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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.
231

The Newtonian Architecture for Virtual Landscapes : an architecture, model and implementation

Wedlake, Martine Bruce 08 December 2017 (has links)
There is much research in the literature regarding the construction of distributed virtual reality implementations. After evaluating some well-known virtual reality systems, it was determined that several problems exist that need to be solved. In particular: network efficiency, object distribution and coherency, inadequate system resource management, and overall performance. In order to properly address these issues, a holistic design approach is taken. The entire system is examined, rather than focusing on a specific problem area (such as the human-computer interface). The major component of this work, the Newtonian Architecture for Virtual Landscapes (NAVL), is presented to respond to the problems areas discovered. Highlights of the architecture include: (1) A distributed client/server network that addressed the networking issues. (2) Autonomous objects encapsulate control and object state into a single entity. Using autonomous objects avoids lengthy synchronization processes (e.g., full database locking). (3) ForceLets, a novel synchronization method, minimize the network bandwidth required to keep an object synchronized at remote locations. In addition, ForceLets provide much improved synchronization of the object at the remote locations in the presence of network lag. Implementation details of the NAVL prototype are also presented. The implementation consists of an object simulation and execution unit, rendering and collision detection unit, and network subsystem and protocols. An evaluation of the NAVL system architecture examines the efficiency of the key architectural components: (1) A bandwidth and latency analysis examines the efficiency of the distributed client/server network. (2) The object distribution and coherency components are tested directly from the prototype. Profiles of actual prototype execution are used to show the efficiency gains of the ForceLet approach as compared to the commonly used stream-of-data coherency mechanism. (3) The rendering and collision detection unit is tested by examining the effects on CPU utilization and frame rate with increases in the number of virtual objects. / Graduate
232

Using virtual reality to monitor and control an industrial robot via the Internet

Vermeulen, Heinrich January 2001 (has links)
Manufacturing processes may be modeled in various ways, including 3D modeling. There is a need to visualise, control and monitor manufacturing processes remotely via the Internet. Virtual Reality (VR) can be described as the science of integrating man with information. It is based on three distinct environments: three-dimensional, interactive and computer-generated. VR has come to the Internet in the form of VR modeling. The evolution of Web technologies in recent years has enabled the use of VR modeling for visualisation of manufacturing processes. The VR modeling language (VRML), which has become the standard for transmitting 3D virtual worlds across the Internet, can be used to control and monitor manufacturing processes visually. A 3D model of a manufacturing process, specifically an industrial robot arm, was created for this project. This model was successfully linked to the industrial robot that it represents in order to control and monitor the robot’s actions remotely via the Internet using Web technologies. This dissertation proves the viablity of using Virtual Reality to effectively visualise, monitor and control an industrial robot via the Internet. It also describes the methodology that was followed in modeling the industrial robot arm in VRML as well as linking the model to the real world application.
233

Integrated haptic interface : tactile and force feedback for improved realism in VR and telepresence applications

Tsagarakis, N. G. January 2000 (has links)
Virtual Reality is a powerful tool for training, simulation, and computer aided design. The sensation of being in a real environment, while interacting with VR simulation is usually referred as sense of presence or sense of immersion. In most of the current applications the focus has been in providing a good visual and sound feedback to the user. However, the lack of mechanoreception/touch and proprioception/force feedback, or in other words, the impossibility of really touching the virtual objects makes the interaction unreal and more difficult. The rapid advances in VR and the development of techniques such as virtual medicine, virtual training and virtual prototyping have highlighted the lack of an effective input/feedback interface in these technologies and this led to research activity in all aspects of input and feedback technology related to touch/force sensation and reflection. This work presents the development of a generic integrated haptic (touch/force) feedback interface for use in VR and telepresence applications. The interface presented here consists of a 7 DOF input control/force feedback exoskeleton and a multi-functional input control/touch feedback glove interface. The arm exoskeleton monitors the motions of the human arm and feed back force sensations using ultra light weight pneumatic Muscle Actuators (pMA) to obtain high power weight outputs in a light comfortable and inherently safe structure. The glove interface monitors the motions of the hand and feed back touch sensations such as contact pressure, surface texture and temperature. These hardware systems have been integrated together and have been interfaced with a virtual reality system to permit exploration and testing of interactions with virtual environments. It is believed that the use of the system in VR, particularly, in all design and rapid prototyping applications will provide enhanced performance and will augment the design-production process.
234

Erfahrungen zur Nutzung von Mixed und Virtual Reality im Lehralltag an der HTW Dresden

Göbel, Gunther, Sonntag, Ralph 28 March 2018 (has links) (PDF)
Der Einsatz von immersiven Systemen, also Virtual Reality (VR), Augmented Reality (AR) und Mixed Reality (MR) Systemen in der Lehre ist naheliegend. Eigene interaktive Erfahrung einer Tätigkeit ist immer einer reinen rezeptiven Beobachtung bzw. verbalen Erläuterung vorzuziehen. Trotzdem ist heutige Lehre selbst in Praktika und Übungen zum sehr großen Teil passiv, die selbständige Umsetzung, etwa das Bedienen einer Anlage oder die eigenständige Synthese einer Chemikalie, können aus Gründen der Zeit, Verfügbarkeit, Sicherheitsbedenken und Kostengründen oft nur selten eingesetzt werden. Dem Einsatz o.g. neuer immersiven Technologien stand bisher nicht nur der erhebliche Aufwand zur Erstellung entsprechender Simulationen gegenüber. Vor allem aber auch der Hardwareaufwand bei gleichzeitigem nicht optimalem Grad an Immersivität ließ kaum Möglichkeiten offen. Jeden Studenten einzeln ausreichend Zeit in einer teuren und großen Cave-Umgebung zu ermöglichen, damit dieser virtuell technische Anlagen bedient, ist für größere Studentenzahlen untauglich. [... aus der Einleitung]
235

Parallel implementation of a virtual reality system on a transputer architecture

Bangay, Shaun Douglas 11 October 2012 (has links)
A Virtual Reality is a computer model of an environment, actual or imagined, presented to a user in as realistic a fashion as possible. Stereo goggles may be used to provide the user with a view of the modelled environment from within the environment, while a data-glove is used to interact with the environment. To simulate reality on a computer, the machine has to produce realistic images rapidly. Such a requirement usually necessitates expensive equipment. This thesis presents an implementation of a virtual reality system on a transputer architecture. The system is general, and is intended to provide support for the development of various virtual environments. The three main components of the system are the output device drivers, the input device drivers, and the virtual world kernel. This last component is responsible for the simulation of the virtual world. The rendering system is described in detail. Various methods for implementing the components of the graphics pipeline are discussed. These are then generalised to make use of the facilities provided by the transputer processor for parallel processing. A number of different decomposition techniques are implemented and compared. The emphasis in this section is on the speed at which the world can be rendered, and the interaction latency involved. In the best case, where almost linear speedup is obtained, a world containing over 250 polygons is rendered at 32 frames/second. The bandwidth of the transputer links is the major factor limiting speedup. A description is given of an input device driver which makes use of a powerglove. Techniques for overcoming the limitations of this device, and for interacting with the virtual world, are discussed. The virtual world kernel is designed to make extensive use of the parallel processing facilities provided by transputers. It is capable of providing support for mUltiple worlds concurrently, and for multiple users interacting with these worlds. Two applications are described that were successfully implemented using this system. The design of the system is compared with other recently developed virtual reality systems. Features that are common or advantageous in each of the systems are discussed. The system described in this thesis compares favourably, particularly in its use of parallel processors. / KMBT_223
236

Virtual Reality as a Clinical Modality for Retraining Balance and Mobility.

McEwen, Daniel January 2017 (has links)
Physical rehabilitation of individuals who are experiencing a disabling illness or have survived a traumatic injury (i.e. stroke) must seek to train the body’s structures and functions to reduce disability (activity limitations, participation restrictions) (Stucki, 2005). Figure 1 represents a modified version of the International Classification of Functioning (ICF), Disability and Health (World Health Organization, 2002). This figure illustrates how, for example, a stroke impacts the body structures and functions (e.g. muscle recruitment) which influences the ability to complete activities (e.g. gait) ultimately restricting participation in all areas of life (e.g. employment). The ICF model presents a framework for clinical practice and rehabilitation research studies. Although it has been shown to be strongly correlated (Schmid, Van Puymbroeck, et al., 2013) the concept of function cannot always be directly correlated with the concept of quality of life (Stucki, 2005) as the individual may not perceive, for example, impaired balance and mobility as detrimental to their quality of life. However, reduced function does put an individual at further risk of complications including falls and injuries from compensatory mechanisms and therefore must be addressed. The focus of this thesis is the study of the potential benefits of an exercise modality (virtual reality) to encourage restoration of the body’s structures and functions for individuals post-stroke. As the individuals engage in physical rehabilitation through exercise, there may be improvements on the individual’s abilities as seen through measurements of the control of posture and walking. The thesis comprises four studies, two of which have been published in peer reviewed journals. The progression of studies attempts to characterize outcomes following the use of virtual reality training in clinical populations (dementia and stroke) to address impairments to the body structures and functions (e.g. mobility) as measured by both clinical measures of activity and laboratory based measures of balance and to elucidate a possible mechanism (focus of attention) that makes training in a virtual environment effective.
237

Realita a virtualita aneb Je facebook reálný nebo virtuální prostor? / Reality and virtuality. Is Facebook real or virtual space.

Saňková, Klára January 2011 (has links)
Existence of Facebook is based on software. For this reason it is commonly considered and treated as a virtual only space. But this well known phenomenon influences lives of many people and this impact on daily life cannot be overlooked. This thesis is about balancing on that fine line between real and virtual space and about questions that this brings. It gathers together different definitions of those terms and shows what most of Facebook functionality bring to this matter. Based on survey made for this thesis we can say the influence is really being underestimated even tough people that spend lot of their time on Facebook are more aware of its impact.
238

The Invasion: Applying the Aesthetics of Horror in a Virtual Reality Gaming Environment

Unknown Date (has links)
Many theories exist attempting to explain the allure of horror films to the human psyche. None can fully explain this fascination to the horror genre. However, there are clear visual techniques used routinely in these films to produce fear in audiences. This thesis explores the application of those cinematic techniques used in horror cinema for well over a century into a virtual reality (VR) experience, The Invasion. Using a wide range of examples from classic horror films, The Invasion endeavors to show how the lessons learned from the study of horror cinema’s use of color theory, light, shadow, and sound design, when paired with the virtual reality medium, can provide a richer, more immersive horror vehicle and create new possibilities for fear-based content. / Includes bibliography. / Thesis (MFA)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection
239

Kombinierter Einsatz von Augmented Reality in virtuellen Umgebungen

Stelzer, Ralph, Saske, Bernhard, Steindecker, Erik 28 September 2017 (has links)
Virtual Reality (VR) und Augmented Reality (AR) sind innovative Technologien, die in der modernen Entwicklung, Herstellung und Nutzung von Produkten zum Einsatz kommen. Bisher werden beide Technologien nicht gemeinsam genutzt, obwohl eine Kombination in bestimmten Fällen erhebliches Potenzial zur Kosteneinsparung besitzt. Die VR-Technologie wird vorrangig In der Produktentwicklung eingesetzt um Kosten für physische Prototypen einzusparen. Bei der Montage oder der Wartung komplexer Produkte hingegen kommt die AR-Technologie zum Einsatz. Dabei wird der Servicetechniker durch Arbeitsunterlagen, die über ein Display in sein Sichtfeld projiziert werden, bei seiner Tätigkeit unterstützt. Um die Qualität der Arbeitsunterlagen für AR-Systeme schon während der Produktentwicklung zu sichern und einen Schulungsvorlauf beim Servicepersonal zu erreichen, ist die Evaluierung dieser Arbeitsunterlagen bereits am virtuellen Prototyp eines künftigen Produktes sinnvoll. Mit der Kombination von AR und VR Technologie in einem integrierten System sollen für diesen Ansatz die Voraussetzung geschaffen werden. Der Beitrag beschreibt die notwendigen Grundlagen und stellt die Entwicklung eines Systems vor, welches die Wahrnehmung von AR-Informationen am virtuellen Prototyp ermöglicht. Anhand eines gewählten Wartungsszenarios wird das notwendige Vorgehen zum Erstellen von virtuellen Prototyp und AR-Arbeitsunterlagen erläutert und Gestaltungsparameter beschrieben. Basierend auf diesem Szenario wird das entwickelte System in einer Benutzerstudie getestet und Vorschläge für die weitere Entwicklung abgeleitet.
240

Virtual reality utilization in stroke motor neurorehabilitation

Huber, Brandon Michael 21 February 2021 (has links)
The burden of strokes on the healthcare system is tremendous. Strokes are one of the leading causes of long-term morbidity and mortality in the United States. In addition, strokes have a huge economic burden that lasts long after the actual stroke has occurred and has been medically stabilized. Thus, there is a desire to prevent strokes, as well as treat those who have experienced stroke. As technology has and continues to advance, there is the potential for the inclusion of new technologies to become integrated into the healthcare system. One such example is the inclusion of virtual reality in the rehabilitation of patients who have experienced a stroke. The current process of stroke rehabilitation focuses upon returning a patient as close as possible to their baseline level of function. This is generally through the use of repetitive activity to help the brain reroute neuro signaling pathways around damaged areas of the brain. With the inclusion of virtual reality into the process of rehab, it may be possible to better control the environment around a patient and create activities to help better simulate activities of daily life. Through the inclusion of current generation virtual reality into modern rehabilitation regiments it may be possible to better the outcomes of patients who have undergone a stroke with physical deficits. With the current burden of stroke on the medical system it is important to find ways to treat patients as efficiently as possible. By incorporating virtual reality into stroke rehabilitation, there may be better outcomes for patients which will allow them to live better and more capable lives. Much of the research that has been conducted on the matter has shown promise but has lacked large sample sizes and often uses outdated technology. More research must be conducted using more modern technologies and larger sample sizes to show a true benefit in its utilization. The proposed study in this thesis will be a two-armed randomized control trial to assess the efficacy of virtual reality in stroke rehabilitation. The Fugl-Meyer assessment of motor recovery after stroke will be used to evaluate the physical motor benefits of implementation of virtual reality in stroke rehab. The potential benefit of virtual reality into stroke rehab could profoundly impact how we take care of patients who have experienced a stroke. It can create an effective new means to help patients regain their pre-stroke level of function, thus better helping return individuals to their normal lives. This in turn can help decrease costs on the healthcare system by decreasing the number of people living with long term disability.

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