Desenvolvimento de framework para análise e simulação dinâmica de sistemas elétricos de potência

Esta tese apresenta uma metodologia flexível orientada a objetos (OO) para a aplicação no projeto e implementação de sistemas de software utilizados na realização de estudos dinâmicos de sistemas elétricos de grande porte. A metodologia OO proposta objetiva tornar mais simples o desenvolvimento, a atualização e a manutenção de complexos sistemas de software para estudos de transitórios eletromecânicos em sistemas elétricos de potência. Os requisitos de usuário são mapeados para um conjunto de classes básicas, as quais são usadas para efetuar a modelagem de dispositivos dinâmicos tais como geradores elétricos. Para avaliação da metodologia foram realizados dois estudos de casos. No primeiro estudo caso o Framework foi aplicado na simulação das unidades geradoras da Usina Hidrelétrica de Tucuruí. Os resultados da simulação foram comparados com medições obtidos em ensaios no campo e mostrou a boa performance do Framework na reprodução dos fenômenos eletromecânicos desta usina de grande porte. No segundo estudo de caso, por outro lado, o Framework foi aplicado na modelagem de um sistema de geração fotovoltaico (PV) com seu sistema de Rastreamento da Potência Máxima (MPPT). O controle MPPT foi implementado usando técnicas digitais. Os resultados das simulações demonstram a performance do Framework na modelagem do sistema de controle de corrente, assim como no controle MPPT, dos sistemas de geração PV.

Colonoscopia virtual em cães

Pós-graduação em Medicina Veterinária - FMVZ

Desenvolvimento e construção de um fantoma homegêneo de mão para otimização de imagens radiográficas

Pós-graduação em Biologia Geral e Aplicada - IBB

Restauração de imagens utilizando projeções em conjuntos convexos e algoritmos evolucionistas

Pós-graduação em Ciência da Computação - IBILCE

Combinação de dispositivos de baixo custo para rastreamento de gestos

Pós-graduação em Ciência da Computação - IBILCE

Barroco paulista: novas possibilidades de documentação

Pós-graduação em Artes - IA

Valorizzazione di cartografia storica attraverso moderne tecniche geomatiche: recupero metrico, elaborazione e consultazione in ambiente digitale

“Cartographic heritage” is different from “cartographic history”. The second term refers to the study of the development of surveying and drawing techniques related to maps, through time, i.e. through different types of cultural environment which were background for the creation of maps. The first term concerns the whole amount of ancient maps, together with these different types of cultural environment, which the history has brought us and which we perceive as cultural values to be preserved and made available to many users (public, institutions, experts). Unfortunately, ancient maps often suffer preservation problems of their analog support, mostly due to aging. Today, metric recovery in digital form and digital processing of historical cartography allow preserving map heritage. Moreover, modern geomatic techniques give us new chances of using historical information, which would be unachievable on analog supports. In this PhD thesis, the whole digital processing of recovery and elaboration of ancient cartography is reported, with a special emphasis on the use of digital tools in preservation and elaboration of cartographic heritage. It is possible to divide the workflow into three main steps, that reflect the chapter structure of the thesis itself: • map acquisition: conversion of the ancient map support from analog to digital, by means of high resolution scanning or 3D surveying (digital photogrammetry or laser scanning techniques); this process must be performed carefully, with special instruments, in order to reduce deformation as much as possible; • map georeferencing: reproducing in the digital image the native metric content of the map, or even improving it by selecting a large number of still existing ground control points; this way it is possible to understand the projection features of the historical map, as well as to evaluate and represent the degree of deformation induced by the old type of cartographic transformation (that can be unknown to us), by surveying errors or by support deformation, usually all errors of too high value with respect to our standards; • data elaboration and management in a digital environment, by means of modern software tools: vectorization, giving the map a new and more attractive graphic view (for instance, by creating a 3D model), superimposing it on current base maps, comparing it to other maps, and finally inserting it in GIS or WebGIS environment as a specific layer. The study is supported by some case histories, each of them interesting from the point of view of one digital cartographic elaboration step at least. The ancient maps taken into account are the following ones: • three maps of the Po river delta, made at the end of the XVI century by a famous land-surveyor, Ottavio Fabri (he is single author in the first map, co-author with Gerolamo Pontara in the second map, co-author with Bonajuto Lorini and others in the third map), who wrote a methodological textbook where he explains a new topographical instrument, the squadra mobile (mobile square) invented and used by himself; today all maps are preserved in the State Archive of Venice; • the Ichnoscenografia of Bologna by Filippo de’ Gnudi, made in the 1702 and today preserved in the Archiginnasio Library of Bologna; it is a scenographic view of the city, captured in a bird’s eye flight, but also with an icnographic value, as the author himself declares; • the map of Bologna by the periti Gregorio Monari and Antonio Laghi, the first map of the city derived from a systematic survey, even though it was made only ten years later (1711–1712) than the map by de’ Gnudi; in this map the scenographic view was abandoned, in favor of a more correct representation by means of orthogonal projection; today the map is preserved in the State Archive of Bologna; • the Gregorian Cadastre of Bologna, made in 1831 and updated until 1927, now preserved in the State Archive of Bologna; it is composed by 140 maps and 12 brogliardi (register volumes). In particular, the three maps of the Po river delta and the Cadastre were studied with respect to their acquisition procedure. Moreover, the first maps were analyzed from the georeferencing point of view, and the Cadastre was analyzed with respect to a possible GIS insertion. Finally, the Ichnoscenografia was used to illustrate a possible application of digital elaboration, such as 3D modeling. Last but not least, we must not forget that the study of an ancient map should start, whenever possible, from the consultation of the precious original analogical document; analysis by means of current digital techniques allow us new research opportunities in a rich and modern multidisciplinary context.

Proceedings of the Institution of Electrical Engineers.

Vols.1-87,1872-1940 also called no.1-258.

A simple but efficient voice activity detection algorithm through Hilbert transform and dynamic threshold for speech pathologies

A simple but efficient voice activity detector based on the Hilbert transform and a dynamic threshold is presented to be used on the pre-processing of audio signals -- The algorithm to define the dynamic threshold is a modification of a convex combination found in literature -- This scheme allows the detection of prosodic and silence segments on a speech in presence of non-ideal conditions like a spectral overlapped noise -- The present work shows preliminary results over a database built with some political speech -- The tests were performed adding artificial noise to natural noises over the audio signals, and some algorithms are compared -- Results will be extrapolated to the field of adaptive filtering on monophonic signals and the analysis of speech pathologies on futures works

Photo-excess : two paradigms of archaeological photography

Discovering ‘photo-excess’: what difference does digital photography bring to the archaeological process, and does this difference constitute a paradigm shift from the traditional film model? Using reflexive practice, the contribution that digital photography has made to the archaeological process is explored. The themes presented in the photographs and exegesis combine visual exploration and original research to examine the role and place of archaeological photography in both a contemporary and an historical context. In contrasting the development of film-based photography of archaeology undertaken in the Eastern Mediterranean during the early 1900s with contemporary digital photography, this exegesis and creative work explores both the synergies and differences of the two photographic methods in archaeology. I introduce the term ‘photo-excess’ to describe the new role that digital photography plays in archaeological practice as compared to film, and demonstrate this difference through my creative work. At the turn of the 20th century, photography was affirmed as the major instrument for visual recording of an archaeological excavation. The combination of archaeological methods and photographic techniques from that era formed an approach to archaeological documentation and recording that was formalised by William Matthews Flinders Petrie in 1904. In this thesis I propose that Petrie became the father of modern archaeological photography through his work, and in recognition of his contribution I refer to his method as the ‘Petrie Paradigm’. Digital photography has made possible a quantum leap in the volume, quality and immediacy of visual data available to the user. Further, through the creative process, digital archaeological photography may provide visual information that exceeds the archaeologist’s original research questions, so that the digital image may sometimes exceed its primary role as a recording device. In such cases it may become the starting point for new research due to its potential photo-excess. I propose this as an emerging paradigm for archaeological photography.

L'adeguamento di tradizionali laboratori europei di restauro fotochimico alle tecniche digitali

La presente ricerca ha avuto come obbietivo studiare come stia avvenendo l'adattamento dei tradizionali laboratori fotochimici di film alle tecniche digitali attraverso l'analisi delle politiche di preservazione, del restauro, dei costi relativi all’acquisto di nuove apparecchiature e della migrazione ai nuovi media presso il British Film Institute (BFI), lo Svenska Filminstitutet (SFI), l’Eye Filmmuseum, L'Immagine Ritrovata e ANIM - Cinemateca Portuguesa. A questo scopo è stato utilizzato il metodo dello studio di caso, in cui sono state effettuate interviste con gestori e tecnici delle istituzioni citate al fine di rispondere al quesito della presente ricerca: quali sono l’impatto e le implicazioni di questo adattamento? Quali sono i risultati raggiunti con le nuove attrezzature e metodi di restauro e preservazione? Per arrivare a rispondere a queste domande lo studio è stato diviso in due sezioni. Nella prima parte, sono riportate le interviste svolte presso SFI, BFI, Eye e L'Immagine Ritrovata, realizzate al fine di ottenere dati che permettessero di formulare un'intervista più completa e approfondita. Successivamente, questa intervista più dettagliata è stata condotta con una sola istituzione, la Cinemateca Portuguesa. Pertanto, nella seconda parte dello studio di caso, sono state realizzate interviste a tecnici e dirigenti di ANIM - Cinemateca Portuguesa e dei suoi laboratori partner. L'analisi dei risultati comprende tutte le informazioni provenienti dalle cinque istituzioni intervistate. È stato notato che l'adattamento al digitale ha effettivamente apportato miglioramenti nella preservazione e nel recupero del materiale fotochimico, ma ciò ha anche fatto sorgere alcuni dilemmi nei laboratori. C'è apprensione per la scarsità di materiale della filiera fotochimica e per una sua ipotetica fine nel prossimo futuro, poiché non ci sono ancora sufficienti conoscenze sulla filiera digitale e sul comportamento di questi media con il passare del tempo. Gli intervistati hanno altresì dimostrato positività riguardo alle tecnologie digitali.

Proposal for underwater structural analysis using the techniques of ESPI and digital holography

The purpose of this article is to study the application of the holographic interferometry techniques in the structural analysis of submarine environment. These techniques are widely used today, with applications in many areas. Nevertheless, its application in submarine environments presents some challenges. The application of two techniques, electronic speckle pattern interferometry (ESPI) and digital holography, comparison of advantages and disadvantages of each of them is presented. A brief study is done on the influence of water properties and the optical effects due to suspended particles as well as possible solutions to minimize these problems. (C) 2009 Elsevier Ltd. All rights reserved.

Effect of power Doppler and digital subtraction techniques on the comparison of myocardial contrast echocardiography with SPECT

Objective-To compare the accuracy and feasibility of harmonic power Doppler and digitally subtracted colour coded grey scale imaging for the assessment of perfusion defect severity by single photon emission computed tomography (SPECT) in an unselected group of patients. Design-Cohort study. Setting-Regional cardiothoracic unit. Patients-49 patients (mean (SD) age 61 (11) years; 27 women, 22 men) with known or suspected coronary artery disease were studied with simultaneous myocardial contrast echo (MCE) and SPECT after standard dipyridamole stress. Main outcome measures-Regional myocardial perfusion by SPECT, performed with Tc-99m tetrafosmin, scored qualitatively and also quantitated as per cent maximum activity. Results-Normal perfusion was identified by SPECT in 225 of 270 segments (83%). Contrast echo images were interpretable in 92% of patients. The proportion of normal MCE by grey scale, subtracted, and power Doppler techniques were respectively 76%, 74%, and 88% (p < 0.05) at > 80% of maximum counts, compared with 65%, 69%, and 61% at < 60% of maximum counts. For each technique, specificity was lowest in the lateral wail, although power Doppler was the least affected. Grey scale and subtraction techniques were least accurate in the septal wall, but power Doppler showed particular problems in the apex. On a per patient analysis, the sensitivity was 67%, 75%, and 83% for detection of coronary artery disease using grey scale, colour coded, and power Doppler, respectively, with a significant difference between power Doppler and grey scale only (p < 0.05). Specificity was also the highest for power Doppler, at 55%, but not significantly different from subtracted colour coded images. Conclusions-Myocardial contrast echo using harmonic power Doppler has greater accuracy than with grey scale imaging and digital subtraction. However, power Doppler appears to be less sensitive for mild perfusion defects.