Monte Carlo simulations for dosimetric verification in photon and electron beam radiotherapy

Dissertação para obtenção do Grau de Doutor em Engenharia Biomédica

A Logic and tool for local reasoning about security protocols

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

A behavioral analysis tool for models of software systems

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

Optimization of multi-stage amplifiers in deep-submicron CMOS using a distributed/parallel genetic algorithm

IEEE International Symposium on Circuits and Systems, pp. 724 – 727, Seattle, EUA

Including context in a routing algorithm for the internet of things

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

A lightweight distributed super peer election algorithm for unstructured dynamic P2P systems

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

Geodupa - a geography-driven partial membership algorithm

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

Constraint-based verification of imperative programs

work presented in the context of the European Master’s program in Computational Logic, as the partial requirement for obtaining Master of Science degree in Computational Logic

Algorithm for the Parkinson’s disease behavioural models characterization using a biosensor

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Verification of analog circuits in power-down mode

Dissertação para obtenção do Grau de Mestre em Engenharia Eletrotécnica e Computadores

Proposta de abordagem para gestão de ocorrências em Serviços de Sangue

RESUMO: A gestão de ocorrências, sendo um requisito, quer legal, ao nível da regulação, quer normativo, tal como surge na ISO 9001, é um componente crítico para garantir a melhoria contínua um Serviço de Sangue, dado ter como objetivo a satisfação contínua dos requisitos dos dadores e recetores. A gestão eficaz, mas com eficiência, depende, também da eficácia da abordagem para gestão de ocorrência, nomeadamente, através da geração de correções, ações corretivas e ações preventiva eficazes. Esta dissertação discute a relevância, propondo um modelo de abordagem de gestão da qualidade conforme com os requisitos da lei fundamental da regulação de Serviços de Sangue, DL 267/2007, e com a norma global para sistemas de gestão da qualidade, ISO 9001. Esta abordagem usada descreve as várias etapas para a gestão eficaz de ocorrências, desde o seu relato, à sua classificação, tratamento com medição e análise risco associado e verificação da eficácia das ações tomadas. A eficácia do modelo teórico proposto foi verificado através da sua passagem para algoritmo informático num software comercial. Foi evidenciado neste software o cumprimento dos requisitos da abordagem teórica, pelo que a aplicação informática está conforme com os requisitos estabelecidos num procedimento documentado. Foi evidenciado, também, a rastreabilidade dos dados ao longo e toda a metodologia. A utilização de uma ferramenta informática também acrescentou valor ao modelo teórico, dado o acesso a toda a informação ser mais célere e de fácil acesso, quando comparado com o uso em suporte de papel.---------ABSTRACT: The issues management is a law requirement intended for regulation of “Blood Banks” and a quality management global requirement from ISO 9001. It is a critical activity, intended to to ensure continuous improvement on “Blood Bank”. Its goal is the continuous satisfaction of blood donors and transfusion recipients. Effective management and efficiency also depend on the effectiveness of the management of occurrence approach, namely in successful corrections, corrective actions and preventive actions. This paper discusses the relevance and it proposes a model approach to quality management according to the requirements of the fundamental law of regulation of “Blood Bank”, DL 267/2007, and according to the global standard for quality management systems, ISO 9001. This approach describes the various steps for effective management of incidents, such as his account, its classification, measurement and treatment using risk analysis and verification of the effectiveness of actions taken. The efficiency of the proposed theoretical model was verified through its transition to a computer algorithm trading software. It was demonstrated in this software that the requirements of the theoretical approach has been fulfilled by the computer application, which complies with the requirements established in a documented procedure. It was also evident that traceability of data across the methodology. The use of a software tool also added value to the theoretical model due to the access to all information to be faster and more easily accessible, when compared to paper.

Diffusional kurtosis imaging using a fast heuristic constrained linear least squares algorithm: a plugin for OsiriX

Diffusion Kurtosis Imaging (DKI) is a fairly new magnetic resonance imag-ing (MRI) technique that tackles the non-gaussian motion of water in biological tissues by taking into account the restrictions imposed by tissue microstructure, which are not considered in Diffusion Tensor Imaging (DTI), where the water diffusion is considered purely gaussian. As a result DKI provides more accurate information on biological structures and is able to detect important abnormalities which are not visible in standard DTI analysis. This work regards the development of a tool for DKI computation to be implemented as an OsiriX plugin. Thus, as OsiriX runs under Mac OS X, the pro-gram is written in Objective-C and also makes use of Apple’s Cocoa framework. The whole program is developed in the Xcode integrated development environ-ment (IDE). The plugin implements a fast heuristic constrained linear least squares al-gorithm (CLLS-H) for estimating the diffusion and kurtosis tensors, and offers the user the possibility to choose which maps are to be generated for not only standard DTI quantities such as Mean Diffusion (MD), Radial Diffusion (RD), Axial Diffusion (AD) and Fractional Anisotropy (FA), but also DKI metrics, Mean Kurtosis (MK), Radial Kurtosis (RK) and Axial Kurtosis (AK).The plugin was subjected to both a qualitative and a semi-quantitative analysis which yielded convincing results. A more accurate validation pro-cess is still being developed, after which, and with some few minor adjust-ments the plugin shall become a valid option for DKI computation

Planning and verification of multipath routing protocols

Conventionally the problem of the best path in a network refers to the shortest path problem. However, for the vast majority of networks present nowadays this solution has some limitations which directly affect their proper functioning, as well as an inefficient use of their potentialities. Problems at the level of large networks where graphs of high complexity are commonly present as well as the appearing of new services and their respective requirements, are intrinsically related to the inability of this solution. In order to overcome the needs present in these networks, a new approach to the problem of the best path must be explored. One solution that has aroused more interest in the scientific community considers the use of multiple paths between two network nodes, where they can all now be considered as the best path between those nodes. Therefore, the routing will be discontinued only by minimizing one metric, where only one path between nodes is chosen, and shall be made by the selection of one of many paths, thereby allowing the use of a greater diversity of the present paths (obviously, if the network consents). The establishment of multi-path routing in a given network has several advantages for its operation. Its use may well improve the distribution of network traffic, improve recovery time to failure, or it can still offer a greater control of the network by its administrator. These factors still have greater relevance when networks have large dimensions, as well as when their constitution is of high complexity, such as the Internet, where multiple networks managed by different entities are interconnected. A large part of the growing need to use multipath protocols is associated to the routing made based on policies. Therefore, paths with different characteristics can be considered with equal level of preference, and thus be part of the solution for the best way problem. To perform multi-path routing using protocols based only on the destination address has some limitations but it is possible. Concepts of graph theory of algebraic structures can be used to describe how the routes are calculated and classified, enabling to model the routing problem. This thesis studies and analyzes multi-path routing protocols from the known literature and derives a new algebraic condition which allows the correct operation of these protocols without any network restriction. It also develops a range of software tools that allows the planning and the respective verification/validation of new protocols models according to the study made.

EDP - A new estimation algorithm

The aim of this work project is to analyze the current algorithm used by EDP to estimate their clients’ electrical energy consumptions, create a new algorithm and compare the advantages and disadvantages of both. This new algorithm is different from the current one as it incorporates some effects from temperature variations. The results of the comparison show that this new algorithm with temperature variables performed better than the same algorithm without temperature variables, although there is still potential for further improvements of the current algorithm, if the prediction model is estimated using a sample of daily data, which is the case of the current EDP algorithm.

Generalized Dasymetric Mapping Algorithm for Accessing Land-Use Change

Contém resumo