Extraction automatique d´associations lexicales à partir de corpora

The automatic acquisition of lexical associations from corpora is a crucial issue for Natural Language Processing. A lexical association is a recurrent combination of words that co-occur together more often than expected by chance in a given domain. In fact, lexical associations define linguistic phenomena such as idiomes, collocations or compound words. Due to the fact that the sense of a lexical association is not compositionnal, their identification is fundamental for the realization of analysis and synthesis that take into account all the subtilities of the language. In this report, we introduce a new statistically-based architecture that extracts from naturally occurring texts contiguous and non contiguous. For that purpose, three new concepts have been defined : the positional N-gram models, the Mutual Expectation and the GenLocalMaxs algorithm. Thus, the initial text is fisrtly transformed in a set of positionnal N-grams i.e ordered vectors of simple lexical units. Then, an association measure, the Mutual Expectation, evaluates the degree of cohesion of each positional N-grams based on the identification of local maximum values of Mutual Expectation. Great efforts have also been carried out to evaluate our metodology. For that purpose, we have proposed the normalisation of five well-known association measures and shown that both the Mutual Expectation and the GenLocalMaxs algorithm evidence significant improvements comparing to existent metodologies.

Declarative approach to data extraction of web pages

Thesis submitted to Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa, in partial fulfilment of the requirements for the degree of Master in Computer Science

Semantic relations extraction from unstructured information for domain ontologies enrichment

Based in internet growth, through semantic web, together with communication speed improvement and fast development of storage device sizes, data and information volume rises considerably every day. Because of this, in the last few years there has been a growing interest in structures for formal representation with suitable characteristics, such as the possibility to organize data and information, as well as the reuse of its contents aimed for the generation of new knowledge. Controlled Vocabulary, specifically Ontologies, present themselves in the lead as one of such structures of representation with high potential. Not only allow for data representation, as well as the reuse of such data for knowledge extraction, coupled with its subsequent storage through not so complex formalisms. However, for the purpose of assuring that ontology knowledge is always up to date, they need maintenance. Ontology Learning is an area which studies the details of update and maintenance of ontologies. It is worth noting that relevant literature already presents first results on automatic maintenance of ontologies, but still in a very early stage. Human-based processes are still the current way to update and maintain an ontology, which turns this into a cumbersome task. The generation of new knowledge aimed for ontology growth can be done based in Data Mining techniques, which is an area that studies techniques for data processing, pattern discovery and knowledge extraction in IT systems. This work aims at proposing a novel semi-automatic method for knowledge extraction from unstructured data sources, using Data Mining techniques, namely through pattern discovery, focused in improving the precision of concept and its semantic relations present in an ontology. In order to verify the applicability of the proposed method, a proof of concept was developed, presenting its results, which were applied in building and construction sector.

Optimização da estrutura de um semi-reboque com vista à flexibilidade na sua adequação funcional

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Mecânica

Water treatments in semi-closed cooling circuits and their impact on the quality of effluents discharged by CERN

Dissertação apresentada à Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, Gestão de Sistemas Ambientais

Water treatments in semi-closed cooling circuits and their impact on the quality of effluents discharged by CERN

Mestrado integrado em Engenharia do Ambiente, perfil: Gestão de Sistemas Ambientais

Células solares semi-transparentes de silício amorfo micro/nanocristalino

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia dos Materiais

Automated image tagging through tag propagation

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial Para obtenção do grau de Mestre em Engenharia Informática

Natural antioxidants extraction and their incorporation into model pharmaceutical systems

Dissertation to obtain a Master Degree in Biotechnology

Sistemas de protecção sísmica semi-activos aplicados em estruturas de engenharia civil caso de estudo: amortecedores com fluído magneto-reológico

Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Perfil Estruturas

Algorithms for information extraction and signal annotation on long-term biosignals using clustering techniques

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

O estudo de pavimentações regulares e semi-regulares com ambiente de geometria dinâmica

Dissertação para obtenção do Grau de Mestre em Ensino da Matemática

The influence of burden of care and perceived stigma on expressed emotions of relatives of stable persons with schizophrenia in Nigerian semi-urban/urban settings

RESUMO: Schizophrenia’s burden defines experience of family members and is associated with high level of distress. Courtesy stigma, a distress concept, worsens caregivers’ burden of care and impacts on schizophrenia. Expressed emotion (EE), another family variable, impacts on schizophrenia. However, relationship between EE, burden of care and stigma has been little explored in western literature but not in sub-Saharan Africa particularly Nigeria. This study explored the impact of burden of care and courtesy stigma on EE among caregivers of persons with schizophrenia in urban and semi-urban settings in Nigeria. Fifty caregivers each from semi-urban and urban areas completed a socio-demographic schedule, family questionnaire, burden interview schedule and perceived devaluation and discrimination scale. The caregivers had a mean age of 42 (± 15.6) years. Majority were females (57%), married (49%), from Yoruba ethnic group (68%), monogamous family (73%) and Christians (82%). A higher proportion of the whole sample (53%) had tertiary education. Three out of ten were sole caregivers. Seventy three (73%) lived with the person they cared for. The average number of hours spent per week by a caregiver with a person with schizophrenia was 35 hours. The urban sample had significantly higher proportion of carers with high global expressed emotion (72.7%) than the semi-urban sample (27.3%). The odds of a caregiver in an urban setting exhibiting high expressed emotion are 4.202 times higher than the odds of caregiver in a semi-urban setting. Additionally, there was significance difference between the urban and semi-urban caregivers in discrimination dimension. High levels of subjective and objective burden were associated with high levels of critical comments. In conclusion, this study is the first demonstration of urban-semi-urban difference in expressed emotion in an African country and its findings provide further support to hypothesized relationship between components of EE and burden of care.

Comparative effects of sediments contaminated by carcinogenic and non-carcinogenic PAHs in Dicentrarchus labrax: a semi-quantitative histopathological approach

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente

Valorization of pumpkin residue by supercritical extraction of added-value compounds

Dissertação para a obtenção do Grau de Mestre em Engenharia Química e Bioquímica