ontology of classes and relations that is the basis of process and plan representations.
3.
Inconsistencies, Negations and Changes in Ontologies - Flouris, G; Huang, Z; Pan, J Z; Plexousakis, D; Wache, H
Ontology management and maintenance are considered cornerstone
issues in current Semantic Web applications in
which semantic integration and ontological reasoning play
a fundamental role. The ability to deal with inconsistency
and to accommodate change is of utmost importance in realworld
applications of ontological reasoning and management,
wherein the need for expressing negated assertions also arises
naturally. For this purpose, precise, formal definitions of the
the different types of inconsistency and negation in ontologies
are required. Unfortunately, ontology languages based on
Description Logics (DLs) do not provide enough expressive
power to represent axiom negations. Furthermore, there is no
single, well-accepted notion of inconsistency and negation in
the Semantic Web community, due to the lack...
4.
A Fine-Grained Approach to Resolving Unsatisfiable Ontologies - Lam, S J; Pan, J; Sleeman, D; Vasconcelos, W
In the Semantic Web, inconsistencies in OWL ontologies may easily occur. Existing approaches either identify the minimally unsatisfiable sub-ontologies
or calculate the maximally satisfiable sub-ontologies.
However practical problems remain; it is not clear
which axioms or which parts of axioms should be selected for repair, and how to repair those axioms. In
this paper, we address this limitation by proposing a
¯ne-grained approach to resolving unsatisfiable ontologies. We revise the axiom tracing technique first proposed by Baader and Hollunder, so as to track which
parts of the problematic axioms cause the unsatisfiability. Moreover, we support ontology users in rewriting
problematic axioms. In order to minimise the impact...
5.
ONTOSEARCH2: Searching and Querying Web Ontologies - Pan, J Z; Thomas, E J; Sleeman, D H
Ontologies are important components of web-based applications. While the Web makes an increasing number of
ontologies widely available for applications, how to discover ontologies in the Web becomes a more challenging issue.
Existing approaches are mainly based on keywords and metadata information of ontologies, rather than semantic
entailments of ontologies. In this paper, we present a Semantic Web engine, called ONTOSEARCH2, which searches and
queries Web ontologies by creating and storing a copy of ontologies in a tractable description logic. ONTOSEARCH2
allows formal querying of its repository, including both the structures and instances of ontologies, using the SPARQL
query language. Furthermore, this paper reports on preliminary,...
6.
CleanONTO: Evaluating Taxonomic Relationships in Ontologies - Sleeman, D; Reul, Q H
Consistent ontologies are vital for the growth of the Semantic Web. We describe and appraise the OntoClean methodology and the different implementations available to evaluate taxonomic relationships in ontologies. We propose a
new system, CleanONTO, which uses definitions to describe
each concept, where definitions are paths from the concept
to the root node of the ontology. In the current study, these
definitions (paths) have been extracted from WordNet.
7.
Ontology Selection: Ontology Evaluation on the Real Semantic Web - Sabou, Marta; Lopez, Vanessa; Motta, Enrico; Uren, Victoria
The increasing number of ontologies on the Web and the
appearance of large scale ontology repositories has brought
the topic of ontology selection in the focus of the semantic web research agenda. Our view is that ontology evaluation is core to ontology selection and that, because ontology selection is performed in an open Web environment, it brings new challenges to ontology evaluation.
Unfortunately, current research regards ontology selection
and evaluation as two separate topics. Our goal in this paper is to explore how these two tasks relate. In particular, we are interested to get a better understanding of the ontology selection task and filter...
8.
An ontology for the description and navigation through philosophical resources - Pasin, Michele; Motta, Enrico
What does it mean for a student to come to an understanding of a philosophical standpoint and can the explosion of resources now available on the web support this process, or is it inclined instead to create more confusion? We believe that a possible answer to the problem of finding a means through the morass of information on the web to the philosophical insights it conceals and can be made to reveal lies in the process of narrative pathway generation. That is, the active linking of resources into a learning path that contextualizes them with respect to one another. This...
9.
Ontology Change Management in Protégé - Liang, Mr. Yaozhong; Alani, Dr. Harith; Shadbolt, Prof. Nigel
Ontology schemas tend to change and evolve over time to meet new requirements. This change may invalidate dependent applications if there is no dynamic adaptation to the changes made to underlying ontologies. Protégé, as a popular ontology development tool, should meet the challenges addressed by the evolving ontology. In this paper, we will briefly analyse the current ontology-change management in Protégé, and propose some extensions to facilitate change traceability by external application and services.
10.
Change Management: The Core Task of Ontology Versioning and Evolution - Liang, Mr. Yaozhong; Alani, Dr. Harith; Shadbolt, Prof. Nigel
Change management as a key issue in ontology versioning and evolution is still not fully addressed, which to some extent forms a barrier against the smooth process of ontology evolution. The key issue in the support of evolving ontologies is to distinguish and recognize the changes during the process of ontology evolution. Most of the current popular work on ontology versioning do not keep a record of the changes in the ontology, thus preventing the user from tracking those changes back and forward, or to at least understand the rational behind those changes. We are proposing an approach to get...
14.
Implementing a Semantic Web Blackboard System using Jena - McKenzie, Mr Craig; Preece, Dr Alun; Gray, Prof Peter
In this paper, we discuss the need for a hybrid reasoning approach to handing Semantic
Web data and explain why we believe that the Blackboard Architecture is particularly
suitable. We describe how we have utilised it for combining ontological inference, rules
and constraint based reasoning within a Semantic Web context.
After describing the metaphor on which the Blackboard Architecture is based we introduce
the key components of the architecture: the blackboard Panels containing the solution
space facts and problem related goals and sub-goals; the differing behaviours of the associated
Knowledge Sources and how they interact with the blackboard; and, finally, the
Controller and how it manages and focuses...
15.
Reusing JessTab rules in Protégé - Corsar, D; Sleeman, D
Protégé provides a complete ontology and knowledge base management tool. Along with JESS, JessTab provides one method of rule-based reasoning over a Protégé ontology and knowledge base. However, once JessTab rules have been created for a knowledge base, they are explicitly tied to it as they name particular classes and slots, which greatly hinders their reuse with further knowledge bases. We have developed a two-phase process and a supporting tool to support the reuse of JessTab rule sets. The first phase involves changing the class and slot references in the rule set into an abstract reference; the second phase involves...
16.
The role of ontologies in creating & maintaining corporate knowledge: a case study from the aero industry - Sleeman, D; Ajit, S; Fowler, D W; Knott, D
The Designers Workbench is a system, developed to support designers in
large organizations, such as Rolls-Royce, by making sure that the design is consistent
with the specification for the particular design as well as with the companys design
rule book(s). The evolving design is described against a jet engine ontology. Currently,
to capture the constraint information, a domain expert (design engineer) has
to work with a knowledge engineer to identify the constraints, and it is then the task
of the knowledge engineer to encode these into the Workbenchs knowledge base
(KB). This is an error prone and time consuming task. It is highly desirable to relieve
the knowledge...
17.
Changing Ontology Breaks the Queries
Updating an ontology that is in use may result in inconsistencies between the ontology and the knowledge base, dependent ontologies and applications/services. Current research concentrates on the creation of ontologies and how to manage ontology changes in terms of mapping ontology versions and keeping consistent with the instances.
Very little work investigated controlling the impact on dependent applications/services; which is the aim of the system presented in this paper. The approach we propose is to make use of ontology change logs to analyse incoming RDQL queries and amend them as necessary. Revised queries can then be used to query the ontology...
18.
Ontologies Change and Queries Break: Towards a Solution - Liang, Mr. Yaozhong; Alani, Dr. Harith; Shadbolt, Prof. Nigel
Keeping track of ontology changes is becoming a critical issue for ontology-based applications. Updating an ontology
that is in use may result in inconsistencies between the ontology and the knowledge base, dependent ontologies and applications/services. Current research concentrates on the creation of ontologies and how to manage ontology changes in
terms of mapping ontology versions and keeping consistent
with the instances. Very little work investigated ontrolling
the impact on dependent applications/services; which is the
aim of the system presented in this paper. The approach we propose is to make use of ontology change logs to analyse
incoming RDQL queries and amend them as necessary. Revised queries...
19.
Enabling Active Ontology Change Management within Semantic Web-based Applications - Liang, Mr. Yaozhong
Enabling traceable ontology changes is becoming a critical issue for ontology-based applications. Updating an ontology that is in use may result in inconsistencies between the ontology and the knowledge base, dependent ontologies and applications/services. Current research concentrates on the creation of ontologies and how to manage ontology changes in terms of mapping ontology versions and keeping consistent with the instances. Very little work investigated on-the-fly keeping track of ontology changes while update (active ontology versioning) and using these information to control the impact on dependent applications/services, which is the aim of our research presented in this thesis. The approach we...
20.
The Use of Ontologies in Contextually Aware Environments - Millard, I. C.; De Roure, D. C.; Shadbolt, N. R.
In this paper we outline work in progress related to the
construction of contextually aware pervasive computing environments, through the use of semantic and knowledge technologies. Key to this activity is modelling both where and what a user is doing at any given time. We present a prototype application to illustrate this work and describe part of its implementation.
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