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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Výroba částí prototypových forem s využitím metod rapid prototyping / Production of prototype mold parts using rapid prototyping methods

Kaloda, Vít January 2020 (has links)
The diploma thesis pointed out the possibility of using rapid prototyping methods in the field of plastic injection, specifically to make shaped inserts into the injection mold. The universal frame of the injection mold was used and only the shaped inserts were changed. The main part of the work was the construction of an injection mold with the subsequent practical production of shaped inserts for a specified part. In the introductory part, a theoretical search was performed, about which production methods in combination with suitable materials could be theoretically used. Furthermore, the polyjet and DLP methods were chosen, which were used to produce components (core and cavity). The result of the diploma thesis was a summary of all parameters, comparison of materials and production methods. Polypropylene and polyamide 6 materials were injected into the injection mold, from which the first prototype products were made. Instructions for the production of shaped inserts with the recommended technology and material were created for the selected type, which could be used in practice.
322

Nové směry v konstrukci a výrobě forem pro voskové odlitky / New ways in manufacturing and construction of mould for wax casting

Dostál, Pavel January 2008 (has links)
The aim of this work is to compare technology of silicon and aluminium moulds used to make castings using technology of cire perdue with single – piece work. The work itself deals with physical production of silicon mould in vacuum casting system, shaping aluminium mould using CNC machine and subsequent casting of wax models into these moulds. It also handles with physical production of one piece by shaping. It contains background research of the method lost wax casting manufacturing aluminium and silicon moulds and last but not least of Rapid Prototyping technology for producing master model.
323

Sestavení a ověření funkčnosti domácí 3D tiskárny / Assembling and Functional Verification of a Home 3D Printer

Tesař, Jaroslav January 2014 (has links)
This thesis was created as a bachelor project in the Faculty of Mechanical Engineering at VUT in Brno. In the theoretical part, the additive technology Rapid Prototyping is introduced together with the most common methods, followed by the assessment of advantages and disadvantages of the new technology and its possible uses in various fields of human activity. In the experimental part of the diploma thesis was assembled and the printing parameters were set. Consequently the comparison models were printed on the 3D home printer and on professional printer Dimension uPrint. The accuracy of the printers is compared. The thesis concludes with the analysis of technical and economical parameters.
324

Konstrukce stendu pro dynamické testování protéz dolních končetin / Mechanical design of stend for lower limbs prostheses dynamic testing

Taufer, Tomáš January 2015 (has links)
This work describes design and realization of testing device for dynamic tests of foot prosthesis, made by methods of Rapid prototyping. Primary objective of design is to imitate the load on prosthesis during human gait. This task is accomplished by swing motion of prosthesis inside the frame of device during the loading of heel and tiptoe. Loading components can be removed and changed so the device can be used for different measurement like walking on an inclined plane. The result of this work is fully functional device including control program with many options to control the test. The result of test is to decide whether the foot prosthesis withstands the set of cyclic loads. The area of development of prosthesis by additive methods is young for the time being. It stands out especially with different materials, design, structure of prosthesis and fast process of production. Therefore this device can be used for testing of fatigue life of prosthesis made by additive methods.
325

Interactive Prototyping of Interactions : from Throwaway Prototypes to Takeaway Prototyping / Prototypage interactif d'interactions : des prototypes jetables au prototypage recyclable

Leiva, Germán 12 December 2018 (has links)
Le prototypage est une étape essentielle du processus de design. Pendant les premières phases du processus de conception, les designers utilisent le prototypage rapide pour explorer diverses idées. Les outils et techniques actuels de prototypage se concentrent en particulier sur des représentations papier et donc destinées à être jetées. Or, alors que ces prototypes jetables peuvent être créés rapidement, ils se prêtent mal au processus d'itération. Je propose donc de créer des outils de prototypage rapide qui puissent efficacement supporter la création d'artéfacts à la fois jetables et réutilisables pour esquisser de nouvelles interactions dans les premières phases du processus de design. La première partie porte sur le prototypage vidéo. Les designers font face à deux écueils majeurs à l'utilisation de la vidéo en design d'interaction: le temps nécessaire pour filmer et celui nécessaire pour éditer. J’ai développé VideoClipper pour aider le processus de création de vidéo. Cet outil intègre une méthode de design itérative qui encourage la planification et permet une vraie flexibilité pendant la création de prototypes. Je présente les résultats d'une étude utilisateur informelle de trois semaines avec des étudiants en design d'interaction. Les résultats suggèrent que les participants passent moins de temps à capturer et éditer avec VideoClipper qu'avec les autres outils vidéos. En revanche, ils trouvent parfois difficile de créer des stop-motions pour représenter des interactions continues et de re-filmer de nouveaux segments lorsque le design évolue. J'ai ensuite crée Montage, un outil de prototypage vidéo qui permet aux designers de progressivement augmenter leurs prototypes papier avec des maquettes numériques pour faciliter la création, la réutilisation et l'exploration d'interactions dynamiques. Montage utilise l'incrustation vidéo pour découpler l'interface du prototype de son contexte d'utilisation, permettant aux designers de les réutiliser ou de les modifier indépendamment. Je décris comment Montage améliore le prototypage vidéo en combinant la vidéo avec des maquettes numériques animées et encourage l'exploration d'autres contextes d'utilisation tout en permettant le prototypage de styles d'interaction différents. La deuxième partie porte sur l’implémentation de prototypes interactifs. Les designers et développeurs professionnels ont souvent du mal à effectuer la transition de la représentation du design à son implémentation concrète. Avec N. Maudet, j'ai mené trois études sur la conception et l'implémentation d'interactions non-conventionnelles pour comprendre l'écart entre les processus, les outils et les représentations des designers et des développeurs. Nous avons découvert que les pratiques actuelles entraînent des redondances entre le travail des designers et celui des développeurs et des divergences entre le design et son implémentation. Nous identifions trois types de problèmes: l'omission de détails critiques, l'ignorance des cas extrêmes et la non prise en compte des limitations techniques. Je propose quatre principes de design pour créer des outils qui limitent ces problèmes. Ces principes sont utilisés pour créer Enact, un environnement interactif de prototypage d'interactions tactiles. Les résultats de deux études suggèrent que Enact aide les participants à détecter plus de cas extrêmes, augmente la participation des designers et offre de nouvelles possibilités de co-création. Ces trois outils de prototypage reposent sur les mêmes principes théoriques sous-jacent: réification, polymorphisme, réutilisation et substrats d'information. De même, les outils présentés mettent en œuvre une approche du prototypage que je nomme “Takeaway Prototyping” ou prototypage recyclable. Par contraste avec les prototypes jetables, les outils pour le prototypage recyclable permettent le design par énaction et réifient des artefacts de conception pour matérialiser la progression du design. / Prototyping is essential in any design process. During the early stages, designers rely on rapid prototyping to explore ideas. Current rapid prototyping tools and techniques focus on paper representations and their disposability. However, while these throwaway prototypes are quick to create they are difficult to iterate over. I argue that rapid prototyping tools can effectively support reusable as well as throwaway artifacts for sketching interaction in early-stage design. First, I investigate tools in the context of video prototyping. Designers experience two main barriers to use video in interaction design: the time to capture and edit the video artifacts. To aid during the capturing-phase of video prototyping I created VideoClipper. This tool embodies an integrated iterative design method that rewards discipline but permits flexibility for video prototyping. The tool provides a storyboard-style overview to organize multiple videos in story Lines. VideoClipper offers editable and reusable TitleCards, video capture for steady-state and rough stop-motion filming and the ability to recombine videos in new ways for redesign. I present informal user studies with interaction design students using VideoClipper in three design courses. Results suggest that participants spend less time capturing and editing in VideoClipper than with other video tools. However, many designers find tedious to create stop-motion videos for continuous interactions and to re-shoot clips as the design evolves. Participants continuously try to reduce re-shooting by reusing backgrounds or mixing different levels of fidelity. Inspired by this behavior, I created Montage, a prototyping tool for video prototyping that lets designers progressively augment paper prototypes with digital sketches, facilitating the creation, reuse and exploration of dynamic interactions. Montage uses chroma keying to decouple the prototyped interface from its context of use, letting designers reuse or change them independently. I describe how Montage enhances video prototyping by combining video with digital animated sketches, encourages the exploration of different contexts of use, and supports prototyping of different interaction styles. Second, I investigate how early designs start being implemented into interactive prototypes. Professional designers and developers often struggle when transitioning from the illustration of the design to the actual implementation of the system. In collaboration with Nolwenn Maudet, I conducted three studies that focused on the design and implementation of custom interactions to understand the mismatches between designers' and developers' processes, tools and representations. We find that current practices induce unnecessary rework and cause discrepancies between design and implementation and we identify three recurring types of breakdowns: omitting critical details, ignoring edge cases, and disregarding technical limitations. I propose four design principles to create tools that mitigate these problems: Provide multiple viewpoints, maintain a single source of truth, reveal the invisible and support design by enaction. We apply these principles to create Enact, an interactive live environment for prototyping touch-based interactions. We introduce two studies to assess Enact and to compare designer-developer collaboration with Enact versus current tools. Results suggest that Enact helps participants detect more edge cases, increases designers' participation and provides new opportunities for co-creation. These three prototyping tools rely on the same underlying theoretical principles: reification, polymorphism, reuse, and information substrates. Also, the presented tools outline a new prototyping approach that I call "Takeaway Prototyping". In contrast to throwaway prototypes, instead of emphasizing disposability, tools for "Takeaway Prototyping" support design by enaction and reify design artifacts to materialize the lessons learned.
326

THE DEVELOPMENT OF A BIOMEMETIC DYNAMIC AIRFOIL CONTROL SYSTEM FOR FLAPPING WING MICRO AIR VEHICLES

Hauerwas, Joel Adam January 2020 (has links)
No description available.
327

Design of an Incubator Platform for Biological ISS Experiments

Hartmann, Anne Sophie January 2021 (has links)
The first European commercial research facility aboard the ISS, Space Applications Services' ICF, provides a platform for standardized plug-and-play experiments called ICE Cubes. The ICE Cubes Service provides engineering and operational support for ICE Cubes missions. In order to facilitate rapid and affordable access to space, a programmatic choice was made to mainly use COTS components in Cube design. As part of a company-internal project to develop a generic ICE Cubes platform for biological experiments, a scientific requirements document was drawn up in cooperation with interested scientists. A decision was made to aim for an experiment size of 2U (200x100x100mm). The main scientific requirements are to accommodate six reaction chambers (referred to as "wells") of standardized size; to control the temperature at well level to remain in the nominal interval of (37 +- 1)C; to accommodate a combined volume of 230ml of fluids; to provide capability to image each of the wells; and to allow for freezing of the biological payload to -80C for return to ground. The development of a prototype design for this platform, dubbed BioCube, is the topic of this thesis. Technical requirements were derived, and a functional breakdown was defined. From this, the system was partitioned into five subsystems: Thermal, Imaging/Avionics, Structure, Software, and the biological Payload. The development of the biological system is considered beyond the scope of this thesis, and the development of the software beyond that required for prototyping is left for a later stage in the design process, as significant heritage exists from previous experiments. Using a rapid prototyping approach, a prototype design for this experiment has been developed. The proposed solution utilizes a (205x104x101)mm outer structure, manufactured from aluminium and closed with two lids on the small faces. Inside, the system is split into a 3D printed avionics compartment and a payload compartment, surrounded by an air gap serving as thermal insulation. The payload compartment structure consists of aluminium, closed on one face with a transparent material through which the samples can be imaged, and provides a sealed interface connector for exchange of power and data. Both the outer structure and the payload compartment are sealed at the interfaces using O-ring seals, providing a combined two levels of biosafety containment to the payload. Manual latches on one of the lids of the outer structure allow it to be opened and the payload compartment to be extracted.The system avionics are based on a Raspberry Pi Zero with USB & Ethernet Hub and Motor Control expansion boards. A 5W silicon heating pad attached to the inside of the payload compartment provides heating, and is controlled using a PWM signal from the motor control board.Two cameras arranged in parallel are used to image wells arranged in two rows, reducing the required motion. One axis motion is implemented using a leadscrew mechanism actuated by a DC motor, driven by the motor control board. Prototyping has been performed on nearly every part of the proposed design. The leadscrew assembly has been successfully tested, and tests on a thermal model have successfully demonstrated binary thermal control achieving the nominal temperature range. Some points regarding the design remain to be defined, and more thorough verification and validation of the design remains to be performed. / La première installation de recherche commerciale européenne à bord de l'ISS, l'ICF de Space Applications Services, fournit une plateforme pour des expériences standardisées prêtes à l'emploi appelées ICE Cubes. Le ICE Cubes Service fournit un soutien technique et opérationnel pour les missions ICE Cubes. Afin de faciliter un accès rapide et abordable à l'espace, un choix programmatique a été fait d'utiliser principalement les composants COTS dans la conception des expériences. Dans le cadre d'un projet interne à l'entreprise visant à développer une plateforme ICE Cubes générique pour les expériences biologiques, un document sur les exigences scientifiques a été rédigé en coopération avec les scientifiques intéressés et il a été décidé de viser une taille d'expérience de 2 U (200x100x100 mm). Les principales exigences scientifiques sont les suivantes : accueillir 6 chambres de réaction ("puits") de la taille des puits d'une plaque à 6 puits ; contrôler la température au niveau des puits pour qu'elle reste dans l'intervalle nominal de (37 +- 1)C ; accueillir un volume combiné de 230ml de fluides ; fournir la capacité d'imager chacun des puits; et permettre la congélation de la charge utile biologique à -80\,$^\circ$C pour le retour au sol. Le développement d'un prototype de plate-forme, baptisé BioCube, est le sujet de cette thèse. Les exigences techniques ont été dérivées, et un découpage fonctionnel a été défini. A partir de là, le système a été divisé en cinq sous-systèmes : Thermique, Imagerie/Avionique, Structure, Logiciel, et la charge utile biologique. Le développement du système biologique est considéré comme hors de portée de cette thèse, et le développement du logiciel au-delà de ce qui est nécessaire pour le prototypage est laissé pour une étape ultérieure dans le processus de conception, car il existe un héritage important des expériences précédentes. En utilisant une approche de prototypage rapide, une conception de prototype pour cette expérience a été développée. La solution proposée utilise une structure extérieure de (205x104x101)mm, fabriquée en aluminium et fermée par deux couvercles sur les petites faces. À l'intérieur, le système est divisé en un compartiment avionique imprimé en 3D et un compartiment de charge utile, entourés d'une lame d'air servant d'isolation thermique. Le compartiment de la charge utile est en aluminium, fermé sur une face par un matériau transparent, à travers lequel les échantillons peuvent être imagés, et fournit un connecteur d'interface scellé pour l'échange d'énergie et de données. La structure extérieure et le compartiment de la charge utile sont scellés aux interfaces à l'aide de joints toriques, offrant ainsi deux niveaux combinés de confinement de biosécurité à la charge utile. Des loquets manuels sur l'un des couvercles de la structure extérieure permettent de l'ouvrir et d'extraire le compartiment de la charge utile.L'avionique du système est basée sur un Raspberry Pi Zero avec des cartes d'extension USB & Ethernet Hub et Motor Control.Un coussin chauffant en silicone de 5W fixé à l'intérieur du compartiment de la charge utile, assure le chauffage et est contrôlé par un signal PWM provenant de la carte de contrôle du moteur.Deux caméras disposées en parallèle sont utilisées pour imager les puits disposés sur deux rangées, ce qui réduit le mouvement nécessaire. Le mouvement sur un axe est réalisé à l'aide d'un mécanisme de vis sans fin actionné par un moteur à courant continu, piloté par la carte de commande du moteur. Le prototypage a été effectué sur presque toutes les parties de la conception proposée. L'assemblage de la vis sans fin a été testé avec succès, et les tests sur un modèle thermique ont démontré avec succès que le contrôle thermique binaire atteint la plage de température nominale. Certains points concernant la conception restent à définir, et une vérification et une validation plus approfondies de la conception restent à effectuer.
328

Using Hard Macros to Accelerate FPGA Compilation for Xilinx FPGAs

Lavin, Christopher Michael 22 January 2012 (has links) (PDF)
Field programmable gate arrays (FPGAs) offer an attractive compute platform because of their highly parallel and customizable nature in addition to the potential of being reconfigurable to any almost any desired circuit. However, compilation time (the time it takes to convert user design input into a functional implementation on the FPGA) has been a growing problem and is stifling designer productivity. This dissertation presents a new approach to FPGA compilation that more closely follows the software compilation model than that of the application specific integrated circuit (ASIC). Instead of re-compiling every module in the design for each invocation of the compilation flow, the use of pre-compiled modules that can be "linked" in the final stage of compilation are used. These pre-compiled modules are called hard macros and contain the necessary physical information to ultimately implement a module or building block of a design. By assembling hard macros together, a complete and fully functional implementation can be created within seconds. This dissertation describes the process of creating a rapid compilation flow based on hard macros for Xilinx FPGAs. First, RapidSmith, an open source framework that enabled the creation of custom CAD tools for this work is presented. Second, HMFlow, the hard macro-based rapid compilation flow is described and presented as tuned to compile Xilinx FPGA designs as fast as possible. Finally, several modifications to HMFlow are made such that it produces circuits with clock rates that run at more than 75% of Xilinx-produced implementations while compiling more than 30X faster than the Xilinx tools.
329

A Comparative Study of Strength and Stiffness of Thin-Walled Specimens Fabricated By FDM and 3D Printing Technologies

Rodrigo, Miranda 11 July 2012 (has links) (PDF)
Rapid Prototyped part failure constitutes a major issue for both RP providers and customers. When parts fail the reputation of the vendor is heavily deteriorated, customer dissatisfaction increase and replacement of the broken parts is often necessary to avoid the loss of future business. Product design teams often run into situations where Rapid Prototyped parts are not able to withstand shipping and handling and delivered broken or while demonstrating and examining the parts. When done in the face of customers this builds a perception of poor quality and lack of aptitude on the design group as well as the RP processes. The rapid advance of the RP industry and technology has led users to employ RP parts for structural applications where the need to understand in great detail and accuracy the mechanical behavior of the product and its individual components is greater than ever. Models built on Rapid Prototyping (RP) equipment are most often made from polymers which frequently have mechanical properties that are inferior to those manufactured by traditional methods such as thermoforming or injection molding. Not only are the mechanical properties of RP models typically low, they are usually, at least in thin sections, directly dependent on the section or wall thickness of the models. This dependence of strength on wall thickness makes it difficult to predict a proper wall thickness for RP models, even when nominal values of material strength are known. The purpose of this work is to present and compare measured values of tensile strength and stiffness as a function of wall thickness for three RP processes and materials. These properties will assist designers estimating adequate minimum wall thicknesses for models built by the three processes. The three RP technologies included in the scope of this research are: Z Corporation (powder with polymer binder layup), Fuse Deposition Modeling and PolyJet Layup (Objet). The findings of this study establish that tensile strength and stiffness values are dependent upon wall thickness, building orientation and direction of the applied force of specimens created with the methods in consideration. It was also determined that the correlation between thickness and strength for all processes is non-linear. Due to these results a single tensile strength and modulus value for each material and all wall thicknesses do not accurately represent their behavior. However, these results will allow a designer to understand the relationship between the wall thickness and using the data provided in this work be able to model and then fabricate adequate 3D prototypes.
330

Fuzzy Robots: Utopian Ideals, The Immortalization Of Youth, And The Innocence Of Childhood.

Caps, Elizabeth 01 January 2009 (has links)
Ideals, aesthetics, forms, and concepts have resurfaced in various cultures throughout time. I am interested in the idea of the recurring themes that exist in the collective unconscious. I create monolithic figures that exhibit these archetypal qualities. Heavily influenced by film, animation, video games, and contemporary art, I create figures and paintings that are manifestations of my subconscious. These manifestations personify utopian ideals, the immortalization of youth, and the innocence of childhood.

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