Logo do repositório

Percorrer por autor "Silva, Nuno"

A mostrar 1 - 10 de 11
  • Adaptive Learning Process for the Evolution of Ontology-Described Classification Model in Big Data Context
    Publication . Peixoto, Rafael; Cruz, Christophe; Silva, Nuno
    One of the biggest challenges in Big Data is to exploit value from large volumes of variable and changing data. For this, one must focus on analyzing the data in these Big Data sources and classify the data items according to a domain model (e.g. an ontology). To automatically classify unstructured text documents according to an ontology, a hierarchical multi-label classification process called Semantic HMC was proposed. This process uses ontologies to describe the classification model. To prevent cold start and user overload, the classification process automatically learns the ontology-described classification model from a very large set of unstructured text documents. However, data is always being generated and its statistical properties can change over time. In order to learn in such environment, the classification processes must handle streams of non-stationary data to adapt the classification model. This paper proposes a new adaptive learning process to consistently adapt the ontologydescribed classification model according to a non-stationary stream of unstructured text data in Big Data context. The adaptive process is then instantiated for the specific case of of the previously proposed Semantic HMC.
    2016Artigo científico Acesso restrito Ver mais
  • Age effect on kinematic variables of stepping after multidirectional disturbances
    Publication . Silva, Nuno; Melo, Cristina; Mesquita Montes, António; Crasto, Carlos; Santos, Rita
    Systems with influence on postural control suffer structural and functional changes with aging. Therefore stepping strategies against external disturbances, may have different characteristics between individuals of different age groups. Objectives: To analyze step length, step average speed and step latency on forward-backward disturbances, as well as stepping strategies after lateral disturbances. The relationship between lower limb dominance and response limb was also analyzed.
    2015-11Documento de conferência Acesso aberto Ver mais
  • Extended-spectrum β-lactamases from the North of Portugal in the boundaries to Spain: emergence of high resistance to 4th generation cephalosporins
    Publication . Fernandes, Rúben; Ferraz, Ricardo; Vieira, Mónica; Amador, Paula; Brito, Luísa; Coelho, Pedro; Silva, Nuno; Oliveira, C.; Prudêncio, Cristina
    During the past 15 years, emergence and dissemination of third-generation cephalosporins resistance in nosocomial Enterobacteriaceae became a serious problem worldwide, due to the production of extended-spectrum-β-lactamases (ESBLs). The aim of this study was to investigate among the presence of ESBL-producing enterobacteria among Portuguese clinical isolates nearby Spain, to investigate the antimicrobial susceptibility patterns and to compare the two countries. The β-lactamases genes, blaTEM, blaSHV and blaCTX-M were detected by molecular methods. Among the ESBL-producing isolates it was found extraordinary levels (98.9%) of resistance to the fourth-generation cephalosporin Cefepime. These findings point to the need of reevaluate the definition of ESBL.
    2010Documento de conferência Acesso aberto Ver mais
  • Infrastructures and scheduling method for holonic manufacturing systems
    Publication . Silva, Nuno; Ramos, Carlos
    Manufacturing systems are changing structure and organisation. Supply chains are evolving to more coupled organisations like virtual enterprises, though maintaining the single entities autonomy, adaptability and dynamism properties. Such organisations imply organisational and technological shift through agility, distribution, decentralisation, reactivity and flexibility. New organisational and technological paradigms are needed in order to reply to the modern manufacturing systems challenges. The paper proposes and justifies the holonic manufacturing system concept as the main organisational paradigm presents the infrastructures needed to assure system operation, security, coherence and coordination. Additionally, the scheduling sub-system is presented along with a scheduling method developed as a case study.
    1999-07-24Documento de conferência Acesso aberto Ver mais
  • Polimedicação em doentes em programa de reabilitação cardíaca
    Publication . Oliveira, Tiago; Silva, Nuno; Oliveira, Ana Isabel; Pinho, Cláudia; Ferraz Oliveira, Rita
    Polimedicação consiste na utilização de cinco ou mais medicamentos. Programas de Reabilitação Cardíaca (PRC) permitem otimizar a recuperação funcional do doente que sofreu um acidente cardiovascular, melhorar a qualidade de vida e reduzir o risco de complicações.
    2023-05Documento de conferência Acesso aberto Ver mais
  • Polimorfismo I/D do gene da enzima conversora da angiotensina
    Publication . Fernandes, Rúben; Prudêncio, Cristina; Duarte, Fernanda; Silva, Nuno; Silva, Ana Luísa
    Em Portugal, no ano de 2009, existiam 983 mil indivíduos com Diabetes mellitus (DM), dos quais 90% DM tipo 2 (DM2). Um dos principais factores de risco para o desenvolvimento da DM2 é a obesidade. A DM2 está, desta forma, associada a um estilo de vida sedentário, quer pela diminuição do metabolismo da glicose, quer pela sua associação à obesidade devido ao aumento dos níveis de glicose como consequência da sobrealimentação. Outros factores como a lipotoxicidade e o stress oxidativo também têm sido considerados como responsáveis pela disfunção das células-beta pancreáticas. O gene da enzima conversora da angiotensina (ECA) é altamente polimórfico, sendo associado como factor predisponente para diferentes patologias como a DM. O polimorfismo melhor descrito até à actualidade é o de Inserção/Delecção (I/D), consistindo na inserção de um fragmento Alu de 287bp no intrão 16 do gene DCP1. A actividade pró-inflamatória e pró-oxidativa desta enzima sobre o pâncreas, bem como a sua actuação nos processos de fibrose, podem em parte auxiliar na compreensão do processo que origina esta patologia. O polimorfismo I/D torna-se assim um óptimo candidato para a detecção de indivíduos susceptíveis.Este estudo tem como objectivo analisar a distribuição do polimorfismo I/D, bem como a sua possível relação com a incidência de DM e com os níveis de glicose.
    2011Documento de conferência Acesso aberto Ver mais
  • Proposal for the combination of ontology assemble and ontology mapping processes
    Publication . Silva, Nuno; Santos, Jorge; Rocha, João; Ramos, Carlos; Vale, Zita
    Ontology mapping is dependent on the matching algorithms, which in turn depends on the semantics of the ontologies. This proposal grounds on two distinct technologies: ontology mapping and ontology assemble. The ontology mapping system is a service-oriented system in which autonomous plug-able services capture and represent the ontology mapping domain’s expertise. Automatic ontology mapping systems perform poorly due to the lack of ontologies’ semantics to reason upon. The assemble process aims to integrate well-founded, proofed knowledge into the domain ontologies, providing extra semantics. Exploiting such semantics indistinct phases of the ontology mapping process, we envisage that such semantics would be very useful in the improvement of the automatic mapping results. Conversely, the ontology mapping experiences would provide feed-back to the assemble process, suggesting its improvement too. The cyclic improvement would run indefinitely. This paper suggests therefore the combination of efforts from both the assemble and mapping processes towards a better semantic relations and assembled ontologies.
    2004-07-23Comunicação em conferência Acesso aberto Ver mais
  • Reabilitação desportiva de fractura diafisária da tíbia e perónio
    Publication . Silva, Nuno; Carvalho, Paulo
    O estágio no âmbito do Mestrado em Fisioterapia foi realizado no FC PORTO, Futebol SAD. Tendo em conta a dimensão económico-social da instituição em causa, este Portefólio deverá preservar a confidencialidade de alguns dados expostos. Todos os actos clínicos, executados na equipa de Futebol Sub-19, passíveis de ser publicados serão relatados. Representando esta modalidade, um desporto com elevado grau de lesões foi possível aplicar neste estágio alguns princípios teóricos/práticos aprendidos. Acompanhar o Clube foi uma realidade, em todas as suas acções desportivas. A integração deste estágio na equipa de trabalho foi plena. A estrutura de futebol profissional, reúne profissionais de varias áreas que repetidamente cruzam conhecimentos e tentam atingir o óptimo em função da confrontação de conceitos. Relativamente à avaliação do atleta, foi elaborada uma abordagem clínica que contempla os itens abaixo discriminados.
    2010Dissertação de mestrado Acesso aberto Ver mais
  • Service-oriented semi-automatic ontology bridging
    Publication . Silva, Nuno; Rocha, João; Ramos, Carlos; Vale, Zita
    With the advent of Semantic Web, knowledge-based interoperability faces a new technological shift, in which ontologies and semantic web technologies play a major role. Exploiting the explicit semantic description of the domain of discourse allows reasoning and automatically acquiring semantic relations between two different domains of discourses. Such semantic relations would be further applied in converting data or documents between such domains. This process is named Ontology Mapping. This paper proposes a semi-automatic bridging process, based in the idea that while automatic matching algorithms do not provide enough information to overcome semantic heterogeneity, they represent valuable sources of similarities measurements between ontologies’ entities, which can be combined into an overall similarity measure according to each service specific requirements.
    2004-07-23Comunicação em conferência Acesso aberto Ver mais
  • ß-lactamases in the biochemistry and molecular biology laboratory
    Publication . Amador, Paula; Prudêncio, Cristina; Vieira, Mónica; Ferraz, Ricardo; Fonte, Rosália; Silva, Nuno; Coelho, Pedro; Fernandes, Rúben
    β-lactamases are hydrolytic enzymes that inactivate the β-lactam ring of antibiotics such as penicillins and cephalosporins. The major diversity of studies carried out until now have mainly focused on the characterization of β-lactamases recovered among clinical isolates of Gram-positive staphylococci and Gram-negative enterobacteria, amongst others. However, only some studies refer to the detection and development of β-lactamases carriers in healthy humans, sick animals, or even in strains isolated from environmental stocks such as food, water, or soils. Considering this, we proposed a 10-week laboratory programme for the Biochemistry and Molecular Biology laboratory for majors in the health, environmental, and agronomical sciences. During those weeks, students would be dealing with some basic techniques such as DNA extraction, bacterial transformation, polymerase chain reaction (PCR), gel electrophoresis, and the use of several bioinformatics tools. These laboratory exercises would be conducted as a mini research project in which all the classes would be connected with the previous ones. This curriculum was compared in an experiment involving two groups of students from two different majors. The new curriculum, with classes linked together as a mini research project, was taught to a major in Pharmacy and an old curriculum was taught to students from environmental health. The results showed that students who were enrolled in the new curriculum obtained better results in the final exam than the students who were enrolled in the former curriculum. Likewise, these students were found to be more enthusiastic during the laboratory classes than those from the former curriculum.
    2009Artigo científico Acesso aberto Ver mais