3,292 research outputs found
Semantic Web Techniques to Support Interoperability in Distributed Networked Environments
We explore two Semantic Web techniques arising from ITA research into semantic alignment and interoperability in distributed networks. The first is POAF (Portable Ontology Aligned Fragments) which addresses issues relating to the portability and usage of ontology alignments. POAF uses an ontology fragmentation strategy to achieve portability, and enables subsequent usage through a form of automated ontology modularization. The second technique, SWEDER (Semantic Wrapping of Existing Data sources with Embedded Rules), is grounded in the creation of lightweight ontologies to semantically wrap existing data sources, to facilitate rapid semantic integration through representational homogeneity. The semantic integration is achieved through the creation of context ontologies which define the integrations and provide a portable definition of the integration rules in the form of embedded SPARQL construct clauses. These two Semantic Web techniques address important practical issues relevant to the potential future adoption of ontologies in distributed network environments
A Proposal for Deploying Hybrid Knowledge Bases: the ADOxx-to-GraphDB Interoperability Case
Graph Database Management Systems brought data model abstractions closer to how humans are used to handle knowledge - i.e., driven by inferences across complex relationship networks rather than by encapsulating tuples under rigid schemata. Another discipline that commonly employs graph-like structures is diagrammatic Conceptual Modeling, where intuitive, graphical means of explicating knowledge are systematically studied and formalized. Considering the common ground of graph databases, the paper proposes an integration of OWL ontologies with diagrammatic representations as enabled by the ADOxx metamodeling platform. The proposal is based on the RDF-semantics variant of OWL and leads to a particular type of hybrid knowledge bases hosted, for proof-of-concept purposes, by the GraphDB system due to its inferencing capabilities. The approach aims for complementarity and integration, providing agile diagrammatic means of creating semantic networks that are amenable to ontology-based reasoning
Components Interoperability through Mediating Connector Patterns
A key objective for ubiquitous environments is to enable system
interoperability between system's components that are highly heterogeneous. In
particular, the challenge is to embed in the system architecture the necessary
support to cope with behavioral diversity in order to allow components to
coordinate and communicate. The continuously evolving environment further asks
for an automated and on-the-fly approach. In this paper we present the design
building blocks for the dynamic and on-the-fly interoperability between
heterogeneous components. Specifically, we describe an Architectural Pattern
called Mediating Connector, that is the key enabler for communication. In
addition, we present a set of Basic Mediator Patterns, that describe the basic
mismatches which can occur when components try to interact, and their
corresponding solutions.Comment: In Proceedings WCSI 2010, arXiv:1010.233
Advanced Knowledge Technologies at the Midterm: Tools and Methods for the Semantic Web
The University of Edinburgh and research sponsors are authorised to reproduce and distribute reprints and on-line copies for their purposes notwithstanding any copyright annotation hereon. The views and conclusions contained herein are the authorâs and shouldnât be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of other parties.In a celebrated essay on the new electronic media, Marshall McLuhan wrote in 1962:Our private senses are not closed systems but are endlessly translated into each other in that experience which we call consciousness. Our extended senses, tools, technologies, through the ages, have been closed systems incapable of interplay or collective awareness. Now, in the electric age, the very
instantaneous nature of co-existence among our technological instruments has created a crisis quite new in human history. Our extended faculties and senses now constitute a single field of experience which demands that they become collectively conscious. Our technologies, like our private senses, now demand an interplay and ratio that makes rational co-existence possible. As long as our technologies were as slow as the wheel or the alphabet or money, the fact that
they were separate, closed systems was socially and psychically supportable. This is not true now when sight and sound and movement are simultaneous and global in extent. (McLuhan 1962, p.5, emphasis in original)Over forty years later, the seamless interplay that McLuhan demanded between our
technologies is still barely visible. McLuhanâs predictions of the spread, and increased importance, of electronic media have of course been borne out, and the worlds of business, science and knowledge storage and transfer have been revolutionised. Yet
the integration of electronic systems as open systems remains in its infancy.Advanced Knowledge Technologies (AKT) aims to address this problem, to create a view of knowledge and its management across its lifecycle, to research and create the
services and technologies that such unification will require. Half way through its sixyear span, the results are beginning to come through, and this paper will explore some of the services, technologies and methodologies that have been developed. We hope to give a sense in this paper of the potential for the next three years, to discuss the insights and lessons learnt in the first phase of the project, to articulate the challenges and issues that remain.The WWW provided the original context that made the AKT approach to knowledge
management (KM) possible. AKT was initially proposed in 1999, it brought together an interdisciplinary consortium with the technological breadth and complementarity to create the conditions for a unified approach to knowledge across its lifecycle. The
combination of this expertise, and the time and space afforded the consortium by the
IRC structure, suggested the opportunity for a concerted effort to develop an approach
to advanced knowledge technologies, based on the WWW as a basic infrastructure.The technological context of AKT altered for the better in the short period between the development of the proposal and the beginning of the project itself with the development of the semantic web (SW), which foresaw much more intelligent manipulation and querying of knowledge. The opportunities that the SW provided for e.g., more intelligent retrieval, put AKT in the centre of information technology innovation and knowledge management services; the AKT skill set would clearly be central for the exploitation of those opportunities.The SW, as an extension of the WWW, provides an interesting set of constraints to
the knowledge management services AKT tries to provide. As a medium for the
semantically-informed coordination of information, it has suggested a number of ways in which the objectives of AKT can be achieved, most obviously through the
provision of knowledge management services delivered over the web as opposed to the creation and provision of technologies to manage knowledge.AKT is working on the assumption that many web services will be developed and provided for users. The KM problem in the near future will be one of deciding which services are needed and of coordinating them. Many of these services will be largely or entirely legacies of the WWW, and so the capabilities of the services will vary. As well as providing useful KM services in their own right, AKT will be aiming to exploit this opportunity, by reasoning over services, brokering between them, and providing essential meta-services for SW knowledge service management.Ontologies will be a crucial tool for the SW. The AKT consortium brings a lot of expertise on ontologies together, and ontologies were always going to be a key part of the strategy. All kinds of knowledge sharing and transfer activities will be mediated by ontologies, and ontology management will be an important enabling task. Different
applications will need to cope with inconsistent ontologies, or with the problems that will follow the automatic creation of ontologies (e.g. merging of pre-existing
ontologies to create a third). Ontology mapping, and the elimination of conflicts of
reference, will be important tasks. All of these issues are discussed along with our
proposed technologies.Similarly, specifications of tasks will be used for the deployment of knowledge services over the SW, but in general it cannot be expected that in the medium term there will be standards for task (or service) specifications. The brokering metaservices
that are envisaged will have to deal with this heterogeneity.The emerging picture of the SW is one of great opportunity but it will not be a wellordered, certain or consistent environment. It will comprise many repositories of legacy data, outdated and inconsistent stores, and requirements for common understandings across divergent formalisms. There is clearly a role for standards to play to bring much of this context together; AKT is playing a significant role in these efforts. But standards take time to emerge, they take political power to enforce, and they have been known to stifle innovation (in the short term). AKT is keen to understand the balance between principled inference and statistical processing of web content. Logical inference on the Web is tough. Complex queries using traditional AI inference methods bring most distributed computer systems to their knees. Do we set up semantically well-behaved areas of the Web? Is any part of the Web in which
semantic hygiene prevails interesting enough to reason in? These and many other
questions need to be addressed if we are to provide effective knowledge technologies
for our content on the web
Towards a Semantic-Aware Collaborative Working Environment
Collaborative Working Environments (CWEs) enable an efficient collaboration between professionals, specially those settled in different locations of a company or stakeholders from different companies. This can be of great help for small and medium enterprises (SMEs), as an effective way to share information. However, it can be difficult for SMEs to have access to a fully integrated CWE providing different tools (e.g., videoconferencing, instant messaging, etc.). Currently, they may define a CWE as a combination of heterogeneous and non-integrated tools which are not able to share information between them. An integrated CWE would provide SMEs with the necessary means to collaborate, making information exchange easier. 
Detecting Mismatches between a User's and an Expert's Conceptualisations
The work presented in this paper is part of our ongoing research on applying commonsense reasoning to elicit and maintain models that represent users' conceptualisations. Such user models will enable taking into account the users' perspective of the world and will empower personalisation algorithms for the Semantic Web. A formal approach for detecting mismatches between a user's and an expert's conceptual model is outlined. The formalisation is used as the basis to develop algorithms to compare two conceptualisations defined in OWL. The algorithms are illustrated in a geographical domain using a space ontology developed at NASA, and have been tested by simulating possible user misconceptions
Semantic Web Services Provisioning
Semantic Web Services constitute an important research area, where vari ous underlying frameworks, such as WSMO and OWL-S, define Semantic Web
ontologies to describe Web services, so they can be automatically discovered,
composed, and invoked. Service discovery has been traditionally interpreted
as a functional filter in current Semantic Web Services frameworks, frequently
performed by Description Logics reasoners. However, semantic provisioning
has to be performed taking Quality-of-Service (QOS) into account, defining
user preferences that enable QOS-aware Semantic Web Service selection.
Nowadays, the research focus is actually on QOS-aware processes, so cur rent proposals are developing the field by providing QOS support to semantic
provisioning, especially in selection processes. These processes lead to opti mization problems, where the best service among a set of services has to be
selected, so Description Logics cannot be used in this context. Furthermore,
user preferences has to be semantically defined so they can be used within
selection processes.
There are several proposals that extend Semantic Web Services frameworks
allowing QOS-aware semantic provisioning. However, proposed selection
techniques are very coupled with their proposed extensions, most of them
being implemented ad hoc. Thus, there is a semantic gap between functional
descriptions (usually using WSMO or OWL-S) and user preferences, which are
specific for each proposal, using different ontologies or even non-semantic de scriptions, and depending on its corresponding ad hoc selection technique.
In this report, we give an overview of most important Semantic Web Ser vices frameworks, showing a comparison between them. Then, a thorough
analysis of state-of-the art proposals on QOS-aware semantic provisioning and
user preferences descriptions is presented, discussing about their applicabil ity, advantages, and defects. Results from this analysis motivate our research
work, which has been already materialized in two early contributions.Los servicios web semĂĄnticos constituyen un importante campo de inves tigaciĂłn, en el cual distintos frameworks, como por ejemplo WSMO y OWL-S,
definen ontologĂas de la web semĂĄntica para describir servicios web, de for ma que estos puedan ser descubiertos, compuestos e invocados de manera
automĂĄtica. El descubrimiento de servicios ha sido interpretado tradicional mente como un filtro funcional en los frameworks actuales de servicios web
semĂĄnticos, usando para ello razonadores de lĂłgica descriptiva. Sin embargo,
las tareas de aprovisionamiento semĂĄntico deberĂan tener en cuenta la calidad
del servicio, definiendo para ello preferencias de usuario de manera que sea
posible realizar una selecciĂłn de servicios web semĂĄnticos sensible a la cali dad.
Actualmente, el foco de la investigaciĂłn estĂĄ en procesos sensibles a la ca lidad, por lo que las propuestas actuales estĂĄn trabajando en este campo intro duciendo el soporte adecuado a la calidad del servicio dentro del aprovisio namiento semĂĄntico, y principalmente en las tareas de selecciĂłn. Estas tareas
desembocan en problemas de optimizaciĂłn, donde el mejor servicio de entre
un concjunto debe ser seleccionado, por lo que las lĂłgicas descriptivas no pue den ser usadas en este contexto. AdemĂĄs, las preferencias de usuario deben ser
definidas semĂĄnticamente, de forma que puedan ser usadas en las tareas de
selecciĂłn.
Existen bastantes propuestas que extienden los frameworks de servicios
web semĂĄnticos para habilitar el aprovisionamiento sensible a la calidad. Sin
embargo, las técnicas de selección propuestas estån altamente acopladas con
dichas extensiones, donde la mayorĂa de ellas implementan algoritmos ad hoc.
Por tanto, existe un salto semĂĄntico entre las descripciones funcionales (nor malmente usando WSMO o OWL-S) y las preferencias de usuario, las cuales
son definidas especĂficamente por cada propuesta, usando ontologĂas distin tas o incluso descripciones no semĂĄnticas que dependen de la correspondiente
técnica de selección ad hoc
- âŠ