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- 3D shape prior active contours for an automatic segmentation of a patient specific femur from a CT scanPublication . Almeida, D.; Folgado, J.; Fernandes, P.R.; Ruben, RuiThe following paper describes a novel approach to a medical image segmentation problem. The fully automated computational procedure receives as input images from CT scan exams of the human femur and returns a three dimensional representation of the bone. This patient specific iterative approach is based in 3D active contours without edges, implemented over a level set framework, on which the evolution of the contour depends on local image parameters which can easily be defined by the user but also on a priori information about the volume to segment. This joint approach will lead to an optimal solution convergence of the iterative method. The resulting point cloud can be an excellent starting point for a Finite Element mesh generation and analysis or the basis for a stereolitography for example.
- 3D Video Representation and CodingPublication . Faria, Sergio M.M.; Debono, Carl J.; Nunes, Paulo; M. M. Rodrigues, NunoThe technologies which allow an immersive user experience in 3D environments are rapidly evolving and new services have emerged in various fields of application. Most of these services require the use of 3D video, combined with appropriate display systems. As a consequence, research and development in 3D video continues attracting sustained interest. While stereoscopic viewing is already widely spread, namely in TV and gaming, new displays and applications, such as FTV (Free viewpoint TV), require the use of a larger number of views. Hence, the multiview video format was considered, which uses N views, corresponding to the images captured by N cameras (either real or virtual), with a controlled spatial arrangement. In order to avoid a linear escalation of the bitrate, associated with the use of multiple views, video-plus-depth formats have been proposed. A small number of texture and depth video sequences are used to synthesize intermediate texture views at a different space position, through a depth-image-based rendering (DIBR) technique. This technology allows the use of advanced stereoscopic display processing and to improve support for high-quality autostereoscopic multiview displays. In order to provide a true 3D content and fatigue-free 3D visualization, holoscopic imaging has been introduced as an acquisition and display solution. However, efficient coding schemes for this particular type of content are needed to enable proper storage and delivery of the large amount of data involved in these systems, which is also addressed in this chapter.
- Adaptive Evolutionary Testing: An Adaptive Approach to Search-Based Test Case Generation for Object-Oriented SoftwarePublication . Ribeiro, José Carlos Bregieiro; Zenha-Rela, Mário Alberto; de Vega, Francisco FernándezAdaptive Evolutionary Algorithms are distinguished by their dynamic manipulation of selected parameters during the course of evolving a problem solution; they have an advantage over their static counterparts in that they are more reactive to the unanticipated particulars of the problem. This paper proposes an adaptive strategy for enhancing Genetic Programming-based approaches to automatic test case generation. The main contribution of this study is that of proposing an Adaptive Evolutionary Testing methodology for promoting the introduction of relevant instructions into the generated test cases by means of mutation; the instructions from which the algorithm can choose are ranked, with their rankings being updated every generation in accordance to the feedback obtained from the individuals evaluated in the preceding generation. The experimental studies developed show that the adaptive strategy proposed improves the test case generation algorithm's efficiency considerably, while introducing a negligible computational overhead.
- Analysis of finite oscillating GIX/M(m)//N queueing systemsPublication . Ferreira, Fátima; Pacheco, António; Ribeiro, Helena; Ribeiro, Helena;In this work we investigate oscillating GIX/M(m)//N systems, which are queueing systems whose service mechanism reacts to the congestion of the system; namely, the service rates oscillate between two forms according to the evolution of the number of customers in the system. Resorting to Markov chain embedding, we address the time-dependent and limit analysis of the number of customers in the system at batch prearrivals and seen by customers at their arrival to the system. These results are then used to derive the continuous-time limit distribution of the number of customers in the system. In addition, we provide some numerical examples that illustrate our approach.
- Analysis of Power Quality Disturbances in Industry in the Centre Region of PortugalPublication . Moreira, Licinio; Leitão, Sérgio; Vale, Zita; Galvão, João; Franco Marques, Pedro JoséPower quality issues have taken a more prominent role in power systems over the last years. These issues are of major concern for energy customers, primarily for customers with a widespread use of electronic devices in their manufacturing processes. Even though the quality of service is increasing, customers are becoming more demanding of the energy provider. This research aims to provide some industrial managers the technical support in deciding of investments in the mitigation of power quality disturbances, such as the use of less sensitive devices or the use of interface devices (UPS, DVR...) In order to recommend an appropriate solution, the problem is characterized. The technical and economic influences of the PQ disturbances in the manufacturing processes are assessed resorting to power quality audits in the customer facilities. This research covered a significant number of facilities in several industrial activities.
- Anthocyanins, effects in mitochondria and metabolismPublication . Marques-da-Silva, Dorinda; Rodrigues, Joaquim Rui; Lagoa, RicardoAlterations in mitochondrial function, cellular redox signaling, and metabolism participate in the etiology and progression of different pathological conditions, such as diabetes, cancer, cardiovascular, and neurodegenerative diseases. Epidemiological, preclinical, and clinical studies indicate that anthocyanins afford therapeutic benefits for these pathologies. It is thus important to revise the effects of anthocyanins on mitochondria and metabolism that hold potential for the development of novel health protective methods. The studies available support the ability of certain anthocyanins to prevent damage to mitochondria and to sustain its function. Evidence is more compelling for cyanidin and delphinidin compounds, but promising data could also be found for malvidin, pelargonidin, and protocatechuic acid. Additionally, berry extracts also demonstrated positive outcomes in different models of neurodegeneration, endothelial dysfunction, myocardial damage, metabolic disorders, longevity, and cancer. At the molecular level, major anthocyanins can modulate the expression and activity of mitochondrial proteins, apoptotic and biogenesis factors, antioxidant defenses, inflammation, and the AMPK pathway. Noteworthy, anthocyanins could balance abnormalities in ROS production, respiration, and mitochondrial fragmentation in cells exposed to toxicants or oxidizing agents.
- Anthropometrics and Ergonomics in Pregnant WomenPublication . Almeida, Henrique de Amorim; Teixeira Ascenso, Rita Margarida; Oliveira, EunicePregnancy is a women life event that impacts her own and offspring’s life; surprisingly, few systematic and scientific maternal information is available in the literature for anthropometric and ergonomic purposes. Regarding ergonomics, some authors state that guidelines should be design for pregnant women. These guidelines may consider anthropometric issues such as changes in weight and distribution of mass, which influence mobility, home and labour performance, mood and cognition. Anthropometrics allows the body measurement, but in pregnancy women are sparingly characterized, besides Body Mass Index and few other parameters. Ergonomics not only aids in the design process of work or home layouts, but also contains several evaluation tools to determine the level of risk of musculoskeletal disorders of daily or labour tasks. Some of these tools are very specific and others have certain conditions that should be met before using them. The purpose of this study is to present an overview of guidelines and discuss which anthropometric and ergonomic evaluation tools may be used, and under which conditions can be implemented in pregnant women.
- Application of Renewable Energy—The Case of San Tomé IslandPublication . Ceita, Ludcelma de; Manso, Ricardo; Eugénio, TeresaIn the current context, the energy sector is one of the most important strategic points for the economic transformation of any society. Access to energy is a universal human right and a concern of the state. Whatever national development strategy is defined or implemented, it will always require measures to promote access to energy for all. Although the strong growth of renewable energies worldwide is evident, there are still few studies on their applicability in developing countries. The aim of this study is to contribute to energy sustainability in an emerging country where renewable energies have been little analysed and developed. The country analysed is São Tomé and Príncipe (STP). This paper develops a study on the application of renewable energy, energy sustainability, and clean electricity generation as challenges of the present and ways forward. Aware of the potential of natural resources on the islands of São Tomé and Príncipe, the study follows the following methodology: first phase: a preliminary study to describe the current energy situation on the island; second phase: presentation of a simulation on the use of available resources that has a direct impact on minimising the consumption of fossil fuels on the islands and on the country’s dependence on foreign fuel imports. As a result, the following proposal is made: Utilisation of photovoltaic solar energy with the help of agro-voltaic systems and floating panels, a biomass plant and a transition to electromobility with the help of electric vehicles as energy storage and means of transport.
- Applying Scatter Search to the Location Areas ProblemPublication . Luz, Sónia Maria Almeida da; Vega-Rodríguez, Miguel A.; Gómez-Pulido, Juan A.; Sánchez-Pérez, Juan M.The Location Areas scheme is one of the most common strategies to solve the location management problem, which corresponds to the management of the mobile network configuration with the objective of minimizing the involved costs. This paper presents a new approach that uses a Scatter Search based algorithm applied to the Location Areas scheme as a cost optimization problem. With this work we pretend to analyze and set the main parameters of scatter search, using four distinct test networks and compare our results with those achieved by other authors. This is a new approach to this problem and the results obtained are very encouraging because they show that the proposed technique outperforms the existing methods in the literature.
- AR Mobile Application to Enhance the Birdwatching ExperiencePublication . Venâncio, José; Marto, Anabela; Ascenso, Rita Margarida Teixeira; Rodrigues, Nuno; Gonçalves, Alexandrino José MarquesGuard@Lis application was developed to ease the birdwatching activity. The main purpose was to support the discovery and identification of bird species along a trail, encouraging the preservation and protection of nature. To create a new bird observation perspective since augmented reality features were developed to enhance the experience of birdwatching, ensuring the chance to watch even the most elusive birds. Adding animated 3D models of some birds allows the observation of these species that, for several reasons, may not be easy to encounter in their natural habitat when the user is making the trail. The solution is composed of a multiplatform app and a back-office. It is prepared to create routes with hotspots and improve the bird species list. This first version was designed with a route in the city of Leiria, having specific points along the way, defined for the observation of certain species. Guard@Lis application intends to encourage the didactic and educational facets, so the whole development process of this application was to create a guide that allows users to be able to identify and list the number of bird species found. At this stage, the app allows its users to trail the main historical and tourist points of Leiria and collect the bird species observed.