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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Uncertainty visualization of ensemble simulations

Sanyal, Jibonananda 09 December 2011 (has links)
Ensemble simulation is a commonly used technique in operational forecasting of weather and floods. Multi-member ensemble output is usually large, multivariate, and challenging to interpret interactively. Forecast meteorologists and hydrologists are interested in understanding the uncertainties associated with the simulation; specifically variability between the ensemble members. The visualization of ensemble members is currently accomplished through spaghetti plots or hydrographs. To improve visualization techniques and tools for forecasters, we conducted a userstudy to evaluate the effectiveness of existing uncertainty visualization techniques on 1D and 2D synthetic datasets. We designed an uncertainty evaluation framework to enable easier design of such studies for scientific visualization. The techniques evaluated are errorbars, scaled size of glyphs, color-mapping on glyphs, and color-mapping of uncertainty on the data surface. Although we did not find a consistent order among the four techniques for all tasks, we found that the efficiency of techniques used highly depended on the tasks being performed. Errorbars consistently underperformed throughout the experiment. Scaling the size of glyphs and color-mapping of the surface performed reasonably well. With results from the user-study, we iteratively developed a tool named ‘Noodles’ to interactively explore the ensemble uncertainty in weather simulations. Uncertainty was quantified using standard deviation, inter-quartile range, width of the 95% confidence interval, and by bootstrapping the data. A coordinated view of ribbon and glyph-based uncertainty visualization, spaghetti plots, and data transect plots was provided to two meteorologists for expert evaluation. They found it useful in assessing uncertainty in the data, especially in finding outliers and avoiding the parametrizations leading to these outliers. Additionally, they could identify spatial regions with high uncertainty thereby determining poorly simulated storm environments and deriving physical interpretation of these model issues. We also describe uncertainty visualization capabilities developed for a tool named ‘FloodViz’ for visualization and analysis of flood simulation ensembles. Simple member and trend plots and composited inundation maps with uncertainty are described along with different types of glyph based uncertainty representations. We also provide feedback from a hydrologist using various features of the tool from an operational perspective.
42

Development of Visual Tools for Analyzing Ensemble Error and Uncertainty

Anreddy, Sujan Ranjan Reddy 04 May 2018 (has links)
Climate analysts use Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations to make sense of models performance in predicting extreme events such as heavy precipitation. Similarly, weather analysts use numerical weather prediction models (NWP) to simulate weather conditions either by perturbing initial conditions or by changing multiple input parameterization schemes, e.g., cumulus and microphysics schemes. These simulations are used in operational weather forecasting and for studying the role of parameterization schemes in synoptic weather events like storms. This work addresses the need for visualizing the differences in both CMIP5 and NWP model output. This work proposes three glyph designs used for communicating CMIP5 model error. It also describes Ensemble Visual eXplorer tool that provides multiple ways of visualizing NWP model output and the related input parameter space. The proposed interactive dendrogram provides an effective way to relate multiple input parameterization schemes with spatial characteristics of model uncertainty features. The glyphs that were designed to communicate CMIP5 model error are extended to encode both parameterization schemes and graduated uncertainty, to provide related insights at specific locations such as storm center and the areas surrounding it. The work analyzes different ways of using glyphs to represent parametric uncertainty using visual variables such as color and size, in conjunction with Gestalt visual properties. It demonstrates the use of visual analytics in resolving some of the issues such as visual scalability. As part of this dissertation, we evaluated three glyph designs using average precipitation rate predicted by CMIP5 simulations, and Ensemble Visual eXplorer tool using WRF 1999 March 4th, North American storm track dataset.
43

Development of a geovisual analytics environment using parallel coordinates with applications to tropical cyclone trend analysis

Steed, Chad A 13 December 2008 (has links)
A global transformation is being fueled by unprecedented growth in the quality, quantity, and number of different parameters in environmental data through the convergence of several technological advances in data collection and modeling. Although these data hold great potential for helping us understand many complex and, in some cases, life-threatening environmental processes, our ability to generate such data is far outpacing our ability to analyze it. In particular, conventional environmental data analysis tools are inadequate for coping with the size and complexity of these data. As a result, users are forced to reduce the problem in order to adapt to the capabilities of the tools. To overcome these limitations, we must complement the power of computational methods with human knowledge, flexible thinking, imagination, and our capacity for insight by developing visual analysis tools that distill information into the actionable criteria needed for enhanced decision support. In light of said challenges, we have integrated automated statistical analysis capabilities with a highly interactive, multivariate visualization interface to produce a promising approach for visual environmental data analysis. By combining advanced interaction techniques such as dynamic axis scaling, conjunctive parallel coordinates, statistical indicators, and aerial perspective shading, we provide an enhanced variant of the classical parallel coordinates plot. Furthermore, the system facilitates statistical processes such as stepwise linear regression and correlation analysis to assist in the identification and quantification of the most significant predictors for a particular dependent variable. These capabilities are combined into a unique geovisual analytics system that is demonstrated via a pedagogical case study and three North Atlantic tropical cyclone climate studies using a systematic workflow. In addition to revealing several significant associations between environmental observations and tropical cyclone activity, this research corroborates the notion that enhanced parallel coordinates coupled with statistical analysis can be used for more effective knowledge discovery and confirmation in complex, real-world data sets.
44

Multi-Scale Cursor: Optimizing Mouse Interaction for Large Personal Workspaces

Dasiyici, Mehmet Celal 05 June 2008 (has links)
As increasingly large displays are integrated into personal workspaces, mouse-based interaction becomes more problematic. Users must repeatedly "clutch" the mouse for long distance movements [61]. The visibility of the cursor is also problematic in large screens, since the percentage of the screen space that the cursor takes from the whole display gets smaller. We test multi-scale approaches to mouse interaction that utilize dynamic speed and size techniques to grow the cursor larger and faster for long movements. Using Fitts' Law methods, we experimentally compare different implementations to optimize the mouse design for large displays and to test how they scale to large displays. We also compare them to techniques that integrate absolute pointing with head tracking. Results indicate that with some implementation level modifications the mouse device can scale well up to even a 100 megapixel display with lower mean movement times as compared to integrating absolute pointing techniques to mouse input while maintaining fast performance of the typical mouse configuration on small screens for short distance movements. Designs that have multiple acceleration levels and 4x maximum acceleration reduced average number of clutching to less than one per task in a 100 megapixel display. Dynamic size cursors statistically improve pointing performance. Results also indicated that dynamic speed transitions should be as smooth as possible without steps of more than 2x increase in speed. / Master of Science
45

Designing expressive interaction techniques for novices inspired by expert activities : the case of musical practice / La conception de techniques d’interaction expressives adaptées aux novices et inspirées par des activités expertes : le cas de la pratique musicale

Ghomi, Emilien 17 December 2012 (has links)
Les systèmes interactifs étant utilisés pour réaliser des tâches toujours plus complexes et variées, les utilisateurs ont besoin de systèmes qui soient à la fois expressifs, efficaces et utilisables. Si des systèmes simples peuvent être instantanément utilisables, l’expressivité accessible avec des systèmes complexes est souvent considérée comme réservée aux experts. Cependant, notre approche, inspirée par la recherche en phénoménologie et en psychologie, souligne que certaines activités expertes ayant une portée sociale, comme les activités artistiques, permettent aussi aux non-experts d’acquérir des compétences et une connaissance considérables de façon implicite. Dans ce manuscrit, nous évoquerons notamment la connaissance et les compétences avancées développées par les non-musiciens lors de l’écoute de la musique et de l’observation du jeu instrumental. Nous défendons deux idées. Premièrement, les concepteurs de systèmes interactifs peuvent profiter de ces compétences et de cette connaissance implicites pour créer des systèmes expressifs qui soient utilisables. Deuxièmement, les méthodes d'apprentissage expertes et les outils experts, qui ont été perfectionnés à travers le temps et ont fait leurs preuves dans des situations complexes, peuvent servir de sources d'inspiration pour améliorer l’utilisabilité des systèmes complexes pour les utilisateurs novices. Nous proposons un cadre de conception pour étudier l'utilisabilité et l'expressivité des techniques d'interaction, comme deux nouvelles mesures de la qualité de l'interaction, et présentons les trois projets de cette thèse. Dans le premier, nous étudions l'utilisation de motifs rythmiques pour l'interaction, et nous montrons que des utilisateurs novices sont capables de reproduire et de mémoriser efficacement de grands vocabulaires de motifs rythmiques. Une telle interaction tire parti des capacités naturelles des non-musiciens pour percevoir et reproduire des structures rythmiques. Nous définissons des règles pour créer des motifs rythmiques adaptés à l’interaction, et montrons qu’ils peuvent être utilisés efficacement pour déclencher des commandes. Dans le deuxième projet, nous étudions la conception et l’apprentissage de postures multi-doigt sur des écrans multi-tactiles. Nous prenons en compte les contraintes mécaniques et les degrés de liberté de la main pour créer des vocabulaires expressifs de postures multi-doigt, dont nous évaluons l’utilisabilité lors d’une expérimentation. Nous présentons une méthode d’apprentissage adaptée aux postures les plus complexes, inspirée par l’apprentissage des accords en musique, et nous montrons qu’elle peut améliorer la compréhension et la mémorisation. Dans le dernier projet, nous nous intéressons aux applications de création musicale en temps réel, et tentons de les faire profiter des qualités instrumentales des instruments acoustiques. Nous voulons créer des applications qui permettent un jeu virtuose et expressif, et dont les fonctionnalités élémentaires sont accessibles aux novices (comme on peut jouer quelques accords au piano sans apprentissage). Nous proposons un cadre de conception et une architecture logicielle qui aident à considérer la conception d’applications musicales comme une lutherie à part entière. Avec ces projets, nous montrons que, dans ces cas : (i) la connaissance et les compétences implicites des non-experts peuvent être réutilisées en interaction ; (ii) les méthodes d’apprentissage expertes peuvent permettre de rendre les systèmes expressifs plus utilisables ; (iii) s’inspirer des outils experts peut aider à concevoir des systèmes interactifs expressifs et utilisables. Nous proposons l’étude de l’utilisabilité comme une alternative à l’immédiateté prônée par les entreprises d’informatique, et nous présentons des méthodes pour tirer parti de la richesse des activités expertes et de la connaissance implicite des non-experts pour créer des systèmes interactifs expressifs et utilisables par les novices. / As interactive systems are now used to perform a variety of complex tasks, users need systems that are at the same time expressive, efficient and usable. Although simple interactive systems can be easily usable, interaction designers often consider that only expert practitioners can benefit from the expressiveness of more complex systems. Our approach, inspired by studies in phenomenology and psychology, underscores that non-experts have sizeable knowledge and advanced skills related to various expert activities having a social dimension –such as artistic activities–, which they gain implicitly through their engagement as perceivers. For example, we identify various music-related skills mastered by non-musicians, which they gain when listening to music or attending performances. We have two main arguments. First, interaction designers can reuse such implicit knowledge and skills to design interaction techniques that are both expressive and usable by novice users. Second, as expert artifacts and expert learning methods have evolved over time and have shown efficient to overcome the complexity of expert activities, they can be used as a source of inspiration to make expressive systems more easily usable by novice users. We provide a design framework for studying the usability and expressiveness of interaction techniques as two new aspects of the user experience, and explore this framework with three projects. In the first project we study the use of rhythmic patterns as an input method, and show that novice users are able to reproduce and memorize large vocabularies of patterns. This is made possible by the natural abilities of non-musicians to perceive, reproduce and make sense of rhythmic structures. We define a method to create expressive vocabularies of patterns, and show that novice users are able to efficiently use them as command triggers. In the second project, we study the design and learning of chording gestures on multitouch screens. We introduce design guidelines to create expressive chord vocabularies taking the mechanical constraints and the degrees of freedom of the human hand into account. We evaluate the usability of such gestures in an experiment and we present an adapted learning method inspired by the teaching of chords in music. We show that novice users are able to reproduce and memorize our vocabularies of chording gestures, while our learning method can improve long-term memorization. The final project focuses on music software used for live performances and proposes a framework for designing “instrumental” software allowing expert musical playing and having its elementary functionalities accessible to novices, as it is the case with acoustic instruments (for example, one can easily play a few chords on a piano without practice). We define a design framework inspired by a functional decomposition of acoustic instruments and present an adapted software architecture, both aiming to ease the design of such software and to make it match with instrument-making. These projects show that, in these cases: (i) the implicit knowledge novices have about some expert activities can be reused for interaction; (ii) expert learning methods can inspire ways to make expressive systems more usable novices; (iii) taking expert artifacts as a source of inspiration can help creating usable and expressive interactive systems. In this dissertation, we propose the study of usability as an alternative to the focus on immediacy that characterizes current commercial interactive systems. We also propose methods to benefit from the richness of expert activities and from the implicit knowledge of non-experts to design interactive systems that are at the same time expressive and usable by novice users.
46

A body-centric framework for generating and evaluating novel interaction techniques

Wagner, Julie 06 December 2012 (has links) (PDF)
This thesis introduces BodyScape, a body-centric framework that accounts for how users coordinate their movements within and across their own limbs in order to interact with a wide range of devices, across multiple surfaces. It introduces a graphical notation that describes interaction techniques in terms of (1) motor assemblies responsible for performing a control task (input motor assembly) or bringing the body into a position to visually perceive output (output motor assembly), and (2) the movement coordination of motor assemblies, relative to the body or fixed in the world, with respect to the interactive environment. This thesis applies BodyScape to 1) investigate the role of support in a set of novel bimanual interaction techniques for hand-held devices, 2) analyze the competing effect across multiple input movements, and 3) compare twelve pan-and-zoom techniques on a wall-sized display to determine the roles of guidance and interference on performance. Using BodyScape to characterize interaction clarifies the role of device support on the user's balance and subsequent comfort and performance. It allows designers to identify situations in which multiple body movements interfere with each other, with a corresponding decrease in performance. Finally, it highlights the trade-offs among different combinations of techniques, enabling the analysis and generation of a variety of multi-surface interaction techniques. I argue that including a body-centric perspective when defining interaction techniques is essential for addressing the combinatorial explosion of interactive devices in multi-surface environments.
47

Virtuell verklighet för kommunikation och interaktion : Interaktiva rum som kommunikationsverktyg

Fransson, Axel, Börjesson, Christoffer January 2017 (has links)
Kandidatarbetet undersöker virtuell verklighet som ett spatialt och interaktivt realtids-medium för den arkitekturella domänen. Media används vanligtvis inom mäklar-, visualiserings-, och designindustrin för att representera föremål på ett förståeligt och övertygande vis genom bilder eller animerade filmer. Utgångsproblemet har varit användbarheten av högdetaljerad arkitekturell visualisering som representeras i 2D. Studier visar att 2D passar för viss abstrakt information som kronologisk sekvens eller data trender, men för komplicerad information som lokalisering och spatiala relationer är 2D för abstrakt. Målet är att skapa en prototyp i form av ett virtuellt rum vars syfte tjänar kommunikationsverktyg mot intressenter eller inom organisationen för tydligare beslutsförmåga. Fokus låg på användbarhet för att evaluera prototypens design-aspekter navigation, selektion/manipulation och indirekta kontroller. Utgångspunkten var en pragmatisk filosofi med användningen av mixade metoder för att nå djupare insikter i prototypen. Med hjälp av texturerings-  och 3D modelleringsprogram samt spelmotorn Unreal Engine 4 har en virtuell nybyggnation skapats. Därefter har tre användbarhetstester formats som evalueras med hjälp av system usability scale. Detta expanderas på med en kvalitativ intervju där resonemang om användbarhet, kostnadseffektivitet och lämplighet framkommer. Utvärderingen indikerar att användarna är nöjda, men riktad evaluering av interaktions-teknikerna var för sig hade skapat insikter i specifika fallgropar av systemets designområden. / The bachelor thesis investigates virtual reality as a spatial and interactive real-time medium for the architectural domain. Media is usually used in the brokerage, visualization and design industry to represent objects in an understandable and compelling manner through images or animated films. The starting problem has been the usability of high-detailed architectural visualization represented in 2D. Studies show that 2D fits for some abstract information like chronological sequence or data trends, but for complex information such as location and spatial relationships, 2D is too abstract. The goal is to create a prototype in the form of a virtual space whose purpose serves as communication tools with stakeholders or within the organization for patent decision-making. The focus was on usability to evaluate the prototypes design aspects navigation, selection / manipulation, and indirect controls. A pragmatic philosophy was employed with the use of mixed methods to reach deeper insights into the prototype. With the help of texturing and 3D modeling programs and the Unreal Engine 4 game engine, a virtual room has been constructed. Thereafter, three usability tests were formatted and evaluated using system usability scale. This is expanded with a qualitative interview where reasoning about usability, cost-effectiveness and appropriateness emerges. The evaluation indicates that the users are satisfied, but targeted evaluation of the interaction techniques had created insights into specific pitfalls of the system's design areas.
48

Analyse du geste dansé et retours visuels par modèles physiques : apport des qualités de mouvement à l'interaction avec le corps entier / Dance Gesture Analysis and Visual Feedback based on Physical Models : Contributions of Movement Qualities in Whole Body Interaction

Fdili Alaoui, Sarah 19 December 2012 (has links)
La présente thèse a pour but d’approfondir l’étude du geste dans le cadre de l’interaction Homme Machine. Il s’agit de créer de nouveaux paradigmes d’interaction qui offrent à l’utilisateur de plus amples possibilités d’expression basées sur le geste. Un des vecteurs d’expression du geste, très rarement traité en Interaction Homme Machine, qui lui confère sa coloration et son aspect, est ce que les théoriciens et praticiens de la danse appellent « les qualités de mouvement ». Nous mettons à profit des collaborations avec le domaine de la danse pour étudier la notion de qualités de mouvement et l’intégrer à des paradigmes d’interaction gestuelle. Notre travail analyse les apports de l’intégration des qualités de mouvement comme modalité d’interaction, fournit les outils propices à l’élaboration de cette intégration (en termes de méthodes d’analyse, de visualisation et de contrôle gestuel), en développe et évalue certaines techniques d’interaction.Les contributions de la thèse se situent d’abord dans la formalisation de la notion de qualités de mouvement et l’évaluation de son intégration dans un dispositif interactif en termes d’expérience utilisateur. Sur le plan de la visualisation des qualités de mouvement, les travaux menés pendant la thèse ont permis de démontrer que les modèles physiques masses-ressorts offrent de grandes possibilités de simulation de comportements dynamiques et de contrôle en temps réel. Sur le plan de l’analyse, la thèse a permis de développer des approches novatrices de reconnaissance automatique des qualités de mouvement de l’utilisateur. Enfin, à partir des approches d’analyse et de visualisation des qualités de mouvement, la thèse a donné lieu à l’implémentation d’un ensemble de techniques d’interaction. Elle a appliqué et évalué ses techniques dans le contexte de la pédagogie de la danse et de la performance. / The thesis studies gesture in the context of Human-Computer interaction. It aims at creating new interaction paradigms that offer the user further expressive possibilities based on gestures. The theorists and practitioners of the dance call "movement qualities” (MQ), a notion that conveys expressive content describing the way a gesture is performed. This notion has been rarely taken into consideration in the field of HCI. Our work draws on collaborations with the field of dance to explore the notion of movement qualities and to integrate it as interaction modality. 

The contributions of the thesis are in the formalism of the notion of movement qualities and evaluation of its integration as interaction modality in terms of user experience. 

We also provide computational tools for considering MQ in interactive systems in terms of analysis, representation and gesture control methods. On the representational level, our work have demonstrated that physical models based on masses and springs systems offer great opportunities for simulating dynamics related to MQs and for real-time gesture control. On the analysis level, we developed innovative approaches to automatic real time recognition of movement qualities. Finally, we implemented of a set of interaction techniques based on movement qualities that we applied and evaluated in the context of dance pedagogy and performance.
49

A body-centric framework for generating and evaluating novel interaction techniques / Un espace de conception centré sur les fonctions corporelles pour la génération et l'évaluation de nouvelles techniques d'interaction

Wagner, Julie 06 December 2012 (has links)
Cette thèse présente BodyScape, un espace de conception prenant en compte l’engagement corporel de l’utilisateur dans l’interaction. BodyScape décrit la façon dont les utilisateurs coordonnent les mouvements de, et entre leurs membres, lorsqu’ils interagissent avec divers dispositifs d’entrée et entre plusieurs surfaces d’affichage. Il introduit une notation graphique pour l’analyse des techniques d’interaction en termes (1) d’assemblages de moteurs, qui accomplissent une tâche d’interaction atomique (assemblages de moteurs d’entrée), ou qui positionnent le corps pour percevoir les sorties du système (assemblages de moteurs de sortie); (2) de coordination des mouvements de ces assemblages de moteurs, relativement au corps de l’utilisateur ou à son environnement interactif.Nous avons appliqué BodyScape à : 1) la caractérisation du rôle du support dans l’étude de nouvelles interactions bimanuelles pour dispositifs mobiles; 2) l’analyse des effets de mouvements concurrents lorsque l’interaction et son support impliquent le même membre; et 3) la comparaison de douze techniques d’interaction multi-échelle afin d’évaluer le rôle du guidage et des interférences sur la performance.La caractérisation des interaction avec BodyScape clarifie le rôle du support des dispositifs d’interaction sur l’équilibre de l’utilisateur, et donc sur le confort d’utilisation et la performance qui en découlent. L’espace de conception permet aussi aux concepteurs d’interactions d’identifier des situations dans lesquelles des mouvements peuvent interférer entre eux et donc diminuer performance et confort. Enfin, BodyScape révèle les compromis à considérer a priori lors de la combinaison de plusieurs techniques d’interaction, permettant l’analyse et la génération de techniques d’interaction variées pour les environnements multi-surfaces.Plus généralement, cette thèse défend l’idée qu’en adoptant une approche centrée sur les fonctions corporelles engagées au cours de l’interaction, il est possible de maîtriser la complexité de la conception de techniques d’interaction dans les environnements multi-surfaces, mais aussi dans un cadre plus général. / This thesis introduces BodyScape, a body-centric framework that accounts for how users coordinate their movements within and across their own limbs in order to interact with a wide range of devices, across multiple surfaces. It introduces a graphical notation that describes interaction techniques in terms of (1) motor assemblies responsible for performing a control task (input motor assembly) or bringing the body into a position to visually perceive output (output motor assembly), and (2) the movement coordination of motor assemblies, relative to the body or fixed in the world, with respect to the interactive environment. This thesis applies BodyScape to 1) investigate the role of support in a set of novel bimanual interaction techniques for hand-held devices, 2) analyze the competing effect across multiple input movements, and 3) compare twelve pan-and-zoom techniques on a wall-sized display to determine the roles of guidance and interference on performance. Using BodyScape to characterize interaction clarifies the role of device support on the user's balance and subsequent comfort and performance. It allows designers to identify situations in which multiple body movements interfere with each other, with a corresponding decrease in performance. Finally, it highlights the trade-offs among different combinations of techniques, enabling the analysis and generation of a variety of multi-surface interaction techniques. I argue that including a body-centric perspective when defining interaction techniques is essential for addressing the combinatorial explosion of interactive devices in multi-surface environments.

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