Nowadays a substantial trend occurs that vast amounts of geospatial data are supplied, managed, and processed over distributed GIS. It is important to provide users with the capability of visualising spatial data quality information in a meaningful way for distributed GIS, since it will significantly enhance user understanding of data quality and aid them in assessing the data fitness for their application requirements. This thesis investigates the issue of visualisation of spatial data quality for distributed GIS. Based on a review of core concepts associated with spatial data quality, metadata standards, and major research areas related to data quality, the limitations of current data quality presentation are highlighted. To overcome some of these limitations, the research topic of this thesis is proposed, namely, adding visualisation functionality to the presentation of spatial data quality to convey uncertainty information to users in an interactive and graphical manner. Based on a review of the theories on visualisation and the frameworks developed for visualisation of spatial data quality in literature, an extended framework is developed incorporating several aspects of visualisation such as contexts, contents, and techniques, where the hierarchical nature of data quality and error models are two main parts of the visualisation contents. A brief framework of visualisation of spatial data quality for distributed GIS is proposed, where data storage with quality information and web services for visualising data quality are two key components. To satisfy a series of requirements for representing spatial data quality, a new object-oriented data model is proposed based on the review of developments of data models. This data model can specifically deal with the hierarchical nature of data quality and error propagation, recognising data quality as a dynamic process. Further, The implementation of the data model using GML and SVG is discussed. The details of a web service for visualising spatial data quality are addressed. After proposing the requirements on building a system for spatial data quality visualisation for distributed GIS, the design of a prototype visualisation system for distributed GIS is addressed in detail. The prototype visualisation system for spatial data quality is developed and implemented with an example data set, where SVG and JavaScript are used to illustrate how various graphic methods such as animation, data quality filters, and colour gradients can be used for distributed GIS. In addition to the visualisation of positional accuracy at the feature level, in this pilot system, the hierarchical structure of data quality information is also presented. Limitations of the research in this thesis are also addressed. However, in general, this research is of great significance for the contributions made to a relatively new research area in terms of theories, procedures, and software developments.

Kwong-Wai, Chen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 114-118). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgments --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Volumetric Data --- p.1 / Chapter 1.2 --- Volume Visualization --- p.4 / Chapter 1.3 --- Thesis Contributions --- p.5 / Chapter 1.4 --- Thesis Outline --- p.6 / Chapter I --- Multi-body Surface Extraction --- p.8 / Chapter 2 --- Isosurface Extraction --- p.9 / Chapter 2.1 --- Previous Works --- p.10 / Chapter 2.1.1 --- Marching Cubes --- p.10 / Chapter 2.1.2 --- Skeleton Climbing --- p.12 / Chapter 2.1.3 --- Adaptive Skeleton Climbing --- p.14 / Chapter 2.2 --- Motivation --- p.17 / Chapter 3 --- Multi-body Surface Extraction --- p.19 / Chapter 3.1 --- Multi-body Surface --- p.19 / Chapter 3.2 --- Building 0-skeleton --- p.21 / Chapter 3.3 --- Building 1-skeleton --- p.23 / Chapter 3.3.1 --- Non-binary Faces --- p.24 / Chapter 3.3.2 --- Non-binary Cubes --- p.30 / Chapter 3.4 --- General Scheme for Messy Cubes --- p.33 / Chapter 3.4.1 --- Graph Reduction --- p.34 / Chapter 3.4.2 --- Position of the Tetrapoints --- p.36 / Chapter 3.5 --- Triangular Mesh Generation --- p.37 / Chapter 3.5.1 --- Generating the Edge Loops --- p.38 / Chapter 3.5.2 --- Triangulating the Edge Loops --- p.41 / Chapter 3.5.3 --- Incorporating with Adaptive Skeleton Climbing --- p.43 / Chapter 3.6 --- Implementation and Results --- p.45 / Chapter II --- Haptic Rendering of Volumetric Data --- p.60 / Chapter 4 --- Introduction to Haptics --- p.61 / Chapter 4.1 --- Terminology --- p.62 / Chapter 4.2 --- Haptic Rendering Process --- p.63 / Chapter 4.2.1 --- The Overall Process --- p.64 / Chapter 4.2.2 --- Force Profile --- p.65 / Chapter 4.2.3 --- Decoupling Processes --- p.66 / Chapter 4.3 --- The PHANToM´ёØ Haptic Interface --- p.67 / Chapter 4.4 --- Research Goals --- p.69 / Chapter 5 --- Haptic Rendering of Geometric Models --- p.70 / Chapter 5.1 --- Penalty Based Methods --- p.71 / Chapter 5.1.1 --- Vector Fields for Solid Objects --- p.71 / Chapter 5.1.2 --- Drawbacks of Penalty Based Methods --- p.72 / Chapter 5.2 --- Constraint Based Methods --- p.73 / Chapter 5.2.1 --- Virtual Haptic Interface Point --- p.73 / Chapter 5.2.2 --- The Constraints --- p.74 / Chapter 5.2.3 --- Location Computation --- p.78 / Chapter 5.2.4 --- Force Shading --- p.79 / Chapter 5.2.5 --- Adding Surface Properties --- p.80 / Chapter 6 --- Haptic Rendering of Volumetric Data --- p.83 / Chapter 6.1 --- Volume Haptization --- p.84 / Chapter 6.2 --- Isosurface Haptic Rendering --- p.86 / Chapter 6.3 --- Intermediate Representation Approach --- p.89 / Chapter 6.3.1 --- Introduction --- p.89 / Chapter 6.3.2 --- Intermediate Virtual Plane --- p.90 / Chapter 6.3.3 --- Updating Virtual Plane --- p.92 / Chapter 6.3.4 --- Preventing Force Discontinuity Artifacts --- p.93 / Chapter 6.3.5 --- Experiments and Results --- p.94 / Chapter 7 --- Conclusions and Future Research Directions --- p.98 / Chapter 7.1 --- Conclusions --- p.98 / Chapter 7.2 --- Future Research Directions --- p.99 / Chapter A --- Two Proofs of Multi-body Surface Extraction Algorithm --- p.101 / Chapter A.1 --- Graph Terminology and Theorems --- p.101 / Chapter A.2 --- Occurrence of Tripoints in Negative-Positive Pairs --- p.103 / Chapter A.3 --- Validity of the General Scheme --- p.103 / Chapter B --- An Example of Multi-body Surface Extraction Algorithm --- p.105 / Chapter B.1 --- Step 1: Building 0-Skeleton --- p.105 / Chapter B.2 --- Step 2: Building 1-Skeleton --- p.106 / Chapter B.2.1 --- Step 2a: Building 1-Skeleton and Tripoints on Cube Faces --- p.106 / Chapter B.2.2 --- Step 2b: Adding Tetrapoints and Tri-edges inside Cube --- p.106 / Chapter B.3 --- Step 3: Constructing Edge Loops and Triangulating --- p.109 / Bibliography --- p.114

Xie, Yongming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 77-85). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Isosurfaces --- p.1 / Chapter 1.2 --- Graphics Processing Unit --- p.2 / Chapter 1.3 --- Objective --- p.3 / Chapter 1.4 --- Contribution --- p.3 / Chapter 1.5 --- Thesis Organization --- p.4 / Chapter 2 --- Marching Cubes --- p.5 / Chapter 2.1 --- Introduction --- p.5 / Chapter 2.2 --- Marching Cubes Algorithm --- p.7 / Chapter 2.3 --- Triangulated Cube Configuration Table --- p.12 / Chapter 2.4 --- Summary --- p.16 / Chapter 3 --- Graphics Processing Unit --- p.18 / Chapter 3.1 --- Introduction --- p.18 / Chapter 3.2 --- History of Graphics Processing Unit --- p.19 / Chapter 3.2.1 --- First Generation GPU --- p.20 / Chapter 3.2.2 --- Second Generation GPU --- p.20 / Chapter 3.2.3 --- Third Generation GPU --- p.20 / Chapter 3.2.4 --- Fourth Generation GPU --- p.21 / Chapter 3.3 --- The Graphics Pipelining --- p.21 / Chapter 3.3.1 --- Standard Graphics Pipeline --- p.21 / Chapter 3.3.2 --- Programmable Graphics Pipeline --- p.23 / Chapter 3.3.3 --- Vertex Processors --- p.25 / Chapter 3.3.4 --- Fragment Processors --- p.26 / Chapter 3.3.5 --- Frame Buffer Operations --- p.28 / Chapter 3.4 --- GPU CPU Analogy --- p.31 / Chapter 3.4.1 --- Memory Architecture --- p.31 / Chapter 3.4.2 --- Processing Model --- p.32 / Chapter 3.4.3 --- Limitation of GPU --- p.33 / Chapter 3.4.4 --- Input and Output --- p.34 / Chapter 3.4.5 --- Data Readback --- p.34 / Chapter 3.4.6 --- FramebufFer --- p.34 / Chapter 3.5 --- Summary --- p.35 / Chapter 4 --- Volume Rendering --- p.37 / Chapter 4.1 --- Introduction --- p.37 / Chapter 4.2 --- History of Volume Rendering --- p.38 / Chapter 4.3 --- Hardware Accelerated Volume Rendering --- p.40 / Chapter 4.3.1 --- Hardware Acceleration Volume Rendering Methods --- p.41 / Chapter 4.3.2 --- Proxy Geometry --- p.42 / Chapter 4.3.3 --- Object-Aligned Slicing --- p.43 / Chapter 4.3.4 --- View-Aligned Slicing --- p.45 / Chapter 4.4 --- Summary --- p.48 / Chapter 5 --- GPU-Friendly Marching Cubes --- p.49 / Chapter 5.1 --- Introduction --- p.49 / Chapter 5.2 --- Previous Work --- p.50 / Chapter 5.3 --- Traditional Method --- p.52 / Chapter 5.3.1 --- Scalar Volume Data --- p.53 / Chapter 5.3.2 --- Isosurface Extraction --- p.53 / Chapter 5.3.3 --- Flow Chart --- p.54 / Chapter 5.3.4 --- Transparent Isosurfaces --- p.56 / Chapter 5.4 --- Our Method --- p.56 / Chapter 5.4.1 --- Cell Selection --- p.59 / Chapter 5.4.2 --- Vertex Labeling --- p.61 / Chapter 5.4.3 --- Cell Indexing --- p.62 / Chapter 5.4.4 --- Interpolation --- p.65 / Chapter 5.5 --- Rendering Translucent Isosurfaces --- p.67 / Chapter 5.6 --- Implementation and Results --- p.69 / Chapter 5.7 --- Summary --- p.74 / Chapter 6 --- Conclusion --- p.76 / Bibliography --- p.77

Analysis and visualization of large data sets is time consuming and sometimes can be a very difficult process, especially for 3D data sets. Therefore, data processing and visualization techniques have often been used in the case of different massive data analysis for efficiency and accuracy purposes. This thesis presents a multi-scale data sketching solution, specifically for large 3D scientific data with a goal to support collaborative data management, analysis and visualization. The idea is to allow users to quickly identify interesting regions and observe significant patterns without directly accessing the raw data, since most of the information in raw form is not useful. This solution will provide a fast way to allow the users to choose the regions they are interested and save time. By preprocessing the data, our solution can sketch out the general regions of the 3D data, and users can decide whether they are interested in going further to analyze the current data. The key issue is to find efficient and accurate algorithms to detect boundaries or regions information for large 3D scientific data. Specific techniques and performance analysis are also discussed.

Att identifiera vad användare värderar är nyckeln till att företag kan skapa konkurrenskraftiga fördelar. Trots detta använder designers inom området för service design flera visualiseringstekniker som stöd för att visualisera olika aspekter av en service men ingen av visualiseringsteknikerna stödjer en servicedesigner att identifiera vad användare värderar. Utifrån en explorativ metodansats triangulerar studien en enkätundersökning och intervju med en sammanställning av de viktigaste ”ingredienserna” som bör finnas i en visualiseringsteknik som stödjer servicedesigners att identifiera potentiellt användarvärde innan en service är skapad. Resultatet av studien presenteras i form av visualiseringstekniken ”Värdeprofilens resa” som syftar till att stödja designers och företag att uppnå konkurrenskraftiga fördelar genom att identifiera potentiellt användarvärde genom service design. Genom att besvara frågeställningen kan studien möta den problematik som relaterar till avsaknaden av ett visualiseringsstöd som stödjer företags behov av att samla in kunskap om vilken typ av service som kan skapa värde hos användare utan att utgå från en befintlig service. Resultatet av examensarbetet är tänkt att kunna användas av servicedesigners för att identifiera aktiviteter i använ­dares liv där företag, genom sina resurser, kan skapa service som stödjer användares behov och på så sätt skapar användarvärde. / To identify what users value, is the key to business for creating competitive advantages. Despite this, designers in the field of service design using several visualization techniques for support when visualizing different aspects of a service. But none of the visualization techniques support the servicedesigner to identify what the user values. The study is based on a exploratory methodology which triangulates, a questionnaire and interview with a summary of the most important "ingredients" that should be included in visualization technology wich supports servicedesigners to identify potential user value before a service is created. The results of the study are presented in the form of the visualization technique "Value Profile Journey" that aimes to support servicedesigners and companies to whom want to achieve competitive advantage by identifying potential user value through service design. By answering the question the study can face the problems related to the lack of visual aid that supports the company's need to gather knowledge about the type of service that can create user without having to source that from an existing service. The result of this study is meant to be used by servicedesigners to identify activities in the users life in which companies, through their resources, can create services that support users needs and thereby create more value for the users.

Learning disability affects many learners in South Africa and its impact is exacerbated by environmental disadvantage. In a fast changing educational system within a framework of Outcomes-Based Education, where inclusion of learners from various cultures who face a wide variety of barriers to learning is a reality, the need for more accommodating teaching aids and techniques is pressing. Reading comprehension skills influence most aspects of school work, cognitively, emotionally and socially, and therefore learning support strategies to address reading difficulty are especially important. This research focused on visualization as a metacognitive reading comprehension technique for learning support to intermediate level learners with learning disabilities who suffer environmental deprivation. The aim was to help learners to develop and utilise their cognitive skills when reading by forming a mental picture of the text that is being read. Internalization and generalization of this technique was targeted. The communicative meaning of text, rather than fluent word recognition, was emphasized. Manifestations of learning disability, environmental deprivation, problems in reading comprehension and visualization as a "whole brain" approach to reading development were reviewed in the literature. In collaboration with a multicultural school for learners with epilepsy and learning disabilities, the visualization technique was formatively refined during ten sessions of practical implementation. Qualitative and quantitative techniques were used to assess behaviour and performance per learner. Clinical assessments verified the findings of the case studies. / Dissertation (MEd)--University of Pretoria, 2012. / Educational Psychology / unrestricted

En este estudio se han construido dos diferentes instalaciones para investigar primero los chorros de gas horizontales y en segundo lugar los chorros verticales de agua que impactan sobre superficies libres de fluido, también se ha desarrollado un modelo numérico integral para predecir las trayectorias de estos jets y sus parámetros más importantes, validándose con los resultados experimentales obtenidos. En la primera parte de este trabajo, se han realizado experimentos para investigar el comportamiento de chorros de gas horizontales penetrando en agua. Los resultados experimentales indicaron que la longitud de penetración de los chorros de gas está fuertemente influenciada por el diámetro de la boquilla y el número de Froude, así como con el flujo de masa de de entrada y su momento. Aumentar el número de Froude y el diámetro del inyector lleva a aumentar la inestabilidad de jet. Además, la máxima ubicación antes de jet pinch-off se muestra que mantiene una relación logarítmica con el número de Froude para todos los diámetros de jet. Se han desarrollado correlaciones empíricas para predecir estos parámetros. Se ha desarrollado un modelo basado en la integración de las ecuaciones de conservación para que resulte útil en el diseño de aplicaciones en las que participen chorros horizontales así como para asistir a la investigación experimental. Las predicciones del modelo integral se comparan con los datos de los datos experimentales obtenidos con muy buenos resultados. En la segunda parte de este trabajo, se realizaron una serie de experimentos con de chorros de agua, inyectados verticalmente hacia abajo, a través de toberas circulares que impactan sobre una superficie de agua. Los resultados obtenidos mostraron que la profundidad de penetración de la burbuja disminuye con la longitud del chorro, pero que después de ciertas condiciones se mantiene casi constante. Además ésta aumenta con los diámetros de la boquilla y la velocidad del chorro. La velocidad de arrastre / Harby Mohamed Abd Alaal, K. (2012). Experimental and Theoretical Study of the Characteristics of Submerged Horizontal Gas Jets and Vertical Plunging Water Jets in Water Ambient [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/18065