Path finding on a spherical self-organizing map using distance transformations

Spatialization methods create visualizations that allow users to analyze high-dimensional data in an intuitive manner and facilitates the extraction of meaningful information. Just as geographic maps are simpli ed representations of geographic spaces, these visualizations are esssentially maps of abstract data spaces that are created through dimensionality reduction. While we are familiar with geographic maps for path planning/ nding applications, research into using maps of high-dimensional spaces for such purposes has been largely ignored. However, literature has shown that it is possible to use these maps to track temporal and state changes within a high-dimensional space. A popular dimensionality reduction method that produces a mapping for these purposes is the Self-Organizing Map. By using its topology preserving capabilities with a colour-based visualization method known as the U-Matrix, state transitions can be visualized as trajectories on the resulting mapping. Through these trajectories, one can gather information on the transition path between two points in the original high-dimensional state space. This raises the interesting question of whether or not the Self-Organizing Map can be used to discover the transition path between two points in an n-dimensional space. In this thesis, we use a spherically structured Self-Organizing Map called the Geodesic Self-Organizing Map for dimensionality reduction and the creation of a topological mapping that approximates the n-dimensional space. We rst present an intuitive method for a user to navigate the surface of the Geodesic SOM. A new application of the distance transformation algorithm is then proposed to compute the path between two points on the surface of the SOM, which corresponds to two points in the data space. Discussions will then follow on how this application could be improved using some form of surface shape analysis. The new approach presented in this thesis would then be evaluated by analyzing the results of using the Geodesic SOM for manifold embedding and by carrying out data analyses using carbon dioxide emissions data

Path finding on a spherical self-organizing map using distance transformations

Spatialization methods create visualizations that allow users to analyze high-dimensional data in an intuitive manner and facilitates the extraction of meaningful information. Just as geographic maps are simpli ed representations of geographic spaces, these visualizations are esssentially maps of abstract data spaces that are created through dimensionality reduction. While we are familiar with geographic maps for path planning/ nding applications, research into using maps of high-dimensional spaces for such purposes has been largely ignored. However, literature has shown that it is possible to use these maps to track temporal and state changes within a high-dimensional space. A popular dimensionality reduction method that produces a mapping for these purposes is the Self-Organizing Map. By using its topology preserving capabilities with a colour-based visualization method known as the U-Matrix, state transitions can be visualized as trajectories on the resulting mapping. Through these trajectories, one can gather information on the transition path between two points in the original high-dimensional state space. This raises the interesting question of whether or not the Self-Organizing Map can be used to discover the transition path between two points in an n-dimensional space. In this thesis, we use a spherically structured Self-Organizing Map called the Geodesic Self-Organizing Map for dimensionality reduction and the creation of a topological mapping that approximates the n-dimensional space. We rst present an intuitive method for a user to navigate the surface of the Geodesic SOM. A new application of the distance transformation algorithm is then proposed to compute the path between two points on the surface of the SOM, which corresponds to two points in the data space. Discussions will then follow on how this application could be improved using some form of surface shape analysis. The new approach presented in this thesis would then be evaluated by analyzing the results of using the Geodesic SOM for manifold embedding and by carrying out data analyses using carbon dioxide emissions data

VisualBib: A novel Web app for supporting researchers in the creation, visualization and sharing of bibliographies

In this paper, we present VisualBib, a Web application, which allows users to create, visualize, modify, explore, and share bibliographies and the related citation networks, using innovative diagrams, called narrative views. The metadata are retrieved in real-time from four existing bibliographic indexes, Scopus, OpenCitations, and CrossRef/Orcid. Bibliographies and views are formally described and modeled using zz-structures, a semantic, not-hierarchical data model. VisualBib has been evaluated through two evaluation studies, one focused on the quantitative side and another on the qualitative side. Taking into account both studies, they evaluate the tool regarding the effectiveness performing tasks, usability, graphic layout and other questions specific to the VisualBib features. The evaluation throws positive significant results in all areas when compared to Scopus searching features

Micro Visualizations: Design and Analysis of Visualizations for Small Display Spaces

The topic of this habilitation is the study of very small data visualizations, micro visualizations, in display contexts that can only dedicate minimal rendering space for data representations. For several years, together with my collaborators, I have been studying human perception, interaction, and analysis with micro visualizations in multiple contexts. In this document I bring together three of my research streams related to micro visualizations: data glyphs, where my joint research focused on studying the perception of small-multiple micro visualizations, word-scale visualizations, where my joint research focused on small visualizations embedded in text-documents, and small mobile data visualizations for smartwatches or fitness trackers. I consider these types of small visualizations together under the umbrella term ``micro visualizations.'' Micro visualizations are useful in multiple visualization contexts and I have been working towards a better understanding of the complexities involved in designing and using micro visualizations. Here, I define the term micro visualization, summarize my own and other past research and design guidelines and outline several design spaces for different types of micro visualizations based on some of the work I was involved in since my PhD.Le sujet de cette habilitation est l'étude de très petites visualisations de données, les micro visualisations, dans des contextes d'affichage qui ne peuvent consacrer qu'un espace de rendu minimal aux représentations de données. Depuis plusieurs années, avec mes collaborateurs, j'étudie la perception humaine, l'interaction et l'analyse conduite avec des micro visualisations dans de multiples contextes.Dans ce document, je rassemble trois de mes axes de recherche liés aux micro visualisations~: les glyphes de données, où ma recherche s'est concentrée sur l'étude de la perception de micro visualisations dans un context \textit{small-multiple}, les \textit{word-scale visualizations}, où ma recherche s'est concentrée sur les petites visualisations intégrées dans les documents textuels, et les petites visualisations de données mobiles pour les montres connectées. Je considère ces types de petites visualisations sous le terme générique de ``micro visualisations.'' Les micro visualisations sont utiles dans de multiples contextes de visualisation et j'ai travaillé à une meilleure compréhension de la complexité des conceptions et utilisations des micro visualisations. Je définirai ici le terme de micro visualisation, je résumerai mes propres recherches et celles d'autres chercheurs, ainsi que les directives de conception, et j'esquisserai plusieurs espaces de conception pour différents types de micro visualisations, sur la base de certains des travaux auxquels j'ai participé depuis mon doctorat

Using mobile information visualisation to support the analysis of telecommunication service ultilisation

Telecommunication service utilisation (TSU) focuses on how customers make use of telecommunication services and can provide valuable information for decision making for improved customer service delivery. When a telecommunication service provider consults with customers, large amounts of static documentation on TSU data are compiled. Compiling this documentation for in-field investigation is manually intensive and the documentation does not effectively support decision making. Existing systems for visualising TSU data do not efficiently support in-field investigation of TSU and lack dynamic interaction. This highlights the need to investigate a solution to better support in-field investigation of TSU. This research followed a Design Science Research methodology to develop and evaluate a solution to solve the problem identified. The use of tablet devices for in-field investigation of TSU was identified as a suitable solution. Mobile information visualisation (MIV) techniques were investigated to determine appropriate display and interaction techniques for the visualisation of TSU data on a tablet device. An existing visualisation framework for TSU was identified and extended to incorporate touch-based interactions. Three service usage views were identified for visualising TSU, namely a Trend, Network and Detail Usage View. A Dashboard View was also identified to provide a quick reference view of the different views. A prototype called MobiTel was developed on a tablet device. MobiTel incorporated the identified information visualisation techniques. MobiTel was evaluated using an expert review and a user study to determine its usability and usefulness. The results indicated that MobiTel was perceived as being useful for in-field investigation and that the participants perceived the prototype to be easy to use and learn. The user study also indicated that the participants were satisfied with MobiTel. This research has determined that MIV techniques can be used for in-field investigation of TSU. Design recommendations were devised for designing an interactive mobile prototype for visualising service usage information. Future work will involve using map-based visualisation for visualising TSU data on different customer sites

Visual approaches to knowledge organization and contextual exploration

This thesis explores possible visual approaches for the representation of semantic structures, such as zz-structures. Some holistic visual representations of complex domains have been investigated through the proposal of new views - the so-called zz-views - that allow both to make visible the interconnections between elements and to support a contextual and multilevel exploration of knowledge. The potential of this approach has been examined in the context of two case studies that have led to the creation of two Web applications. The \ufb01rst domain of study regarded the visual representation, analysis and management of scienti\ufb01c bibliographies. In this context, we modeled a Web application, we called VisualBib, to support researchers in building, re\ufb01ning, analyzing and sharing bibliographies. We adopted a multi-faceted approach integrating features that are typical of three di\ufb00erent classes of tools: bibliography visual analysis systems, bibliographic citation indexes and personal research assistants. The evaluation studies carried out on a \ufb01rst prototype highlighted the positive impact of our visual model and encouraged us to improve it and develop further visual analysis features we incorporated in the version 3.0 of the application. The second case study concerned the modeling and development of a multimedia catalog of Web and mobile applications. The objective was to provide an overview of a significant number of tools that can help teachers in the implementation of active learning approaches supported by technology and in the design of Teaching and Learning Activities (TLAs). We analyzed and documented 281 applications, preparing for each of them a detailed multilingual card and a video-presentation, organizing all the material in an original purpose-based taxonomy, visually represented through a browsable holistic view. The catalog, we called AppInventory, provides contextual exploration mechanisms based on zz-structures, collects user contributions and evaluations about the apps and o\ufb00ers visual analysis tools for the comparison of the applications data and user evaluations. The results of two user studies carried out on groups of teachers and students shown a very positive impact of our proposal in term of graphical layout, semantic structure, navigation mechanisms and usability, also in comparison with two similar catalogs

Visualizing Set Relations and Cardinalities Using Venn and Euler Diagrams

In medicine, genetics, criminology and various other areas, Venn and Euler diagrams are used to visualize data set relations and their cardinalities. The data sets are represented by closed curves and the data set relationships are depicted by the overlaps between these curves. Both the sets and their intersections are easily visible as the closed curves are preattentively processed and form common regions that have a strong perceptual grouping effect. Besides set relations such as intersection, containment and disjointness, the cardinality of the sets and their intersections can also be depicted in the same diagram (referred to as area-proportional) through the size of the curves and their overlaps. Size is a preattentive feature and so similarities, differences and trends are easily identified. Thus, such diagrams facilitate data analysis and reasoning about the sets. However, drawing these diagrams manually is difficult, often impossible, and current automatic drawing methods do not always produce appropriate diagrams. This dissertation presents novel automatic drawing methods for different types of Euler diagrams and a user study of how such diagrams can help probabilistic judgement. The main drawing algorithms are: eulerForce, which uses a force-directed approach to lay out Euler diagrams; eulerAPE, which draws area-proportional Venn diagrams with ellipses. The user study evaluated the effectiveness of area- proportional Euler diagrams, glyph representations, Euler diagrams with glyphs and text+visualization formats for Bayesian reasoning, and a method eulerGlyphs was devised to automatically and accurately draw the assessed visualizations for any Bayesian problem. Additionally, analytic algorithms that instantaneously compute the overlapping areas of three general intersecting ellipses are provided, together with an evaluation of the effectiveness of ellipses in drawing accurate area-proportional Venn diagrams for 3-set data and the characteristics of the data that can be depicted accurately with ellipses

ICS Materials. Towards a re-Interpretation of material qualities through interactive, connected, and smart materials.

The domain of materials for design is changing under the influence of an increased technological advancement, miniaturization and democratization. Materials are becoming connected, augmented, computational, interactive, active, responsive, and dynamic. These are ICS Materials, an acronym that stands for Interactive, Connected and Smart. While labs around the world are experimenting with these new materials, there is the need to reflect on their potentials and impact on design. This paper is a first step in this direction: to interpret and describe the qualities of ICS materials, considering their experiential pattern, their expressive sensorial dimension, and their aesthetic of interaction. Through case studies, we analyse and classify these emerging ICS Materials and identified common characteristics, and challenges, e.g. the ability to change over time or their programmability by the designers and users. On that basis, we argue there is the need to reframe and redesign existing models to describe ICS materials, making their qualities emerge

Retrieval Methods for Historic Corpora in non-standard Spelling

Die Anzahl von digitalen Bibliotheken, die auch historische Volltexte enthalten, steigt immer weiter. Damit einhergehend wächst auch die Anzahl an digital verfügbaren historischen Dokumenten. Trotzdem gestaltet sich die Suche nach diesen Dokumenten immer noch schwierig. Aufgrund fehlender Standardisierung der Rechtschreibung ist es vielfach nicht möglich, mit Suchbegriffen in heutiger Sprache historische Texte zu finden. Diese Thematik ist vor allem bei Sprachen relevant, deren Rechtschreibung erst spät standardisiert wurde, wie z. B. Deutsch und Englisch. In dieser Arbeit wird ein neuer Ansatz für Retrieval in Texten mit nicht standardisierter Rechtschreibung entwickelt. Es wird ein Algorithmus beschrieben, der den Benutzer bei der Suche in digitalen Bibliotheken unterstützt. Basierend auf Belegpaaren aus aktueller und historischer Schreibung generiert der Algorithmus probabilistische Regeln. Mit diesen werden Varianten eines Suchbegriffes in historischer Schreibung generiert. Dargestellt wird die Gesamtarchitektur der Suchmaschine einschließlich der Evaluierung. Ausgehend von einem Suchbegriff in Grundform wird ein aktuelles deutsches Wörterbuch benutzt, um die zugehörigen Vollformen zu finden. Auf die gefundenen Vollformen werden die generierten Transformationsregeln angewendet, um die historischen Wortformen zu bilden. Die Experimente zeigen, dass sich die Retrievalqualität von historischen Kollektionen durch den vorgestellten Ansatz stark verbessert. Somit kann er den Benutzer in seiner täglichen Arbeit deutlich entlasten. Eine sehr große Anzahl historischer Dokumente, die bisher trotz ihrer Digitalisierung nicht sinnvoll durchsucht werden konnten, werden nun verschiedensten Benutzergruppen --- vom Laien bis zum Historiker --- besser zugänglich. Mit Hilfe des im Anschluss entwickelten Verfahrens zur automatischen Erstellung der Belege ist es zusätzlich möglich, den Engpass bei der Regelerstellung aufzulösen. Das Verfahren wurde in den entwickelten RuleGenerator integriert. Dieser stellt eine Benutzeroberfläche zur Verfügung, die dem Anwender die Generierung und Bearbeitung von Belegen und Regeln ermöglicht.The number of digital historical collections is continually growing. But even though full text is available, many documents can not be found because they are using a non-standard spelling. Most users will enter search terms in their contemporary language which differs from the historic language in the documents. This topic is most notably relevant for languages that have been standardised late, e. g. German and English. This thesis presents a new approach for retrieval of texts with non-standard spelling. For this purpose a new algorithm is described in order to support the user when searching in digital libraries. Based on evidences in contemporary and historical spelling the algorithm is generating probabilistic rules. These are used to generate historic variants of the search term. The overall architecture of the system including the evaluation is described. Given a search term as a lemma, a dictionary of contemporary German is used for finding all inflected and derived forms of the lemma. Then transformation rules (derived from training data) are applied in order to generate the historic spelling variants. The experimental results show that the retrieval quality for historic collections could be improved substantially. Thus the user can considerably be relieved in his daily work. Many historic documents could not be searched appropriately until now, even though they have been digitized. Hence they are much better accessible to different user groups ---­ from the linguist to the historian. The afterwards developed approach for automatically accepted evidences solves the bottleneck within the rule development process. The method has been integrated into the RuleGenerator an interactive tool for collecting evidences and a user driven rule generation process where the user can also modify generated rules and create rules on his own