Modelling virtual urban environments

In this paper, we explore the way in which virtual reality (VR) systems are being broadened to encompass a wide array of virtual worlds, many of which have immediate applicability to understanding urban issues through geocomputation. Wesketch distinctions between immersive, semi-immersive and remote environments in which single and multiple users interact in a variety of ways. We show how suchenvironments might be modelled in terms of ways of navigating within, processes of decision-making which link users to one another, analytic functions that users have to make sense of the environment, and functions through which users can manipulate, change, or design their world. We illustrate these ideas using four exemplars that we have under construction: a multi-user internet GIS for Londonwith extensive links to 3-d, video, text and related media, an exploration of optimal retail location using a semi-immersive visualisation in which experts can explore such problems, a virtual urban world in which remote users as avatars can manipulate urban designs, and an approach to simulating such virtual worlds through morphological modelling based on the digital record of the entire decision-making process through which such worlds are built

Geoinformation, Geotechnology, and Geoplanning in the 1990s

Over the last decade, there have been some significant changes in the geographic information available to support those involved in spatial planning and policy-making in different contexts. Moreover, developments have occurred apace in the technology with which to handle geoinformation. This paper provides an overview of trends during the 1990s in data provision, in the technology required to manipulate and analyse spatial information, and in the domain of planning where applications of computer technology in the processing of geodata are prominent. It draws largely on experience in western Europe, and in the UK and the Netherlands in particular, and suggests that there are a number of pressures for a strengthened role for geotechnology in geoplanning in the years ahead

Asymmetric collaboration in virtual reality: A taxonomy of asymmetric interfaces for collaborative immersive learning

It has been established that Virtual Reality (VR) possesses certain qualities for educational purposes. These include the ability to place the learner at the location or in the perspective that the desired knowledge exists (e.g., travelling to another planet or shrinking to miniature size to observe internal anatomy). VR is also considered to contribute with enriching the curricular content, promoting active forms of learning, performance assessment of high validity, and provide the opportunity to teach applied academic knowledge in life-like situations. In regards to teaching mathematics and geometry, three key affordances have been identified; interactive manipulation and construction of three-dimensional geometry, comprehension of spatial relationships, and rectification of abstract problems. Safety protocols and practical guidelines from classroom experimentation have also been formulated by various research projects. In this manuscript, asymmetrical immersive VR in education will be reviewed, as it is relevant for the narrative of learning situations where multiple students use the technology together. As an example, in mathematics, asymmetric VR could be used in contexts where unknown variables must be found in collaboration. The purpose of the narrative literature review is to gain a greater understanding of how asymmetric game mechanics has influence on communication and collaboration between learners. To map the dynamics of this type of learning activity, a taxonomy will be presented. Since VR is still under development in terms of hardware and software, it is important that the current and future technical possibilities are described in a conceptual manner, as well as conclude on optimal coupling between communication dynamics and collaboration mechanics

Collaborative block design task for assessing pair performance in virtual reality and reality

Collaborative problem solving is more important than ever as the problems we try to solve become increasingly complex. Meanwhile, personal and professional communication has moved from face-to-face to computer-mediated environments, but there is little understanding on how the characteristics of these environments affect the quality of interaction and joint problem solving. To develop this understanding, methods are needed for measuring success of collaboration. For this purpose, we created a collaborative block design task intended to evaluate and quantify pair performance. In this task, participants need to share information to complete visuospatial puzzles. Two versions of the task are described: a physical version and one that can be completed in virtual reality. A preliminary study was conducted with the physical version (N = 18 pairs) and the results were used to develop the task for a second study in virtual reality (N = 31 pairs). Performance measures were developed for the task, and we found that pair performance was normally distributed and positively associated with visuospatial skills, but not with other participant-specific background factors. The task specifications are released for the research community to apply and adapt in the study of computer-mediated social interaction.Peer reviewe

Conceitos e métodos para apoio ao desenvolvimento e avaliação de colaboração remota utilizando realidade aumentada

Remote Collaboration using Augmented Reality (AR) shows great potential to establish a common ground in physically distributed scenarios where team-members need to achieve a shared goal. However, most research efforts in this field have been devoted to experiment with the enabling technology and propose methods to support its development. As the field evolves, evaluation and characterization of the collaborative process become an essential, but difficult endeavor, to better understand the contributions of AR. In this thesis, we conducted a critical analysis to identify the main limitations and opportunities of the field, while situating its maturity and proposing a roadmap of important research actions. Next, a human-centered design methodology was adopted, involving industrial partners to probe how AR could support their needs during remote maintenance. These outcomes were combined with literature methods into an AR-prototype and its evaluation was performed through a user study. From this, it became clear the necessity to perform a deep reflection in order to better understand the dimensions that influence and must/should be considered in Collaborative AR. Hence, a conceptual model and a humancentered taxonomy were proposed to foster systematization of perspectives. Based on the model proposed, an evaluation framework for contextualized data gathering and analysis was developed, allowing support the design and performance of distributed evaluations in a more informed and complete manner. To instantiate this vision, the CAPTURE toolkit was created, providing an additional perspective based on selected dimensions of collaboration and pre-defined measurements to obtain “in situ” data about them, which can be analyzed using an integrated visualization dashboard. The toolkit successfully supported evaluations of several team-members during tasks of remote maintenance mediated by AR. Thus, showing its versatility and potential in eliciting a comprehensive characterization of the added value of AR in real-life situations, establishing itself as a generalpurpose solution, potentially applicable to a wider range of collaborative scenarios.Colaboração Remota utilizando Realidade Aumentada (RA) apresenta um enorme potencial para estabelecer um entendimento comum em cenários onde membros de uma equipa fisicamente distribuídos precisam de atingir um objetivo comum. No entanto, a maioria dos esforços de investigação tem-se focado nos aspetos tecnológicos, em fazer experiências e propor métodos para apoiar seu desenvolvimento. À medida que a área evolui, a avaliação e caracterização do processo colaborativo tornam-se um esforço essencial, mas difícil, para compreender as contribuições da RA. Nesta dissertação, realizámos uma análise crítica para identificar as principais limitações e oportunidades da área, ao mesmo tempo em que situámos a sua maturidade e propomos um mapa com direções de investigação importantes. De seguida, foi adotada uma metodologia de Design Centrado no Humano, envolvendo parceiros industriais de forma a compreender como a RA poderia responder às suas necessidades em manutenção remota. Estes resultados foram combinados com métodos da literatura num protótipo de RA e a sua avaliação foi realizada com um caso de estudo. Ficou então clara a necessidade de realizar uma reflexão profunda para melhor compreender as dimensões que influenciam e devem ser consideradas na RA Colaborativa. Foram então propostos um modelo conceptual e uma taxonomia centrada no ser humano para promover a sistematização de perspetivas. Com base no modelo proposto, foi desenvolvido um framework de avaliação para recolha e análise de dados contextualizados, permitindo apoiar o desenho e a realização de avaliações distribuídas de forma mais informada e completa. Para instanciar esta visão, o CAPTURE toolkit foi criado, fornecendo uma perspetiva adicional com base em dimensões de colaboração e medidas predefinidas para obter dados in situ, que podem ser analisados utilizando o painel de visualização integrado. O toolkit permitiu avaliar com sucesso vários colaboradores durante a realização de tarefas de manutenção remota apoiada por RA, permitindo mostrar a sua versatilidade e potencial em obter uma caracterização abrangente do valor acrescentado da RA em situações da vida real. Sendo assim, estabelece-se como uma solução genérica, potencialmente aplicável a uma gama diversificada de cenários colaborativos.Programa Doutoral em Engenharia Informátic

Group-Lasso on Splines for Spectrum Cartography

The unceasing demand for continuous situational awareness calls for innovative and large-scale signal processing algorithms, complemented by collaborative and adaptive sensing platforms to accomplish the objectives of layered sensing and control. Towards this goal, the present paper develops a spline-based approach to field estimation, which relies on a basis expansion model of the field of interest. The model entails known bases, weighted by generic functions estimated from the field's noisy samples. A novel field estimator is developed based on a regularized variational least-squares (LS) criterion that yields finitely-parameterized (function) estimates spanned by thin-plate splines. Robustness considerations motivate well the adoption of an overcomplete set of (possibly overlapping) basis functions, while a sparsifying regularizer augmenting the LS cost endows the estimator with the ability to select a few of these bases that ``better'' explain the data. This parsimonious field representation becomes possible, because the sparsity-aware spline-based method of this paper induces a group-Lasso estimator for the coefficients of the thin-plate spline expansions per basis. A distributed algorithm is also developed to obtain the group-Lasso estimator using a network of wireless sensors, or, using multiple processors to balance the load of a single computational unit. The novel spline-based approach is motivated by a spectrum cartography application, in which a set of sensing cognitive radios collaborate to estimate the distribution of RF power in space and frequency. Simulated tests corroborate that the estimated power spectrum density atlas yields the desired RF state awareness, since the maps reveal spatial locations where idle frequency bands can be reused for transmission, even when fading and shadowing effects are pronounced.Comment: Submitted to IEEE Transactions on Signal Processin