The thesis deals with the possibilities of visualization of multivariate statistical data. Since this is a very broad area the thesis is divided into four sections, two of which are theoretically and two practically oriented. The first section is devoted to theoretical aspects of data visualization. It contains information about the building blocks of graphs, and how the brain processes graphs in various stages of perception. The second section charts the available chart types that can be used to display data. Selected types of graphs for continuous and discontinuous multidimensional data are described in detail. The third section focuses on available software tools for creating graphs. The section describes several programs, with focus on STATISTICA, R and MS Excel. The knowledge gained in previous chapters was sufficient source of information to perform a graphical analysis of multidimensional continuous and discrete data and using advanced analytical methods in the last section. This analysis is performed separately on the data file with continuous variables and on a data file with discontinuous (categorical) variables.

<p> In the history of scientific visualization techniques there is a lack of social science practices and methodologies. The advent of modern computer graphics brought the use of visualizations into a whole new era, but even though the tools by which such modern visualizations are created become easier to access and use, the lack of social science researchers harvesting the benefits of such tools still remain. This ease of use, increase in power and accessibility plus the ever growing need within the natural sciences to augment the human senses has further complicated the relationship between scientific methodologies, validity, reliability and the use of visualization techniques. This relationship must be explored, demystified and understood in order to fully grasp the impact of visualization practices when incorporated into any given scientific method. Within the social sciences there is one example of a tradition that has since its conception carried within it a graphical notion and a visualization practice. Time geography, a theory/method from the field of human/cultural geography has at its core a set of visualization techniques that encapsulate the very framework of time geographical analysis. Since it has been an integral part of the method trough out its history, it provides the perfect example for the study of the relationship between graphical visualization techniques and methodological development. The essay uses time geography as a case to construct and try out a set of scientific and methodological perspectives on the use of modern visualization techniques in social science practices. It is not an attempt to critically deconstruct this relationship within time geography, rather it points to a possible approach to the study of visualization techniques and their impact/role in the development of social science practices.</p> / <p>Den vetenskapliga visualiserings historia visar en tydlig brist på exempel från samhällsvetenskapliga praktiker och metoder. Den moderna datorgrafikens utveckling har tagit den vetenskapliga visualiseringen till nya nivåer, men trots att verktygen för skapandet av moderna datorgrafiska visualiseringar blivit lättare att hantera och förfoga över lyser de samhällsvetenskapliga exemplen på adopterandet av dessa verktyg fortfarande med sin frånvaro. Vertygens ökande grad av användarvänlighet och kraft, samt de naturvetenskapliga traditionernas ständigt växande behov att gå bortom de mänskliga sinnenas begränsningar har gjort relationen mellan visualiseringstekniker och vetenskapliga metoder, dess reliabilitet och validitet ytterligare komplicerad. För atttill fullo förstå hur inkorporerandet av visuella praktiker och modeller påverkar en metods utveckling i övrigt måste denna relation utforskas och analyseras. Inom samhällsvetenskapen finns en tradition som sedan sin tillkomst burit med sig ett visuellt språk och en visualiseringspraktik. Tidsgeografin, en delvis kulturgeografisk tradition har i själva sitt kärnspråk en serie viusaliseringsmodeller vilka är central del av metodens analysverktyg. Tidsgeografin erbjuder därmed ett utmärkt exempel för studier av relationen mellan vetenskapliga visualiseringspraktiker och metodologisk utveckling. Uppsatsen använder tidsgeografins metod och historia som en fallstudie i ett försök att konstruera och pröva ett antal vetenskapsteoretiska och metodologiska perspektiv på användandet av vetenskaplig visualisering inom samhällsvetenskapen. Uppsatsen är inte ett försök att kritiskt dekonstruera tidsgeografin, snarare visar den på en möjlig väg att närma sig studiet av moderna visualiseringsteknikers påverkan/roll i samhällsvetenskaplig metodutveckling.</p>

<p>Although we live in a society abundant with images, the subject of illustrations in scientific communication seems to have become a blind spot. The study of scientific communication is an interdisciplinary field, where written and visual language is studied separately from one another. The aim of this master thesis is to break with tradition and look at the use of illustrations, their form and frequency, in a random selection of Swedish contemporary doctoral theses to make an attempt to explain why some scholars do not use illustrations as much as others. The found graphics are discussed in their faculty and departmental context, and the aspects of page design, electronic availability, and publishing tradition are also included in this discussion. By looking at some activities surrounding the author of a doctoral thesis, such as writers’s manuals, computer graphic tools, and the role of librarians, proof was found to support a genre and activity theory, as described by Charles Bazerman. This study presents an overview of illustrations occurring in dissertations in a way that was not done before, opening up for further studies about the form and function of scientific illustrations as important carriers of information.</p> / <p>Fastän vi lever i ett samhälle som är översvämmat av bilder verkar vetenskapliga illustrationer vara ett ämne som förblivit ett slags blind punkt. Studierna av vetenskaplig kommunikation är ett interdisciplinärt område där det skrivna och visuella språket behandlas var för sig. Målet med denna D-uppsats är att bryta detta mönster och att undersöka bruket av illustrationer i en tillfälligt utvald samling svenska moderna avhandlingar för att se om det går att förklara varför en del forskare använder färre bilder än andra. De funna illustrationerna diskuteras i deras fakultets- och institutionssammanhang, och aspekterna sidutseende, elektronisk tillgång och utgivningssätt lyfts fram. Genom att titta på en del aktiviteter som omger författaren till en dissertation, som t.ex. skrivhandledningar, verktyg för datorgrafik och bibliotekariens roll, kunde bevis hittas för den genre- och aktivitetsteori som beskrivits av Charles Bazerman. Studien presenterar en översikt av förekommande illustrationer i doktorsavhandlingar som inte gjorts förut och öppnar vägen för nya studier om vetenskapliga bilders utseende och funktion som viktiga informationsbärare.</p>

Although we live in a society abundant with images, the subject of illustrations in scientific communication seems to have become a blind spot. The study of scientific communication is an interdisciplinary field, where written and visual language is studied separately from one another. The aim of this master thesis is to break with tradition and look at the use of illustrations, their form and frequency, in a random selection of Swedish contemporary doctoral theses to make an attempt to explain why some scholars do not use illustrations as much as others. The found graphics are discussed in their faculty and departmental context, and the aspects of page design, electronic availability, and publishing tradition are also included in this discussion. By looking at some activities surrounding the author of a doctoral thesis, such as writers’s manuals, computer graphic tools, and the role of librarians, proof was found to support a genre and activity theory, as described by Charles Bazerman. This study presents an overview of illustrations occurring in dissertations in a way that was not done before, opening up for further studies about the form and function of scientific illustrations as important carriers of information. / Fastän vi lever i ett samhälle som är översvämmat av bilder verkar vetenskapliga illustrationer vara ett ämne som förblivit ett slags blind punkt. Studierna av vetenskaplig kommunikation är ett interdisciplinärt område där det skrivna och visuella språket behandlas var för sig. Målet med denna D-uppsats är att bryta detta mönster och att undersöka bruket av illustrationer i en tillfälligt utvald samling svenska moderna avhandlingar för att se om det går att förklara varför en del forskare använder färre bilder än andra. De funna illustrationerna diskuteras i deras fakultets- och institutionssammanhang, och aspekterna sidutseende, elektronisk tillgång och utgivningssätt lyfts fram. Genom att titta på en del aktiviteter som omger författaren till en dissertation, som t.ex. skrivhandledningar, verktyg för datorgrafik och bibliotekariens roll, kunde bevis hittas för den genre- och aktivitetsteori som beskrivits av Charles Bazerman. Studien presenterar en översikt av förekommande illustrationer i doktorsavhandlingar som inte gjorts förut och öppnar vägen för nya studier om vetenskapliga bilders utseende och funktion som viktiga informationsbärare.

The Multi-Layer Perceptron (MLP) is one of the most widely applied and researched Artificial Neural Network model. MLP networks are normally applied to performing supervised learning tasks, which involve iterative training methods to adjust the connection weights within the network. This is commonly formulated as a multivariate non-linear optimization problem over a very high-dimensional space of possible weight configurations. Analogous to the field of mathematical optimization, training an MLP is often described as the search of an error surface for a weight vector which gives the smallest possible error value. Although this presents a useful notion of the training process, there are many problems associated with using the error surface to understand the behaviour of learning algorithms and the properties of MLP mappings themselves. Because of the high-dimensionality of the system, many existing methods of analysis are not well-suited to this problem. Visualizing and describing the error surface are also nontrivial and problematic. These problems are specific to complex systems such as neural networks, which contain large numbers of adjustable parameters, and the investigation of such systems in this way is largely a developing area of research. In this thesis, the concept of the error surface is explored using three related methods. Firstly, Principal Component Analysis (PCA) is proposed as a method for visualizing the learning trajectory followed by an algorithm on the error surface. It is found that PCA provides an effective method for performing such a visualization, as well as providing an indication of the significance of individual weights to the training process. Secondly, sampling methods are used to explore the error surface and to measure certain properties of the error surface, providing the necessary data for an intuitive description of the error surface. A number of practical MLP error surfaces are found to contain a high degree of ultrametric structure, in common with other known configuration spaces of complex systems. Thirdly, a class of global optimization algorithms is also developed, which is focused on the construction and evolution of a model of the error surface (or search spa ce) as an integral part of the optimization process. The relationships between this algorithm class, the Population-Based Incremental Learning algorithm, evolutionary algorithms and cooperative search are discussed. The work provides important practical techniques for exploration of the error surfaces of MLP networks. These techniques can be used to examine the dynamics of different training algorithms, the complexity of MLP mappings and an intuitive description of the nature of the error surface. The configuration spaces of other complex systems are also amenable to many of these techniques. Finally, the algorithmic framework provides a powerful paradigm for visualization of the optimization process and the development of parallel coupled optimization algorithms which apply knowledge of the error surface to solving the optimization problem.

Les architectures par composants sont de plus en plus étudiées et utilisées pour le développement efficace des applications en génie logiciel. Elles offrent, d’un côté, une architecture claire aux développeurs, et de l’autre, une séparation des différentes parties fonctionnelles et en particulier dans les applications de visualisation scientifique interactives. La modélisation de ces applications doit permettre la description des comportements de chaque composant et les actions globales du système. De plus, les interactions entre composants s’expriment par des schémas de communication qui peuvent être très complexes avec, par exemple, la possibilité de perdre des messages pour gagner en performance. Cette thèse décrit le modèle ComSA (Component-based approach for Scientific Applications) qui est basé sur une approche par composants dédiée aux applications de visualisation scientifique interactive et dynamique formalisée par les réseaux FIFO colorés stricts (sCFN). Les principales contributions de cette thèse sont dans un premier temps, un ensemble d’outils pour modéliser les différents comportements des composants ainsi que les différentes politiques de communication au sein de l’application. Dans un second temps, la définition de propriétés garantissant un démarrage propre de l’application en analysant et détectant les blocages. Cela permet de garantir la vivacité tout au long de l’exécution de l’application. Finalement l’étude de la reconfiguration dynamique des applications d’analyse visuelle par ajout ou suppression à la volée d’un composant sans arrêter toute l’application. Cette reconfiguration permet de minimiser le nombre de services non disponibles. / Component-based approaches are increasingly studied and used for the effective development of the applications in software engineering. They offer, on the one hand, safe architecture to developers, and on the other one, a separation of the various functional parts and particularly in the interactive scientific visualization applications. Modeling such applications enables the behavior description of each component and the global system’s actions. Moreover, the interactions between components are expressed through a communication schemes sometimes very complex with, for example, the possibility to lose messages to enhance performance. This thesis describes ComSA model (Component-based approach for Scientific Applications) that relies on a component-based approach dedicated to interactive and dynamic scientific visualization applications and its formalization in strict Colored FIFO Nets (sCFN). The main contributions of this thesis are, first, the definition of a set of tools to model the component’s behaviors and the various application communication policies. Second, providing some properties on the application to guarantee it starts properly. It is done by analyzing and detecting deadlocks. This ensures the liveness throughout the application execution. Finally, we present dynamic reconfiguration of visual analytics applications by adding or removing on the fly of a component without stopping the whole application. This reconfiguration minimizes the number of unavailable services.

In the history of scientific visualization techniques there is a lack of social science practices and methodologies. The advent of modern computer graphics brought the use of visualizations into a whole new era, but even though the tools by which such modern visualizations are created become easier to access and use, the lack of social science researchers harvesting the benefits of such tools still remain. This ease of use, increase in power and accessibility plus the ever growing need within the natural sciences to augment the human senses has further complicated the relationship between scientific methodologies, validity, reliability and the use of visualization techniques. This relationship must be explored, demystified and understood in order to fully grasp the impact of visualization practices when incorporated into any given scientific method. Within the social sciences there is one example of a tradition that has since its conception carried within it a graphical notion and a visualization practice. Time geography, a theory/method from the field of human/cultural geography has at its core a set of visualization techniques that encapsulate the very framework of time geographical analysis. Since it has been an integral part of the method trough out its history, it provides the perfect example for the study of the relationship between graphical visualization techniques and methodological development. The essay uses time geography as a case to construct and try out a set of scientific and methodological perspectives on the use of modern visualization techniques in social science practices. It is not an attempt to critically deconstruct this relationship within time geography, rather it points to a possible approach to the study of visualization techniques and their impact/role in the development of social science practices. / Den vetenskapliga visualiserings historia visar en tydlig brist på exempel från samhällsvetenskapliga praktiker och metoder. Den moderna datorgrafikens utveckling har tagit den vetenskapliga visualiseringen till nya nivåer, men trots att verktygen för skapandet av moderna datorgrafiska visualiseringar blivit lättare att hantera och förfoga över lyser de samhällsvetenskapliga exemplen på adopterandet av dessa verktyg fortfarande med sin frånvaro. Vertygens ökande grad av användarvänlighet och kraft, samt de naturvetenskapliga traditionernas ständigt växande behov att gå bortom de mänskliga sinnenas begränsningar har gjort relationen mellan visualiseringstekniker och vetenskapliga metoder, dess reliabilitet och validitet ytterligare komplicerad. För atttill fullo förstå hur inkorporerandet av visuella praktiker och modeller påverkar en metods utveckling i övrigt måste denna relation utforskas och analyseras. Inom samhällsvetenskapen finns en tradition som sedan sin tillkomst burit med sig ett visuellt språk och en visualiseringspraktik. Tidsgeografin, en delvis kulturgeografisk tradition har i själva sitt kärnspråk en serie viusaliseringsmodeller vilka är central del av metodens analysverktyg. Tidsgeografin erbjuder därmed ett utmärkt exempel för studier av relationen mellan vetenskapliga visualiseringspraktiker och metodologisk utveckling. Uppsatsen använder tidsgeografins metod och historia som en fallstudie i ett försök att konstruera och pröva ett antal vetenskapsteoretiska och metodologiska perspektiv på användandet av vetenskaplig visualisering inom samhällsvetenskapen. Uppsatsen är inte ett försök att kritiskt dekonstruera tidsgeografin, snarare visar den på en möjlig väg att närma sig studiet av moderna visualiseringsteknikers påverkan/roll i samhällsvetenskaplig metodutveckling.

[pt] Atualmente, as malhas de simulação do fluxo em reservatórios naturais de petróleo (RNPs) são modelos compostos por centenas de milhares de células hexaédricas, cada uma podendo ser decomposta em 12 triângulos, de modo que a visualização interativa dessas malhas, através das estações gráficas atuais, ainda não é factível. À medida que os computadores e as placas gráficas aumentam sua capacidade de processamento, as malhas de simulação também crescem. A solução para esse tipo de problema passa, normalmente, por técnicas de aceleração, dentre as quais está a multi-resolução (MR). Ocorre, entretanto, que os modelos de multi-resolução atualmente conhecidos não são aplicáveis às malhas de simulação de RNPs, devido aos requisitos específicos da área, tais como a preservação do modelo de células hexaédricas e a descontinuidade entre células. Na realidade, as técnicas de multi-resolução tendem a enfocar a Visualização Realista, enquanto o problema de RNPs é de Visualização Científica, para a qual ainda não existem soluções genéricas. Esta dissertação propõe um modelo de MR específico para o problema de visualização das malhas de simulação em RNPs, no qual a partição descontínua do espaço, a semântica baseada em células hexaédricas e as características de visualização do problema são pontos considerados. O modelo proposto permite uma construção eficiente da estrutura de MR, a partir da qual, em tempo real, são extraídas malhas adaptativas dependentes: (a) do erro geométrico da aproximação, (b) da câmera e (c) do número desejado de polígonos na malha. Além disso, o modelo permite a utilização conjunta de outra técnica de aceleração, o descarte, possibilitando o descarte hierárquico de regiões da malha que estão fora do volume de visão. O modelo proposto foi implementado em um sistema que permitiu uma extensa bateria de testes, cujos resultados permitiram traçar algumas conclusões e recomendações. / [en] Current flow-simulation meshes of natural oil reservoirs (NOR) are composed of hundreds of thousands of hexahedral cells. The visualization of the geometry of these cells superimposed with color attributes to represent properties and flow results requires the rendering of an unstructured mesh of millions of triangles. Current graphics hardware does not allow for an interactive visualization of such meshes. As computers and graphics boards increase their processing capacity, simulation meshes also grow and the solution to the rendering problem usually includes acceleration techniques, one of which is multi-resolution (MR). However, currently known MR models are not applicable to NOR simulation meshes due to this field`s specific requirements, such as the preservation of the hexahedral- cell model and discontinuities among cells. In fact, MR techniques tend to focus on Realistic Visualization, while the NOR problem is one of Scientific Visualization, for which generic solutions still do not exist. The present work proposes a specific MR model for the visualization problem concerning NOR simulation meshes, in which discontinuous space partition, hexahedral-cell-based semantics and the problem`s visualization characteristics are taken into account. The proposed model allows an efficient construction of a MR structure, from which, in real time, adaptive meshes can be extracted that depend on: (a) the geometric error approximation, (b) the view, and (c) the polygon budget. This model can also be used combined with another acceleration technique, frustum culling, which allows for the hierarchical elimination of regions in the mesh that are out of the view volume. The proposed model was implemented in a system on which extensive testing was performed, providing results that allowed us to draw some conclusions and recommendations.

The work described in this thesis is part of the Open Space project, a collaboration between Linköping University, NASA and the American Museum of Natural History. The long-term goal of Open Space is a multi-purpose, open-source scientific visualization software. The thesis covers the research and implementation of a pipeline for preparing and rendering volumetric data. The developed pipeline consists of three stages: A data formatting stage which takes data from various sources and prepares it for the rest of the pipeline, a pre-processing stage which builds a tree structure of of the raw data, and finally an interactive rendering stage which draws a volume using ray-casting. The pipeline is a fully working proof-of-concept for future development of Open Space, and can be used as-is to render space weather data using a combination of suitable data structures and an efficient data transfer pipeline. Many concepts and ideas from this work can be utilized in the larger-scale software project.

This thesis focuses on the design and implementation of a software system enabling out-of-core rendering of multiple map datasets mapped on virtual globes around our solar system. Challenges such as precision, accuracy, curvature and massive datasets were considered. The result is a globe visualization software using a chunked level of detail approach for rendering. The software can render texture layers of various sorts to aid in scientific visualization on top of height mapped geometry, yielding accurate visualizations rendered at interactive frame rates. The project was conducted at the American Museum of Natural History (AMNH), New York and serves the goal of implementing a planetary visualization software to aid in public presentations and bringing space science to the public. The work is part of the development of the software OpenSpace, which is the result of a collaboration between Linköping University, AMNH and the National Aeronautics and Space Administration (NASA) among others.