3,814 research outputs found
Knowledge Rich Natural Language Queries over Structured Biological Databases
Increasingly, keyword, natural language and NoSQL queries are being used for
information retrieval from traditional as well as non-traditional databases
such as web, document, image, GIS, legal, and health databases. While their
popularity are undeniable for obvious reasons, their engineering is far from
simple. In most part, semantics and intent preserving mapping of a well
understood natural language query expressed over a structured database schema
to a structured query language is still a difficult task, and research to tame
the complexity is intense. In this paper, we propose a multi-level
knowledge-based middleware to facilitate such mappings that separate the
conceptual level from the physical level. We augment these multi-level
abstractions with a concept reasoner and a query strategy engine to dynamically
link arbitrary natural language querying to well defined structured queries. We
demonstrate the feasibility of our approach by presenting a Datalog based
prototype system, called BioSmart, that can compute responses to arbitrary
natural language queries over arbitrary databases once a syntactic
classification of the natural language query is made
A SPARQL query engine over Web ontologies using contextual logic programming
Na World Wide Web os programas informáticos conseguem processar facilmente a estrutura das páginas. Contudo, são necessárias técnicas avançadas para determinar o conteúdo semântico dessas páginas. A Semantic Web é uma extensão da Web que tenta ultrapassar esta dificuldade. Criar anotações nas páginas com informação acerca do seu conteúdo, descrita. Numa linguagem formal, ajuda o processamento automatizado da semântica da página. A integração dessa informação semântica, que pode ser descrita através de OWL, com uma. framework de Programação em Logica Contextual disponibiliza uma maneira clara e simples de representar e interrogar ontologias. As principais contribuições deste trabalho para esse objetivo são: - Um sistema capaz de representar ontologias OWL DL e de realizar interrogações baseadas nessa representação - Um médulo de resposta a interrogações SPARQL: permite disponibilizar o sistema a um elevado número de utilizadores e processes automáticos e possibilita anunciá-lo como um serviço Web. /ABSTRACT - In the World Wide Web a machine can easily process the structure of resources. However, more advanced techniques are necessary to determine the semantic contents of such resources. The Semantic Web is an enhancement of the Web which aims to overcome this difficulty. Annotating Web resources with information about their contents, described using a formal language, helps machines process the semantics of the resource. Integrating that semantic information, which can be described using OWL with a Contextual Logic Programming framework provides a clear and simple way to represent and query an ontology. The main contributions of this work to that purpose are: - A system capable of representing OWL DL ontologies and performing queries over that representation - A SPARQL query answering module: this makes the system available to a wide range of users and automated processes, enabling the possibility of advertising it as a web service
Survey over Existing Query and Transformation Languages
A widely acknowledged obstacle for realizing the vision of the Semantic Web is the inability
of many current Semantic Web approaches to cope with data available in such diverging
representation formalisms as XML, RDF, or Topic Maps. A common query language is the first
step to allow transparent access to data in any of these formats. To further the understanding
of the requirements and approaches proposed for query languages in the conventional as well
as the Semantic Web, this report surveys a large number of query languages for accessing
XML, RDF, or Topic Maps. This is the first systematic survey to consider query languages from
all these areas. From the detailed survey of these query languages, a common classification
scheme is derived that is useful for understanding and differentiating languages within and
among all three areas
Challenges in Bridging Social Semantics and Formal Semantics on the Web
This paper describes several results of Wimmics, a research lab which names
stands for: web-instrumented man-machine interactions, communities, and
semantics. The approaches introduced here rely on graph-oriented knowledge
representation, reasoning and operationalization to model and support actors,
actions and interactions in web-based epistemic communities. The re-search
results are applied to support and foster interactions in online communities
and manage their resources
A Formal Context Representation Framework for Network-Enabled Cognition
Network-accessible resources are inherently contextual with respect to the specific situations (e.g., location and default assumptions) in which they are used. Therefore, the explicit conceptualization and representation of contexts is required to address a number of problems in Network- Enabled Cognition (NEC). We propose a context representation framework to address the computational specification of contexts. Our focus is on developing a formal model of context for the unambiguous and effective delivery of data and knowledge, in particular, for enabling forms of automated inference that address contextual differences between agents in a distributed network environment. We identify several components for the conceptualization of contexts within the context representation framework. These include jurisdictions (which can be used to interpret contextual data), semantic assumptions (which highlight the meaning of data), provenance information and inter-context relationships. Finally, we demonstrate the application of the context representation framework in a collaborative military coalition planning scenario. We show how the framework can be used to support the representation of plan-relevant contextual information
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A monitoring approach for runtime service discovery
Effective runtime service discovery requires identification of services based on different service characteristics such as structural, behavioural, quality, and contextual characteristics. However, current service registries guarantee services described in terms of structural and sometimes quality characteristics and, therefore, it is not always possible to assume that services in them will have all the characteristics required for effective service discovery. In this paper, we describe a monitor-based runtime service discovery framework called MoRSeD. The framework supports service discovery in both push and pull modes of query execution. The push mode of query execution is performed in parallel to the execution of a service-based system, in a proactive way. Both types of queries are specified in a query language called SerDiQueL that allows the representation of structural, behavioral, quality, and contextual conditions of services to be identified. The framework uses a monitor component to verify if behavioral and contextual conditions in the queries can be satisfied by services, based on translations of these conditions into properties represented in event calculus, and verification of the satisfiability of these properties against services. The monitor is also used to support identification that services participating in a service-based system are unavailable, and identification of changes in the behavioral and contextual characteristics of the services. A prototype implementation of the framework has been developed. The framework has been evaluated in terms of comparison of its performance when using and when not using the monitor component
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