http://hdl.handle.net/10362/1044 DI_MA 2013-05-23T04:33:52Z http://hdl.handle.net/10362/8953 Title: People and object tracking for video annotation Authors: Silva, João Miguel Ferreira da Abstract: Object tracking is a thoroughly researched problem, with a body of associated literature dating at least as far back as the late 1970s. However, and despite the development of some satisfactory real-time trackers, it has not yet seen widespread use. This is not due to a lack of applications for the technology, since several interesting ones exist. In this document, it is postulated that this status quo is due, at least in part, to a lack of easy to use software libraries supporting object tracking. An overview of the problems associated with object tracking is presented and the process of developing one such library is documented. This discussion includes how to overcome problems like heterogeneities in object representations and requirements for training or initial object position hints. Video annotation is the process of associating data with a video’s content. Associating data with a video has numerous applications, ranging from making large video archives or long videos searchable, to enabling discussion about and augmentation of the video’s content. Object tracking is presented as a valid approach to both automatic and manual video annotation, and the integration of the developed object tracking library into an existing video annotator, running on a tablet computer, is described. The challenges involved in designing an interface to support the association of video annotations with tracked objects in real-time are also discussed. In particular, we discuss our interaction approaches to handle moving object selection on live video, which we have called “Hold and Overlay” and “Hold and Speed Up”. In addition, the results of a set of preliminary tests are reported. Description: Dissertação para obtenção do Grau de Mestre em Engenharia Informática 2012-01-01T00:00:00Z http://hdl.handle.net/10362/8865 Title: Changing environmental behaviors through smartphone-based augmented experiences Authors: Santos, Bruno Miguel Inácio Abstract: The use of persuasive technologies can induce changes in attitudes or behaviours, even in individuals that other strategies of persuasion can not reach effectively. In addition, this type of technology can be applied in numerous areas such as health, education, finance, e-business, among others. Although persuasion can be seen as something negative, being used to serve the interests of the persuader rather than the interests of the persuaded, this work aims to achieve a common and shared goal: to change people's behaviour towards the environment. A significant part of the population is still not aware of the sustainability problems that our planet is facing, so it is important to inform people about the theme while persuading them to change their behaviour and acquire proenvironmental attitudes. In this dissertation, work was conducted to alert citizens to this issue in a fun and immersive way using mobile devices, more specifically smartphones, and augmented reality technology that was used to create an environmental scanner. This scanner provided the user with informative insight about the surrounding environment, while highlighting the environmental threats. In addition to augmented reality, pro-environmental actions were positively reinforced using a reward system and a virtual character that interacted and motivated the user. A form of rapid spread through social networks was also created, allowing the persuasive effect to quickly reach a large number of users. Finally was performed a study to assess the success of the work done in changing behaviour towards environmental issues, and to study the influence of augmented reality and positive reinforcement in the changing of behaviours and acquisition of pro-environmental attitudes. Description: Dissertação para obtenção do Grau de Mestrado em Engenharia de Informática 2013-01-01T00:00:00Z http://hdl.handle.net/10362/8745 Title: Improving search engines with open Web-based SKOS vocabularies Authors: Martins, Flávio Nuno Fernandes Abstract: The volume of digital information is increasingly larger and even though organiza-tions are making more of this information available, without the proper tools users have great difficulties in retrieving documents about subjects of interest. Good infor-mation retrieval mechanisms are crucial for answering user information needs. Nowadays, search engines are unavoidable - they are an essential feature in docu-ment management systems. However, achieving good relevancy is a difficult problem particularly when dealing with specific technical domains where vocabulary mismatch problems can be prejudicial. Numerous research works found that exploiting the lexi-cal or semantic relations of terms in a collection attenuates this problem. In this dissertation, we aim to improve search results and user experience by inves-tigating the use of potentially connected Web vocabularies in information retrieval en-gines. In the context of open Web-based SKOS vocabularies we propose a query expan-sion framework implemented in a widely used IR system (Lucene/Solr), and evaluated using standard IR evaluation datasets. The components described in this thesis were applied in the development of a new search system that was integrated with a rapid applications development tool in the context of an internship at Quidgest S.A. Description: Dissertação para obtenção do Grau de Mestre em Engenharia Informática 2012-01-01T00:00:00Z http://hdl.handle.net/10362/8738 Title: A modular distributed transactional memory framework Authors: Vale, Tiago Marques do Abstract: The traditional lock-based concurrency control is complex and error-prone due to its low-level nature and composability challenges. Software transactional memory (STM), inherited from the database world, has risen as an exciting alternative, sparing the programmer from dealing explicitly with such low-level mechanisms. In real world scenarios, software is often faced with requirements such as high availability and scalability, and the solution usually consists on building a distributed system. Given the benefits of STM over traditional concurrency controls, Distributed Software Transactional Memory (DSTM) is now being investigated as an attractive alternative for distributed concurrency control. Our long-term objective is to transparently enable multithreaded applications to execute over a DSTM setting. In this work we intend to pave the way by defining a modular DSTM framework for the Java programming language. We extend an existing, efficient, STM framework with a new software layer to create a DSTM framework. This new layer interacts with the local STM using well-defined interfaces, and allows the implementation of different distributed memory models while providing a non-intrusive, familiar,programming model to applications, unlike any other DSTM framework. Using the proposed DSTM framework we have successfully, and easily, implemented a replicated STM which uses a Certification protocol to commit transactions. An evaluation using common STM benchmarks showcases the efficiency of the replicated STM,and its modularity enables us to provide insight on the relevance of different implementations of the Group Communication System required by the Certification scheme, with respect to performance under different workloads. Description: Dissertação para obtenção do Grau de Mestre em Engenharia Informática 2012-01-01T00:00:00Z