Derivation methods for hybrid knowledge bases with rules and ontologies

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia InformáticaFirst of all, I would like to thank my advisor, José Júlio Alferes, for his incredible support. Right from the start, during the first semester of this work, when we were 2700 km apart and meeting regularly via Skype, until the end of this dissertation, he was always committed and available for discussions, even when he had lots of other urgent things to do. A really special thanks to Terrance Swift, whom acted as an advisor, helping me a lot in the second implementation, and correcting all XSB’s and CDF’s bugs. This implementation wouldn’t surely have reached such a fruitful end without his support. I would also like to thank all my colleagues and friends at FCT for the great work environment and for not letting me take myself too serious. A special thanks to my colleagues from Dresden for encouraging me to work even when there were so many other interesting things to do as an Erasmus student. I’m indebted to Luís Leal, Bárbara Soares, Jorge Soares and Cecília Calado, who kindly accepted to read a preliminary version of this report and gave me their valuable comments. For giving me working conditions and a partial financial support, I acknowledge the Departamento de Informática of the Faculdade de Ciências e Tecnologias of Universidade Nova de Lisboa. Last, but definitely not least, I would like to thank my parents and all my family for their continuous encouragement and motivation. A special thanks to Bruno for his love, support and patience

Transactions in dynamic reactive environments

Most of today’s systems, especially when related to the Web or to multi-agent systems, are not standalone or independent, but are part of a greater ecosystem, where they need to interact with other entities, react to complex changes in the environment, and act both over its own knowledge base and on the external environment itself. Moreover, these systems are clearly not static, but are constantly evolving due to the execution of self updates or external actions. Whenever actions and updates are possible, the need to ensure properties regarding the outcome of performing such actions emerges. Originally purposed in the context of databases, transactions solve this problem by guaranteeing atomicity, consistency, isolation and durability of a special set of actions. However, current transaction solutions fail to guarantee such properties in dynamic environments, since they cannot combine transaction execution with reactive features, or with the execution of actions over domains that the system does not completely control (thus making rolling back a non-viable proposition). In this thesis, we investigate what and how transaction properties can be ensured over these dynamic environments. To achieve this goal, we provide logic-based solutions, based on Transaction Logic, to precisely model and execute transactions in such environments, and where knowledge bases can be defined by arbitrary logic theories.Fundação para a Ciência e a Tecnologia (FCT) - grant SFRH/BD/64038/2009, and conceived within project ERRO (PTDC/EIA-CCO/121823/2010

Síndrome metabólica e cirurgia bariátrica

Trabalho Complementar apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de licenciada em Ciências da NutriçãoA obesidade (OB) é uma doença caraterizada pela acumulação excessiva de gordura corporal e constitui um importante fator de risco para diversas comorbilidades. Entre estas, destaca-se hipertensão arterial (HTA), a dislipidemia e a resistência à insulina. A agregação destes fatores de risco permite definir um critério de síndrome metabólica (SM), a qual está associada a um aumento do risco de doença cardiovascular e de diabetes mellitus tipo 2 (DM2). A cirurgia de obesidade ou cirurgia bariátrica (CB) é uma das estratégias terapêuticas da OB ou da SM. Objetivo: O objetivo desta revisão da literatura é analisar o impacto que a CB tem na SM. Métodos: Foi realizada uma pesquisa bibliográfica sistemática na base de dados National Library of Medicine PUBMed-Medline, no período de março a junho de 2014, utilizando como palavras-chave os termos: “metabolic syndrome; bariatric surgery.” A pesquisa originou 210 artigos, tendo sido seleccionados 30 artigos. Resultados: A banda gástrica ajustável (BG) é o procedimento cirúrgico que conduz a uma perda de peso na ordem dos 25 a 30% nos primeiros 12 meses, após a cirurgia. Esta cirurgia não demonstrou ser a mais eficiente na diminuição da SM. A gastrectomia vertical (GV) mostrou uma perda de peso ligeiramente superior em comparação com a BG, entre 30 a 40% e uma melhoria dos parâmetros metabólicos. O grupo de derivação biliopâncreatica (DB) demonstrou uma melhoria da perda de peso na ordem dos 70 a 90%. O desvio (Bypass) gástrico em Y de Roux (DGYR) é uma técnica segura e estima-se uma perda de peso em 65%, num período de 12 meses. Este procedimento cirurgico leva a uma diminuição da prevalência da SM em 26% em 3 meses. Conclusão: Os resultados desta revisão sistemática permitem concluir que o grupo da DB são as melhores técnicas para tratar a obesidade mórbida, devido a uma maior perda de peso, como também na resolução da SM. No entanto, estas cirúrgias tem uma alta morbidade e por essa razão, o DGYR é um dos procedimentos mais populares. Esta também obtém bons resultados, ao nível da perda de peso e controlo da SM e pode ser uma escolha menos agressiva.Obesity (OB) is a disease characterized by excessive accumulation of body fat and is an important risk factor for several comorbidities. Among these, there is arterial hypertension (AH), dyslipidemia and insulin resistance. The aggregation of these risk factors can set a criterion of metabolic syndrome (MS), which is associated with an increased risk of cardiovascular disease and type 2 diabetes mellitus (T2DM). The obesity surgery or bariatric surgery (CB) is one of the therapeutic strategies of OB or SM. Objective: The objective of this literature review is to analyze the impact that the CB has the SM. Methods: A systematic literature search in the data base National Library of Medicine PubMed-Medline was conducted in the period March to June 2014, using as keywords the terms "metabolic syndrome; bariatric surgery". Search originated 210 articles, 30 articles were selected. Results: Adjustable gastric band is a surgical procedure that results in a weight loss in the range of 25 to 30% in the first 12 months after surgery. This surgery has not been shown to be more effective in decreasing the SM. Sleeve gastrectomy showed a slightly higher weight loss compared to the BG, between 30 and 40% and improved metabolic parameters. The biliopancreatic diversion group showed an improvement in the weight loss in the range of 70 to 90%. The gastric bypass surgery is a safe technique and it is estimated a weight loss of 65% over a period of 12 months. This surgical procedure leads to a decrease in the prevalence of MS in 26% in 3 months. Conclusion: The results of this systematic review support the conclusion that the group of DB are the best techniques to treat morbid obesity due to greater weight loss, but also in the resolution of MS. However, these surgeries has a high morbidity and therefore, the DGYR is one of the most popular procedures. This also get good results, in terms of weight loss and control of the MS and may be a less aggressive choice

A alienação escolar como fator preditor dos problemas de comportamento em alunos do 2º e 3º ciclo de escolaridade

Dissertação de mestrado em Psicologia da Educação, Desenvolvimento e Aconselhamento, apresentada à Faculdade de Psicologia e de Ciências da Educação da Universidade de CoimbraAo constructo de alienação está associado a falta de um sentimento de pertença, uma separação de quatro mundos: a família, os amigos, o trabalho e a escola (Bronfrenbrenner, 1986). A presente investigação procura perceber as características e expressões desta condição em contexto escolar, assumindo como objetivo principal o estudo da relação entre a alienação escolar e os problemas de comportamento, bem como a existência de um valor preditivo da alienação face a estes mesmos problemas. Para tal, recolheu-se uma amostra de 410 sujeitos (56.6% do sexo feminino e 43.4% do sexo masculino), entre os 10 e os 15 anos (M= 12.88; DP=1.44). O instrumento eleito para avaliar as dimensões da alienação face à escola foi a Escala de Alienação Escolar (EAE), e para a avaliação dos problemas de comportamento, de cariz externalizante e internalizante, utilizou-se o Questionário de Capacidades e Dificuldades (SDQ-Por), um instrumento de autorrelato que visa analisar a forma como o adolescente perceciona o seu comportamento. Os resultados obtidos sugeriram, uma associação entre a alienação escolar e os problemas de comportamento, particularmente com os de tipo externalizante. As variáveis sociodemográficas que mais parecem predizer esta relação são o sexo, com os rapazes a apresentar pontuações mais elevadas; a idade, com os adolescentes mais velhos (13-15 anos) a mostrarem-se mais propensos; e o nível socioeconómico, com adolescentes oriundos de um nível socioeconómico baixo e cujos pais se encontram desempregados a obter scores mais altos. Deixa-se em aberto para estudos futuros uma compreensão mais profunda da relação entre a alienação escolar e os problemas de cariz internalizante, visto que não se registaram associações estatisticamente significativas. Também o papel do comportamento pró-social enquanto variável protetora na expressão do problema levanta questões a explorar.The alienation construct is associated to a lack of belonging, a four world’s separation: family, friends, work and school (Bronfrenbrenner, 1986). This investigation aims to understand the characteristics and expressions of this condition in school context, assuming as main goal the study of the relation between school alienation and behavioral problems, as well as the existence of an alienation’s predictive value towards them. For that purpose, a sample of 410 subjects (56.6% female subjects and 43.4% male subjects), between ages 10 and 15 (M=12.88; SD=1.44). The selected instrument to evaluate alienation dimensions towards school was the School Alienation Scale (EAE). To evaluate externalizing and internalizing behavioral problems, the Strengths & Difficulties Questionnaire (SDQ) was used, a self-report instrument to analyse how the adolescent perceives his/her behavior. The obtained results do suggest an association between school alienation and behavioral problems, specially with the externalizing type. The sociodemographic variables which seems to better predict this relation are sex, with boys presenting higher scores; age, with the oldest teens (13-15 years) obtaining higher scores; and sociodemography, with adolescents coming from a low socioeconomic status and which parents are currently unemployed, obtaining higher scores. Future studies must attend in a deeper compreension of the relation between school alienation and externalizing behavioral problems, considering the inexistence of significative statistical associations. The role of prossocial behavior as a protective variable in the problem’s expression also brings questions to explore in future works

Matching CO2 large point sources and potential geological storage sites in mainland Portugal

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, Perfil Gestão e Sistemas AmbientaisFossil fuel combustion is the major source of the increasing atmospheric concentration of carbone dioxide (CO2) since the pre-industrial period. Combustion systems like power plants, cement, iron and steel production plants and refineries are the main stationary sources of CO2 emissions. The reduction of greenhouse gas emissions in one of the main climate change mitigation measures. Carbon dioxide capture and storage (CCS) is one of the possible mitigation measures. The objective of this study was to analyze the hypothesis for the implementation of CCS systems in mainland Portugal based on source-sink matching. The CO2 large point sources (LPS) considered in mainland Portugal were the largest installations included in the Phase II of the European Emissions Trading Scheme with the highest CO2 emissions, representing about 90% of the total CO2 emissions of the Trading Scheme, verified in 2007. The potential geological storage locations considered were the geological formations formerly identified in existing studies. After the mapping of LPS and potential geological sinks of mainland Portugal, an analysis based on the proximity of the sources and storage sites was performed. From this it was possible to conclude that a large number of LPS are within or near the potential storage areas. An attempt of estimating costs of implementing a CCS system in mainland Portugal was also performed, considering the identified LPS and storage areas. This cost estimate was a very rough exercise but can allow an order of magnitude of the costs of implementing a CCS system in mainland Portugal. Preliminary results suggest that at present CCS systems are not economically interesting in Portugal, but this may change with increasing costs of energy and emission permits. The present lack of information regarding geological storage sites is an important limitation for the assessment of implementing a CCS system in mainland Portugal. Further detailed studies are required, starting with the characterisation of geological sites and the candidate sources to CCS, from technical aspects to environmental and economical factors

Creating a product to segment donors and predict donor churn for the non-profit sector : the impact of paid social media advertising on financial revenue for non-profits

Thenon-profitsectorisdependentofspontaneousdonationsmadebyindividualandcompanies. Non-Governmental Organizations (NGOs) do not know how to leverage on data about their donors, which can have a direct effect on an organization’s success. In the present work, the team uses Machine Learning to segment donors and predict their churn probabilityusingdatafromaNGO,tohighlighttheimportanceoftargetedmarketingstrategies.Accordingly, the present study reflects on the advantages of paid advertising on social media in marketing campaigns, and their potential to positively affect the revenue of a non-governmental organization

Can we anticipate the stock market using the put-call parity? : a study on return predictability

Using the deviations from the put-call parity, we investigate the existence of relevant information about the future stock price not yet incorporated in the stock market. In order to capture the extent of the mispricing between pairs of calls and puts’ options, we calculate daily volatility spreads as the weighted average of the difference between implied volatilities. We use the option signals provided by our measure to create stock portfolios, assessing the informational flow between the two markets. We find a strong evidence that relatively expensive calls in respect to puts carry more information about future stock returns than the opposite: the hedge portfolio earns a four-week abnormal return of 31.6 bps. We further extend our research to study the effect of liquidity and informed trading. Our results suggest that the most liquid options are the ones conveying more information about future stock returns. Furthermore, informed trading is only relevant when its probability in the stock market assumes high values. Finally, we show an increase of returns’ predictability in the post-financial crisis period, which contradicts the argument present in literature that this flow would tend to disappear due to the learning process of the market participants. Overall, we provide evidence on return predictability by the incorporation in the stock market of information intrinsic to the deviations from put-call parity.Através dos desvios da paridade entre opções de compra e de venda, investigamos a existência de informação relevante sobre o preço futuro das ações, não incorporada no mercado de ações. De forma a quantificar o mispricing entre os dois tipos de opção, calculamos spreads de volatilidade definidos como a média ponderada da diferença entre as volatilidades implícitas pela opção de compra e de venda. Os diferentes níveis de indicadores revelados definem a criação de cada portfolio de ações, o que nos permitirá avaliar o fluxo de informação entre os dois mercados. Os resultados mostram que as opções de compra, sobrevalorizadas face às de venda, compreendem mais informação sobre os retornos futuros do mercado de ações do que o inverso: o hedge portfolio obtém um retorno anormal de 31.6 pp, após quatro semanas da sua formação. Numa extensão da análise, estudamos o efeito da liquidez e da existência de trading informado no mercado de ações. Os resultados sugerem que as opções mais líquidas são as que transmitem mais informação futura. Por outro lado, a existência de trading informado apenas se torna relevante quando a sua probabilidade assume valores elevados. Por último, verificamos um aumento na previsibilidade dos retornos no período após a crise financeira, o que não revela a aprendizagem dos participantes como referido na literatura. No geral, encontramos evidência da previsibilidade dos retornos através da incorporação, no mercado de ações, de informação intrínseca aos desvios da paridade entre opções de compra e de venda

Efficient Information Flows for University Departments: Towards Better Communication

The purpose of this study is to identify and evaluate the current processes of information management for communication in a university department with low human resources, with the objective of determining problems or improvement opportunities for the future. The research method for this study was through a systematic literature review of study cases similar to the one being discussed (in services type organizations and, if possible, at university organizations), identification of best practices for information management in low human resources cases and some qualitative methods like interviews with the department collaborator in charge of the activities in the process and observation of the processes in action at the department. Through the study of different process methodologies (for instance, Lean Sigma Six), it would be possible to model solutions and improvements that would allow several enhancements in the processes of information management and communication of the department. The final stage of the study will be the implementation of the solution (mentioned later in this dissertation) in the department to test the solutions and understand how effective they are for the department and the community that receives the information disseminated by the department and a discussion of those results, with the purpose of obtaining conclusions regarding the solutions results in comparison with what was ascertained in the literature review and state-of-the-art

The influence of politician appointments to corporate boards on the financial performance of firms in Portugal

Although several studies suggest that a corporate political activity such as the appointment of politicians enhances firm performance, the literature on this field is still conflicting and inconclusive. A study in the Portuguese economy may add some enlightening insights to the literature, helping to clarify this relationship. Therefore, drawing on the resource dependence theory which emphasizes how important it is for firms to minimize uncertainty and interdependence, I argue that politicians benefit firms by mitigating risks due to their knowledge and political influence. This thesis aims to evaluate the extent to which this relationship is true in the Portuguese context. Furthermore, this dissertation also compares firms from less and heavily regulated industries to better understand the impact of this moderator. Predictions were tested using a dataset of the 44 firms in the Euronext Lisbon Stock for the focal period of 2010 to 2018 to create a panel data with performance indicators and control variables. The results suggest a non-significant relationship between politicians and performance which might be associated with the double-effect a politician has by adding and destroying value at the same time. Nevertheless, a post hoc analysis demonstrates a strong effect of local politicians on performance, proving how valuable and powerful they are at a regional level. Moreover, I found robust evidence of a positive relationship between international politicians and performance under different levels of regulation which demonstrates the importance of reputation and legitimacy for a firm.Embora vários estudos sugiram que uma atividade política corporativa, como a nomeação de políticos, melhore o desempenho da empresa, a literatura sobre esse campo ainda é conflituosa e inconclusiva. Um estudo na economia portuguesa pode acrescentar algumas informações esclarecedoras à literatura, ajudando a esclarecer essa relação. Portanto, com base na teoria da dependência de recursos, que enfatiza a importância de as empresas minimizarem a incerteza e a interdependência, argumento que os políticos beneficiam as empresas mitigando os riscos devido ao seu conhecimento e influência política. Esta tese tem como objetivo avaliar até que ponto essa relação é verdadeira no contexto português. Além disso, esta dissertação também compara empresas de setores menos e fortemente regulados para entender melhor o impacto desse moderador. As previsões foram testadas usando um conjunto de dados das 44 empresas da Euronext Lisbon Stock para o período focal de 2010 a 2018 com o intuito de criar um painel de dados com indicadores de desempenho e variáveis de controle. Os resultados sugerem uma relação não significativa entre políticos e desempenho, que pode estar associada ao duplo efeito de um político, que podem adicionar e destruir valor ao mesmo tempo. No entanto, uma análise post hoc demonstra um forte efeito dos políticos locais no desempenho, provando o quão são valiosos e poderosos são, ao nível da cidade. Além disso, encontrei evidências robustas de uma relação positiva entre políticos internacionais e desempenho sob diferentes níveis de regulação, o que demonstra a importância da reputação e legitimidade para uma empresa