Disparity compensation using geometric transforms

This dissertation describes the research and development of some techniques to enhance the disparity compensation in 3D video compression algorithms. Disparity compensation is usually performed using a block matching technique between views, disregarding the various levels of disparity present for objects at different depths in the scene. An alternative coding scheme is proposed, taking advantage of the cameras setup information and the object’s depth in the scene, to compensate more complex spatial distortions, being able to improve disparity compensation even with convergent cameras. In order to perform a more accurate disparity compensation, the reference picture list is enriched with additional geometrically transformed images, for the most relevant object’s levels of depth in the scene, resulting from projections of one view to another. This scheme can be implemented in any state-of-the-art video codec, as H.264/AVC or HEVC, in order to improve the disparity matching accuracy between views. Experimental results, using MV-HEVC extension, show the efficiency of the proposed method for coding stereo video, presenting bitrate savings up to 2.87%, for convergent camera sequences, and 1.52% for parallel camera sequences. Also a method to choose the geometrically transformed inter view reference pictures was developed, in order to reduce unnecessary overhead for unused reference pictures. By selecting and adding to the reference picture list, only the most useful pictures, all results improved, presenting bitrate savings up to 3.06% for convergent camera sequences, and 2% for parallel camera sequences

Am I aligned with how I portray myself? The effect of perceived brand hypocrisy on consumer emotions

Dissertation presented as the partial requirement for obtaining a Master's degree in Statistics and Information Management, specialization in Marketing Research and CRMAs consumer needs and demands increase, brands that misbehave may face adverse reactions that negatively impact the consumer-brand relationship. In this study, we investigate how differences between a brand’s portrayed image and how it behaves may lead to the appearance of Brand Hypocrisy perceptions, and ultimately, give rise to Brand Hate and a Desire for Revenge. A 2 (Brand Hypocrisy Exposure: Yes, No) × 2 (Brand Type: Product, Service) experiment was implemented, and a total of 204 consumers were randomly assigned to one of four case conditions. To analyze the main effects between the independent and dependent variables, analysis of variance (ANOVA) was used, PROCESS was used to test moderation, and to confirm the effectiveness of the experimental manipulation, an independent samples t-test was also applied. The results showed that consumers that have been exposed to Brand Hypocrisy were more likely to elicit higher levels of Brand Hate and Desire for Revenge. However, if consumers showed higher levels of Self-Brand Connection, it shielded brands of one of these negative outcomes. Overall, the study contributes to the literature on brand perceptions and negative consumer reactions by providing new outcomes and finding that Self-Brand Connection can help brand managers mitigate Brand Hate

Otimização do modo de registo de dados durante a técnica de Perfusão Isolada dos Membros

Cancer is a disease in which the cells of our organism, due to mutations in their DNA, divide without control and acquire malignant properties and, during this process of uncontrolled division, invade other tissues and don’t die. Cancer cells have the ability to spread through the body using the circulatory and lymphatic systems, giving rise to metastases. With regard to cutaneous neoplasms, the therapy chosen for surgically dispersed and unresectable metastases involved amputation of the sick limb, however, many complications and short time intervals between treatment and the appearance of new lesions were associated. In 1957, an innovative technique emerges and proves to be extremely effective and avoids limb amputation: Isolated Limb Perfusion performed with Melphalan and TNF-α. The main objective of this procedure is to isolate the limb affected by the disease from the systemic circulation so that it is possible to administer very high doses of chemotherapy without any collateral damage. In this sense, it is necessary to have a control of blood leaks from the limb to the systemic circulation, in order to ensure that no other organ or tissue is compromised. The Portuguese Institute of Oncology (IPO) of Porto is one of the worldwide institutions that practice this type of surgical interventions, reporting an annual increase in the number of occurrences year after year. Consequently, this progressive increase and coupled with the fact that this leak control is impractical and time-consuming, led this institution to join Instituto Superior de Engenharia do Porto (ISEP) to develop an application that, in combination with an extracorporeal counter equipment called Neoprobe Gamma Detector System is able to record the values obtained automatically and allow monitoring possible leaks

Acquisition of horizon wind energy by EdP

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and EconomicsAt the beginning of 2007, EdP, a Portuguese electricity utility was studying the potential acquisition of Horizon Wind Energy. Owned by Goldman Sachs, Horizon was a relevant player in the wind energy industry with capacity installed in USA. Requiring that EdP more than doubles its investments in renewables until 2010, this consolidation move would place the company as the 4th largest operator in the world.. Governmental support is just one of the factors that has to be analyzed in this deal, since the strategic implications and risks involved may determine the approval or refusal to go forward with the acquisition, and the price to be paid for the American company

Scalable light field representation and coding

This Thesis aims to advance the state-of-the-art in light field representation and coding. In this context, proposals to improve functionalities like light field random access and scalability are also presented. As the light field representation constrains the coding approach to be used, several light field coding techniques to exploit the inherent characteristics of the most popular types of light field representations are proposed and studied, which are normally based on micro-images or sub-aperture-images. To encode micro-images, two solutions are proposed, aiming to exploit the redundancy between neighboring micro-images using a high order prediction model, where the model parameters are either explicitly transmitted or inferred at the decoder, respectively. In both cases, the proposed solutions are able to outperform low order prediction solutions. To encode sub-aperture-images, an HEVC-based solution that exploits their inherent intra and inter redundancies is proposed. In this case, the light field image is encoded as a pseudo video sequence, where the scanning order is signaled, allowing the encoder and decoder to optimize the reference picture lists to improve coding efficiency. A novel hybrid light field representation coding approach is also proposed, by exploiting the combined use of both micro-image and sub-aperture-image representation types, instead of using each representation individually. In order to aid the fast deployment of the light field technology, this Thesis also proposes scalable coding and representation approaches that enable adequate compatibility with legacy displays (e.g., 2D, stereoscopic or multiview) and with future light field displays, while maintaining high coding efficiency. Additionally, viewpoint random access, allowing to improve the light field navigation and to reduce the decoding delay, is also enabled with a flexible trade-off between coding efficiency and viewpoint random access.Esta Tese tem como objetivo avançar o estado da arte em representação e codificação de campos de luz. Neste contexto, são também apresentadas propostas para melhorar funcionalidades como o acesso aleatório ao campo de luz e a escalabilidade. Como a representação do campo de luz limita a abordagem de codificação a ser utilizada, são propostas e estudadas várias técnicas de codificação de campos de luz para explorar as características inerentes aos seus tipos mais populares de representação, que são normalmente baseadas em micro-imagens ou imagens de sub-abertura. Para codificar as micro-imagens, são propostas duas soluções, visando explorar a redundância entre micro-imagens vizinhas utilizando um modelo de predição de alta ordem, onde os parâmetros do modelo são explicitamente transmitidos ou inferidos no decodificador, respetivamente. Em ambos os casos, as soluções propostas são capazes de superar as soluções de predição de baixa ordem. Para codificar imagens de sub-abertura, é proposta uma solução baseada em HEVC que explora a inerente redundância intra e inter deste tipo de imagens. Neste caso, a imagem do campo de luz é codificada como uma pseudo-sequência de vídeo, onde a ordem de varrimento é sinalizada, permitindo ao codificador e decodificador otimizar as listas de imagens de referência para melhorar a eficiência da codificação. Também é proposta uma nova abordagem de codificação baseada na representação híbrida do campo de luz, explorando o uso combinado dos tipos de representação de micro-imagem e sub-imagem, em vez de usar cada representação individualmente. A fim de facilitar a rápida implantação da tecnologia de campo de luz, esta Tese também propõe abordagens escaláveis de codificação e representação que permitem uma compatibilidade adequada com monitores tradicionais (e.g., 2D, estereoscópicos ou multivista) e com futuros monitores de campo de luz, mantendo ao mesmo tempo uma alta eficiência de codificação. Além disso, o acesso aleatório de pontos de vista, permitindo melhorar a navegação no campo de luz e reduzir o atraso na descodificação, também é permitido com um equilíbrio flexível entre eficiência de codificação e acesso aleatório de pontos de vista

Quantification of reachable attractors in asynchronous discrete dynamics

Motivation: Models of discrete concurrent systems often lead to huge and complex state transition graphs that represent their dynamics. This makes difficult to analyse dynamical properties. In particular, for logical models of biological regulatory networks, it is of real interest to study attractors and their reachability from specific initial conditions, i.e. to assess the potential asymptotical behaviours of the system. Beyond the identification of the reachable attractors, we propose to quantify this reachability. Results: Relying on the structure of the state transition graph, we estimate the probability of each attractor reachable from a given initial condition or from a portion of the state space. First, we present a quasi-exact solution with an original algorithm called Firefront, based on the exhaustive exploration of the reachable state space. Then, we introduce an adapted version of Monte Carlo simulation algorithm, termed Avatar, better suited to larger models. Firefront and Avatar methods are validated and compared to other related approaches, using as test cases logical models of synthetic and biological networks. Availability: Both algorithms are implemented as Perl scripts that can be freely downloaded from http://compbio.igc.gulbenkian.pt/nmd/node/59 along with Supplementary Material.Comment: 19 pages, 2 figures, 2 algorithms and 2 table

Práticas de Gestão Estratégica de Recursos Humanos: Estudo de Caso

A gestão sustentou a ideia de sucessos através da vantagem tecnológica e do capital financeiro. Hoje a gestão pensa em novas fontes de vantagem competitiva e encontra na Gestão Estratégica de Recursos Humanos uma resposta possível e sustentada, se colocar as pessoas no centro da organização, apelando à autonomia, à criatividade, ao talento, a estímulos, a aspirações individuais e cooperativas, e considera que são as pessoas que fazem as grandes empresas. Este artigo que tem por base uma dissertação de mestrado segue a metodologia de um estudo de caso cuja recolha de dados foi realizada tendo por base diversas fontes: análise documental, observação directa, questionário e entrevista. Verificamos que a Empresa adopta a visão soft ao gerir os Recursos Humanos como activos valorizados e como fonte de vantagem competitiva. A realidade empresarial revela aspectos quantitativos e calculistas do modelo hard. A Gestão de Recursos Humanos evidencia um misto de práticas e políticas soft e hard que estrategicamente alinham as pessoas. As diversas práticas e políticas de gestão de Recursos Humanos alinham estrategicamente as pessoas com os objectivos organizacionais de forma a obter-se a melhor performance. Face ao estudo empírico realizado constatamos que existe alguma dificuldade em delimitar e verificar a prevalência dos dois modelos: soft numa lógica de investimento, e modelo hard numa lógica de custo. Observa-se a confluência dos dois modelos, prevalecendo mais um ou outro conforme as políticas de RH

Uso da prototipagem rápida no projecto e produção de motores de combustão interna

Os motores de combustão interna são constituídos por peças de elevada complexidade, tal como a cabeça do motor. Nesta peça existem várias condutas (admissão, escape, arrefecimento), vários postiços (sedes e guias das válvulas de admissão e escape) e vários acessórios estão a ela ligada ou fazem dela parte, tal como a vela e todo o sistema de distribuição constituído por árvore de cames, balanceiros, válvulas e molas. Com tal complexidade torna-se difícil fazer o projecto, mas principalmente efectuar a produção da peça. Em particular as condutas constituem zonas de difícil acesso para remoção de material, e impõem limitações de execução. A prototipagem rápida pode ajudar tanto na fase de projecto como na de produção. Técnicas diferentes de prototipagem rápida foram aplicadas à produção de peças fundidas, de modo a serem aplicadas no motor.Fundação para a Ciência e a Tecnologia (FCT) - POCI/EME/59186/2004