SmartClean: an incremental data cleaning tool

This paper presents the SmartClean tool. The purpose of this tool is to detect and correct the data quality problems (DQPs). Compared with existing tools, SmartClean has the following main advantage: the user does not need to specify the execution sequence of the data cleaning operations. For that, an execution sequence was developed. The problems are manipulated (i.e., detected and corrected) following that sequence. The sequence also supports the incremental execution of the operations. In this paper, the underlying architecture of the tool is presented and its components are described in detail. The tool's validity and, consequently, of the architecture is demonstrated through the presentation of a case study. Although SmartClean has cleaning capabilities in all other levels, in this paper are only described those related with the attribute value level.

IGTAI - an Idea Generation Tool for Ambient Inteligence

Today, business group decision making is an extremely important activity. A considerable number of applications and research have been made in the past years in order to increase the effectiveness of decision making process. In order to support the idea generation process, IGTAI (Idea Generation Tool for Ambient Intelligence) prototype was created. IGTAI is a Group Decision Support System designed to support any kind of meetings namely distributed, asynchronous or face to face. It aims at helping geographically distributed (or not) people and organizations in the idea generation task, by making use of pervasive hardware in a meeting room, expanding the meeting beyond the room walls by allowing a ubiquitous access through different kinds of equipment. This paper focus on the research made to build IGTAI prototype, its architecture and its main functionalities, namely the support given in the different phases of the idea generation meeting.

Residential property loans and performance during property price booms: evidence from European banks

Understanding the performance of banks is of the utmost relevance, because of the impact of this sector on economic growth and financial stability. Of all the different assets that make up a bank portfolio, the residential mortgage loans constitute one of its main. Using the dynamic panel data method, we analyse the influence of residential mortgage loans on bank profitability and risk, using a sample of 555 banks in the European Union (EU-15), over the period from 1995 to 2008. We find that banks with larger weights of residential mortgage loans show lower credit risk in good times. This result explains why banks rush to lend on property during booms due to the positive effects it has on credit risk. The results show further that credit risk and profitability are lower during the upturn in the residential property price cycle. The results also reveal the existence of a non-linear relationship (U-shaped marginal effect), as a function of bank’s risk, between profitability and the residential mortgage loans exposure. For those banks that have high credit risk, a large exposure of residential mortgage loans is associated with higher risk-adjusted profitability, through lower risk. For banks with a moderate/low credit risk, the effects of higher residential mortgage loan exposure on its risk-adjusted profitability are also positive or marginally positive.

Residential property loans and performance during property price booms: evidence from European

Understanding the performance of banks is of the u tmost importance due to the impact the sector may have on economic growth and financial stability. Residential mortgage loans constitute a large proportion of the portfolio of many banks and are one of the key assets in the determination of performance. Using a dynamic panel model , we analyse the impact of res idential mortgage loans on bank profitability and risk , based on a sample of 555 banks in the European Union ( EU - 15 ) , over the period from 1995 to 2008. We find that banks with larger weight s in residential mortgage loans display lower credit risk in good market conditions . This result may explain why banks rush to lend on property during b ooms due to the positive effect it has on credit risk . The results also show that credit risk and profitability are lower during the upturn in the residential property cy cle. Furthermore, t he results reveal the existence of a non - linear relationship ( U - shaped marginal effect), as a function of bank’s risk, between profitability and residential mortgage exposure . For those banks that have high er credit risk, a large exposur e to residential loans is associated with increased risk - adjusted profitability, through a reduction in risk. For banks with a moderate to low credit risk, the impact of higher exposure are also positive on risk - adjusted profitability.

QoS em WIMAX – Análise e avaliação de módulos para simulação com o ns-2

Mestrado em Engenharia Electrotécnica e de Computadores

Demand response in future power systems management – a conceptual framework and simulation tool

Mestrado em Engenharia Electrotécnica – Sistemas Eléctricos de Energia

Estudo e análise de soluções de acessos Wimax partilhados em cenários residenciais

Mestrado em Engenharia Electrotécnica e de Computadores

The evidence of conventional physiotherapeutic interventions after exercise-induced muscle damage: systematic review and meta-analysis

Abstract Introduction: Exhaustive and/or unaccustomed exercise, mainly those involving eccentric muscle actions, induces temporary muscle damage, evidenced by Delayed Onset Muscle Soreness. Different strategies to recover the signs and symptoms of this myogenic condition have been studied by researchers, as a result a significant number of articles on this issue have been published. Purpose: A systematic review was conducted to assess the evidence of the physiotherapeutic interventions of exercise-induced muscle damage. Methods: The electronic data bases were searched, including MEDLINE (1996-2011), CINHAL (1982- 2011), EMBASE (1988-2011), PEDro (1950-2011), and SPORTDiscus (1985-2011). Systematic review was limited to randomized control trials (RCTs) studies, written in English or Portuguese, which included physiotherapeutic interventions, namely massage, cryotherapy, stretching and low-intensity exercise, on adult human subjects (18-60 years old) of either gender. Studies were excluded when the intervention could not be assessed independently. The methodological quality of RCTs was independently assessed with the PEDro Scale by three reviewers. Results: Thirty-three studies were included in the systematic review; eight analyzed the effects of the massage, ten analyzed the effects of the cryotherapy, eight the effect of stretching and seventeen focused low-intensity exercise intervention. The results suggest that massage is the most effective intervention and that there is inconclusive evidence to support the use of cryotherapy; whereas the other conventional, namely stretching and low-intensity exercise, there is no evidence to prove their efficacy. Conclusion: The results allow the conclusion that massage is the physiotherapeutic intervention that demonstrated to be the most effective in the relief of symptoms and signs of exercise-induced muscle damage, as a result, massage should still be used in the muscular recovery after sports activities.

Geotecnia urbana da zona ribeirinha de Vila Nova de Gaia: criação de uma base de dados SIG geotécnica

O presente trabalho apresenta os resultados dos estudos geotécnicos e de uma base de dados da zona ribeirinha de Vila Nova de Gaia, com o objectivo de compreender melhor os aspectos geotécnicos em ambiente urbano numa área sensível com um registo histórico de instabilidade de taludes rochosos. Além disso, os escassos estudos científicos recentes de natureza geológica e geotécnica em Vila Nova de Gaia justificam o estudo exploratório da geotecnia urbana da zona ribeirinha de Vila Nova de Gaia. A importância de Vila Nova de Gaia como a terceira maior cidade portuguesa e como centro de intensa actividade económica e cultural despoleta uma constante necessidade de expansão. O aumento da densidade populacional acarreta a realização de projectos complexos de engenharia, utilizando o subsolo para a construção e, com frequência, em terrenos com características geotécnicas desfavoráveis. As cidades de Vila Nova de Gaia e do Porto foram sendo edificadas ao longo de encostas numa plataforma litoral caracterizada por uma vasta área aplanada, inclinando ligeiramente para Oeste. Esta plataforma foi cortada pelo Rio Douro num vale encaixado de vertentes abruptas, nas quais se localizam as zonas ribeirinhas das duas cidades. Este trabalho envolveu, inicialmente, uma caracterização topográfica, morfoestrutural, geotectónica e geomecânica da área de estudo e, numa fase posterior, o desenvolvimento duma base de dados geotécnica. Todos os dados geológicos e geotécnicos locais e os estudos geotécnicos levados a cabo in situ pelas diversas empresas e instituições foram representados cartograficamente numa base apoiada pelos Sistemas de Informação Geográfica (SIG). Esta metodologia inter‐disciplinar foi de grande valor para um melhor conhecimento dos riscos geológico‐geotécnicos ao longo das margens do Rio Douro. De facto, a cartografia geotécnica da zona ribeirinha de Vila Nova de Gaia deve constituir uma ferramenta importante para uma previsão mais rigorosa de futuras instabilidades de taludes e um bom instrumento para a gestão do espaço urbano.

Interface HL7 para observation patterns

Com a generalização das tecnologias de informação e comunicação na área da saúde, a monitorização remota de pacientes, a partir de dispositivos móveis, é uma realidade que contribui para uma melhor qualidade de vida dos pacientes. Mas, não são só os pacientes que ganham com a introdução destas tecnologias, também os profissionais de saúde e os hospitais retiram as suas vantagens. Os profissionais de saúde são munidos de uma ferramenta móvel de monitorização permanente de sinais vitais, aumentando desta forma a ligação médico-paciente. Relativamente aos hospitais, estes vêem os custos de manutenção reduzirem, em virtude da possibilidade dos pacientes puderem ser monitorizados a partir dos seus lares. Neste projecto pretende-se identificar mecanismos que possibilitem responder de forma eficaz à necessidade de partilha de informação, nomeadamente protocolos de comunicação, segurança e sistemas de integração. Foi projectado um protótipo, constituído por um middleware e uma aplicação cliente móvel, onde o middleware tem como missão garantir a interoperabilidade entre um servidor HL7 e a aplicação cliente, utilizada pelo profissional de saúde. A normalização da informação médica trocada entre o servidor HL7 e o middleware obedece à norma internacional HL7.

Visualização com nuvens de tags

Com a evolução da Internet houve uma consequente transformação da forma como os resultados são apresentados e das técnicas de visualização e apresentação de conteúdos. A presente dissertação é sobre visualização com nuvens de tags e foi a conjugação de diversos factores que originou a investigação sobre este tema. Uma nuvem de tags (em inglês: tag clouds) é uma concepção visual de um conjunto de tags isoladas com uma representação ilustrativa da sua importância, ou seja visualmente hierarquizadas e em que cada tag se hiperliga a um ou mais sítios Web ou documentos. São extremamente úteis para a navegação ou para a descoberta de informação genérica, podendo requerer menor carga cognitiva do utilizador durante consultas e pesquisas se alguns aspectos forem considerados na sua construção. Nesta dissertação discutem-se alguns dos factores visuais que podem contribuir para que as nuvens de tags sejam ferramentas efectivas e intuitivas para os utilizadores. O conceito de folksonomia está relacionado com nuvens de tags, permitindo categorizar as definições atribuídas a conteúdos recorrendo a palavras-chave (tags). Neste documento são ainda exploradas as suas vantagens e desvantagens. Discutem-se ainda alguns modos de visualização e apresentação de nuvens de tags, desde o tipo de ordenação ao algoritmo de geração da nuvem de tags. Aborda-se ainda o impacto do tipo de fonte e a utilização de cores monocromáticas ou coloridas que estas possam ter na visualização da nuvem. A própria tag também é categorizada e explorada ao nível do seu posicionamento na nuvem e a percepção que causa no utilizador. Sobre a visualização de nuvens de tags, refere-se ainda que as conclusões obtidas foram utilizadas num repositório de objectos educativos.

Ecotoxicity tests using the green algae chlorella vulgaris — a useful tool in hazardous effluents management

The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removedby chemical treatments.Areduction of ecotoxicitywas achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high level of ecotoxicity. For chloride determination wastewaters, an efficient reduction of chromium and silver was achieved after treatment. Regarding the reduction of ecotoxicity observed, EC50 increased from 0.059% to 0.5%, only a 0.02% concentration in the aquatic environment would guarantee no effects. Wastewaters containing phenanthroline/iron (II) complex were treated by chemical oxidation. Treatmentwas satisfactory concerning chemical parameters, although an increase in ecotoxicitywas observed (EC50 reduced from 0.31% to 0.21%). The wastes from the kinetic study of persulphate and iodide reaction were treated with sodium bisulphite until colour was removed. Although they did not reveal significant ecotoxicity, only over 1% of the untreated waste produced observable effects over algae. Therefore, ecotoxicity tests could be considered a useful tool not only in laboratory effluents treatment, as shown, but also in hazardous wastewaters management.

Fractional dynamics and MDS visualization of earthquake phenomena

This paper analyses earthquake data in the perspective of dynamical systems and fractional calculus (FC). This new standpoint uses Multidimensional Scaling (MDS) as a powerful clustering and visualization tool. FC extends the concepts of integrals and derivatives to non-integer and complex orders. MDS is a technique that produces spatial or geometric representations of complex objects, such that those objects that are perceived to be similar in some sense are placed on the MDS maps forming clusters. In this study, over three million seismic occurrences, covering the period from January 1, 1904 up to March 14, 2012 are analysed. The events are characterized by their magnitude and spatiotemporal distributions and are divided into fifty groups, according to the Flinn–Engdahl (F–E) seismic regions of Earth. Several correlation indices are proposed to quantify the similarities among regions. MDS maps are proven as an intuitive and useful visual representation of the complex relationships that are present among seismic events, which may not be perceived on traditional geographic maps. Therefore, MDS constitutes a valid alternative to classic visualization tools for understanding the global behaviour of earthquakes.

Mismatch negativity in childhood temporal lobe epilepsy: a proposed paradigm for testing central auditory processing

Background: Temporal lobe epilepsy (TLE) is a neurological disorder that directly affects cortical areas responsible for auditory processing. The resulting abnormalities can be assessed using event-related potentials (ERP), which have high temporal resolution. However, little is known about TLE in terms of dysfunction of early sensory memory encoding or possible correlations between EEGs, linguistic deficits, and seizures. Mismatch negativity (MMN) is an ERP component – elicited by introducing a deviant stimulus while the subject is attending to a repetitive behavioural task – which reflects pre-attentive sensory memory function and reflects neuronal auditory discrimination and perceptional accuracy. Hypothesis: We propose an MMN protocol for future clinical application and research based on the hypothesis that children with TLE may have abnormal MMN for speech and non-speech stimuli. The MMN can be elicited with a passive auditory oddball paradigm, and the abnormalities might be associated with the location and frequency of epileptic seizures. Significance: The suggested protocol might contribute to a better understanding of the neuropsychophysiological basis of MMN. We suggest that in TLE central sound representation may be decreased for speech and non-speech stimuli. Discussion: MMN arises from a difference to speech and non-speech stimuli across electrode sites. TLE in childhood might be a good model for studying topographic and functional auditory processing and its neurodevelopment, pointing to MMN as a possible clinical tool for prognosis, evaluation, follow-up, and rehabilitation for TLE.