158 research outputs found

    What is the Avatar? Fiction and Embodiment in Avatar-Based Singleplayer Computer Games: Revised and Commented Edition

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    What are the characteristic features of avatar-based singleplayer videogames, from Super Mario Bros. to Grand Theft Auto? The author examines this question with a particular focus on issues of fictionality and realism, and their relation to cinema and Virtual Reality. Through close-up analysis and philosophical discussion, the author argues that avatar-based gaming is a distinctive and dominant form of virtual self-embodiment in digital culture. This book is a revised edition of Rune Klevjer's pioneering work from 2007, featuring a new introduction by the author and afterword by Stephan Günzel, Jörg Sternagel, and Dieter Mersch

    Advanced Augmented Reality Telestration Techniques With Applications In Laparoscopic And Robotic Surgery

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    The art of teaching laparoscopic or robotic surgery currently has a primary reliance on an expert surgeon tutoring a student during a live surgery. During these operations, surgeons are viewing the inside of the body through a manipulatable camera. Due to the viewpoint translation and narrow field of view, these techniques have a substantial learning curve in order to gain the mastery necessary to operate safely. In addition to moving and rotating the camera, the surgeon must also manipulate tools inserted into the body. These tools are only visible on camera, and pass through a pivot point on the body that, in non-robotic cases, reverses their directions of motion when compared to the surgeon\u27s hands. These difficulties spurred on this dissertation. The main hypothesis of this research is that advanced augmented reality techniques can improve telementoring for use between expert surgeons and surgical students. In addition, it can provide a better method of communication between surgeon and camera operator. This research has two specific aims: (1) Create a head-mounted direction of focus indicator to provide non-verbal assistance for camera operation. A system was created to track where the surgeon is looking and provides augmented reality cues to the camera operator explaining the camera desires of the surgeon. (2) Create a hardware / software environment for the tracking of a camera and an object, allowing for the display of registered pre-operative imaging that can be manipulated during the procedure. A set of augmented reality cues describing the translation, zoom, and roll of a laparoscopic camera were developed for Aim 1. An experiment was run to determine whether using augmented reality cues or verbal cues was faster and more efficient at acquiring targets on camera at a specific location, zoom level, and roll angle. The study found that in all instances, the augmented reality cues resulted in faster completion of the task with better economy of movement than with the verbal cues. A large number of environmentally registered augmented reality telestration and visualization features were added to a hardware / software platform for Aim 2. The implemented manipulation of pre-operative imaging and the ability to provide different types of registered annotation in the working environment has provided numerous examples of improved utility in telementoring systems. The results of this work provide potential improvements to the utilization of pre-operative imaging in the operating room, to the effectiveness of telementoring as a surgical teaching tool, and to the effective communication between the surgeon and the camera operator in laparoscopic surgery

    What is the Avatar?

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    What are the characteristic features of avatar-based singleplayer videogames, from Super Mario Bros. to Grand Theft Auto? Rune Klevjer examines this question with a particular focus on issues of fictionality and realism, and their relation to cinema and Virtual Reality. Through close-up analysis and philosophical discussion, Klevjer argues that avatar-based gaming is a distinctive and dominant form of virtual self-embodiment in digital culture. This book is a revised edition of Rune Klevjer's pioneering work from 2007, featuring a new introduction by the author and afterword by Stephan Günzel, Jörg Sternagel, and Dieter Mersch

    MULTIDISCIPLINARY TECHNIQUES FOR THE SIMULATION OF THE CONTACT BETWEEN THE FOOT AND THE SHOE UPPER IN GAIT: VIRTUAL REALITY, COMPUTATIONAL BIOMECHANICS, AND ARTIFICIAL NEURAL NETWORKS

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    Esta Tesis propone el uso de técnicas multidisciplinares como una alternativa viable a los procedimientos actuales de evaluación del calzado los cuales, normalmente, consumen muchos recursos humanos y técnicos. Estas técnicas son Realidad Virtual, Biomecánica Computacional y Redes Neuronales Artificiales. El marco de esta tesis es el análisis virtual del confort mecánico en el calzado, es decir, el análisis de las presiones de confort en el calzado y su principal objetivo es predecir las presiones ejercidas por el zapato sobre la superficie del pie al caminar mediante la simulación del contacto en esta interfaz. En particular, en esta tesis se ha desarrollado una aplicación software que usa el Método de los Elementos Finitos para simular la deformación del calzado. Se ha desarrollado un modelo preliminar que describe el comportamiento del corte del calzado, se ha implementado un proceso automático para el ajuste pie-zapato y se ha presentado una metodología para obtener una animación genérica del paso de cada individuo. Además, y con el fin de mejorar la aplicación desarrollada, se han propuesto nuevos modelos para simular el comportamiento del corte del calzado al caminar. Por otro lado, las Redes Neuronales Artificiales han sido aplicadas en esta tesis a la predicción de la fuerza ejercida por una esfera, que simulando un hueso, empuja a una muestra de material. Además, también han sido utilizadas para predecir las presiones ejercidas por el corte del calzado sobre la superficie del pie (presiones dorsales) en un paso completo. Las principales contribuciones de esta tesis son: el desarrollo de un innovador simulador que permitirá a los fabricantes de calzado realizar evaluaciones virtuales de las características de sus diseños sin tener que construir el prototipo real, y el desarrollo de una también innovadora herramienta que les permitirá predecir las presiones dorsales ejercidas por el calzado sobre la superficie del pie al caminar.Rupérez Moreno, MJ. (2011). MULTIDISCIPLINARY TECHNIQUES FOR THE SIMULATION OF THE CONTACT BETWEEN THE FOOT AND THE SHOE UPPER IN GAIT: VIRTUAL REALITY, COMPUTATIONAL BIOMECHANICS, AND ARTIFICIAL NEURAL NETWORKS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/11235Palanci

    Haptic Interface for the Simulation of Endovascular Interventions

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    Endovascular interventions are minimally invasive surgical procedures that are performed to diagnose and treat vascular diseases. These interventions use a combination of long and flexible instruments known as guidewire and catheter. A popular method of developing the skills required to manipulate the instruments successfully is through the use of virtual reality (VR) simulators. However, the interfaces of current VR simulators have several shortcomings due to limitations in the instrument tracking and haptic feedback systems design. A major challenge of developing physics-based training simulations of endovascular interventional procedures is to unobtrusively access the central, co-axial guidewire for tracking and haptics. This work sets out to explore the state of the art, to identify and develop novel solutions to this concentric occlusion problem, and to perform a validation of a proof of concept prototype. This multi port haptic interface prototype has been integrated with a 3-D virtual environment and features novel instrument tracking and haptic feedback actuation systems. The former involves the use of an optical sensor to detect guidewire movements through a clear catheter, whereas the latter utilises the placement of a customised electromagnetic actuator within the catheter hub. During the proof of concept validation process, both systems received positive reviews. Whilst the haptic interface prototype designed in this work has met the original objectives, there are still important aspects which need to be addressed to improve its content and face validity. With further development, the prototype has the potential to evolve and become a significant improvement over the haptic interfaces that exist today.Open Acces

    Experimental evaluation of interaction design in virtual reality

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    Desktop Virtual Reality (VR) is a simple and affordable way to implement VR technology into an organisation. With PC technology developing at a phenomenal pace fast processor speeds enable the relatively easy development of visually impressive Virtual Environments (VEs) that can be used with familiar desktop PCs for novice and expert end users alike. A need had consequently evolved to ensure that VE development is structured so that VEs can be visually impressive, usable and effective for their purpose. Interaction between the user and the VE is a distinguishing feature of VR but the importance of interaction on the effectiveness of the VE has been little explored, in particular how to measure that effectiveness with a view to providing guidance to VE developers in this case for training applications using the familiar and affordable desktop medium. The use of VR as a training tool has been widely investigated and implemented in both research and industry. Through experimentation this thesis reviews the design of effective interaction, primarily with the design of selection hotspots (cued objects within the VE designed to prompt the user to select that object) and the importance of implementing task guided interaction into the user’s experience with the VR system. Five experiments were performed to examine the appropriate design of selection hotspots and the importance on the inclusion of a task to the effectiveness of desktop VR training. The initial experiment examined the importance of the user's ability to select within the VE, control their own navigation and the influence of visual realism on the VE’s effectiveness as a training tool. The second experiment explored the importance of the user performing a task on the VE's effectiveness and the effectiveness of various selection hotspot cue designs. The third experiment examined influencing factors on the recall of non-task related aspects of the VE. Experiment four examined the effectiveness of selection hotspot cues when they are no longer congruous to the surrounding VE context and the final experiment investigated if participants perceived and recognised the cued objects or were merely responding to the cue and the influence of the inclusion of cues and their design. Effectiveness was measured using the recall of aspects of the VE by the user and measures of usability, presence and enjoyment. Main findings were that the use of the same incongruous interaction hot spot cues throughout the VE to prompt the selection of specific points within the VE were most effective and using task directed interaction improved task related recall but significantly reduced selection within the VE. Selection significantly increased recall when in a non-task directed VE. With the application of these findings it is possible that designers can produce more effective VEs for their purpose, in this context as a training VE on a desktop VE system

    The feet in human--computer interaction: a survey of foot-based interaction

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    Foot-operated computer interfaces have been studied since the inception of human--computer interaction. Thanks to the miniaturisation and decreasing cost of sensing technology, there is an increasing interest exploring this alternative input modality, but no comprehensive overview of its research landscape. In this survey, we review the literature on interfaces operated by the lower limbs. We investigate the characteristics of users and how they affect the design of such interfaces. Next, we describe and analyse foot-based research prototypes and commercial systems in how they capture input and provide feedback. We then analyse the interactions between users and systems from the perspective of the actions performed in these interactions. Finally, we discuss our findings and use them to identify open questions and directions for future research

    Improving Chemical Plant Safety Training Using Virtual Reality

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    The chemical engineering industry often requires people to work in hazardous environments and to operate complicated equipment which often limits the type of training that be carried out on site. The daily job of chemical plant operators is becoming more demanding due to the increasing plant complexity together with increasing requirements on plant safety, production capacity, product quality and cost effectiveness. The importance of designing systems and environments that are as safe as possible to educate and train personnel is vital for the chemical process industries. Virtual reality offers the potential to expose personnel to hazardous situations in a safe, highly visual and interactive manner. Virtual reality has been proposed as a technological breakthrough that holds the power to facilitate learning. The ability to visualise complex and dynamic systems involving personnel, equipment and layouts during any real operation is a potential advantage of such an approach. Virtual reality and multimedia training is commonly used in many industries, aiding understanding and memory retention and creating a more interactive learning experience. Four desktop virtual reality training environments were developed for this research which highlighted issues related to chemical process dynamic simulation and plant safety. The pump training system is a virtual reality environment, which was built using the SAFE-VR virtual engine, to train personnel to operate two centrifugal pumps. The virtual hazard spotting exercise focuses on improving the users' safety awareness of electrical and occupational hygiene hazards. The virtual boiler plant is a complicated and high detailed virtual training environment, which is characterised by its flexibility and by a real time dynamic simulation of the steam generation chemical process. The virtual flooding and gas absorption experiment was based on an undergraduate laboratory experiment for the Chemical Engineering degree course at the University of Nottingham, focusing primarily on training and safety issues of students using the equipment. The dynamic features of the virtual absorption column simulation give high level of realism in the virtual environment

    DESIGNING AUGMENTED SPORTS: TEAM GAMES WITH A BALL

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