Signal processing is used in a wide variety of applications, ranging from digital image processing to biomedicine. Recently, some tools from signal processing have been extended to the context of graphs, allowing its use on irregular domains. Among others, the Fourier Transform and the Wavelet Transform have been adapted to such context. Graph signal processing (GSP) is a new field with many potential applications on data exploration. In this dissertation we show how tools from graph signal processing can be used for visual analysis. Specifically, we proposed a data filtering method, based on spectral graph filtering, that led to high quality visualizations which were attested qualitatively and quantitatively. On the other hand, we relied on the graph wavelet transform to enable the visual analysis of massive time-varying data revealing interesting phenomena and events. The proposed applications of GSP to visually analyze data are a first step towards incorporating the use of this theory into information visualization methods. Many possibilities from GSP can be explored by improving the understanding of static and time-varying phenomena that are yet to be uncovered. / O processamento de sinais é usado em uma ampla variedade de aplicações, desde o processamento digital de imagens até a biomedicina. Recentemente, algumas ferramentas do processamento de sinais foram estendidas ao contexto de grafos, permitindo seu uso em domínios irregulares. Entre outros, a Transformada de Fourier e a Transformada Wavelet foram adaptadas nesse contexto. O Processamento de Sinais em Grafos (PSG) é um novo campo com muitos aplicativos potenciais na exploração de dados. Nesta dissertação mostramos como ferramentas de processamento de sinal gráfico podem ser usadas para análise visual. Especificamente, o método de filtragem de dados porposto, baseado na filtragem de grafos espectrais, levou a visualizações de alta qualidade que foram atestadas qualitativa e quantitativamente. Por outro lado, usamos a transformada de wavelet em grafos para permitir a análise visual de dados massivos variantes no tempo, revelando fenômenos e eventos interessantes. As aplicações propostas do PSG para analisar visualmente os dados são um primeiro passo para incorporar o uso desta teoria nos métodos de visualização da informação. Muitas possibilidades do PSG podem ser exploradas melhorando a compreensão de fenômenos estáticos e variantes no tempo que ainda não foram descobertos.

The purpose of this project is to develop a Java Applet that provides all the tools needed for creating image fantasies. It lets the user pick a template and an image, and combine them together. The user can then apply image processing techniques such as rotation, zooming, blurring etc according to his/her requirements.

Public displays are increasingly used in public transport to present information such as departure and arrival times or network maps. Since this information is displayed generically, users often have problems to find the specific information they need. We propose context-aware visualizations on public displays to support passengers by improving personalized information access. Several visualizations for this domain were identified, for example, highlighting individual route or pricing information by fading out the background or increasing readability by font size adaptation. To investigate the influence of adapted content on the user we tested prototypical presentations that show personalized information concerning personal trips. In our user study with 20 participants we analyzed these visualizations to compare their efficiency in contrast to non-adaptive content by measuring time to perform specific tasks. This work presents the results of our user study. They show that especially highlighted information supports the user in finding personalized information faster.

With the continued development towards a digitalized and data-driven world, the importance of visual data analysis is increasing as well. Visual data analysis enables people to interactively explore and reason on certain data through the combined use of multiple visualizations. This is relevant for a wide range of application domains, including personal, professional, and public ones. In parallel, a ubiquity of modern devices with very heterogeneous characteristics has spawned. These devices, such as smartphones, tablets, or digital whiteboards, can enable more flexible workflows during our daily work, for example, while on-the-go, in meetings, or at home. One way to enable flexible workflows is the combination of multiple devices in so-called device ecologies. This thesis investigates how such a combined usage of devices can facilitate the visual data analysis of multivariate data sets. For that, new approaches for both visualization and interaction are presented here, allowing to make full use of the dynamic nature of device ecologies. So far, the literature on these aspects is limited and lacks a broader consideration of data analysis in device ecologies. This doctoral thesis presents investigations into three main parts, each addressing one research question: (i) how visualizations can be adapted for heterogeneous devices, (ii) how device pairings can be used to support data exploration workflows, and (iii) how visual data analysis can be supported in fully dynamic device ecologies. For the first part, an extended analytical investigation of the notion of responsive visualization is contributed. This investigation is then complemented by the introduction of a novel matrix-based visualization approach that incorporates such responsive visualizations as local focus regions. For the two other parts, multiple conceptual frameworks are presented that are innovative combinations of visualization and interaction techniques. In the second part, such work is conducted for two selected display pairings, the extension of smartwatches with display-equipped watchstraps and the contrary combination of smartwatch and large display. For these device ensembles, it is investigated how analysis workflows can be facilitated. Then, in the third part, it is explored how interactive mechanisms can be used for flexibly combining and coordinating devices by utilizing spatial arrangements, as well as how the view distribution process can be supported through automated optimization processes. This thesis’s extensive conceptual work is accompanied by the design of prototypical systems, qualitative evaluations, and reviews of existing literature.

Das stetig wachsende Datenaufkommen - die weltweite Datenmenge verdoppelt sich alle zwei Jahre - ist eine wesentliche Herausforderung für den Menschen in allen Bereichen des beruflichen und privaten Alltags. Um trotzdem relevante Informationen zu identifizieren und auch zu verstehen, nehmen Techniken und Anwendungen zur InfoVis einen immer größeren Stellenwert ein. Leider hat sich die Vision der "InfoVis for and by the masses" aufgrund des notwendigen Daten-, Visualisierungs- und Programmierwissens noch nicht durchgesetzt. Zudem sind heutige InfoVis-Softwareanbieter mit dem Problem konfrontiert, verschiedenste Kontexte, wie Nutzergruppen oder Hard- und Softwareplattformen, unterstützen zu müssen. Ein möglicher Lösungsansatz für dieses Problem ist das Paradigma der kompositen Webanwendungen. Auf deren Basis können Daten und UI-Widgets je nach Anwendungsfall teils automatisch kombiniert werden. Dies erhöht die Wiederverwendbarkeit und spart Zeit sowie Entwicklungskosten. Unter Zuhilfenahme von (semantischen) Modellen ist es zudem möglich, eine komposite RIA an die vorliegende Situation zu adaptieren. Um dem Endanwender Zugang zu den kompositen RIA zu verschaffen, mangelt es jedoch an einem Integrationsprozess, der den speziellen Anforderungen der InfoVis gerecht wird. Diese Dissertation stellt deshalb neue Konzepte für einen ganzheitlichen Semantik-gestützten InfoVis-Prozess vor, der bspw. die Endnutzer-gerechte Filterung großer Datensätze, die kontextsensitive Auswahl von InfoVis-Komponenten, die Nutzerunterstützung bei der Exploration und Interpretation der Daten sowie die Gewinnung und Wiederverwendung von Visualisierungswissen adressiert. Zur Unterstützung des InfoVis-Prozesses werden weiterhin Konzepte für eine formale Wissensbasis mit Domänenwissen vorgeschlagen. Die modulare, mit W3C-Standards prototypisch realisierte Visualisierungsontologie definiert u.a. Konzepte und Relationen zu Daten, graphischen Vokabular, menschlicher Aktivität sowie veränderliches Faktenwissen. Ein weiterer, wesentlicher Beitrag der Arbeit liegt in der Architekturkonzeption für modellbasierte, komposite RIA für die InfoVis-Domäne, womit ein neues Anwendungsfeld des Software-Paradigmas erschlossen wird. Damit steht nun erstmals für eine komposite, webbasierte InfoVis-Lösung ein ganzheitliches Architekturkonzept zur Verfügung, das die Ausführbarkeit der Anwendungen in der heute existierenden, heterogenen Landschaft der (mobilen) Endgeräte gewährleisten kann. Durch die Implementierung entscheidender Architekturkonzepte sowie einer beispielhaften InfoVis-Anwendung für semantische Daten wurde die Tragfähigkeit der geschaffenen Konzepte nachgewiesen. Anhand einer Vielzahl von formativen sowie einer summativen Nutzerstudien konnte validiert werden, dass sich aus den neuen Konzepten Vorteile für den Endanwender bei der Erstellung einer InfoVis ergeben.

Aus der Einführung: "Die Verwendung von Prototypen besitzt eine zentrale Rolle bei der Produktentwicklung und im Designprozess (Camere et al. 2016). Wie Camere und Bordegoni feststellen hat sich der Fokus der Designdisziplin auf Funktionalität um die Aspekte der Usability und der User Experience erweitert. Damit einhergehend hat sich auch die Rolle der Prototypen von Funktionsmustern und Präsentationsobjekten um die Funktionen als Evaluierungs- und Versuchsobjekte ergänzt. Die Integration von Nutzern in den Designprozess ist dabei ein weiterer Punkt bei denen Prototypen ein wichtiges Werkzeug zur Kommunikation und kooperativen Arbeit liefert (Schneider 1996). Die Integration von Prototyping-Methoden in den unterschiedlichen Phasen des Designprozesses führt zu unterschiedlichen Anforderungen hinsichtlich der Form und Aufgabe der Prototypen. Entsprechend vielfältig sind die heute verwendeten Arten von Prototyping. ..."

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)

Business simulation games are used in educational institutions and various industries in the private and public sector to train students and employees to practice the principles of management and decision-making skills by providing a fail-safe environment and enabling them to reflect on their simulation results. These games are generally advanced multiuser environments where a user, or a group of users, have access to a virtual company for making business decisions. Some of these games are expensive and their licences are time limited; typically, such a licence is only valid during the duration of the course. In general, these games are not available for the public as part of informal instructional courses. In Canada, teaching informal courses to immigrants and refugees, which involve data-driven decision making, to prepare them for future challenges they might encounter as business owners, can be challenging; especially considering language barriers and non-business-related backgrounds obtained outside of Canada. Furthermore, based on their decision-making styles, cognitive limitations, and past experiences, people may have an inaccurate perception of the problem or challenge they face, this could lead to poor decision making of the team they are part of and, therefore, this could reflect in the effectiveness of an organization as a whole. The objective of this research is to enrich current teaching tools in decision-making processes in entrepreneurship courses for newcomers in Canada with a comprehensive and visual representation of operational business problems involved in Business Intelligence and data analytics. More specifically, we designed and developed a 3D Business Simulation Game with randomized scenarios using modern technologies, such as Unreal Engine as the game engine; Adobe Fuse for the character creation, Mixamo for animation of the character, and Substance Painter for textures and materials for the assets. The research was conducted with the participation of the students of the Business Creation and Project Management course at VIRCS (Victoria Immigrant and Refugee Centre Society) where we tested this game on each one of the five units of the course. After designing, developing, and testing the 3D business simulation game, we conducted a comprehensive evaluation to investigate whether the decisions students made while playing were correct or not. We also evaluated whether they felt that the challenges were easier to understand, both as a team and individually, when they used the 3D business simulation game compared to only the written description of the problems. The main results we obtained from our study are the following: After playing the business simulation game, students became more aware of the importance of making correct decisions in different business scenarios. They made sure that the whole team understood the problem, and they felt generally good about their understanding of the course content. We also noticed that when the animation was not part of the business simulation game, they seemed to be confused when following written instructions. This indicate that they depended on the animations for their decision-making. We believe that, in some ways, the course and the 3D business simulation game we created for this research were a great opportunity to observe students becoming more confident in their future in Canada as entrepreneurs. We observed that, once the game has been used, the students become more participatory in class, the discussion of the course material increases, and in general, the students seem to enjoy the course more. / Graduate

Indiana University-Purdue University Indianapolis (IUPUI) / Healthcare data visualization presents challenges due to its non-standard organizational structure and disparate record formats. Epidemiologists and clinicians currently lack the tools to discern patterns in large-scale data that would reveal valuable healthcare information at the granular level of individual patients and populations. Integrating geospatial and temporal healthcare data within a common visual context provides a twofold benefit: it allows clinicians to synthesize large-scale healthcare data to provide a context for local patient care decisions, and it better informs epidemiologists in making public health recommendations. Advanced implementations of the Scalable Vector Graphic (SVG), HyperText Markup Language version 5 (HTML5), and Cascading Style Sheets version 3 (CSS3) specifications in the latest versions of most major Web browsers brought hardware-accelerated graphics to the Web and opened the door for more intricate and interactive visualization techniques than have previously been possible. We developed a series of new geotemporal visualization techniques under a general healthcare data visualization framework in order to provide a real-time dashboard for analysis and exploration of complex healthcare data. This visualization framework, HealthTerrain, is a concept space constructed using text and data mining techniques, extracted concepts, and attributes associated with geographical locations. HealthTerrain's association graph serves two purposes. First, it is a powerful interactive visualization of the relationships among concept terms, allowing users to explore the concept space, discover correlations, and generate novel hypotheses. Second, it functions as a user interface, allowing selection of concept terms for further visual analysis. In addition to the association graph, concept terms can be compared across time and location using several new visualization techniques. A spatial-temporal choropleth map projection embeds rich textures to generate an integrated, two-dimensional visualization. Its key feature is a new offset contour method to visualize multidimensional and time-series data associated with different geographical regions. Additionally, a ring graph reveals patterns at the fine granularity of patient occurrences using a new radial coordinate-based time-series visualization technique.