Adaptive fault-tolerant teleoperation

While the robots gradually become a part of our daily lives, they already play vital roles in many critical operations. Some of these critical tasks include surgeries, battlefield operations, and tasks that take place in hazardous environments or distant locations such as space missions. ^ In most of these tasks, remotely controlled robots are used instead of autonomous robots. This special area of robotics is called teleoperation. Teleoperation systems must be reliable when used in critical tasks; hence, all of the subsystems must be dependable even under a subsystem or communication line failure. ^ These systems are categorized as unilateral or bilateral teleoperation. A special type of bilateral teleoperation is described as force-reflecting teleoperation, which is further investigated as limited- and unlimited-workspace teleoperation. ^ Teleoperation systems configured in this study are tested both in numerical simulations and experiments. A new method, Virtual Rapid Robot Prototyping, is introduced to create system models rapidly and accurately. This method is then extended to configure experimental setups with actual master systems working with system models of the slave robots accompanied with virtual reality screens as well as the actual slaves. Fault-tolerant design and modeling of the master and slave systems are also addressed at different levels to prevent subsystem failure. ^ Teleoperation controllers are designed to compensate for instabilities due to communication time delays. Modifications to the existing controllers are proposed to configure a controller that is reliable in communication line failures. Position/force controllers are also introduced for master and/or slave robots. Later, controller architecture changes are discussed in order to make these controllers dependable even in systems experiencing communication problems. ^ The customary and proposed controllers for teleoperation systems are tested in numerical simulations on single- and multi-DOF teleoperation systems. Experimental studies are then conducted on seven different systems that included limited- and unlimited-workspace teleoperation to verify and improve simulation studies. ^ Experiments of the proposed controllers were successful relative to the customary controllers. Overall, by employing the fault-tolerance features and the proposed controllers, a more reliable teleoperation system is possible to design and configure which allows these systems to be used in a wider range of critical missions. ^

Advances in Hospitality Education: Courseware, Audiographics, and Cyberspace

Technology will play an increasingly larger role in the education of students within the hospitality curriculum. There are a significant number of emerging educational technologies aimed at changing the delivery of the entire curriculum. The development of technological platforms for multimedia instructional courseware, distance learning through audiographics, and virtual reality simulation are expected to alter and enhance the learning process while extending the boundaries of the traditional hospitality classroom.

Multimedia Training: Why Some use it and Some Do Not

Forms of interactive multimedia, including CD-ROM, DV-I, Laserdisc, and virtual reality, have given a new perspective to training in many industries. As the hospitality industry and other service industries continue to grow, these forms of technology are becoming of increasing interest as organizations strive to deliver more efficient and effective services to customers and employees

Adaptive Fault-Tolerant Teleoperation

While the robots gradually become a part of our daily lives, they already play vital roles in many critical operations. Some of these critical tasks include surgeries, battlefield operations, and tasks that take place in hazardous environments or distant locations such as space missions. In most of these tasks, remotely controlled robots are used instead of autonomous robots. This special area of robotics is called teleoperation. Teleoperation systems must be reliable when used in critical tasks; hence, all of the subsystems must be dependable even under a subsystem or communication line failure. These systems are categorized as unilateral or bilateral teleoperation. A special type of bilateral teleoperation is described as force-reflecting teleoperation, which is further investigated as limited- and unlimited-workspace teleoperation. Teleoperation systems configured in this study are tested both in numerical simulations and experiments. A new method, Virtual Rapid Robot Prototyping, is introduced to create system models rapidly and accurately. This method is then extended to configure experimental setups with actual master systems working with system models of the slave robots accompanied with virtual reality screens as well as the actual slaves. Fault-tolerant design and modeling of the master and slave systems are also addressed at different levels to prevent subsystem failure. Teleoperation controllers are designed to compensate for instabilities due to communication time delays. Modifications to the existing controllers are proposed to configure a controller that is reliable in communication line failures. Position/force controllers are also introduced for master and/or slave robots. Later, controller architecture changes are discussed in order to make these controllers dependable even in systems experiencing communication problems. The customary and proposed controllers for teleoperation systems are tested in numerical simulations on single- and multi-DOF teleoperation systems. Experimental studies are then conducted on seven different systems that included limited- and unlimited-workspace teleoperation to verify and improve simulation studies. Experiments of the proposed controllers were successful relative to the customary controllers. Overall, by employing the fault-tolerance features and the proposed controllers, a more reliable teleoperation system is possible to design and configure which allows these systems to be used in a wider range of critical missions.

Realtà virtuale multiutente

L’obbiettivo di questa tesi è realizzare il prototipo di un’applicazione client-server che permetta di utilizzare in remoto applicazioni in Virtual Reality, fornendo allo stesso tempo supporto alla multiutenza. L’applicazione in realtà virtuale dovrà girare sul server, dispositivo con capacità di calcolo notevolmente superiori rispetto a quelle del client. Più utenti dovranno avere la possibilità di connettersi contemporaneamente e condividere lo stesso spazio virtuale. Il client sarà, in questo caso, un’applicazione Android che si connetterà al server e avrà il compito di mostrare all'utente l’output dell’applicazione in Virtual Reality e allo stesso tempo ricevere l’input da inviare al server. Un altro obbiettivo durante lo sviluppo del prototipo è quello di realizzare una libreria che offra le funzionalità sopraelencate, facilmente integrabile in nuovi progetti o in progetti già esistenti. Utilizzando questa struttura client-server sarà possibile sviluppare applicazioni che permettano a più persone di condividere lo stesso spazio virtuale, ognuno dal proprio punto di vista, utilizzando visori e sistemi operativi diversi.

Uma estratégia para otimizar a geração de arranjos em subestações virtuais de energia elétrica

The Virtual Reality techniques applied in Electricity Environments provide a new supervisory control paradigm. The fact of existing a virtual environment (VE), geometrically similar to a real substation, reduces the difference of mental models built by field operators compared with those built by system center operation improving the communication. Beside this, those systems can be used as visualization interfaces for electricity system simulators, training systems for professors and undergraduate students, field operators and maintenance professionals. However, the development process of these systems is quite complex, combining several activities such as implementation, 3D modeling, virtual sceneries construction, usability assessment and management project techniques. In this context, this work present a GUI strategy to build field arrangements based on scene graphs, to reduce time in Virtual Electricity Substations Arrangement development. Through this, mistakes during the VE building can be avoided making this process more reliable. As an concept proof, all toolkits developed in this work were applied in the virtualization of the substations from a Brazilian power concessionary named CEMIG.

Uma metodologia para geração otimizada de ambientes virtuais baseados em usinas hidrelétricas

Based on the possibility of real-time interaction with three-dimensional environments through an advanced interface, Virtual Reality consist in the main technology of this work, used in the design of virtual environments based on real Hydroelectric Plants. Previous to the process of deploying a Virtual Reality System for operation, three-dimensional modeling and interactive scenes settings are very importante steps. However, due to its magnitude and complexity, power plants virtual environments generation, currently, presents high computing cost. This work aims to present a methodology to optimize the production process of virtual environments associated with real hydroelectric power plants. In partnership with electric utility CEMIG, several HPPs were used in the scope of this work. During the modeling of each one of them, the techiniques within the methodologie were addressed. After the evaluation of the computional techniques presented here, it was possible to confirm a reduction in the time required to deliver each hydroelectrical complex. Thus, this work presents the current scenario about development of virtual hydroelectric power plants and discusses the proposed methodology that seeks to optimize this process in the electricity generation sector.

Expertise sportive et entraînement perceptivo-cognitif de l’athlète

Pour être performant au plus haut niveau, les athlètes doivent posséder une capacité perceptivo-cognitive supérieure à la moyenne. Cette faculté, reflétée sur le terrain par la vision et l’intelligence de jeu des sportifs, permet d’extraire l’information clé de la scène visuelle. La science du sport a depuis longtemps observé l’expertise perceptivo-cognitive au sein de l’environnement sportif propre aux athlètes. Récemment, des études ont rapporté que l’expertise pouvait également se refléter hors de ce contexte, lors d’activités du quotidien par exemple. De plus, les récentes théories entourant la capacité plastique du cerveau ont amené les chercheurs à développer des outils pour entraîner les capacités perceptivo-cognitives des athlètes afin de les rendre plus performants sur le terrain. Ces méthodes sont la plupart du temps contextuelles à la discipline visée. Cependant, un nouvel outil d’entraînement perceptivo-cognitif, nommé 3-Dimensional Multiple Object Tracking (3D-MOT) et dénué de contexte sportif, a récemment vu le jour et a fait l’objet de nos recherches. Un de nos objectifs visait à mettre en évidence l’expertise perceptivo-cognitive spécifique et non-spécifique chez des athlètes lors d’une même étude. Nous avons évalué la perception du mouvement biologique chez des joueurs de soccer et des non-athlètes dans une salle de réalité virtuelle. Les sportifs étaient systématiquement plus performants en termes d’efficacité et de temps de réaction que les novices pour discriminer la direction du mouvement biologique lors d’un exercice spécifique de soccer (tir) mais également lors d’une action issue du quotidien (marche). Ces résultats signifient que les athlètes possèdent une meilleure capacité à percevoir les mouvements biologiques humains effectués par les autres. La pratique du soccer semble donc conférer un avantage fondamental qui va au-delà des fonctions spécifiques à la pratique d’un sport. Ces découvertes sont à mettre en parallèle avec la performance exceptionnelle des athlètes dans le traitement de scènes visuelles dynamiques et également dénuées de contexte sportif. Des joueurs de soccer ont surpassé des novices dans le test de 3D-MOT qui consiste à suivre des cibles en mouvement et stimule les capacités perceptivo-cognitives. Leur vitesse de suivi visuel ainsi que leur faculté d’apprentissage étaient supérieures. Ces résultats confirmaient des données obtenues précédemment chez des sportifs. Le 3D-MOT est un test de poursuite attentionnelle qui stimule le traitement actif de l’information visuelle dynamique. En particulier, l’attention sélective, dynamique et soutenue ainsi que la mémoire de travail. Cet outil peut être utilisé pour entraîner les fonctions perceptivo-cognitives des athlètes. Des joueurs de soccer entraînés au 3D-MOT durant 30 sessions ont montré une amélioration de la prise de décision dans les passes de 15% sur le terrain comparés à des joueurs de groupes contrôles. Ces données démontrent pour la première fois un transfert perceptivo-cognitif du laboratoire au terrain suivant un entraînement perceptivo-cognitif non-contextuel au sport de l’athlète ciblé. Nos recherches aident à comprendre l’expertise des athlètes par l’approche spécifique et non-spécifique et présentent également les outils d’entraînements perceptivo-cognitifs, en particulier le 3D-MOT, pour améliorer la performance dans le sport de haut-niveau.

Death Threat Letters: Allegories of American Authorship in the Age of Terrorism

This dissertation examines novels that use terrorism to allegorize the threatened position of the literary author in contemporary culture. Allegory is a term that has been differently understood over time, but which has consistently been used by writers to articulate and construct their roles as authors. In the novels I look at, the terrorist challenge to authorship results in multiple deployments of allegory, each differently illustrating the way that allegory is used and authorship constructed in the contemporary American novel. Don DeLillo’s Mao II (1991), first puts terrorists and authors in an oppositional pairing. The terrorist’s ability to traffic in spectacle is presented as indicative of the author’s fading importance in contemporary culture and it is one way that terrorism allegorizes threats to authorship. In Philip Roth’s Operation Shylock (1993), the allegorical pairing is between the text of the novel and outside texts – newspaper reports, legal cases, etc. – that the novel references and adapts in order to bolster its own narrative authority. Richard Powers’s Plowing the Dark (1999) pairs the story of an imprisoned hostage, craving a single book, with employees of a tech firm who are creating interactive, virtual reality artworks. Focusing on the reader’s experience, Powers’s novel posits a form of authorship that the reader can take into consideration, but which does not seek to control the experience of the text. Finally, I look at two of Paul Auster’s twenty-first century novels, Travels in the Scriptorium (2007) and Man in the Dark (2008), to suggest that the relationship between representations of authors and terrorists changed after 9/11. Auster’s author-figures forward an ethics of authorship whereby novels can use narrative to buffer readers against the portrayal of violent acts in a culture that is suffused with traumatizing imagery.

Circular migration and the Internet: The role of social networks in the sociocultural context of Mexican residents in Barcelona

This work focuses on the study of the circular migration between America and Europe, particularly in the discussion about knowledge transfer and the way that social networks reconfigure the form of information distribution among people, that due to labor and academic issues have left their own country. The main purpose of this work is to study the impact of social media use in migration flows between Mexico and Spain, more specifically the use by Mexican migrants who have moved for  multiple years principally for educational purposes and then have returned to their respective locations in Mexico seeking to integrate themselves into the labor market. Our data collection concentrated exclusively on a group created on Facebook by Mexicans who mostly reside in Barcelona, Spain or wish to travel to the city for economic, educational or tourist reasons.  The results of this research show that while social networks are spaces for exchange and integration, there is a clear tendency by this group to "narrow lines" and to look back to their homeland, slowing the process of opening socially in their new context.

Simulations in 3D research : Can Unity3D be used to simulate a 3D display system?

Mid Sweden University is currently researching how to capture more of a scene with a camera and how to create 3D images that does not require extra equipment for the viewer. In the process of this research they have started looking into simulating some of the tests that they wish to conduct. The goal of this project is to research whether the 3D graphics engine Unity3D could be used to simulate these tests, and to what degree. To test this a simulation was designed and implemented. The simulation used a split display system where each camera is directly connected to a part of the screen and using the position of the viewer the correct part of the camera feed is shown. Some literary studies were also done into how current 3D technology works. The simulation was successfully implemented and shows that simple simulation can be done in Unity3D, however, some problems were encountered in the process. The conclusion of the project show that there is much work left before simulation is viable but that there is potential in the technology and that the research team should continue to investigate it.

Real-time depth camera tracking with CAD models and ICP

In recent years, depth cameras have been widely utilized in camera tracking for augmented and mixed reality. Many of the studies focus on the methods that generate the reference model simultaneously with the tracking and allow operation in unprepared environments. However, methods that rely on predefined CAD models have their advantages. In such methods, the measurement errors are not accumulated to the model, they are tolerant to inaccurate initialization, and the tracking is always performed directly in reference model's coordinate system. In this paper, we present a method for tracking a depth camera with existing CAD models and the Iterative Closest Point (ICP) algorithm. In our approach, we render the CAD model using the latest pose estimate and construct a point cloud from the corresponding depth map. We construct another point cloud from currently captured depth frame, and find the incremental change in the camera pose by aligning the point clouds. We utilize a GPGPU-based implementation of the ICP which efficiently uses all the depth data in the process. The method runs in real-time, it is robust for outliers, and it does not require any preprocessing of the CAD models. We evaluated the approach using the Kinect depth sensor, and compared the results to a 2D edge-based method, to a depth-based SLAM method, and to the ground truth. The results show that the approach is more stable compared to the edge-based method and it suffers less from drift compared to the depth-based SLAM.

The music video in the new media: music as an integrated experience

"The Music Vidio in the New Media" is an exploration of the past, present and future of the music cullture. After the evaluation of the existing new media chanels I propose Virtual Reality as a potential media to experience the music. The project explores following terms and topics within them: New Media / New Media Channels and Virtual Reality (...)

Realidade aumentada aplicada em bibliotecas: multiplicidade no acesso a informação

Conceitua Realidade Aumentada do ponto de vista histórico de vários autores e como surgiu esse segmento através da evolução tecnológica até os dias atuais. Aborda seu funcionamento, como também, seus sistemas e aplicações em diversos campos de pesquisas e estudos científicos. Diferencia Realidade Aumentada de Realidade Virtual, visando melhor esclarecimento entre ambas na intenção de descaracterizá-las com uma única “realidade”. Apresenta a Realidade Aumentada e sua aplicação dentro de um contexto de uma unidade de informação, promovendo uma melhor interação com os usuários e as adaptações pelas quais as bibliotecas terão que passar futuramente para se adequarem a “explosão” tecnológica. Descreve o funcionamento da biblioteca ARToolKIT, baseada em RA e suas principais etapas de funcionamento para visualização de objetos virtuais em 3D. Exemplifica os benefícios que uma unidade de informação, que utiliza Realidade Aumentada, promove aos usuários portadores de deficiência, além de sua inclusão no meio digital e sua inserção no mercado de trabalho

Principles and Practice of Fire Modelling: A Collection of Lecture Notes for a Short Course

Once the preserve of university academics and research laboratories with high-powered and expensive computers, the power of sophisticated mathematical fire models has now arrived on the desk top of the fire safety engineer. It is a revolution made possible by parallel advances in PC technology and fire modelling software. But while the tools have proliferated, there has not been a corresponding transfer of knowledge and understanding of the discipline from expert to general user. It is a serious shortfall of which the lack of suitable engineering courses dealing with the subject is symptomatic, if not the cause. The computational vehicles to run the models and an understanding of fire dynamics are not enough to exploit these sophisticated tools. Too often, they become 'black boxes' producing magic answers in exciting three-dimensional colour graphics and client-satisfying 'virtual reality' imagery. As well as a fundamental understanding of the physics and chemistry of fire, the fire safety engineer must have at least a rudimentary understanding of the theoretical basis supporting fire models to appreciate their limitations and capabilities. The five day short course, "Principles and Practice of Fire Modelling" run by the University of Greenwich attempt to bridge the divide between the expert and the general user, providing them with the expertise they need to understand the results of mathematical fire modelling. The course and associated text book, "Mathematical Modelling of Fire Phenomena" are aimed at students and professionals with a wide and varied background, they offer a friendly guide through the unfamiliar terrain of mathematical modelling. These concepts and techniques are introduced and demonstrated in seminars. Those attending also gain experience in using the methods during "hands-on" tutorial and workshop sessions. On completion of this short course, those participating should: - be familiar with the concept of zone and field modelling; - be familiar with zone and field model assumptions; - have an understanding of the capabilities and limitations of modelling software packages for zone and field modelling; - be able to select and use the most appropriate mathematical software and demonstrate their use in compartment fire applications; and - be able to interpret model predictions. The result is that the fire safety engineer is empowered to realise the full value of mathematical models to help in the prediction of fire development, and to determine the consequences of fire under a variety of conditions. This in turn enables him or her to design and implement safety measures which can potentially control, or at the very least reduce the impact of fire.