La compréhension orale est une activité langagière complexe, redoutée par les élèves francophones, qui obtiennent de faibles résultats. Face à ces difficultés, les autorités éducatives encouragent les professeurs à utiliser les TICE (Technologies de l'Information et la Communication pour l'Enseignement), dont ils ne perçoivent pas toujours les plus-values. Partant de l'hypothèse que pour améliorer les compétences des élèves il faudrait entraîner ceux-ci en développant des stratégies d'apprentissage, en particulier métacognitives, cette étude a cherché comment intégrer le baladeur vidéo numérique pour entraîner à la compréhension orale. Elle fait état d'une expérimentation menée pendant quatre mois dans quatre classes de première en lycée général, chaque groupe travaillant selon un protocole différent, visant à tester l'effet de l'usage de baladeurs vidéo numériques et du développement explicite de stratégies de compréhension orale. On a cherché dans quelle mesure l'usage de l'outil numérique utilisé pouvait être porteur de motivation et constaté qu'il permettait aux élèves de s'investir davantage dans l'activité, mais sans que ceci améliore nécessairement l'apprentissage. Au travers des parcours créés sur les baladeurs, on a cherché à développer des stratégies cognitives et métacognitives, et observé que l'usage des élèves ne suivait pas toujours les usages prescrits, ainsi que des changements dans la classe en termes d'interactions. L'usage du baladeur et des stratégies développées a eu un impact sur les performances des élèves en termes de métacognition et perception, mais pas en termes de niveau de compréhension. Ces résultats amènent à s'interroger sur les manières de soutenir et entraîner les apprenants à la compréhension orale en anglais, et à aborder plus généralement la problématique des aides dans l'apprentissage des langues médiatisé par les technologies. / Listening is a complex language competence, dreadful to French students, whose results are low. In reaction to those difficulties, educational authorities encourage teachers to use digital tools whose advantages are not always clear for teachers. Assuming that students should be trained with learning strategies, particularly metacognitive strategies, this study tried to assess how digital video players could develop listening skills. It relates an experiment which took place in a French high school during a four-month period, with four groups working differently, in order to test the use of digital video players and of explicit listening strategies. The use of digital video players played a role in the motivation of students as it enabled them to be engaged in the activity, which did not necessarily mean they were learning more. Guided work on the video players aimed at developing cognitive and metacognitive strategies, and we observed the way students complied with the guidelines they had been given, as well as the changes introduced in the classroom in terms of interactions. The use of digital video players and strategies had an impact on the students' skills in terms of metacognition and perception, but not on the students' listening performance. Those results question the way listeners should be helped and trained when listening to English texts, and more broadly how to deal with the issue of technology-mediated language learning.

A popularização de aplicativos e dispositivos capazes de produzir, exibir e editar conteúdos multimídia fez surgir a necessidade de se adaptar, modificar e customizar diferentes tipos de mídia a diferentes necessidades do usuário. Nesse contexto, a área de Personalização e Adaptação de Conteúdo busca desenvolver soluções que atendam a tais necessidades. Sistemas de personalização, em geral, necessitam conhecer os dados presentes na mídia, surgindo, assim, a necessidade de uma indexação do conteúdo presente na mídia. No caso de vídeo digital, os esforços para a indexação automática utilizam como passo inicial a segmentação de vídeos em unidades de informação menores, como tomadas e cenas. A segmentação em cenas, em especial, é um desafio para pesquisadores graças a enorme variedade entre os vídeos e a própria ausência de um consenso na definição de cena. Diversas técnicas diferentes para a segmentação em cenas são reportadas na literatura. Uma técnica, em particular, destaca-se pelo baixo custo computacional: a técnica baseada em coerências visual. Utilizando-se operações de histogramas, a técnica objetiva-se a comparar tomadas adjacentes em busca de similaridades que poderiam indicar a presença de uma cena. Para melhorar os resultados obtidos, autores de trabalhos com tal enfoque utilizam-se de outras características, capazes de medir a \"quantidade de movimento\" das cenas, como os vetores de movimento. Assim, este trabalho apresenta uma técnica de segmentação de vídeo digital em tomadas e em cenas através da coerência visual e do fluxo óptico. Apresenta-se, ainda, uma série de avaliações de eficácia e de desempenho da técnica ao segmentar em tomadas e em cenas uma base de vídeo do domínio filmes / The popularization of applications and devices capable of producing, displaying and editing multimedia content did increase the need to adapt, modify and customize different types of media for different user needs. In this context, the area of Personalization and Content Adaptation seeks to develop solutions that meet these needs. Personalization systems, in general, need to know the data present in the media, thus needing for a media indexing process. In the case of digital video, the efforts for automatic indexing usually involves, as an initial step, to segment videos into smaller information units, such as shots and scenes. The scene segmentation, in particular, is a challenge to researchers due to the huge variety among the videos and the very absence of a consensus on the scene definition. Several scenes segmentation techniques are reported in the literature. One technique in particular stands out for its low computational cost: those techniques based on visual coherence. By using histograms, the technique compares adjacent shots to find similar shots which may indicate the presence of a scene. To improve the results, some related works uses other features to evaluate the motion dynamics of the scenes using features such as motion vectors. In this sense, this work presents a digital video segmentation technique for shots and scenes, using visual coherence and optical flow as its features. It also presents a series of evaluation in terms of effectiveness and performance of the technique when segmenting scenes and shots of a custom video database of the film domain

Made available in DSpace on 2016-04-26T18:11:41Z (GMT). No. of bitstreams: 1 Dissertacao Rogerio Largman Borovik.pdf: 8080670 bytes, checksum: 0601fcb659326615ae7929ca37a8a806 (MD5) Previous issue date: 2005-10-10 / Abstract The new conditions provided nowadays by technological advancements have made it possible to develop different ways of videographic production. While granting the concentration of different human activities within a single individual, the processes which are inherent to the digital universe have contributed as completely new tools to communication and collaborative productions. The concept of authorship is being questioned, both in the collective making and in the use of recyclable material, in such a way that a cultural substrate considered banal, every-day stuff and disposable can be transformed into raw material for artistic creation. The main objectives of this study were to present a historical overview of digital video, studying its communication process, enhanced by the arising of the Internet, and to analyze the possibilities inscribed in the audiovisual authoring software Keyworx, that is original both in its conceptual proposal and in its shape, interface and action. Keyworx is not a product manufactured by a company, but rather an educational project of the Waag Society, a Dutch research institution. This software makes a fusion of multi-user teleconference environment aspects with those of digital media process softwares (popularly known as VJ software ). A more profound discussion about the digital video interface and its functioning showed that it is of the utmost importance to a reflection on the particularities of a collaborative video creation model on the net. In this sense, the theories of Edmond Couchot, Lev Manovich, Arlindo Machado, Jay David Bolter, Richard Grusin and Giselle Beiguelman have occupied a key position in this study, because they elucidate aspects of the binary nature of digital media and their implications in the authoring processes, along with interviews with the creators of Keyworx. We could observe that, ever since the beginnings of digital video on the Internet, the communication roles between the sender and the receptor had their definition broadened, converted into interactors of a dialogical communication, which implies changes in the way they are created and distributed in the media. / As novas condições dadas pelos avanços tecnológicos na contemporaneidade propiciaram diferentes maneiras de produção videográfica. Ao mesmo tempo em que garante a concentração de diversas atividades humanas em um único indivíduo, os processos inerentes ao universo digital contribuíram como ferramentas inéditas para a comunicação e produções colaborativas. O conceito de autoria é questionado tanto no fazer conjunto como no uso de material reciclável , de maneira que um substrato cultural considerado banal, cotidiano e descartável, pode ser transformado em matéria prima para a criação artística. Esse estudo tem como objetivo principal apresentar um panorama histórico sobre o vídeo digital, estudando suas funções na comunicação on line; assim como analisar as possibilidades inscritas no software de autoração audiovisual Keyworx, que possui uma originalidade tanto em sua proposta conceitual, quanto em sua forma, interface e ação. O Keyworx não é um produto confeccionado por uma empresa, mas sim um projeto educacional da Waag Society, instituição de pesquisa holandesa. O software faz uma fusão de aspectos de ambientes de multi-usuário de tele-conferência, com os de software processuais de mídia digital (popularmente conhecidos como software de VJ ). Uma discussão mais profunda sobre a interface do vídeo digital e seu funcionamento, mostrou ser de suma importância para a reflexão sobre as particularidades de um modelo de criação colaborativa em vídeo na rede. Nesse sentido, as teorias de Edmond Couchot, Lev Manovich, Arlindo Machado, Jay David Bolter, Richard Grusin e Giselle Beiguelman encontraram lugar de destaque em nosso estudo, pois elucidaram aspectos da natureza binária da mídia digital e suas implicações nos processos de autoria; assim como a realização de entrevistas com os criadores do Keyworx. Pudemos verificar que, a partir do vídeo digital na Internet, os papéis comunicativos entre o emissor e o receptor têm sua definição alargada, convertidos em interatores de uma comunicação dialógica, o que implica em mudanças em sua forma de criação e distribuição midiática.

Made available in DSpace on 2016-04-29T14:23:12Z (GMT). No. of bitstreams: 1 Leonardo Belem de Souza.pdf: 9121191 bytes, checksum: ce21d3142b872987d62246b9cb003d92 (MD5) Previous issue date: 2012-09-29 / Nowadays, digital media are increasingly present throughout early childhood. The elementary schools coincide with the stage that children begin to develop their logical reasoning and cognitive aspects and brings the necessary conditions for the introduction of new technologies in learning even though there are difficulties to incorporate these methods in the teaching process. This research is based on theories and surveys that support the analysis of Khan Academy's case study (American NGO that has the mission to provide worldwide free education through digital videos available on the Internet). We are in a time that digital media are integrated, open content is available on the network such as videos, games and other digital publications are no longer restricted to only one device. Either by tablets, smartphones or personal computers, the effect of the popularization of broadband and wireless connection allows users to choose where, how and when to absorb certain content. Therefore, the contribution of this work is aligned to show teachers and students which digital media can become partners in learning with a focus on primary education. In the end, it draws an outline of the case study and investigations, presenting new paths for future lines of research that can be explored in depth / Atualmente, os meios digitais estão presentes cada vez mais cedo ao longo da infância. O ensino fundamental, por coincidir com a fase em que as crianças começam a desenvolver seu raciocínio lógico e cognitivo, traz aspectos e condições necessárias para a introdução de novas tecnologias na aprendizagem ainda que haja dificuldades na incorporação destes meios no ensino. Esta pesquisa está alicerçada em teorias e levantamentos que suportam a análise do estudo de caso da Khan Academy (ONG norte-americana que possui a missão de fornecer para o mundo inteiro educação gratuita através de vídeos digitais disponíveis na Internet). Estamos em um momento no qual os meios digitais se integram, conteúdos abertos disponíveis na rede como vídeos, jogos e outras publicações digitais não estão mais restritos somente a um dispositivo. Seja em tablets, smartphones ou computadores pessoais, o efeito da popularização da banda larga e conexão sem fio permite que os usuários escolham onde, como e quando querem consumir determinado conteúdo. Portanto, a contribuição deste trabalho se pauta em evidenciar aos professores e alunos quais meios digitais podem tornar-se parceiros na aprendizagem com foco no ensino fundamental e ao final traça um recorte entre o estudo de caso e as investigações realizadas, apresentando futuros caminhos para novas linhas de pesquisa que possam ser exploradas com mais profundidade

Providing computer-aided support for human analysis of videos has been a battle of extremes. Powerful solutions exist, but they tend to be domain-specific and complex. The user-friendly, simple systems provide little analysis support beyond basic media player functionality. We propose a human-centered, domain-independent solution between these two points. Our proposed model and system, VAST, is based on our experience in two diverse video analysis domains: science and athletics. Multiple-perspective location metadata is used to group related video clips together. Users interact with these clip groups through a novel interaction paradigm ? views. Each view provides a different context by which users can judge and evaluate the events that are captured by the video. Easy conversion between views allows the user to quickly switch between contexts. The model is designed to support a variety of user goals and expertise with minimal producer overhead. To evaluate our model, we developed a system prototype and conducted several rounds of user testing requiring the analysis of volleyball practice videos. The user tasks included: foreground analysis, ambiguous identification, background analysis, and planning. Both domain novices and experts participated in the study. User feedback, participant performance, and system logs were used to evaluate the system. VAST successfully supported a variety of problem solving strategies employed by participants during the course of the study. Participants had no difficulty handling multiple views (and resulting multiple video clips) simultaneously opened in the workspace. The capability to view multiple related clips at one time was highly regarded. In all tasks, except the open-ended portion of the background analysis, participants performed well. However, performance was not significantly influenced by domain expertise. Participants had a favorable opinion of the system?s intuitiveness, ease of use, enjoyability, and aesthetics. The majority of participants stated a desire to use VAST outside of the study, given the opportunity.

This research investigates scalable video communications and its applications to video streaming, conferencing and 3DTV. Scalable video coding (SVC) is a layer-based encoding scheme that provides spatial, temporal and quality scalability. Heterogeneity of the Internet and clients' operating environment necessitate the adaptation of media content to ensure a satisfactory multimedia experience. SVC's layer structure allows the extraction of partial bitstreams at reduced spatial, quality and temporal resolutions that adjust the media bitrate at a fine granularity to changes in network state. The main focus of this research work is in developing such extraction algorithms in the context of SVC. Based on a combination of metadata computations and prediction mechanisms, these algorithms evaluate the quality contribution of each layer in the SVC bitstream and make extraction decisions that are aimed at maximizing video quality while operating within the available bandwidth resources. These techniques are applied in two-way interaction and one-way streaming of 2D and 3D content. Depending on the delay tolerance of these applications, rate-distortion optimized extraction algorithms are proposed. For conferencing applications, the extraction decisions are made over single frames and frame pairs due to tight end-to-end delay constraints. The proposed extraction algorithms for 3D content streaming maximize the overall perceived 3D quality based on human stereoscopic perception. When compared to current extraction methods, the new algorithms offer better video quality at a given bitrate while performing lesser number of metadata computations in the post-encoding phase. The solutions proposed for each application achieve the recurring goal of maintaining the best possible level of end-user quality of multimedia experience in spite of network impairments.

This essay attempts to propose an art practice based on an ethical and aesthetic relation of author, subject, and viewer. This relationship is productive of results that are seen as critical to a precise, useful, and ethical representation of social problems. / text

This dissertation examines the process of using oral history and digital video to revise interpretation and represent more inclusive histories at three rural Texas historic sites—-Washington-on-the-Brazos State Historic Site, the Lyndon Baines Johnson State Park, and Varner-Hogg Plantation—-21st century sites that, to varying degrees, have persisted to interpret a Texas master narrative that is no longer socially tolerable in its silencing of marginalized Texas voices. In particular, the dissertation focuses on complicated and rarely discussed ethical issues that surfaced during my work from 2001 to 2006 shooting, editing, and situating interpretive documentary videos at the each of the three sites. Historic sites in Texas, like others across the United States and worldwide, have been receiving increasing pressure from scholars and community groups to represent women, racial minorities, and other marginalized groups more prominently in the narratives they interpret. Oral history and digital media have played key roles in this ongoing movement. Oral history has widely been touted as a tool to democratize history, and advocates of digital video interpretation cite its affordability, relative ease of use, and its ability to “say so much in so little time.” These factors are all the more compelling for local, regional, and state-wide historic sites that are chronically under-funded, under-staffed, and that must often interpret multiple, complicated narratives with very little time or space in which to present them. However, little has been done to explore the unique and complicated ethical issues that arise from using oral history and digital video at historic sites. This dissertation takes a case study approach and uses as its intellectual framework ideas of reflective practice, part of the contemporary discourse among public history practitioners. Each case study introduces the site through a critical analysis of the images and texts produced by the site; presents the central historical silence at each site; describes the solution that oral history and digital video interpretation was expected to provide; and then uses the project’s process-generated video footage and records to examine key situations that led me to raise ethical questions about the individual projects and the overall enterprise. / text

With the advance of the LCD technology, video quality is becoming increasingly important. In this thesis, we develop hardware-friendly low-complexity enhancement algorithms. Video quality enhancement methods can be classified into two main categories. Single frame methods are the first category. These methods have generally low computational complexity. Multi-frame methods combine information from more than one frame and require the motion information of objects in the scene to do so. We first concentrate on the contrast-enhancement problem by using both global (frame-wise) and local information derived from the image. We use the image histogram and present a regularization-based histogram modification method to avoid problems that are often created by histogram equalization. Next, we design a compression artifact reduction algorithm that reduces ringing artifacts, which is disturbing especially on large displays. Furthermore, to remove the blurriness in the original video we present a non-iterative diffusion-based sharpening algorithm, which enhances edges in a ringing-aware fashion. The diffusion-based technique works on gradient approximations in a neighborhood individually. This gives more freedom compared to modulating the high-pass filter output that is used to sharpen the edges. Motion estimation enables applications such as motion-compensated noise reduction, frame-rate conversion, de-interlacing, compression, and super-resolution. Motion estimation is an ill-posed problem and therefore requires the use of prior knowledge on motion of objects. Objects have inertia and are usually larger then pixels or a block of pixels in size, which creates spatio-temporal correlation. We design a method that uses temporal redundancy to improve motion-vector search by choosing bias vectors from the previous frame and adaptively penalizes deviations from the bias vectors. This increases the robustness of the motion-vector search. The spatial correlation is more reliable because temporal correlation is difficult to use when the objects move fast or accelerate in time, or have small sizes. Spatial smoothness is not valid across motion boundaries. We investigate using energy minimization for motion estimation and incorporate the spatial smoothness prior into the energy. By formulating the energy minimization iterations for each motion vector as the primal problem, we show that the dual problem is motion segmentation for that specific motion vector.

Image, sound, movement, interactivity, and collaborative work are fundamental tools in education because they support student’s cognitive development. Audiovisual systems such as digital video have made possible that students become less passive and much more active in the learning process by questioning the information they receive at school.According to Bartolome (1999), the digital video used to be considered a hobby more than a didactic tool. However, it has been proved that the use of video in education makes easier to accomplish the learning objectives. This important mean of communication and expression helps users –mainly young people- feel comfortable due to the development of ICT (Information and Communication Technologies) gives video widespread coverage on Internet. It is also important to mention that the use of ICT in education get its theoretical fundaments in constructivism, which makes imperative to keep an eye on its pedagogical uses. Learning trough the ICT (images, graphics, and audiovisual materials) require an audiovisual literacy implying the knowledge about ICT elements and making the addressee-addresser transition possible. It is well known that university students spend long hours in front of a computer, but it doesn’t mean they are taking advantage of this didactic tool.ObjectivesAs we know, the use of ICT characterizes our present social ties such as the attendance to schools. However, the use of ICT is not always adequate. Therefore, it is imperative to plan and put into practice a formative plan and special actions in order to educate people in the use of ICT so that they can consume and produce digital goods. For all these reasons, this study aims to:• Validate a formative model of audiovisual literacy with the support of digital video.• Obtain university student’s usage patterns on digital video in relation to content learning.MethodologyThis research had a pre-experimental design: pretest-intervention-post test with a single group. This methodology was chosen because it analyzes coincidental relations in groups already formed in a natural way. This design was administered in order to prove if the fundamental dimensions of audiovisual communication are shown in students coursing the subject “Nuevas Tecnologías”, and at the same time investigate the different ways digital video can favor their audiovisual literacy. / Imagen, sonido, movimiento, juego, trabajo en equipo son herramientas primordiales dentro de la educación, al ser elementos que proporcionan apoyo al desarrollo cognitivo. Los sistemas audiovisuales como el vídeo digital han permitido que el alumno deje de ser un agente receptor pasivo y pase a ser un actor dentro del proceso de aprendizaje cuestionando de esta forma la información que recibe en la escuela.Según Antonio Bartolomé (1999) el vídeo era considerado más un pasatiempo que una herramienta didáctica. Sin embargo se ha demostrado que su utilización en el campo educativo logra cumplir los fines y objetivos propuestos. Este potencial de expresión y comunicación hace que los usuarios --y principalmente los jóvenes-- se sientan muy confortados con éste medio, gracias al desarrollo de las tecnologías que han facilitado el uso y la difusión de materiales a través de Internet.Cabe destacar que esas nuevas formas de comunicación a través de los audiovisuales en el campo educativo sientan sus bases teóricas en el constructivismo, por tanto es elemental no perder de vista su forma de aplicación pedagógica. Estos modos de comunicación y estilos de aprendizaje requieren de una alfabetización audiovisual es decir el proceso de lectura de imágenes, gráficas, audiovisuales, implicando el aprendizaje de los elementos que los conforman y dando posibilidad de que el receptor se convierta en emisor. El hecho de que los estudiantes universitarios pasen el mayor número de sus horas de escuela frente al ordenador, no significa ni garantiza que estén aprovechando al máximo esta herramienta didáctica. El alumno, al estar frente al ordenador en sus ratos de ocio, disfruta viendo películas que puede bajar de Internet, así como de los vídeos de música, documentales y otros o de una conversación por el Messenger, Facebook sin embargo, deja de lado todo un potencial didáctico que podría emplear en el campo educativo, no sólo para su aprendizaje, sino también como medio para poder expresar sus ideas y emociones. Podría decirse que no se apropia de esa experiencia, ni se ha descubierto como creador y diseñador de su propio entorno de aprendizajes. De acuerdo a Moreira, A. (2002) actualmente se demanda a un sujeto alfabetizado audiovisualmente, toda vez que una persona analfabeta tecnológicamente queda al margen de la red comunicativa que ofertan los audiovisuales.FINES Y OBJETIVOSComo sabemos, el uso de la tecnología distingue a nuestros actuales vínculos sociales tales como la asistencia a las escuelas. Sin embargo, la utilización que se le da no siempre es la adecuada, de aquí se deriva la urgente necesidad de planificar y poner en práctica programas y acciones formativas destinadas a facilitar el acceso a las tecnologías digitales, para contribuir a formar una población alfabetizada en el uso de estas herramientas, que pueda producir y consumir bienes digitales. Para ello, se trabajaron los siguientes objetivos:• Validación de un modelo formativo de alfabetización audiovisual con apoyo del vídeo digital. • Extraer patrones de empleo del video digital de los estudiantes de nivel superior en relación al aprendizaje.METODOLOGÍA:La investigación se llevó a cabo empleando el diseño pre-experimental: pretest-tratamiento-postest con grupo único. Se opta por esta vía metodológica, porque analiza relaciones de causalidad partiendo de grupos ya conformados de manera natural. Este diseño se aplicó para comprobar si las dimensiones fundamentales de la comunicación audiovisual se manifiestan en los estudiantes matriculados en la asignatura de Nuevas Tecnologías y a su vez indagar hasta qué punto el vídeo digital puede favorecer la alfabetización audiovisual en los estudiantes. En cuanto a la muestra, por conveniencia, se ha empleado el Muestreo Accidental o Causal o por Accesibilidad, ya que el plan de estudios (MEIF) de la Licenciatura en Pedagogía permite trabajar con alumnos de los diversos semestres y áreas terminales.