Um dos obstáculos para o uso disseminado do multicast na Internet global é o desenvolvimento de protocolos de controle de congestionamento adequados. Um fator que contribui para este problema é a heterogeneidade de equipamentos, enlaces e condições de acesso dos receptores, a qual aumenta a complexidade de implementação e validação destes protocolos. Devido ao multicast poder envolver milhares de receptores simultaneamente, o desafio deste tipo de protocolo se torna ainda maior, pois além das questões relacionadas ao congestionamento da rede, é necessário considerar fatores como sincronismo, controle de feedbacks, equidade de tráfego, entre outros. Por esses motivos, os protocolos de controle de congestionamento multicast têm sido um tópico de intensa pesquisa nos últimos anos. Uma das alternativas para o controle de congestionamento multicast na Internet é o protocolo ALMTF (Adaptive Layered Multicast TCP-Friendly), o qual faz parte do projeto SAM (Sistema Adaptativo Multimídia). Uma vantagem desse algoritmo é inferir o nível de congestionamento da rede, determinando a taxa de recebimento mais apropriada para cada receptor. Além disso, ele realiza o controle da banda recebida, visando à justiça e a imparcialidade com os demais tráfegos concorrentes. O ALMTF foi desenvolvido originalmente em uma Tese de doutorado e teve a sua validação no simulador de redes NS-2 (Network Simulator). Este trabalho tem como objetivo estender o protocolo para uma rede real, implementando, validando os seus mecanismos e propondo novas alternativas que o adaptem para esse ambiente. Além disso, efetuar a comparação dos resultados reais com a simulação, identificando as diferenças e promovendo as pesquisas experimentais na área. / One of the obstacles for the widespread use of the multicast in the global Internet is the development of adequate protocols for congestion control. One factor that contributes for this problem is the heterogeneity of equipments, enlaces and conditions of access of the receivers, which increases the implementation and validation complexity of these protocols. Due to the number (thousands) of receivers simultaneously involved in multicast, the challenge of these protocols is even higher. Besides the issues related to the network congestion, it is necessary to consider factors such as synchronism, feedback control, fairness, among others. For these reasons, the multicast congestion control protocols have been a topic of intense research in recent years. The ALMTF protocol (Adaptive Layered Multicast TCP-Friendly), which is part of project SAM, is one of the alternatives for the multicast congestion control in the Internet. One advantage of this algorithm is its ability to infer the network congestion level, assigning the best receiving rate for each receptor. Besides that, the protocol manages the received rate, aiming to achieve fairness and impartiality with the competing network traffic. The ALMTF was developed originally in a Ph.D. Thesis and had its validation under NS-2 simulator. The goal this work is to extend the protocol ALMTF for a real network, validating its mechanisms and considering new alternatives to adapt it for this environment. Moreover, to make the comparison of the real results with the simulation, being identified the differences and promoting the experimental research in the area.

abstract: As the application of interactive media systems expands to address broader problems in health, education and creative practice, they fall within a higher dimensional space for which it is inherently more complex to design. In response to this need an emerging area of interactive system design, referred to as experiential media systems, applies hybrid knowledge synthesized across multiple disciplines to address challenges relevant to daily experience. Interactive neurorehabilitation (INR) aims to enhance functional movement therapy by integrating detailed motion capture with interactive feedback in a manner that facilitates engagement and sensorimotor learning for those who have suffered neurologic injury. While INR shows great promise to advance the current state of therapies, a cohesive media design methodology for INR is missing due to the present lack of substantial evidence within the field. Using an experiential media based approach to draw knowledge from external disciplines, this dissertation proposes a compositional framework for authoring visual media for INR systems across contexts and applications within upper extremity stroke rehabilitation. The compositional framework is applied across systems for supervised training, unsupervised training, and assisted reflection, which reflect the collective work of the Adaptive Mixed Reality Rehabilitation (AMRR) Team at Arizona State University, of which the author is a member. Formal structures and a methodology for applying them are described in detail for the visual media environments designed by the author. Data collected from studies conducted by the AMRR team to evaluate these systems in both supervised and unsupervised training contexts is also discussed in terms of the extent to which the application of the compositional framework is supported and which aspects require further investigation. The potential broader implications of the proposed compositional framework and methodology are the dissemination of interdisciplinary information to accelerate the informed development of INR applications and to demonstrate the potential benefit of generalizing integrative approaches, merging arts and science based knowledge, for other complex problems related to embodied learning. / Dissertation/Thesis / This video shows a demonstration of the home-based AMRR system in use with a stroke survivor. Participant is shown receiving instructions, followed by performance of one interactive Level 1 set of reaching to grasp and lift a portable cylinder. / This video shows a demonstration of the home-based AMRR system in use with a stroke survivor. Participant is shown performing an interactive Level 1 set of reaching to touch a flat object. / This video shows a demonstration of the home-based AMRR system in use with a stroke survivor. Participant is shown performing an interactive Level 2 set of reaching to grasp a cone. / This video shows a demonstration of the home-based AMRR system in use with a stroke survivor. Participant is shown performing an interactive Level 3 set of reaching to grasp and transport the cylinder between two locations. / This video shows a demonstration of the home-based AMRR system in use with a stroke survivor. Participant is shown setting up the targets used for training. / This video shows the clinical AMRR feedback for trajectory performance and speed. Video depicts the image formation and plays the musical phrase generated by a reach that is (1) efficient, (2) with horizontal trajectory deviation, (3) and slow. / This video shows the clinical AMRR feedback for joint function and compensation. Video depicts (1) image rotation for wrist rotation, (2) the orchestral sound for elbow extension, (3) the shoulder compensation sound and (4) the torso compensation sound. / This video shows the clinical AMRR feedback demonstrating different aspects of joint correlation. Video depicts (1) an efficient reach with elbow extension and (2) inefficient reach with shoulder compensation sound. / This video shows the home-based AMRR Level 1 visual feedback for negative vertical trajectory error. Rocks are depicted to have sunken underwater. / This video shows the home-based AMRR Level 1 visual feedback for a successful lift with an efficient reaching path. The clearance of the fog indicates the portable object was lifted beyond a height threshold. / This video shows the home-based AMRR Level 2 visual feedback for overall path and grasp performance. Video depicts feedback for the following types of overall performance: efficient path, curvature, segmentation, and grasp completion. / This video shows the home-based AMRR Level 3 audiovisual feedback for overall efficiency of a sequence task. Video depicts (1) efficient performance, (2) slightly inefficient performance, and (3) severely inefficient performance. / This video shows the home-based AMRR Level 3 audiovisual feedback for overall efficiency of a transport task. Video depicts (1) efficient performance, (2) slightly inefficient performance, and (3) severely inefficient performance. / This video shows a demonstration of the clinical AMRR system in use with a stroke survivor and supervising therapist. Participant is shown performing interactive reaches to a cone. / Doctoral Dissertation Media Arts and Sciences 2014

abstract: Multimedia educational technologies have increased their presence in traditional and online classrooms over the course of the previous decade. These tools hold value and can promote positive learning outcomes but are reliant on students’ degree of cognitive engagement and self-regulation. When students are not cognitively engaged or have low self-regulation capabilities, their interaction with the technology becomes less impactful because of decreased learning outcomes. Building or altering technologies to cognitively engage students is costly and timely; the present study investigates if introducing higher agency roles, to change the role of the student, increases learning outcomes. Specifically, this study investigates if higher agency roles of a designer or teacher enhances cognitive engagement and improves learning when compared to the conventional role of a learner. Improved learning outcomes were observed from the pretest to posttest for the learner, designer, and teacher role. Participants engaged with higher agency roles did not demonstrate more growth from pretest to posttest when compared to the control group, but participants in the teacher role outperformed those in the designer role. Additionally, reading ability did not impact learning gains across groups. While students who engaged with higher agency roles did not achieve greater learning outcomes than students in the control group, results indicate a learning effect across groups. Results of this study suggest that it was underpowered. Further research is needed to determine the extent of the impact that higher agency roles have on learning outcomes. / Dissertation/Thesis / Masters Thesis Human Systems Engineering 2018

Made available in DSpace on 2014-06-11T19:22:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-31Bitstream added on 2014-06-13T19:06:24Z : No. of bitstreams: 1 santos_fp_me_prud.pdf: 2718206 bytes, checksum: 7aec825622eb74efed5b29f33c15bbe9 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O uso de mapas, Atlas e mais recentemente, imagens de sensoriamento remoto constituem uma importante parte do currículo escolar, particularmente na disciplina de Geografia. Os Parâmetros Curriculares Nacionais, documento que apresenta as linhas norteadoras do ensino fundamental no Brasil, enfatizam a importância da tecnologia na educação ao propor o uso de recursos multimídia para auxiliar no aprendizado de conceitos de representação e espacialização. Através de recursos multimídia surge a capacidade de manipular representações mapeadas nos Atlas, possibilitando a seleção e modificação de informações, o que os tornam mais atrativos e didáticos. Este trabalho tem por objetivo apresentar o desenvolvimento de um protótipo de Atlas Escolar Interativo para alunos do quarto ciclo do ensino fundamental com uso de ferramentas multimídia. O projeto do Atlas constituiu de duas grandes etapas. A primeira denominada projeto cartográfico, a qual consiste na análise da demanda do usuário e definição do conteúdo, projeto de composição geral e projeto gráfico e da interface. A segunda etapa é a produção do Atlas que engloba a aquisição e edição da base de dados geográficos... / The use of maps, atlas and images of remote sensing constitute an important part of the school curriculum, particularly in the discipline of Geography. The National Curriculum, which presents the contents guidelines that is taught in Brazil schools, emphasize the importance of the technology in the education, by proposing the use of multimedia resource to aid in the learning process of geographical concepts. Through resources multimedia is possible to manipulate and interact with maps, what turns them more attractive and instigating. This paper presents the development of a prototype of Interactive School Atlas for students of the fourth cycle of the elementary school. The project was constituted of two great stages. The first one was denominated as cartographic project. The second stage was the production of the Atlas. that includes the acquisition and edition of the geographical ... (Complete abstract click electronic access below)

abstract: The current study investigated the task of coloring static images with multimedia learning to determine the impact on retention and transfer scores. After watching a multimedia video on the formation of lightning participants were assigned to either a passive, active, or constructive condition based on the ICAP Framework. Participants colored static images on key concepts from the video, passive condition observed the images, active condition colored the images by applying the concepts, and the constructive condition colored the images by generating new ideas and concepts. The study did not support the hypothesis that the constructive condition would have increased retention and transfer scores over the active and passive conditions. The mental effort measures did not show significance among groups in relation to learning but perception measures did show an increase in participants enjoyment and engagement. Since the coloring craze has become more accepted for adults then could coloring be a way to increase participants learning through engagement. / Dissertation/Thesis / Masters Thesis Human Systems Engineering 2018

abstract: Today's mobile devices have to support computation-intensive multimedia applications with a limited energy budget. In this dissertation, we present architecture level and algorithm-level techniques that reduce energy consumption of these devices with minimal impact on system quality. First, we present novel techniques to mitigate the effects of SRAM memory failures in JPEG2000 implementations operating in scaled voltages. We investigate error control coding schemes and propose an unequal error protection scheme tailored for JPEG2000 that reduces overhead without affecting the performance. Furthermore, we propose algorithm-specific techniques for error compensation that exploit the fact that in JPEG2000 the discrete wavelet transform outputs have larger values for low frequency subband coefficients and smaller values for high frequency subband coefficients. Next, we present use of voltage overscaling to reduce the data-path power consumption of JPEG codecs. We propose an algorithm-specific technique which exploits the characteristics of the quantized coefficients after zig-zag scan to mitigate errors introduced by aggressive voltage scaling. Third, we investigate the effect of reducing dynamic range for datapath energy reduction. We analyze the effect of truncation error and propose a scheme that estimates the mean value of the truncation error during the pre-computation stage and compensates for this error. Such a scheme is very effective for reducing the noise power in applications that are dominated by additions and multiplications such as FIR filter and transform computation. We also present a novel sum of absolute difference (SAD) scheme that is based on most significant bit truncation. The proposed scheme exploits the fact that most of the absolute difference (AD) calculations result in small values, and most of the large AD values do not contribute to the SAD values of the blocks that are selected. Such a scheme is highly effective in reducing the energy consumption of motion estimation and intra-prediction kernels in video codecs. Finally, we present several hybrid energy-saving techniques based on combination of voltage scaling, computation reduction and dynamic range reduction that further reduce the energy consumption while keeping the performance degradation very low. For instance, a combination of computation reduction and dynamic range reduction for Discrete Cosine Transform shows on average, 33% to 46% reduction in energy consumption while incurring only 0.5dB to 1.5dB loss in PSNR. / Dissertation/Thesis / Ph.D. Electrical Engineering 2012

abstract: The gameplay experience can be understood as an interaction between player and game design characteristics. A greater understanding of these characteristics can be gained through empirical means. Subsequently, an enhanced knowledge of these characteristics should enable the creation of games that effectively generate desirable experiences for players. The purpose of this study was to investigate the relationships between gameplay enjoyment and the individual characteristics of gaming goal orientations, game usage, and gender. A total of 301 participants were surveyed and the data were analyzed using Structural Equation Modeling (SEM). This led to an expanded Gameplay Enjoyment Model (GEM) with 41 game features, an overarching Enjoyment factor, and 9 specific components, including Challenge, Companionship, Discovery, Fantasy, Fidelity, Identity, Multiplayer, Recognition, and Strategy. Furthermore, the 3x2 educational goal orientation framework was successfully applied to a gaming context. The resulting 3x2 Gaming Goal Orientations (GGO) model consists of 18 statements that describe players' motivations for gaming, which are distributed across the six dimensions of Task-Approach, Task-Avoidance, Self-Approach, Self-Avoidance, Other-Approach, and Other-Avoidance. Lastly, players' individual characteristics were used to predict gameplay enjoyment, which resulted in the formation of the GEM-Individual Characteristics (GEM-IC) model. In GEM-IC, the six GGO dimensions were the strongest predictors. Meanwhile, game usage variables like multiplayer, genre, and platform preference, were minimal to moderate predictors. Although commonly appearing in games research, gender and game time commitment variables failed to predict enjoyment. The results of this study enable important work to be conducted involving game experiences and player characteristics. After several empirical iterations, GEM is considered suitable to employ as a research and design tool. In addition, GGO should be useful to researchers interested in how player motivations relate to gameplay experiences. Moreover, GEM-IC points to several variables that may prove useful in future research. Accordingly, it is posited that researchers will derive more meaningful insights on games and players by investigating detailed, context-specific characteristics as compared to general, demographic ones. Ultimately, it is believed that GEM, GGO, and GEM-IC will be useful tools for researchers and designers who seek to create effective gameplay experiences that meet the needs of players. / Dissertation/Thesis / Ph.D. Educational Technology 2013

abstract: CYOA is a prototype of an iPhone application that produces a single, generative, musical work. This document details some of the thoughts and practices that informed its design, and specifically addresses the overlap between application structure and musical form. The concept of composed instruments is introduced and briefly discussed, some features of video game design that relate to this project are considered, and some specifics of hardware implementation are addressed. / Dissertation/Thesis / D.M.A. Composition 2013

abstract: The rapid escalation of technology and the widespread emergence of modern technological equipments have resulted in the generation of humongous amounts of digital data (in the form of images, videos and text). This has expanded the possibility of solving real world problems using computational learning frameworks. However, while gathering a large amount of data is cheap and easy, annotating them with class labels is an expensive process in terms of time, labor and human expertise. This has paved the way for research in the field of active learning. Such algorithms automatically select the salient and exemplar instances from large quantities of unlabeled data and are effective in reducing human labeling effort in inducing classification models. To utilize the possible presence of multiple labeling agents, there have been attempts towards a batch mode form of active learning, where a batch of data instances is selected simultaneously for manual annotation. This dissertation is aimed at the development of novel batch mode active learning algorithms to reduce manual effort in training classification models in real world multimedia pattern recognition applications. Four major contributions are proposed in this work: $(i)$ a framework for dynamic batch mode active learning, where the batch size and the specific data instances to be queried are selected adaptively through a single formulation, based on the complexity of the data stream in question, $(ii)$ a batch mode active learning strategy for fuzzy label classification problems, where there is an inherent imprecision and vagueness in the class label definitions, $(iii)$ batch mode active learning algorithms based on convex relaxations of an NP-hard integer quadratic programming (IQP) problem, with guaranteed bounds on the solution quality and $(iv)$ an active matrix completion algorithm and its application to solve several variants of the active learning problem (transductive active learning, multi-label active learning, active feature acquisition and active learning for regression). These contributions are validated on the face recognition and facial expression recognition problems (which are commonly encountered in real world applications like robotics, security and assistive technology for the blind and the visually impaired) and also on collaborative filtering applications like movie recommendation. / Dissertation/Thesis / Ph.D. Computer Science 2013

abstract: Achievement of many long-term goals requires sustained practice over long durations. Examples include goals related to areas of high personal and societal benefit, such as physical fitness, which requires a practice of frequent exercise; self-education, which requires a practice of frequent study; or personal productivity, which requires a practice of performing work. Maintaining these practices can be difficult, because even though obvious benefits come with achieving these goals, an individual's willpower may not always be sufficient to sustain the required effort. This dissertation advocates addressing this problem by designing novel interfaces that provide people with new practices that are fun and enjoyable, thereby reducing the need for users to draw upon willpower when pursuing these long-term goals. To draw volitional usage, these practice-oriented interfaces can integrate key characteristics of existing activities, such as music-making and other hobbies, that are already known to draw voluntary participation over long durations. This dissertation makes several key contributions to provide designers with the necessary tools to create practice-oriented interfaces. First, it consolidates and synthesizes key ideas from fields such as activity theory, self-determination theory, HCI design, and serious leisure. It also provides a new conceptual framework consisting of heuristics for designing systems that draw new users, plus heuristics for making systems that will continue drawing usage from existing users over time. These heuristics serve as a collection of useful ideas to consider when analyzing or designing systems, and this dissertation postulates that if designers build these characteristics into their products, the resulting systems will draw more volitional usage. To demonstrate the framework's usefulness as an analytical tool, it is applied as a set of analytical lenses upon three previously-existing experiential media systems. To demonstrate its usefulness as a design tool, the framework is used as a guide in the development of an experiential media system called pdMusic. This system is installed at public events for user studies, and the study results provide qualitative support for many framework heuristics. Lastly, this dissertation makes recommendations to scholars and designers on potential future ways to examine the topic of volitional usage. / Dissertation/Thesis / Ph.D. Media Arts and Sciences 2013