220 research outputs found

    Integrating perceptual, device and location characteristics for wireless multimedia transmission

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    In this paper,we describe an investigation exploring user experiences of accessing streamed multimedia content, when that content is tailored according to perceptual, device and location characteristics. To this end, we have created pre-defined transmission profiles and stream perceptually tailored multimedia content to three different locations, each characterised by different infotainment requirements. In the light of our results, we propose that multimedia transmission to mobile and wireless devices should be made based on pre-defined profiles, which contains a combination of static (perceptual, device type, CPU speed, and display specifications) and dynamic information (streamed content type location of the device/user, context of the device/user). The evaluation of such a system showed that the users and service providers can gain from such an approach considerably, as user perceptions of quality were not detrimentally affected by QoS degradations. Consequently, service providers can utilise this information to effectively manage local network traffic and bandwidth

    Collaborative geographic visualization

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    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente, perfil Gestão 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

    Mobile three-dimensional city maps

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    Maps are visual representations of environments and the objects within, depicting their spatial relations. They are mainly used in navigation, where they act as external information sources, supporting observation and decision making processes. Map design, or the art-science of cartography, has led to simplification of the environment, where the naturally three-dimensional environment has been abstracted to a two-dimensional representation, populated with simple geometrical shapes and symbols. However, abstract representation requires a map reading ability. Modern technology has reached the level where maps can be expressed in digital form, having selectable, scalable, browsable and updatable content. Maps may no longer even be limited to two dimensions, nor to an abstract form. When a real world based virtual environment is created, a 3D map is born. Given a realistic representation, would the user no longer need to interpret the map, and be able to navigate in an inherently intuitive manner? To answer this question, one needs a mobile test platform. But can a 3D map, a resource hungry real virtual environment, exist on such resource limited devices? This dissertation approaches the technical challenges posed by mobile 3D maps in a constructive manner, identifying the problems, developing solutions and providing answers by creating a functional system. The case focuses on urban environments. First, optimization methods for rendering large, static 3D city models are researched and a solution provided by combining visibility culling, level-of-detail management and out-of-core rendering, suited for mobile 3D maps. Then, the potential of mobile networking is addressed, developing efficient and scalable methods for progressive content downloading and dynamic entity management. Finally, a 3D navigation interface is developed for mobile devices, and the research validated with measurements and field experiments. It is found that near realistic mobile 3D city maps can exist in current mobile phones, and the rendering rates are excellent in 3D hardware enabled devices. Such 3D maps can also be transferred and rendered on-the-fly sufficiently fast for navigation use over cellular networks. Real world entities such as pedestrians or public transportation can be tracked and presented in a scalable manner. Mobile 3D maps are useful for navigation, but their usability depends highly on interaction methods - the potentially intuitive representation does not imply, for example, faster navigation than with a professional 2D street map. In addition, the physical interface limits the usability

    A Portable Augmented Reality Science Laboratory

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    Augmented Reality (AR) is a technology which overlays virtual objects on the real world; generates three-dimensional (3D) virtual objects and provides an interactive interface which people can work in the real world and interact with 3D virtual objects at the same time. AR has the potential to engage and motivate learners to explore material from a variety of differing perspective, and has been shown to be particularly useful for teaching subject matter that students could not possibly experience first hand in the real world. This report provides a conceptual framework of a simulated augmented reality lab which could be used in teaching science in classrooms. The recent years, the importance of lab-based courses and its significant role in the science education is irrefutable. The use of AR in formal education could prove a key component in future learning environments that are richly populated with a blend of hardware and software applications. The aim of this project is to enhance the teaching and learning of science by complementing the existing traditional lab with the use of a simulated augmented reality lab. The system architecture and the technical aspects of the proposed project will be described. Implementation issues and benefits of the proposed AR Lab will be highlighted

    Improving the user knowledge and user experience by using Augmented reality in a smart city context

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    Dissertation submitted in partial fulfilment of the requirements for the degree of Master of Science in Geospatial TechnologiesThe idea of Virtuality is not new, as research on visualization and simulation dates back to the early use of ink and paper sketches for alternative design comparisons. As the technology has advanced so the way of visualizing simulations as well, but the progress is slow due to difficulties in creating workable simulations models and effectively providing them to the users (Simpson, 2001). Augmented Reality (AR) and Virtual Reality (VR), the evolving technologies that has been haunting the tech industry, receiving excessive attention from the media and growing tremendously are redefining the way we interact, communicate and work together (Shamalinia, 2017). From consumer application to manufacturers these technologies are used in different sectors providing huge benefits through several applications. In this work, we demonstrate the potentials of AR techniques in a smart city context. Initially we present an overview of the state of the art software and technology for AR in different domains of smart cities, and outline considerations from a user study about the effectiveness and user performance of AR technique: real environment with augmented information, everything in the context of a smart city. The evaluation results from the participants show promising results, providing opportunities for improvements and implementation in smart cities

    A novel visualisation paradigm for three-dimensional map-based mobile services

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    Estágio realizado na NDrive Navigation Systems, S. A.Tese de mestrado integrado. Engenharia Informátca e Computação. Faculdade de Engenharia. Universidade do Porto. 200
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