311 research outputs found

    Collaborative geographic visualization

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    Dissertação apresentada na Faculdade de CiĂȘncias e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente, perfil GestĂŁo e Sistemas AmbientaisThe present document is a revision of essential references to take into account when developing ubiquitous Geographical Information Systems (GIS) with collaborative visualization purposes. Its chapters focus, respectively, on general principles of GIS, its multimedia components and ubiquitous practices; geo-referenced information visualization and its graphical components of virtual and augmented reality; collaborative environments, its technological requirements, architectural specificities, and models for collective information management; and some final considerations about the future and challenges of collaborative visualization of GIS in ubiquitous environment

    SInCom 2015

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    2nd Baden-WĂŒrttemberg Center of Applied Research Symposium on Information and Communication Systems, SInCom 2015, 13. November 2015 in Konstan

    Air Force Institute of Technology Research Report 2009

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    This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physics

    Eye tracking and avatar-mediated communication in immersive collaborative virtual environments

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    The research presented in this thesis concerns the use of eye tracking to both enhance and understand avatar-mediated communication (AMC) performed by users of immersive collaborative virtual environment (ICVE) systems. AMC, in which users are embodied by graphical humanoids within a shared virtual environment (VE), is rapidly emerging as a prevalent and popular form of remote interaction. However, compared with video-mediated communication (VMC), which transmits interactants’ actual appearance and behaviour, AMC fails to capture, transmit, and display many channels of nonverbal communication (NVC). This is a significant hindrance to the medium’s ability to support rich interpersonal telecommunication. In particular, oculesics (the communicative properties of the eyes), including gaze, blinking, and pupil dilation, are central nonverbal cues during unmediated social interaction. This research explores the interactive and analytical application of eye tracking to drive the oculesic animation of avatars during real-time communication, and as the primary method of experimental data collection and analysis, respectively. Three distinct but interrelated questions are addressed. First, the thesis considers the degree to which quality of communication may be improved through the use of eye tracking, to increase the nonverbal, oculesic, information transmitted during AMC. Second, the research asks whether users engaged in AMC behave and respond in a socially realistic manner in comparison with VMC. Finally, the degree to which behavioural simulations of oculesics can both enhance the realism of virtual humanoids, and complement tracked behaviour in AMC, is considered. These research questions were investigated over a series of telecommunication experiments investigating scenarios common to computer supported cooperative work (CSCW), and a further series of experiments investigating behavioural modelling for virtual humanoids. The first, exploratory, telecommunication experiment compared AMC with VMC in a three-party conversational scenario. Results indicated that users employ gaze similarly when faced with avatar and video representations of fellow interactants, and demonstrated how interaction is influenced by the technical characteristics and limitations of a medium. The second telecommunication experiment investigated the impact of varying methods of avatar gaze control on quality of communication during object-focused multiparty AMC. The main finding of the experiment was that quality of communication is reduced when avatars demonstrate misleading gaze behaviour. The final telecommunication study investigated truthful and deceptive dyadic interaction in AMC and VMC over two closely-related experiments. Results from the first experiment indicated that users demonstrate similar oculesic behaviour and response in both AMC and VMC, but that psychological arousal is greater following video-based interaction. Results from the second experiment found that the use of eye tracking to drive the oculesic behaviour of avatars during AMC increased the richness of NVC to the extent that more accurate estimation of embodied users’ states of veracity was enabled. Rather than directly investigating AMC, the second series of experiments addressed behavioural modelling of oculesics for virtual humanoids. Results from the these experiments indicated that oculesic characteristics are highly influential to the perceived realism of virtual humanoids, and that behavioural models are able to complement the use of eye tracking in AMC. The research presented in this thesis explores AMC and eye tracking over a range of collaborative and perceptual studies. The overall conclusion is that eye tracking is able to enhance AMC towards a richer medium for interpersonal telecommunication, and that users’ behaviour in AMC is no less socially ‘real’ than that demonstrated in VMC. However, there are distinct differences between the two communication mediums, and the importance of matching the characteristics of a planned communication with those of the medium itself is critical

    An inertial motion capture framework for constructing body sensor networks

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    Motion capture is the process of measuring and subsequently reconstructing the movement of an animated object or being in virtual space. Virtual reconstructions of human motion play an important role in numerous application areas such as animation, medical science, ergonomics, etc. While optical motion capture systems are the industry standard, inertial body sensor networks are becoming viable alternatives due to portability, practicality and cost. This thesis presents an innovative inertial motion capture framework for constructing body sensor networks through software environments, smartphones and web technologies. The first component of the framework is a unique inertial motion capture software environment aimed at providing an improved experimentation environment, accompanied by programming scaffolding and a driver development kit, for users interested in studying or engineering body sensor networks. The software environment provides a bespoke 3D engine for kinematic motion visualisations and a set of tools for hardware integration. The software environment is used to develop the hardware behind a prototype motion capture suit focused on low-power consumption and hardware-centricity. Additional inertial measurement units, which are available commercially, are also integrated to demonstrate the functionality the software environment while providing the framework with additional sources for motion data. The smartphone is the most ubiquitous computing technology and its worldwide uptake has prompted many advances in wearable inertial sensing technologies. Smartphones contain gyroscopes, accelerometers and magnetometers, a combination of sensors that is commonly found in inertial measurement units. This thesis presents a mobile application that investigates whether the smartphone is capable of inertial motion capture by constructing a novel omnidirectional body sensor network. This thesis proposes a novel use for web technologies through the development of the Motion Cloud, a repository and gateway for inertial data. Web technologies have the potential to replace motion capture file formats with online repositories and to set a new standard for how motion data is stored. From a single inertial measurement unit to a more complex body sensor network, the proposed architecture is extendable and facilitates the integration of any inertial hardware configuration. The Motion Cloud’s data can be accessed through an application-programming interface or through a web portal that provides users with the functionality for visualising and exporting the motion data

    Wearables at work:preferences from an employee’s perspective

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    This exploratory study aims to obtain a first impression of the wishes and needs of employees on the use of wearables at work for health promotion. 76 employ-ees with a mean age of 40 years old (SD ±11.7) filled in a survey after trying out a wearable. Most employees see the potential of using wearable devices for workplace health promotion. However, according to employees, some negative aspects should be overcome before wearables can effectively contribute to health promotion. The most mentioned negative aspects were poor visualization and un-pleasantness of wearing. Specifically for the workplace, employees were con-cerned about the privacy of data collection

    QoS in Body Area Networks: A survey

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    Contention techniques for opportunistic communication in wireless mesh networks

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    Auf dem Gebiet der drahtlosen Kommunikation und insbesondere auf den tieferen Netzwerkschichten sind gewaltige Fortschritte zu verzeichnen. Innovative Konzepte und Technologien auf der physikalischen Schicht (PHY) gehen dabei zeitnah in zellulĂ€re Netze ein. Drahtlose Maschennetzwerke (WMNs) können mit diesem Innovationstempo nicht mithalten. Die Mehrnutzer-Kommunikation ist ein Grundpfeiler vieler angewandter PHY Technologien, die sich in WMNs nur ungenĂŒgend auf die etablierte Schichtenarchitektur abbilden lĂ€sst. Insbesondere ist das Problem des Scheduling in WMNs inhĂ€rent komplex. Erstaunlicherweise ist der Mehrfachzugriff mit TrĂ€gerprĂŒfung (CSMA) in WMNs asymptotisch optimal obwohl das Verfahren eine geringe DurchfĂŒhrungskomplexitĂ€t aufweist. Daher stellt sich die Frage, in welcher Weise das dem CSMA zugrunde liegende Konzept des konkurrierenden Wettbewerbs (engl. Contention) fĂŒr die Integration innovativer PHY Technologien verwendet werden kann. Opportunistische Kommunikation ist eine Technik, die die inhĂ€renten Besonderheiten des drahtlosen Kanals ausnutzt. In der vorliegenden Dissertation werden CSMA-basierte Protokolle fĂŒr die opportunistische Kommunikation in WMNs entwickelt und evaluiert. Es werden dabei opportunistisches Routing (OR) im zustandslosen Kanal und opportunistisches Scheduling (OS) im zustandsbehafteten Kanal betrachtet. Ziel ist es, den Durchsatz von elastischen PaketflĂŒssen gerecht zu maximieren. Es werden Modelle fĂŒr Überlastkontrolle, Routing und konkurrenzbasierte opportunistische Kommunikation vorgestellt. Am Beispiel von IEEE 802.11 wird illustriert, wie der schichtĂŒbergreifende Entwurf in einem Netzwerksimulator prototypisch implementiert werden kann. Auf Grundlage der Evaluationsresultate kann der Schluss gezogen werden, dass die opportunistische Kommunikation konkurrenzbasiert realisierbar ist. DarĂŒber hinaus steigern die vorgestellten Protokolle den Durchsatz im Vergleich zu etablierten Lösungen wie etwa DCF, DSR, ExOR, RBAR und ETT.In the field of wireless communication, a tremendous progress can be observed especially at the lower layers. Innovative physical layer (PHY) concepts and technologies can be rapidly assimilated in cellular networks. Wireless mesh networks (WMNs), on the other hand, cannot keep up with the speed of innovation at the PHY due to their flat and decentralized architecture. Many innovative PHY technologies rely on multi-user communication, so that the established abstraction of the network stack does not work well for WMNs. The scheduling problem in WMNs is inherent complex. Surprisingly, carrier sense multiple access (CSMA) in WMNs is asymptotically utility-optimal even though it has a low computational complexity and does not involve message exchange. Hence, the question arises whether CSMA and the underlying concept of contention allows for the assimilation of advanced PHY technologies into WMNs. In this thesis, we design and evaluate contention protocols based on CSMA for opportunistic communication in WMNs. Opportunistic communication is a technique that relies on multi-user diversity in order to exploit the inherent characteristics of the wireless channel. In particular, we consider opportunistic routing (OR) and opportunistic scheduling (OS) in memoryless and slow fading channels, respectively. We present models for congestion control, routing and contention-based opportunistic communication in WMNs in order to maximize both throughput and fairness of elastic unicast traffic flows. At the instance of IEEE 802.11, we illustrate how the cross-layer algorithms can be implemented within a network simulator prototype. Our evaluation results lead to the conclusion that contention-based opportunistic communication is feasible. Furthermore, the proposed protocols increase both throughput and fairness in comparison to state-of-the-art approaches like DCF, DSR, ExOR, RBAR and ETT

    Air Force Institute of Technology Research Report 2013

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    This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems Engineering and Management, Operational Sciences, Mathematics, Statistics and Engineering Physics

    Robot Games for Elderly:A Case-Based Approach

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