L'hydrogène moléculaire diffus et froid peut être l'un des candidats ultimes à la composante baryonique cachée de la Voie Lactée. Nous décrivons une nouvelle voie de recherche de matière transparente dans le disque et le halo galactiques, qui exploite les effets de diffraction et de réfraction de la lumière des étoiles d'arrière-plan. En simulant le retard de phase induit par un milieu turbulent, nous avons calculé la figure d'éclairement sur la terre d'une source étendue pour une bande passante donnée. Nous montrons que dans les cas favorables, la luminosité apparente d'une étoile d'arrière-plan peut être soumise à des fluctuations stochastiques de l'ordre de quelques pour cent sur une échelle de temps caractéristique de quelques minutes. Nous avons recherché de tels effets de scintillation, induits par du gaz moléculaire de nébuleuses visibles (sombres), ainsi que par d'hypothétiques (invisibles) clumpuscules d'hydrogène moléculaire froid du halo, pendant deux nuits avec le détecteur infra-rouge SOFI au foyer du télescope NTT de l'ESO. Parmi les quelques milliers d'étoiles surveillées, nous avons détecté un objet dont les variations sont compatibles avec un fort effet de scintillation à travers une structure turbulente de la nébuleuse B68. Comme par ailleurs aucun effet de scintillation n'a été trouvé vers le Petit Nuage de Magellan, nous sommes en mesure d'établir des limites supérieures sur la contribution des clumpuscules de gaz à la masse du halo galactique. Nous montrons qu'une surveillance à cadence élevée dans la bande visible avec un télescope de diamètre supérieur à quatre mètres équipé d'une caméra à lecture rapide devrait permettre, avec une exposition de quelque millions (d'heures x étoiles), de quantifier ou de borner d'une façon très significative la contribution du gaz moléculaire turbulent au halo Galactique. / Cool molecular hydrogen H2 may be the ultimate possible constituent to the Milky-Way missing baryon. We describe a new way to search for such transparent matter in the Galactic disc and halo, through the diffractive and refractive effects on the light of background stars. By simulating the phase delay induced by a turbulent medium, we computed the corresponding illumination pattern on the earth for an extended source and a given passband. We show that in favorable cases, the light of a background star can be subjected to stochastic fluctuations of the order of a few percent at a characteristic time scale of a few minutes. We have searched for scintillation induced by molecular gas in visible dark nebulae as well as by hypothetical halo clumpuscules of cool molecular hydrogen (H2_He) during two nights, using the NTT telescope and the IR SOFI detector. Amongst a few thousands of monitored stars, we found one light-curve that is compatible with a strong scintillation effect through a turbulent structure in the B68 nebula. Because no candidate were found toward the SMC, we are able to establish upper limits on the contribution of gas clumpuscules to the Galactic halo mass. We show that the short time-scale monitoring of a few 10^6 star _ hour in the visible band with a >4 m telescope and a fast readout camera should allow one to interestingly quantify or constrain the contribution of turbulent molecular gas to the Galactic halo.

Ces dix dernières années, plusieurs centaines de web-documentaires ont été publiés sur Internet. Si ce format émergent connaît un succès d’estime important auprès des professionnels des médias, son design ne va pas de soi. Dès lors, comment les théories du cinéma documentaire et des médias informatisés éclairent-elles les métamorphoses médiatiques caractéristiques de ces « nouvelles écritures » ? Quels sont les enjeux ontologico-esthétiques et communicationnels d’un documentaire interactif ? Quel rôle et quel pouvoir l’instance d’énonciation doit-elle octroyer à un « spectateur-actant » ? Afin de répondre à ces questions, un état des lieux de la production francophone permet tout d’abord d’établir une typologie des différents modes d’interaction. Ensuite, une approche ethnographique, fondée sur une observation participante du design de B4, fenêtres sur tour, au sein de France Télévisions, interroge l’ensemble des controverses socio-techniques et sémio-pragmatiques qui jalonnent les six mois de conception. Une analyse par théorisation ancrée met en exergue les différentes dimensions d’un Utilisateur Modèle négociées, de manière plus ou moins implicite, par l’ensemble des acteurs. Enfin, les usages supposés du web-documentaire sont confrontés à une évaluation de l’expérience utilisateur. Les jonctions et disjonctions entre les figures d’un Utilisateur Modèle, Statistique et Empirique contribuent in fine à mieux appréhender le design de ce format hybride et non stabilisé. / In the last few years, several hundred interactive documentaries (i-docs) have been published on the Internet. If many media professionals prize the i-doc format, its design remains a challenging feat. Given this, what light do film documentary theories and digital media shed on the mediated metamorphoses that typify the “New Writings” movement? What are the communicational and ontologico-aesthetic issues of i-docs? What role and what power should an instance of enunciation accord to the “actant-spectator”?In response to these questions, our study of the current state of the French-speaking production scene brought to the fore a typology of interaction modes. Following this observation, an ethnographic approach, based on a participant observation method, questioned the overall sociotechnical and semio-graphic issues that marked the six-month design process of an i-doc called B4, fenêtres sur tour for the State-run France Télévisions. A Grounded Theory analysis of the data highlighted the different dimensions of a more or less implicit negotiated Model User used by the actors. Finally, the purported uses of i-docs were questioned in evaluating users’ experience. The junctions and disjunctions involving the interaction of the User, Statistical and Empirical Models contributed to a better grasp of the designing of the hybrid and non-stabilised i-doc format.

O design de interação é uma disciplina de design relativamente nova que pode ser compreendida como o design dos aspectos subjetivos e qualitativos de tudo o que é digital e também interativo. Já o esboço é uma prática muito comum nas disciplinas de design e consiste em um tipo de desenho feito à mão no papel para testar alternativas e comunicá-las para outros profissionais. O design de interação traz novos desafios para a prática de esboços, pois além das telas é necessário representar as ações do usuário e as modificações do sistema ao longo do tempo. Um levantamento da situação atual mostra que as técnicas que existem apresentam limitações importantes e que o assunto ainda é pouco explorado. Portanto o objetivo deste trabalho foi procurar aprimorar os esboços no design de interação, com quatro linhas de ação: analisar as especificidades da prática de esboços no design de interação para compreender as oportunidades de melhoria; desenvolver uma técnica, a ActionSketch, para buscar aproveitar estas oportunidades; verificar se a ActionSketch auxilia no processo de fazer esboços no design de interação; analisar o uso da técnica para procurar compreender como auxilia ou não o processo. Para atingir estes objetivos, adotamos o plano de ação descrito a seguir. Realizamos uma extensa revisão da literatura. Desenvolvemos propostas de técnicas e as refinamos através de iterações de exercícios e de entrevistas com profissionais. Apresentamos a ActionSketch em oficinas para grupos de profissionais da área, onde coletamos resultados do uso da técnica para em seguida analisá-los. A versão da técnica utilizada neste trabalho (v0.8) é composta por quatro partes: quadros, cores, símbolos e regras. Os quadros são uma forma para lidar com a questão temporal, as cores buscam separar as ações do usuário e do sistema, os símbolos são notações para deixar o desenho mais ágil e as regras são boas práticas para orientar o uso da técnica. Esta versão foi apresentada para 24 profissionais em quatro oficinas, seguidas de um período de uso continuado de 18 dias em média e fechado com entrevistas individuais para coletar comentários. Para atingir nosso objetivos a análise dos dados foi feita em dois níveis: um nível mais pragmático, para avaliar a adequação da técnica na sua aplicação prática, e um outro nível mais conceitual, onde pudemos investigar os aspectos mais gerais da prática de esboços, com foco no design de interação. De maneira sucinta os resultados obtidos indicam que a ActionSketch: auxilia o processo cognitivo; facilita a comunicação quando ao menos um designer conhece a técnica; pode ser modificada ou aplicada parcialmente; tem um aprendizado inicial rápido, que pode evoluir de maneira modular; é particularmente adequada para detalhes da interação. Em termos práticos a técnica se mostrou suficientemente adequada para uso e apontou possíveis melhorias. Já no aspecto teórico pudemos verificar a importância da representação da interação nos esboços, que trouxe diversos benefícios para o processo. O trabalho também aponta algumas direções futuras, como uma nova versão da ActionSketch e sua divulgação online de maneira modular e colaborativa. / Interaction design is a relatively new discipline which can be understood as the design of the subjective and qualitative aspects of everything that is both digital and interactive. Sketching is a common practice in design and consists of freehand drawings made on paper to test alternatives and communicate them to other professionals. Interaction design brings new challenges to the practice of sketches, because of the need to represent the interaction as well as the visual layout of the interface. A survey of current practices shows significant limitations and that the subject is still little explored. Therefore the aim of this work was to improve sketching in interaction design, with four lines of action: to analyze the specifics of practice in interaction design sketches to understand the opportunities for improvement; to develop a technique, called ActionSketch, to try to take advantage of these opportunities; to verify if ActionSketch improves the process of sketching in interaction design; to analyze the use of the technique to try to identify how it helps or hinders the process. To achieve these objectives, we adopted the following plan of action. We conducted an extensive literature review. We developed proposals of the technique and refined them through iterations of exercises and interviews with professionals. We then presented ActionSketch in workshops for groups of professionals, from where we collected the results. The version of the technique used in this work (v0.8) consists of four parts: frames, colors, symbols and rules. Frames are a way to deal with the question of representing time, the colors try to evidence the user and system actions, symbols are notations to improve the speed of drawing and rules are good practices that guide the use of the technique. This version was presented to 24 professionals in four workshops, followed by a period of continuous use of 18 days on average and closed with individual interviews to gather feedback. To achieve our objective data analysis was done on two levels: a more pragmatic level, to assess the adequacy of the technique in practical application, and another more conceptual level, where we investigate the more general aspects of the practice of sketches, with focus on interaction design. Briefly the results obtained indicate that ActionSketch: assists the cognitive process; facilitates communication when at least one designer knows the technique; may be modified or partially applied; has a smooth learning curve, which can evolve in a modular way; is particularly adequate for details of the interaction. In practical terms the technique seemed adequate enough for use and indicated some points for improvement. In the theoretical aspect we could verify the importance of representing the interaction in sketches, which brought many benefits to the process. The study also points to some interesting future directions, such as a new version of ActionSketch and the creation of a collaborative site for it\'s publication.

A construção civil é o maior consumidor de recursos naturais do planeta, apropriando-se atualmente de mais da metade da massa total dos materiais extraídos. Neste contexto, o desenvolvimento de sistemas construtivos que proporcionem uma redução do consumo de materiais, conhecida como o princípio da desmaterialização dos edifícios, pode ser uma estratégia para a redução do impacto que a construção civil exerce sobre o ambiente, e um passo em direção a uma economia mais sustentável. A utilização de placas cimentícias para a produção de vedações vem crescendo em várias partes do mundo, seja para a produção de vedações verticais externas, seja como revestimento não aderido sobre vedos existentes, destinados tanto a melhoria estética quanto o desempenho destas fachadas. Uma vedação com placas cimentícias possui em torno de 25% da massa de uma alvenaria tradicional constituída por blocos de concreto para a execução de uma mesma área de vedação vertical, o que pode contribuir ainda para uma redução dos materiais empregados nas estruturas e fundações de um edifício. Apesar da utilização destas placas cimentícias estar coerente com a estratégia da desmaterialização, algumas experiências de vedações executadas com estes componentes manifestaram problemas de manutenção de suas características ao longo do tempo, apresentando fissuras geralmente nas juntas entre placas. Verificando-se as propriedades dos materiais que constituem esta placa cimentícia, principalmente a variação dimensional em relação à temperatura e umidade, constatou-se uma incompatibilidade entre a amplitude das variações dimensionais resultantes e os sistemas de fixação e juntas empregados para a sustentação das mesmas. A avaliação experimental de choque térmico comprovou a influência destas variações para a deterioração das juntas entre as placas. Com base nesta constatação, e em análises dos processos de fixação de placas cimentícias adotados por fornecedores em diversas partes do mundo, foi desenvolvido neste trabalho um novo sistema de fixação para placas cimentícias e de juntas entre estas com capacidade de atender a esta variação dimensional. Realizaram-se protótipos destes componentes os quais foram submetidos a uma avaliação experimental de choque térmico, resultando em nenhuma alteração visível nas juntas e nas superfícies destas placas. Como resultado concluiu-se que a criação de mecanismos que possibilitem acomodação às variações dimensionais, tanto nos dispositivos de fixação destas à estrutura, quanto nos acabamentos das juntas, podem contribuir significativamente para a durabilidade do sistema de vedações constituída por placas cimentícias. / The construction industry is the largest consumer of natural resources in the planet, currently appropriating more than half of mass of the total material extracted. In this context, the development of building systems that provide their dematerialization can be considered as a strategy to reduce the environmental construction impact, and a step toward a more sustainable economy. The use of fiber cement boards for the building production is growing in many parts of the world, to produce external vertical building enclosure or building envelopes, to improving the aesthetics and performance of these facades. A fiber cement board walls weigh around 25% of the traditional masonry mass made of concrete blocks for the same area of vertical building enclosure which can further contribute to a reduction of the materials used in building structures and foundations. Although the use of fiber cement boards complies with the dematerialization strategy, some experiments carried out with these cladding showed maintenance problems over time, usually cracks in the joints between panels. Checking the properties of materials constituting fiber cement boards, especially the dimensional variation due to changing temperature and humidity, there was an incompatibility between these dimensional variations amplitude and fixing systems and joints used to support them. The thermal shock experimental evaluation proved the influence of these variations on joints deterioration. Based on this observation, and on analyzes of the fiber cement suppliers recommendations over the world, a new system for fixing fiber cement board and joints between them was developed in this work with capacity to adapt to this dimensional variation. Prototypes of these components were made and submitted the thermal shock evaluation, resulting in no visible changes in the joints and on the surfaces of these panels. As a result, it was concluded that the creation of mechanisms that allow accommodating the dimensional variations, both in fixing these panels to the structure, and in the joints finishing can significantly contribute to the vertical building enclosure system durability.

Le nuage de points 3D est la donnée obtenue par la majorité des méthodes de numérisation surfacique actuelles. Nous nous intéressons ainsi dans cette thèse à l'utilisation de nuages de points comme unique représentation explicite de surface. Cette thèse présente deux contributions en traitements basés points. La première contribution proposée est une nouvelle méthode de rendu de nuages de points bruts et massifs par opérateurs pyramidaux en espace image. Cette nouvelle méthode s'applique aussi bien à des nuages de points d'objets scannés, que de scènes complexes. La succession d'opérateurs en espace image permet alors de reconstruire en temps réel une surface et d'en estimer des normales, ce qui permet par la suite d'en obtenir un rendu par ombrage. De plus, l'utilisation d'opérateurs pyramidaux en espace image permet d'atteindre des fréquences d'affichage plus élevées d'un ordre de grandeur que l'état de l'art .La deuxième contribution présentée est une nouvelle méthode de simulation numérique en mécanique des fluides en volumes immergés par reconstruction implicite étendue. La méthode proposée se base sur une nouvelle définition de surface implicite par moindres carrés glissants étendue à partir d'un nuage de points. Cette surface est alors utilisée pour définir les conditions aux limites d'un solveur Navier-Stokes par éléments finis en volumes immergés, qui est utilisé pour simuler un écoulement fluide autour de l'objet représenté par le nuage de points. Le solveur est interfacé à un mailleur adaptatif anisotrope qui permet de capturer simultanément la géométrie du nuage de points et l'écoulement à chaque pas de temps de la simulation. / Most surface 3D scanning techniques produce 3D point clouds. This thesis tackles the problem of using points as only explicit surface representation. It presents two contributions in point-based processing. The first contribution is a new raw and massive point cloud screen-space rendering algorithm. This new method can be applied to a wide variety of data from small objects to complex scenes. A sequence of screen-space pyramidal operators is used to reconstruct in real-time a surface and estimate its normals, which are later used to perform deferred shading. In addition, the use of pyramidal operators allows to achieve framerate one order of magnitude higher than state of the art methods. The second proposed contribution is a new immersed boundary computational fluid dynamics method by extended implicit surface reconstruction. The proposed method is based on a new implicit surface definition from a point cloud by extended moving least squares. This surface is then used to define the boundary conditions of a finite-elements immersed boundary transient Navier-Stokes solver, which is used to compute flows around the object sampled by the point cloud. The solver is interfaced with an anisotropic and adaptive meshing algorithm which refines the computational grid around both the geometry defined by point cloud and the flow at each timestep of the simulation.

No description available.

Olivia de Havilland’s legal victory over Warner Brothers in 1943 set a new precedent for labor relations in Hollywood. Not an isolated piece of litigation, the resulting law now is referred to by her name. It was the culmination of long struggle for actors in the studio system for representation and fair treatment under the law. Much of the work during Hollywood’s studio era was undertaken by women. They used their positions on screen both to appeal to their individual audiences. More than any other, the female star defined the pictures they performed in and the brand of the studios that employed them. Hollywood’s studio system bound stars like de Havilland contractually for a period of up to seven years, which was the legal limit at the time. This did not stop studios from abusing those legal limits through loopholes like the suspension clause. In 1943, the suspension clause was what Warner Brothers used to keep Olivia de Havilland beyond the seven calendar years she had worked for the studio. Actors rejoiced when the powerful suspension clause was declared unlawful by de Havilland’s suite. With the De Havilland Law, actors were entitled to independence that had previously be reserved for the lucky few.

Doctor of Philosophy / Radiographic film/screen (F/S) images have a narrow latitude or dynamic range. The film’s ability to record and view all the anatomy within the x-ray field is limited by this narrow dynamic range. The advent of digital radiographic means of storing and displaying radiographic images has improved the ability to record and visualise all of the anatomy. The problem still exists in digital radiography (DR) when radiographic examinations of certain anatomical regions are undertaken. In this work, the value of anatomically shaped radiographic contrast-enhancement masks (RCMs) in improving image contrast and reducing the dynamic range of images in DR was examined. Radiographic contrast-enhancement masks are digital masks that alter the radiographic contrast in DR images. The shape of these masks can be altered by the user. Anatomically shaped RCMs have been modelled on tissue compensation filters (TCFs) commonly used in F/S radiographic examinations. The prime purpose of a TCF is to reduce the dynamic range of photons reaching the image receptor and hence improve radiographic contrast in the resultant image. RCMs affect the dynamic range of the image rather than the energy source of the image, that of the x-ray photons. The research consisted of three distinct phases. The first phase was to examine physical TCFs and their effects on F/S radiographic images. Physical TCFs are used in radiographic F/S examinations to attenuate the x-ray beam to compensate for varying patient tissue thicknesses and/or densities. The effect of the TCF is to reduce resultant radiographic optical density variations in the image, allowing the viewer to observe a range of densities within the image which would otherwise not be visualised. Physical TCFs are commonly aluminium- or lead-based materials that attenuate the x-ray beam. A TCF has varying physical thickness to differentially attenuate the iii beam and is shaped for specific anatomical situations. During this project, various commonly used physical TCFs were examined. Measurements of size and thickness were made. Characteristics of linear attenuation coefficients and half-value thicknesses were delineated for various TCF materials and at various energies. The second phase of the research was to model the physical TCFs in a digital environment and apply the RCMs to DR images. The digital RCMs were created with similar characteristics to mimic the shapes to the physical TCFs. The RCM characteristics can be adjusted by the viewer of the image to suit the anatomy being imaged. Anatomically shaped RCMs were designed to assist in overcoming a limitation when viewing digital radiographic images, that of the dynamic range of the image. Anatomically shaped RCMs differ from other means of controlling the dynamic range of a digital radiographic image. It has been shown that RCMs can reduce the range of optical densities within images with a large dynamic range, to facilitate visualisation of all anatomy within the image. Physical TCFs are used within a specific range of radiographic F/S examinations. Digital radiographic images from this range of examinations were collected from various clinical radiological centres. Anatomically shaped RCMs were applied to the images to improve radiographic contrast of the images. The third phase of the research was to ascertain the benefits of the use of RCMs. Various other methods are currently in use to reduce the dynamic range of digital radiographic images. It is generally accepted that these methods also introduce noise into the image and hence reduce image quality. Quantitative comparisons of noise within the image were undertaken. The anatomically shaped RCMs introduced less noise than current methods designed to reduce the dynamic range of digital radiographic images. It was shown that RCM methods do not affect image quality. Radiographers make subjective assessment of digital radiographic image quality as part of their professional practice. To assess the subjective quality of images enhanced with anatomically shaped RCMs, a survey of radiographers and other iv qualified people was undertaken to ascertain any improvement in RCM-modified images compared to the original images. Participants were provided with eight pairs of image to compare. Questions were asked in the survey as to which image had the better range of optical densities; in which image the anatomy was easiest to visualise; which image had the simplest contrast and density manipulation for optimal visualisation; and which image had the overall highest image quality. Responses from 123 participants were received and analysed. The statistical analysis showed a higher preference by radiographers for the digital radiographic images in which the RCMs had been applied. Comparisons were made between anatomical regions and between patient-related factors of size, age and whether pathology was present in the image or not. The conclusion was drawn that digital RCMs correctly applied to digital radiographic images decrease the dynamic range of the image, allowing the entire anatomy to be visualised in one image. Radiographic contrast in the image can be maximised whilst maintaining image quality. Using RCMs in some digital radiographic examinations, radiographers will be able to present optimised images to referring clinicians. It is envisaged that correctly applied RCMs in certain radiographic examinations will enhance radiographic image quality and possibly lead to improved diagnosis from these images.

This thesis investigates the historically composed political and economic contexts that contributed to the late 1990s commercial renaissance of Korean national cinema and that have sustained the popularity of Korean films among local and regional audiences ever since. Unlike existing approaches to the topic, which emphasise the textual characteristics of national film production, this thesis considers relations between film production, distribution, exhibition, and ancillary markets, as well as Korean cinema’s engagement with international cinemas such as Hollywood, Hong Kong, China and Japan. I argue that following the relaxation of restrictive film policy towards the importation and distribution of foreign films between 1986 and 1988, the subsequent failure of the domestic film industry to compete against international competition precipitated a remarkable shift in consensus regarding the industry’s structure and functions. Due to the loss of distribution rights to foreign films and the rapid decline in ticket sales for Korean films, the continued economic viability of local film companies was under enormous threat by the early 1990s. The government reacted by permitting conglomerates to seize control of the industry and pursue vertical and horizontal integration. During the rest of the decade, Korean cinema was transformed from an art cinema to a commercial entertainment cinema. The 1997/98 economic crisis led to the exit of conglomerate finance, but streamlined film companies were able to withstand the monetary meltdown, continue the domestic revitalisation, and, since the late 1990s, build media empires based on the expansion of Korean cinema throughout the Asian region.

Spinal neurons are important in several aspects motor control. For example, the neurons essential for locomotor movements reside in the ventral spinal cord. In this thesis, different motor control functions are being related to neuronal populations defined by their common expression of a gene. First, a targeted disruption of the gene for vesicular glutamate transporter 2 (Vglut2/ Slc17a6) is described. The mutant animals die at birth because of their inability to breathe. The neuronal network in the brainstem, responsible for inspiration, was shown to become non-functional by the targeted deletion of Vglut2. To our surprise, it was still possible to induce rhythmic activity with normal left/right alternation in spinal cords isolated from VGLUT2-null embryos. Inconsistent reports of Vglut1 expression in the spinal cord made us re-evaluate the Vglut1 and Vglut2 expressions. While Vglut2 expression was widespread in the spinal cord, Vglut1 expression was restricted to a few cells dorsal to the central canal.  Taken together, the data suggest that, glutamatergic signaling is mandatory to drive the bilateral breathing, but not needed for coordination of basal alternating spinal locomotor rhythm. Next, a screen for genes with restricted ventral expression was made. Some of the genes found could be connected to the characteristics of specific neuronal cell populations. For example, fast motor neurons were shown to express the genes Calca and Chodl. Further, we found the Chrna2 expression selectively in putative Renshaw cells. It seems likely that the gene product, the alpha2 subunit of the nicotinergic receptor, could be linked to the unique connection of motor neurons to Renshaw cells. We used the Chrna2 promoter to drive expression of Cre recombinase in a transgenic mouse. The Cre activity was present in most neurons labeled with Renshaw cell markers, which should make it a useful tool for functional studies of this population. The studies presented here show how the genes expressed in subsets of neurons can be used to target populations of neurons for functional studies of neuronal systems.