Thesis (MA--Maori Development) -- AUT University, 2007. / Includes bibliographical references. Also held in print (v, 105 leaves : col. ill. ; 30 cm.) in the Archive at the City Campus (T 305.899442 RAE)

Doctorat en philosophie et lettres / info:eu-repo/semantics/nonPublished

La vidéo sur IP a connu un essor rapide ces dernières années allant de la diffusion télévisuelle en haute qualité via des réseaux dédiés à la diffusion sur internet de contenus vidéo grand public. L’optimisation de l’encodage vidéo H.264/AVC permet aux différents acteurs du marché de se différencier en proposant des solutions pour réduire le débit nécessaire à la représentation d’un flux vidéo ainsi que pour améliorer la qualité perçue par les utilisateurs. C’est dans ce contexte de vidéo professionnelle en haute qualité que s’inscrivent ces travaux de thèse CIFRE réalisés au sein de l’entreprise Digigram, proposant des encodeurs vidéo temps réel pour des diffusions professionnelles en direct. Nous proposons deux solutions de prétraitement pour répondre aux problématiques du secteur de la distribution vidéo. Les deux solutions considèrent les caractéristiques du système visuel humain en exploitant un modèle de JND (Just Noticeable Distortion) définissant des seuils de perception en fonction d’une analyse du contenu des séquences vidéo à encoder. La première solution utilise un préfiltre adaptatif indépendant de l’encodeur, contrôlé par un modèle JND afin d'éliminer le contenu perceptuellement non pertinent et ainsi réduire le débit sans altérer la qualité ressentie. Une analyse approfondie de plusieurs filtres de la littérature, dont le filtre AWA (Adaptive Weighted Averaging) et le filtre bilatéral, nous a également amené à définir deux nouveaux filtres à support étendu qui permettent d’exploiter au mieux les corrélations dans les images haute définition. A l’aide de tests subjectifs, nous montrons que les préfiltres perceptuels proposés permettent en moyenne de diminuer le débit en sortie du codeur d'environ 20% pour une qualité constante en encodage VBR (débit variable) Intra et Inter-image. Finalement, une deuxième solution s’attache à améliorer la qualité perçue dans un contexte d’encodage CBR (débit constant) en intégrant un modèle JND dans l’une des implémentations de la norme H.264/AVC la plus reconnue, le codec x264. Une quantification adaptative perceptuelle est ainsi proposée permettant d’améliorer les performances du codec x264 en améliorant le codage de l’information de contour à moyen et bas débits en encodage intra et inter-image. / The use of digital video over IP has increased exponentially over the last years, due to the development of high-speed networks dedicated to high quality TV transmission as well as the wide development of the nonprofessional video webcast. Optimization of the H.264/AVC encoding process allows manufacturers to offer differentiating encoding solutions, by reducing the bandwidth necessary for transmitting a video sequence at a given quality level, or improving the quality perceived by final users at a fixed bit rate. This thesis was carried out at the company Digigram in a context of professional high quality video. We propose two solutions of preprocessing which consider the characteristics of the human visual system by exploiting a JND profile (Just Noticeable Distortion). A JND model defines perceptual thresholds, below which a distortion cannot be seen, according to the video content. The first solution proposes an adaptive pre-filter independent to the encoder, controlled by a JND profile to reduce the perceptually non-relevant content and so reduce the bitrate while maintaining the perceived quality. By analyzing the state-of-the-art literature, the AWA (Adaptive Weighted Averaging) and Bilateral filters have been selected. Then we define two new filters using a large convolution mask, which enable to better exploit correlations in high-definition video contents. Through subjective tests, we show that the proposed perceptual prefilters give an average bitrate reduction of 20% for the same visual quality in VBR (Variable Bitrate) H.264/AVC Intra and Inter encoding. Finally, the second solution enables to improve the perceived quality in CBR (Constant Bitrate) encoding, by integrating the JND profile into the x264 codec, one of the best implementation of the H.264/AVC standard. Thus, we propose a perceptual adaptive quantization which enhances the x264 performance by improving edge information coding in low and middle bitrate applications.

A growing body of evidence shows that globalization and advances in information and communication technology (ICT) have prompted a revolution in the way work is produced. One of the most notable changes is the establishment of the alternative workplace arrangement (AWA), in which workers have more freedom in their work hours and workplaces. Just as all organizations are not good candidates for AWA adoption, all work types, all employees and all levels of facilities supports are not good candidates for AWA adoption. The main problem is that facility managers have no established tools to assess their readiness for AWA adoption or to select among the possible choices regarding which AWA type is most appropriate considering their organizations' business reasons or objectives of adoption and the current readiness levels. This dissertation resulted in the development of readiness level assessment indicators (RLAI), which measure the initial readiness of high-tech companies for adopting AWAs and the ANN based decision model, which allows facility managers to predict not only an appropriate AWA type, but also an anticipated satisfaction level considering the objectives and the current readiness level. This research has identified significant factors and relative attributes for facility managers to consider when measuring their organization's readiness for AWA adoption. Robust predictive performance of the ANN model shows that the main factors or key determinants have been correctly identified in RLAI and can be used to predict an appropriate AWA type as well as a high-tech company's satisfaction level regarding the AWA adoption.

In March of 2017, New Zealand passed the Te Awa Tupua Act, a law that established the river Whanganui as a legal entity, with the same rights and obligations as a person. This commitment from the New Zealand government gave rise to the possibilities of protecting the ecosystem surrounding the river, but also strengthen the rights of the indigenous people, the Māori's, which consider Whanganui a part of their ancestry and heritage. The aim of this research is to study the ethical argumentation that motivates the recognition of the Whanganui River as a legal entity and connect that with the theoretical approach presented by Mikael Stenmark in Miljöetik och Miljövård: Miljöfrågornas Värderingsmässiga Dimension. The study will also seek to observe how the argumentation is influenced by a minority perspective, more specifically the Māori, and the oppression of their people since the colonization of New Zealand. The theoretical foundations for this study is the environmental ethics framework presented by Stenmark, which can be summed up in three main approaches: anthropocentrism, ecocentrism and biocentrism. A content-oriented ideational analysis lays the groundwork for mapping what moral positions and perceptions that motivates the recognition of the Whanganui River as a legal entity. In addititon, the study has transcribed videos with indigenous people which has been categorized and structured according to the theoretical framework. The analysis concludes that the colonial intergenerational oppression on the Māori's and the observed negative impact on the river corresponds with the well-being of the Māori people. This observed correlation, combined with a modified holistic ecocentrism, is the foundation to which a selected group of Māori's justify and motivate the Te Awa Tupua Act. This essay also problematize that environmental ethics is characterized by a context that need to be supplemented with an updated and multifaceted view of our nature and indigenous people, which draws attention to more positions that in history have not been given enough space in academic context.