Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-06-18T14:20:29Z No. of bitstreams: 1 Dissertação- Jhonathan Araújo Oliveira.pdf: 17407325 bytes, checksum: 9ed1cb282822c8dd666684f5cc5e0219 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-19T21:10:55Z (GMT) No. of bitstreams: 1 Dissertação- Jhonathan Araújo Oliveira.pdf: 17407325 bytes, checksum: 9ed1cb282822c8dd666684f5cc5e0219 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-19T21:12:04Z (GMT) No. of bitstreams: 1 Dissertação- Jhonathan Araújo Oliveira.pdf: 17407325 bytes, checksum: 9ed1cb282822c8dd666684f5cc5e0219 (MD5) / Made available in DSpace on 2015-06-19T21:12:04Z (GMT). No. of bitstreams: 1 Dissertação- Jhonathan Araújo Oliveira.pdf: 17407325 bytes, checksum: 9ed1cb282822c8dd666684f5cc5e0219 (MD5) Previous issue date: 2013-09-24 / Scalability and high demand for resources are the main challenges that content providers face in multimedia applications based on networks. For instance, YouTube is one of the most popular delivery systems video on demand, the users send 100 hours of video every minute to its servers and more than four billion hours of video are watched every month. The CDN-P2P systems is widely recognized as a scalable alternative for multimedia content delivery in the Internet. In these systems, the peers from a peerto- peer network (P2P) share their resources thus reducing the demands on the network infrastructure for content delivery (CDN). Moreover, the CDN server to guarantee the availability of content when the peers contributions are limited by the churn, or when the content is is unprecedented to the peers of the P2P network. However, CDN-P2P systems alone do not guarantee the effectiveness of the services, since the peers output that are the only holders of a particular contents can generate congestion around the CDN server and degrade the quality of users experience. This dissertation investigates the contribution of stable peers for availability content on the on the P2P slice form a CDN-P2P system designed to distribute videos similar to those distributed by YouTube. In this way, the data were collected from the real YouTube Web site, exploring the potential of the users that have been access the playlists to characterize the stability of the peers in the system. The assumption about the effectiveness of playlists viewers int the availability content, due to the increased of the stay connnected of these users in the system and the possible popularity of contents shared by them. It was found that when a large number of the peers players pairs of the playlists spend long sessions connected, the improvement of the availability of content was in 60%. Additionally, in scenarios of low participation of players in playlists, its was the improvement outperformed in 20%. Furthermore, we evaluated how the build policies of the mesh impact the distribution system when the peers are grouped and identified as ordinaries and stable. These policies structure the portion of the P2P system through the criterias that are employed on arrival, maintenance and management of the connections of the peers, thus reducing the demands on the CDN server. / A escalabilidade e a alta demanda por recursos são os principais desafios que os provedores de conteúdo enfrentam na viabilização de aplicações multimídia baseadas em redes. No YouTube, por exemplo, um dos mais populares sistemas de distribuição de vídeo sob demanda, são enviadas 100 horas de vídeo a cada minuto aos seus servidores e mais de quatro bilhões de horas de vídeo são assistidas a cada mês. Sistemas CDN-P2P têm sido apontados como uma alternativa escalável para distribuição de conteúdo multimídia na Internet. Nesses sistemas, os pares da rede par-a-par (P2P) compartilham seus recursos, diminuindo as demandas sobre a infraestrutura da rede de distribuição de conteúdo (CDN). Por outro lado, os servidores da CDN garantem a disponibilidade de conteúdo quando as contribuições dos pares são limitadas pelo churn, ou quando o conteúdo for inédito aos pares da rede P2P. Contudo, sistemas CDN-P2P, por si só, não garantem a efetividade dos serviços, visto que a saída de pares que são os únicos detentores de um determinado conteúdo pode gerar congestionamento ao redor do servidor da CDN e degradar a qualidade de experiência dos usuários. Nesta dissertação investiga-se a contribuição de pares estáveis para disponibilidade de conteúdo na parte P2P de um sistema CDN-P2P concebido para distribuir vídeos similares aos distribuídos pelo YouTube. Para isso, dados reais foram coletados do site YouTube, explorando-se o potencial de usuários que acessam playlists para caracterizar a estabilidade dos pares no sistema. A suposição acerca da efetividade dos tocadores de playlists na disponibilidade de conteúdo deve-se Ao maior tempo de permanência desses usuários no sistema e á possível popularidade dos conteúdos por eles compartilhados. Verificou-se que quando um número grande de pares tocadores de playlists passam longas sessões conectados, a melhoria na disponibilidade de conteúdo foi de 60%. Adicionalmente em cenários de baixa participação dos tocadores de playlists a melhoria superou 20%. Em seguida, avaliou-se de que forma políticas de formação da malha impactam o sistema de distribuição estudado quando os pares são agrupados e identificados como estáveis e comuns. Estas políticas estruturam a porçãoP2P do sistema através de critérios que são empregados na chegada, na manutenção e gerência das conexões dos pares, diminuindo assim as exigências sobre o servidor da CDN.

There are some new challenges in system administration and design to optimize the resource management for a cloud based application. Some applications demand stringent performance requirements (e.g. delay and jitter bounds), while some applications exhibit bursty (volatile) workloads. This thesis proposes an epidemic model inspired (and continuous time Markov Chain based) framework, which can reproduce workload volatility namely the "buzz effects" (when there is a sudden increase of a content popularity) of a Video on Demand (VoD) system. Two estimation procedures (heuristic and a Markov Chain Monte Carlo (MCMC) based approach) have also been proposed in this work to calibrate the model against workload traces. Obtained model parameters from the calibration procedures reveal some interesting property of the model. Based on numerical simulations, precisions of both procedures have been analyzed, which show that both of them perform reasonably. However, the MCMC procedure outperforms the heuristic approach. This thesis also compares the proposed model with other existing models examining the goodness-of-fit of some statistical properties of real workload traces. Finally this work suggests a probabilistic resource provisioning approach based on a Large Deviation Principle (LDP). LDP statistically characterizes the buzz effects that causeextreme workload volatility. This analysis exploits the information obtained using the LDP of the VoD system for defining resource management policies. These policies may be of some interest to all stakeholders in the emerging context of cloud networking.

Submitted by Marcela Rodrigues do Amaral (marcela.rodrigues.amaral@gmail.com) on 2016-12-15T17:32:49Z No. of bitstreams: 1 O valor do Netflix para o consumidor brasileiro.pdf: 1259452 bytes, checksum: 4adf07af41b90d1afdbbd121db282c99 (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2016-12-21T18:40:20Z (GMT) No. of bitstreams: 1 O valor do Netflix para o consumidor brasileiro.pdf: 1259452 bytes, checksum: 4adf07af41b90d1afdbbd121db282c99 (MD5) / Made available in DSpace on 2017-01-04T17:13:36Z (GMT). No. of bitstreams: 1 O valor do Netflix para o consumidor brasileiro.pdf: 1259452 bytes, checksum: 4adf07af41b90d1afdbbd121db282c99 (MD5) Previous issue date: 2016-11-16 / The increase of internet penetration and mobility enabled the appearance of new players that offer online media subscription. Today Netflix is the largest of these players, with 87 subscribers around the world. The on demand model is already a reality for some Brazilian consumers. The option to customize the use of such platform changes the experience of the consumer, as it is possible to shape the users viewing experience to reflect their personal preferences and time availability. The objective of this dissertation is to understand the value that Netflix offers to the Brazilian consumer. To achieve this objective, other´s authors hypothesis were verified and new hypothesis were drawn. The conclusions were based on the answers of 225 responses to an online questionnaire, as well as some interviews. Among the main conclusions, we highlight three points. The first is that the greatest value for the consumers consisted in having the option to use the platform wherever and whenever they wished. The second point regards the kind of content offered: the international content was the highlight for being the most watched, while consumers indicated that the sports and news content was in short supply. The third point was a suggestion for a possible improvement to the product. The answers indicate that consumers would also like to have the ability to use the platform while offline. This point was indicated mainly because of the poor internet service in Brazil, which could momentarily block the access to online streaming services. / O aumento da penetração da internet e da mobilidade possibilitou o surgimento de novos players na distribuição de vídeo por assinatura. Atualmente, o maior deles é o Netflix, com 87 milhões de assinantes no mundo. O modelo sob demanda já é uma realidade para alguns brasileiros e muda a experiência do usuário na medida em que cada um elabora sua própria programação com base nos seus gostos pessoais, sua disponibilidade de tempo e preferências sobre o dispositivo que será utilizado para tal finalidade. Este trabalho teve como objetivo compreender o que é valor para o consumidor do Netflix no Brasil. Para isso, foram verificadas hipóteses que outros autores já apontaram como valor para consumidores do Netflix e novos pontos foram levantados. As conclusões foram baseadas nas 225 respostas de um questionário online e em algumas entrevistas presenciais. Dentre as principais conclusões podemos destacar três pontos. O primeiro é que a característica com maior valor para os consumidores foi a liberdade de poder assistir quando e onde quiserem. O segundo foi em relação ao tipo de conteúdo ofertado e consumido: o conteúdo internacional se destacou como o mais assistido e consumidores indicaram uma lacuna de conteúdo esportivo e jornalístico no serviço. O terceiro foi uma sugestão de melhoria no produto que está relacionado com a possibilidade de assistir offline. Esse ponto foi levantado por diversos participantes da pesquisa, que indicaram que a conexão precária da internet no Brasil poderia impedir o acesso em alguns momentos.

Made available in DSpace on 2015-04-11T14:03:13Z (GMT). No. of bitstreams: 1 DISSERTACAO JOAO DA MATA.pdf: 5833486 bytes, checksum: fd81987d9b1e9ac8f9bb648058db273b (MD5) Previous issue date: 2012-03-22 / Fundação de Amparo à Pesquisa do Estado do Amazonas / Scalability and high demand for resources are the main challenges that content providers face to deploy Video-on-Demand applications. The most popular site for sharing videos, YouTube, has over 4 billion videos viewed a day and 60 hours of video are uploaded every minute. Hybrid systems (CDN-P2P) have been proposed as a scalable and cost effective solution for VoD distribution. In these systems, peers share their resources decreasing demand on the content distribution network infrastructure (CDN). On the other hand, the CDN s servers guarantee the availability of content when peers contributions are limited by churn. However, in these systems, the content distributed must be managed so that the CDN servers workload is minimized. An issue to be investigated is the impact of churn, i.e the effect of cycle of peers join and leave, on management policies. Carried studies showed that the performance of policies improves as the storage capacity of peers increases. However, this increasement does not impact proportionately the performance of policies. Later on, we proposed, implemented and evaluated four object management policies derived from data in YouTube video collections. These policies use information left by users or generated by the video distribution system to measure the value of objects. We found that the proposed policies were able to improve the availability of content in more than 70%, compared to the LFU policy, and more than 50% compared to GDSP policy. / A escalabilidade e a alta demanda por recursos s ao os principais desafios que os provedores de conte´udo enfrentam na viabiliza¸c ao de aplica¸c oes de v´ıdeos sob demanda (VoD). O site mais popular de compartilhamento de v´ıdeos, o YouTube, tem mais de 4 bilh oes de visualiza¸c oes por dia e 60 horas de v´ıdeo s ao armazenadas a cada minuto em seus servidores. Sistemas h´ıbridos (CDN-P2P) t em sido apresentado como uma solu¸c ao escal´avel para distribui¸c ao de VoD. Nesses sistemas, pares compartilham seus recursos diminuindo a demanda sobre a infraestrutura da rede de distribui¸c ao de conte´udo (CDN). Por outro lado, os servidores da CDN garantem a disponibilidade de conte´udo quando as contribui¸c oes dos pares s ao limitadas pelo churn, ou quando o conte´udo for in´edito aos pares da rede par a par (P2P). No entanto, o conte´udo distribu´ıdo nesses sistemas precisa ser gerenciado, de forma que a carga de trabalho submetida aos servidores da CDN seja minimizada. Uma quest ao a ser investigada nesse sistema ´e o impacto do churn, isto ´e, o efeito criado pelo ciclo de entrada e sa´ıda dos pares sobre os mecanismos de ger encia do conte´udo distribu´ıdo pelo sistema. Nesta disserta¸c ao avalia-se o impacto do churn no desempenho de pol´ıticas de gerenciamento de objetos em sistemas CDN-P2P; verificou-se que o impacto no desempenho das pol´ıticas diminui com o aumento da capacidade de armazenamento dos pares, no entanto, esse aumento n ao impacta proporcionalmente a performance das pol´ıticas. Em seguida, s ao propostas, implementadas e avaliadas quatro pol´ıticas de gerenciamento de objetos derivadas a partir de dados reais obtidos de cole¸c oes de v´ıdeos do YouTube. Essas pol´ıticas exploram informa¸c oes deixadas pelos usu´arios ou geradas pelo sistema de distribui¸c ao dos v´ıdeos para mensurar o valor de um objeto. A suposi¸c ao acerca da efetividade dessas informa¸c oes na valora¸c ao dos objetos ´e devido `a influ encia do sistema de recomenda¸c ao do YouTube no acesso a seu conte´udo, pois esse sistema utiliza-se dessas informa¸c oes para indicar v´ıdeos aos usu´arios. As pol´ıticas propostas foram capazes de melhorar a disponibilidade do conte´udo em mais de 70%, comparada `a disponibilidade proporcionada pela pol´ıtica LFU e mais de 50%, comparada `a pol´ıtica GDSP.

The media landscape is changing and Internet-based streaming services for children are becoming increasingly popular. The concept of online streaming extends freedom and control over content selection but discovering new content is often experienced as troublesome. The objective of this thesis is to identify parameters to make it easier for users of streaming services for children to discover and watch unfamiliar programs. Guidelines are formed based on literature studies, interviews, observations, a survey, a benchmark, data analysis with Adobe Analytics, a workshop and finally user tests with prototypes. These guidelines conclude that content should be categorized, dynamicized, highlighted and socially engaging. Categorization based on age is primarily important but interests and genres can also be used to make children more interested in a title. Content should be dynamic, customizable and personal to each user to give more accurate recommendations based on age and interests. Making one alternative more visually prominent will make this alternative more interesting especially for younger children and social features with information about other users opinions can motivate a decision to discover new content among older children.

With the recent release of head-mounted displays for consumers, virtual reality experiences are more accessible than ever. However, there is still a shortage of research concerning how to design user interfaces in virtual reality for good experiences. This thesis focuses on what aspects should be considered when designing a graphical user interface in virtual reality - controlled by head orientation input - for a qualitative user experience. The research has included a heuristic evaluation, interviews, usability tests, and a survey. A virtual reality prototype of a video on demand service was investigated and served as the application for the research. Findings from the analysis of the data were application specific pragmatic and hedonic goals of the users, relevant to the subjective user experience, and current user experience problems with the prototype tested. In combination with previous recommendations, the result led to the development of seven guidelines. However, these guidelines are considered only to serve as a foundation for future research since they need to be validated. New head-mounted displays and virtual reality applications are released every day and with the increasing number of users, there will be a continuous need for more research.

The work is focused on the influence of movie and video production in connection with the new media. It is focused to map how the new media influenced the distribution of movie and video production, depending on their use on the market. The work defines the basic concepts and direction of new media. Characterizes the divergence of terms like old and new media, what are their differences, specifics and how they change film and video distribution channels. It creates complete list and comparison of existing providers of video on demand services. It brings up specified criteria and on base of them compares the most popular video hosting sites. The work includes and specify other channels, which facilitate the spread of film or video and was build up by Web 2.0. Because of the frequent encounters of the Copyright Act in connection with the illegal distribution, especially in the film, this theme is also included in the content.

Aim of the thesis is to design and implement unique service based on the newest technologies in web apps fi eld which allows screen recording followed by P2P distribution between participating users using web browser only. Thesis deals with the analysis of modern and coming technologies which allow practical implementation of such a service. It involves obtaining access to the screen source data, its recording, transforming and transmission over the network followed by playing on the other side. Recorded videos are adapted for part by part use in a player with seeking capability. Distributed architecture for data exchange between peers using peer-to-peer connection based on hybrid P2P VoD network provides scalability of the solution. The player allows obtaining the necessary parts of the videos from the current watchers with smooth video playback experience during ongoing transmissions whilst allowing arbitrary video shifting. In consideration of early stages of development or experimental support for some of the APIs needed for this work, research into browsers' support with discussion on realistic applicability nowadays is always performed.

This diploma thesis deals with the current phenomenon of video on-demand and the strategy of the streaming company Netflix when entering the European market. In the opening chapters it is necessary to explain the boom of the video on-demand services (VoD) in the context of television history and its position in relation to traditional linear broadcasting. Subsequently, the dramaturgical line and the programming offer of the company are presented , which is undoubtedly a competitive advantage of Netflix. In this context, Netflix's biggest competitors and their approach to production of original content are mentioned. The challenges Netflix is facing in its international expansion are also mentioned, including the need to tailor its offer and produce local content when entering new markets. Afterwards the European market as a whole is analyzed with regard to the specificities of the region and the key steps that were necessary to successfully start doing business on the continent. Last but not least, the thesis examines the position and development tendencies of Netflix in the field of original production in selected three European markets - Norway, France and the Czech Republic. In this part, Netflix is compared to other VoD competitors in these markets as well as by established players such as...

[pt] Esta pesquisa tem como tema as transformações do audiovisual sob o viés do design, a partir da digitalização dos suportes, conectividade e convergência das mídias. Esta digitalização trouxe uma série de mudanças na cadeia produtiva e na experiência audiovisual. A pesquisa busca elucidar, neste contexto de convergência de mídias, como são ressignificados os elementos de design. Partindo do pressuposto de que, na medida em que novos suportes elaboram novas condições e novos hábitos, os elementos de design são ressignificados em suas aplicações. A dissertação tem como objetivo compreender como os elementos do design se comportam em um novo cenário digital, aponta como as transformações tecnológicas afetam a experiência e analisa essas transformações no design, nas possibilidades de interatividade, no videografismo e na passagem para a tridimensionalidade. Apresenta, ainda, tendências da aplicação do design em vídeo sob demanda e em variações tecnológicas. Explora aspectos da narrativa não linear em suportes de imagens em movimento e apresenta um experimento em realidade virtual, realizado de forma colaborativa e interdisciplinar. Esta é uma pesquisa exploratória com abordagem qualitativa e alguns experimentos práticos que observam a aplicação do design nos diferentes meios. / [en] This research is about the transformations in audiovisual, under design s perspective, which are consequences from the digitalization of media, connectivity, and media convergence. The digitalization phenomenon has arisen a considerable number of transformations into productive chains as well as in audiovisual experience. This research tries to elucidate, in this context of media convergence, how design elements are reframed. Based on the assumption that new media may conduct to new conditions and new habits, the design elements are reframed and transformed by its applications in the audiovisual products. This dissertation aims to understand how design elements behave in a new digital audiovisual scenario, pointing out how technological transformations affect the experience, and analyzing these transformations into the design field, into possibilities of interaction, motion graphics and the transition to tridimensional. It also presents some trends of design applications into video on demand and new technological possibilities, exploring implications of using nonlinear narratives in moving image media. Also, this dissertation presents an experiment in virtual reality which was a result of a collaborative and interdisciplinary effort. This is an exploratory research based on quality approach and it presents some case studies related to design applications in various media.