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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.
11

Pattern Identification or 3D Visualization? How Best to Learn Topographic Map Comprehension

Atit, Kinnari January 2014 (has links)
Science, Technology, Engineering, and Mathematics (STEM) experts employ many representations that novices find hard to use because they require a critical STEM skill, interpreting two-dimensional (2D) diagrams that represent three-dimensional (3D) information. The current research focuses on learning to interpret topographic maps. Understanding topographic maps requires knowledge of how to interpret the conventions of contour lines, and skill in visualizing that information in 3D (e.g. shape of the terrain). Novices find both tasks difficult. The present study compared two interventions designed to facilitate understanding for topographic maps to minimal text-only instruction. The 3D Visualization group received instruction using 3D gestures and models to help visualize three topographic forms. The Pattern Identification group received instruction using pointing and tracing gestures to help identify the contour patterns associated with the three topographic forms. The Text-based Instruction group received only written instruction explaining topographic maps. All participants then completed a measure of topographic map use. The Pattern Identification group performed better on the map use measure than participants in the Text-based Instruction group, but no significant difference was found between the 3D Visualization group and the other two groups. These results suggest that learning to identify meaningful contour patterns is an effective strategy for learning how to comprehend topographic maps. Future research should address if learning strategies for how to interpret the information represented on a diagram (e.g. identify patterns in the contour lines), before trying to visualize the information in 3D (e.g. visualize the 3D structure of the terrain), also facilitates students' comprehension of other similar types of diagrams. / Psychology
12

Metodologia para controle de qualidade de cartas topográficas digitais / Quality control methodology of digital topographic maps

Inui, Cesar 19 December 2006 (has links)
Hoje, existem muitas empresas de Cartografia que utilizam sistemas CAD para produção de cartas topográficas digitais.Este trabalho tem como proposta a identificação e classificação de erros de atributo gráfico em mapeamento digital, especialmente dados construídos em CAD (Computer Aided Design). Se os dados serão utilizados posteriormente num Sistema de Informações Geográficas, os dados espaciais deverão ser coletados de tal maneira que facilitem a inserção de topologia após a transferência dos dados. Como objetivo secundário, o trabalho propõe um melhor controle de qualidade, demonstrando seqüência lógica de tarefas para revisão e correção de problemas em dados espaciais / There are many Cartography corporations wich use CAD systems to built digital Topographic maps.This research intend to identify and classify errors of graphic attribute in digital mapping, specially digital spactial data built in CAD (Computer Aided Design). If these data will be applied in a Geographic Information System, they must be designed in a way that could easily perform spatial relationships (topology) after the data transfer.As a secondary objective, there is a suggestion of a better data quality control, showing a logical sequence of tasks to check up and correct problems in spatial data
13

A 2D visual language for rapid 3D scene design : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in the University of Canterbury /

Adams, Nathan January 2009 (has links)
Thesis (M. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 82-93). Also available via the World Wide Web.
14

The development of a visualization tool to assist topographic map users

Van den Heever, Johannes Lodewikus 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: The recognition and description of relief features from their contour patterns is recognized as the main challenge in topographic map education. Conducting field exercises can solve this problem, but can be very time consuming. Modern technology, however, provides an alternative teaching technique by creating depictions of terrain. Important issues raised by this new approach include questions such as what these depictions should look like and how it should be presented to the user. Research presented here aims to address these issues by constructing design guidelines for terrain depiction. These design guidelines were derived from previous research and case studies. The guidelines focussed on research about how people perceive different representations of terrain and how these representations should optimally be presented. The design guidelines were constructed from research done in diverse fields such as cognitive psychology, cartography and engineering. Results of this research revealed that in order to develop an effective terrain visualization tool, it is crucial to incorporate different fields of expertise. The design guidelines were implemented with ArcView GIS and its 3D Analyst extension, which has the ability to display spatial data in three dimensions. The final product is called Terrain Visualization Tool 1.1 (TVT) and was created by customizing an ArcView GIS project (TV BUILDER) and constructing a Website (TV VIEWER). TV BUILDER creates the visualization data in the form of 20 web pages per topographic area and links them to TV VIEWER that serves as a platform to view the data. The design guidelines were implemented successfully and show the advantages of using Geographical Information Systems (GIS) in related research. / AFRIKAANSE OPSOMMING: Die identifisering en beskrywing van landskapelemente vanaf hul kontoere is geidentifiseer as die primere uitdaging in topografiese kaartonderrig. Hierdie probleem kan oorkom word deur kaartleesoefeninge in die veld te onderneem, maar dit neem baie tyd in beslag. Modeme tegnologie maak ‘n alternatiewe onderrigmedium moontlik deur die skep van verskillende landskapsuitbeeldings. Hierdie alternatief laat die vraag ontstaan hoe die uitbeeldings moet lyk en hoe dit aan die gebruiker aangebied moet word. Die doel van hierdie navorsing spreek hierdie vrae aan deur ontwerpriglyne vir landskap uitbeelding daar te stel. Die ontwerpriglyne is saamgestel deur bestudering van vorige navorsing en studies wat op hierdie gebied gedoen is. Die riglyne fokus veral op navorsing wat mense se reaksie op verskillende landskapuitbeeldings ondersoek. Die ontwerpriglyne is egter saamgestel deur navorsing wat gedoen is in velde soos kognitiewe sielkunde, kartografie en ingenieurswese. Hierdie navorsing het bewys dat inkorporasie van verskillende studievelde in die ontwikkeling van terrein visualiseringstoepassings essensieel is. Die riglyne is geimplementeer deur gebruik te maak van ArcView GIS en die 3D Analyst uitbreiding wat die vermoe het om data in drie dimensies uit te beeld. Die finale produk genaamd Terrain Visualization Tool 1.1 (TVT) bestaan uit twee komponente, naamlik ‘n aangepaste ArcView GIS projek (TV BUILDER) en ‘n webwerf (TV VIEWER). TV BUILDER skep die landskapsuitbeeldings van een topografiese area in die vorm van 20 web bladsye en verbind dit met TV VIEWER, wat as ‘n platform dien om die landskap uitbeeldings te beskou. Die ontwerpriglyne is suksesvol geimplementeer, wat die voordele van Geografiese Inligtingstelsels (GIS) in hierdie en soortgelyke toekomstige navorsing demonstreer.
15

Metodologia para controle de qualidade de cartas topográficas digitais / Quality control methodology of digital topographic maps

Cesar Inui 19 December 2006 (has links)
Hoje, existem muitas empresas de Cartografia que utilizam sistemas CAD para produção de cartas topográficas digitais.Este trabalho tem como proposta a identificação e classificação de erros de atributo gráfico em mapeamento digital, especialmente dados construídos em CAD (Computer Aided Design). Se os dados serão utilizados posteriormente num Sistema de Informações Geográficas, os dados espaciais deverão ser coletados de tal maneira que facilitem a inserção de topologia após a transferência dos dados. Como objetivo secundário, o trabalho propõe um melhor controle de qualidade, demonstrando seqüência lógica de tarefas para revisão e correção de problemas em dados espaciais / There are many Cartography corporations wich use CAD systems to built digital Topographic maps.This research intend to identify and classify errors of graphic attribute in digital mapping, specially digital spactial data built in CAD (Computer Aided Design). If these data will be applied in a Geographic Information System, they must be designed in a way that could easily perform spatial relationships (topology) after the data transfer.As a secondary objective, there is a suggestion of a better data quality control, showing a logical sequence of tasks to check up and correct problems in spatial data
16

An automated method for locating sinkholes in Montgomery County, Virginia, using digital elevation models

Mehrotra, Neeta 22 August 2009 (has links)
The prospect of using U.S.G.S. Digital Elevation Models (DEM's) to locate sinkholes has been investigated. Three quadrangle maps, those of Blacksburg, Ironto and Newport, were selected as these areas are dotted with sinkholes. An algorithm was developed to extract sinkholes from DEM's. Sinkholes were also digitized from the topographic maps to check the accuracy of those extracted by the program from DEM's. This was done by overlaying pits extracted from DEM's with digitized sinkholes. Discriminant Analysis was run to compare the characteristics of sinkholes identified by the program from those that were not. It was found that few sinkholes could be located using the available integer elevation data of 30m resolution. Noise in the data, even after running a filter, precluded satisfactory results. It was concluded that elevation data of finer resolution and in real format should be used for this analysis. / Master of Science
17

Computational Delineation of Built-up Area at Urban Block Level from Topographic Maps: A Contribution to Retrospective Monitoring of Urban Dynamics

Muhs, Sebastian 20 May 2019 (has links)
Among many others, one general goal of the UN sustainability strategies aims at reducing the anthropogenic land change due to land take for settlements and transport infrastructure. To monitor the success of this goal and to comprehensively study and better understand these urban dynamic processes – such as densification, growth and sprawl, or shrinkage –, quantitative measurements were introduced to assist the assessment. For the analysis of urban dynamics, the built-up area is an important measure that can be considered at different scales, one common scale being the aggregated level of urban blocks that represent a group of developed parcels bounded by topographic borders such as street lines. Regardless of the scale of quantitative analysis, however, digital spatio-temporal data are essential. While comprehensive databases exist for contemporary data, they usually lack a historic dimension. To derive these historic data about the built-up area, potential surveying methods and sources may vary. Considering the long-term characteristic of urban land change, however, topographic maps often are the only source for small-scale, spatially explicit land cover information to build a comprehensive, spatio-temporal database of built-up area, which has been demonstrated by numerous studies. However, the manual constitution of historic geographic data based on historic maps – commonly referred to as map digitization or vectorization – is a time consuming and laborious process that limits the spatial and temporal scope and, therefore, opposes comprehensive studies. Therefore, this thesis proposes an approach to automatically extract information about the built-up area at urban block level from historic topographic maps. For a number of reasons, this is a challenging task. First, topographic maps show a high degree of informational density and complexity due to their layer concept. These layers of geographic objects generally overlap leading to the (multi-)fragmentation or fusion of distinct geographic map objects. While this may not pose a challenge to a human interpreter, it does for the formalization of the computational object recognition. Second, material aging of the document as well as a poor scanning or image compression process may result in a reduced graphical quality. Third, object representations including the use of color, if present at all, show an immense diversity over space and time. To overcome these challenges in regard to cartographical image analysis, a modular process has been designed pursuing a two-step strategy: a decomposition of salient map layers is succeeded by a re-composition of the structuring map objects to delineate the built-up area at urban block level. Several experiments prove this process to achieve acceptable results with correctness values ranging from 0.97 to 0.93 for three German study maps. Behind the background of a global trend to digitize knowledge that can also be observed with historic topographic maps, the designed process represents a promising approach to efficiently prepare these historic data for integration into a spatio-temporal database of built-up area with minimal user intervention.:Declaration of Authorship Acknowledgements Summary Contents List of Figures List of Tables List of Abbreviations 1 Introduction 1.1 Scope 1.2 Challenges 1.3 Research Questions 1.4 Structure 2 Principles of Image Analysis 2.1 Human Visual Perception 2.2 Methods of Image Analyis 2.2.1 Image Segmentation 2.2.1.1 Color Image Segmentation 2.2.1.2 Texture-based Segmentation 2.2.1.3 Morphology-based Segmentation 2.2.1.4 Further Segmentation Approaches 2.2.2 Object/Pattern Recognition 2.2.2.1 Strategies in Pattern Recognition 2.2.2.2 Approaches in Pattern Recognition 2.2.3 Object Reconstruction 2.2.3.1 Reconstruction of Contours 2.2.3.2 Raster-vector Conversion 2.3 Summary 3 Cartographic Image Analysis 3.1 Geoinformation from Cartographic Raster Maps 3.1.1 Raster Maps 3.1.2 Research History 3.1.3 Research – State of the Art 3.1.3.1 Separation of Raster Layers based on Color 3.1.3.2 Extraction and Recognition of Map Objects 3.1.3.3 Automated Georeferencing 3.1.4 Delineation of Built-up Area from Cartographic Raster Maps 3.2 Further Sources for the Delineation of Built-up Area 3.3 Summary and Interim Conclusions 4 Concept and Methodology 4.1 Concept - Preliminary Considerations 4.1.1 Defining the Subject of Delineatoin – the Urban Block 4.1.2 Data Characteristics 4.1.3 Cartographical Representation and Higher-Level Demarcation of Built-up Area 4.2 Methodological Design 4.2.1 Requirements to the Process and the Input Data 4.2.2 General Methodical Approach 4.2.3 Derivation of the General Delineation Process 4.2.4 Module Map Objects 4.2.4.1 Building Symbols 4.2.4.2 Residential Area Hatching 4.2.4.3 Railroads and Tramlines 4.2.5 Module Street Block Delineation 4.2.5.1 Street Network 4.2.5.2 Reconstruction of Street Block Objects 4.2.5.3 Evaluation of Street Block Objects 4.2.6 Delineation of Built-up Area 4.2.6.1 Module Building Grouping 4.2.6.2 Module Built-up Area 4.3 Implementation 5 Evaluation and Discussions 5.1 Evaluation Frameset 5.1.1 Study Maps 5.1.2 Reference Data 5.1.3 Methodology 5.2 Experiments and Results 5.2.1 Experiments 5.2.1.1 E.0 – Delineate Built-up Area Using the General Process 5.2.1.2 E.1 – Delineate Built-up Area Using a Deviation of the General Process 5.2.1.3 E.2 – Delineate Built-up Area Using Maps with Varying Spatial Resolution 5.2.2 Results 5.2.2.1 R.0 – Delineation Results of the General Process 5.2.2.2 R.1 – Delineation Results of the Deviated Process Variants 5.2.2.3 R.2 – Delineation Results of the Deviated Map Resolution Variants 5.3 Discussions 5.3.1 Strengths and Limitations 5.3.2 Comparision of Delineation Results to other Studies 5.3.3 Applications and Transferability to other Maps 6 Conclusion and Outlook 6.1 Revising the Research Questions 6.2 Scientific Contribution 6.3 Future Research Perspectives References Appendix A.1 List of Process Parameters and their Application A.2 Exemplary Delineation Results
18

Επιπτώσεις και αποτελέσματα από την ανθρώπινη παρέμβαση στις μορφογενετικές διεργασίες στον κάτω ρου τού Αλφειού ποταμού

Αλεβίζος, Γιώργος 08 July 2011 (has links)
Η παρούσα εργασία πραγματοποιήθηκε στον Τομέα Γενικής Θαλάσσιας Γεωλογίας και Γεωδυναμικής του Τμήματος Γεωλογίας του Πανεπιστημίου Πατρών. Στο πλαίσιο αυτής, μελετήθηκε ο κάτω ρους του Αλφειού ποταμού και η μορφολογική του εξέλιξη, σε συνδυασμό με τις ανθρώπινες παρεμβάσεις. Σκοπός της εργασίας αυτής είναι η παρουσίαση, η ανάλυση, ο σχολιασμός και η αξιολόγηση των αλλαγών στο που έχει υποστεί ο κάτω ρους του ποταμού. Η εν λόγω περιοχή παρουσιάζει αξιόλογο ενδιαφέρον λόγω των ιδιαίτερων και σύνθετων μορφοκλιματικών συνθηκών που επικρατούν, των τεχνικών έργων της περιοχής και γενικά των επιδράσεων που είναι αποτέλεσμα κυρίως της ολοένα και αυξανόμενης ανθρώπινης παρέμβασης. / This diploma thesis was conducted at the General Department of Marine Geology and Geodynamics, Department of Geology, University of Patras. As part of this work, it was studied the lower weight of the Alfeios River and the morphological evolution, combined with human intervention. The purpose of this work is the presentation, analysis, commentary and evaluation of changes on the lower watercourse of Alfeios river. This area presents considerable interest because of the special and complex morphocimate conditions,the technical projects in the area and generally the effects which are mainly the result of ever-increasing human intervention.
19

Εφαρμογή Γεωγραφικών Συστημάτων Πληροφοριών (GIS) για την αποτύπωση της θαλάσσιας ρύπανσης στην περιοχή του κόλπου του Αλιβερίου

Παπαμιτσάκη, Ελένη 15 February 2012 (has links)
Το Αλιβέρι είναι μια κωμόπολη της Εύβοιας. Βρίσκεται λίγα χιλιόμετρα νοτιοανατολικά της Χαλκίδας και βρέχεται από τα νερά του Ευβοϊκού Kόλπου. Είναι μια περιοχή περιβαλλοντικού ενδιαφέροντος εφόσον λειτουργούν στην παράκτια περιοχή θερμικός σταθμός ηλεκτροπαραγωγής της Δ.Ε.Η. και μια τσιμεντοβιομηχανία (Α.Γ.Ε.Τ.), από τις οποίες είτε αποτίθεται τέφρα κοντά στη θάλασσα είτε διαφεύγουν αέριοι ρύποι από τις καμινάδες. Στόχος της εργασίας είναι να γίνει ψηφιοποίηση τοπογραφικών και γεωγραφικών χαρτών κλίμακας 1:50.000 και να αποτυπωθούν δεδομένα από μετρήσεις που έγιναν σε δείγματα που έχουν ήδη ληφθεί από το θαλάσσιο περιβάλλον. Οι μετρήσεις αυτές αφορούν ρύπανση από μέταλλα. / Aliveri is a town on the island of Evoia, located a few kilometers southwest of Chalkida and watered by Evoian Gulf. It is an area of high environmental importance because of the operation at its coastal area of a thermal power plant operated by the Public Power Corporation (PPC) S.A and the cement manufacturing industry (AGET), from which either ash is stockpiled near the sea coast, or air pollutants are emitted from the chimneys. The aim of the study is to digitize the topographic maps (scale 1:50.000) and to depict data from measurements carried out on samples already taken from the marine environment. These measurements are related to metal pollution. The results include a database where we can build further studies and tracking trends in terms of the outfall and the dispersion of pollutants in the marine environment and attempts to determine the source of the metal pollution through geographical maps.
20

Connaissances pour la conception et la perception de styles topographiques / Knowledge on the design and the perception of topographic styles

Ory, Jérémie 02 December 2016 (has links)
La conception de cartes topographiques de référence est aujourd’hui caractérisée par une multiplication des données géographiques et des services de conception cartographiques de plus en plus distribués. Dans ce contexte, il est nécessaire d’enrichir les connaissances existantes sur la rédaction cartographique afin de préserver la qualité des cartes produites, i.e. qu’elles soient lisibles et efficaces. Nous faisons l’hypothèse que le style topographique facilite la lisibilité et l’efficacité d’une carte grâce à des codes et repères visuels connus des utilisateurs. Nous nous sommes fixés comme objectif de formaliser la notion de style topographique en tant que famille cartographique regroupant des signes graphiques reconnus des utilisateurs afin de pouvoir l’utiliser pour produire de nouvelles cartes topographiques.Dans ce travail de thèse, nous proposons un modèle conceptuel intégrant les concepts clés de signature visuelle et de famille cartographique. Nous validons et instancions ce modèle à travers la mise en place d’entretiens auprès d’experts cartographes et le déploiement de deux expérimentations auprès d’utilisateurs permettant d’étudier les familles cartographiques IGN et Swisstopo. Les résultats obtenus permettent de caractériser les signatures visuelles de chacune de ces deux familles cartographiques. À l’aide de la caractérisation des signatures visuelles de ces deux styles topographiques typiques (IGN-France et Swisstopo), nous proposons des recommandations qui permettraient de produire de nouvelles cartes topographiques pour les deux cas d’application suivants : (1) produire de nouvelles cartes topographiques appartenant au même style topographique, (2) produire de nouvelles cartes topographiques à la frontière entre deux pays / agences nationales de cartographie / The design of topographic maps of reference is characterised both by an increasing amount of reference geographic databases and by design geo-services operating in distributed architectures. In this context, one of the major challenges consists in enriching the current knowledge on cartographic design in order to preserve the maps quality, i.e. they are legible, effective and usable. We assume that the topographic style renders maps legible and effective thanks to the visual codes and guides, well-known by the users. Our research purpose aims at formalising the concept of a topographic style as a cartographic family with a recognizable visual signature in order to produce new topographic maps.We propose to formalize key concepts of visual signature and cartographic family in a unified model. We validate and instantiate this model in setting up interviews of cartography experts and in designing user’s experiments allowing to evaluate the visual recognition of maps and graphic signs belonging in Swisstopo and IGN-France cartographic families. With results of the two user’s experiments, we characterize the visual signature of the two cartographic families. Then, we propose cartographic design guidelines in order to produce reference topographic maps based on the characterisation of the visual signature for two cases studies: (1) design a map belonging in a given cartographic family, (2) design a map on the border of two countries / two national mapping agencies

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