This thesis presents optimization techniques for efficient rendering of complex scenes on mobile devices. The introductory part of the text describes Unity game engine and the topic of mobile game development using this tool. Then follows a presentation of important optimization principles and methods for terrain rendering, large scale rendering of animated objects, rendering of animated water surfaces and of other elements in the scenes. The described methods include both general principles of optimization and specific optimization approaches based on the features of Unity game engine. The implementation of presented methods is described and used in practice in the context of mobile strategy game development.

This thesis deals with the problem of foreground extraction on mobile devices. The main goal of this project is to find or design segmentation methods for separating a user-selected object from an image (or video). The main requirement of these methods is the image processing time and segmentation quality. Some existing solutions of this problem are mentioned and their usability on mobile devices is discussed. A mobile application is created within the project, demonstrating the implemented real time foreground extraction algorithm.

The article considers three main aspects of developing mobile learning for serious learning scenarios at universities and further educational training sectors. The first is about getting in touch with mobile learning in general and analysing actual e-learning-systems at the Technische Universität Dresden. The second aspect focuses on micro learning as a potential didactical approach. Having a look on prototyping pitfalls and problems will complete the introduction. For discussing the presented issues concerning technical, didactical, learning and teaching problems there will be a workshop session with three round tables using the worldcafé method.

Die Vernetzung einer Vielzahl unterschiedlicher Nutzergruppen in privaten und beruflichen Kontexten wird durch webbasierte Soziale Netzwerke (Social Networks) wie Myspace, Linkedin und Flickr gefördert. Zahlreiche Personen nutzen zudem so genannte Social Software wie Skype, Del.icio.us, YouTube oder den aktuellen Newcomer twitter. Entsprechende Anwendungen werden durch moderne Informationsund Kommunikationstechnologien (IKT), zumeist durch Internettechnologien, realisiert und ermöglichen es den Nutzern, entweder neue Inhalte zu erstellen, und diese dann mit ausgewählten Personen (oder auch mit der Öffentlichkeit) zu teilen, oder sie dienen dazu, Verbindungen mit bestehenden Kontakten abzubilden sowie Neue aufzubauen. Gleichzeitig ist für die meisten Menschen heutzutage der Gebrauch mobiler Endgeräte ein wesentlicher Bestandteil ihres alltäglichen Lebens. In Folge dessen wird in der Verbindung dieser beiden, zunächst separaten, Felder eine, wenn nicht gar die „Killer-Anwendung“ für mobile Dienstleistungen vermutet. Der vorliegende Beitrag hat das Ziel, Potentiale und Grenzen der weit reichenden Verbreitung von Social Software und Sozialen Netzwerken auf mobile Endgeräte zu analysieren.

Der Einsatz großer, vertikaler Displays nimmt sowohl in Bereichen der Forschung als auch der Wirtschaft zu. Diese Displays eignen sich durch ihre Größe und Auflösung unter anderem für die Informationsvisualisierung. Es gibt bereits eine Menge von Forschungsarbeiten, welche die Interaktion mit großen, vertikalen Displays untersucht hat. Jedoch ist speziell die Bedienung Magischer Linsen auf großen Displaywänden weitgehend unbeachtet geblieben. Eine intuitive Interaktion mit Magischen Linsen auf einer Displaywand kann jedoch insbesondere in kollaborativen Szenarien große Vorteile bieten. Smartphones eignen sich durch ihre Portabilität zur Interaktion mit Displaywänden. Unter Verwendung von Mobilgeräten und einer hochauflösenden Displaywand wurden im Rahmen der vorliegenden Arbeit Interaktionskonzepte zur Steuerung und Parametrisierung Magischer Linsen entwickelt. Hierzu wurde eine Recherche des aktuellen Forschungsstandes betrieben und Anwendungsfälle für den Einsatz der Konzepte aufgestellt. Es wurde eine große Bandbreite von Interaktionskonzepten entwickelt, welche von lockeren bis zu fokussierten Interaktionen reichen. Für die Bedienung der Magischen Linsen wurden verschiedene Aktionen identifiziert, welche in einem Interaktionsablauf auftreten und durch die Konzepte zu unterstützen sind. Ein Teil der entwickelten Interaktionskonzepte wurde durch einen Prototypen implementiert und anhand von Beispieldatensätzen getestet. / The usage of large, vertical displays is increasing in felds of research as well as in the economy. Because of their size and resolution these displays are well suited for information visualization. There already are a number of publications which examine the interaction with large, vertical displays. Yet especially the operation of magic lenses on large display walls has been mostly ignored. An intuitive interaction with magic lenses on a large display may be espesially advantageous in collaborative scenarios. Smartphones are suited for interaction with display walls because of their portability. In this paper interaction concepts for operating and parametrizing magic lenses have been developed using mobile devices and a high resolution display wall. For this purpose the current state of research has been investigated and application scenarios for the use of the concepts have been constructed. A big amount of interaction concepts have been developed which range from casual to focused interactions. For the operation of magic lenses several actions have been identifed which occur in an interaction process and have to be adsressed by the concepts. Part of the developed interaction concepts have been implemented by a prototype and tested with sample data sets.

There is growing evidence that knowledge co-creation and interactivity during learning interventions aid knowledge acquisition and knowledge transfer. However, learners have mostly been passive consumers and not co-creators of the knowledge visualisation aids created by teachers and instructional designers. As such, knowledge visualisation has been underutilised for allowing learners to construct, demonstrate and share what they have learned. The dearth of appropriate guidelines for the use of knowledge visualisation for teaching and learning is an obstacle to using knowledge visualisation in teaching and learning. This provides a rationale for this study, which aims to investigate usability-based knowledge visualisation guidelines for teaching and learning. The application context is that of Science teaching for high school learners in the Gauteng province of South Africa. Following a design-based research methodology, an artefact of usability-based knowledge visualisation guidelines was created. The artefact was evaluated by testing learners’ conformity to the visualisation guidelines. Qualitative and quantitative data was captured using questionnaires, interviews and observations. The findings indicate that the guidelines considered in this study had various degrees of impact on the visualisations produced by learners. While some made noticeable impact, for others it could be considered negligible. Within the context of high school learning, these results justify the prioritisation of usability-based knowledge visualisation guidelines. Integrating Human Computer Interaction usability principles and knowledge visualisation guidelines to create usability-based knowledge visualisation guidelines provide a novel theoretical contribution upon which scientific knowledge visualisation can be expanded. / School of Computing / M. Sc. (Computing)

Die Internetzugriffe über Smartphones steigen jährlich und erreichten im Jahre 2017 eine weltweite Quote von über 50% (StatCounter, 2018). Da die Mehrzahl der Google-Nutzenden von mobilen Endgeräten aus zugreift, indiziert Google seit März 2018 bei Webseiten, die mit dem „mobile-first“-Ansatz erstellt wurden, die mobile Version und nicht mehr wie zuvor in erster Linie die Desktop-Variante (Google, 2018). Bereits diese beiden Umstände verdeutlichen eindrücklich, wie wichtig es ist, Interfaces jeglicher Art für mobile Endgeräte zu optimieren, beziehungsweise erst für mobile Geräte zu entwickeln und diese im Anschluss für größere Bildschirme zu verbessern. Revilla et al. (2014) untersuchten im Jahr 2014 eine Reihe von Umfragen, die in Spanien, Portugal und Südamerika durchgeführt wurden. Sie stellten fest, dass der Großteil der Teilnehmenden, obwohl mehrere Geräte zur Durchführung der Umfrage zur Verfügung standen (z. B. PC und Smartphone), insbesondere das Smartphone für die Beantwortung wählte (Revilla et al., 2014). Tatsächlich werden Online-Fragebogen schon seit einigen Jahren nicht mehr ausschließlich auf Desktop-Computern bearbeitet (Callegaro, 2010). Es zeigt sich vielmehr eine Tendenz zur vermehrten Nutzung mobiler Geräte. Im Jahre 2011 konnten lediglich 4% Smartphone-Teilnehmende verzeichnet werden, im Jahre 2014 waren es hingegen bereits 18% (Sarraf et al., 2014) und in einer aktuellen Studie aus dem Jahr 2018 sogar 33,7% (Nissen & Janneck, 2018b). In diesem Beitrag gehen wir der Frage nach, welche Ergebnisse ein mobil eingesetztes Standard-Layout hinsichtlich der Abbruchquote, der Bearbeitungszeit, des Antwortverhaltens und der User Experience erzielt und ob sich diese Werte mit einem explizit für den mobilen Einsatz entwickelten Layout verbessern lassen. [... aus der Einleitung]

Traditional architectures of software systems are in heterogenous environment of today's computer networks too heavy-footed. One of principles, which tries to solve this problem is service-oriented architecture (SOA). Practical way of its implementation is represented by web services (WS) built upon protocols like SOAP or XML-RPC. This diploma thesis focuses problem of providing contextual information to mobile devices and its solution based on SOA principles. The thesis introduces design and implementation of web service providing contextual information to mobile devices and prototype of modular inverse SOAP proxy server allowing its effective monitoring and management.

[pt] O presente estudo tem o propósito de compreender os antecedentes da adoção de tecnologias de informação e comunicação (TIC), especificamente afetas a dispositivos móveis eletrônicos no contexto de sua aplicação na prestação de serviços públicos ao cidadão e o seu relacionamento com o Estado. Para tanto, a pesquisa buscou desenvolver um modelo inédito de adoção de inovações baseandose no Modelo de Difusão de Inovações (Rogers,2003), agregando a ele construtos adaptados ao contexto da relação do cidadão com governo brasileiro. A partir da teoria, são formuladas hipóteses que exploram quais fatores são capazes de impactar a atitude geral de adoção dos cidadãos em relação a tecnologias de governo móvel. O modelo proposto foi submetido a uma survey transversal, cuja amostra foi escolhida por conveniência, resultando em 666 registros válidos para análise. Os dados obtidos, analisados por meio da modelagem de equações estruturais, confirmam a maior parte das hipóteses formuladas e apresentam relações significativas entre os construtos vantagem relativa, compatibilidade, complexidade, conveniência, qualidade de serviço, confiança no governo e intenção de adoção na atitude geral de adoção sugerindo que o modelo proposto representa um avanço na compreensão dos fatores que influenciam a atitude geral de adoção do cidadão em relação a tecnologias de m-government. / [en] This study aims to understand the information and communication technologies (ICT) adoption background, specifically related to electronic mobile devices in the context of their application in the provision of public services to Brazilian citizens and their relationship with the State. To this end, the research sought to develop an unprecedented model of adopting innovations based on the Innovation Diffusion Model (Rogers, 2003), adding constructs adapted to the context of the citizen s relationship with the Brazilian government. Based on the theory, hypotheses that explore which factors are capable of impacting the general attitude of adoption were formulated. The proposed model, was subjected to a cross-sectional survey, resulting in 666 valid records from a convenience sample. The data obtained were analyzed using structural equation modeling (SEM). They confirm most of the hypotheses formulated and present significant relationships between the constructs relative advantage, compatibility, complexity, convenience, quality of service, trust in the government and intention to adopt in the general attitude of adoption, suggesting that the proposed model represents an advance in understanding the factors that influence the Brazilian citizen general attitude of adoption related to m-government.

Today’s most widely used tracking solutions for consumers involve the Global Positioning System (GPS) which meets most needs when it comes to rough estimation of location. GPS however is limited in accuracy with a horizontal error of around 5 meters and cannot be used in the areas where the satellites cannot provide a strong enough signal e.g. indoor areas or near mountains and other sources of blockage. Ultra-wideband (UWB) abolishes these two issues, providing an accuracy at centimeter level and works great in indoor areas. This thesis dives into the theory behind tracking devices with UWB and includes an implementation of the tracking as well as covers noteworthy issues, shortcomings, and future work. The app that is developed within this thesis runs on Android mobile devices and can locate and track another Android mobile device running the same app. Results were clear that the concept works, but more filtering needs to be done in order to remove the remaining noise.