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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.
1

Geovisualization: a framework and case-study analysis for effective climate related visualization

Goudine, Alexei 05 May 2021 (has links)
The impacts of climate change have resulted in the need for adaptation tools to provide stakeholders with the ability to respond to a broad range of potential impacts. Geovisualizations serve as powerful engagement tools due to their capacity in communicating complex climate data to various audiences. Studies have shown a preference towards conveying climate data through geo-visual representations, to quickly present ideas rooted in geographical challenges and solutions. However, a rapid pace of technological advancements has paved the way for an abundance of geovisualization products that have eclipsed the necessary theoretical inquiry and knowledge required to establish effective visualization principles. This study addresses this research gap by conducting a structured review of the geovisualization for climate change literature, and creating a conceptual framework that classifies existing geovisualization products into themes relating to visualization features, audiences, and the intended outcome or purpose of the visualization medium. The Climate Visualizations for Adaptation Products (CVAP) framework, is a tool for researchers and practitioners to use as a decision support system to discern an appropriate type of geovisualization product to implement within a specific use case or towards a particular audience. The process of developing a geovisualization software tool for displaying sea ice probability (SIP) in Arctic regions is detailed, in the context of suggested best practices for web development. Challenges and opportunities encountered while adhering to the best practice protocols and guidelines are examined. A usability evaluation is suggested to assess the general user attitude towards a website or service. Finally a summary with conclusions and suggestions for future research are provided. / Graduate
2

Comparing Different Levels of Interactivity in the Visualization of Spatio-Temporal Data

Ebinger, Samara 10 August 2005 (has links)
The Internet and other advances in technology have dramatically affected cartography in recent decades and yet these new capabilities have not been adequately evaluated for effectiveness. Are dynamic maps more effective than traditional static paper maps in allowing users to visualize spatio-temporal patterns? How important is a higher level of interactivity in visualizing data? Which format is preferred? To examine these questions, human subject tests were conducted to evaluate different levels of interactivity as represented by 1) a static paper map series; 2) an animated map with 'VCR'-type controls; and 3) a toggle map featuring an interactive temporal legend. Results indicate that while the level of interactivity did not affect accuracy of answers to questions regarding spatio-temporal patterns, the total amount of time in which these questions were answered lessened as the level of interactivity increased. Overall, test subjects were more enthusiastic towards the tools featuring greater interactivity.
3

GeoAnalys i Flashmiljö / GeoAnalytics using Flash

Krig, Gunnar January 2009 (has links)
<p><p>There exists a great need among companies and other organizations to be able to visualize statistics. It’s also increasingly common to ask for web-based solutions for increased flexibility and accessibility for users. This paper describes how large amounts of geovisual data, for a large number of regions, can be visualized in an interactive and well-presented manner. The paper let’s you walk through two application scenarios, developed in a Flash environment, using the GeoViz component library for visualization.</p><p> </p><p>The first application has been developed for Statistics Sweden (SCB), to give a solution on how to visualize statistics for Sweden’s zip code regions. The number of zip code regions, a total of 9019, is too high to be able to visualize with today’s computers. This paper gives an example of a solution to this problem, where the regions are being split up according to their respective counties and one county is visualized at a time. The user may freely switch between the different counties, to be able to access statistics for the whole of Sweden.</p><p> </p><p>The second application scenario is a prototype for a road weather prediction system, developed at SMHI for The Swedish Road Administration. They have about 750 weather stations placed along the roads of Sweden, continuously monitoring and reporting road- and weather conditions. Using theses data, together with SMHI:s forecasts, the application may give information on were there is an elevated risk for slippery roads, frost, condensation or strong winds at present time, but also up to 24 hours into the future. The user is given an overview over the status of all stations, but also the possibility to study certain stations in more detail. The application facilitate descision making on, for example, where and when to send out road maintainance vehicles, in good time before the road conditions gets to bad.</p></p>
4

GeoAnalys i Flashmiljö / GeoAnalytics using Flash

Krig, Gunnar January 2009 (has links)
There exists a great need among companies and other organizations to be able to visualize statistics. It’s also increasingly common to ask for web-based solutions for increased flexibility and accessibility for users. This paper describes how large amounts of geovisual data, for a large number of regions, can be visualized in an interactive and well-presented manner. The paper let’s you walk through two application scenarios, developed in a Flash environment, using the GeoViz component library for visualization.   The first application has been developed for Statistics Sweden (SCB), to give a solution on how to visualize statistics for Sweden’s zip code regions. The number of zip code regions, a total of 9019, is too high to be able to visualize with today’s computers. This paper gives an example of a solution to this problem, where the regions are being split up according to their respective counties and one county is visualized at a time. The user may freely switch between the different counties, to be able to access statistics for the whole of Sweden.   The second application scenario is a prototype for a road weather prediction system, developed at SMHI for The Swedish Road Administration. They have about 750 weather stations placed along the roads of Sweden, continuously monitoring and reporting road- and weather conditions. Using theses data, together with SMHI:s forecasts, the application may give information on were there is an elevated risk for slippery roads, frost, condensation or strong winds at present time, but also up to 24 hours into the future. The user is given an overview over the status of all stations, but also the possibility to study certain stations in more detail. The application facilitate descision making on, for example, where and when to send out road maintainance vehicles, in good time before the road conditions gets to bad.
5

Geovisualizing terror: the geography of terrorism threat in the United States

VanHorn, Jason Eugene 23 August 2007 (has links)
No description available.
6

Production, pratique et usages des géovisualisations 3D dans l'aménagement du territoire / Production, pratice and uses of 3D geovizualisation in urban planning

Jacquinod, Florence 16 January 2014 (has links)
Les opportunités en matière de modélisation et de représentation numérique de territoire en 3D sont démultipliées par les évolutions dans les domaines de la cartographie, de l'infographie, de l'animation ou encore de la CAO/DAO. Dans ce contexte de foisonnement technologique, il a été maintes fois constaté un manque crucial d'études empiriques permettant d'évaluer les utilisations de même que les apports et/ou limites des dispositifs géonumériques 3D dans le champ de l'aménagement. C'est pourquoi une enquête ethnographique a été menée. en participant à la production et à l'utilisation de géovisualisations 3D aux côtés d'aménageurs et en contribuant au développement du champ professionnel associé. La participation à l'action permet d'expérimenter différents outils 3D ainsi que d'observer,d' analyser et de documenter leur production, de même que leurs utilisations. par différents acteurs (producteurs,présentateurs, public). Les études de cas menées dans divers contextes (projets routiers, de développement urbains, de parcs éoliens. PPRi. etc.) montrent les utilisations multiples et successives de maintes géovisualisations 3D. Au·delàdes principes de la Grounded Theory mobilisés pour exploiter les données empiriques, l'analyse repose sur le cadrethéorique de l'Actor-Network Theory ainsi que sur la notion d'objet intermédiaire afin de rendre compte des diverses utilisations des géovisualisations 3D, notamment en contexte collectif, collaboratif et de concertation. Au final, ce travail fournit des outils théoriques et des méthodes pour aborder les géovisualisations 3D et leurs usages et propose des pistes pour faire évoluer l'analyse des représentations spatiales. / Opportunities in terms of digital modeling and representation of territories in 3D have risen with the technological developments in the fields of cartography, infographics, animation and CAD. Within this flourishing technological context. the lack of empirical studies ollowing to evaluate the upsides and downsides of the uses of 3D geoferencedmodels has often been highlighted. Hence an ethnographie study has been conducted by participating in the production processes of 3D geovisualisations and contributing to their uses by urban planners as weil as to the development of the''3D" professional field (through communications, formations, articles, etc.). Taking part in planning projects has been used as a way of experimenting. observing, documenting and analyzing the uses of 3D georeferenced models by their producers. presenters and audiences. Case studies in various contexts {urban development, windfarms development, flood mitigation planning. etc.) show that 3D geovisualisations have myriad and heterogeneous uses. Empirical data have been processed using sorne of the Grounded Theory Principles. Actor Network Theory and the notion of "intermediary object'' allow to analyze the uses of 3D geovisualisations in collective and/or collaborative contexts. Finally. theoretical tools and methods to apprehend 3D geovisualisations and their uses are described and new perspectives on how to anlayse spatial representations are opened up.
7

Geovisualization, Geometric Modelling and Displacement Analysis- Applications to Rockslide Investigations

Nordvik, Trond January 2010 (has links)
This thesis addresses different aspects of spatial data handling in connection with investigations of large rockslides. As such, most of the research was carried out in a cross disciplinary and highly applied context. The focus of the thesis is on spatial data handling methodology which directly or indirectly can be used to support in rockslide investigations. Rockslide investigation is a comprehensive term covering all aspects of the evaluation process; from the initial planning of field investigations to data analysis and communication of final results. Central topics addressed in this thesis are; a) How data reduction affect the geometrical accuracy of digital terrain models b) How interactive geometric modelling and geovisualization can be used in complex rockslide investigations and c) How statistical analyses can be used to evaluate displacement measurements of unstable rock slopes. Digital terrain modelling forms an important component of the methodology used for rockslide investigations. The first subtopic addressed in this thesis is related to the construction of Triangulated Irregular Networks (TINs) from Light Detection and Ranging (LIDAR) data. As the LIDAR technology tends to generate large data volumes, the resulting terrain models are generally too large to be efficiently handled by ordinary workstations. Therefore, comparisons of various data reduction (decimation) methods were conducted. Their performances were evaluated by means of deviations from terrain models constructed from full datasets. Evaluation criteria included deviations in volume, surface area and elevation. The results showed that the method using a vertical point selection threshold combined with a data dependent triangulation had the overall best performance when tested on 30 different test datasets. The main objective of the geovisualization part of this thesis was to determine the geometric shapes and locations of potential basal sliding surfaces, for the Åknes rockslide in western Norway, along with the volumes of unstable rock associated with different sliding scenarios. The Åknes rockslide is one of the world's most investigated rockslides due to its potentially catastrophic consequences. A custom written geovisualization application for the Åknes investigation provided the visual context needed for data interpretation and interactive geometric modelling of sliding surfaces. This geovisualization approach enabled geoscientists to develop different sliding scenarios. A scenario putting the basal sliding surface at a depth of 105m to 115m below the topographic surface, delineating an unstable rock volume of 43 million m3, was considered as the most realistic. Statistical approaches for analyzing displacement measurements were also addressed in this thesis. Several methods including regression analysis, spectral analysis and hypothesis testing were demonstrated to measurements obtained from Global Positioning System (GPS), total stations and extensometers at the Åknes rockslide. Displacement measurements obtained from lasers and crackmeters at the Nordnes rockslide in Northern Norway were also analysed. As with the Åknes rockslide, the Nordnes rockslide has the potential for devastating consequences in terms tsunami generation. Consequently, thorough statistical analyses of the available displacement data are crucial in order to obtain accurate estimates for the displacement rates as well as for gaining insight into the sliding processes. Displacement data from both sites clearly showed seasonal variations but the overall long term displacements were regarded constant. Prediction intervals were derived from the current monitoring data from the Nordnes site. These prediction intervals are considered useful for evaluation of future displacement measurements.
8

Content Visualization of GeoAudio Notes

Jusufi, Ilir, Junuzi, Lulzim January 2008 (has links)
<p>The total population of GPS-enabled location-based services (LBS) subscribers is constantly increasing. This fact implies new research possibilities for visualizing geospatial data produced by these mobile devices. The aim of this thesis is to explore novel techniques and methods to visualize the content of voice notes (messages recorded by users on GPS-enabled devices) that will be placed in maps using GPS coordinates, and visualize the semantical, temporal, and spatial relations between the notes. Our research is part of the Geovisualization field which deals with geospatial data.</p><p>Based on our research and analyzes of this problem, we combined different visualization and interaction techniques, thus providing a novel approach to achieve the research aim. We have built a prototype application, called GNV System (GeoAudio Notes Visualization System), that demonstrates our achievements.</p>
9

Content Visualization of GeoAudio Notes

Jusufi, Ilir, Junuzi, Lulzim January 2008 (has links)
The total population of GPS-enabled location-based services (LBS) subscribers is constantly increasing. This fact implies new research possibilities for visualizing geospatial data produced by these mobile devices. The aim of this thesis is to explore novel techniques and methods to visualize the content of voice notes (messages recorded by users on GPS-enabled devices) that will be placed in maps using GPS coordinates, and visualize the semantical, temporal, and spatial relations between the notes. Our research is part of the Geovisualization field which deals with geospatial data. Based on our research and analyzes of this problem, we combined different visualization and interaction techniques, thus providing a novel approach to achieve the research aim. We have built a prototype application, called GNV System (GeoAudio Notes Visualization System), that demonstrates our achievements.
10

Cartogram Visualization: Methods, Applications, and Effectiveness

Nusrat, Sabrina, Nusrat, Sabrina January 2017 (has links)
Cartograms are value-by-area maps which modify geographic regions, such as countries, in proportion to some variable of interest, such as population. These are popular georeferenced data visualizations that have been used for over a century to illustrate patterns and trends in the world around us. A wide variety of cartogram types exist, that were designed to optimize different cartogram dimensions, such as geographic accuracy and statistical accuracy. This work surveys cartogram research in visualization, cartography and geometry, covering a broad spectrum of different cartogram types: from the traditional rectangular cartograms, to Dorling and diffusion cartograms. Based on prior work in visualization and cartography, I propose a task taxonomy of cartograms, and describe a study of cartograms based on quantitative metric-based comparisons, task-based time-and-error evaluation, and subjective preference and feedback analysis. For these evaluations, I considered four major types of cartograms which allowed us to compare and analyze the evaluation strategies and discuss the implications of the surprising outcomes. In the context of maps, the ability to recall information shown in the map is one of the important factors in determining effectiveness. In spite of some early studies that involved cartograms, the memorability of different cartogram types has not been investigated. In order to create effective data presentations, we first need to understand what makes a visualization memorable. I investigate the memorability of contiguous and Dorling cartograms, both in terms of recognition of the map and recall of data. Finally, I describe bivariate cartograms, a technique specifically designed to allow for the simultaneous comparison of two geo-statistical variables. Traditional cartograms are designed to show only a single statistical variable, but in practice, it is often useful to show two variables (e.g., the total sales for two competing companies) simultaneously. Bivariate cartograms make it easy to find geographic patterns and outliers in a pre-attentive way. They are most effective for showing two variables from the same domain (e.g., population in two different years, sales for two different companies), although they can also be used for variables from different domains (e.g., population and income). I also describe a small-scale evaluation of the proposed techniques that indicates bivariate cartograms are especially effective for finding geo-statistical patterns, trends and outliers.

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