Acompanha: Produto educacional: Uma proposta para o ensino de estática no ensino médio a partir de uma midia digital / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente estudo teve como objetivo produzir uma mídia digital sobre o conteúdo de estática com diferentes recursos a serem utilizados pelo professor de física, bem como, aplicar e verificar o potencial pedagógico dessa mídia, ou dos recursos presentes nessa mídia, junto a uma turma da primeira série do ensino médio de uma instituição pública da cidade de Paiçandu, Paraná. A mídia digital produzida se pautou em diferentes recursos de ensino, tais como: vídeos, simuladores e atividades práticas. Esse trabalho foi norteado pelos pressupostos da pesquisa qualitativa e, para se coletar os dados utilizou-se questionários estruturados, diário de bordo e todo material produzido pelos alunos durante o desenvolvimento das atividades. A aplicação das atividades da mídia ocorreram em quatro intervenções, totalizando oito horas no terceiro trimestre do ano letivo de 2017. Após análise e interpretação dos dados, a partir de pressupostos da Análise Textual Discursiva de Moraes e Galiazzi (2011), os resultados apontaram para uma evolução dos alunos com relação aos conceitos de estática abordados, bem como, para uma mudança de postura por parte dos alunos, principalmente aqueles que se faziam menos interessados nas aulas de Física. / The objective of this study was to produce a digital media about the static content with different resources to be used by the physics teacher, as well as to apply and verify the pedagogical potential of this media, or the resources present in this media, together with a first grade of a high school in a public institution in the city of Paiçandu, Paraná. The digital media produced was based on different teaching resources, such as videos, simulators and practical activities. This work was guided by the assumptions of the qualitative research and to collect the data was used structured questionnaires, logbook and all material produced by the students during the development of activities. The application of media activities occurred in four interventions, totaling eight hours in the third quarter of the 2017 school year. After analyzing and interpreting the data, based on the assumptions of the Discursive Textual Analysis of Moraes and Galiazzi (2011), the results pointed to an evolution of the students regarding concepts of static approach, as well as for a change of posture on the part of the students, mainly those that became less interested in the classes of Physics.

L’analyse isogéométrique pour la résolution de problèmes de la mécanique du solide suscite de vifs intérêts depuis une dizaine d’année. En effet, cette méthode de discrétisation autorise la description exacte des géométries étudiées permettant ainsi de supprimer les erreurs dues à une mauvaise description du domaine spatial étudié. Cependant elle pose un problème théorique de propagation de raffinement lors de la localisation de maillage. Des méthodes pour contourner ce problème ont été proposée dans la littérature mais complexifient grandement la mise en œuvre de cette stratégie de résolution. Cette thèse propose une stratégie de raffinement localisé adaptatif en espace pour les problèmes de statique et en espace temps pour les problèmes de dynamique transitoire dans le cadre de l’analyse isogéométrique. Pour cela une méthode de localisation pour l’analyse isogéométrique en statique basée sur une résolution multigrille est tout d’abord développée pour des problèmes en deux dimensions. Elle présente l’avantage de contourner la problématique de propagation de raffinement de maillage due à l’analyse isogéométrique tout en étant plus simple à mettre en œuvre que les méthodes déjà existantes. De plus, l’utilisation de l’analyse isogéométrique permet de simplifier les procédures de raffinement lors de l’adaptation de maillage qui peuvent être complexes lors de l’utilisationd’éléments finis classiques. Une méthode de raffinement adaptatif espace temps basée sur une résolution multigrille est ensuite développée pour des problèmes en une dimension. Une étude sur la structure des opérateurs est proposée afin de choisir un intégrateur temporel adapté. Les performances de cette stratégies sont mises en évidence, puis une modification de la méthode de résolution est proposée afin de diminuer significativement les coûts de calculs associées à cette résolution. La méthode de raffinement adaptatif espace temps est appliquée à quelques exemples académiques afin de valider son bon comportement lors de la localisation. / Isogeometric analysis applied to structural mechanics problems is a topic of intense concerns for a decade. Indeed, an exact description of geometries studied is allowed by this discretization method suppressing errors due to a bad description of the spatial domain considered. However, a theoretical problem of refinement propagation appears during mesh localization. Local refinement methods for isogeometric analysis has been developed and implied a complexification of the implementation of such a resolution strategy. This PhD thesis expose a space adaptative refinement strategy for linear elastic problems and a space-time one for transient dynamic using isogeometric analysis. For this purpose, a localization method for isogeometric analysis based on a multigrid resolution is developed for 2D linear elastic problems. This method allow to circumvent mesh refinement propagation inherent to isogeometric analysis, and is easier to implement than existing methods. Moreover, the use of isogeometric analysis simplifies refinement procedures occuring during mesh adaptation and which can be really complex using classical finite element analysis. Then, a space-time adaptative refinement based on a multigrid resolution is developed for one dimensional in space problems. A study on operators structure is exposed in order to choose a well suited time integrator. This strategy's performances are highlighted, then an evolution of this method is set up in order to lower computational costs. The space-time adaptaptive refinement is applied to some academical examples to show it good behavior during localization.

Pendant les dernières décennies, le travail d'une partie toujours croissante de chercheurs qui s'occupent de robotique s'est focalisé sur un groupe spécifique de robots qui fait partie de la famille des manipulateurs parallèles: les robots à câbles. Malgré les nombreuses études que l'on a consacrées à ce sujet, ces robots présentent encore aujourd'hui plusieurs problématiques complètement ou partiellement irrésolues. En particulier l'étude de leur cinématique, qui se révèle déjà complexe pour les manipulateurs parallèles traditionnels, est rendu encore plus compliqué par la nature non linéaire des câbles qui peuvent seulement exercer des efforts de traction. Le travail présenté dans cette thèse concentre donc son attention sur l'étude de la cinématique des robots à câbles et sur la mise au point de techniques numériques capables d'aborder une partie des problématiques liées à cela. La plupart du travail se concentre sur l'élaboration d'un algorithme pour la résolution du problème géométrique direct pour n'importe quel manipulateur à câbles qui se fonde sur l'analyse par intervalles. Cette technique d'analyse permet non seulement de résoudre rapidement le problème mais également de garantir les résultats obtenus en cas d'erreurs d'élimination et d'arrondi et de prendre en considération les incertitudes éventuellement présentes dans le modèle du problème. Le code développé a été testé grâce à un petit prototype de manipulateur à câbles dont la réalisation, qui a eu lieu pendant le parcours de doctorat, est décrite à l'intérieur du mémoire en accord avec la phase de conception du projet et de simulation. / In the past two decades the work of a growing portion of researchers in robotics focused on a particular group of machines, belonging to the family of parallel manipulators: the cable robots. Although these robots share several theoretical elements with the better known parallel robots, they still present completely (or partly) unsolved issues. In particular, the study of their kinematic, already a difficult subject for conventional parallel manipulators, is further complicated by the non-linear nature of cables, which can transmit forces only when they are taut. The work presented in this thesis therefore focuses on the study of the kinematics of these robots and on the development of numerical techniques able to address some of the problems related to it. Most of the work is focused on the development of an interval-analysis-based procedure for the solution of the direct geometric problem (DGP) of a generic cable manipulator. This technique, as well as allowing for a rapid solution of the problem, also guarantees the results obtained against rounding and elimination errors and can take into account any uncertainties in the model of the problem. The developed code has been tested with the help of a small manipulator whose realization is described in this dissertation together with its design and simulation phases.

The object of this dissertation is to analyse a drilling process of an automatic horizontal boring machine the SVD2 for drilling of bearing holes. There were problems with vibrations during drilling process, causing an extreme noise and this dissertation solves them. First of all it was necessary to analyse the vibrations, to examine a machining process and measure machine dynamics and statics. Another task was to compare measured results with mathematical models and after their analysis to design structural and other solutions. The SVD2 machine was designed on the basis of a previous type the SVD. Its conversion to a new one was based on adding of six spindles. As a result a number of drilled bodies was increased from one to four, so a performance was increased four times. That is why there was an original intention to rebuilt the other two spindle machines. To leave the basical parts of the machine without any modification ( such as a reinforcement of a mount and adjusting of a bigger distance of a side linear spindle guideway and a cross linear guideway of a support for clamping devices), would be unsuitable solution, which was confirmed after a measurement and a following analysis.

This research work focuses on the reactive power compensation of the permanent magnet synchronous generator (PSG) in wind power plants. PSG feeds a fixed voltage dc grid through a rectifier bridge. In variable speed operation, the PSG will be able to build torque only in small speed range. This is due to the fixed magnet of the PSG. External reactive power compensation provides an attractive solution to overcome this problem. Different reactive power compensation configurations were examined. Statics synchronous series compensation and a shunt passive filter were chosen as a compensation method. Simulation and implementation of small wind power plant were performed. The wind power plant consists of the synchronous generator, inverter, rectifier, coupling transformers and shunt passive filter. The experimental results agree to the proposed theory and simulation results. / Der Schwerpunkt meiner Promotion ist die Blindleistungskompensation bei einem permanenterregten Synchrongenerator. Der Synchrongenerator speist das Gleichsspannungsnetz über ein Gleichrichter. In der Drehzahlvariablen Betriebsverhalten können Nachteile auftreten. Die Folge ist, dass bei konstanter Gleichspannung und fester Erregung durch die Permanenterregung nur ein sehr kleiner Drehzahlbereich mit vernünftiger Drehmomentausbeute bedienbar ist. Ein möglicher Ausweg wäre eine variable Kompensationsspannung. Verschiedene Kompensationsverfahren wurden untersucht. Ein Series Active Filter und ein Shunt Passive-Filter wurden als Blindleistungskompensation gewählt. Im Rahmen meiner Dissertation beschäftige ich mich mit dem Aufbau und der Simulation einer Windkraftanlage. Diese besteht aus einem permanenterregten Synchrongenerator, einem Wechselrichrter, einem Gleichrichter, drei Transformatoren und einem passiven Filter. Das Versuchsergebnis zeigt, dass die Theorie mit der Simulation übereinstimmt.

Utvecklingen av framtidens flerbostadshus ställer höga krav på en bjälklagslösnings tekniska egenskaper. Plattbärlagsbjälklaget som idag utgör det vanligaste förekommande bjälklagsvalet vid uppförandet av flerbostadshus kan ses som en lösning som kombinerar en god bärförmåga med stora möjligheter ur teknisk synpunkt. Målet med denna undersökning har varit att jämföra det traditionella plattbärlaget med en nyutvecklad bjälklagslösning baserad på produkten förspänt håldäcksbjälklag (HD/F). Jämförelsen har utgått från de aktuella kraven som enligt Boverkets byggregler (BBR) idag ställs på bjälklag och fokuserat på aspekter ur ljud, brand och fuktsynpunkt. Dessutom har jämförelsen beaktat de maximala spännvidder som respektive lösning kan dimensioneras för. Resultatet av de genomförda undersökningarna visade på att den nyutvecklade bjälklagslösningen är tillräckligt konkurrenskraftig för att i framtiden få ett större användande inom flerbostadshus. Medan plattbärlagets fördelar utmärker sig ur ljudsynpunkt möjliggör dock användandet av den nyutvecklade lösningen längre spännvidder och kortare torktider. / The development of apartment buildings puts high demands on the technical characteristics of floor systems. The lattice girder system which today represents the most commonly utilized floor system when building apartment buildings, is characterized by a good load-bearing ability along with great opportunities from a technical point of view. The aim of this analysis was to compare the traditional lattice girder system with a newly developed floor system based on hollow core slabs. The comparison is based on the current technical requirements set by Boverkets byggregler (BBR) and has its main focus on subjects related to sound, fire and moisture matters. The comparison has also accounted for the maximum spans which can be used for each solution respectively. The results of the investigation show that the newly developed floor system is competitive enough to be used in future apartment buildings. While the advantages of the lattice girder system are distinctive from a sound point of view, the utilization of the newly developed floor solution enables longer spans and shorter curing time.

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This dissertation aims at verifying methodology used for somatographic evaluation of the shape and statics of the spine. The potential of the methodology verified lies in increased objectivity of upright body posture evaluation and thereby contributes to the specification of preventative measures for postural defects, and their consequences. Under a cross-sectional pilot study, a non-invasive somatographic method-a diagnostic DPT-3 system designated for spine shape diagnostics-was used to examine selected biomechanical parameters (spinal curves and statics in the sagittal plane in the upright position) in a total of 508 probands. Of this, 326 were school-age children and 182 adults. Among the key parameters monitored were: Cl (depth of cervical lordosis); LI (depth of lumbar lordosis); the sagittal balance of Cl/Ll, and VThk (distance of the peak of the thoracic kyphosis from the ideal verticals-IV). A questionnaire was used to evaluate the level of movement activity in probands and the relation between the occurrence of painful back and headaches and the measurement of biomechanical parameters and movement activity. A total of 81.3 % of children and 94.5 % of adults were found to have deviations from the biomechanically ideal posture model, which signals a postural defect. The values of the Cl (p...

<p>  </p> <p>In order to comprehend complex and abstract phenomena, students must partake in the process of learning by integrating complex and invisible components without ever physically encountering or manipulating such components. Prior knowledge and experiences will influence the way students assimilate and model new experiences and knowledge. If prior knowledge possesses a degree of non-normative conceptions, students' understanding of abstract phenomena may diverge dramatically from accepted scientific explanations. Embodied cognition proposes that learning about natural phenomena can develop from information gained via interactions between the body and the physical environment. Multimodal experiences can shape students' conceptual understanding of abstract phenomena.</p> <p>Incorporating technology tools to explore science concepts is a trend utilized to give high-quality education. The use of physical and virtual manipulation tools in science instruction has favored the improvement of modeling science phenomena in general. Visuohaptic simulations are also learning manipulatives that blend physical and virtual manipulation affordances as a unison experience. </p> <p>The current dissertation proposed the implementation of a learning experience where students engage in experimentation with a visuo-haptic simulation to explore and model reaction forces on truss structures. The study examined undergraduate students’ conceptual understanding, graphical representations, and the modeling refinement process of reaction forces on truss structures before, during, and after engaging with visuo-haptic simulation on truss structures using different modalities. A design-based research methodology was implemented to design, explore, and refine a learning experience with a visuo-haptic simulation of truss structures through two research phases. The learning experience occurred as a laboratory activity in a statics course at a Midwest university.</p> <p>The first phase of this dissertation investigated students' conceptual understanding and graphical representations of reactive forces on a complex truss structure by interacting with a visuo-haptic simulation of truss structures. Students participated in two treatment groups: visuo-haptic exposure and visual-only exposure. The results of the first phase suggested that students that engaged with the visuo-haptic simulation using different modalities improved their conceptual understanding of truss structures significantly. Moreover, students exposed to haptic feedback significantly improved their graphical representations on tasks where the haptic feedback was involved. </p> <p>The second phase of the current dissertation examined students’ developing models of reactive forces on a truss structure before, during, and after engaging with a visuo-haptic simulation of truss structures. Students participated in two sequential treatment groups: visual to visuo-haptic and haptic to visuo-haptic. The quantitative results suggest that both treatment groups performed significantly better in their model representations after being exposed to the learning experience but show no difference across treatment groups. The qualitative results suggest that the visual to visuo-haptic group interpreted their experiences much more coherently, leading to a more sophisticated version of their model of reaction forces on truss structures. </p>

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