Tato diplomová práce se zabývá výzkumem na téma vlivu prostorové koherence osvětlení. Účelem je určit schopnost osové lokalizace při zobrazení Koherencí řízeným holografickým mikroskopem (CCHM) v závislosti na různé prostorové koherenci světelného zdroje. Osová lokalizace je v tomto případě zkoumána jako kvalita rozlišení drobných detailů trojrozměrného vzorku, umístěných nad sebou. Teorie zobrazení holografickým mikroskopem a teorie rozptylu v nehomogenních prostředích je shrnuta v první části práce, v rozsahu nutném pro pochopení části praktické. Základní princip fungování mikroskopu a přesný popis jeho uspořádání je zde podrobně popsán. Proběhl mechanický návrh stavební úpravy mikroskopu tak, aby bylo možno využívat kondenzorovou optiku s vysokou numerickou aperturou a omezenými optickými vadami. Několik různých přístupů, které by mohly vést ke zlepšení zobrazovacích vlastností mikroskopu, bylo navrženo a vyzkoušeno a jsou zde popsány i s jejich výhodami a nevýhodami. Pro experimentální část práce byl vyroben modelový vzorek. Závislost osové lokalizace na prostorové koherenci osvětlení byla demonstrována pomocí simulace a následně ověřena experimentálně, pozorováním vyrobeného modelového vzorku. Experimentální výsledky potvrzují základní principy vycházející ze zmíněné teorie. Na závěr jsou navržena možná vylepšení, pro budoucí zpřesnění výsledků.

Dans la modélisation et l'évaluation des performances de la communication cellulaire sans fil, la géométrie stochastique est largement appliquée afin de fournir des solutions plus efficaces et plus précises. Le processus ponctuel de Poisson homogène (H-PPP), est le processus ponctuel le plus largement utilisé pour modéliser les emplacements spatiaux des stations de base (BS) en raison de sa facilité de traitement mathématique et de sa simplicité. Pour les fortes corrélations spatiales entre les emplacements des stations de base, seuls les processus ponctuels (PP) avec inhibitions et attractions spatiales peuvent être utiles. Cependant, le temps de simulation long et la faible aptitude mathématique rendent les PP non-Poisson non adaptés à l'évaluation des performances au niveau du système. Par conséquent, pour surmonter les problèmes mentionnés, nous avons les contributions suivantes dans cette thèse: Premièrement, nous introduisons une nouvelle méthodologie de modélisation et d’analyse de réseaux cellulaires de liaison descendante, dans laquelle les stations de base constituent un processus ponctuel invariant par le mouvement qui présente un certain degré d’interaction entre les points. L'approche proposée est basée sur la théorie des PP inhomogènes de Poisson (I-PPP) et est appelée approche à double amincissement non homogène (IDT). L’approche proposée consiste à approximer le PP initial invariant par le mouvement avec un PP équivalent constitué de la superposition de deux I-PPP conditionnellement indépendants. Les inhomogénéités des deux PP sont créées du point de vue de l'utilisateur type ``centré sur l'utilisateur''. Des conditions suffisantes sur les paramètres des fonctions d'amincissement qui garantissent une couverture meilleure ou pire par rapport au modèle de PPP homogène de base sont identifiées. La précision de l'approche IDT est justifiée à l'aide de données empiriques sur la distribution spatiale des stations de base. Ensuite, sur la base de l’approche IDT, une nouvelle expression analytique traitable du rapport de brouillage moyen sur signal (MISR) des réseaux cellulaires où les stations de base présentent des corrélations spatiales est introduite. Pour les PP non-Poisson, nous appliquons l'approche IDT proposée pour estimer les performances des PP non-Poisson. En prenant comme exemple le processus de points β-Ginibre ( β -GPP), nous proposons de nouvelles fonctions d’approximation pour les paramètres clés dans l’approche IDT afin de modéliser différents degrés d’inhibition spatiale et de prouver que MISR est constant en densification de réseau. Nous prouvons que la performance MISR dans le cas β-GPP ne dépend que du degré de répulsion spatiale, c'est-à-dire β , quelles que soient les densités de BS. Les nouvelles fonctions d'approximation et les tendances sont validées par des simulations numériques.Troisièmement nous étudions plus avant la méta-distribution du SIR à l’aide de l’approche IDT. La méta-distribution est la distribution de la probabilité de réussite conditionnelle compte tenu du processus de points. Nous dérivons et comparons l'expression sous forme fermée pour le b-ème moment dans les cas PP H-PPP et non-Poisson. Le calcul direct de la fonction de distribution cumulative complémentaire (CCDF) pour la méta-distribution n'étant pas disponible, nous proposons une méthode numérique simple et précise basée sur l'inversion numérique des transformées de Laplace. L'approche proposée est plus efficace et stable que l'approche conventionnelle utilisant le théorème de Gil-Pelaez. La valeur asymptotique de la CCDF de la méta distribution est calculée dans la nouvelle définition de la probabilité de réussite. En outre, la méthode proposée est comparée à certaines autres approximations et limites, par exemple l’approximation bêta, les bornes de Markov et les liaisons de Paley-Zygmund. Cependant, les autres modèles et limites d'approximation sont comparés pour être moins précis que notre méthode proposée. / In the modeling and performance evaluation of wireless cellular communication, stochastic geometry is widely applied, in order to provide more efficient and accurate solutions. Homogeneous Poisson point process (H-PPP) with identically independently distributed variables, is the most widely used point process to model the spatial locations of base stations (BSs) due to its mathematical tractability and simplicity. For strong spatial correlations between locations of BSs, only point processes (PPs) with spatial inhibitions and attractions can help. However, the long simulation time and weak mathematical tractability make non-Poisson PPs not suitable for system level performance evaluation. Therefore, to overcome mentioned problems, we have the following contributions in this thesis: First, we introduce a new methodology for modeling and analyzing downlink cellular networks, where the base stations constitute a motion-invariant point process that exhibits some degree of interactions among the points. The proposed approach is based on the theory of inhomogeneous Poisson PPs (I-PPPs) and is referred to as inhomogeneous double thinning (IDT) approach. The proposed approach consists of approximating the original motion-invariant PP with an equivalent PP that is made of the superposition of two conditionally independent I-PPPs. The inhomogeneities of both PPs are created from the point of view of the typical user. The inhomogeneities are mathematically modeled through two distance-dependent thinning functions and a tractable expression of the coverage probability is obtained. Sufficient conditions on the parameters of the thinning functions that guarantee better or worse coverage compared with the baseline homogeneous PPP model are identified. The accuracy of the IDT approach is substantiated with the aid of empirical data for the spatial distribution of the BSs. Then, based on the IDT approach, a new tractable analytical expression of mean interference to signal ratio (MISR) of cellular networks where BSs exhibits spatial correlations is introduced.For non-Poisson PPs, we apply proposed IDT approach to approximate the performance of non-Poisson PPs. Taking β-Ginibre point process (β -GPP) as an example, we propose new approximation functions for key parameters in IDT approach to model different degree of spatial inhibition and we successfully prove that MISR for β -GPP is constant under network densification with our proposed approximation functions. We prove that of MISR performance under β-GPP case only depends on the degree of spatial repulsion, i.e., β , regardless of different BS densities. We also prove that with the increase of β or (given fixed γ or β respectively), the corresponding MISR for β-GPP decreases. The new approximation functions and the trends are validated by numerical simulations. Third, we further study meta distribution of the SIR with the help of the IDT approach. Meta distribution is the distribution of the conditional success probability given the point process. We derive and compare the closed-form expression for the b-th moment under H-PPP and non-Poisson PP case. Since the direct computation of the complementary cumulative distribution function (CCDF) for meta distribution is not available, we propose a simple and accurate numerical method based on numerical inversion of Laplace transforms. The proposed approach is more efficient and stable than the conventional approach using Gil-Pelaez theorem. The asymptotic value of CCDF of meta distribution is computed under new definition of success probability. Furthermore, the proposed method is compared with some other approximations and bounds, e.g., beta approximation, Markov bounds and Paley-Zygmund bound. However, the other approximation models and bounds are compared to be less accurate than our proposed method.

The spin transport and dynamics of optically injected spin polarized carri- ers are studied with a high spatial and/or time resolution in semiconductor GaAs-based heterostructures in multiple transport regimes. An unexpectedly long-scale and high-speed spin diffusion transport is observed in a long-lived electron sub-system induced optically at an undoped single GaAs/AlGaAs heterointerface. A diffusion and drift-dominated spin transport is investi- gated using an electrical spin-detection via the inverse spin Hall effect in doped GaAs-based systems at room and low temperatures. It is shown that the inverse spin Hall signal and the spin transport parameters can be con- trolled by a direct application of an electric field or by expanding a depleted zone of a planar pn-junction.

Title: Multicomponent plasma polymers with spatially controlled properties Author: MSc. Pavel Pleskunov Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Prof. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics / Charles University Abstract: Mixing of two (or more) polymers often leads to phase separation and to the formation of nanoscale architecture, which can be highly attractive in various applications including controllable drug delivery, fabrication of separation and solid electrolyte membranes, gas storage, etc. Different wet-chemistry techniques already exist to produce nanophase-separated polymers; however, capturing the resultant polymeric structure in a predictable manner remains a challenging task. In this thesis, a low-temperature plasma-based strategy is investigated for the production of multicomponent thin films of plasma polymers with spatially discriminated nanoscale domains. Gas aggregation cluster source is used for the fabrication of nanoparticles of plasma polymerized acrylic acid, whereas Plasma-Assisted Vapor Phase Deposition is used for the deposition of thin films of poly(ethylene oxide) plasma polymer. Embedding of nanoparticles into matrices of thermodynamically incompatible plasma polymer as well as...

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The success of smartphones and tablets clearly shows that the fusion of input and output within one device can lead to a more direct and natural interaction. While a bigger part of previous research was devoted to the development of techniques for such touch-sensitive displays, this dissertation goes beyond the limitations of an interactive surface and extends the interaction to the physical space above a digital table by means of handheld spatially aware displays. By incorporating their spatial position and orientation, those displays add a further major input channel to the interaction. Even though this idea is not entirely new, the potential of using spatially aware displays (Tangible Displays) above a digital tabletop has rarely been used and requires systematic examination. In pursuit of lessening this gap, this dissertation makes three major contributions: (1) The conceptual framework has been developed as a guide for the design of Tangible Display applications. It offers a systematic description and analysis of the design space under investigation and its basic interaction principles. This includes a detailed overview of the general system components and underlying types of input as well as a categorization of common interaction and usage patterns. Based on that, a classification of four common types of information spaces is provided along with a set of novel techniques for their spatial exploration in midair above a tabletop. On an empirical level, the framework is supported by two comprehensive studies that investigate key aspects of spatial interaction. (2) To facilitate the rapid prototyping of interactive Tangible Display applications, a unifying technological framework has been designed and implemented that integrates the necessary sensor and display hardware and provides simple access to it through an easy-to-use API. Along with a modular architectural design, the API does not only encapsulate the complexity of the underlying input and output technologies, but also allows for their seamless substitution by alternative approaches. (3) On a practical level, the conceptual and technological framework have been validated by four comprehensive interactive systems. Those systems served as a testbed for the iterative development and formative assessment of various novel interaction techniques tailored to address basic tasks in common fields of application. The gathered insights helped refine the conceptual and technological framework and are a valuable starting point for the development of future systems.:Abstract iii Zusammenfassung v Acknowledgements vii Publications ix Supervised Student Theses xiii Acronyms xv Contents xix 1 Introduction 1 1.1 Goals of this Thesis 1.1.1 Research Challenges 1.1.2 Research Objectives 1.2 Scope of this Thesis 1.3 Methodological Approach 1.4 Contributions and Thesis Outline PART I: Conceptual Framework 2 Research Background 2.1 General Research Context 2.1.1 Post-WIMP & Reality-Based Interaction 2.1.2 Ubiquitous Computing 2.1.3 Augmented Reality and Environments 2.2 Interactive Surfaces 2.2.1 Advanced Form Factors 2.2.2 Interaction Beyond the Surface 2.2.3 Multi-display Environments 2.3 Tangible User Interfaces 2.3.1 Basic TUI Genres 2.3.2 Contributions and Qualities of TUI 2.4 Spatially Aware Displays 2.4.1 Potential Benefits 2.4.2 Spatially Aware Displays in Multi-Display Environments 2.4.3 A TUI Genre of its Own:Tangible Displays 2.5 Summary 3 Studying Spatial Input-based Zoom & Pan on Handheld Displays 3.1 Goals and Scope of the Study 3.1.1 Factors of Influence 3.1.2 Hypotheses 3.1.3 Scope of the Study 3.2 Design Rationale 3.2.1 Mapping the Physical to the Virtual World 3.2.2 Clutching and Relative Mode 3.2.3 Zooming and Panning 3.2.4 Responsiveness of the Prototype 3.3 Method 3.3.1 Study Design 3.3.2 Participants 3.3.3 Apparatus 3.3.4 Scenario and Task Design 3.3.5 Procedure 3.4 Results 3.4.1 Statistical Methodology & Collected Performance Data 3.4.2 Analysis of Completion Times 3.4.3 Analysis of Discrete Actions 3.4.4 Utilized Motor Space (Spatial Condition Only) 3.4.5 User Feedback & Fatigue 3.5 Discussion 3.5.1 Verification of Hypotheses 3.5.2 Further Observations 3.5.3 Explaining the Effects 3.5.4 Limitations 3.6 Future Generations of Mobile Displays 3.6.1 Device-Intrinsic Spatial Tracking 3.6.2 A Built-in Tactile Clutch 3.7 Summary 4 Design Space & Interaction Framework 4.1 Design Dimensions 4.1.1 Principle Setup & System Components 4.1.2 Basic Types of Input 4.1.3 Spatial Zones 4.2 Interaction Vocabulary 4.2.1 Vocabulary Based on Spatial Input 4.2.2 Vocabulary Based on Head Input 4.2.3 Vocabulary Based on Surface Input 4.2.4 Vocabulary Inspired by the Representation Aspect 4.3 Topologies for Representing Virtual Spaces 4.3.1 3D Volumes 4.3.2 Zoom Pyramids 4.3.3 Multi-layer Stacks 4.4 Classes of Explorable Information Spaces 4.4.1 Volumetric Information Spaces 4.4.2 Zoomable Information Spaces 4.4.3 Layered Information Spaces 4.4.4 Temporal Information Spaces 4.5 Summary 5 Studying Multi-layer Interaction Above a Tabletop 5.1 Goals and Scope of the Study 5.1.1 Basic Interaction Tasks 5.1.2 Previous Evaluations 5.1.3 Scope of the Study 5.2 Method 5.2.1 Participants 5.2.2 Study Design & Tasks 5.2.3 Procedure 5.2.4 Apparatus 5.3 Results 5.3.1 Collected Performance Data & Statistical Methodology 5.3.2 Basic Analysis Concerning the Three Interaction Tasks 5.3.3 Further Analysis Regarding Interaction Zones 5.3.4 Questionnaires & User Preferences 5.4 Discussion 5.4.1 Layer Thicknesses & Accuracy 5.4.2 Physical Interaction Space & Number of Layers 5.4.3 Design Recommendations & Further Observations 5.5 Summary PART II: Technological Framework 6 Technological Background 101 6.1 Basic Display Approaches 6.1.1 Projective Displays 6.1.2 Active Displays 6.2 Tracking Technologies for Handheld Displays 6.2.1 Infrared Marker Systems 6.2.2 Depth Sensor Systems 6.3 Technologies for Sensing Surface Input 6.3.1 Sensing Touch Input 6.3.2 Digital Pens and Paper 6.4 Summary 7 A Tangible Display Toolkit for Research Labs 7.1 Toolkit Architecture 7.1.1 History and General Overview 7.1.2 Lab and Mobile Setup 7.2 Toolkit Subsystems 7.2.1 Projection Subsystem 7.2.2 Spatial Input Subsystem 7.2.3 Surface Input Subsystem 7.3 Toolkit Interfaces 7.3.1 Inter-process Communication 7.3.2 Servers & UI Tools 7.3.3 Application Programming Interface 7.4 Summary 8 Towards a Tangible Display Ecosystem for Everyone 8.1 Motivation and Vision 8.1.1 Envisioned Hardware Setup 8.1.2 Proactive Cooperation Among Devices 8.2 Revision of the Previous Lab Setup 8.3 Case Study: Tracking via a Low-cost Depth Sensor 8.3.1 Implemented Tracking Algorithm 8.3.2 Evaluation 8.3.3 Areas of Improvement 8.4 Summary PART III: Tangible Display Systems 9 Tangible Lenses for Multimedia Information Spaces 9.1 Case Studies 9.1.1 Volume Slicer 9.1.2 Picture Zoomer 9.1.3 Layer Explorer 9.1.4 Video Browser 9.2 Evaluation 9.2.1 Study Design 9.2.2 Findings 9.3 Improved Navigation Techniques 9.3.1 Navigating through Information Layers 9.3.2 Navigational Aids 9.4 Annotating the Space Above the Tabletop 9.4.1 Creation of Annotations 9.4.2 Guided Exploration of Annotations 9.5 Summary 10 Tangible Views for Information Visualization 10.1 Background and Motivation 10.1.1 Conventional Interactive Visualization 10.1.2 Towards More Direct Interaction in InfoVis 10.1.3 Narrowing the Gap 10.2 The Tangible Views Concept 10.3 Case Studies 10.3.1 Graph Visualization 10.3.2 Scatter Plot 10.3.3 Parallel Coordinates Plot 10.3.4 Matrix Visualization 10.3.5 Space-Time-Cube Visualization 10.4 Initial User Experience & Discussion 10.4.1 Observations 10.4.2 Limitations 10.5 Potential Future Directions 10.5.1 Technology Gap 10.5.2 Integration Gap 10.5.3 Guidelines Gap 10.6 Summary 11 Tangible Palettes for Graphical Applications 11.1 Background and Motivation 11.2 The Tangible Palettes Concept 11.2.1 Spatial Work Zones 11.2.2 Previous Techniques Revisited 11.2.3 Allocating GUI Palettes to Tangible Displays 11.3 Interactive Prototype 11.3.1 Basic Functionality: Drawing and Document Navigation 11.3.2 Inter-Display Transfer of Palettes 11.3.3 Temporary Fade-out of Tool Palettes 11.3.4 Quick Access to Tool Palettes via Spatial Work Zones 11.3.5 Handling of Stacked Graphics Layers 11.4 Initial User Experience & Discussion 11.4.1 General Impression and Limitations 11.4.2 Document Navigation with Handheld Displays 11.4.3 Tool Organization with Spatial Work Zones 11.5 Summary 12 Tangible Windows for 3D Virtual Reality 193 12.1 Background and Motivation 12.1.1 Basic 3D Display Approaches 12.1.2 Seminal 3D User Interfaces 12.2 TheTangibleWindowsConcept 12.2.1 Windows into Virtuality 12.2.2 Head-coupled Perspectives 12.2.3 Tangible Windows Above a Digital Workbench 12.3 Interaction Techniques 12.3.1 Global Viewpoint Control on the Tabletop 12.3.2 Scene Exploration 12.3.3 Object Selection 12.3.4 Object Manipulation 12.3.5 Object Inspection 12.3.6 Global Scene Navigation on the Tabletop 12.4 Application Scenarios & Case Studies 12.4.1 Virtual Sandbox 12.4.2 Interior Designer 12.4.3 Medical Visualization 12.5 Initial User Experience & Discussion 12.5.1 Limitations 12.5.2 Precision and Constraints 12.5.3 More Permanent Representations 12.5.4 Head-coupled Perspectives and Head Input 12.6 Summary 13 Conclusion 13.1 Summary of Contributions 13.1.1 Major Contributions 13.1.2 Minor Contributions 13.2 Critical Reflection 13.2.1 General Limitations due to the Dissertation Scope 13.2.2 Limitations of the Techniques 13.2.3 Limitations of the Studies 13.3 Directions for Future Work 13.3.1 Adaptation to other Settings and Domains 13.3.2 Further Development of the Techniques 13.3.3 Current Developments 13.4 Closing Remarks A Appendix A.1 Materials for Chapter3 (Zoom & Pan Study) A.1.1 List of the 128 Zoom and Pan Tasks A.1.2 Usability Questionnaires A.2 Questionnaires for Chapter 5 (Multi-layer Stack Study) A.3 Materials for Section 9.2 (Evaluation of Tangible Lenses) A.3.1 Scratchpad for Study Leader A.3.2 Usability Questionnaires Bibliography List of Figures List of Tables / Der Erfolg von Smartphones und Tablets hat deutlich gezeigt, dass die Verschmelzung von Ein- und Ausgabe im selben Gerät zu einer direkteren und als natürlicher empfundenen Interaktion führen kann. Während sich ein Großteil bisheriger Forschung der Entwicklung von Touchtechniken auf derartigen berührungsempfindlichen Displays widmet, löst sich diese Dissertation von den Beschränkungen der Interaktion auf Oberflächen und erweitert diese auf den physischen Raum oberhalb eines digitalen Tisches mittels handgehaltener, lagebewusster Displays. Durch die Einbeziehung der räumlichen Position und Orientierung solcher „Tangible Displays” steht ein vielversprechender, zusätzlicher Eingabekanal zur Verfügung. Wenngleich diese Idee nicht vollständig neu ist, wurden die vielfältigen Möglichkeiten, die sich durch ihren Einsatz über einem digitalen Tisch ergeben, bisher wenig genutzt. Im Bestreben diese Lücke zu verringern, leistet diese Dissertation drei wesentliche Beträge: (1) Das Konzeptuelle Rahmenwerk wurde als Leitfaden für den Entwurf von Tangible Display- Anwendungen entwickelt. Es bietet eine systematische Beschreibung und Analyse des zu untersuchenden Entwurfsraums und seiner grundlegenden Interaktionsprinzipien. Neben einer detaillierten Übersicht aller Systemkomponenten und Eingabearten beinhaltet dies vor allem eine Kategorisierung von typischen Interaktions- und Nutzungsmustern. Darauf basierend wird ein neuartiger vereinheitlichender Ansatz zur räumlichen Interaktion mit verschiedenen gängigen Klassen von Informationsräumen über einem Tabletop vorgestellt. Auf empirischer Ebene wird das Konzeptuelle Rahmenwerk durch zwei umfangreiche Studien gestützt, in denen Kernaspekte der räumlichen Interaktion mit handgehaltenen Displays untersucht wurden. (2) Um die Entwicklung von interaktiven Anwendungen zu ermöglichen, wurde ein Technisches Rahmenwerk entworfen und umgesetzt, das die Sensor- und Displayhardware zusammenfasst und einfachen Zugriff darauf mittels eines API bietet. Im Zusammenspiel mit der modularen Software-Architektur kapselt das API nicht nur die Komplexität der verwendeten Ein- und Ausgabetechnologien, sondern ermöglicht auch deren nahtlosen Austausch durch alternative Lösungsansätze. (3) Die Tauglichkeit des Konzeptuellen und des Technischen Rahmenwerkes wird durch vier umfangreiche interaktive Systeme demonstriert. Diese Systeme dienten als Testumgebung für die iterative Entwicklung und formative Bewertung einer Reihe von neuartigen Interaktionstechniken, die gängige Basisaufgaben in verschiedenen Anwendungsbereichen adressieren. Die dabei gewonnenen Erkenntnisse halfen, das Konzeptuelle und das Technische Rahmenwerk zu verfeinern, welche einen wertvollen Ausgangspunkt für die Entwicklung von zukünftigen interaktiven Tangible Display-Systemen bilden.:Abstract iii Zusammenfassung v Acknowledgements vii Publications ix Supervised Student Theses xiii Acronyms xv Contents xix 1 Introduction 1 1.1 Goals of this Thesis 1.1.1 Research Challenges 1.1.2 Research Objectives 1.2 Scope of this Thesis 1.3 Methodological Approach 1.4 Contributions and Thesis Outline PART I: Conceptual Framework 2 Research Background 2.1 General Research Context 2.1.1 Post-WIMP & Reality-Based Interaction 2.1.2 Ubiquitous Computing 2.1.3 Augmented Reality and Environments 2.2 Interactive Surfaces 2.2.1 Advanced Form Factors 2.2.2 Interaction Beyond the Surface 2.2.3 Multi-display Environments 2.3 Tangible User Interfaces 2.3.1 Basic TUI Genres 2.3.2 Contributions and Qualities of TUI 2.4 Spatially Aware Displays 2.4.1 Potential Benefits 2.4.2 Spatially Aware Displays in Multi-Display Environments 2.4.3 A TUI Genre of its Own:Tangible Displays 2.5 Summary 3 Studying Spatial Input-based Zoom & Pan on Handheld Displays 3.1 Goals and Scope of the Study 3.1.1 Factors of Influence 3.1.2 Hypotheses 3.1.3 Scope of the Study 3.2 Design Rationale 3.2.1 Mapping the Physical to the Virtual World 3.2.2 Clutching and Relative Mode 3.2.3 Zooming and Panning 3.2.4 Responsiveness of the Prototype 3.3 Method 3.3.1 Study Design 3.3.2 Participants 3.3.3 Apparatus 3.3.4 Scenario and Task Design 3.3.5 Procedure 3.4 Results 3.4.1 Statistical Methodology & Collected Performance Data 3.4.2 Analysis of Completion Times 3.4.3 Analysis of Discrete Actions 3.4.4 Utilized Motor Space (Spatial Condition Only) 3.4.5 User Feedback & Fatigue 3.5 Discussion 3.5.1 Verification of Hypotheses 3.5.2 Further Observations 3.5.3 Explaining the Effects 3.5.4 Limitations 3.6 Future Generations of Mobile Displays 3.6.1 Device-Intrinsic Spatial Tracking 3.6.2 A Built-in Tactile Clutch 3.7 Summary 4 Design Space & Interaction Framework 4.1 Design Dimensions 4.1.1 Principle Setup & System Components 4.1.2 Basic Types of Input 4.1.3 Spatial Zones 4.2 Interaction Vocabulary 4.2.1 Vocabulary Based on Spatial Input 4.2.2 Vocabulary Based on Head Input 4.2.3 Vocabulary Based on Surface Input 4.2.4 Vocabulary Inspired by the Representation Aspect 4.3 Topologies for Representing Virtual Spaces 4.3.1 3D Volumes 4.3.2 Zoom Pyramids 4.3.3 Multi-layer Stacks 4.4 Classes of Explorable Information Spaces 4.4.1 Volumetric Information Spaces 4.4.2 Zoomable Information Spaces 4.4.3 Layered Information Spaces 4.4.4 Temporal Information Spaces 4.5 Summary 5 Studying Multi-layer Interaction Above a Tabletop 5.1 Goals and Scope of the Study 5.1.1 Basic Interaction Tasks 5.1.2 Previous Evaluations 5.1.3 Scope of the Study 5.2 Method 5.2.1 Participants 5.2.2 Study Design & Tasks 5.2.3 Procedure 5.2.4 Apparatus 5.3 Results 5.3.1 Collected Performance Data & Statistical Methodology 5.3.2 Basic Analysis Concerning the Three Interaction Tasks 5.3.3 Further Analysis Regarding Interaction Zones 5.3.4 Questionnaires & User Preferences 5.4 Discussion 5.4.1 Layer Thicknesses & Accuracy 5.4.2 Physical Interaction Space & Number of Layers 5.4.3 Design Recommendations & Further Observations 5.5 Summary PART II: Technological Framework 6 Technological Background 101 6.1 Basic Display Approaches 6.1.1 Projective Displays 6.1.2 Active Displays 6.2 Tracking Technologies for Handheld Displays 6.2.1 Infrared Marker Systems 6.2.2 Depth Sensor Systems 6.3 Technologies for Sensing Surface Input 6.3.1 Sensing Touch Input 6.3.2 Digital Pens and Paper 6.4 Summary 7 A Tangible Display Toolkit for Research Labs 7.1 Toolkit Architecture 7.1.1 History and General Overview 7.1.2 Lab and Mobile Setup 7.2 Toolkit Subsystems 7.2.1 Projection Subsystem 7.2.2 Spatial Input Subsystem 7.2.3 Surface Input Subsystem 7.3 Toolkit Interfaces 7.3.1 Inter-process Communication 7.3.2 Servers & UI Tools 7.3.3 Application Programming Interface 7.4 Summary 8 Towards a Tangible Display Ecosystem for Everyone 8.1 Motivation and Vision 8.1.1 Envisioned Hardware Setup 8.1.2 Proactive Cooperation Among Devices 8.2 Revision of the Previous Lab Setup 8.3 Case Study: Tracking via a Low-cost Depth Sensor 8.3.1 Implemented Tracking Algorithm 8.3.2 Evaluation 8.3.3 Areas of Improvement 8.4 Summary PART III: Tangible Display Systems 9 Tangible Lenses for Multimedia Information Spaces 9.1 Case Studies 9.1.1 Volume Slicer 9.1.2 Picture Zoomer 9.1.3 Layer Explorer 9.1.4 Video Browser 9.2 Evaluation 9.2.1 Study Design 9.2.2 Findings 9.3 Improved Navigation Techniques 9.3.1 Navigating through Information Layers 9.3.2 Navigational Aids 9.4 Annotating the Space Above the Tabletop 9.4.1 Creation of Annotations 9.4.2 Guided Exploration of Annotations 9.5 Summary 10 Tangible Views for Information Visualization 10.1 Background and Motivation 10.1.1 Conventional Interactive Visualization 10.1.2 Towards More Direct Interaction in InfoVis 10.1.3 Narrowing the Gap 10.2 The Tangible Views Concept 10.3 Case Studies 10.3.1 Graph Visualization 10.3.2 Scatter Plot 10.3.3 Parallel Coordinates Plot 10.3.4 Matrix Visualization 10.3.5 Space-Time-Cube Visualization 10.4 Initial User Experience & Discussion 10.4.1 Observations 10.4.2 Limitations 10.5 Potential Future Directions 10.5.1 Technology Gap 10.5.2 Integration Gap 10.5.3 Guidelines Gap 10.6 Summary 11 Tangible Palettes for Graphical Applications 11.1 Background and Motivation 11.2 The Tangible Palettes Concept 11.2.1 Spatial Work Zones 11.2.2 Previous Techniques Revisited 11.2.3 Allocating GUI Palettes to Tangible Displays 11.3 Interactive Prototype 11.3.1 Basic Functionality: Drawing and Document Navigation 11.3.2 Inter-Display Transfer of Palettes 11.3.3 Temporary Fade-out of Tool Palettes 11.3.4 Quick Access to Tool Palettes via Spatial Work Zones 11.3.5 Handling of Stacked Graphics Layers 11.4 Initial User Experience & Discussion 11.4.1 General Impression and Limitations 11.4.2 Document Navigation with Handheld Displays 11.4.3 Tool Organization with Spatial Work Zones 11.5 Summary 12 Tangible Windows for 3D Virtual Reality 193 12.1 Background and Motivation 12.1.1 Basic 3D Display Approaches 12.1.2 Seminal 3D User Interfaces 12.2 TheTangibleWindowsConcept 12.2.1 Windows into Virtuality 12.2.2 Head-coupled Perspectives 12.2.3 Tangible Windows Above a Digital Workbench 12.3 Interaction Techniques 12.3.1 Global Viewpoint Control on the Tabletop 12.3.2 Scene Exploration 12.3.3 Object Selection 12.3.4 Object Manipulation 12.3.5 Object Inspection 12.3.6 Global Scene Navigation on the Tabletop 12.4 Application Scenarios & Case Studies 12.4.1 Virtual Sandbox 12.4.2 Interior Designer 12.4.3 Medical Visualization 12.5 Initial User Experience & Discussion 12.5.1 Limitations 12.5.2 Precision and Constraints 12.5.3 More Permanent Representations 12.5.4 Head-coupled Perspectives and Head Input 12.6 Summary 13 Conclusion 13.1 Summary of Contributions 13.1.1 Major Contributions 13.1.2 Minor Contributions 13.2 Critical Reflection 13.2.1 General Limitations due to the Dissertation Scope 13.2.2 Limitations of the Techniques 13.2.3 Limitations of the Studies 13.3 Directions for Future Work 13.3.1 Adaptation to other Settings and Domains 13.3.2 Further Development of the Techniques 13.3.3 Current Developments 13.4 Closing Remarks A Appendix A.1 Materials for Chapter3 (Zoom & Pan Study) A.1.1 List of the 128 Zoom and Pan Tasks A.1.2 Usability Questionnaires A.2 Questionnaires for Chapter 5 (Multi-layer Stack Study) A.3 Materials for Section 9.2 (Evaluation of Tangible Lenses) A.3.1 Scratchpad for Study Leader A.3.2 Usability Questionnaires Bibliography List of Figures List of Tables

<p>Imaging and computer vision systems deployed in real-world environments face the challenge of accommodating a wide range of lighting conditions. However, the cost, the demand for high resolution, and the miniaturization of imaging devices impose physical constraints on sensor design, limiting both the dynamic range and effective aperture size of each pixel. Consequently, conventional CMOS sensors fail to deliver satisfactory capture in high dynamic range scenes or under photon-limited conditions, thereby impacting the performance of downstream vision tasks. In this thesis, we address two key problems: 1) exploring the utilization of spatial multiplexing, specifically spatially varying exposure tiling, to extend sensor dynamic range and optimize scene capture, and 2) developing techniques to enhance the robustness of object detection systems under photon-limited conditions.</p> <p><br></p> <p>In addition to challenges imposed by natural environments, real-world vision systems are susceptible to adversarial attacks in the form of artificially added digital content. Therefore, this thesis presents a comprehensive pipeline for constructing a robust and scalable system to counter such attacks.</p>

We address the question of performance of large-scale networks with distributed feedback control. We consider networked dynamical systems with single and double integrator dynamics, subject to distributed disturbances. We focus on two types of problems. First, we consider problems modeled over regular lattice structures. Here, we treat consensus and vehicular formation problems and evaluate performance in terms of measures of “global order”, which capture the notion of network coherence. Second, we consider electric power networks, which we treat as dynamical systems modeled over general graphs. Here, we evaluate performance in terms of the resistive power losses that are incurred in maintaining network synchrony. These losses are associated with transient power flows that are a consequence of “local disorder” caused by lack of synchrony. In both cases, we characterize fundamental limitations to performance as networks become large. Previous studies have shown that such limitations hold for coherence in networks with regular lattice structures. These imply that connections in 3 spatial dimensions are necessary to achieve full coherence, when the controller uses static feedback from relative measurements in a local neighborhood. We show that these limitations remain valid also with dynamic feedback, where each controller has an internal memory state. However, if the controller can access certain absolute state information, dynamic feedback can improve performance compared to static feedback, allowing also 1-dimensional formations to be fully coherent. For electric power networks, we show that the transient power losses grow unboundedly with network size. However, in contrast to previous results, performance does not improve with increased network connectivity. We also show that a certain type of distributed dynamic feedback controller can improve performance by reducing losses, but that their scaling with network size remains an important limitation. / <p>QC 20160504</p>

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Cette thèse porte sur le rôle de l’espace dans l’organisation et dans la dynamique des communautés écologiques multi-espèces. Deux carences peuvent être identifiées dans les études théoriques actuelles portant sur la dimension spatiale des communautés écologiques : l’insuffisance de modèles multi-espèces représentant la dimension spatiale explicitement, et le manque d’attention portée aux interactions positives, tel le mutualisme, en dépit de la reconnaissance de leur ubiquité dans les systèmes écologiques. Cette thèse explore cette problématique propre à l’écologie des communautés, en utilisant une approche théorique s’inspirant de la théorie des systèmes complexes et de la mécanique statistique. Selon cette approche, les communautés d’espèces sont considérées comme des systèmes complexes dont les propriétés globales émergent des interactions locales entre les organismes qui les composent, et des interactions locales entre ces organismes et leur environnement. Le premier objectif de cette thèse est de développer un modèle de métacommunauté multi-espèces, explicitement spatial, orienté à l’échelle des individus et basé sur un réseau d’interactions interspécifiques générales comprenant à la fois des interactions d’exploitation, de compétition et de mutualisme. Dans ce modèle, les communautés locales sont formées par un processus d’assemblage des espèces à partir d’un réservoir régional. La croissance des populations est restreinte par une capacité limite et leur dynamique évolue suivant des mécanismes simples de reproduction et de dispersion des individus. Ces mécanismes sont dépendants des conditions biotiques et abiotiques des communautés locales et leur effet varie en fonction des espèces, du temps et de l’espace. Dans un deuxième temps, cette thèse a pour objectif de déterminer l’impact d’une connectivité spatiale croissante sur la dynamique spatiotemporelle et sur les propriétés structurelles et fonctionnelles de cette métacommunauté. Plus précisément, nous évaluons différentes propriétés des communautés en fonction du niveau de dispersion des espèces : i) la similarité dans la composition des communautés locales et ses patrons de corrélations spatiales; ii) la biodiversité locale et régionale, et la distribution locale de l’abondance des espèces; iii) la biomasse, la productivité et la stabilité dynamique aux échelles locale et régionale; et iv) la structure locale des interactions entre les espèces. Ces propriétés sont examinées selon deux schémas spatiaux. D’abord nous employons un environnement homogène et ensuite nous employons un environnement hétérogène où la capacité limite des communautés locales évoluent suivant un gradient. De façon générale, nos résultats révèlent que les communautés écologiques spatialement distribuées sont extrêmement sensibles aux modes et aux niveaux de dispersion des organismes. Leur dynamique spatiotemporelle et leurs propriétés structurelles et fonctionnelles peuvent subir des changements profonds sous forme de transitions significatives suivant une faible variation du niveau de dispersion. Ces changements apparaissent aussi par l’émergence de patrons spatiotemporels dans la distribution spatiale des populations qui sont typiques des transitions de phases observées généralement dans les systèmes physiques. La dynamique de la métacommunauté présente deux régimes. Dans le premier régime, correspondant aux niveaux faibles de dispersion des espèces, la dynamique d’assemblage favorise l’émergence de communautés stables, peu diverses et formées d’espèces abondantes et fortement mutualistes. La métacommunauté possède une forte diversité régionale puisque les communautés locales sont faiblement connectées et que leur composition demeure ainsi distincte. Par ailleurs dans le second régime, correspondant aux niveaux élevés de dispersion, la diversité régionale diminue au profit d’une augmentation de la diversité locale. Les communautés locales sont plus productives mais leur stabilité dynamique est réduite suite à la migration importante d’individus. Ce régime est aussi caractérisé par des assemblages incluant une plus grande diversité d’interactions interspécifiques. Ces résultats suggèrent qu’une augmentation du niveau de dispersion des organismes permet de coupler les communautés locales entre elles ce qui accroît la coexistence locale et favorise la formation de communautés écologiques plus riches et plus complexes. Finalement, notre étude suggère que le mutualisme est fondamentale à l’organisation et au maintient des communautés écologiques. Les espèces mutualistes dominent dans les habitats caractérisés par une capacité limite restreinte et servent d’ingénieurs écologiques en facilitant l’établissement de compétiteurs, prédateurs et opportunistes qui bénéficient de leur présence. / This thesis is a study of the role of space in the organization and dynamics of multi-species ecological communities. Two weaknesses can be identified from previous theoretical studies concerned with the spatial dimension of ecological communities: the scarcity of multi-species models based on a spatially explicit representation of space, and the lack of attention toward positive interspecific interactions, such as mutualism, despite the recognition of their ubiquity in ecological systems. This thesis explores this problematic by adopting a theoretical framework based on complex system theory and statistical mechanics. Following this approach, ecological communities can be viewed as complex systems whose global properties emerge from the local interactions between the organisms that composed them, and between the organisms and their environment. The first objective of this thesis is to develop a multi-species metacommunity model which is spatially explicit, individual-based, and centered on a general interspecific interaction web containing exploitation, competition as well as mutualism. In this model, local communities are created by an assembly process whereby species are drawn from a regional pool. Population growth is restricted by a carrying capacity and its dynamics is driven by simple reproduction and dispersal mechanisms acting at the level of single individual. These mechanisms depend on the biotic and abiotic conditions of the local communities and their effect varies with species, time and space. The second objective of this thesis is to determine the impact of an increasing spatial connectivity on the dynamics, and structural and functional properties of this metacommunity. More precisely, we set out to evaluate different community properties under changes in the level of species dispersal: i) the similarity in local community composition and its patterns of spatial correlations, ii) the local and regional diversity and the local species abundance, iii) the local and regional biomass, productivity and dynamical stability, and iv) the structure of the local interaction webs. These properties are examined under two spatial schemes. First, we employ a homogeneous environment, and second we employ a heterogeneous environment whereby the carrying capacity of local communities evolves along a gradient. In general, our results reveal that spatially distributed ecological communities are extremely sensitive to the modes and levels of species dispersal. Their spatiotemporal dynamics as well as their structural and functional properties can undergo profound changes in the form of significant transitions under slight changes of the level of dispersal. These changes are also highlighted by the emergence of spatiotemporal patterns in the spatial distribution of the populations, which are characteristics of phase transition generally observed in physical systems. The metacommunity presents two dynamical regimes. In the first regime, corresponding to weak levels of species dispersal, the assembly dynamics promotes the emergence of species-poor but stable communities made of abundant and strongly mutualistic species. The metacommunity has a high regional diversity since weakly connected communities conserve a distinct assemblage of species. On the other hand, in the second regime, corresponding to strong dispersal rates, regional diversity decreases at the benefit of an increase in local diversity. Local communities are more productive but their stability is reduced due to the important migration of individuals. This regime is also characterized by assemblages containing a richer diversity of interspecific interactions. These results suggest that an augmentation in the level of species dispersal permits organisms to couple local communities together which increases local coexistence and promotes the organization of richer and more complex ecological communities. Finally, our results suggest that mutualism is fundamental to the organization and persistence of ecological communities. Mutualistic species dominate in habitats characterized by a restricted carrying capacity and serve as ecological engineer by facilitating the establishment of competitors, predators and opportunists which benefit from their presence.