Navegando por Assunto "Modelagem"

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A modeling-based approach for dependability analysis of a constellation of satellites
(2024-02-28) Farias, Daniel Castro de; Andrade, Ermeson Carneiro de; http://lattes.cnpq.br/2466077615273972; http://lattes.cnpq.br/5992660907313176
Satellite constellations play critical roles across various sectors, encompassing communication, Earth observation, and space exploration. Ensuring the dependable operation of these constellations is of utmost importance. This paper introduces a dependability modeling approach using stochastic Petri nets to analyze satellite constellations. The primary focus is on improving operational efficiency through the assessment of availability, reliability, and maintainability. The approach helps satellite designers make informed decisions when selecting constellation configurations by assessing various dependability metrics. Using a global navigation satellite system as a case study, we conduct extensive numerical experiments to evaluate the feasibility of our approach. The results demonstrate quantitatively the significant impact of redundant components on both reliability and availability. They also illustrate how utilizing satellites in repair and operational orbits can influence these metrics and highlight the direct correlation between reliability and maintainability.
Estimativa de biomassa em povoamento clonal de Eucalyptus sob o manejo de talhadia aos 36 meses de idade
(2023-04-24) Silva, Jonatas Carlos da; Berger, Rute; Hakamada, Rodrigo Eiji; http://lattes.cnpq.br/4186459700983170; http://lattes.cnpq.br/5395827385005105; http://lattes.cnpq.br/0314188517416061
Studies on the quantification of individual stem biomass are fundamental to determining the productivity of planted forests, facilitating forest management and planning activities, especially in coppice systems, which can reduce costs by up to 60% compared to high forest management. The aim of this study is to establish the best statistical models for estimating aboveground and wood biomass production, as well as questioning the use of general equations and previous rotation for Eucalyptus clones. The research was carried out in Mogi Guaçu-SP. Biomass was collected from the destructive analysis of clones, with 0.3 kg of leaves collected from each third of the canopy and branches, and discs removed at DBH (0%, 25%, 50%, 75%, and 100% with a diameter of 5 cm) of the stem, based on the total height of the tree. In the field, all aboveground compartments were weighed separately to obtain the total wet weight, while in the laboratory, each compartment was dried in a forced ventilation oven at 65°C to obtain the dry weight. Through regression analysis, adjusted equations were obtained, using total biomass and wood biomass (Bi) as the dependent variable and DBH and total height (H) of the trees as the independent variables. The Schumacher-Hall model showed the best fit for all clones, with the highest adjusted R² and the smallest standard errors of estimate. Based on this model, a general equation for wood biomass of clones on the site was adjusted, however, individual equations for each clone showed higher precision in individual biomass estimates. The adjusted equation in the first rotation of the stand overestimated the individual biomass of three clones by 22% and showed greater dispersion in clones with lower survival. Based on the results obtained, individual biomass estimation equations should be adjusted taking into account the silvicultural system and genotypes.
Modelos, modelagens e analogias: uma revisão da literatura em cinco periódicos no período de 2007 a 2020
(2021-12-09) Porto, Shyrlana Souza; Lima, Analice de Almeida; http://lattes.cnpq.br/2273105974559580; http://lattes.cnpq.br/0949749320823271
Models, models and analogies: a literature review in five journals from 2007 to 2020 aims to provide a bibliographic survey in important Brazilian journals in this time frame. They are: Science and Education (Bauru), Experiences in Science Teaching, Investigations in Science Teaching, Brazilian Journal of Education and Magazine Debates in Chemistry Teaching, all classified as Qualis CAPES A or B, in order to analyze trends , in the literature, related to models, models and analogies in Science teaching. To achieve the objectives, the research field of each journal was searched and articles that addressed the themes of the work presented here were selected. The reading of the texts and screening of the subjects that were in the perspective of this research were carried out, and in the end there were 70 articles that were in line with this proposal. Regarding the first objective, categories were established in order to carry out the analysis and discussion. For the second objective, the articles were read and grouped according to the similarity of the topics covered. From the results obtained, it was possible to assess that in these 13 years analyzed there is a considerable number of articles in the chosen magazines, which shows that research in the line of models, models and analogies is being developed, with a small peak in 2011 and intensifying more from the year 2016. When compiling the analyzed articles, it was observed that they presented trends for the theme models, with 65.3%, followed by the theme analogies with 20% and modeling, with 14.7% of the works evaluated. A great emphasis was observed in the field research approach, carried out in schools and universities, for example, in research from the student's perspective and in relation to the chemistry contents covered, Atomic Models, Molecular Geometry, Chemical Kinetics, Isomerism and Solubility. Modeling-related research needs to reach the classroom, as well as studies aimed at other didactic teaching strategies as well. There are many works by researchers who were willing, studied, applied and published, but somehow this knowledge faces obstacles to reaching the students' reality.
Otimização da malha de elementos finitos via software Ansys em núcleo C contraventado por lintéis
(2021-03-04) Luz, Pedro Vítor Carvalho de Alencar; Mello, Weslley Imperiano Gomes de; http://lattes.cnpq.br/4789771132461158
The modeling of structures via Finite Elements is quite usual nowadays, in view of its importance, this research was developed in order to provide subsidies to the modeling of reinforced concrete columns in thin walls of C cores braced by horizontal lintels in X and Z over the modeling possibilities through the commercial software Ansys. This paper presents the initial procedures necessary for the insertion of the geometry in the program platform and a comparison between the 3 types of existing meshes, Hexahedral, Tetrahedral and Prismatic, demonstrating their respective convergences, through data and analysis in the specified cases, exhibiting an accuracy of 96.25% in the 1st Vibration Mode of the column with horizontal lintels, an error notwithstanding 5% in the column with lintels arranged in X and an error less than 2% in the column with lintels arranged in Z.
Realidade virtual auxiliando as artes visuais: aplicação na obra O quarto em Arles
(2019-05-27) Santos, Tiago Ramos dos; Laurentino, Auta Luciana; Ziegelmaier, Rafael Suarez; http://lattes.cnpq.br/3113779571841568; http://lattes.cnpq.br/3805752873099282; http://lattes.cnpq.br/7192202614342067
The objective of this work is to presented as a conclusion work in the Specialization in Arts and Technology of Federal University of Pernambuco (UFRPE), aims to discuss the use of Virtual Reality in works of art. In this case around the life and work of Vincent Van Gogh, Impressionist and Post-impressionist artist, who lived between the years of 1853 to 1888 in the city of Groot Zundert, Holland. This is an exploratory research with a qualitative approach. And it is divided into three phases. The first stage was carried out from a bibliographical and audiovisual research about the artist. Among his work we prioritize the piece "The room in Arles" as source of study. Then we brought information about the use and types of 3D modeling software, rendering and post-production processes, and definition and application about virtual reality. And finally, we brought the registration and application of all processes and information to create the three-dimensional environment in 360º, in order to be applied in a virtual environment. As a result, we produced a three-dimensional model of the environment in the 'Room in Arles', and consequently, a 360º image, which combined with the VR BOX glasses, simulates the user‟s sensation of immersion to this environment.