A component framework for personalized multimedia applications

Eine praktikable Unterstützung für eine dynamische Erstellung von personalisierten Multimedia-Präsentationen bieten bisher weder industrielle Lösungen noch Forschungsansätze. Mit dem Software-technischen Ansatz des MM4U-Frameworks („MultiMedia For You“) wird erstmals eine generische und zugleich praktikable Unterstützung für den dynamischen Erstellungsprozess bereitgestellt. Das Ziel des MM4U-Frameworks ist es den Anwendungsentwicklern eine umfangreiche und anwendungsunabhängige Unterstützung zur Erstellung von personalisierten Multimedia-Inhalten anzubieten und damit den Entwicklungsprozess solcher Anwendungen erheblich zu erleichtern. Um das Ziel eines Software-Frameworks zur generischen Unterstützung der Entwicklung von personalisierten Multimedia-Anwendungen zu erreichen, stellt sich die Frage nach einer geeigneten Software-technischen Unterstützung zur Entwicklung eines solchen Frameworks. Seit der Einführung von objektorientierten Frameworks, ist heute die Entwicklung immer noch aufwendig und schwierig. Um die Entwicklungsrisiken zu reduzieren, sind geeignete Vorgehensmodelle und Entwicklungsmethoden erstellt worden. Mit der Komponenten-Technologie sind auch so genannte Komponenten-Frameworks entstanden. Im Gegensatz zu objekt-orientierten Frameworks fehlt derzeit jedoch ein geeignetes Vorgehensmodell für Komponenten-Frameworks. Um den Entwicklungsprozess von Komponenten-Frameworks zu verbessern ist mit ProMoCF („Process Model for Component Frameworks“) ein neuartiger Ansatz entwickelt worden. Hierbei handelt es sich um ein leichtgewichtiges Vorgehensmodell und eine Entwicklungsmethodik für Komponenten-Frameworks. Das Vorgehensmodell wurde unter gegenseitigem Nutzen mit der Entwicklung des MM4U-Frameworks erstellt. Das MM4U-Framework stellt keine Neuerfindung der Adaption von Multimedia-Inhalten dar, sondern zielt auf die Vereinigung und Einbettung existierender Forschungsansätze und Lösungen im Umfeld der Multimedia-Personalisierung. Mit so einem Framework an der Hand können Anwendungsentwickler erstmals effizient und einfach eine dynamische Erstellung ihrer personalisierten Multimedia-Inhalte realisieren

Model driven design and data integration in semantic web information systems

The Web is quickly evolving in many ways. It has evolved from a Web of documents into a Web of applications in which a growing number of designers offer new and interactive Web applications with people all over the world. However, application design and implementation remain complex, error-prone and laborious. In parallel there is also an evolution from a Web of documents into a Web of `knowledge' as a growing number of data owners are sharing their data sources with a growing audience. This brings the potential new applications for these data sources, including scenarios in which these datasets are reused and integrated with other existing and new data sources. However, the heterogeneity of these data sources in syntax, semantics and structure represents a great challenge for application designers. The Semantic Web is a collection of standards and technologies that offer solutions for at least the syntactic and some structural issues. If offers semantic freedom and flexibility, but this leaves the issue of semantic interoperability. In this thesis we present Hera-S, an evolution of the Model Driven Web Engineering (MDWE) method Hera. MDWEs allow designers to create data centric applications using models instead of programming. Hera-S especially targets Semantic Web sources and provides a flexible method for designing personalized adaptive Web applications. Hera-S defines several models that together define the target Web application. Moreover we implemented a framework called Hydragen, which is able to execute the Hera-S models to run the desired Web application. Hera-S' core is the Application Model (AM) in which the main logic of the application is defined, i.e. defining the groups of data elements that form logical units or subunits, the personalization conditions, and the relationships between the units. Hera-S also uses a so-called Domain Model (DM) that describes the content and its structure. However, this DM is not Hera-S specific, but instead allows any Semantic Web source representation as its DM, as long as its content can be queried by the standardized Semantic Web query language SPARQL. The same holds for the User Model (UM). The UM can be used for personalization conditions, but also as a source of user-related content if necessary. In fact, the difference between DM and UM is conceptual as their implementation within Hydragen is the same. Hera-S also defines a presentation model (PM) which defines presentation details of elements like order and style. In order to help designers with building their Web applications we have introduced a toolset, Hera Studio, which allows to build the different models graphically. Hera Studio also provides some additional functionality like model checking and deployment of the models in Hydragen. Both Hera-S and its implementation Hydragen are designed to be flexible regarding the user of models. In order to achieve this Hydragen is a stateless engine that queries for relevant information from the models at every page request. This allows the models and data to be changed in the datastore during runtime. We show that one way to exploit this flexibility is by applying aspect-orientation to the AM. Aspect-orientation allows us to dynamically inject functionality that pervades the entire application. Another way to exploit Hera-S' flexibility is in reusing specialized components, e.g. for presentation generation. We present a configuration of Hydragen in which we replace our native presentation generation functionality by the AMACONT engine. AMACONT provides more extensive multi-level presentation generation and adaptation capabilities as well aspect-orientation and a form of semantic based adaptation. Hera-S was designed to allow the (re-)use of any (Semantic) Web datasource. It even opens up the possibility for data integration at the back end, by using an extendible storage layer in our database of choice Sesame. However, even though theoretically possible it still leaves much of the actual data integration issue. As this is a recurring issue in many domains, a broader challenge than for Hera-S design only, we decided to look at this issue in isolation. We present a framework called Relco which provides a language to express data transformation operations as well as a collection of techniques that can be used to (semi-)automatically find relationships between concepts in different ontologies. This is done with a combination of syntactic, semantic and collaboration techniques, which together provide strong clues for which concepts are most likely related. In order to prove the applicability of Relco we explore five application scenarios in different domains for which data integration is a central aspect. This includes a cultural heritage portal, Explorer, for which data from several datasources was integrated and was made available by a mapview, a timeline and a graph view. Explorer also allows users to provide metadata for objects via a tagging mechanism. Another application is SenSee: an electronic TV-guide and recommender. TV-guide data was integrated and enriched with semantically structured data from several sources. Recommendations are computed by exploiting the underlying semantic structure. ViTa was a project in which several techniques for tagging and searching educational videos were evaluated. This includes scenarios in which user tags are related with an ontology, or other tags, using the Relco framework. The MobiLife project targeted the facilitation of a new generation of mobile applications that would use context-based personalization. This can be done using a context-based user profiling platform that can also be used for user model data exchange between mobile applications using technologies like Relco. The final application scenario that is shown is from the GRAPPLE project which targeted the integration of adaptive technology into current learning management systems. A large part of this integration is achieved by using a user modeling component framework in which any application can store user model information, but which can also be used for the exchange of user model data

Ubiquitous User Modeling

More and more interactions take place between humans and mobile or connected IT-systems in daily life. This offers a great opportunity, especially to user modeling, to reach better adaptation with ongoing evaluation of user behavior. This work develops a complete framework to realize the newly defined concept of ubiquitous user modeling. The developed tools cover methods for the uniform exchange and the semantic integration of partial user models. They also account for the extended needs for privacy and the right of every human for introspection and control of their collected data. The SITUATIONALSTATEMENTS and the exchange language USERML have been developed on the syntactical level, while the general user model ontology GUMO and the UBISWORLD ontology have been developed on the semantical level. A multilevel conflict resolution method, which handles the problem of contradictory statements, has been implemented together with a web-based user model service, such that the road capability and the scalability can be proven with this approach.Immer häufiger auftretende Interaktionen im täglichen Leben zwischen Menschen und vernetzten oder mobilen IT-Systemen bieten insbesondere für die Benutzermodellierung eine große Chance, durch ständige Evaluation des Benutzerverhaltens verbesserte Adaptionsleistungen zu erzielen. Die vorliegende Arbeit entwickelt ein komplettes Rahmensystem, um dieses neu definierte Konzept der ubiquitären Benutzermodellierung zu realisieren. Die erarbeiteten Werkzeuge umfassen Methoden zum einheitlichen Austausch und zur semantischen Integration von partiellen Benutzermodellen. Sie berücksichtigen aber auch die erhöhten Anforderungen an die Privatsphäre, sowie das Recht der Menschen auf Introspektion und Kontrolle über die erhobenen Daten. Auf syntaktischer Ebene werden die situationsbeschreibenden Aussagen sowie die Austauschsprache UserML entworfen. Auf semantischer Ebene werden die allgemeine Benutzermodell-Ontologie GUMO und die UBISWELT-Ontologie entwickelt. Ein mehrstufiger Konfliktlösungsmechanismus, der das Problem sich widersprechender Aussagen bearbeitet, wird zusammen mit einem webbasierten Benutzermodell-Service implementiert, sodass die Praxistauglichkeit und die Skalierbarkeit dieses Ansatzes an mehreren Beispielen gezeigt werden kann

Self-adaptation via concurrent multi-action evaluation for unknown context

Context-aware computing has been attracting growing attention in recent years. Generally, there are several ways for a context-aware system to select a course of action for a particular change of context. One way is for the system developers to encompass all possible context changes in the domain knowledge. Other methods include system inferences and adaptive learning whereby the system executes one action and evaluates the outcome and self-adapts/self-learns based on that. However, in situations where a system encounters unknown contexts, the iterative approach would become unfeasible when the size of the action space increases. Providing efficient solutions to this problem has been the main goal of this research project. Based on the developed abstract model, the designed methodology replaces the single action implementation and evaluation by multiple actions implemented and evaluated concurrently. This parallel evaluation of actions speeds up significantly the evolution time taken to select the best action suited to unknown context compared to the iterative approach. The designed and implemented framework efficiently carries out concurrent multi-action evaluation when an unknown context is encountered and finds the best course of action. Two concrete implementations of the framework were carried out demonstrating the usability and adaptability of the framework across multiple domains. The first implementation was in the domain of database performance tuning. The concrete implementation of the framework demonstrated the ability of concurrent multi-action evaluation technique to performance tune a database when performance is regressed for an unknown reason. The second implementation demonstrated the ability of the framework to correctly determine the threshold price to be used in a name-your-own-price channel when an unknown context is encountered. In conclusion the research introduced a new paradigm of a self-adaptation technique for context-aware application. Among the existing body of work, the concurrent multi-action evaluation is classified under the abstract concept of experiment-based self-adaptation techniques

How To Touch a Running System

The increasing importance of distributed and decentralized software architectures entails more and more attention for adaptive software. Obtaining adaptiveness, however, is a difficult task as the software design needs to foresee and cope with a variety of situations. Using reconfiguration of components facilitates this task, as the adaptivity is conducted on an architecture level instead of directly in the code. This results in a separation of concerns; the appropriate reconfiguration can be devised on a coarse level, while the implementation of the components can remain largely unaware of reconfiguration scenarios. We study reconfiguration in component frameworks based on formal theory. We first discuss programming with components, exemplified with the development of the cmc model checker. This highly efficient model checker is made of C++ components and serves as an example for component-based software development practice in general, and also provides insights into the principles of adaptivity. However, the component model focuses on high performance and is not geared towards using the structuring principle of components for controlled reconfiguration. We thus complement this highly optimized model by a message passing-based component model which takes reconfigurability to be its central principle. Supporting reconfiguration in a framework is about alleviating the programmer from caring about the peculiarities as much as possible. We utilize the formal description of the component model to provide an algorithm for reconfiguration that retains as much flexibility as possible, while avoiding most problems that arise due to concurrency. This algorithm is embedded in a general four-stage adaptivity model inspired by physical control loops. The reconfiguration is devised to work with stateful components, retaining their data and unprocessed messages. Reconfiguration plans, which are provided with a formal semantics, form the input of the reconfiguration algorithm. We show that the algorithm achieves perceived atomicity of the reconfiguration process for an important class of plans, i.e., the whole process of reconfiguration is perceived as one atomic step, while minimizing the use of blocking of components. We illustrate the applicability of our approach to reconfiguration by providing several examples like fault-tolerance and automated resource control

Situated interaction on spatial topics

In this thesis, we present a model and an implementation to handle situational interactions on spatial topics as well as several adaptation strategies to cope with common problems in real-world applications. The model is designed to incorporate situational factors in spatial reasoning processes at the basic level and to facilitate its use in a wide range of applications. The implementation realizing the model corresponds very closely to the structure of the model, and was put to test in a scenario of a mobile tourist guide. The adaptation strategies address the lack of information, resource restrictions as well as the problem of varying availability and quality of positional information.In dieser Arbeit stellen wir ein Modell zur Verarbeitung situierter Interaktionen über raumbezogene Sachverhalte und seine Implementation vor. Außerdem präsentieren wir verschiedene Strategien zum Umgang mit häufigen Problemen, die im Zusammenhang mit dem (mobilen) Einsatz von Systemen im realen Umfeld auftreten. Das zu Grunde liegende Modell bezieht situationsbezogene Faktoren auf unterster Ebene mit ein und erleichtert durch den modularen Aufbau seinen Einsatz im Rahmen verschiedener Anwendungen. Die entsprechende Implementation spiegelt die Struktur des Modells wider und wurde im Rahmen eines mobilen Touristenführers getestet. Die ebenfalls vorgestellten Adaptionsstrategien dienen unter anderem zur Behandlung von Informationsmangel und von Ressourcenbeschränkungen sowie zum Umgang mit dem Problem variierender Verfügbarkeit und Qualität von Positionsinformation

Migrating characters: effective user guidance in instrumented environments

The work at hand deals with the conceptual design as well as with the realization of virtual characters, which, unlike previous works in this research area, are not limited to a use in virtual worlds. The presented Migrating Character approach on the contrary allows virtual characters to act and interact with the physical world. Different technical solutions allowing a Migrating Character to move throughout physical space, either completely autonomously or in conjunction with a user, are introduced and discussed as well as resulting implications for the characters behavior. While traditional virtual characters are acting in a well defined virtual world, Migrating Characters need to adapt to changing environmental setups in a very flexible way. A Migrating Character must be capable of determining these environmental changes by means of sensors. Furthermore, based on this data, an adequate adaptation of the characters behavior has to be realized. Apart from a theoretical discussion of the necessary enhancements of a virtual character when taking the step from virtual to real worlds, different exemplary Migrating Character implementations are introduced in the course of the work.Die vorliegende Arbeit beschäftigt sich mit dem konzeptuellen Entwurf und der technischen Realisierung von virtuellen Charakteren, die im Gegensatz zu bisherigen Arbeiten auf diesem Gebiet nicht auf den Einsatz in virtuellen Welten beschränkt sind. Der vorgestellte Migrating Character Ansatz erlaubt virtuellen Charakteren vielmehr in der physikalischen Welt zu agieren und zu interagieren. Verschiedene technische Lösungen, welche es einem Migrating Character ermöglichen sich in der physikalischen Welt autonom bzw. in Abhängigkeit vom Benutzer zu bewegen, sind ebenso Gegenstand der Arbeit wie eine ausführliche Diskussion der daraus für das Verhalten des virtuellen Charakters resultierenden Implikationen. Während sich traditionelle virtuelle Charaktere in einer wohl definierten virtuellen Umgebung bewegen, muss ein Migrating Character flexibel auf sich ändernde Umgebungsbedingungen reagieren. Aus sensorischer Sicht benötigt ein Migrating Character also die Fähigkeit eine sich ändernde physikalische Situation zu erkennen. Basierend auf diesen Daten muss weiterhin eine adäquate Anpassung des Verhaltens des Migrating Characters geschehen. Neben einer theoretischen Diskussion der notwendigen Erweiterungen eines virtuellen Charakters beim übergang von virtueller zu realer Umgebung werden auch exemplarische Migrating Character Implementierungen vorgestellt