Abstract
Como corolário do trabalho de investigação e desenvolvimento, iniciado em 1996, na área das tecnologias da comunicação e dos serviços multimédia em contexto de formação profissional, pretende-se, com este estudo, identificar os principais contributos das ciências e tecnologias da comunicação e da educação nos processos de especificação, concepção, desenvolvimento e utilização do sistema de gestão de aprendizagem Formare, em contexto de formação profissional. Tendo em conta a fundamentação teórica, a participação em projectos de investigação e de inovação e uma vivência prática de mais de 14 anos de actividade na área do ensino a distância, do eLearning e do bLearning em contexto empresarial, desenvolveu-se um modelo conceptual para a nova versão do LMS Formare baseada nos fundamentos da comunicação e da gestão da aprendizagem em ambiente real de utilização. Para além de estudar os fundamentos das Learning Organizations, do Ensino a Distância, da Comunicação Educacional Multimédia, do eLearning, do bLearning e dos seus principais componentes, esta tese focaliza-se na análise de dois estudos de caso, suportados pelo Formare – um, em contexto de Auto-aprendizagem no Campus PT, e outro, em contexto de Aprendizagem Colaborativa na Formação de eFormadores. Pela análise das conclusões de cada um dos estudos de caso realizados, foi possível validar as opções tecnológicas e pedagógicas utilizadas, conhecer a percepção, o grau de utilização e a avaliação pedagógica dos formandos, assim como identificar os principais indicadores de implementação do eLearning nas organizações que aderiram ao LMS Formare. A tese termina com a apresentação dos principais resultados, limitações e conclusões do estudo de investigação, e apresenta um conjunto de considerações futuras nesta área de actividade, esperando contribuir para o desenvolvimento do eLearning em contexto de uma Learning Organization.;This study has grown out of research and development work, begun in 1996, in the field of communication technologies and multimedia services in the context of professional training. It has been designed to identify and report on the factors that determine the way in which communication technologies influence the performance of learners in learning contexts and distributed learning communities and in eLearning and bLearning environments. It is based on the specification and validation experience that has been gained from solutions used in the “Formare” learning management system. A conceptual model for the new version of LMS Formare has been developed on the basis of a number of factors. These include a theoretical framework, research outcomes and the results of innovation projects allied with 14 years professional experience of delivering distance teaching, eLearning and bLearning in a business context, this delivery being based on the principles of communication and the management of learning in real learning environments. In addition to investigating the underlying principles and main components of learning organizations, distance teaching, communication, multimedia education, eLearning and bLearning, this thesis focuses on the analysis of two case studies supported by Formare. The first of these involves self-learning on Campus PT and the second collaborative learning in the context of training eTrainers. For each of the case studies, the technological and pedagogical options employed were analyzed and validated. Data was collected on trainee’s perceptions, degree of use and pedagogical assessments. The main conclusions and indicators involved in implementing eLearning in organizations using LMS Formare were also identified. The thesis draws these various threads together by presenting the main results, limitations and conclusions of the research. It also outlines a number of concerns bearing on future activity in this area, thus attempting to contribute to the development of eLearning in Learning Organizations.

Abstract
Nowadays, there is a wide range of commercial LBMS (Location-Based Mobile Services) available in the market, and a trend towards the display of 3D maps can be clearly observed. Given the complete disparity of ideas and a visible commercial orientation in the industry, the study of the visualization aspects that influence user performance and experience in the exploration of urban environments, using 3D maps, becomes an important issue. Based on a proposed conceptual framework, an online questionnaire was developed and administered in order to measure the real impact of each element. Combining the experimental results with the current state-of-the-art, a new visualization paradigm is defined in a dual specification: "layers" providing relevant visual content to the map, and "functions" providing the necessary functionality.

Abstract
We describe a real-time facade tracking system that uses, as setup information, only two images of a facade, captured on the moment. No more previous information is needed, such as a facade 3D model, dimensions or aspect ratio. Feature points and their local descriptors are extracted from that pair of images and used during the detection and tracking of the facade. Additionally, parallax and topological information is also used in order to increase the overall robustness of the tracking process. Experiments show that the system can detect and track a wide variety of facades, including those that are not entirely planar, partially occluded or have few distinguishable visual landmarks. The reliance on on-the-spot information, alone, makes this system useful for Outdoor Augmented Reality applications, in an Anywhere Augmentation urban context.

Abstract
There are several problems in the computer graphics and visualization domains which require optimization tasks to be performed in order to improve the quality of the overall process. In this context, we propose and describe an innovative optimization methodology and a supporting software framework: i-om. The design goals of the proposed framework were twofold. The first comprises the decoupling, as much as possible, of the optimization process from the application specific processing tasks. In order to attain this goal, we opted to make use of intelligent techniques (i.e. metaheuristics). The second goal is to allow remote operation, and consequently great portability and interoperability, between the optimization tools and the visualization application. To fulfill the latter requirement the proposed framework was designed with the ability to communicate with external application using a specifically developed high level message protocol. The optimization framework was implemented and the paper presents illustrative results demonstrating the usefulness and effectiveness of the proposed approach..

Abstract
Documents on the World Wide Web are dynamic entities. Mainstream information retrieval systems and techniques are primarily focused on the latest version a document, generally ignoring its evolution over time. In this work, we study the term frequency dynamics in web documents over their lifespan. We use the Wikipedia as a document collection because it is a broad and public resource and, more important, because it provides access to the complete revision history of each document. We investigate the progression of similarity values over two projection variables, namely revision order and revision date. Based on this investigation we find that term frequency in encyclopedic documents - i.e. comprehensive and focused on a single topic - exhibits a rapid and steady progression towards the document's current version. The content in early versions quickly becomes very similar to the present version of the document.

Abstract
Strategies developed for database preservation in the past include technology preservation, migration, emulation and the use of a universal virtual computer. In this paper we present a new concept of "Model Migration for Database Preservation". Our proposed approach involves two major activities. First, migrating the database model from conventional relational model to dimensional model and second, calculating the information embedded in code and preserving it instead of preserving the code required to calculate it. This will affect the originality of the database but improve two other characteristics: the information considered relevant is kept in a simple and easier to understand format and the systematic process to preserve the dimensional model is independent of the DBMS details and application logic.