Persönliche Wege der Interaktion mit multimedialen Inhalten

Today the world of multimedia is almost completely device- and content-centered. It focuses it’s energy nearly exclusively on technical issues such as computing power, network specifics or content and device characteristics and capabilities. In most multimedia systems, the presentation of multimedia content and the basic controls for playback are main issues. Because of this, a very passive user experience, comparable to that of traditional TV, is most often provided. In the face of recent developments and changes in the realm of multimedia and mass media, this ”traditional” focus seems outdated. The increasing use of multimedia content on mobile devices, along with the continuous growth in the amount and variety of content available, make necessary an urgent re-orientation of this domain. In order to highlight the depth of the increasingly difficult situation faced by users of such systems, it is only logical that these individuals be brought to the center of attention. In this thesis we consider these trends and developments by applying concepts and mechanisms to multimedia systems that were first introduced in the domain of usercentrism. Central to the concept of user-centrism is that devices should provide users with an easy way to access services and applications. Thus, the current challenge is to combine mobility, additional services and easy access in a single and user-centric approach. This thesis presents a framework for introducing and supporting several of the key concepts of user-centrism in multimedia systems. Additionally, a new definition of a user-centric multimedia framework has been developed and implemented. To satisfy the user’s need for mobility and flexibility, our framework makes possible seamless media and service consumption. The main aim of session mobility is to help people cope with the increasing number of different devices in use. Using a mobile agent system, multimedia sessions can be transferred between different devices in a context-sensitive way. The use of the international standard MPEG-21 guarantees extensibility and the integration of content adaptation mechanisms. Furthermore, a concept is presented that will allow for individualized and personalized selection and face the need for finding appropriate content. All of which can be done, using this approach, in an easy and intuitive way. Especially in the realm of television, the demand that such systems cater to the need of the audience is constantly growing. Our approach combines content-filtering methods, state-of-the-art classification techniques and mechanisms well known from the area of information retrieval and text mining. These are all utilized for the generation of recommendations in a promising new way. Additionally, concepts from the area of collaborative tagging systems are also used. An extensive experimental evaluation resulted in several interesting findings and proves the applicability of our approach. In contrast to the ”lean-back” experience of traditional media consumption, interactive media services offer a solution to make possible the active participation of the audience. Thus, we present a concept which enables the use of interactive media services on mobile devices in a personalized way. Finally, a use case for enriching TV with additional content and services demonstrates the feasibility of this concept.Die heutige Welt der Medien und der multimedialen Inhalte ist nahezu ausschließlich inhalts- und geräteorientiert. Im Fokus verschiedener Systeme und Entwicklungen stehen oft primär die Art und Weise der Inhaltspräsentation und technische Spezifika, die meist geräteabhängig sind. Die zunehmende Menge und Vielfalt an multimedialen Inhalten und der verstärkte Einsatz von mobilen Geräten machen ein Umdenken bei der Konzeption von Multimedia Systemen und Frameworks dringend notwendig. Statt an eher starren und passiven Konzepten, wie sie aus dem TV Umfeld bekannt sind, festzuhalten, sollte der Nutzer in den Fokus der multimedialen Konzepte rücken. Um dem Nutzer im Umgang mit dieser immer komplexeren und schwierigen Situation zu helfen, ist ein Umdenken im grundlegenden Paradigma des Medienkonsums notwendig. Durch eine Fokussierung auf den Nutzer kann der beschriebenen Situation entgegengewirkt werden. In der folgenden Arbeit wird auf Konzepte aus dem Bereich Nutzerzentrierung zurückgegriffen, um diese auf den Medienbereich zu übertragen und sie im Sinne einer stärker nutzerspezifischen und nutzerorientierten Ausrichtung einzusetzen. Im Fokus steht hierbei der TV-Bereich, wobei die meisten Konzepte auch auf die allgemeine Mediennutzung übertragbar sind. Im Folgenden wird ein Framework für die Unterstützung der wichtigsten Konzepte der Nutzerzentrierung im Multimedia Bereich vorgestellt. Um dem Trend zur mobilen Mediennutzung Sorge zu tragen, ermöglicht das vorgestellte Framework die Nutzung von multimedialen Diensten und Inhalten auf und über die Grenzen verschiedener Geräte und Netzwerke hinweg (Session mobility). Durch die Nutzung einer mobilen Agentenplattform in Kombination mit dem MPEG-21 Standard konnte ein neuer und flexibel erweiterbarer Ansatz zur Mobilität von Benutzungssitzungen realisiert werden. Im Zusammenhang mit der stetig wachsenden Menge an Inhalten und Diensten stellt diese Arbeit ein Konzept zur einfachen und individualisierten Selektion und dem Auffinden von interessanten Inhalten und Diensten in einer kontextspezifischen Weise vor. Hierbei werden Konzepte und Methoden des inhaltsbasierten Filterns, aktuelle Klassifikationsmechanismen und Methoden aus dem Bereich des ”Textminings” in neuer Art und Weise in einem Multimedia Empfehlungssystem eingesetzt. Zusätzlich sind Methoden des Web 2.0 in eine als Tag-basierte kollaborative Komponente integriert. In einer umfassenden Evaluation wurde sowohl die Umsetzbarkeit als auch der Mehrwert dieser Komponente demonstriert. Eine aktivere Beteiligung im Medienkonsum ermöglicht unsere iTV Komponente. Sie unterstützt das Anbieten und die Nutzung von interaktiven Diensten, begleitend zum Medienkonsum, auf mobilen Geräten. Basierend auf einem Szenario zur Anreicherung von TV Sendungen um interaktive Dienste konnte die Umsetzbarkeit dieses Konzepts demonstriert werden

Architectural support for ubiquitous access to multimedia content

Tese de doutoramento. Engenharia Electrotécnica e de Computadores (Telecomunicações). Faculdade de Engenharia. Universidade do Porto. 200

Sistema de recomendação e personalização de televisão

Com a expansão da Televisão Digital e a convergência entre os meios de difusão convencionais e a televisão sobre IP, o número de canais disponíveis tem aumentado de forma gradual colocando o espectador numa situação de difícil escolha quanto ao programa a visionar. Sobrecarregados com uma grande quantidade de programas e informação associada, muitos espectadores desistem sistematicamente de ver um programa e tendem a efectuar zapping entre diversos canais ou a assistir sempre aos mesmos programas ou canais. Diante deste problema de sobrecarga de informação, os sistemas de recomendação apresentam-se como uma solução. Nesta tese pretende estudar-se algumas das soluções existentes dos sistemas de recomendação de televisão e desenvolver uma aplicação que permita a recomendação de um conjunto de programas que representem potencial interesse ao espectador. São abordados os principais conceitos da área dos algoritmos de recomendação e apresentados alguns dos sistemas de recomendação de programas de televisão desenvolvidos até à data. Para realizar as recomendações foram desenvolvidos dois algoritmos baseados respectivamente em técnicas de filtragem colaborativa e de filtragem de conteúdo. Estes algoritmos permitem através do cálculo da similaridade entre itens ou utilizadores realizar a predição da classificação que um utilizador atribuiria a um determinado item (programa de televisão, filme, etc.). Desta forma é possível avaliar o nível de potencial interesse que o utilizador terá em relação ao respectivo item. Os conjuntos de dados que descrevem as características dos programas (título, género, actores, etc.) são armazenados de acordo com a norma TV-Anytime. Esta norma de descrição de conteúdo multimédia apresenta a vantagem de ser especificamente vocacionada para conteúdo audiovisual e está disponível livremente. O conjunto de recomendações obtidas é apresentado ao utilizador através da interacção com uma aplicação Web que permite a integração de todos os componentes do sistema. Para validação do trabalho foi considerado um dataset de teste designado de htrec2011-movielens-2k e cujo conteúdo corresponde a um conjunto de filmes classificados por diversos utilizadores num ambiente real. Este conjunto de filmes possui, para além da classificações atribuídas pelos utilizadores, um conjunto de dados que descrevem o género, directores, realizadores e país de origem. Para validação final do trabalho foram realizados diversos testes dos quais o mais relevante correspondeu à avaliação da distância entre predições e valores reais e cujo objectivo é classificar a capacidade dos algoritmos desenvolvidos preverem com precisão as classificações que os utilizadores atribuiriam aos itens analisados.With the expansion of Digital Television and convergence between conventional broadcasters and television over IP, the number of available channels has increased gradually putting the viewer in a situation of difficult choices about the program to watch. Overloaded with a lot of programs, many viewers systematically give up watching a program and tend to make zapping between different channels or always watch the same shows or channels. Faced with this problem of information overload, the recommendation systems stand out as a solution. This thesis aims to look into some of the existing solutions for TV recommender systems and to develop an application that allows the recommendations of a set of programs have potential interest to the viewer. It will examine the principal concepts in the area of recommendation systems as well as some of the recommender systems for television programs developed to date. To carry out the recommendations, two algorithms will be developed based on collaborative filtering and content filtering. These algorithms calculate the similarity between items or users to make the prediction of the rating a user would assign to a particular item (television, film, etc.). Thus it is possible to evaluate the level of potential interest that a user will have in relation to a specific item. The data sets that describe the characteristics of programs (title, genre, actors, etc.) are stored according to the TV-Anytime standard. This standard of multimedia content description has the advantage of being specifically geared towards audiovisual content as well as of being a freely available standard. The defined set of recommendations will be presented to the user through a Web application that guarantees the interoperability of the full set of software implemented. To validate the work, an existing dataset designated htrec2011-2k-movielens and whose content corresponds to a set of films classified by multiple users in a real environment was considered. This set of films has, in addition to the ratings given by users, a set of data describing the genre, directors, producers and country of origin. For the final validation of the work, different tests were carried out. The most important corresponds to the evaluation of the distance between predictions and the real evaluation scores. The objective is to classify the ability of the algorithms developed to predict the ratings that users give to items analyzed

Semantic discovery and reuse of business process patterns

Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modelling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. As a statement of research-in-progress this paper focuses on business process patterns and proposes an initial methodological framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework borrows ideas from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse