Adriane Parraga - Academia.edu (original) (raw)

Papers by Adriane Parraga

Olimpíada Nacional de Aplicativos (ONDA) is a scientific Olympiad for high school students from a... more Olimpíada Nacional de Aplicativos (ONDA) is a scientific Olympiad for high school students from all over Brazil. One of the problems highlighted in other scientific Olympiads, especially those in technological areas, is the disparity in the number of women participating, which are very low. The goal of this work is to present how the ONDA Olympics has solved this problem. In this way, ONDA is a different competition, as it provides integration into teams between boys and girls, where they discuss, present their ideas and their points of view, study about technologies and contemporary themes and develop creative application solutions for a better life in society. One of the requirements to participate in the competition is that the team contains one or more girls. The results analyzed based on the profile of the competition's participants demonstrate how inclusive is the ONDA and how it has served as an inspiration for more girls to participate.

This research presents a promoted study with female graduated of the Computer Engineering at UERG... more This research presents a promoted study with female graduated of the Computer Engineering at UERGS. The objective of this research was to investigate the academic path and the professional performance of the female graduated, seeking to identify difficulties and support networks throughout the course. The research is classified as applied and used the quali-quanti approach in data analysis. The results indicate that the female graduated are working in the professional area and that there is evidence that the research and extension projects in which they participated had an influence on their professions. In addition, a female support network within the course contributed to their permanence throughout the course. Resumo. Esta pesquisa apresenta um estudo realizado com as egressas do Curso de Engenharia de Computação da UERGS. O objetivo desta pesquisa foi investigar o percurso acadêmico e a atuação profissional das egressas, buscando identificar dificuldades e redes de apoio ao longo do curso. A pesquisa é classificada como aplicada e utilizou a abordagem quali-quanti na análise dos dados. Os resultados apontam que as egressas estão atuando na área profissional e que há evidências de que os projetos de pesquisa e extensão dos quais elas participaram tiveram influência em suas profissões. Além disso, uma rede de apoio feminina dentro da instituição contribuiu para a permanência das alunas ao longo do curso.

O Ministerio da Ciencia e Tecnologia (MCTI) promove anualmente a Semana Nacional de Ciencia e Tec... more O Ministerio da Ciencia e Tecnologia (MCTI) promove anualmente a Semana Nacional de Ciencia e Tecnologia (SNCT) com o objetivo de popularizar a ciencia. Neste ano o tema proposto e “Ciencia alimentando o Brasil” e a UERGS propoem discussoes sobre o mesmo, a fim de oferecer oportunidades de ampliacao do conhecimento para pesquisadores em inicio de carreira - alunos de pos-graduacao e graduacao – da instituicao e de outras Instituicoes de Ensino Superior (IES) do Estado. Os alunos do Mestrado Profissional em Ambiente e Sustentabilidade da UERGS irao participar deste momento discutindo temas sobre inovacao tecnologica. Durante a pre-organizacao do evento uma pesquisa de opiniao para professores e alunos da Universidade foi realizada, bem como uma investigacao com empresas regionais e palestrantes para que os temas mais pertinentes fossem selecionados. O evento ira ocorrer em Outubro de 2016, nas Unidades Porto Alegre e Novo Hamburgo e contara com palestras, aulas praticas, minicursos e oficinas. Pesquisadores da UERGS e de area da saude integrados a biotecnologia, engenheiros, e demais profissionais da energia, bioprocessos, inovacao e tecnologia serao palestrantes. O evento tambem ira contribuir com atividades nas areas de Educacao Cientifica e Tecnologica, tendo como objetivo dar continuidade as acoes da “III Semana Nacional da Ciencia e Tecnologia: Luz, Ciencia e Vida” (2015), aprimorando o planejamento e a execucao do evento, proporcionando aos organizadores adquirir competencias, conhecimento, experiencia para possibilitar o avanco das acoes da SNTC a cada ano. Projetos para CAPES e CNPq foram submetidos tendo avaliacao extremamente positiva. O CNPq reconheceu o merito mas nao disponibilizou recursos e a CAPES, por meio do edital PAEP n° 3/2016, disponibilizou o valor de R$8.250,00 Considerando o evento de 2015 esperamos que em 2016 tenhamos um publico maior ja que estamos investindo na divulgacao. O suporte da CAPES tambem ira possibilitar a acomodacao de palestrantes e participantes em um local adequado, com estrutura apropriada para o evento.

Advances in intelligent systems and computing, Nov 9, 2018

The use of Unmanned Aerial Vehicles (UAV) in precision agriculture (PA) has increased recently. M... more The use of Unmanned Aerial Vehicles (UAV) in precision agriculture (PA) has increased recently. Most applications capture images from cameras installed in the UAVs and later create mosaics for human inspection. In order to further improve the quality of data offered by this technology, application specific image processing algorithms that enhance, segment and extract information from the raw images delivering information equivalent to in-situ measurements are still missing. The present study describes a method for image segmentation to assist the characterization of nitrogen content in wheat fields. The proposed methodology uses the UAV and Computer Vision algorithms that process visual (RGB) and multispectral agricultural images. Data is first collected by the UAV that flies over an area of interest and collects high resolution RGB and multispectral images at a low altitude. Subsequently, a mosaic is created for each crop stage and the proposed algorithm segments the ROIs (regions where wheat crop is present) based on vegetation index. Using the proposed algorithm, the wheat plots are correctly segmented for two kinds of Brazilians wheat cultivates. The segmentation was validated by experts indicating that the proposed algorithm is suitable to be used as a first step of a method that assist the analyses of nitrogen content specific to wheat crops.

Acta Clinica Belgica (Multilingual Edition), 2008

Biomedical Signal Processing and Control, Sep 1, 2012

ABSTRACT In this paper we present a methodology to form an anatomical atlas based on the analysis... more ABSTRACT In this paper we present a methodology to form an anatomical atlas based on the analysis of dense deformation fields recovered by the Morphons non-rigid registration algorithm. The methodology is based on measuring the bending energy required to register the whole database to a reference, and the atlas is the one image in the database which yields the smallest bending energy when taken as reference. The suitability of our atlas is demonstrated in the context of head and neck radiotherapy through its application to a database with thirty-one computed tomography (CT) images of the head and neck region. In head and neck radiotherapy, CT is the most frequently used modality for the segmentation of organs at risk and clinical target volumes. One challenge brought by the use of CT images is the presence of important artifacts caused by dental implants. The presence of such artifacts hinders the use of intensity averages, thus severely limiting the application of most atlas building techniques described in the literature in this context. The results presented in the paper show that our bending energy model faithfully represents the shape variability of patients in the head and neck region; they also show its good performance in segmentation of volumes of interest in radiotherapy. Moreover, when compared to other atlases of similar performance in automatic segmentation, our atlas presents the desirable feature of not being blurred after intensity averaging.

Proceedings of SPIE, Mar 8, 2007

Intensity Modulated Radiotherapy is a new technique enabling the sculpting of the 3D radiation do... more Intensity Modulated Radiotherapy is a new technique enabling the sculpting of the 3D radiation dose. It enables to modulate the delivery of the dose inside the malignant areas and constrain the radiation plan for protecting important functional areas. It also raises the issues of adequacy and accuracy of the selection and delineation of the target volumes. The delineation in the patient image of the tumor volume is highly time-consuming and requires considerable expertise. In this paper we focus on atlas based automatic segmentation of head and neck patients and compare two non-rigid registration methods: B-Spline and Morphons. To assess the quality of each method, we took a set of four 3D CT patient's images previously segmented by a doctor with the organs at risk. After a preliminary affine registration, both non-rigid registration algorithms were applied to match the patient and atlas images. Each deformation field, resulted from the non-rigid deformation, was applied on the masks corresponding to segmented regions in the atlas. The atlas based segmentation masks were compared to manual segmentations performed by an expert. We conclude that Morphons has performed better for matching all structures being considered, improving in average 11% the segmentation.

International journal of applied earth observation and geoinformation, Mar 1, 2020

Several methods have been proposed to delineate management zones in agricultural fields, which ca... more Several methods have been proposed to delineate management zones in agricultural fields, which can guide interventions of the farmers to increase crop yield. In this study, we propose a new approach using remote sensing data to delineate management zones at three farm sites located in southern Brazil. The approach is based on the hypothesis that the measured aboveground biomass (AGB) of the cover crops is correlated with the measured cash-crop yield and can be estimated from surface reflectance and/or vegetation indices (VIs). Therefore, we used seven different statistical models to estimate AGB of three cover crops (forage turnip, white oats, and rye) in the season prior to cash-crop planting. Surface reflectance and VIs were used as predictors to test the performance of the models. They were obtained from high spatial and temporal resolution data of the PlanetScope (PS) constellation of satellites. From the time series of 30 images acquired in 2017, we used the PS data that matched the dates of the field campaigns to build the models. The results showed that the satellite AGB estimates of the cover crops at the date of maximum VI response at the beginning of the flowering stage were useful to delineate the management zones. The cover-crop AGB models that presented the highest coefficient of determination (R 2) and the lowest root mean square (RMSE) in the validation and test datasets were Support Vector Machine (SVM), Cubist (CUB) and Stochastic Gradient Boosting (SGB). For most models and cover crops, the Enhanced Vegetation Index (EVI) and the Normalized Difference Vegetation Index (NDVI) were the two most important AGB predictors. At the date of maximum VI at the beginning of the flowering stage, the correlation coefficients (r) between the cover-crop AGB and the cash-crop yield (soybean and maize) ranged from +0.70 for forage turnip to +0.78 for rye. The fuzzy unsupervised classification of the cover-crop AGB estimates delineated two management zones, which were spatially consistent with those obtained from cash-crop yield. The comparison between both maps produced overall accuracies that ranged from 61.20% to 68.25% with zone 2 having higher cover-crop AGB and cash-crop yield than zone 1 over the three sites. We conclude that satellite AGB estimates of cover crops can be used as a proxy for generating management zone maps in agricultural fields. These maps can be further refined in the field with any other type of method and data, whenever necessary.

Journal of Control, Automation and Electrical Systems, Apr 15, 2016

Analysis of limit-cycles in relay feedback systems is usually performed in continuous time, even ... more Analysis of limit-cycles in relay feedback systems is usually performed in continuous time, even though most such systems are implemented digitally. In this paper we discuss the limitations of the continuous time analysis, showing that even for standard plants with reasonable sampling rates its results can be considerably far from the truth. Then we present a discrete time analysis of relay feedback systems, providing analytical tools that overcome the limitations of their continuous time counterparts.

IFAC-PapersOnLine, 2018

Existing tuning formulas for PID based on relay feedback experiments are derived from continuous-... more Existing tuning formulas for PID based on relay feedback experiments are derived from continuous-time systems theory, even though most such systems are implemented digitally. These formulas rely on the fact that, according to this continuous time theory, the relay feedback experiment allows the identification of the ultimate point of the plant's frequency responsethe point at which its Nyquist plot crosses the negative real axis. We have shown in a recent paper (Bazanella and Parraga (2016)) that a sampled relay feedback experiment may exhibit various limit-cycles at possibly quite different frequencies, even for quite reasonable sampling rates-that is, well within the ranges recommended by sampling theory and control textbooks. In this paper we show the deleterious effect of this reality on the tuning of PID controllers and propose an improvement to the tuning formulas to overcome this limitation.

IEEE Transactions on Control Systems and Technology, Mar 1, 2017

The classical relay feedback method for tuning PID controllers can not be applied to plants whose... more The classical relay feedback method for tuning PID controllers can not be applied to plants whose Nyquist diagrams do not cross the negative real axis; these are customarily tuned based on the reaction curve experiment. In this paper we propose a tuning method based on a modified relay feedback experiment. In this experiment, a transfer function of constant phase in an arbitrarily large range of frequencies is inserted in the loop. The proposed methodology thus unifies the Ziegler-Nichols-like tuning methods, by allowing PID tuning based on relay feedback for a class of plants without ultimate frequency.

Brazilian Symposium on Computer Graphics and Image Processing, Oct 7, 2007

In this paper we present a methodology to build a computational anatomical atlas based on the ana... more In this paper we present a methodology to build a computational anatomical atlas based on the analysis of dense deformation fields recovered by the Morphons non-rigid registration algorithm. The anatomical atlas construction procedure is based on the minimization of the effort required to register the whole database to a reference. The suitability of our method is demonstrated for atlas construction of the head and neck anatomy. In this application, CT is the most frequently used modality for the segmentation of organs at risk and clinical target volume. One challenge brought by the use of CT images is the presence of important artefacts caused by dental implants. Such artefacts make the use of most atlas building techniques described in the literature impracticable in this context. The results have shown that our model is faithful for representing the shape variability presented in human nature with the advantage that our anatomical atlas does not have any degree of smoothness.

Brazilian Journal of Development, 2021

A evolução ocorrida no desenvolvimento dos VANT´s fez surgir alguns desafios, sendo que um deles ... more A evolução ocorrida no desenvolvimento dos VANT´s fez surgir alguns desafios, sendo que um deles está relacionado ao ambiente distribuído de suporte à aplicação. Esse artigo apresenta uma arquitetura distribuída para suporte à construção de sistemas baseados em

In this paper we compare three non-rigid registration methods for atlas-based segmentation: B-spl... more In this paper we compare three non-rigid registration methods for atlas-based segmentation: B-splines, morphons and a combination of morphons and demons. To assess the quality of each method, we use a data set of four patients, containing for each patient the computed tomography (CT) image and a manual segmentation of the organs at risk performed by an expert of the

IFAC-PapersOnLine, Jul 1, 2017

Abstract The identification of networks from measured data has been studied for many years in com... more Abstract The identification of networks from measured data has been studied for many years in computer science and statistics. Central to this topic is the identifiability of the network, also called reconstructibility or faithfulness in these communities. This paper examines a class of networks in which the node signals, assumed measurable, are connected by linear time-invariant transfer functions, and in which a noise signal and/or a known excitation signal may or may not be present at each node. The paper discusses the notion of network identifiability. It then proposes a definition that is shown to be efficient for the reconstruction of a dynamical network from measured data. This allows us to exhibit a parametrization of all equivalent network models that are consistent with the data, and thereby to produce a range of sufficient conditions for network identifiability. These conditions (in the form of prior knowledge on the structure of the excitations) show that for the identification of a dynamical network a trade-off exists between excitation from known external signals and excitation from the noise.

Much recent research has dealt with the identifiability of a dynamical network in which the node ... more Much recent research has dealt with the identifiability of a dynamical network in which the node signals are connected by causal linear time-invariant transfer functions and are possibly excited by known external excitation signals and/or unknown noise signals. So far all results on the identifiability of the whole network have assumed that all node signals are measured. Under this assumption, it has been shown that such networks are identifiable only if some prior knowledge is available about the structure of the network, in particular the structure of the excitation. In this paper we present the first results for the situation where not all node signals are measurable, under the assumptions that the topology of the network is known, that each node is excited by a known signal and that the nodes are noise-free. Using graph theoretical properties, we show that the transfer functions that can be identified depend essentially on the topology of the paths linking the corresponding vertices to the measured nodes. An important outcome of our research is that, under those assumptions, a network can often be identified using only a small subset of node measurements.

Tese de doutorado apresentada ao Programa de Pós-Graduação em Engenharia Elétrica da Universidade... more Tese de doutorado apresentada ao Programa de Pós-Graduação em Engenharia Elétrica da Universidade Federal do Rio Grande do Sul como parte dos requisitos para a obtenção do título de Doutor em Engenharia Elétrica.

MAVEBA, 2001

The aim of this work is to investigate quantitatively the capability of the Continuous Wavelet Tr... more The aim of this work is to investigate quantitatively the capability of the Continuous Wavelet Transform (CWT) as a tool to estimate (calculate) Jitter and Shimmer, assessing the error between these indices calculated in each Wavelet decomposition and the ones for the original signal, for several dilatation levels. Two synthetic vowels /a/ were generated with the fundamental frequencies of 120 Hz for male and 220 Hz for female, by an autoregressive 22 coefficient all-pole model, and Jitter and Shimmer were introduced to the signal using five different percentage variations. The signals were decomposed by CWT in eight levels of dilatation (1, 2, 4, 8, 16, 32, 64 and 128), using the Mexican Hat, Meyer and Morlet real bases. Jitter and Shimmer were calculated for the original signals and all eight levels of decompositions and then the errors between the indices in the decompositions and the original signals were calculated. It can be concluded that CWT can be used as a tool for pre-processing the signal to measure Shimmer preferentially, and Jitter, instead of using the original signal to do that. The Mexican Hat base provided the lowest errors for Shimmer analysis, where the best dilatation level was 8 (error below 0.1%). In addition, the errors associated with Shimmer index, in general, are lower than the ones associated with Jitter index.

Esta dissertação foi julgada adequada para a obtenção do título de Mestre em Engenharia e aprovad... more Esta dissertação foi julgada adequada para a obtenção do título de Mestre em Engenharia e aprovada em sua forma final pelo Orientador e pela Banca Examinadora.