Projeto de estruturas de um edifício em betão armado com recurso ao programa de cálculo automático ETABS

Trabalho de Projeto para obtenção do grau de mestre em Engenharia Civil

Text classification using compression-based dissimilarity measures

Arguably, the most difficult task in text classification is to choose an appropriate set of features that allows machine learning algorithms to provide accurate classification. Most state-of-the-art techniques for this task involve careful feature engineering and a pre-processing stage, which may be too expensive in the emerging context of massive collections of electronic texts. In this paper, we propose efficient methods for text classification based on information-theoretic dissimilarity measures, which are used to define dissimilarity-based representations. These methods dispense with any feature design or engineering, by mapping texts into a feature space using universal dissimilarity measures; in this space, classical classifiers (e.g. nearest neighbor or support vector machines) can then be used. The reported experimental evaluation of the proposed methods, on sentiment polarity analysis and authorship attribution problems, reveals that it approximates, sometimes even outperforms previous state-of-the-art techniques, despite being much simpler, in the sense that they do not require any text pre-processing or feature engineering.

A toolbox for hyperspectral image analysis

This paper introduces a new toolbox for hyperspectral imagery, developed under the MATLAB environment. This toolbox provides easy access to different supervised and unsupervised classification methods. This new application is also versatile and fully dynamic since the user can embody their own methods, that can be reused and shared. This toolbox, while extends the potentiality of MATLAB environment, it also provides a user-friendly platform to assess the results of different methodologies. In this paper it is also presented, under the new application, a study of several different supervised and unsupervised classification methods on real hyperspectral data.

Multi-scale vegetation classification using earth observation data of the Sundarban mangrove forest, Bangladesh.

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Integration of forest fire management with SDI: user requirements.

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Algorithms for time series clustering applied to biomedical signals

Thesis submitted in the fulfillment of the requirements for the Degree of Master in Biomedical Engineering

Classificações geomecânicas mineiras para o dimensionamento de maciços rochosos: o aplicativo MGC-RocDesign|Calc

Este trabalho tem como objetivo destacar a importância da utilização de software de geoengenharia no estudo das classificações de maciços rochosos nas engenharias de minas e geotécnica. Esta investigação pretendeu demonstrar a importância das classificações geomecânicas e índices geológico‐geomecânicos, tais como a Rock Mass Rating (RMR), Rock Tunnelling Quality Index (Q‐system), Surface Rock Classification (SRC), Rock Quality Designation (RQD), Geological Strength Index (GSI) and Hydro‐Potential Value (HP). Para esse efeito foi criada e desenvolvida uma calculadora geomecânica – MGC‐RocDesign|CALC: ‘Mining Geomechanics Classification systems for rock engineering design (version beta)’ – para de certa forma tornar mais simples, rápido e preciso o estudo das classificações geomecânicas sem que seja necessário recorrer manualmente às fastidiosas tabelas das classificações. A MGC‐RocDesign|CALC foi criada e desenvolvida no programa de folha de cálculo Microsoft Excel™ em linguagem Visual Basic for Applications© proporcionando o ambiente de carregamento de dados mais apelativos para o utilizador. Foi ainda integrada neste aplicativo a Calculadora Geotech|CalcTools que resulta da fusão das bases de dados ScanGeoData|BGD e SchmidtData|UCS criadas por Fonseca et al. (2010). Toda a informação foi integrada numa base de dados dinâmica associada a uma plataforma cartográfica em Sistemas de Informação Geográfica. Apresenta‐se como caso de estudo um dos trechos subterrâneos do maciço rochoso da antiga mina de volfrâmio das Aveleiras/Tibães (Mosteiro de Tibães, Braga, NW de Portugal). Além disso, apresenta‐se uma proposta de zonamento geomecânico do maciço rochoso da antiga mina das Aveleiras/Tibães com o objetivo de apoiar o dimensionamento de maciços rochosos. Por fim, apresenta‐se uma reflexão em termos de aplicabilidade, das potencialidades e das limitações da Calculadora Geomecânica MGC‐RocDesign|CALC.

Recomendação de cuidados de saúde

Atualmente, os guias turísticos são constituídos por diversos módulos, nomeadamente, módulos de recomendação e de modelação do utilizador. Estes ajudam a adaptar melhor as recomendações dadas ao utilizador de acordo com as suas preferências. A necessidade de adaptar os guias turísticos às possíveis necessidades de saúde do utilizador, foi a motivação para a realização desta dissertação. Quando alguém visita um local desconhecido, considera normalmente as condições tanto de alojamento como de alimentação desse local. Contudo, se por algum motivo, necessita de cuidados de saúde, essa pessoa não se encontra preparada para isso. Assim, a recomendação de uma instituição de saúde direcionada para o turista é uma solução possível para o problema encontrado. Pretendeu-se desenvolver um módulo de recomendação híbrido no âmbito da prestação de informações relacionadas com as possíveis necessidades de saúde do turista, tendo em conta o seu perfil. Para a sua implementação seguiu-se a abordagem baseada em conteúdo e técnicas de classificação das instituições de saúde a recomendar ao utilizador. O protótipo desenvolvido foi testado com alguns utilizadores em termos de funcionalidades. Finalmente, pretende-se que o protótipo seja testado com mais utilizadores, possuidores de diversas características em termos de condições de mobilidade, historial clínico e necessidades. Estes testes irão permitir avaliar o protótipo ao nível da qualidade da recomendação prestada. Poder-se-á, assim, atingir o objetivo relativo à integração deste protótipo num sistema de recomendação de apoio ao turista utilizado pela Câmara Municipal do Porto.

Distributed Linear Precoding and User Selection in Coordinated Multicell Systems

In this manuscript we tackle the problem of semidistributed user selection with distributed linear precoding for sum rate maximization in multiuser multicell systems. A set of adjacent base stations (BS) form a cluster in order to perform coordinated transmission to cell-edge users, and coordination is carried out through a central processing unit (CU). However, the message exchange between BSs and the CU is limited to scheduling control signaling and no user data or channel state information (CSI) exchange is allowed. In the considered multicell coordinated approach, each BS has its own set of cell-edge users and transmits only to one intended user while interference to non-intended users at other BSs is suppressed by signal steering (precoding). We use two distributed linear precoding schemes, Distributed Zero Forcing (DZF) and Distributed Virtual Signalto-Interference-plus-Noise Ratio (DVSINR). Considering multiple users per cell and the backhaul limitations, the BSs rely on local CSI to solve the user selection problem. First we investigate how the signal-to-noise-ratio (SNR) regime and the number of antennas at the BSs impact the effective channel gain (the magnitude of the channels after precoding) and its relationship with multiuser diversity. Considering that user selection must be based on the type of implemented precoding, we develop metrics of compatibility (estimations of the effective channel gains) that can be computed from local CSI at each BS and reported to the CU for scheduling decisions. Based on such metrics, we design user selection algorithms that can find a set of users that potentially maximizes the sum rate. Numerical results show the effectiveness of the proposed metrics and algorithms for different configurations of users and antennas at the base stations.

Introducing numerical analysis tools in engineering: a Scilab user case in electronics course

Software tools in education became popular since the widespread of personal computers. Engineering courses lead the way in this development and these tools became almost a standard. Engineering graduates are familiar with numerical analysis tools but also with simulators (e.g. electronic circuits), computer assisted design tools and others, depending on the degree. One of the main problems with these tools is when and how to start use them so that they can be beneficial to students and not mere substitutes for potentially difficult calculations or design. In this paper a software tool to be used by first year students in electronics/electricity courses is presented. The growing acknowledgement and acceptance of open source software lead to the choice of an open source software tool – Scilab, which is a numerical analysis tool – to develop a toolbox. The toolbox was developed to be used as standalone or integrated in an e-learning platform. The e-learning platform used was Moodle. The first approach was to assess the mathematical skills necessary to solve all the problems related to electronics and electricity courses. Analysing the existing circuit simulators software tools, it is clear that even though they are very helpful by showing the end result they are not so effective in the process of the students studying and self learning since they show results but not intermediate steps which are crucial in problems that involve derivatives or integrals. Also, they are not very effective in obtaining graphical results that could be used to elaborate reports and for an overall better comprehension of the results. The developed tool was based on the numerical analysis software Scilab and is a toolbox that gives their users the opportunity to obtain the end results of a circuit analysis but also the expressions obtained when derivative and integrals calculations, plot signals, obtain vector diagrams, etc. The toolbox runs entirely in the Moodle web platform and provides the same results as the standalone application. The students can use the toolbox through the web platform (in computers where they don't have installation privileges) or in their personal computers by installing both the Scilab software and the toolbox. This approach was designed for first year students from all engineering degrees that have electronics/electricity courses in their curricula.

On the Sensor Classification Scheme of Robotic Manipulators

This paper analyzes the signals captured during impacts and vibrations of a mechanical manipulator. The Fourier Transform of eighteen different signals are calculated and approximated by trendlines based on a power law formula. A sensor classification scheme based on the frequency spectrum behavior is presented.

Towards a classification scheme for musical sounds

Signal Processing: Algorithms, Architectures, Arrangements, and Applications (SPA), 2013

Impact of RIFLE Classification in Liver Transplantation

Acute renal failure (ARF) is common after orthotopic liver transplantation (OLT). The aim of this study was to evaluate the prognostic value of RIFLE classification in the development of CKD, hemodialysis requirement, and mortality. Patients were categorized as risk (R), injury (I) or failure (F) according to renal function at day 1, 7 and 21. Final renal function was classified according to K/DIGO guidelines. We studied 708 OLT recipients, transplanted between September 1992 and March 2007; mean age 44 +/- 12.6 yr, mean follow-up 3.6 yr (28.8% > or = 5 yr). Renal dysfunction before OLT was known in 21.6%. According to the RIFLE classification, ARF occurred in 33.2%: 16.8% were R class, 8.5% I class and 7.9% F class. CKD developed in 45.6%, with stages 4 or 5d in 11.3%. Mortality for R, I and F classes were, respectively, 10.9%, 13.3% and 39.3%. Severity of ARF correlated with development of CKD: stage 3 was associated with all classes of ARF, stages 4 and 5d only with severe ARF. Hemodialysis requirement (23%) and mortality were only correlated with the most severe form of ARF (F class). In conclusion, RIFLE classification is a useful tool to stratify the severity of early ARF providing a prognostic indicator for the risk of CKD occurrence and death.

A framework for supporting knowledge representation – an ontological based approach

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