Dissertations / Theses on the topic 'Large scale 3D printing'
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Barducci, Federica. "3D printing: l’evoluzione della tecnologia nel settore costruzioni." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
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L’architettura nei suoi svariati settori di studio è sempre stata strettamente influenzata dalle innovazioni tecnologiche che ogni periodo storico ha presentato. All'inizio degli anni Ottanta questo sviluppo ha portato un salto da un approccio “analogico” ad approccio “digitale”.
La modellazione tridimensionale ha conquistato una posizione importante nel mondo dell’architettura, sia come sostegno nella progettazione e produzione di edifici ex-novo che nel supporto per l’analisi e gestione dei manufatti esistenti.
Lo sviluppo della modellazione tridimensionale ha trainato con se lo sviluppo di software dedicati, strumentazioni tecnologiche e tecnologie innovative sempre più accurate.
Solo recentemente è stato compiuto un cambio di direzione, un’evoluzione tale da permetterci la materializzazione, per di più rapida, dei modelli che prima erano solo visualizzabili tramite uno schermo di un computer.
La materializzazione rapida di tali modelli è nata con la comparsa delle prime tecniche di stampa tridimensionale o stampa 3D, tecnologia che sta riscuotendo un enorme successo e di conseguenza un notevole sviluppo in numerosi settori e discipline scientifiche, non solo nell’ambito dell’architettura.
Questa tecnologia permette di modificare il paradigma produttivo fornendo vantaggi significativi come la diminuzione degli sprechi, la produzione di oggetti unici a costi molto inferiori rispetto ai metodi tradizionali e la possibilità di produrre oggetti con geometrie interne precedentemente impossibili da realizzare.
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Kaya, Fuat Emre. "Applications of Additive Manufacturing in Construction and Historic Building Restoration/Rehabilitation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22784/.
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The term “Additive Manufacturing” is described as the layered production of parts from a 3D file. Over the past century, this technology has evolved from a complement tool for conventional product development into an independent production method. Whereas high technology industries such as aerospace and medicine were already embraced additive manufacturing, structural engineering and architecture are lagging. Additive manufacturing has the potential to revolutionize the construction and restoration of historic buildings, with foreseeable benefits including highly complex and efficient structures with the reduction in material use and wastage, streamlining and expedition of the design-build process, improved customization. However, there are also challenges and demands: a new way of thinking for design and verifications for stability and serviceability of printed elements, the cost, the need for well-educated engineers.
In this dissertation, the current state of additive manufacturing in construction and historic building restoration/rehabilitation is reviewed as a combination of qualitative and quantitative-based studies. The research aims to give confidence to additive manufacturing applicability in these fields and stimulate further research. The opportunities and challenges are discussed by analysing concrete, polymer, and metal-based processes and their applications of additive manufacturing in the construction sector. A review of structural and non-structural applications in restoration projects, possible future applications in terms of structural strengthening are analysed and opportunities and challenges are identified and discussed. Based on the literature review and experimental lab tests, the outcome was obtained as the tensile mechanical properties are adequate for structural engineering applications. However, further interdisciplinary research on additive manufacturing is necessary to build confidence in structural engineers and architects.
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Batlle, Subirós Elisabet. "Large-Scale Surface registration." Doctoral thesis, Universitat de Girona, 2008. http://hdl.handle.net/10803/7606.
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The first part of this work presents an accurate analysis of the most relevant 3D registration techniques, including initial pose estimation, pairwise registration and multiview registration strategies. A new classification has been proposed, based on both the applications and the approach of the methods that have been discussed.The main contribution of this thesis is the proposal of a new 3D multiview registration strategy. The proposed approach detects revisited regions obtaining cycles of views that are used to reduce the inaccuracies that may exist in the final model due to error propagation. The method takes advantage of both global and local information of the registration process, using graph theory techniques in order correlate multiple views and minimize the propagated error by registering the views in an optimal way. The proposed method has been tested using both synthetic and real data, in order to show and study its behavior and demonstrate its reliability.
La primera part d'aquest treball presenta una anàlisi acurada de les tècniques de registre 3D es rellevants, incloent tècniques d'estimació de la posició inicial, registre pairwise i registre entre múltiples vistes. S'ha proposat una nova classificació de les tècniques, depenent de les seves aplicacions i de l'estratègia utilitzada.
La contribució mes important d'aquesta tesi és la proposta d'un nou mètode de registre 3D utilitzant múltiples vistes. El mètode proposat detecta regions ja visitades prèviament, obtenint cicles de vistes que s'utilitzen per tal de reduir els desalineaments en el model final deguts principalment a la propagació de l'error durant el procés de registre. Aquest mètode utilitza tant informació global com local, correlacionant les vistes mitjançant tècniques de grafs que permeten minimitzar l'error propagat i registrar les vistes de forma òptima. El mètode proposat ha estat provat utilitzant dades sintètiques i reals, per tal de mostrar i analitzar el seu comportament i demostrar la seva eficàcia.
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Vidal, Luciano. "Large bone defects reconstruction by using vascularization and 3D printing." Thesis, Nantes, 2019. http://www.theses.fr/2019NANT1034.
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La reconstruction de grands défauts osseux d’origine traumatique ou tumorale constitue un défi pour les orthopédistes et les chirurgiens plasticiens. Cette thèse est divisée en trois chapitres. Le premier chapitre décrit les différentes options chirurgicales actuelles et propose de nouvelles technologies telles que l’impression 3D dans la régénération de grands défauts osseux. La technique de référence en matière de reconstruction osseuse est la greffe autologue à lambeau libre qui contient les cellules du patient, ses facteurs de croissance et un apport vasculaire mais induit une morbidité importante au site de prélèvement. Le deuxième chapitre évalue une approche expérimentale consistant à produire in situ un greffon osseux synthétique pré-vascularisé et à le greffer dans un second temps dans un défaut osseux de taille critique chez le lapin. Cette étude animale démontre l’intérêt de la vascularisation dans la régénération osseuse mais nécessite deux chirurgies. Le troisième chapitre vise à étudier la faisabilité de régénérer de grands défauts osseux en une seule étape chirurgicale en utilisant des biomatériaux en phosphate de calcium personnalisés et imprimés en 3D, avec ou sans vascularisation. Cette dernière étude démontre la faisabilité de la planification pré-chirurgicale et de la reconstruction de grands défauts osseux avec des biomatériaux anatomiques et l’apport d'une vascularisation axiale dans la régénération osseuse. En conclusion, ce travail permet de proposer une nouvelle approche en médecine régénérative, personnalisée et vascularisée, pour la reconstruction de grands défauts osseuxLarge bone defect reconstruction constitutes a challenge for orthopedists and plastic surgeons. This thesis is divided into three chapters. The first chapter gives a review of the current surgical options and future technologies such as 3D printing for regeneration of large bone defects. The gold standard technique for bone reconstruction is autologous free flap transplantation that contains patient’s own cells, growth factors and a vascularization bed but induces morbidity. The second chapter evaluates an experimental approach consisting of the in situ production of a pre-vascularized synthetic bone graft and its subsequent transplantation to a critical-sized bone defect in rabbits. This animal study demonstrated the benefit of pre-vascularization of synthetic bone grafts for regenerating large bone defects but still required two surgeries. The third chapter aimed to investigate the feasibility of regenerating large bone defects in one surgical step by using 3D-printed customized calcium phosphate scaffolds with or without vascularization. This pre-clinical study demonstrated the benefits of pre-surgical planning for reconstruction of large bone defects with 3Dprinted personalized scaffolds and axial vascularization. In conclusion, this works enables to propose a new approach in regenerative medicine with customized and vascularized for large bone defect reconstruction
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Chou, George Tao-Shun. "Large-scale 3D reconstruction : a triangulation-based approach." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86296.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (p. [153]-157).
by George Tao-Shun Chou.
Ph.D.
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Magaya, Tafadzwa A. "Additive manufacturing (3 D printing) : challenges and opportunities for large scale adoption." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111466.
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Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references.
3D printing (additive manufacturing) has been around for more than 30 years. A lot of technological progress has been made in that time, most recently with new innovations such as metal 3D printing. Although the technology seems to hold a lot of promise, the rate of adoption has not lived up to the hype. The aim of this thesis is to research what has stopped 3D printing from catching on faster? What factors are hindering large scale adoption for mass production? We apply the "Iterating to Insights" framework to analyze technology limitations, market dynamics, business models and industry structure and to develop strategic insights that are surprising yet compelling. Our end goal was to develop a set of insights that can be used by an investor in a 3D printing company to evaluate whether an application or market being pursued by a potential investment is worthwhile or not.
by Tafadzwa A. Magaya.
M.B.A.
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Marsh, Georgina E. "Utilising micron-scale 3D printing to investigate particulate interactions for respiratory applications." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/50247/.
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In order to achieve drug delivery via the respiratory route, an understanding of particulate interactions is of vital importance. For successful delivery to the distal airways, an aerodynamic diameter of less than 5 μm must be achieved. However, particles of this size presents a difficult formulation challenge, due to the inherent cohesiveness between particles and adhesion to the device, due to the high surface to volume ratio of such small particles, causing the particles to clump together. This tendency will thereby cause a reduction in dispersion, aerosolisation and device efficiency; for this reason dry powder inhalers (DPIs) invariably fail to achieve a fine particle fraction efficiency above 15%. There are a wide variety of factors which affect particulate interactions including; surface roughness, surface chemistry, particle size or shape and particle mechanical properties. However, these factors are highly interrelated and so previous attempts to investigate their effect on particle adhesion generally have difficulty isolating the impact of each factor. For instance, investigating the effect of morphology on particulate interactions invariably utilise destructive techniques to alter the roughness, which is likely to alter other factors like surface energy and provide limited control for optimisation. With the rise of 3D printing (additive manufacturing) there is now the capability to produce sub- micron morphologies, and so a bottom-up approach to studying the effect of morphology on particulate interactions can be achieved. The aims of this thesis are therefore twofold. Firstly, to identify, optimise and evaluate a suitable additive manufacturing technique to produce well-defined micron scale morphologies appropriate for furthering the understanding of the importance of morphology on particle adhesion. This is a scale which is at least two orders of magnitude improvement on current state of the art 3D inkjet printers. Secondly, to measure the effect on particle adhesion and deposition to these morphologies, both on an individual particle and on a bulk powder basis, allowing elucidation and understanding of the effect of surface roughness on particle adhesion, with a specific focus on respiratory drug delivery. Printing well defined geometries of an appropriate micron scale size range for particle adhesion testing has been achieved, using two photon polymerisation (TPP). TPP is a novel 3D printing technique which as its name suggests involves the curing of usually acrylate containing polymer resins by the absorption of two infra-red photons in the focus of the laser beam. TPP has been shown to produce a sub-diffraction limit lateral resolution of 120 nm. By optimising the printer parameters and experimentation with differing structure fill and input settings the creation of a well- defined curve on a micron scale was achieved. The initial test morphologies comprised of a ridge with a semi-circular top with a diameter of 1 μm, which were shown to be reproducibly printed. These morphologies were then varied in a controllable fashion with varying ridge height and spacing between the ridges. A uniform and consistent surface chemistry was created using a plasma polymerised hexane (ppHex) coating. In order to evaluate particulate interactions relevant to pulmonary drug delivery both an understanding of the effect of morphology on both individual particle adhesion and bulk powder deposition in a fluid environment is needed. Individual particle-surface adhesion was achieved by testing the TPP structures against three particle types using single particle colloidal probe microscopy (polystyrene beads diameter 10 μm and 5 μm and a lactose particle designed for inhalation formulations). The analysis of this data provides evidence of a clear trend between particle contact area and adhesion recorded both on the ppHex control and the TPP coated morphologies. The TPP morphologies are shown to locally reduce the overall adhesion, in comparison to the flat substrate. The ridge height is also seen to have a significant effect on particle adhesion, with 5 μm < 3 μm < 1 μm for the polystyrene beads, but 3 μm < 5 μm < 1 μm for the Respitose SV003 lactose particle for all ridge spacings. Varying the ridge spacing produced two differing trends in adhesion to the polystyrene beads. If the particle was unable to penetrate the valleys of the roughness, for the 1 μm high ridges, a significant effect on particle adhesion was seen with 3 μm < 1 μm for the polystyrene beads. In contrast, the 3 μm and 5 μm high ridges showed the opposite trend when the particle is unable to descend between the ridges with 1 μm < 3 μm < 8 μm for the polystyrene beads. Investigation of the bulk powder deposition of the particles on the TPP structures and any subsequent re-entrainment in a fluid environment was then achieved using a novel methodology developed during the course of this work. This combines the use of a standard next generation impactor, which generally is used to separate out a respiratory formulation based on aerodynamic diameter, with the TPP substrates. This shows that ridge height has a significant effect on particle adhesion with 3 μm < 1 μm < 5 μm. In contrast, the different spacings of the ridges were not shown to produce a significant difference in particle deposition. This is likely due to the conflicting effect of asperity spacing on the processes of particle deposition and re-entrainment. This thesis therefore highlights the capability of TPP, to produce well-defined micron scale structures with varying morphologies. It then shows that these can be successfully utilised to provide valuable insight into the effect of surface morphology on particle- surface interactions, specifically; adhesion, deposition and re-entrainment.
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Pietrok, Jack. "Real-Time Stylized Rendering for Large-Scale 3D Scenes." DigitalCommons@CalPoly, 2021. https://digitalcommons.calpoly.edu/theses/2331.
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While modern digital entertainment has seen a major shift toward photorealism in animation, there is still significant demand for stylized rendering tools. Stylized, or non-photorealistic rendering (NPR), applications generally sacrifice physical accuracy for artistic or functional visual output. Oftentimes, NPR applications focus on extracting specific features from a 3D environment and highlighting them in a unique manner. One application of interest involves recreating 2D hand-drawn art styles in a 3D-modeled environment. This task poses challenges in the form of spatial coherence, feature extraction, and stroke line rendering. Previous research on this topic has also struggled to overcome specific performance bottlenecks, which have limited use of this technology in real-time applications. Specifically, many stylized rendering techniques have difficulty operating on large-scale scenes, such as open-world terrain environments. In this paper, we describe various novel rendering techniques for mimicking hand-drawn art styles in a large-scale 3D environment, including modifications to existing methods for stroke rendering and hatch-line texturing. Our system focuses on providing various complex styles while maintaining real-time performance, to maximize user-interactability. Our results demonstrate improved performance over existing real-time methods, and offer a few unique style options for users, though the system still suffers from some visual inconsistencies.
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Booth, James. "The construction and application of large scale 3D facial models." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/62330.
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3D Morphable Models (3DMMs) are powerful statistical models of the 3D shape and texture of the human face, and algorithms based around them are presently state of the art for recovering the 3D geometry and appearance of a face from an image. Even so, the applications of such techniques are gated by a number of factors. Firstly, existing techniques for constructing 3DMMs require manual intervention, limiting the amount of training data that can be used. As 3DMM algorithms can only recover solutions present in the span of the statistical model used, this places a fundamental limit on reconstruction quality to the confines of face models trained from smaller cohorts of data. Secondly, existing approaches for 3D reconstruction from images using 3DMMs are either fragile to real-world "in-the-wild" image effects, or limited in their ability to recover person-specific detail. Finally, there is limited work on the recovery of 3D geometry from "in-the-wild" video sequences of an individual, a very common modality of data in 2017. This thesis takes steps forwards in all three of these domains. A novel pipeline for 3DMM construction is presented that is completely automated, allowing for the construction of large scale 3D Morphable Models for the first time. By using this approach on a new dataset of 10,000 facial scans, the Large Scale Facial Model (LSFM) is introduced, a new 3DMM which is shown to have far more representative power than previous facial models. It is demonstrated that this increased power translates into better performance in 3DMM applications, and a study is performed into the effects of demographic traits such as age, gender and ethnicity on 3D facial appearance. A new approach for fitting 3DMMs to images is developed which is capable of recovering shape detail without sacrificing robustness to "in-the-wild" effects. To achieve this, it is demonstrated that an "in-the-wild" texture model for a 3DMM can be learnt from a distribution of real world images. This new "in-the-wild" 3DMM benefits from a simple but effective cost function that can be reliably optimised even in the case of challenging facial images. Finally, videos of people are given specific treatment for the "in-the-wild" 3DMM, leading to an optimal solution for 3D face tracking in this common data modality.
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Wang, Chen. "Large-scale 3D environmental modelling and visualisation for flood hazard warning." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/3350.
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3D environment reconstruction has received great interest in recent years in areas such as city planning, virtual tourism and flood hazard warning. With the rapid development of computer technologies, it has become possible and necessary to develop new methodologies and techniques for real time simulation for virtual environments applications. This thesis proposes a novel dynamic simulation scheme for flood hazard warning. The work consists of three main parts: digital terrain modelling; 3D environmental reconstruction and system development; flood simulation models. The digital terrain model is constructed using real world measurement data of GIS, in terms of digital elevation data and satellite image data. An NTSP algorithm is proposed for very large data assessing, terrain modelling and visualisation. A pyramidal data arrangement structure is used for dealing with the requirements of terrain details with different resolutions. The 3D environmental reconstruction system is made up of environmental image segmentation for object identification, a new shape match method and an intelligent reconstruction system. The active contours-based multi-resolution vector-valued framework and the multi-seed region growing method are both used for extracting necessary objects from images. The shape match method is used with a template in the spatial domain for a 3D detailed small scale urban environment reconstruction. The intelligent reconstruction system is designed to recreate the whole model based on specific features of objects for large scale environment reconstruction. This study then proposes a new flood simulation scheme which is an important application of the 3D environmental reconstruction system. Two new flooding models have been developed. The first one is flood spreading model which is useful for large scale flood simulation. It consists of flooding image spatial segmentation, a water level calculation process, a standard gradient descent method for energy minimization, a flood region search and a merge process. The finite volume hydrodynamic model is built from shallow water equations which is useful for urban area flood simulation. The proposed 3D urban environment reconstruction system was tested on our simulation platform. The experiment results indicate that this method is capable of dealing with complicated and high resolution region reconstruction which is useful for many applications. When testing the 3D flood simulation system, the simulation results are very close to the real flood situation, and this method has faster speed and greater accuracy of simulating the inundation area in comparison to the conventional flood simulation models
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Kühner, Tilman [Verfasser], and C. [Akademischer Betreuer] Stiller. "Large-Scale Textured 3D Scene Reconstruction / Tilman Kühner ; Betreuer: C. Stiller." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/1221186965/34.
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Selin, Magnus. "Efficient Autonomous Exploration Planning of Large-Scale 3D-Environments : A tool for autonomous 3D exploration indoor." Thesis, Linköpings universitet, Artificiell intelligens och integrerade datorsystem, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-163329.
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Exploration is of interest for autonomous mapping and rescue applications using unmanned vehicles. The objective is to, without any prior information, explore all initially unmapped space. We present a system that can perform fast and efficient exploration of large scale arbitrary 3D environments. We combine frontier exploration planning (FEP) as a global planning strategy, together with receding horizon planning (RH-NBVP) for local planning. This leads to plans that incorporate information gain along the way, but do not get stuck in already explored regions. Furthermore, we make the potential information gain estimation more efficient, through sparse ray-tracing, and caching of already estimated gains. The worked carried out in this thesis has been published as a paper in Robotand Automation letters and presented at the International Conference on Robotics and Automation in Montreal 2019.
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Yiakoumettis, Christos. "Semantic navigation of large scale geo-referenced 3D scenes and virtual worlds." Limoges, 2012. https://aurore.unilim.fr/theses/nxfile/default/389358e4-be58-45f6-8896-1e8dc57d1b24/blobholder:0/2012LIMO4049.pdf.
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The current technological evolutions introduce 3D geo-informatics to their digital age, enabling new potential applications in the field of virtual tourism, recreation, entertainment and cultural heritage. Virtual 3D worlds and geo-referenced scenes are used even more in simulations of physical disasters or in evacuating and military scenarios. It is argued that 3D information provides the natural way of navigation. However, personalization is a key aspect in a navigation system, since a route that incorporates user preferences is ultimately more suitable than a route which simply provides the shortest distance or travel time. An efficient personalized route planning architecture is based on geometrical criteria and on human factors regarding user's preferences in the 3D itinerary. In this work a multi-layer integrated framework is introduced for efficient, user-centric navigation of 3D worlds. Usually, user's preferences are expressed as a set of weights that regulate the degree of importance of the scene semantic metadata on the route selection process. These weights, however, are defined by the users, setting the complexity on the user's side, which makes personalization an arduous task. In this work, an alternative approach is proposed in which metadata weights are estimated implicitly and transparently to users, transferring the complexity to the system side. This is achieved by introducing a relevance feedback online learning strategy which automatically adjusts metadata weights by exploiting information fed back to the system about the relevance of user's preferences judgments given in a form of pairwise comparisons. Practically implementing a relevance feedback algorithm presents the limitation that several pairwise comparisons (samples) are required to converge to a set of reliable metadata weights. For this reason, in this work a weight rectification strategy is proposed which improves weight estimation by exploiting metadata interrelations defined through an ontology. In the sequel, a genetic optimization algorithm is incorporated to select the user's most preferred routes based on a multi-criteria optimization approach. To increase the degree of personalization in 3D navigation, an efficient algorithm is also introduced for estimating 3D trajectories around objects of interest by merging best selected 2D projected views that contain faces which are mostly preferred by users. Simulations and comparisons have been conducted with other approaches either in the field of online learning or route selection using objective metrics in terms of precision and recall valuesLes évolutions technologiques actuelles font entrer la géo-informatique 3D à son âge numérique, permettant de nouvelles applications potentielles dans le domaine du tourisme virtuel, du loisir, du divertissement et du patrimoine culturel. Des mondes virtuels 3D et des scènes géo-référencées sont utilisés encore plus dans les simulations de catastrophes physiques et de plan d'évacuation ou de scénarios militaires. Il est prouvé que les informations 3D offrent un moyen naturel de navigation. Cependant la personnalisation est un aspect essentiel dans un système de navigation. En dehors des optimisations de distance et du temps l'intégration des préférences des utilisateurs est finalement le point les important d'une navigation. Une architecture efficace de planification d'itinéraire personnalisée est basée tant sur des critères géométriques que sur les préférences de l'utilisateur. Dans ce travail, un cadre multi-couche intégrée est introduit, pour soutenir une navigation efficace centrée sur l'utilisateur, dans des mondes 3D. Habituellement, les préférences de l'utilisateur sont exprimées sous forme d‟un ensemble de poids qui représente le degré d'importance du contenu des métadonnées sémantiques de la scène sur le processus de sélection du tracé. Ces poids, cependant, sont définis par les utilisateurs, en mettant la complexité du côté de l'utilisateur, ce qui rend la personnalisation une tâche ardue. Dans ce travail, une approche alternative est proposée dans laquelle les poids du contenu des métadonnées sont estimés implicitement et de façon transparente pour les utilisateurs, en déplaçant la complexité du côté du système. Ce résultat est obtenu par l'introduction d'une stratégie d'apprentissage en ligne par retour d'expérience qui ajuste automatiquement les poids de variables des métadonnées par exploitation de l'information renvoyée vers le système sur la pertinence des jugements de préférences utilisateur présentés sous une forme de comparaisons par paires. Dans la pratique la mise en oeuvre d'un algorithme de retour d'expérience présente la limitation que plusieurs comparaisons par paires (échantillons) sont nécessaires pour converger vers un ensemble de poids de variables des métadonnées fiables. Pour cette raison, dans ce travail une stratégie de rectification de poids est proposée qui permet d'estimer le poids en exploitant les interrelations de variables de métadonnées définies par une ontologie. Dans la suite, un algorithme d'optimisation génétique est proposé pour sélectionner les itinéraires les plus préférés de l'utilisateur basé sur une approche d'optimisation multi-critères. Pour améliorer le degré de personnalisation en navigation 3D, un algorithme efficace est également mis en place pour estimer les trajectoires 3D autour des objets choisis par la fusion de meilleurs vues projetées en 2D qui contiennent des faces qui ont la plus grande préférence des utilisateurs. Des simulations et des comparaisons ont été effectuées avec d'autres approches, soit dans le domaine de l'apprentissage en ligne ou du choix du tracé en utilisant des mesures objectives en termes de précision et de rappel des valeurs
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Miksik, Ondrej. "Living in a dynamic world : semantic segmentation of large scale 3D environments." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:28050b9e-5e42-46b5-9a54-004450f812ec.
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As we navigate the world, for example when driving a car from our home to the work place, we continuously perceive the 3D structure of our surroundings and intuitively recognise the objects we see. Such capabilities help us in our everyday lives and enable free and accurate movement even in completely unfamiliar places. We largely take these abilities for granted, but for robots, the task of understanding large outdoor scenes remains extremely challenging. In this thesis, I develop novel algorithms for (near) real-time dense 3D reconstruction and semantic segmentation of large-scale outdoor scenes from passive cameras. Motivated by "smart glasses" for partially sighted users, I show how such modeling can be integrated into an interactive augmented reality system which puts the user in the loop and allows her to physically interact with the world to learn personalized semantically segmented dense 3D models. In the next part, I show how sparse but very accurate 3D measurements can be incorporated directly into the dense depth estimation process and propose a probabilistic model for incremental dense scene reconstruction. To relax the assumption of a stereo camera, I address dense 3D reconstruction in its monocular form and show how the local model can be improved by joint optimization over depth and pose. The world around us is not stationary. However, reconstructing dynamically moving and potentially non-rigidly deforming texture-less objects typically require "contour correspondences" for shape-from-silhouettes. Hence, I propose a video segmentation model which encodes a single object instance as a closed curve, maintains correspondences across time and provide very accurate segmentation close to object boundaries. Finally, instead of evaluating the performance in an isolated setup (IoU scores) which does not measure the impact on decision-making, I show how semantic 3D reconstruction can be incorporated into standard Deep Q-learning to improve decision-making of agents navigating complex 3D environments.
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Rudraraju, Anirudh V. "Digital data processing and computational design for large area maskless photopolymerization." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52930.
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Large Area Maskless Photopolymerization (LAMP) is a novel additive manufacturing technology currently being developed at Georgia Tech in collaboration with the University of Michigan at Ann Arbor and PCC Airfoils. It is intended for the fabrication of integrally cored ceramic molds for the investment casting of precision components such as high-pressure turbine blades. This dissertation addresses the digital data processing and computational design needs for this technology. Several data processing schemes like direct slicing, STL slicing, post-processing schemes like error checking, part placement and tiling etc. were developed in order to enable the basic functionality of the LAMP process. A detailed overview of these schemes and their implementation details are given in this dissertation. Several computational schemes to improve the quality and accuracy of parts produced through the LAMP process were also implemented. These include a novel volume deviation based adaptive slicing method to adaptively slice native CAD models, a gray scaling and dithering approach to reduce stair stepping effect on downward facing surfaces and a preliminary experimental study to characterize the side curing behavior of the LAMP photo-curable suspension for pre-build image compensation. The implementation details and a discussion of the results obtained using these schemes are given. A novel approach for addressing the “floating island” problem encountered in additive manufacturing was also developed. The need for supports specific to the kind of parts being built through LAMP is evaluated and a support generation strategy different from the previously reported approaches in the literature is presented. Finally, a few novel film cooling schemes that are extremely challenging to fabricate using existing manufacturing technologies but possible to fabricate using LAMP are chosen and analyzed for their cooling performance. It is shown that such novel schemes perform much better in cooling the blade surface than the conventionally implemented schemes and hence this final component of work gives a better appreciation of the impact LAMP technology has in disrupting the state of the art in turbine blade manufacturing and truly taking the blade designs to the next level.
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Teo, Nicholas J. "Nano, Micro and Macro Scale Control of Porous Aerogel Morphology." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron154989595598542.
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Simon, Loïc. "Procedural reconstruction of buildings : towards large scale automatic 3D modeling of urban environments." Phd thesis, Ecole Centrale Paris, 2011. http://tel.archives-ouvertes.fr/tel-00637638.
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This thesis is devoted to 2D and 3D modeling of urban environments using structured representations and grammars. Our approach introduces a semantic representation for buildings that encodes expected architectural constraints and is able to derive complex instances using fairly simple grammars. Furthermore, we propose two novel inference algorithms to parse images using such grammars. To this end, a steepest ascent hill climbing concept is considered to derive the grammar and the corresponding parameters from a single facade view. It combines the grammar constraints with the expected visual properties of the different architectural elements. Towards addressing more complex scenarios and incorporating 3D information, a second inference strategy based on evolutionary computational algorithms is adopted to optimize a two-component objective function introducing depth cues. The proposed framework was evaluated qualitatively and quantitatively on a benchmark of annotated facades, demonstrating robustness to challenging situations. Substantial improvement due to the strong grammatical context was shown in comparison to the performance of the same appearance models coupled with local priors. Therefore, our approach provides powerful techniques in response to increasing demand on large scale 3D modeling of real environments through compact, structured and semantic representations, while opening new perspectives for image understanding
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Parys, Roman [Verfasser], and Andreas [Akademischer Betreuer] Schilling. "Reconstruction of Large Scale 3D Models from Images / Roman Parys ; Betreuer: Andreas Schilling." Tübingen : Universitätsbibliothek Tübingen, 2014. http://d-nb.info/1162971363/34.
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Hittner, Brian Edward. "Rendering large-scale terrain models and positioning objects in relation to 3D terrain." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FHittner.pdf.
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Thesis (M.S. in Modeling, Virtual Environments and Simulation)--Naval Postgraduate School, December 2003.Thesis advisor(s): Don Brutzman, Curt Blais. Includes bibliographical references (p. 117-118). Also available online.
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Peterson, Dirk N. "Using large scale aerial images for 3D visualizations of Marion Sampson Park mountain bike trails." Diss., Maryville, Mo. : Northwest Missouri State University, 2008. http://www.nwmissouri.edu/library/theses/PetersonDirk/index.htm.
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Thesis (M.S.)--Northwest Missouri State University, 2008.The full text of the thesis is included in the pdf file. Title from title screen of full text.pdf file (viewed on December 17, 2008) Includes bibliographical references.
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Gattoni, Gaia. "Analysis of the infrastructures to build immersive visit at large scale." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022.
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This thesis aims to introduce some relevant notion to demonstrate how digital innovation may benefit all phases of the development of a construction project. It has proven possible, through the use of the BIM technique, to optimize the design, construction, and administration phases of structures. With the aid of virtual reality, it is feasible to reproduce a complete immersion experience of the structure during the design phase. The two scenarios illustrated in this thesis need to be considered as two different approaches to technological innovation. From LaVallée project, the first scenario, it can be stated that the BIM methodology applied in this context and then expanded to the concept of CIM is essential for the district's construction. The purpose is to predict and describe the quality of the environment and urban spaces in a project situation and to validate the results obtained. In order to do this, it is necessary to create an immersive visit with 3D modeling of the LaVallée area using BIM data, where these data are collected from different project partners in IFC format. With all of the information I gained from this study, I was able to employ the abilities to a different scenario: the Rimini port. The goal of this final part, is to reconstruct a three-dimensional visualization starting from a very basic level of information, which means looking for methods and tools that can easily represent a virtual visit through the use of 2D data.
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Cebecauer, Matej. "Short-Term Traffic Prediction in Large-Scale Urban Networks." Licentiate thesis, KTH, Transportplanering, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-250650.
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City-wide travel time prediction in real-time is an important enabler for efficient use of the road network. It can be used in traveler information to enable more efficient routing of individual vehicles as well as decision support for traffic management applications such as directed information campaigns or incident management. 3D speed maps have been shown to be a promising methodology for revealing day-to-day regularities of city-level travel times and possibly also for short-term prediction. In this paper, we aim to further evaluate and benchmark the use of 3D speed maps for short-term travel time prediction and to enable scenario-based evaluation of traffic management actions we also evaluate the framework for traffic flow prediction. The 3D speed map methodology is adapted to short-term prediction and benchmarked against historical mean as well as against Probabilistic Principal Component Analysis (PPCA). The benchmarking and analysis are made using one year of travel time and traffic flow data for the city of Stockholm, Sweden. The result of the case study shows very promising results of the 3D speed map methodology for short-term prediction of both travel times and traffic flows. The modified version of the 3D speed map prediction outperforms the historical mean prediction as well as the PPCA method. Further work includes an extended evaluation of the method for different conditions in terms of underlying sensor infrastructure, preprocessing and spatio-temporal aggregation as well as benchmarking against other prediction methods.QC 20190531
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Schott, Benjamin [Verfasser], and R. [Akademischer Betreuer] Mikut. "Interactive and Quantitative Knowledge-Discovery in Large-Scale 3D Tracking Data / Benjamin Schott ; Betreuer: R. Mikut." Karlsruhe : KIT-Bibliothek, 2018. http://d-nb.info/1174252219/34.
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Kim, Chul. "3D-SoftChip: A novel 3D vertically integrated adaptive computing system [thesis]." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2005. https://ro.ecu.edu.au/theses/656.
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At present, as we enter the nano and giga-scaled integrated-circuit era, there are many system design challenges which must be overcome to resolve problems in current systems. The incredibly increased nonrecurring engineering (NRE) cost, abruptly shortened Time-to- Market (ITA) period and ever widening design productive gaps are good examples illustrating the problems in current systems. To cope with these problems, the concept of an Adaptive Computing System is becoming a critical technology for next generation computing systems. The other big problem is an explosion in the interconnection wire requirements in standard planar technology resulting from the very high data-bandwidth requirements demanded for real-time communications and multimedia signal processing. The concept of 3D-vertical integration of 2D planar chips becomes an attractive solution to combat the ever increasing interconnect wire requirements. As a result, this research proposes the concept of a novel 3D integrated adaptive computing system, which we term 3D-ACSoC. The architecture and advanced system design methodology of the proposed 3D-SoftChip as a forthcoming giga-scaled integrated circuit computing system has been introduced, along with high-level system modeling and functional verification in the early design stage using SystemC.
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Abayowa, Bernard Olushola. "Automatic Registration of Optical Aerial Imagery to a LiDAR Point Cloud for Generation of Large Scale City Models." University of Dayton / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1372508452.
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Woods, Benjamin Samuel. "Enhancing the Capabilities of Large-Format Additive Manufacturing Through Robotic Deposition and Novel Processes." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/98843.
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The overall goal of this research work is to enhance the capabilities of large-format, polymer material extrusion, additive manufacturing (AM) systems. Specifically, the aims of this research are to (1) Construct, and develop a robust workflow for, a large-format, robotic, AM system; (2) Develop an algorithm for determining and relaying proper rotation commands for 5 degree of freedom (DoF) multi-axis deposition; and (3) Create a method for printing a removable support material in large-format AM. The development and systems-integration of a large-format, pellet-fed, polymer, material extrusion (ME), AM system that leverages an industrial robotic arm is presented. The robotic arm is used instead of the conventional gantry motion stage due to its multi-axis printing ability, ease of tool changes for multi-material deposition and/or subtraction, and relatively small machine footprint. A novel workflow is presented as a method to control the robotic arm for layer-wise fabrication of parts, and several machine modifications and workflow enhancements are presented to extend the multi-axis manufacturing capabilities of the robot. This workflow utilizes existing AM slicers to simplify the motion path planning for the robotic arm, as well as allowing the workflow to not be restricted to a single robotic deposition system.
To enable multi-axis deposition, a method for generating tool orientations and resulting deposition toolpaths from a geometry's STL file was developed for 5-DoF conformal printing and validated via simulation using several different multi-DOF robotic arm platforms. Furthermore, this research proposes a novel method of depositing a secondary sacrificial support material was created for large-format AM to enable the fabrication of complex geometries with overhanging features. This method employs a simple tool change to deposit a secondary, water-soluble polymer at the interfaces between the part and supporting structures. In addition, a means to separate support material into smaller sections to extend the range of geometries able to be manufactured via large-format AM is presented. The resultant method was used to manufacture a geometry that would traditionally be considered unprintable on conventional large-format AM systems.Master of Science
Additive manufacturing (AM), also known as 3D printing, is a method of manufacturing objects in a layer-by-layer technique. Large-format AM is typically defined as an AM system that can create an object larger than 1 m3. There are only a few manufacturers in the world of these systems, and all currently are built on gantry-based motion stages that only allow movement of the printer in three principal axes (X, Y, Z). The primary goal of this thesis is to construct a large-format AM system that uses a robotic arm to enable printing in any direction or orientation. The use of an industrial robotic arm enables printing in multiple planes, which can be used to print structures without support structures, print onto curved surfaces, and to purt with curved layers which produces a smoother external part surface. The design of the large-format AM system was validated through successful printing of objects as large as 1.0x0.5x1.2 m, simultaneous printing of a sacrificial support material to enable overhanging features, and through completing multi-axis printing. To enable multi-axis printing, an algorithm was developed to determine the proper toolpath location and relative orientation to the part surface. Using a part's STL file as input, the algorithm identifies the normal vector at each movement command, which is then used to calculate the required tool orientation. The tool orientations are then assembled with the movement commands to complete the multi-axis toolpath for the robot to perform. Finally, this research presents a method of using a second printing tool to deposit a secondary, water-soluble material to act as supporting structures for overhanging and bridging part features. While typical 3D printers can generally print sacrificial material for supporting overhangs, large-format printers produce layers up to 25 mm wide, rendering any support material impossible to remove without post-process machining. This limits the range of geometries able to be printed to just those with no steep overhangs, or those where the support material is easily reachable by a tool for removal. The solution presented in this work enables the large scale AM processes to create complex geometries.
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Liu, Jun. "A Combination method of Fingerprint Positioning and Propagation Model Based localization scheme in 3D Large-Scale Indoor Space." Thesis, Mittuniversitetet, Avdelningen för informationssystem och -teknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-34918.
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To achieve the concrete aim of improving the positioning accuracy for large-scale indoor space in this thesis, we propose a weighted Gaussian and Mean hybrid filter (G-M filter) to obtain the G-M mean of received signal strength indicator (RSSI) measurements, which is implemented by taking the practically experimental measurements of received signal strength indicator and analyzing the characteristics of received signal strength indicator. Meanwhile, various path loss models have been utilized to estimate the separation between the transmitting antenna and the receiver (T-R separation) by calculating the G-M mean of received signal strength indicator, therefore, a dynamic-parameter path loss model has been proposed which can be appropriate to enhance the accuracy of estimated T-R separation and accurately describe the indoor position. Moreover, an improved fingerprint positioning has been proposed as the basic method combined with our tetrahedral trilateration scheme to reduce the positioning error of a large-scale 3D indoor space which can achieve the average localization error of 1.5 meters.
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Graehling, Quinn R. "Feature Extraction Based Iterative Closest Point Registration for Large Scale Aerial LiDAR Point Clouds." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1607380713807017.
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Hassan, Raju Chandrashekara. "ANALYSIS OF VERY LARGE SCALE IMAGE DATA USING OUT-OF-CORE TECHNIQUE AND AUTOMATED 3D RECONSTRUCTION USING CALIBRATED IMAGES." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1189785164.
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Hayden, Shane Makana. "Introducing the VuePod: Development and Testing of a Low-Cost Large-Scale Stereoscopic Immersive System Using 3D LCD Televisions." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3823.
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3D immersive visualization systems, or CAVEs™, have found wide adoption for use in geosciences, planetary science, medical research, and computer science. However, much of the potential for such systems in practical civil and environmental engineering settings has been severely limited due to 1) extreme costs in both hardware and software; 2) immobility due to calibration and darkroom requirements; and 3) extensive and expensive manpower requirements for both operation and maintenance. This thesis presents the development and testing of a new mobile low-cost immersive stereo visualization system -- the "VuePod" -- that attempts to address these challenges through the use of commercial-off-the-shelf technologies, open source software, consumer grade passive 3-D television monitors, an active tracking system, and a modular construction approach. The VuePod capitalizes on recent functional advancements and cost decreases in both hardware and software and is demonstrated herein as a viable alternative to projector-based walk-in CAVEs and their limitations. Additionally, I have selected twelve representative 3D immersive systems and performed a side-by-side analysis of each in terms of cost, viewing capabilities, computing and user experience. The purpose of performing this analysis is to classify the variety of systems available and simplify the system procurement and configuration processes. The availability of this comparative system information should facilitate the increased utilization of immersive 3D interface technologies in science and engineering.
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Minz, Jacob Rajkumar. "Physical Design Automation for System-on-Packages and 3D-Integrated Circuits." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14012.
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The focus of this research was to develop interconnect-centric
physical design tools for 3D technologies.
A new routing model for the SOP structure was developed which
incorporated the 3D structure and formalized the resource structure
that facilitated the development of the global routing tool.
The challenge of this
work was to intelligently convert the 3D SOP routing problem into a set
of 2D problems which could be solved efficiently.
On the lines of MCM, the global routing problem
was divided into a number of phases namely, coarse pin distribution,
net distribution, detailed pin distribution, topology generation, layer
assignment, channel assignment and local routing. The novelty in this
paradigm is due to the feed-through vias needed by the nets which traverse
through multiple placement layers. To gain further improvements in
performance, optical
routing was proposed and a cost analysis study was done. The areas for
the placement of waveguides were efficiently determined, which reduced
delays and maximized utilization.
The global router developed was integrated into a simulated-annealing based
floorplanner to investigate trade-offs of various objectives. Since power-supply
noise suppression is of paramount importance in SOP, a model was developed
for the SOP power-supply network. Decap allocation, and
insertion were also integrated into the framework. The challenges
in this work were to integrate computationally intensive analysis tools with
a floorplanning that works to its best efficency provided the evaluation of
the cost functions are rapid. Trajectory-based approaches were used to sample
representative data points for congestion analysis and interpolate the
the congestion metric during the optimization schedule. Efficient
algorithms were also proposed for 3D clock routing, which acheived
equal skews under uniform and worst thermal profiles. Other
objectives such as wirelength, through-vias, and
power were also handled.
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Xinyu, Chang. "Neuron Segmentation and Inner Structure Analysis of 3D Electron Microscopy Data." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1369834525.
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Lundgren, Herman. "Participatory design of a 3D-printed furniture concept for learning spaces : A study of large-scale additive manufacturing opportunities and limitations." Thesis, Luleå tekniska universitet, Institutionen för ekonomi, teknik, konst och samhälle, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-86535.
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Today, learning spaces are stuck in the industrial age with rows of desks and chairs. Differentiated teaching and personalised learning are not effective in traditional learning spaces and should focus on creating future classrooms (Kariippanon, 2017). This thesis is covering how furnishing for learning environments can be improved and designed through a participatory design process with Katedralskolan in Växjö by using recycled materials and additive manufacturing technology. The thesis is also exploring the opportunities of involving stakeholders to create new learning through the additive manufacturing process in interior and furniture design. Together with Katedralskolan and Sculptur, this project is exploring a concept for schools to have integrated education in interior design through semiotics that will contribute to students’ learning and explore large-scale additive manufacturing. The objective is to design a collection of interior products that will inform and communicate at an educational level and how a circular manufacturing technique is possible through 3D-printing using communicating design and semiotics. The aim is also to understand Sculptur’s product development- and manufacturing process through large-scale 3D-printing. The mission statement whereas follows: Develop a furniture concept based on an understanding of the needs of, and participation with, the user group in a co-design process as a case to study the large-scale additive manufacturing techniques together with the given conditions provided by Sculptur. The thesis process has been following an iterative design process called the design thinking process (The Interaction Design Foundation, 2021) and a co-designing process (Sanders, 2018). The design thinking process is a design methodology that provides a solution-based approach to solving problems. The five stages of Design Thinking are as follows: Empathise, Define, Ideate, Prototype, Test. Through studies, surveys, and observations a list of stakeholder needs was created and was used when developing ideas through workshops, drawings, and prototyping. The ideas were then developed into concepts that were tested through both desktop 3D-printing and large-scale additive manufacturing. The concepts were also evaluated by stakeholders as well as through a concept evaluating matrix (Wikberg N., et.al., 2015). The result of this master thesis is the conclusion of the furniture concept as well as the study of large-scale additive manufacturing as an industrial designer. The furniture concept “Unfold lounge chair” is based on stakeholder needs and manufacturing restrictions. It is also an attempt to use theory to make the next generation of pedagogical furnishings using sustainable and circular manufacturing techniques. Through design thinking, the master thesis result was created with a human-centred approach to integrate the needs of people, the possibilities of technology and the requirements for business success (IDEO, n.d.).Idag sitter läromiljöer fast i den industriella epoken med rader av skrivbord och stolar. Differentierad undervisning och personlig inlärning är inte effektiv i traditionella läromiljöer och bör vara i fokus för att skapa framtidens klassrum (Kariippanon, 2017). Detta examensarbete tar upp hur inredning för inlärningsmiljöer kan förbättras och utformas genom en deltagande designprocess med Katedralskolan i Växjö med hjälp av återvunna material och additiv tillverkningsteknik. Arbetet har också undersökt möjligheterna att involvera intressenter för att skapa nytt lärande genom tillämpning av additiv tillverkning inom inredning och möbeldesign. Tillsammans med Katedralskolan och Sculptur har detta projekt undersökt ett koncept för skolor att ha integrerad utbildning i möbler genom semiotik och pedagogisk design som kommer att bidra till elevernas lärande samt utforska storskalig additiv tillverkning. Målet är att utforma en samling möbelkoncept som informerar och kommunicerar på utbildningsnivå och hur en cirkulär tillverkningsteknik är möjlig genom 3D-printnig med hjälp av kommuniationsdesign och semiotik. Målet är också att förstå Sculpturs produktutvecklings- och tillverkningsprocess genom storskalig additiv tillverkning. Projektets Mission statement var följande: Utveckla ett möbelkoncept baserat på en förståelse av behoven hos användargruppen i en samdesignprocess som ett fall för att studera storskalig additiv tillverkning tillsammans med de givna förutsättningarna från Sculptur. Examensarbetet har följt en iterativ designprocess som kallas design thinking process (The Interaction Design Foundation, 2021) tillsammans med en co-designprocess (Sanders, 2018). Design thinking är en designmetodik som ger en lösningsbaserad metod för att lösa problem. De fem faserna i design thinking är följande: Empathise, Define, Ideate, Prototype, Test. Genom studier, undersökningar och observationer skapades en lista över intressenters behov och användes när idéer utvecklades genom workshops, skisser och prototyper. Idéerna utvecklades sedan till koncept som sedan testades genom både mindre 3D-utskrift och storskalig additiv tillverkning. Koncepten utvärderades också av intressenter samt genom en konceptviktningsmatris (Wikberg N., et.al., 2015). Resultatet av detta examensarbete är sammanfattningen av möbelkonceptet samt studien av storskalig additiv tillverkning som industridesigner. Möbelkonceptet ”Unfold lounge chair” bygger på intressenternas behov samt tillverkningsrestriktioner. Det är också ett försök att använda teori för att skapa nästa generation av pedagogiska möbler med hållbara och cirkulära tillverkningstekniker. Genom design thinking skapades resultatet med ett mänskligt centrerat tillvägagångssätt för att integrera människors behov, teknikens möjligheter och kraven för produktens framgång (IDEO, n.d.).
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Engel, Jakob-Julian [Verfasser], Daniel [Akademischer Betreuer] Cremers, Daniel [Gutachter] Cremers, and Andrew [Gutachter] Davison. "Large-Scale Direct SLAM and 3D Reconstruction in Real-Time / Jakob-Julian Engel ; Gutachter: Daniel Cremers, Andrew Davison ; Betreuer: Daniel Cremers." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1149824174/34.
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Feuray, William. "Multiplexeurs Accordables pour Application Spatiale." Thesis, Limoges, 2017. http://www.theses.fr/2017LIMO0115/document.
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Cette thèse a pour but d’étudier le principe d’un multiplexeur de sortie accordable pour la charge utile d’un satellite de télécommunication. La première étape consiste à analyser les principales topologies de multiplexeur de sortie utilisables et les comparer pour en retirer le meilleur candidat pour cette application. Par la suite, diverses études ont été menées sur des composants passifs imprimés en 3D plastique et métallisés de diverses manières, en cherchant à comprendre comment améliorer au mieux les résultats de ces prototypes. La dernière partie de ce manuscrit détaille la conception d’un multiplexeur à deux canaux pouvant être utilisé sur trois états différents en large bande à 19 GHz. Ces états sont créés par des bandes passantes relatives variant de 1,6 à 4,8 % et une réalisation de deux maquettes sert de preuves de concept et de performance (une en plastique métallisé et la seconde en aluminium usiné)This thesis is about study of tunable output multiplexer principle for telecommunication satellite payload. The first step is analysis of the main topologies of output multiplexers and to compare them to conclude with the best candidate. Then, several studies were conducted on 3D plastic printed passive components with specific metallizations, searching how to improve results in term of losses and precision. Last part detailed two channels multiplexer design which can be used on three different states of relative bandwidth from 1.6 to 4.8 % at 19 GHz, and realization of two concept proof prototypes (one in metallized 3D printed plastic and another one in machined aluminum)
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Klimke, Jan [Verfasser], Jürgen [Akademischer Betreuer] Döllner, Robert [Akademischer Betreuer] Hirschfeld, Jürgen Gutachter] Döllner, Hartmut [Gutachter] [Asche, and Birgit [Gutachter] Kleinschmit. "Web-based provisioning and application of large-scale virtual 3D city models / Jan Klimke ; Gutachter: Jürgen Döllner, Hartmut Asche, Birgit Kleinschmit ; Jürgen Döllner, Robert Hirschfeld." Potsdam : Universität Potsdam, 2018. http://d-nb.info/1218169192/34.
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Klimke, Jan [Verfasser], Jürgen [Akademischer Betreuer] Döllner, Robert [Akademischer Betreuer] Hirschfeld, Jürgen [Gutachter] Döllner, Hartmut [Gutachter] Asche, and Birgit [Gutachter] Kleinschmit. "Web-based provisioning and application of large-scale virtual 3D city models / Jan Klimke ; Gutachter: Jürgen Döllner, Hartmut Asche, Birgit Kleinschmit ; Jürgen Döllner, Robert Hirschfeld." Potsdam : Universität Potsdam, 2018. http://d-nb.info/1218169192/34.
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Nachabe, Nour. "Évaluation des technologies d'impression 3D pour le développement d'antennes directives à large bande passante pour les liaisons backhaul en bandes millimétriques V et E." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4118/document.
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Face à la demande croissante de débits de données de plus en plus élevées, l’une des principales solutions proposées par la 5G est de densifier le réseau en y intégrant notamment de nouvelles « Small cells ». La réorganisation de l’architecture du réseau mobile pour s’adapter à l’intégration poussée de ces Small cells, fait naître la problématique de la connexion backhaul entre les stations de bases desservant les Small cells et le cœur de réseau. Ainsi, des liaisons backhaul de plusieurs Gb/s de données sont nécessaires pour pouvoir assurer un débit de données d’au moins 100Mb/s à l’utilisateur qui est l’un des objectifs fixés pour la 5G. Les solutions de connexion backhaul sans fils ont un avantage indiscutable face aux coûts de déploiements de fibres optiques qui sont très élevés. Pour augmenter la capacité spectrale des liaisons sans fils, l’utilisation des fréquences millimétriques au-delà de 6 GHz caractérisées par des larges bandes passantes sera prochainement discutée pour la 5G durant le World Radiocommunication Conference 2019. Parmi ces fréquences, les bandes V (57-66GHz) et E (71-76 GHz et 81-86 GHz) ont un intérêt indéniable grâce aux larges bandes passantes disponibles ainsi qu’aux conditions de licenciement peu exigeantes. Les travaux développés dans cette thèse consistent à concevoir des antennes directives à large bande passante permettant d’établir les liens backhaul point-à-point sans fils (LoS). En exploitant les technologies de fabrications à faibles coût telles que l’impression 3D et Printed Circuit Board (PCB) sur des substrats FR4, la conception de deux types d’antenne directives a été étudiée à savoir des antennes lentilles et des antennes réseauxIn order to address the ever-increasing demand of higher data rates, adding small cells to the existing macrocells infrastructure is one of the most important milestones of the 5G roadmap. With the integration of small cells and the re-organization of the network topology, backhaul bottleneck is the main challenge to address in the near future. Facing the costs of deployments of fiber optic connections, point-to-point wireless backhaul links using millimeter wave (mmW) frequencies are gaining prominence. 5G future frequencies, to be discussed under the World Radiocommunication Conference 2019 (WRC-19) open-up the way towards mmW frequency band where large bandwidths are naturally available. The high bandwidths available at these frequencies enable several Gbps data rate backhaul links, which is un utmost necessity to respect the 100 Mbps user-experienced data rate promised by the 5G standard. Millimeter-wave frequencies in V and E-bands unlicensed/light licensed spectrum are considered as primary candidates for backhaul links. In addition to the light license regime, the high free space path loss experienced at these frequencies is rather beneficial to limit the interference between small cells links. Moreover, the high available bandwidths at V and E-bands enable to achieve multi Gb/s links without using complex modulation schemes. In this thesis, we focused our research study on developing high gain wide-band antennas usable in point-to-point backhaul links in a Line of Sight (LoS) context. Leveraging cost-efficient technologies like 3D printing and Printed Circuit Board (PCB) on FR4 substrates, we studied two high-gain antenna types: lens antennas and flat array antennas
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Su, Po-Chang. "A ROBUST RGB-D SLAM SYSTEM FOR 3D ENVIRONMENT WITH PLANAR SURFACES." UKnowledge, 2013. http://uknowledge.uky.edu/ece_etds/17.
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Simultaneous localization and mapping is the technique to construct a 3D map of unknown environment. With the increasing popularity of RGB-depth (RGB-D) sensors such as the Microsoft Kinect, there have been much research on capturing and reconstructing 3D environments using a movable RGB-D sensor. The key process behind these kinds of simultaneous location and mapping (SLAM) systems is the iterative closest point or ICP algorithm, which is an iterative algorithm that can estimate the rigid movement of the camera based on the captured 3D point clouds. While ICP is a well-studied algorithm, it is problematic when it is used in scanning large planar regions such as wall surfaces in a room. The lack of depth variations on planar surfaces makes the global alignment an ill-conditioned problem. In this thesis, we present a novel approach for registering 3D point clouds by combining both color and depth information. Instead of directly searching for point correspondences among 3D data, the proposed method first extracts features from the RGB images, and then back-projects the features to the 3D space to identify more reliable correspondences. These color correspondences form the initial input to the ICP procedure which then proceeds to refine the alignment. Experimental results show that our proposed approach can achieve better accuracy than existing SLAMs in reconstructing indoor environments with large planar surfaces.
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Puttaswamy, Kiran. "Designing high-performance microprocessors in 3-dimensional integration technology." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19759.
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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.Committee Chair: Loh, Gabriel H.; Committee Co-Chair: Lee, Hsien-Hsin S.; Committee Member: Lim, Sung Kyu; Committee Member: Prvulovic, Milos; Committee Member: Yalamanchili, Sudhakar; Committee Member: Yoder, Douglas.
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Kleinfehn, Alex Patrick. "Scale-Up of Modifiable Poly(propylene fumarate) and Surface Functionalization of Additive Manufactured Scaffolds for Bone Tissue Regeneration." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1562679460809562.
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Leksell, Torbjörn. "Can market specialization reduce the entry cost of automated largescale 3D-scanning of movable artifacts for culture and heritage preservation?" Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234308.
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Automated, large-scale 3D-scanning systems are important tools in culture and heritage preservation that allows museums and art institutes to digitize their collections of movable artifacts for the purpose of preservation, research, and exhibition. Unfortunately, the cost of these systems limits their usage to a handful of wealthy museums and art institutes. This thesis explores if it possible to significantly reduce the cost of such a system by presenting a viable automated, large-scale, 3D-scanning system for movable artifacts tailored to the needs of museums and art institutes. To achieve the thesis goal a market analysis was conducted to identify the need and requirements museums and art institutes have for these kinds of systems. The market analysis also explored available systems on the market and how museums and art institutes use them. The result of the market analysis identified a specific type of automated, large-scale, 3D-scanning system design suitable for market specialization. Based on the market analysis requirements for such a system design were specified and developed into a mechanical design and hardware architecture. These were then used to construct and evaluate a limited prototype as a way of validating the mechanical design and hardware architecture. The remainder of the work consisted of a cost analysis which used the hardware architecture and mechanical designs to estimate the material and component cost to produce a single unit of the developed system. The results of this thesis show that it is probable that market specialization significantly reduces the cost for museums and art institutes to purchase an automated, large-scale, 3D-scanning system compared with available market alternatives.Automatiserade 3D-scanners som kan 3D-scanna stora volymer av konstprodukter är viktiga verktyg inom kulturhistorisk bevaring då det tillåter museum att digitalisera samlingar i syfte att bevara, forska och ställa ut. Tyvärr så är dessa system dyra och bara ett fåtal museer har resurser nog för att köpa in dem. Denna uppsats utforskar ifall det är möjligt att betydligt reducera kostnaden av ett sådant system genom att presentera en fungerande automatiserad 3D-scanner som är specifikt anpassad för museum. Arbetet började med en marknadsanalys som identifierade kraven som museum ställer på denna typ av system samt en analys av tillgängliga system på marknaden och hur museum använder dessa. Resultatet av detta arbete var att en specifik typ av automatiserad 3D-scannar lämplig för anpassning identifierades. Utifrån kraven som identifierades genom marknadsanalysen så utvecklades sedan en mekanisk och elektrisk design för systemet. Dessa användes sedan för att bygga och utvärdera en begränsad prototyp i syfte att validera den mekaniska och elektriska designen. Resterande arbete bestod av en kostnadsanalys som använde den mekaniska och elektriska designen för att utvärdera material och komponentkostnaden för att bygga en enhet av det utvecklade systemet. Slutsatsen av arbetet i denna uppsats är att det är troligt att det blir billigare för museum att köpa denna typ av system ifall de utvecklas utifrån deras specifika behov jämfört med tillgängliga system på marknaden.
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Llau, Antoine. "Méthodes de simulation du comportement mécanique non linéaire des grandes structures en béton armé et précontraint : condensation adaptative en contexte aléatoire et représentation des hétérogénéités." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAI029/document.
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Les structures en béton et béton armé de grandes dimensions, en particulier les enceintes de confinement, peuvent être sujettes à de la fissuration localisée suite à leur vieillissement ou dans le cas d’une forte sollicitation (APRP, par exemple). Afin d’optimiser les actions de maintenance, il est nécessaire de disposer d’un modèle prédictif de l’endommagement du béton. Ce phénomène se produit à une échelle matériau relativement petite et un modèle prédictif nécessite un maillage fin et une loi de comportement non linéaire. Hors ce type de modélisation ne peut être directement appliquée sur une structure de génie civil de grande échelle, le calcul étant trop lourd pour les machines actuelles.Une méthode de calcul est proposée, qui concentre l’effort de calcul sur les zones d’intérêt (parties endommagées) de la structure en éliminant les zones non endommagées. L’objectif est ainsi d’utiliser la puissance de calcul disponible pour la caractérisation des propriétés des fissures notamment. Cette approche utilise la méthode de condensation statique de Guyan pour ramener les zones élastiques à un ensemble de conditions aux limites appliquées aux bornes des zones d’intérêt. Lorsque le système évolue, un système de critères permet de promouvoir à la volée des zones élastiques en zones d’intérêt si de l’endommagement y apparaît. Cette méthode de condensation adaptative permet de réduire la dimension du problème non linéaire sans altérer la qualité des résultats par rapport à un calcul complet de référence. Cependant, une modélisation classique ne permet pas de prendre en compte les divers aléas impactant le comportement de la structure : propriétés mécaniques, géométrie, chargement… Afin de mieux caractériser ce comportement en tenant compte des incertitudes, la méthode de condensation adaptative proposée est couplée avec une approche de collocation stochastique. Chaque calcul déterministe nécessaire pour caractériser les incertitudes sur les grandeurs d’intérêt de la structure est ainsi réduit et les étapes de prétraitement nécessaires à la condensation sont elles-mêmes mutualisées via une deuxième collocation. L’approche proposée permet ainsi de produire pour un coût de calcul limité des densités de probabilités des grandeurs d’intérêt d’une grande structure. Les stratégies de résolution proposées rendent accessibles à l’échelle locale une modélisation plus fine que celle qui pourrait s’appliquer sur l’ensemble de la structure. Afin de bénéficier d’une meilleure représentativité à cette échelle, il est nécessaire de représenter les effets tridimensionnels des hétérogénéités. Dans le domaine du génie civil et nucléaire, cela concerne au premier chef les câbles de précontrainte, traditionnellement représentés en unidimensionnel. Une approche est donc proposée, qui s’appuie sur un maillage et une modélisation 1D pour reconstruire un volume équivalent au câble et retransmettre les efforts et rigidités dans le volume de béton. Elle combine la représentativité d’un modèle 3D complet et conforme des câbles lorsque le maillage s’affine et la facilité d’utilisation et paramétrage d’un modèle 1D. L’applicabilité des méthodes proposées à une structure de génie civil de grande échelle est évaluée sur un modèle numérique d’une maquette à l’échelle 1/3 de l’enceinte de confinement interne d’un réacteur de type REP 1300 MWe à double paroiLarge-scale concrete and reinforced concrete structures, and in particular containment buildings, may undergo localized cracking when they age or endure strong loadings (LOCA for instance). In order to optimize the maintenance actions, a predictive model of concrete damage is required. This phenomenon takes place at a rather small material scale and a predictive model requires a refined mesh and a nonlinear constitutive law. This type of modelling cannot be applied directly on a large-scale civil engineering structure, as the computational load would be too heavy for the existing machines.A simulation method is proposed to focus the computational effort on the areas of interest (damaged parts) of the structure while eliminating the undamaged areas. It aims at using the available computing power for the characterization of crack properties in particular. This approach uses Guyan’s static condensation technique to reduce the elastic areas to a set of boundary conditions applied to the areas of interest. When the system evolves, a set of criteria allows to promote on the fly the elastic areas to areas of interest if damage appears. This adaptive condensation technique allows to reduce the dimension of a nonlinear problem without degrading the quality of the results when compared to a full reference simulation.However, a classical modelling does not allow to take into account the various unknowns which will impact the structural behaviour: mechanical properties, geometry, loading… In order to better characterize this behaviour while taking into account the various uncertainties, the proposed adaptive condensation method is coupled with a stochastic collocation approach. Each deterministic simulation required for the characterization of the uncertainties on the structural quantities of interest is therefore reduced and the pre-processing steps necessary to the condensation technique are also reduced using a second collocation. The proposed approach allows to produce for a reduced computational cost the probability density functions of the quantities of interest of a large structure.The proposed calculation strategies give access at the local scale to a modelling finer than what would be applicable to the full structure. In order to improve the representativeness at this scale, the tridimensional effects of the heterogeneities must be taken into account. In the civil and nuclear engineering field, one of the main issues is the modelling of prestressing tendons, usually modelled in one dimension. A new approach is proposed, which uses a 1D mesh and model to build a volume equivalent to the tendon and redistribute the forces and stiffnesses in the concrete. It combines the representativeness of a full conform 3D modelling of the tendon when the mesh is refined and the ease of use of the 1D approaches.The applicability of the proposed methodologies to a large-scale civil engineering structure is evaluated using a numerical model of a 1/3 mock-up of a double-wall containment building of a PWR 1300 MWe nuclear reactor
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Liu, Chao Yuan. "Analyse quantitative des propriétés mécaniques de fraises dentaires rotatives en NiTi et étude de la fabrication de larges microstructures par polymérisation induite à deux photons." Phd thesis, Université de Grenoble, 2014. http://tel.archives-ouvertes.fr/tel-01071805.
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Un tiers des urgences dentaires et un pourcentage élevé de maux de dents sont endodontie liés. Instruments rotatifs utilisés dans le traitement endodontique peuvent se briser à l'intérieur du canal radiculaire en raison de la fatigue des matériaux. Une fois cassé, l'extraction de la partie fracturée du canal est un travail difficile et ennuyeux de le patient et le dentiste. Par conséquent, l'alerte d'une fracture imminente lors de l'utilisation clinique ou développer de bonnes stratégies pour augmenter ses propriétés mécaniques sera d'une grande aide pour éviter les complications médicales / juridique. La recherche est étudié à partir de deux parties. La première partie a établi une plate-forme de test standard, simulant plusieurs paramètres de canal, propose une série de stratégies visant à améliorer la vie de la fatigue et des propriétés mécaniques de matériaux. Aussi, un système de surveillance utilisant de réseaux de Bragg (FBG) capteurs a été tentée. la raison de l'utilisation de la glycémie à jeun est sa petite taille qui est très prometteur dans l'intégration avec la pièce à main de l'équipement endodontique. dans le travail actuel, en ramassant et en analysant l'onde de contrainte par transformée de Fourier rapide (FFT), nous peut révéler la variation d'énergie et la fréquence phénomène déplaçant dans certaines fréquences caractéristiques. on espère que, avec ces informations, nous pouvons éviter / atténuer la survenue de fracture inattendue. Comme pour l'essai de fatigue, les données ont montré que la résistance à la fatigue peut être améliorée certain traitement thermique ou à mouvement alternatif méthode de rotation appliqué. tel phénomène peut être étroitement liée à la composition de la phase en ni-Ti en alliage et la contrainte de traction maximale est réduite lorsque le mouvement alternatif appliqué. études ont montré que plus la teneur de la phase martensite dans l'aiguille, l'plus de vie à la fatigue peut être atteint. Cependant, il peut être nécessaire de prendre des compromis avec l'efficacité de coupe de l'aiguille. pour cette question, nous pouvons combiner le traitement cryogénique et traitement thermique pour obtenir une meilleure résistance à la fatigue sans compromettre son efficacité de coupe. La deuxième partie est de fabriquer haute résolution, grande taille de la nouvelle Type aiguilles d'endodontie en utilisant la polymérisation à deux photons (TTP) technique. Le travail se fait à l'université de Joseph-Fourier LiPhy laboratoire, France. Contrairement à la fabrication traditionnelle du PPT, qui avait une limitation de sa taille de produits en raison du faible pouvoir lase, taux de redoublement et piézo entraîné stade, nous utilisons résine Ormocer, 130 kHz, 1W puissant laser de 532 nm à l'étape motorisé étage XY pour fabriquer une grande 800 échafaud um cellulaire bio-compatible et 1.2 cm aiguille de hauteur. aussi, pour améliorer la qualité du produit de TPP, l'approche de correction de la puissance du laser avait été tentée. Pendant TPP fabrication, la forme de focalisation laser changé lorsque la surface de la fabrication a été déplacé dans la direction z. Cela se traduit par le fait que nous avons besoin de plus afin d'assurer la taille de voxel est identique à z différent. pour corriger ce défaut, un procédé pour la correction de la puissance du laser et de la formule pour la puissance de correction sont proposées. la formule est dérivé du concept de maintien de conditions d'exposition identiques.
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Jaber, Jana. "Application de la fabrication additive à la modélisation physique des joints et des massifs rocheux, par approches expérimentales et numériques." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0071.
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Cette thèse présente une étude de l’application de la fabrication additive (connue sous le nom d’impression 3D) à la mécanique des roches. Elle s’inscrit dans le cadre d’un projet plus large visant à construire un modèle physique de 2m3 d’un massif rocheux explicitement discontinu, dont le comportement est contrôlé principalement par les discontinuités. La technique de fabrication additive adoptée est le frittage laser (SLS), le matériau utilisé est un polymère : le polyamide 12 (PA12). Dans un premier temps des joints artificiels construits par SLS sont testés sous essais de cisaillement à contrainte normale constante. Deux familles de discontinuités sont étudiées. La première est formée par des joints à géométrie simplifiée (joints planaires ou en dents de scies) ayant une ouverture de 0,4mm et contenant des ponts rocheux. Les résultats montrent que cette technique de fabrication des joints en PA12 permet d’obtenir un comportement global similaire à celui des joints rocheux naturels, avec une cohésion pilotée par les ponts rocheux, et un angle de frottement dépendant de l’angle des aspérités. La deuxième famille est constituée de joints ayant des rugosités plus réalistes, auxquelles on peut attribuer une valeur de JRC, communément utilisée pour décrire les joints naturels. Cette configuration permet elle aussi de reproduire un comportement global équivalent à celui des joints naturels, avec une mobilisation des aspérités primaires et secondaires des surfaces. Les résultats obtenus sont comparés au critère de rupture de Barton-Bandis. Cette étude expérimentale est complétée par une modélisation numérique sous le logiciel UDEC, dans le but d’étudier la capacité des modèles existants à reproduire le comportement des joints artificiels obtenu expérimentalement, et de calibrer numériquement les paramètres mécaniques utilisés dans la modélisation pour représenter les essais expérimentaux. Dans un second temps, des éprouvettes cylindriques (16 x 32 cm) contenant deux ou huit discontinuités à géométrie simplifiée (planaire + ponts rocheux) sont fabriquées et testées sous compression uni-axiale. Il s’agit d’une première tentative d’un modèle réduit explicitement discontinu et contenant des joints ayant un comportement mécanique contrôlé. Les résultats permettent de mettre l’accent sur l’influence des discontinuités sur le comportement global d’un massif rocheux. Ces essais sont comparés à une modélisation numérique sous 3EDC. Finalement, et afin d’étudier l’applicabilité de cette technique à la modélisation physique, les lois de similitudes sont appliquées aux résultats obtenus dans les parties précédentes. Il en ressort qu’il est possible d’utiliser la SLS et le PA12 en modélisation physique des massifs rocheux, jusqu’un facteur d’échelle sur les dimensions métriques de 1/25This thesis presents a study of the application of additive manufacturing (known as 3D printing) to rock mechanics. It is part of a larger project aimed at building a 2m3 physical model of an explicit discontinuous rock mass, whose behaviour is mainly controlled by discontinuities. The 3DP technology adopted in this work is selective laser sintering, and the material is Polyamide 12. First, we present the experimental results of the mechanical characterization of artificial rock joints constructed by 3DP. Two joint families are tested. The first is characterized by a fixed aperture (0,4mm), a simplified geometry (planar or sawtooth), and containing rock bridges. The mechanical characterization shows that these joints exhibit a mechanical behavior similar to that of natural rock joints under shear tests, with a cohesion driven by the rock bridges, and a friction angle which depends on the angle of the asperities. The second family consists of joints with more realistic roughnesses, to which a JRC value, commonly used to describe natural joints, can be assigned. Again, experimental results show the potential of artificial joints to reproduce the mechanical behavior of natural joints, and to respect the Barton-Bandis criterion. Experimental studies are coupled with numerical modeling, using the UDEC software, to define the appropriate model that reproduces the experimental results, and to calibrate the mechanical parameters of both joints type. After defining different artificial joints with controlled parameters, cylindrical samples (16 x 32 cm) containing two and eight planar discontinuities with rock bridges are printed and tested under uni-axial compression. This is a first attempt at an explicitly discontinuous physical model containing joints with controlled mechanical behaviour. The mechanical behavior of these samples highlights the influence of discontinuities in controlling the global behavior and resistance of rock masses. The results are then compared to a numerical modeling under 3EDC. Finally, scaling laws are applied to the previous results. The application of scale factors to the experimental results shows the possibility of representing natural rock mass and rock joints with artificial 3DP joints (SLS technique) up to a scale factor on metric dimensions of 1/25
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Page, Marine. "Création d'objets mats : optimisation d’un procédé d’impression en relief en termes d’apparence." Thesis, Paris, CNAM, 2018. http://www.theses.fr/2018CNAM1204/document.
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L’impression 2.5D est une technologie à mi-chemin entre l’impression couleur traditionnelle, à laquelle elle emprunte son procédé et la qualité de reproduction des couleurs, et l’impression 3D qui crée des reliefs et des formes. Par ses qualités visuelles, elle pourrait permettre la reproduction réaliste de multiples surfaces, mais un frein s’oppose à cette perspective : les encres brillent. En modulant la rugosité des surfaces imprimées à l'échelle du micromètre, en fréquence et en amplitude, nous avons réussi à réduire et contrôler le brillant des encres. Des stratégies d'impression différentes ont été proposées et étudiées pour diminuer l’effet scintillant et permettre l’impression d’une couche couleur mate : la création d'un espace à cinq dimensions dans lequel le brillant et la couleur sont modélisés aboutit à l'uniformisation des niveaux de brillant colorés. Les protocoles d'impression développés ont ensuite été appliqués à des cas concrets issus de la conservation – restauration du patrimoine. Plusieurs exemples distincts sont présentés, qui abordent un point particulier sur lequel l’impression 2.5D est pertinente: comblement de lacune, création de répliques réalistes, intérêt de l'aspect visuel mat pour la lisibilité des œuvres2.5D printing is between traditional color printing, for the process and its visual quality, and 3D printing, which makes forms and reliefs by ink superposition. Because of its properties, 2.5D printing could allow the realistic reproduction of objects and surfaces, but inks are too glossy. To reduce and control this glossy aspect of inks, we modulate the roughness of the printed layers, at the micro-scale, both in frequency and amplitude. Influence of parameters was measured, and different strategies were suggested to reduce sparkle and to allow the creation of matte colored layers: by constituting a 5D space where gloss and color are modeled, we can make gloss level of colored surfaces uniform.Several case studies form the Conservation of Cultural Heritage were considered, where 2.5D printing could help the curator, the conservator or the archivist. We studied in particular the issues of the the gap filling on an archaeological object, the realistic reproduction of surfaces, and the creation of matte objects for readability
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Lodato, Guido. "Conditions aux limites tridimensionnelles pour la simulation directe et aux grandes échelles des écoulements turbulents : modélisation de sous-maille pour la turbulence en région de proche paroi." Phd thesis, INSA de Rouen, 2008. http://tel.archives-ouvertes.fr/tel-00585227.
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Le traitement des conditions aux limites et la modélisation fine des interactions de sous-maille ont été abordés dans cette thèse. La formulation caractéristique des conditions aux limites a été analysée et une nouvelle procédure 3D-NSCBC est proposée qui autorise la prise en compte de l'évolution de la vitesse et de la pression dans le plan des frontières, afin d'introduire le caractère tridimensionnel de l'écoulement dans les conditions limites. Des nouvelles formulations pour resoudre le couplage des ondes caractéristiques au niveau des arêtes et des coins ont été développées. Dans le cadre de la Simulation des Grandes Échelles, pour reproduire correctement la dynamique de la turbulence à la paroi et pour mieux prendre en compte l'anisotropie du tenseur des contraintes de sous-maille, un modèle structural fondé sur l'hypothèse de similarité est développé pour des écoulements modérément compressibles et validé sur la simulation d'un jet rond en impaction sur une paroi plane.
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Knychala, Tucci Thadeu. "Distributed algorithms for programmable matter : target shape description and self-assembly planning." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCD028.
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La matière programmable peut être vue comme un énorme robot modulaire dans lequel chaque module peut communiquer avec ses voisins connectés et travailler tous ensemble pour atteindre un objectif commun, modifiant la forme du robot et l'adaptant à nouvelles fonctionnalités.Afin de parvenir à une coordination entre un groupe de plusieurs milliers de robots, des règles locales et des algorithmes distribués profiteraient à ce type d'environnement. De la même manière, utiliser de petits modules signifient qu'il existe également des ressources restreintes et que les algorithmes doivent être conçus pour intégrer ces contraintes.Cette thèse fournit des algorithmes et des solutions pour résoudre certaines parties du problème d'auto-reconfiguration, chaque module intégrant le même algorithme et se coordonnant avec les autres au moyen d'une communication de voisin à voisin. L'une d'entre elles propose une représentation de la structure cible qui réduit la mémoire utilisée. De plus, l'auto-assemblage comme l'auto-reconfiguration se compose de deux étapes:(1) identifier les positions libres disponibles pour l'installation des modules et (2) déplacer et connecter les modules à ces positions. Dans cette thèse sont présentées des solutions distribuées pour la première étape qui peuvent décider des positions pouvant être remplies et peuvent créer n'importe quelle forme 3D, y compris des formes avec des trous internes et des concavitésProgrammable matter can be seen as a huge modular robot in which each module can communicate to its connected neighbors and work all together to achieve a common goal, more likely changing the shape of the whole robot and adapting it with new functionalities.In order to achieve coordination between a group with many thousand robots, local rules and distributed algorithms would take advantage in this environment. In the same way, small modules means there is also small resources and algorithms should be designed to reflect these needs.This thesis provide algorithms and solutions to solve some parts of the self-reconfiguration problem with each module embedding the same algorithm and coordinating with the others by means of neighbor-to-neighbor communication. One of them is a study and proposal of a representation for the goal structure that reduces the footprint memory. Also, the self-assembly like self-reconfiguration is composed of two steps:(1) identifying the free positions that are available for docking and (2) moving and docking modules to these positions. In this thesis, distributed solutions for the first step are presented which can decide positions that can be filled and can create any 3D shape, including shapes with internal holes and concavities
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Sahare, Swapnil Ashok. "Enhancing the Photovoltaic Efficiency of a Bulk Heterojunction Organic Solar Cell." TopSCHOLAR®, 2016. http://digitalcommons.wku.edu/theses/1609.
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Active layer morphology of polymer-based solar cells plays an important role in improving power conversion efficiency (PCE). In this thesis, the focus is to improve the device efficiency of polymer-based solar cells. In the first objective, active layer morphology of polymer-solar cells was optimized though a novel solvent annealing technique. The second objective was to explore the possibility of replacing the highly sensitive aluminum cathode layer with a low-cost and stable alternative, copper metal. Large scale manufacturing of these solar cells is also explored using roll-to-roll printing techniques.
Poly (3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl (PCBM) were used as the active layer blend for fabricating the solar cell devices using bulk heterojunction (BHJ), which is a blend of a donor polymer and an acceptor material. Blends of the donor polymer, P3HT and acceptor, PCBM were cast using spin coating and the resulting active layers were solvent annealed with dichlorobenzene in an inert atmosphere. Solvent annealed devices showed improved morphology with nano-phase segregation revealed by atomic force microscopy (AFM) analysis. The roughness of the active layer was found to be 6.5 nm. The nano-phase segregation was attributed to PCBM clusters and P3HT domains being arranged under the solvent annealing conditions. These test devices showed PCE up to 9.2 % with current density of 32.32 mA/cm2, which is the highest PCE reported to date for a P3HT-PCBM based system.
Copper was deposited instead of the traditional aluminum for device fabrication. We were able to achieve similar PCEs with copper-based devices. Conductivity measurements were done on thermally deposited copper films using the two-probe method. Further, for these two configurations, PCE and other photovoltaic parameters were compared.
Finally, we studied new techniques of large scale fabrication such as ultrasonic spray coating, screen-printing, and intense pulse light sintering, using the facilities at the Conn Center for Renewable Energy Research at the University of Louisville. In this study, prototype devices were fabricated on flexible ITO coated plastics. Sintering greatly improved the conductivity of the copper nano-ink cathode layer. We will explore this technique’s application to large-scale fabrication of solar cell devices in the future work.
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Mårtensson, Oskar. "LHCb Upstream Tracker box : Thermal studies and conceptual design." Thesis, Umeå universitet, Institutionen för fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-116163.
Full textAbstract:
The LHC (Large Hadron Collider) will have a long shut down in the years of 2019 and 2020, referred to as LS2. During this stop the LHC injector complex will be upgraded to increase the luminosities, which will be the first step of the high luminosity LHC program (which will be realized during LS3 that takes place in 2024-2026). The LHCb experiment, whose main purpose is to study the CP-violation, will during this long stop be upgraded in order to withstand a higher radiation dose, and to be able to read out the detector at a rate of 40MHz,compared to 1MHz at present. This change will improve the trigger efficiency significantly. One of the LHCb sub-detectors the Trigger Tracker (TT), will be replaced by a new sub-detector called UT. This report presents the early stage design (preparation for mock-up building) of the box that will be isolating the new UT detector from the surroundings and to ensure optimal detector operation. Methods to fulfill requirements such as light and gas tightness, Faraday-cage behavior and condensation free temperatures, without breaking the fragile beryllium beam pipe, are established.LHC (Large Hadron Collider) kommer under åren 2019-2020 att ha ett längre driftstopp. Under detta driftstopp så kommer LHC's injektionsanordningar att uppgraderas för att kunna sätta fler protoner i circulation i LHC, och därmed öka antalet partikelkollisioner per tidsenhet. Denna uppgradering kommer att vara första steget i "High Luminocity LHC"-programmet som kommer att realiseras år 2024-2026. LHCb-experimentet, vars främsta syfte är att studera CP-brott, kommer också att uppgraderas under stoppet 2019-2020. Framför allt så ska avläsningsfrekvensen ökas från dagens 1MHz till 40MHz, och experimentet ska förberedas för de högre strålningsdoser som kommer att bli aktuella efter stoppet 2024-2026. En av LHCb's deldetektorer, TT detektorn, kommer att bytas ut mot en ny deldetektor som kallas UT. Den här rapporten presenterar den förberedande designen av den låda som ska isolera UT från dess omgivning och försäkra optimala förhållanden för detektorn. Kraven på den isolerande lådan och tillvägagångssätt för att uppfylla dessa krav presenteras.
LHCb, LS2 and LS3 Upgrade