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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.
21

Design and Testing of an Electrostatic Actuator with Dual-Electrodes for Large Touch Display Applications

Mason, Taylor William 26 July 2021 (has links)
No description available.
22

An Ergonomics Investigation of the Application of Virtual Reality on Training for a Precision Task

Bales, Delaney M 01 June 2017 (has links)
Virtual reality is rapidly expanding its capabilities and accessibility to consumers. The application of virtual reality in training for precision tasks has been limited to specialized equipment such as a haptic glove or a haptic stylus, but not studied for handheld controllers in consumer-grade systems such as the HTC Vive. A straight-line precision steadiness task was adopted in virtual reality to emulate basic linear movements in industrial operations and disability rehabilitation. This study collected the total time and the error time for the straight-line task in both virtual reality and a physical control experiment for 48 participants. The task was performed at four different gap widths, 4mm, 5mm, 6mm, and 7mm, to see the effects of virtual reality at different levels of precision. Average error ratios were then calculated and analyzed for strong associations to various factors. The results indicated that a combination of Environment x Gap Width factors significantly affected average error ratios, with a p-value of 0.000. This human factors study also collected participants’ ratings of user experience dimensions, such as difficulty, comfort, strain, reliability, and effectiveness, for both physical and virtual environments in a questionnaire. The results indicate that the ratings for difficulty, reliability, and effectiveness were significantly different, with virtual reality rating consistently rating worse than the physical environment. An analysis of questionnaire responses indicates a significant association of overall environment preference (physical or virtual) with performance data, with a p-value of 0.027. In general, virtual reality yielded higher error among participants. As the difficulty of the task increased, the performance in virtual reality degraded significantly. Virtual reality has great potential for a variety of precision applications, but the technology in consumer-grade hardware must improve significantly to enable these applications. Virtual reality is difficult to implement without previous experience or specialized knowledge in programming, which makes the technology currently inaccessible for many people. Future work is needed to investigate a larger variety of precision tasks and movements to expand the body of knowledge of virtual reality applications for training purposes.
23

MULTIMODAL VIRTUAL LEARNING ENVIRONMENTS: THE EFFECTS OF VISUO-HAPTIC SIMULATIONS ON CONCEPTUAL LEARNING

Mayari Serrano Anazco (8790932) 03 May 2020 (has links)
<p>Presently, it is possible to use virtual learning environments for simulating abstract and/or complex scientific concepts. Multimodal Virtual Learning Environments use multiple sensory stimuli, including haptic feedback, in the representation of concepts. Past research</p> <p>on the utilization of haptics for learning has shown inconsistent results when gains in conceptual knowledge had been assessed. This research focused on two abstract phenomena</p> <p>Electricity and Magnetism and Buoyancy. These abstract concepts were experienced by students using either visual, visuo-haptic, or hands-on learning activities. Embodied</p> <p>Cognition Theory was used as a for the implementation of the learning environments. Both phenomena were assessed using qualitative and quantitative data analysis techniques.</p> <p>Results suggested that haptic, visual, and physical modalities affected positively the acquisition of conceptual knowledge of both concepts.</p>
24

Effekten av audio-haptisk feedback på simulerad körning

Modin, Sara, Garrido Velasquez, Simon January 2023 (has links)
Den teknologiska utvecklingen går i full fart i dagens samhälle och detta påverkar även utvecklandet av utbildningar och dess tillvägagångssätt. Simulatorer och simulerad inlärning tar allt mer plats inom allt från medicinsk utbildning till golfsport och har länge använts inom pilotutbildning. Implementeringen av simulatorer kan i framtiden komma att ersätta stora delar av den traditionella utbildningen då simulatorerna blir allt mer effektiva. Detta är särskilt aktuellt inom farliga och mer komplicerade situationer där felsteg kan vara kritiska. Ett exempel där kritiska tillfällen kan uppstå är inom bilkörning och körsimulatorer har därför börjat bli ett allt vanligare komplement hos trafikskolor. Denna studie hade därför som mål att undersöka körförmågan och körsäkerheten hos nybörjarförare i en simulator, för att se om auditiv och haptisk feedback har någon effekt på dessa. Till studien rekryterades 12 deltagare av låg körerfarenhet, varav fem kvinnor och sju män. Studien var experimentell med inomgruppsdesign där hälften av deltagarna började köra utan feedback medan andra halvan började med feedback. Deltagarna bytte sedan betingelse. Feedback under körning visade ingen signifikant påverkan av körförmåga eller körsäkerhet. Detta kan bero på det låga antalet deltagare då de sammanlagda avvikelserna var högre vid avsaknad av feedback. Detta resultat antyder även att nya förare inte använder sig av audio-haptiska ledtrådar i lika stor utsträckning som mer erfarna förare. / Technological advancement is traveling at high speeds in today's society and this has had a big impact on education and its approaches. Simulators and simulated learning have become more prevalent in everything from medical training to golf sports and have been used for a long time in the aviation field by training pilots. The implementation of simulators could come to replace big parts of the traditional approach in the educational field because of their high rise in effectiveness. Simulators are especially topical in dangerous and more complex situations where mishaps could be critical. One example would be driving, and driving simulators seems to be on the rise in traffic education. This study had as a goal to examine driving skills and safety in novice drivers in a driving simulator to see if audio and haptic feedback had an impact. 12 participants with little to no driving experience were recruited, five women and seven men. The study was an experiment of within-group design where half of the participants started driving with feedback, while the other half started driving without feedback and then they switched condition. Feedback during driving showed no significant effects on driving skill or safety. This could be due to the low sample size because even though there was no significant effect measured, there was a bigger amount of deviations in the no feedback test group. The results suggest that novice drivers don’t use audio haptic clues as part of their driving as much as experienced drivers do.
25

Simulating moral actions: An investigation of personal force in virtual moral dilemmas

Francis, Kathryn B., Terbeck, S., Briazu, R.A., Haines, A., Gummerum, M., Ganis, G., Howard, I.S. 24 October 2017 (has links)
Yes / Advances in Virtual Reality (VR) technologies allow the investigation of simulated moral actions in visually immersive environments. Using a robotic manipulandum and an interactive sculpture, we now also incorporate realistic haptic feedback into virtual moral simulations. In two experiments, we found that participants responded with greater utilitarian actions in virtual and haptic environments when compared to traditional questionnaire assessments of moral judgments. In experiment one, when incorporating a robotic manipulandum, we found that the physical power of simulated utilitarian responses (calculated as the product of force and speed) was predicted by individual levels of psychopathy. In experiment two, which integrated an interactive and life-like sculpture of a human into a VR simulation, greater utilitarian actions continued to be observed. Together, these results support a disparity between simulated moral action and moral judgment. Overall this research combines state-of-the-art virtual reality, robotic movement simulations, and realistic human sculptures, to enhance moral paradigms that are often contextually impoverished. As such, this combination provides a better assessment of simulated moral action, and illustrates the embodied nature of morally-relevant actions. / Plymouth University and Seventh Framework Programme (FP7-PEOPLE-2013-ITN-604764)
26

Applied Virtual Reality Training for Scalable Skill Acquisition in Hand Tool Focused Trades

Levi Andrew Erickson (15339334) 22 April 2023 (has links)
<p> Skilled trades are in demand across many industries and many countries. Skilled trades refer to occupations that require training and proficiency in a specialized field, such as weld?ing, carpentry, or mechanics. The challenge is upskilling workers to become suited for these positions. One way training might be made more accessible is through low cost VR applica?tions as they can provide a ’learn by doing’ modality that is effective for learning motor skills, and also engaging for providing a holistic training experience. In this thesis, design guide?lines and a methodology for creating training programs that target hand tool based skills are laid out, tested, and refined for future usage. Working with content experts, a learning plan was developed via the backward design methodology, evaluated in a user study, and then applied to a second use case. The results of the user study showed that those who trained with VR were able to perform the prescribed task more quickly and with less mistakes. The implication of the second use case is that the established guidelines are versatile enough to be applied to other industries and simple enough to adapt industry specific knowledge to. The hope is that this work can help bridge the gap between the theoretical possibilities of VR training, effective training methodology, and real world application. </p>
27

Usage of tactile feedback to aid cooperative object manipulation in virtual environments

Oliveira, Thomas Volpato de 23 August 2017 (has links)
Submitted by PPG Ci?ncia da Computa??o (ppgcc@pucrs.br) on 2018-07-26T19:57:26Z No. of bitstreams: 1 THOMAS VOLPATO DE OLIVEIRA_DIS.pdf: 2340160 bytes, checksum: a77fc7c024da22cb1ea18eec69501d7e (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-08-02T12:22:16Z (GMT) No. of bitstreams: 1 THOMAS VOLPATO DE OLIVEIRA_DIS.pdf: 2340160 bytes, checksum: a77fc7c024da22cb1ea18eec69501d7e (MD5) / Made available in DSpace on 2018-08-02T12:38:03Z (GMT). No. of bitstreams: 1 THOMAS VOLPATO DE OLIVEIRA_DIS.pdf: 2340160 bytes, checksum: a77fc7c024da22cb1ea18eec69501d7e (MD5) Previous issue date: 2017-08-23 / Realidade virtual ? uma tecnologia que permite aos seus usu?rios visualizar e interagir com ambientes virtuais (AV) 3D em tempo real. Um ambiente virtual colaborativo (AVC) ? um tipo de AV que permite que dois ou mais usu?rios estejam juntos no mesmo ambiente virtual. Ambientes virtuais colaborativos t?m algumas dificuldades que AV comuns n?o t?m. Por exemplo, diferentes t?cnicas s?o necess?rias a fim de permitir a dois usu?rios a manipula??o (mover ou girar) conjunta de um objeto virtual. Algumas dessas t?cnicas podem levar os usu?rios a realizarem movimentos n?o naturais. Este trabalho avalia o retorno h?ptico para deixar os usu?rios cientes de movimentos errados durante a manipula??o colaborativa de objetos. A t?cnica SkeweR foi utilizada como teste. Esta t?cnica ? baseada em crushing points, onde os usu?rios pegam o objeto pela primeira vez para simultaneamente mover e girar o objeto. Uma vez que os usu?rios mant?m a posi??o da m?o sobre o crushing point durante a manipula??o do objeto, a intera??o se torna mais natural, no sentido de que se torna mais similar ao processo real de segurar um objeto. Entretanto, devido ? falta de restri??es f?sicas de movimento, frequentemente, durante a intera??o, a m?o do usu?rio se move para fora do crushing point. Para solucionar este problema, este trabalho prop?e o uso de retorno t?til para informar os usu?rios sobre a dist?ncia entre a posi??o da m?o e o crushing point. O retorno t?til ? fornecido por um minimotor de vibra??o preso no polegar do usu?rio. Para validar o m?todo, fez-se um estudo com usu?rios em que estes deveriam realizar a manipula??o 3D de um objeto virtual. Este objeto precisava ser transladado e girado atrav?s de um caminho virtual ao longo de um fio virtual, do in?cio deste at? o fim. Durante a intera??o, os usu?rios manipularam um rastreador de posi??o com tr?s graus de liberdade (3DOF) e deveriam manter a posi??o do rastreador na mesma posi??o do crushing point. Durante as rodadas do experimento, os participantes testaram tr?s modalidades de intera??o: sem nenhum retorno, com retorno visual e com retorno t?til. O resultado dos testes mostrou que usu?rios realizaram manipula??es mais naturais quando estavam usando o retorno t?til. / Virtual reality is a technology that allows users to view and interact with a 3D virtual environment (VE) in real time. A collaborative virtual environment (CVE) is a type of VE that allows two or more users to be in the same virtual environment together. Collaborative virtual environments have some issues that simple VEs do not have. For example, different techniques are required in order to allow two users to manipulate (move or rotate) a virtual object together. Some of these techniques can lead users to do unnatural movements. This study evaluates haptic feedback to let users aware of wrong movements during a cooperative object manipulation. The SkeweR technique was used as a testbed. This technique is based on the use of crushing points, where the users grab the object for the first time, to simultaneously move/rotate an object. Once the users have their hands positioned on the crushing point during the object manipulation, the interaction becomes more natural, in the sense that it is more similar to the real process. However, due to the lack of any physical constraint to the users? movements, it is often noticed that the users? hands move away from the crushing point during the interaction. To solve this problem, this work proposes the usage of tactile feedback to inform the user about the distance between his hand and the crushing point. The tactile feedback is provided by a vibration micromotor attached to the user?s thumb. To validate the method, a user study based on the 3D manipulation of a virtual object was performed. The virtual object had to be translated and rotated through a virtual path along a virtual wire, from the beginning to the end of it. During the interaction, users manipulated a three degrees of freedom (3DOF) position tracker and were requested to keep this tracker in the same position of the crushing point. During the trials, the participants used three modalities of interaction: without any feedback, with a visual feedback and with tactile feedback. Results showed that the users do more natural manipulations when using tactile feedback.
28

Haptic Milling Simulation in Six Degrees-of-Freedom : With Application to Surgery in Stiff Tissue

Eriksson, Magnus G. January 2012 (has links)
The research presented in this thesis describes a substantial part of the design of a prototypical surgical training simulator. The results are intended to be applied in future simulators used to educate and train surgeons for bone milling operations. In earlier work we have developed a haptic bone milling surgery simulator prototype based on three degrees-of-freedom force feedback. The contributions presented here constitute an extension to that work by further developing the haptic algorithms to enable six degrees-of-freedom (6-DOF) haptic feedback. Such feedback is crucial for a realistic haptic experience when interacting in a more complex virtual environment, particularly in milling applications.The main contributions of this thesis are:The developed 6-DOF haptic algorithm is based on the work done by Barbic and James, but differs in that the algorithm is modified and optimized for milling applications. The new algorithm handles the challenging problem of real-time rendering of volume data changes due to material removal, while fulfilling the requirements on stability and smoothness of the kind of haptic applications that we approach. The material removal algorithm and the graphic rendering presented here are based on the earlier research. The new 6-DOF haptic milling algorithm is characterized by voxel-based collision detection, penalty-based and constraint-based haptic feedback, and by using a virtual coupling for stable interaction.Milling a hole in an object in the virtual environment or dragging the virtual tool along the surface of a virtual object shall generate realistic contact force and torque in the correct directions. These are important requirements for a bone milling simulator to be used as a future training tool in the curriculum of surgeons. The goal of this thesis is to present and state the quality of a newly developed 6-DOF haptic milling algorithm. The quality of the algorithm is confirmed through a verification test and a face validity study performed in collaboration with the Division of Orthopedics at the Karolinska University Hospital. In a simulator prototype, the haptic algorithm is implemented together with a new 6-DOF haptic device based on parallel kinematics. This device is developed with workspace, transparency and stiffness characteristics specifically adapted to the particular procedure. This thesis is focuses on the 6-DOF haptic algorithm. / QC 20120226
29

Virtual Assembly and Disassembly Analysis: An Exploration into Virtual Object Interactions and Haptic Feedback

Coutee, Adam S. 07 June 2004 (has links)
In recent years, researchers have developed virtual environments, which allow more realistic human-computer interactions and have become increasingly popular for engineering applications such as computer-aided design and process evaluation. For instance, the demand for product service, remanufacture, and recycling has forced companies to consider ease of assembly and disassembly during the design phase of their products. Evaluating these processes in a virtual environment during the early stages of design not only increases the impact of design modifications on the final product, but also eliminates the time, cost, and material associated with the construction of physical prototypes. Although numerous virtual environments for assembly analysis exist or are under development, many provide only visual feedback. A real-time haptic simulation test bed for the analysis of assembly and disassembly operations has been developed, providing the designer with force and tactile feedback in addition to traditional visual feedback. The development such a simulation requires the modeling of collisions between virtual objects, which is a computationally expensive process. Also, the demands of a real-time simulation incorporating haptic feedback introduce additional complications for reliable collision detection. Therefore, the first objective of this work was to discover ways in which current collision detection libraries can be improved or supplemented to create more robust interaction between virtual objects. Using the simulation as a test bed, studies were then conducted to determine the potential usefulness of haptic feedback for analysis of assembly and disassembly operations. The following significant contributions were accomplished: (1) a simulation combining the strengths of an impulse-based simulation with a supplemental constraint maintenance scheme for modeling object interactions, (2) a toolkit of supplemental techniques to support object interactions in situations where collision detection algorithms commonly fail, (3) a haptic assembly and disassembly simulation useful for experimentation, and (4) results from a series of five experimental user studies with the focus of determining the effectiveness of haptic feedback in such a simulation. Additional contributions include knowledge of the usability and functionality of current collision detection libraries, the limitations of haptic feedback devices, and feedback from experimental subjects regarding their comfort and overall satisfaction with the simulation.
30

Haptic and visual simulation of material cutting process : a study focused on bone surgery and the use of simulators for education and training

Eriksson, Magnus G. January 2006 (has links)
<p>A prototype of a haptic and virtual reality simulator has been developed for simulation of the bone milling and material removal process occurring in several operations, e.g. temporal bone surgery or dental milling. The milling phase of an operation is difficult, safety critical and very time consuming. Reduction of operation time by only a few percent would in the long run save society large expenses. In order to reduce operation time and to provide surgeons with an invaluable practicing environment, this licentiate thesis discusses the introduction of a simulator system to be used in both surgeon curriculum and in close connection to the actual operations.</p><p>The virtual reality and haptic feedback topics still constitute a young and unexplored area. It has only been active for about 10-15 years for medical applications. High risk training on real patients and the change from open surgery to endoscopic procedures have enforced the introduction of haptic and virtual reality simulators for training of surgeons. Increased computer power and the similarity to the successful aviation simulators also motivate to start using simulators for training of surgical skills.</p><p>The research focus has been twofold: 1) To develop a well working VR-system for realistic graphical representation of the skull itself including the changes resulting from milling, and 2) to find an efficient algorithm for haptic feedback to mimic the milling procedure using the volumetric Computer Tomography (CT) data of the skull. The developed haptic algorithm has been verified and tested in the simulator. The visualization of the milling process is rendered at a graphical frame rate of 30 Hz and the haptic rendering loop is updated at 1000 Hz. Test results show that the real-time demands are fulfilled. The visual and haptic implementations have been the two major steps to reach the over all goal with this research project.</p><p>A survey study is also included where the use of VR and haptic simulators in the surgical curriculum is investigated. The study starts with a historical perspective of the VR and haptic topics and is built up by answering different questions related to this topic and the implementation of simulators at the medical centres. The questions are of general concern for those developing surgical VR and haptic simulators.</p><p>Suggested future work includes modelling, development and validation of the haptic forces occurring in the milling process and, based on this, implementation in the simulator system. Also, further development of the simulator should be done in close cooperation with surgeons in order to get appropriate feedback for further improvements of the functionality and performance of the simulator.</p>

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