40 research outputs found

    Domain ontology learning from the web

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    El Aprendizaje de Ontolog铆as se define como el conjunto de m茅todos utilizados para construir, enriquecer o adaptar una ontolog铆a existente de forma semiautom谩tica, utilizando fuentes de informaci贸n heterog茅neas. En este proceso se emplea texto, diccionarios electr贸nicos, ontolog铆as ling眉铆sticas e informaci贸n estructurada y semiestructurada para extraer conocimiento. Recientemente, gracias al enorme crecimiento de la Sociedad de la Informaci贸n, la Web se ha convertido en una valiosa fuente de informaci贸n para casi cualquier dominio. Esto ha provocado que los investigadores empiecen a considerar a la Web como un repositorio v谩lido para Recuperar Informaci贸n y Adquirir Conocimiento. No obstante, la Web presenta algunos problemas que no se observan en repositorios de informaci贸n cl谩sicos: presentaci贸n orientada al usuario, ruido, fuentes no confiables, alta dinamicidad y tama帽o abrumador. Pese a ello, tambi茅n presenta algunas caracter铆sticas que pueden ser interesantes para la adquisici贸n de conocimiento: debido a su enorme tama帽o y heterogeneidad, se asume que la Web aproxima la distribuci贸n real de la informaci贸n a nivel global. Este trabajo describe una aproximaci贸n novedosa para el aprendizaje de ontolog铆as, presentando nuevos m茅todos para adquirir conocimiento de la Web. La propuesta se distingue de otros trabajos previos principalmente en la particular adaptaci贸n de algunas t茅cnicas cl谩sicas de aprendizaje al corpus Web y en la explotaci贸n de las caracter铆sticas interesantes del entorno Web para componer una aproximaci贸n autom谩tica, no supervisada e independiente del dominio. Con respecto al proceso de construcci贸n de la ontolog铆as, se han desarrollado los siguientes m茅todos: i) extracci贸n y selecci贸n de t茅rminos relacionados con el dominio, organiz谩ndolos de forma taxon贸mica; ii) descubrimiento y etiquetado de relaciones no taxon贸micas entre los conceptos; iii) m茅todos adicionales para mejorar la estructura final, incluyendo la detecci贸n de entidades con nombre, atributos, herencia m煤ltiple e incluso un cierto grado de desambiguaci贸n sem谩ntica. La metodolog铆a de aprendizaje al completo se ha implementado mediante un sistema distribuido basado en agentes, proporcionando una soluci贸n escalable. Tambi茅n se ha evaluado para varios dominios de conocimiento bien diferenciados, obteniendo resultados de buena calidad. Finalmente, se han desarrollado varias aplicaciones referentes a la estructuraci贸n autom谩tica de librer铆as digitales y recursos Web, y la recuperaci贸n de informaci贸n basada en ontolog铆as.Ontology Learning is defined as the set of methods used for building from scratch, enriching or adapting an existing ontology in a semi-automatic fashion using heterogeneous information sources. This data-driven procedure uses text, electronic dictionaries, linguistic ontologies and structured and semi-structured information to acquire knowledge. Recently, with the enormous growth of the Information Society, the Web has become a valuable source of information for almost every possible domain of knowledge. This has motivated researchers to start considering the Web as a valid repository for Information Retrieval and Knowledge Acquisition. However, the Web suffers from problems that are not typically observed in classical information repositories: human oriented presentation, noise, untrusted sources, high dynamicity and overwhelming size. Even though, it also presents characteristics that can be interesting for knowledge acquisition: due to its huge size and heterogeneity it has been assumed that the Web approximates the real distribution of the information in humankind. The present work introduces a novel approach for ontology learning, introducing new methods for knowledge acquisition from the Web. The adaptation of several well known learning techniques to the web corpus and the exploitation of particular characteristics of the Web environment composing an automatic, unsupervised and domain independent approach distinguishes the present proposal from previous works.With respect to the ontology building process, the following methods have been developed: i) extraction and selection of domain related terms, organising them in a taxonomical way; ii) discovery and label of non-taxonomical relationships between concepts; iii) additional methods for improving the final structure, including the detection of named entities, class features, multiple inheritance and also a certain degree of semantic disambiguation. The full learning methodology has been implemented in a distributed agent-based fashion, providing a scalable solution. It has been evaluated for several well distinguished domains of knowledge, obtaining good quality results. Finally, several direct applications have been developed, including automatic structuring of digital libraries and web resources, and ontology-based Web Information Retrieval

    BNAIC 2008:Proceedings of BNAIC 2008, the twentieth Belgian-Dutch Artificial Intelligence Conference

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    An adaptive physiology-aware communication framework for distributed medical cyber physical systems

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    For emergency medical cyber-physical systems, enhancing the safety and effectiveness of patient care, especially in remote rural areas, is essential. While the doctor to patient ratio in the United States is 30 to 10,000 in large metropolitan areas, it is only 5 to 10,000 in most rural areas; and the highest death rates are often found in the most rural counties. Use of telecommunication technologies can enhance effectiveness and safety of emergency ambulance transport of patients from rural areas to a regional center hospital. It enables remote monitoring of patients by the physician experts at the tertiary center. There are critical times during transport when physician experts can provide vital assistance to the ambulance Emergency Medical Technicians (EMT) to associate best treatments. However, the communication along the roads in rural areas can range irregularly from 4G to low speed 2G links, including some parts of routes with cellular network communication breakage. This unreliable and limited communication bandwidth together with the produced mass of clinical data and the many information exchanges pose a major challenge in real-time supervision of patients. In this study, we define the notion of distributed emergency care, and propose a novel adaptive physiology-aware communication framework which is aware of the patient condition, the underlying network bandwidth, and the criticality of clinical data in the context of the specific diseases. Using the concept of distributed medical CPS models, we study the semantics relation of communication Quality of Service (QoS) with clinical messages, criticality of clinical data, and an ambulance's undertaken route all in a disease-aware manner. Our proposed communication framework is aimed to enhance remote monitoring of acute patients during ambulance transport from a rural hospital to a regional center hospital. We evaluate the components of our framework through various experimentation phases including simulation, instrumentation, real-world profiling, and validation
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