837 resultados para 3D multi-user virtual environments
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The potential of integrating multiagent systems and virtual environments has not been exploited to its whole extent. This paper proposes a model based on grammars, called Minerva, to construct complex virtual environments that integrate the features of agents. A virtual world is described as a set of dynamic and static elements. The static part is represented by a sequence of primitives and transformations and the dynamic elements by a series of agents. Agent activation and communication is achieved using events, created by the so-called event generators. The grammar defines a descriptive language with a simple syntax and a semantics, defined by functions. The semantics functions allow the scene to be displayed in a graphics device, and the description of the activities of the agents, including artificial intelligence algorithms and reactions to physical phenomena. To illustrate the use of Minerva, a practical example is presented: a simple robot simulator that considers the basic features of a typical robot. The result is a functional simple simulator. Minerva is a reusable, integral, and generic system, which can be easily scaled, adapted, and improved. The description of the virtual scene is independent from its representation and the elements that it interacts with.
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Building Information Modelling (BIM) provides a shared source of information about a built asset, which creates a collaborative virtual environment for project teams. Literature suggests that to collaborate efficiently, the relationship between the project team is based on sympathy, obligation, trust and rapport. Communication increases in importance when working collaboratively but effective communication can only be achieved when the stakeholders are willing to act, react, listen and share information. Case study research and interviews with Architecture, Engineering and Construction (AEC) industry experts suggest that synchronous face-to-face communication is project teams’ preferred method, allowing teams to socialise and build rapport, accelerating the creation of trust between the stakeholders. However, virtual unified communication platforms are a close second-preferred option for communication between the teams. Effective methods for virtual communication in professional practice, such as virtual collaboration environments (CVE), that build trust and achieve similar spontaneous responses as face-to-face communication, are necessary to face the global challenges and can be achieved with the right people, processes and technology. This research paper investigates current industry methods for virtual communication within BIM projects and explores the suitability of avatar interaction in a collaborative virtual environment as an alternative to face-to-face communication to enhance collaboration between design teams’ professional practice on a project. Hence, this paper presents comparisons between the effectiveness of these communication methods within construction design teams with results of further experiments conducted to test recommendations for more efficient methods for virtual communication to add value in the workplace between design teams.
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Virtual reality exposure therapy (VRET) developed using immersive or semi-immersive virtual environments present a usability problem for practitioners. To meet practitioner requirements for lower cost and portability VRET programs must often be ported onto desktop environments such as the personal computer (PC). However, success of VRET has been shown to be linked to presence, and the environment's ability to evoke the same reactions and emotions as a real experience. It is generally accepted that high-end virtual environments ( VEs) are more immersive than desktop PCs, but level of immersion does not always predict level of presence. This paper reports on the impact on presence of porting a therapeutic VR application for Schizophrenia from the initial research environment of a semi-immersive curved screen to PC. Presence in these two environments is measured both introspectively and across a number of causal factors thought to underlie the experience of presence. Results show that the VR exposure program successfully made users feel they were present in both platforms. While the desktop PC achieved higher scores on presence across causal factors participants reported they felt more present in the curved screen environment. While comparison of the two groups was statistically significant for the PQ but not for the IPQ, subjective reports of experiences in the environments should be considered in future research as the success of VRET relies heavily on the emotional response of patients to the therapeutic program.
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O trabalho intitulado Narrativas de usos pedagógicos de ferramentas tecnológicas na docência do Ensino Médio tem como objetivo conhecer e mapear as experiências de professores do Ensino Médio que integram em sua prática pedagógica recursos tecnológicos através de suas narrativas, os quais atuam em escolas públicas da região de São Paulo. Sendo assim, a prática pedagógica com o uso de tecnologia se faz presente na docência do professor de ensino médio, transformando-o em agente mediador do processo ensino-aprendizagem. A metodologia da pesquisa se concentra na experiência dos professores que utilizam a tecnologia como ferramenta de sua prática mediante a investigação narrativa, a qual os autores Connely e Claudinin elucidam em sua obra. São ressaltados alguns autores durante a pesquisa exploratória e documental, como: Moran, Lévy, Perrenoud e Tardif, conceituando a atuação do professor em Freire e Zabala, mediando sua prática com a tecnologia, levando a resultados que propiciam um ensino adequado à aprendizagem. Os instrumentos investigativos da pesquisa adotados na pesquisa foram: entrevista semi-estruturada, conversas informais com os professores, registro dos participantes nos fóruns do Portal educacional e reuniões pedagógicas coma a coordenadora do Portal educacional. O processo organizativo da análise das narrativas dos docentes se realizou por categorias tais como: organização do conteúdo pelos professores, uso do Portal educacional e interdisciplinaridade. Nas narrativas dos participantes da pesquisa percebeu-se que o trabalho na comunidade virtual baseou-se em três pontos fundamentais: produção, troca de informações e apresentação de resultados. De acordo com os relatos apresentados pelos entrevistados conclui-se que o trabalho desenvolvido pelos professores é bastante rico e contribui para a troca de experiências entre docentes pesquisadores da rede, que diferenciam suas aulas através do uso de tecnologia por meio do Portal educacional. Destaca-se também como diferencial na pesquisa a escolha, pelos docentes, de algumas ferramentas com o uso do Portal.
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As more consumers shop online, it becomes crucial for marketers to know how online shopping environments (OSEs) can be used to gain competitive advantage. This dissertation aims to explain theoretically how OSE attributes work together holistically to produce desirable consumer responses, applying and extending a theory from the environmental psychology literature to the online context. Firstly, the study conceptualises OSEs as virtual environments which may be perceived and experienced both cognitively and affectively through a technology-mediated interaction with a computer screen. A multi-disciplinary approach identifies key characteristics of OSEs: they involve consumers; they are more complex than their offline counterparts; they are likely first apprehended holistically; and they can elicit high levels of emotions and cognition. Secondly, the research uses a gestalt approach and extends Kaplan and Kalan’s (1982) Preference Framework, taking account of the specific characteristics of OSEs, which one visits specifically to obtain product information. The results support the proposition that OSEs are perceived in terms of their Sense-making and Exploratory attributes. Thirdly, the research explains how OSE attributes work together to produce desirable consumer responses. As hypothesised, Exploratory potential produces both Hedonic and Utilitarian value, and both kinds of value contribute to Site commitment. An unexpected result is that Sense-making potential does not produce Utilitarian value directly, but only through the mediation of Exploratory potential. The research contributes to marketing theory by: (1) identifying ways the internet has changed the nature of the shopping experience; (2) extending Kaplan and Kaplan’s Preference Framework to explain how consumers perceive OSEs holistically; (3) identifying the distinction between page-level and site-level perceptions, and (4) distinguishing between different sources of information (marketer vs. non-marketer). Managerially, the research provides a model for marketers to conceive and design retail websites whose attributes work together to create competitive advantage.
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Agents inhabiting large scale environments are faced with the problem of generating maps by which they can navigate. One solution to this problem is to use probabilistic roadmaps which rely on selecting and connecting a set of points that describe the interconnectivity of free space. However, the time required to generate these maps can be prohibitive, and agents do not typically know the environment in advance. In this paper we show that the optimal combination of different point selection methods used to create the map is dependent on the environment, no point selection method dominates. This motivates a novel self-adaptive approach for an agent to combine several point selection methods. The success rate of our approach is comparable to the state of the art and the generation cost is substantially reduced. Self-adaptation therefore enables a more efficient use of the agent's resources. Results are presented for both a set of archetypal scenarios and large scale virtual environments based in Second Life, representing real locations in London.
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The correct distance perception is important for executing various interactive tasks such as navigation, selection and manipulation. It is known, however, that, in general, there is a significant distance perception compression in virtual environments, mainly when using Head-Mounted Displays - HMDs. This perceived distance compression may bring various problems to the applications and even affect in a negative way the utility of those applications that depends on the correct judgment of distances. The scientific community, so far, have not been able to determine the causes of the distance perception compression in virtual environments. For this reason, it was the objective of this work to investigate, through experiments with users, the influence of both the field-of-view - FoV - and the distance estimation methods on this perceived compression. For that, an experimental comparison between the my3D device and a HMD, using 32 participants, seeking to find information on the causes of the compressed perception, was executed. The results showed that the my3D has inferior capabilities when compared to the HMD, resulting in worst estimations, on average, in both the tested estimation methods. The causes of that are believed to be the incorrect stimulus of the peripheral vision of the user, the smaller FoV and the smaller immersion sense, as described by the participants of the experiment.
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Navigation, in both virtual and real environments, is the process of a deliberated movement to a specific place that is usually away from the origin point, and that cannot be perceived from it. Navigation aid techniques (TANs) have as their main objective help finding a path through a virtual environment to a desired location and, are widely used because they ease the navigation on these unknown environments. Tools like maps, GPS (Global Positioning System) or even oral instructions are real world examples of TAN usage. Most of the works which propose new TANs for virtual environments aim to analyze their impact in efficiency gain on navigation tasks from a known place to an unknown place. However, such papers tend to ignore the effect caused by a TAN usage over the route knowledge acquisition process, which is important on virtual to real training transfer, for example. Based on a user study, it was possible to confirm that TANs with different strategies affects the performance of search tasks differently and that the efficiency of the help provided by a TAN is not inversely related to the cognitive load of the technique’s aids. A technique classification formula was created. This formula utilizes three factors instead of only efficiency. The experiment’s data were applied to the formula and we obtained a better refinement of help level provided by TANs.
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This study describes the development of a prototype to evaluate the potential of environments based on two-dimensional modeling and virtual reality as power substations learning objects into training environments from a central operation and control of power utility Cemig. Initially, there was an identification modeling features and cognitive processes in 2D and RV, from which it was possible to create frames that serve to guide the preparation of a checklist with assigning a metric weight for measuring cognitive potential learning in the study sites. From these contents twenty-four questions were prepared and each was assigned a weight that was used in the calculation of the metric; the questions were grouped into skill sets and similar cognitive processes called categories. Were then developed two distinct environments: the first, the prototype features an interactive checklist and your individual results. And, second, a system of data management environment for the configuration and editing of the prototype, and the observation and analysis of the survey results. For prototype validation, were invited to access the virtual checklist and answer it, five professionals linked to Cemig's training area. The results confirmed the validity of this instrument application to assess the possible potential of modeling in 2D and RV as learning objects in power substations, as well as provide feedback to developers of virtual environments to improve the system.
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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.
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Research on the mechanisms and processes underlying navigation has traditionally been limited by the practical problems of setting up and controlling navigation in a real-world setting. Thanks to advances in technology, a growing number of researchers are making use of computer-based virtual environments to draw inferences about real-world navigation. However, little research has been done on factors affecting human–computer interactions in navigation tasks. In this study female students completed a virtual route learning task and filled out a battery of questionnaires, which determined levels of computer experience, wayfinding anxiety, neuroticism, extraversion, psychoticism and immersive tendencies as well as their preference for a route or survey strategy. Scores on personality traits and individual differences were then correlated with the time taken to complete the navigation task, the length of path travelled,the velocity of the virtual walk and the number of errors. Navigation performance was significantly influenced by wayfinding anxiety, psychoticism, involvement and overall immersive tendencies and was improved in those participants who adopted a survey strategy. In other words, navigation in virtual environments is effected not only by navigational strategy, but also an individual’s personality, and other factors such as their level of experience with computers. An understanding of these differences is crucial before performance in virtual environments can be generalised to real-world navigational performance.
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Las TIC son inseparables de la museografía in situ e imprescindibles en la museografía en red fija y móvil. En demasiados casos se han instalado prótesis tecnológicas para barnizar de modernidad el espacio cultural, olvidando que la tecnología debe estar al servicio de los contenidos de manera que resulte invisible y perfectamente imbricada con la museografía tradicional. Las interfaces móviles pueden fusionar museo in situ y en red y acompañar a las personas más allá del espacio físico. Esa fusión debe partir de una base de datos narrativa y abierta a obras materiales e inmateriales de otros museos de manera que no se trasladen las limitaciones del museo físico al virtual. En el museo in situ tienen sentido las instalaciones hipermedia inmersivas que faciliten experiencias culturales innovadoras. La interactividad (relaciones virtuales) debe convivir con la interacción (relaciones físicas y personales) y estar al servicio de todas las personas, partiendo de que todas, todos tenemos limitaciones. Trabajar interdisciplinarmente ayuda a comprender mejor el museo para ponerlo al servicio de las personas.
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Relatório de estágio apresentado à Escola Superior de Educação do Instituto Politécnico de Santarém para obtenção do grau de mestre em Educação e Comunicação Multimédia
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Relatório de estágio apresentado à Escola Superior de Educação do Instituto Politécnico de Santarém para obtenção do grau de mestre em Educação e Comunicação Multimédia
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As the semiconductor industry struggles to maintain its momentum down the path following the Moore's Law, three dimensional integrated circuit (3D IC) technology has emerged as a promising solution to achieve higher integration density, better performance, and lower power consumption. However, despite its significant improvement in electrical performance, 3D IC presents several serious physical design challenges. In this dissertation, we investigate physical design methodologies for 3D ICs with primary focus on two areas: low power 3D clock tree design, and reliability degradation modeling and management. Clock trees are essential parts for digital system which dissipate a large amount of power due to high capacitive loads. The majority of existing 3D clock tree designs focus on minimizing the total wire length, which produces sub-optimal results for power optimization. In this dissertation, we formulate a 3D clock tree design flow which directly optimizes for clock power. Besides, we also investigate the design methodology for clock gating a 3D clock tree, which uses shutdown gates to selectively turn off unnecessary clock activities. Different from the common assumption in 2D ICs that shutdown gates are cheap thus can be applied at every clock node, shutdown gates in 3D ICs introduce additional control TSVs, which compete with clock TSVs for placement resources. We explore the design methodologies to produce the optimal allocation and placement for clock and control TSVs so that the clock power is minimized. We show that the proposed synthesis flow saves significant clock power while accounting for available TSV placement area. Vertical integration also brings new reliability challenges including TSV's electromigration (EM) and several other reliability loss mechanisms caused by TSV-induced stress. These reliability loss models involve complex inter-dependencies between electrical and thermal conditions, which have not been investigated in the past. In this dissertation we set up an electrical/thermal/reliability co-simulation framework to capture the transient of reliability loss in 3D ICs. We further derive and validate an analytical reliability objective function that can be integrated into the 3D placement design flow. The reliability aware placement scheme enables co-design and co-optimization of both the electrical and reliability property, thus improves both the circuit's performance and its lifetime. Our electrical/reliability co-design scheme avoids unnecessary design cycles or application of ad-hoc fixes that lead to sub-optimal performance. Vertical integration also enables stacking DRAM on top of CPU, providing high bandwidth and short latency. However, non-uniform voltage fluctuation and local thermal hotspot in CPU layers are coupled into DRAM layers, causing a non-uniform bit-cell leakage (thereby bit flip) distribution. We propose a performance-power-resilience simulation framework to capture DRAM soft error in 3D multi-core CPU systems. In addition, a dynamic resilience management (DRM) scheme is investigated, which adaptively tunes CPU's operating points to adjust DRAM's voltage noise and thermal condition during runtime. The DRM uses dynamic frequency scaling to achieve a resilience borrow-in strategy, which effectively enhances DRAM's resilience without sacrificing performance. The proposed physical design methodologies should act as important building blocks for 3D ICs and push 3D ICs toward mainstream acceptance in the near future.