769 resultados para video elements


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In recent years, the worldwide distribution of smartphone devices has been growing rapidly. Mobile technologies are evolving fast, a situation which provides new possibilities for mobile learning applications. Along with new delivery methods, this development enables new concepts for learning. This study focuses on the effectiveness and experience of a mobile learning video promoting the key features of a specific device. Through relevant learning theories, mobile technologies and empirical findings, the thesis presents the key elements for a mobile learning video that are essential for effective learning. This study also explores how previous experience with mobile services and knowledge of a mobile handset relate to final learning results. Moreover, this study discusses the optimal delivery mechanisms for a mobile video. The target group for the study consists of twenty employees of a Sanoma Company. The main findings show that the individual experience of learning and the actual learning results may differ and that the design for certain video elements, such as sound and the presentation of technical features, can have an impact on the experience and effectiveness of a mobile learning video. Moreover, a video delivery method based on cloud technologies and HTML5 is suggested to be used in parallel with standalone applications.

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The wide use of e-technologies represents a great opportunity for underserved segments of the population, especially with the aim of reintegrating excluded individuals back into society through education. This is particularly true for people with different types of disabilities who may have difficulties while attending traditional on-site learning programs that are typically based on printed learning resources. The creation and provision of accessible e-learning contents may therefore become a key factor in enabling people with different access needs to enjoy quality learning experiences and services. Another e-learning challenge is represented by m-learning (which stands for mobile learning), which is emerging as a consequence of mobile terminals diffusion and provides the opportunity to browse didactical materials everywhere, outside places that are traditionally devoted to education. Both such situations share the need to access materials in limited conditions and collide with the growing use of rich media in didactical contents, which are designed to be enjoyed without any restriction. Nowadays, Web-based teaching makes great use of multimedia technologies, ranging from Flash animations to prerecorded video-lectures. Rich media in e-learning can offer significant potential in enhancing the learning environment, through helping to increase access to education, enhance the learning experience and support multiple learning styles. Moreover, they can often be used to improve the structure of Web-based courses. These highly variegated and structured contents may significantly improve the quality and the effectiveness of educational activities for learners. For example, rich media contents allow us to describe complex concepts and process flows. Audio and video elements may be utilized to add a “human touch” to distance-learning courses. Finally, real lectures may be recorded and distributed to integrate or enrich on line materials. A confirmation of the advantages of these approaches can be seen in the exponential growth of video-lecture availability on the net, due to the ease of recording and delivering activities which take place in a traditional classroom. Furthermore, the wide use of assistive technologies for learners with disabilities injects new life into e-learning systems. E-learning allows distance and flexible educational activities, thus helping disabled learners to access resources which would otherwise present significant barriers for them. For instance, students with visual impairments have difficulties in reading traditional visual materials, deaf learners have trouble in following traditional (spoken) lectures, people with motion disabilities have problems in attending on-site programs. As already mentioned, the use of wireless technologies and pervasive computing may really enhance the educational learner experience by offering mobile e-learning services that can be accessed by handheld devices. This new paradigm of educational content distribution maximizes the benefits for learners since it enables users to overcome constraints imposed by the surrounding environment. While certainly helpful for users without disabilities, we believe that the use of newmobile technologies may also become a fundamental tool for impaired learners, since it frees them from sitting in front of a PC. In this way, educational activities can be enjoyed by all the users, without hindrance, thus increasing the social inclusion of non-typical learners. While the provision of fully accessible and portable video-lectures may be extremely useful for students, it is widely recognized that structuring and managing rich media contents for mobile learning services are complex and expensive tasks. Indeed, major difficulties originate from the basic need to provide a textual equivalent for each media resource composing a rich media Learning Object (LO). Moreover, tests need to be carried out to establish whether a given LO is fully accessible to all kinds of learners. Unfortunately, both these tasks are truly time-consuming processes, depending on the type of contents the teacher is writing and on the authoring tool he/she is using. Due to these difficulties, online LOs are often distributed as partially accessible or totally inaccessible content. Bearing this in mind, this thesis aims to discuss the key issues of a system we have developed to deliver accessible, customized or nomadic learning experiences to learners with different access needs and skills. To reduce the risk of excluding users with particular access capabilities, our system exploits Learning Objects (LOs) which are dynamically adapted and transcoded based on the specific needs of non-typical users and on the barriers that they can encounter in the environment. The basic idea is to dynamically adapt contents, by selecting them from a set of media resources packaged in SCORM-compliant LOs and stored in a self-adapting format. The system schedules and orchestrates a set of transcoding processes based on specific learner needs, so as to produce a customized LO that can be fully enjoyed by any (impaired or mobile) student.

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The main purpose of this study is to identify the elements of children's health games that have a positive impact on children’s health. The investigation is done by evaluating previous health game studies concentrating on children and five health affairs (such as asthma, cancer, diabetes, nutrition and obesity). In order to do so, firstly the topic of children’s health games is explained through its roots, as it is an interdisciplinary topic pertinent with many other fields. For this reason, the topics regarding the children’s health games as games, video games, children’s gameplay, and serious games along with health, relevant health affairs, and health promotion were covered. Secondly, the meta-study was conducted with the 56 articles on children’s health games. These 56 articles were analyzed with the coding technique defined by Charmaz’s Grounded Theory Method (Charmaz, 2006) for finding out which elements of children’s health games have a positive impact on children’s health promotion. The main result suggests that, although there are 24 different elements found and listed which all positive in their nature, their positive impact is a matter of how they are used or implemented through the consumption cycle of children’s health games and how all these elements interact with each other. In addition to this, a pragmatic proposal is formulated for possibly better or more successful health games. The study concludes with the declaration of the limitations encountered through the research and the recommendations for future research.

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The main purpose of this study is to identify the elements of children's health games that have a positive impact on children’s health. The investigation is done by evaluating previous health game studies concentrating on children and five health affairs (such as asthma, cancer, diabetes, nutrition and obesity). In order to do so, firstly the topic of children’s health games is explained through its roots, as it is an interdisciplinary topic pertinent with many other fields. For this reason, the topics regarding the children’s health games as games, video games, children’s gameplay, and serious games along with health, relevant health affairs, and health promotion were covered. Secondly, the meta-study was conducted with the 56 articles on children’s health games. These 56 articles were analyzed with the coding technique defined by Charmaz’s Grounded Theory Method (Charmaz, 2006) for finding out which elements of children’s health games have a positive impact on children’s health promotion. The main result suggests that, although there are 24 different elements found and listed which all positive in their nature, their positive impact is a matter of how they are used or implemented through the consumption cycle of children’s health games and how all these elements interact with each other. In addition to this, a pragmatic proposal is formulated for possibly better or more successful health games. The study concludes with the declaration of the limitations encountered through the research and the recommendations for future research.

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El video pretende hacer comprender que muchos de los materiales que utilizamos actualmente son, en parte, derivados del petróleo, obtenidos a partir de diferentes procesos químicos de síntesis. También se propone ver la importancia que tienen los productos en el medio ambiente.

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The present work presents a new method for activity extraction and reporting from video based on the aggregation of fuzzy relations. Trajectory clustering is first employed mainly to discover the points of entry and exit of mobiles appearing in the scene. In a second step, proximity relations between resulting clusters of detected mobiles and contextual elements from the scene are modeled employing fuzzy relations. These can then be aggregated employing typical soft-computing algebra. A clustering algorithm based on the transitive closure calculation of the fuzzy relations allows building the structure of the scene and characterises the ongoing different activities of the scene. Discovered activity zones can be reported as activity maps with different granularities thanks to the analysis of the transitive closure matrix. Taking advantage of the soft relation properties, activity zones and related activities can be labeled in a more human-like language. We present results obtained on real videos corresponding to apron monitoring in the Toulouse airport in France.

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Pós-graduação em Artes - IA

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Primary voice production occurs in the larynx through vibrational movements carried out by vocal folds. However, many problems can affect this complex system resulting in voice disorders. In this context, time-frequency-shape analysis based on embedding phase space plots and nonlinear dynamics methods have been used to evaluate the vocal fold dynamics during phonation. For this purpose, the present work used high-speed video to record the vocal fold movements of three subjects and extract the glottal area time series using an image segmentation algorithm. This signal is used for an optimization method which combines genetic algorithms and a quasi-Newton method to optimize the parameters of a biomechanical model of vocal folds based on lumped elements (masses, springs and dampers). After optimization, this model is capable of simulating the dynamics of recorded vocal folds and their glottal pulse. Bifurcation diagrams and phase space analysis were used to evaluate the behavior of this deterministic system in different circumstances. The results showed that this methodology can be used to extract some physiological parameters of vocal folds and reproduce some complex behaviors of these structures contributing to the scientific and clinical evaluation of voice production. (C) 2010 Elsevier Inc. All rights reserved.

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Students are now involved in a vastly different textual landscape than many English scholars, one that relies on the “reading” and interpretation of multiple channels of simultaneous information. As a response to these new kinds of literate practices, my dissertation adds to the growing body of research on multimodal literacies, narratology in new media, and rhetoric through an examination of the place of video games in English teaching and research. I describe in this dissertation a hybridized theoretical basis for incorporating video games in English classrooms. This framework for textual analysis includes elements from narrative theory in literary study, rhetorical theory, and literacy theory, and when combined to account for the multiple modalities and complexities of gaming, can provide new insights about those theories and practices across all kinds of media, whether in written texts, films, or video games. In creating this framework, I hope to encourage students to view texts from a meta-level perspective, encompassing textual construction, use, and interpretation. In order to foster meta-level learning in an English course, I use specific theoretical frameworks from the fields of literary studies, narratology, film theory, aural theory, reader-response criticism, game studies, and multiliteracies theory to analyze a particular video game: World of Goo. These theoretical frameworks inform pedagogical practices used in the classroom for textual analysis of multiple media. Examining a video game from these perspectives, I use analytical methods from each, including close reading, explication, textual analysis, and individual elements of multiliteracies theory and pedagogy. In undertaking an in-depth analysis of World of Goo, I demonstrate the possibilities for classroom instruction with a complex blend of theories and pedagogies in English courses. This blend of theories and practices is meant to foster literacy learning across media, helping students develop metaknowledge of their own literate practices in multiple modes. Finally, I outline a design for a multiliteracies course that would allow English scholars to use video games along with other texts to interrogate texts as systems of information. In doing so, students can hopefully view and transform systems in their own lives as audiences, citizens, and workers.

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Esta tesis presenta un novedoso marco de referencia para el análisis y optimización del retardo de codificación y descodificación para vídeo multivista. El objetivo de este marco de referencia es proporcionar una metodología sistemática para el análisis del retardo en codificadores y descodificadores multivista y herramientas útiles en el diseño de codificadores/descodificadores para aplicaciones con requisitos de bajo retardo. El marco de referencia propuesto caracteriza primero los elementos que tienen influencia en el comportamiento del retardo: i) la estructura de predicción multivista, ii) el modelo hardware del codificador/descodificador y iii) los tiempos de proceso de cuadro. En segundo lugar, proporciona algoritmos para el cálculo del retardo de codificación/ descodificación de cualquier estructura arbitraria de predicción multivista. El núcleo de este marco de referencia consiste en una metodología para el análisis del retardo de codificación/descodificación multivista que es independiente de la arquitectura hardware del codificador/descodificador, completada con un conjunto de modelos que particularizan este análisis del retardo con las características de la arquitectura hardware del codificador/descodificador. Entre estos modelos, aquellos basados en teoría de grafos adquieren especial relevancia debido a su capacidad de desacoplar la influencia de los diferentes elementos en el comportamiento del retardo en el codificador/ descodificador, mediante una abstracción de su capacidad de proceso. Para revelar las posibles aplicaciones de este marco de referencia, esta tesis presenta algunos ejemplos de su utilización en problemas de diseño que afectan a codificadores y descodificadores multivista. Este escenario de aplicación cubre los siguientes casos: estrategias para el diseño de estructuras de predicción que tengan en consideración requisitos de retardo además del comportamiento tasa-distorsión; diseño del número de procesadores y análisis de los requisitos de velocidad de proceso en codificadores/ descodificadores multivista dado un retardo objetivo; y el análisis comparativo del comportamiento del retardo en codificadores multivista con diferentes capacidades de proceso e implementaciones hardware. ABSTRACT This thesis presents a novel framework for the analysis and optimization of the encoding and decoding delay for multiview video. The objective of this framework is to provide a systematic methodology for the analysis of the delay in multiview encoders and decoders and useful tools in the design of multiview encoders/decoders for applications with low delay requirements. The proposed framework characterizes firstly the elements that have an influence in the delay performance: i) the multiview prediction structure ii) the hardware model of the encoder/decoder and iii) frame processing times. Secondly, it provides algorithms for the computation of the encoding/decoding delay of any arbitrary multiview prediction structure. The core of this framework consists in a methodology for the analysis of the multiview encoding/decoding delay that is independent of the hardware architecture of the encoder/decoder, which is completed with a set of models that particularize this delay analysis with the characteristics of the hardware architecture of the encoder/decoder. Among these models, the ones based in graph theory acquire special relevance due to their capacity to detach the influence of the different elements in the delay performance of the encoder/decoder, by means of an abstraction of its processing capacity. To reveal possible applications of this framework, this thesis presents some examples of its utilization in design problems that affect multiview encoders and decoders. This application scenario covers the following cases: strategies for the design of prediction structures that take into consideration delay requirements in addition to the rate-distortion performance; design of number of processors and analysis of processor speed requirements in multiview encoders/decoders given a target delay; and comparative analysis of the encoding delay performance of multiview encoders with different processing capabilities and hardware implementations.

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We present a novel framework for the analysis and optimization of encoding latency for multiview video. Firstly, we characterize the elements that have an influence in the encoding latency performance: (i) the multiview prediction structure and (ii) the hardware encoder model. Then, we provide algorithms to find the encoding latency of any arbitrary multiview prediction structure. The proposed framework relies on the directed acyclic graph encoder latency (DAGEL) model, which provides an abstraction of the processing capacity of the encoder by considering an unbounded number of processors. Using graph theoretic algorithms, the DAGEL model allows us to compute the encoding latency of a given prediction structure, and determine the contribution of the prediction dependencies to it. As an example of DAGEL application, we propose an algorithm to reduce the encoding latency of a given multiview prediction structure up to a target value. In our approach, a minimum number of frame dependencies are pruned, until the latency target value is achieved, thus minimizing the degradation of the rate-distortion performance due to the removal of the prediction dependencies. Finally, we analyze the latency performance of the DAGEL derived prediction structures in multiview encoders with limited processing capacity.

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Esta tesis presenta un estudio exhaustivo sobre la evaluación de la calidad de experiencia (QoE, del inglés Quality of Experience) percibida por los usuarios de sistemas de vídeo 3D, analizando el impacto de los efectos introducidos por todos los elementos de la cadena de procesamiento de vídeo 3D. Por lo tanto, se presentan varias pruebas de evaluación subjetiva específicamente diseñadas para evaluar los sistemas considerados, teniendo en cuenta todos los factores perceptuales relacionados con la experiencia visual tridimensional, tales como la percepción de profundidad y la molestia visual. Concretamente, se describe un test subjetivo basado en la evaluación de degradaciones típicas que pueden aparecer en el proceso de creación de contenidos de vídeo 3D, por ejemplo debidas a calibraciones incorrectas de las cámaras o a algoritmos de procesamiento de la señal de vídeo (p. ej., conversión de 2D a 3D). Además, se presenta el proceso de generación de una base de datos de vídeos estereoscópicos de alta calidad, disponible gratuitamente para la comunidad investigadora y que ha sido utilizada ampliamente en diferentes trabajos relacionados con vídeo 3D. Asimismo, se presenta otro estudio subjetivo, realizado entre varios laboratorios, con el que se analiza el impacto de degradaciones causadas por la codificación de vídeo, así como diversos formatos de representación de vídeo 3D. Igualmente, se describen tres pruebas subjetivas centradas en el estudio de posibles efectos causados por la transmisión de vídeo 3D a través de redes de televisión sobre IP (IPTV, del inglés Internet Protocol Television) y de sistemas de streaming adaptativo de vídeo. Para estos casos, se ha propuesto una innovadora metodología de evaluación subjetiva de calidad vídeo, denominada Content-Immersive Evaluation of Transmission Impairments (CIETI), diseñada específicamente para evaluar eventos de transmisión simulando condiciones realistas de visualización de vídeo en ámbitos domésticos, con el fin de obtener conclusiones más representativas sobre la experiencia visual de los usuarios finales. Finalmente, se exponen dos experimentos subjetivos comparando varias tecnologías actuales de televisores 3D disponibles en el mercado de consumo y evaluando factores perceptuales de sistemas Super Multiview Video (SMV), previstos a ser la tecnología futura de televisores 3D de consumo, gracias a una prometedora visualización de contenido 3D sin necesidad de gafas específicas. El trabajo presentado en esta tesis ha permitido entender los factores perceptuales y técnicos relacionados con el procesamiento y visualización de contenidos de vídeo 3D, que pueden ser de utilidad en el desarrollo de nuevas tecnologías y técnicas de evaluación de la QoE, tanto metodologías subjetivas como métricas objetivas. ABSTRACT This thesis presents a comprehensive study of the evaluation of the Quality of Experience (QoE) perceived by the users of 3D video systems, analyzing the impact of effects introduced by all the elements of the 3D video processing chain. Therefore, various subjective assessment tests are presented, particularly designed to evaluate the systems under consideration, and taking into account all the perceptual factors related to the 3D visual experience, such as depth perception and visual discomfort. In particular, a subjective test is presented, based on evaluating typical degradations that may appear during the content creation, for instance due to incorrect camera calibration or video processing algorithms (e.g., 2D to 3D conversion). Moreover, the process of generation of a high-quality dataset of 3D stereoscopic videos is described, which is freely available for the research community, and has been already widely used in different works related with 3D video. In addition, another inter-laboratory subjective study is presented analyzing the impact of coding impairments and representation formats of stereoscopic video. Also, three subjective tests are presented studying the effects of transmission events that take place in Internet Protocol Television (IPTV) networks and adaptive streaming scenarios for 3D video. For these cases, a novel subjective evaluation methodology, called Content-Immersive Evaluation of Transmission Impairments (CIETI), was proposed, which was especially designed to evaluate transmission events simulating realistic home-viewing conditions, to obtain more representative conclusions about the visual experience of the end users. Finally, two subjective experiments are exposed comparing various current 3D displays available in the consumer market, and evaluating perceptual factors of Super Multiview Video (SMV) systems, expected to be the future technology for consumer 3D displays thanks to a promising visualization of 3D content without specific glasses. The work presented in this thesis has allowed to understand perceptual and technical factors related to the processing and visualization of 3D video content, which may be useful in the development of new technologies and approaches for QoE evaluation, both subjective methodologies and objective metrics.

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Thesis (Master's)--University of Washington, 2016-06

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Video streaming via Transmission Control Protocol (TCP) networks has become a popular and highly demanded service, but its quality assessment in both objective and subjective terms has not been properly addressed. In this paper, based on statistical analysis a full analytic model of a no-reference objective metric, namely pause intensity (PI), for video quality assessment is presented. The model characterizes the video playout buffer behavior in connection with the network performance (throughput) and the video playout rate. This allows for instant quality measurement and control without requiring a reference video. PI specifically addresses the need for assessing the quality issue in terms of the continuity in the playout of TCP streaming videos, which cannot be properly measured by other objective metrics such as peak signal-to-noise-ratio, structural similarity, and buffer underrun or pause frequency. The performance of the analytical model is rigidly verified by simulation results and subjective tests using a range of video clips. It is demonstrated that PI is closely correlated with viewers' opinion scores regardless of the vastly different composition of individual elements, such as pause duration and pause frequency which jointly constitute this new quality metric. It is also shown that the correlation performance of PI is consistent and content independent. © 2013 IEEE.

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Cancer is a multistep process that begins with the transformation of normal epithelial cells and continues with tumor growth, stromal invasion and metastasis. The remodeling of the peritumoral environment is decisive for the onset of tumor invasiveness. This event is dependent on epithelial-stromal interactions, degradation of extracellular matrix components and reorganization of fibrillar components. Our research group has studied in a new proposed rodent model the participation of cellular and molecular components in the prostate microenvironment that contributes to cancer progression. Our group adopted the gerbil Meriones unguiculatus as an alternative experimental model for prostate cancer study. This model has presented significant responses to hormonal treatments and to development of spontaneous and induced neoplasias. The data obtained indicate reorganization of type I collagen fibers and reticular fibers, synthesis of new components such as tenascin and proteoglycans, degradation of basement membrane components and elastic fibers and increased expression of metalloproteinases. Fibroblasts that border the region, apparently participate in the stromal reaction. The roles of each of these events, as well as some signaling molecules, participants of neoplastic progression and factors that promote genetic reprogramming during epithelial-stromal transition are also discussed.