In the literature there is limited data available on the behaviour of discharges with three dimensional trajectories, although these are the most commonly found in the flows exiting (ocean) outfalls. The necessary three dimensional trajectory data requires cumbersome experimental systems and specialised laboratory setup. Therefore, results from two dimensional trajectory experiments are commonly extrapolated to enable prediction of the flow trajectories and dilutions of discharges that follow three dimensional paths. Importantly, there are also still some aspects of the behaviour of discharges with two dimensional trajectories that are not entirely clear. Non-buoyant flows discharged at an angle to the ambient flow, oblique discharges, behave either like a strongly advected jet or a momentum puff, depending on the discharge angle. Previous research indicated that the transition angle lies between 20° and 40°. Furthermore there is no clear distinction made between the cross sectional flow structure of buoyant and non-buoyant discharges in a cross flow, advected thermals and momentum puffs, and flow prediction models, like Visjet or Corjet, which assume these flows spread at the same rate. The primary objectives of this research are to create a more comprehensive dataset for discharges with three dimensional trajectories; to ascertain the transitional discharge angle that separates flows that behave as a strongly-advected jet or a line momentum puff, and to establish whether there is a difference in the cross sectional concentration profiles of buoyant and non-buoyant discharges in a cross flow. The application of a double Gaussian distribution will be carried out for line advected thermals complimenting earlier work with line momentum puffs. The work feeds into these models and therefore can have an indirect impact on outfall design. A light attenuation system is employed to study the various discharges and the dynamic range is extended by developing a multiple dye system. This enables the evolution of the discharges to be measured over much greater distances. The light attenuation system is described in detail to substantiate the experimental results. The new data shows that the mean tracer distributions for buoyant and non-buoyant discharges in a cross flow are distinct, with the former having a greater peak separation than the latter. This leads to differences in the relationships between peak and centreline concentrations. In addition, while the experimental spreading rates for the two flows are similar, the different forms of the puff and thermal profiles require distinctly different spreading rates for standardised flow profile models, such as the ‘top hat’ models. Differences are also evident in the conversions needed to estimate peak values from the predictions of these standardised profiles and the implications of these differences are discussed in the context of integral models, which are commonly employed to predict the behaviour of such flows. The experimental data from the oblique discharge experiments showed that flows discharged at acute angles up to 32.4° displayed strongly advected jet behaviour, flows discharged at obtuse angles greater than 39.0° displayed momentum puff behaviour, while the intermediate 35.9° discharge appeared as some combination of the aforementioned flows. A comprehensive experimental investigation into the behaviour of discharges with 3D trajectories has been carried out. The flows were released horizontally at an angle of 90°, 45°, or at 22° to the ambient current and the ambient to initial velocity ratio varied from 0.0042 to 0.057, extending the range of initial conditions previously considered. The experiments show limited variability in trajectory and dilution results around the average values. This provides the basis for conducting future experiments with fewer repetitions. The flows with initial discharges angles of 90° and 45° to the ambient motion, display initially line momentum puff and afterwards advected thermal behaviour. The consistent appearance of the characteristic double peaked distributions alleviates previously published concerns about the ability to transfer the understanding gained from discharges that follow a two dimensional path. However, the different orientations of the two peaks within these flow regimes introduces additional complexity into the transition region. In experiments with an initial discharge angle of 22° the double peak distribution did not develop until the flow evolved into an advected thermal, which was consistent with expectations based on the experiments with oblique discharges.

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Steampunk är en subgenre av science fiction. Genren steampunk handlar om alternativ historia under den industriella revolutionen och kännetecknas av en utbredd användning av ångmaskiner. Genren existerar i alla typer av media såsom böcker, film, spel, etc. Steampunk har många fans i hela världen. Det finns många undersökningar som har steampunk som tema, som till exempel en undersökning om ett fantasyelement i steampunkgenren (Karlsson, 2013) eller en analys av steampunkdesign och historia (Tanenbaum, Tanenbaum,  Wakkary, 2012). Samtidigt finns artiklar som flyttar fram genrens gränser och till exempel visar steampunk under vildavästerntiden (Miller & Van Riper, 2011). Liksom dessa undersökningar kommer denna undersökning att studera steampunkgenren och dess ”fanbas”. Syftet med undersökningen är att analysera steampunkgenren och datorspelande i relation till denna genre. Grundidén är att skapa en implementation av sci fi-element i en steampunkkaraktär och visa upp karaktären såväl för personer som känner till genren som för dem som inte känner till steampunk för att se om informanternas reaktionsmönster är likartade. Ska informanterna känna igen sci fi-elementet och ska de acceptera det när det sitter på en steampunkkaraktär? Vidare fokuserar undersökningen på interaktion med karaktären. En enkät kommer att göras för att se huruvida det finns olika reaktionsmönster hos informanterna när de analyserar steampunkkaraktären dels genom 2D-bildmaterial och dels genom en 3D interagerbar artefakt. Undersökningen använder en kvantitativ (Østbye m.fl., 2008:157) nätenkät med kvalitativa (Østbye m.fl., 2008:101) element i form av textsvar. Nätenkäten ska visa informanternas gensvar på de olika kontexterna som visas i bilderna och hur informaterna reagerar på en interaktiv avatarkaraktär. På samma gång ska enkäten visa hur steampunk-fans och icke-fans reagerar på implementationen av sci fi-element på steampunkkaraktären.

Extraire des mesures sur des surfaces est un problème dans de nombreux domaines de recherche. L'archaïsme de certains systèmes ou la cherté d'appareils perfectionnés empêchent l'extraction rapide et robuste de ces paramètres. Pourtant, ils sont essentiels dans de nombreux domaines, comme les paramètres de rugosité qui interviennent dans de nombreux phénomènes physiques ou les valeurs dendrométriques pour l'étude de la bio-diversité. En parallèle, l'utilisation et la production de contenus 3D se développent considérablement ces dernières années dans des domaines très divers. Le but de cette thèse est donc d'utiliser toutes ces innovations dans le domaine de la reconstruction 3D et de les appliquer à la mesure de paramètres de surfaces. Pour cela, il est nécessaire de créer une chaîne complète de reconstruction 3D, n'utilisant que des images prises sans contrainte dans le but d'être accessible au plus grand nombre. Dans cette chaîne nous utilisons des algorithmes de stéréo-vision robustes produisant, pour chaque couple d'images, un nuage de points. Après le passage de ces nuages dans un référentiel commun, une étape de filtrage des points 3D et de suppression des redondances est nécessaire. Une étape de lissage permet d'obtenir le nuage final. Pour justifier des bons résultats obtenus, une étape de validation nous a permis de vérifier et d'étudier la robustesse de la chaîne de traitements développée. Enfin, les paramètres de rugosités et dendrométriques seront extraits. Nous étudierons dans ces deux cas, comment extraire ces informations et leurs utilisations / Extracting measures on surfaces is a problem in many areas of research. The archaism of some systems or the costliness of sophisticated devices prevent the fast and robust extraction of these parameters. Yet these measures are essential in many areas, such as roughness parameters involved in many physical phenomena or dendrometric values for the study of biodiversity. In parallel, the use and production of 3D content has grown dramatically this past year in very diverse domains. The purpose of this thesis is to use these innovations in the context of surfaces parameter measurements. It is necessary to create a complete chain of 3D reconstruction, using pictures taken without constraint, in order to be open to as many people. This chain uses robust stereo-vision algorithms in order to produce a point cloud for each pair of images. After the generation of these point cloud in the same geometric frame, a filtering step of 3D points and a deletion step of redundancies are necessary and a smoothing step allows us to obtain the final point cloud. To reveal the good results, a validation step has enabled us to verify and investigate the robustness of the developed chain. The roughness and dendrometric parameters are finally extracted. We will study in both cases, how to extract this information and their uses

Notre recherche concerne les nouvelles approches qui améliorent l’exploration 3D dans des environnements virtuels pour les utilisateurs. De ce fait, nous nous focalisons sur la conception de nouvelles techniques d’interaction 3D transversales, qui sont simples, efficaces et bénéficient de la nouvelle périphérique d’entrée, comme les interfaces tactiles. Notre approche permet aux utilisateurs d’effectuer une interaction 3D complexes à l’aide d’entrée touche simple et multiples. Les utilisateurs effectuer des gestes en utilisent des touches simple et des esquisses pour interagir avec le contenu. Pour faire des conclusions sur la facilité d’utilisation de nos interfaces nous évaluons les techniques d’interaction en menant des études utilisateurs. Ensuite, nous adoptons des techniques traditionnelles et d’illustration de visualisation pour mettre en avant des caractéristiques différentes de l’objet en cible tout en préservant les informations de contexte. En outre, nous proposons de nouvelles méthodes de collaboration entre les utilisateurs qui interagissent avec les données 3D en utilisant la technologie divers, comme des périphériques mobiles de petite taille et des environnements virtuels immersifs. / Our research concerns the investigation of new approaches that enhance 3D exploration in virtual environments for users. Thereby, we concentrate on design of novel transversal 3D interaction techniques that are simple, efficient and benefit from new input technology, like tactile interfaces. Our approach allows users to perform complex 3D interaction using single and multiple 2D touch input. Users carry out simple touch, stroke or sketch-based gestures to interact with content. To draw conclusions about the usability of our interfaces we evaluate the interaction techniques by conducting users studies. In addition, we adopt different traditional and illustrative visualization techniques to highlight object characteristics in focus while preserving context information. Furthermore, we propose new methods for collaboration between users, who interact together with 3D data using varying technology, from small mobile devices to immersive virtual environments.

Computer vision is a research field in which images are the main object of study. One of its category of problems is shape description. Object classification is one important example of applications using shape descriptors. Usually, these processes were performed on 2D images. With the large-scale development of new technologies and the affordable price of equipment that generates 3D images, computer vision has adapted to this new scenario, expanding the classic 2D methods to 3D. However, it is important to highlight that 2D methods are mostly dependent on the variation of illumination and color, while 3D sensors provide depth, structure/3D shape and topological information beyond color. Thus, different methods of shape descriptors and robust attributes extraction were studied, from which new attribute extraction methods have been proposed and described based on 3D data. The results obtained from well known public datasets have demonstrated their efficiency and that they compete with other state-of-the-art methods in this area: the RPHSD (a method proposed in this dissertation), achieved 85:4% of accuracy on the University of Washington RGB-D dataset, being the second best accuracy on this dataset; the COMSD (another proposed method) has achieved 82:3% of accuracy, standing at the seventh position in the rank; and the CNSD (another proposed method) at the ninth position. Also, the RPHSD and COMSD methods have relatively small processing complexity, so they achieve high accuracy with low computing time. / Visão computacional é uma área de pesquisa em que as imagens são o principal objeto de estudo. Um dos problemas abordados é o da descrição de formatos (em inglês, shapes). Classificação de objetos é um importante exemplo de aplicação que usa descritores de shapes. Classicamente, esses processos eram realizados em imagens 2D. Com o desenvolvimento em larga escala de novas tecnologias e o barateamento dos equipamentos que geram imagens 3D, a visão computacional se adaptou para este novo cenário, expandindo os métodos 2D clássicos para 3D. Entretanto, estes métodos são, majoritariamente, dependentes da variação de iluminação e de cor, enquanto os sensores 3D fornecem informações de profundidade, shape 3D e topologia, além da cor. Assim, foram estudados diferentes métodos de classificação de objetos e extração de atributos robustos, onde a partir destes são propostos e descritos novos métodos de extração de atributos a partir de dados 3D. Os resultados obtidos utilizando bases de dados 3D públicas conhecidas demonstraram a eficiência dos métodos propóstos e que os mesmos competem com outros métodos no estado-da-arte: o RPHSD (um dos métodos propostos) atingiu 85:4% de acurácia, sendo a segunda maior acurácia neste banco de dados; o COMSD (outro método proposto) atingiu 82:3% de acurácia, se posicionando na sétima posição do ranking; e o CNSD (outro método proposto) em nono lugar. Além disso, os métodos RPHSD têm uma complexidade de processamento relativamente baixa. Assim, eles atingem uma alta acurácia com um pequeno tempo de processamento.