379 research outputs found
Low-cost 3D LIDAR-based scanning system for small objects
Three-dimensional scanning is a task that is highly
important for our modern society and this is translated by a wide
area of knowledge that contains numerous approaches to this
task. As this process is non-trivial, most of the technologies are
expensive, with even the low-cost ones being a great investment
for the regular user. Therefore, this work presents a low-cost
LIDAR-based 3D scanning system that can perform 3D scans
of small objects and reconstruct their digital STL models. The
system consists of one rotating platform and a scanning arcshaped structure, which both are actuated by stepper motors.The project that gave rise to these results received the
support of a fellowship from ”la Caixa” Foundation (ID
100010434). The fellowship code is LCF/BQ/DI20/11780028.
This work also has been supported by FCT – Fundação para
a Ciência e Tecnologia within the Projects UIDB/50014/2020
and UIDB/05757/2020.info:eu-repo/semantics/publishedVersio
Optimal sensors positioning to detect forest fire ignitions
Forests have been harassed by fire in recent years. Whether by human action or for other reasons, the burned
area has increased harming fauna and flora. It is fundamental to detect an ignition early in order to firefighters
fight the fire minimizing the fire impacts. The proposed Forest Monitoring System aims at improving the
nature monitoring and to enhance the existing surveillance systems. A set of innovative operations is proposed
that will allow to identify a forest ignition and also will monitor the fauna. For that, a set of sensors are being
developed and placed in the forest to transmit data and identify forest fire ignition. This paper addresses a
methodology that identifies the ideal positions to place the developed sensors in order to minimize the fire
hazard. Some preliminary results are shown by a random algorithm that spread points to position sensor
modules in areas with high risk of fire hazard.This work has been supported by FCT — Fundação para a Ciência e Tecnologia within the Project Scope:
UIDB/5757/2020.info:eu-repo/semantics/publishedVersio
Three-dimensional scanning system based on a low-cost infrared sensor
Nowadays, with the availability of 3D printers, the
scanners for objects are becoming increasingly present since they
allow to replicate objects by 3D printing, especially for small scale
sizes. However, the majority of these technologies are expensive,
due to the complexity of this task. Therefore, this work presents
a prototype of a low-cost 3D scanning system for small objects
using a point cloud to stereolithography approach where it was
already validated in simulation in previous work. This concept
has a restriction that the objects must have a uniform shape,
i.e, without discontinuities. The architecture is composed of two
stepper motors, due to their precision, a rotating plate to allow
360 degrees scans and another rotating structure that allows the
infrared distance sensor to scan the object from bottom to top
(90 degrees). The prThis work has been supported by FCT - Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/05757/2020. The project that gave rise to these results received the support of a fellowship from ”la
Caixa” Foundation (ID 100010434). The fellowship code is LCF/BQ/DI20/11780028.info:eu-repo/semantics/publishedVersio
(Re)Formação docente em Contabilidade: uma reflexão sobre os programas de doutorado no Brasil
No presente trabalho problematizamos a formação docente em Contabilidade no Brasil, por meio da análise dos componentes curriculares voltados para o ensino e pesquisa dos cursos de doutorado da área de Ciências Contábeis. A coleta de dados foi realizada na plataforma Sucupira, considerando as seguintes informações da coleta CAPES de 2019 dos 15 cursos de doutorado existentes no país: objetivos do doutorado; linhas de pesquisa; projetos de pesquisa; disciplinas (formação para o ensino); disciplinas (formação para a pesquisa); e estágio docência. No tocante à formação voltada para o ensino, o cenário atual é preocupante, pois apresenta poucas mudanças em relação aos estudos anteriores, demonstrando poucas iniciativas para a formação pedagógica inicial, fazendo com que os docentes se autorresponsabilizem por seu desenvolvimento didático-pedagógico. Acerca da formação para a pesquisa, os resultados indicam uma formação pautada por disciplinas de caráter metodológico e métodos quantitativos, demonstrando uma formação voltada para o mainstream. A partir desses resultados, esperamos contribuir para a reflexão sobre a (re)formação docente nos programas de doutorado em Contabilidade no Brasil, em um momento de expansão e consolidação da área.In this paper, we analyze the faculty training in Brazilian Accounting doctoral programs, focusing on the curricular components' analysis of teaching and research courses. We gathered the data through the Sucupira platform, using the following information from the 2019 CAPES collection, considering the 15 doctoral courses in Accounting that exist in the country: doctoral course objectives; research lines; research projects; disciplines (training for teaching); disciplines (training for research); and teaching internships. Regarding teaching training, the current scenario is preoccupying because it presents few changes concerning previous studies. Our findings point to few initiatives for initial pedagogical training, forcing faculties to take responsibility for their own pedagogical development. As for research training, the results indicate training based on methodological and quantitative methods courses, demonstrating a mainstream-focused training. Based on these results, we hope to contribute to the reflection on faculty (re)training in Brazilian Accounting doctoral programs at a time of expansion and consolidation
Limitações dos licenciandos na participação em atividades de pesquisa sobre o ensino de Química em um curso de licenciatura
O presente trabalho apresenta os motivos para que licenciandos participem de atividades ofertadas pelo curso de Licenciatura em Química. A pesquisa foi desenvolvida no Campus José Aloísio de Campos da Universidade Federal de Sergipe. Buscamos identificar quais alunos participam deste tipo de atividade, as contribuições e limitações da realização da pesquisa em ensino de Química durante a formação inicial. A coleta de dados ocorreu durante a disciplina Pesquisa em Ensino de Química I no período 2012/1 através da aplicação de questionário. Observamos que a maioria dos licenciandos apresenta pouco envolvimento com o curs
ANÁLISE PROBABILÍSTICA DAS REAÇÕES NAS ESTACAS DE UM CAIS DE CONTÊINERES
Neste trabalho aplicou-se o método de simulações de Monte Carlo ao modelo estrutural de um cais de contêineres com o objetivo de verificar as distribuições de probabilidade das reações máximas da estrutura. Duas combinações de carregamentos externos atuantes foram apresentadas, ambas simulando condições reais de funcionamento do terminal portuário. Aos parâmetros de entrada das simulações ”“ ações externas devidas ao peso próprio, sobrecarga, forças de amarração e equipamentos ”“ foram atribuídas distribuições de probabilidade baseando-se na bibliografia ou em dados obtidos pelos autores. O modelo estrutural em elementos finitos e as simulações de Monte Carlo foram elaborados no software ANSYS®, em sua interface APDL Mechanical, enquanto que as análises estatísticas foram executadas com software Statistica®. Os resultados demonstram que, para as duas situações estudadas, assim como as ações externas mais significativas para os valores das reações, as forças e momentos de reações nas bases das estacas do cais considerado ajustam-se adequadamente a distribuições normais de probabilidade
Machine learning to identify olive-tree cultivars
The identification of olive-tree cultivars is a lengthy and expensive process, therefore, the proposed work presents a new strategy for identifying different cultivars of olive trees using their leaf and machine learning algorithms. In this initial case, four autochthonous cultivars of the Trás-os-Montes region in Portugal are identified (Cobrançosa, Madural, Negrinha e Verdeal). With the use of this type of algorithm, it is expected to replace the previous techniques, saving time and resources for farmers. Three different machine learning algorithms (Decision Tree, SVM, Random Forest) were also compared and the results show an overall accuracy rate of the best algorithm (Random Forest) of approximately 93%.This work was carried out under the Project “OleaChain: Competências para a sustentabilidade e inovação da cadeia de valor do olival tradicional no Norte Interior de Portugal” (NORTE06-3559-FSE-000188), an operation to hire highly qualified human resources, funded by NORTE 2020 through the European Social Fund (ESF). The authors are grateful to the Foundation for Science and Technology (FCT,Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CeDRI (UIDB/05757/2020 and UIDP/05757/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/acceptedVersio
Indoor environment monitoring in search of gas leakage by mobile robot
Inspection based on mobile autonomous robots can assume
an important role in many industries. Instead of having fixed sensors, the
concept of assembling the sensors on a mobile robot that performs the
scanning and inspection through a defined path is cheaper, configurable
and adaptable. This paper describes a mobile robot, equipped with several
gas sensors and a LIDAR device, that scans an established area by
following a trajectory based on way-points searching for gas leakage and
simultaneously avoid obstacles in the map. In other words, the robot
follows the trajectory while the gas concentration is under a defined
value and surrounding the obstacles. Otherwise, the autonomous robot
starts the leakage search based on a search algorithm that allows to find
the leakage position. The proposed methodology is verified in simulation
based on a model of the real robot. The search test performed in a
simulation environment allows to validate the proposed methodology.This work is financed by the ERDF - European Regional
Development Fund through the Operational Programme for Competitiveness and Internationalisation-
COMPETE 2020 Programme within project (POCI-01-0145-FEDER-
006961), and by National Funds through the FCT - Funda~ao para a Ciência e a
Tecnologia (Portuguese Foundation for Science and Technology) as part of project
UID/EEA/50014/2013.info:eu-repo/semantics/publishedVersio
Ação de prolil-leucil-gliclnamida (PLG) na via nigroestriatal do rato
In order to study the nigrostriatal pathway, we obtained the rotatory behavior model in male Wistar rats by electrolytic lesion of the left lateral hypothalamic region. Animals thus lesioned displayed rotations toward the same side of lesion when apomorphine was administered, a result in disagreement with what has been obtained in the model with 6-hydroxydopamine lesion. The administration of PLG alone was not followed by rotatory behavior but when the compound was administered in low doses (0.25 to 1mg/kg) simultaneously with apomorphine to animals previously submitted to REM sleep deprivation, a significant increase in the number of rotations was observed in comparison with controls and groups receiving higher doses of PLG. These results indicate that PLG may act as, a modulator on dopamine receptors in the striatum.No intuito de estudar a via nigroestriatal, produzimos uma lesão na região hipotalâmica lateral de ratos Wistar. Os animais passavam a apresentar comportamento rotatório para o mesmo lado da lesão. A administração isolada do PLG não induziu o comportamento rotatório. Entretanto, com doses baixas do composto, concomitantemente à administração de apomorfina em animais previamente submetidos à privação de sono REM, observou-se aumento no número de rotações auando comparado ao grupo controle e aos grupos aue receberam doses altas de PLG. Estes achados sugerem que o PLG age como um modulador sobre os receptores dopaminérgicos do estriado.Escola Paulista de Medicina Department of Neurology and Neurosurgery Division of Extrapyramidal Diseases InvestigationEscola Paulista de Medicina Department of Neurology and Neurosurgery Head of the Division - Division of Extrapyramidal Diseases InvestigationUNIFESP, EPM, Department of Neurology and Neurosurgery Division of Extrapyramidal Diseases InvestigationEscola Paulista de Medicina Department of Neurology and Neurosurgery Head of the Division - Division of Extrapyramidal Diseases InvestigationSciEL
Phenotypic diversity and symbiotic efficiency of Bradyrhizobium spp. strains from Amazonian soils
Este trabalho teve como objetivo avaliar a diversidade fenotípica e a eficiência simbiótica de estirpes de Bradyrhizobium, isoladas de solos da Amazônia, sob diferentes sistemas de uso da terra (monocultura, capoeira, pastagem, floresta e sistema agroflorestal). A análise dos perfis de proteína total de 46 estirpes, obtidos por eletroforese em gel de poliacrilamida (SDS-PAGE), mostrou grande diversidade, tendo formado 11 grupos com similaridade acima de 80%. Apenas um dos grupos continha a estirpe referência de B. elkanii: BR29, recomendada como inoculante para soja. Vinte e duas estirpes testadas em vasos de Leonard, com caupi (Vigna unguiculata (L.) Walp.), induziram à produção de matéria seca e ao acúmulo de nitrogênio, na parte aérea da planta, e à eficiência relativa superiores aos da testemunha (sem N e sem inoculação). Entre as estirpes testadas, 13 induziram à produção de matéria seca e à eficiência relativa similares às da testemunha nitrogenada (com N, sem inoculação); cinco estirpes induziram a acúmulo de N superior ao da testemunha nitrogenada. Essas populações nativas são constituídas por grande diversidade de estirpes, com eficiência simbiótica variável, algumas das quais podem ser recomendadas para testes de eficiência agronômica.This work aimed to evaluate the phenotypic diversity and symbiotic efficiency of Bradyrhizobium strains isolated from Amazonian soils, under different land use systems (crop, fallow, pasture, forest and agroforestry system). Total protein profiles obtained by polyacrylamide gel electrophoresis (SDS-PAGE) of 46 strains showed great diversity, while 11 groups presented similarity above 80%. One of these groups contained the reference strain of B. elkanii: BR29, recommended as soybean inoculant. Twenty-two strains, tested in Leonard jars for symbiotic efficiency with Vigna unguiculata (L.) Walp. (cowpea) produced shoot dry matter, N-content, and relative efficiency higher than the control (without N, with inoculation). Production of shoot dry matter and relative efficiency were induced by 13 strains in a way similar to the N-control (with N, without inoculation); five strains induced higher nitrogen content than N-control. Native populations comprise high diversity of strains with variable symbiotic efficiency, and some of them could be recommended for agronomic efficiency assays
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