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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.
31

Multi-spectral image segmentation and compression

Martin, Ian John January 1999 (has links)
No description available.
32

Chromo-stereoscopic visualisation for dynamic marine operations

Abdel Hamid, Iman January 2012 (has links)
Chromo stereoscopy (CS) is a simple and cost effective 3D system that can easily deliver geospatial information. CS has been used in several scientific data presentations, including remote sensing, physical modelling and hydrographic applications. In some of these applications the 3D effect was solely CS-related, while others integrated CS with other methods of implementing 3D. CS was mainly used in static visualisation, but no dynamic applications were found. Also, the restricted use of colour was acknowledged as a limitation for CS suggesting its unsuitability for applications where colour conventions are significant. This research focuses on CS for the marine applications and aims to (i) investigate users’ perception to CS effect and its interaction with other depth cues, (ii) assess the acceptance of the potential users to the changes in conventional colouring systems, (iii) and evaluate the usability and practicality of CS as an additional visualisation system in dynamic marine applications. To address these, visual scenarios were developed and expert human participants were recruited and interview for the evaluation. CS was well perceived among the participants. The interaction between different depth cues has advantages of increasing the depth perception and comprehending the 3D nature of the surrounding environment. For instance, from a certain view angle where two objects block each other, CS enhances the interposition effect, that indicates which object is in the front and gives a qualitative estimation of the spatial separation between them. Shading increases the realism of surface objects, and provides information for their undulation. It also dilutes the colours used in CS and increases the range of colours perceived and enhances the effect perceived from CS. The advantage of using the colour coding system to indicate distance is a valuable and original outcome of this thesis. This coding improved the participants understanding of the behaviour of moving objects (whether vessels coming closer or drifting apart) and enabled users to locate them in reference to the surrounding topography. Such knowledge is important to attain safer operations in a 3D environment. Accepting changes in colours in a visual presentation is linked to experience gained during interaction with the system, and the changes would be tolerated by the users in favour of improvements in situation awareness. Blind navigation and underwater operations are examples of where CS can be beneficial.
33

Flow visualisation by means of Electronic Speckle Pattern Interferometry (ESPI)

Michal, Eli 09 April 2008 (has links)
Abstract This research report details the design, construction, implementation and optimization of a quantitative movable flow visualization technique named Electronic Speckle Pattern Interferometry (ESPI). ESPI is a powerful visualisation technique that can allow for full flowfield analysis. It is thus possible to quantitatively determine the refractive index variation and hence the density variation in a compressible gas flow. Complementary results between previous work done and the current work shows the integrity of ESPI results Flowfields that were investigated included – candle flame, axis symmetric and nonaxis symmetric nozzles. Due to advanced CCD technology, there have been improvements in the overall image quality. Post processing of the images produced clearer images and hence better results. The technique was applied on multiple test rigs, proving its versatility
34

Encircling the land: photographic visualisations of the experience of a landscape

Sher, Hilton Stanley 21 June 2012 (has links)
This project documents my process of visual and hermeneutic enquiry centred on the Tswaing meteorite impact crater, north of Pretoria. In my visual investigation I attempt to apprehend the landscape through a cyclical process which involves walking within it, photographing it in 360° ‘visualisations’, editing the imagery and returning, often frustrated, to repeat both encounter and process. The cycle of reflection leads me to consider my circular process itself as a dialogical mode of interpretation and response to the primeval, circular landscape of the impact crater. Informed by Gadamer’s (1975) notion of a hermeneutic circle which extends interpretation and understanding, the reflexive process is extended and enriched through dialogue with the work of pertinent scientists, artists, poets and writers. Landscape is considered as an artefact of deep time, challenging entrenched traditions and notions while considering significant contemporary responses. The dissertation attempts to demonstrate the layered accretion of concept and meaning contained within the visual and theoretical components of the investigation
35

Visualising Plasmodium falciparum functional genomic data in MaGnET : malaria genome exploration tool

Sharman, Joanna Louise January 2009 (has links)
Malaria affects the lives of 500 million people around the world each year. The disease is caused by protozoan parasites of the genus Plasmodium, whose ability to evade the immune system and quickly evolve resistance to drugs poses a major challenge for disease control. The results of several Plasmodium genome sequencing projects have revealed how little is known about the function of their genes (over half of the approximately 5400 genes in Plasmodium falciparum, the most deadly human parasite, are annotated as hypothetical ). Recently, several large-scale studies have attempted to shed light on the processes in which genes are involved; for example, the use of DNA microarrays to profile the parasite s gene expression. With the emergence of varied types of functional genomic data comes a need for effective tools that allow biologists (and bioinformaticians) to explore these data. The goal of exploration/browsing-style analyses will typically be to derive clues towards the function of thus far uncharacterised gene products, and to formulate experimentally testable hypotheses. Graphic interfaces to individual data sets are obviously beneficial in this endeavour. However, effective visual data exploration requires also that interfaces to different functional genomic data are integrated and that the user can carry forward a selected group of genes (not merely one at a time) across a variety of data sets. Non-expert users especially benefit from workbenchlike tools offering access to the data in this way. Still, only very few of the contemporary publicly available software have implemented such functionality. This work introduces a novel software tool for the integrated visualisation of functional genomic data relating to P. falciparum: the Malaria Genome Exploration Tool (MaGnET). MaGnET consists of a light-weight Java program for effective visualisation linked to a MySQL database for data storage. In order to maximise accessibility, the program is publicly available over the World Wide Web (http://www.malariagenomeexplorer.org/). MaGnET incorporates a Genome Viewer for visualising the location of genomic features, a Protein-Protein Interaction Viewer for visualising networks of experimentally determined interactions and an Expression Data Viewer for displaying mRNA and protein expression data. Complex database queries can easily be constructed in the Data Analysis Viewer. An advantage over most other tools is that all sections are fully integrated, allowing users to carry selected groups of genes across different datasets. Furthermore, MaGnET provides useful advanced visualisation features, including mapping of expression data onto genomic location or protein-protein interaction network. The inclusion of available third-party Java software has expanded the visualisation capability of MaGnET; for example, the Jmol viewer has been incorporated for viewing 3-D protein structures. An effort has been made to only include data in MaGnET that is at least of reasonable quality. The MaGnET database collates experimental data from various public Plasmodium resources (e.g. PlasmoDB) and from published functional genomic studies, such as DNA microarrays. In addition, through careful filtering and labelling we have been able to include some predicted annotation that has not been experimentally confirmed, such as Gene Ontology and InterPro functional assignments and modelled protein structures. The application of MaGnET to malaria biology is demonstrated through a series of small studies. Initial examples show how MaGnET can be used to effectively demonstrate results from previously published analyses. This is followed up by using MaGnET to make a set of predictions about the possible functions of selected uncharacterised genes and suggesting follow-up experiments.
36

3D visualisation of historic and environmentally significant shipwrecks : the development of occlusion objects, Locoramps and digital cinematography

Rowland, Chris January 2010 (has links)
This thesis explores the hypothesis that current industry standard methods used to visualise environmentally hazardous or historically significant shipwrecks can be improved by adopting a number of new, aesthetically considered, methods. The thesis describes the development of occlusion objects, locoramps and the use of digital cinematography, as methods that the author proposes to improve the 3D visualisation of point cloud data from multibeam sonar. Case studies were selected as the basis for experimentation; they include HMS Royal Oak in Orkney and SS Richard Montgomery in the Thames Estuary. The author collaborated with a multi-disciplinary team of forensic maritime archaeologists, marine surveyors and salvage experts to gain access to unique shipwreck sites and the high resolution sonar data gathered from them. Through experimentation with the data, occlusion objects, locally oriented colour ramps (locoramps) and improved depth cueing through digital cinematography were developed and applied in 3D visualisations of the case study wrecks. A real-time application WreckSight was created to exploit the new methods. The resulting 3D visualisations of the wrecks were evaluated by a number of target audience groups by means of an interactive questionnaire that allows a direct comparison of data presented using the new methods with traditional display methods. Analysis of the resulting data shows a statistical significance that supports the hypothesis. The author proposes that the new methods constitute new knowledge in the 3D visualisation of multibeam sonar data of shipwrecks.
37

A study of large-scale focusing Schlieren systems

Goulding, John Stuart 19 May 2008 (has links)
Abstract The interrelationship between variables involved in focusing schlieren systems is fairly well understood, however how changing the variables affects the resultant images is not. In addition, modified grids and arrangements, such as two dimensional, colour and retroreflective systems have never been directly compared to a standard system. The existing theory is developed from first principles to its current state. An apparatus was specifically designed to test grid and arrangement issues while keeping the system geometry, optical components and the test object identical. Source grid line spacing and clear line width to dark line width ratio were varied to investigate the limits of diffraction and banding and to find an optimum grid for this apparatus. Two dimensional, colour, retroreflective and a novel projected arrangement were then compared to this optimum case. In conclusion, the diffraction limit is accurately modelled by the mathematical equations. The banding limit is slightly less well modelled as additional factors seem to affect the final image. Inherent problems with the two dimensional and colour systems indicate that while they can be useful, they are not worth developing further though chromatism in the system meant that colour systems were not fully investigated. The retroreflective and projected systems have the most potential for large scale use and should be developed further.
38

Détection des galaxies à faible brillance de surface, segmentation hyperspectrale dans le cadre de l'observatoire virtuel

Petremand, Matthieu Collet, Christophe Genova, Françoise January 2007 (has links) (PDF)
Thèse doctorat : Informatique. Traitement d'Images et Vision par Ordinateur : Strasbourg 1 : 2006. / Titre provenant de l'écran-titre. Bibliogr. 5 p.
39

Visualisation of requirements and their relations in embedded systems

Lööf, Robert, Pussinen, Kenny January 2014 (has links)
In the automotive industry, the complexity of electronic components is increasing rapidly. Modern functional safety standards rely on strict requirements engineering techniques in order to ensure the safety of a given system. Current requirements management tools on the market either suffer in their ability to handle such constraints or are not susceptible to industrial applicability. To solve this problem, two main questions have been focused in this master thesis. How to visualise the requirements and their relationship to architecture and how to provide a solution that reflects on how work is conducted today at Scania. A prototype with focus on visualisation of requirements and their relationship to architectures has been developed. To provide an intuitive solution that reflects on how work is conducted, an evaluation of the prototype has been conducted. The prototype was evaluated by engineers at Scania that works with requirements in their daily work. The conclusion of the evaluation suggests that visualisation of requirements and their relation to architecture could be beneficial for requirement engineering. To keep the solution intuitive it is important to focus on filtering methods for the visualisation in future development.
40

Stratigraphic visualisation for archaeological investigation

Green, Damian Alan January 2003 (has links)
The principal objective of archaeology is to reconstruct in all possible ways the life of a community at a specific physical location throughout a specific time period. Distinctly separate layers of soil provide evidence for a specific time period. Discovered artefacts are most frequently used to date the layer. An artefact taken out of context is virtually worthless; hence the correct registration of the layer in which they were uncovered is of great importance. The most popular way to record temporal relationships between stratigraphic layers is through the use of the 2D Harris Matrix method. Without accurate 3D spatial recording of the layers, it is difficult if not impossible, to form new stratigraphic correspondences or correlations. New techniques for archaeological recording, reconstruction, visualisation and interpretation in 3D space are described in these works and as a result software has been developed. Within the developed software system, legacy stratigraphy data, reconstructed from archaeological notebooks can be integrated with contemporary photogrammetric models and theodolite point data representations to provide as comprehensive a reconstruction as possible. The new methods developed from this research have the capability to illustrate the progression of the excavation over time. This is made possible after the entry of only two or more strata. Sophisticated, yet easy-to-use tools allow the navigation of the entire site in 3D. Through the use of an animation-bar it is possible to replay through time both the excavation period and the occupation period, that is to say the various time periods in antiquity when human beings occupied these locations. The lack of complete and consistent recording of the soil layers was an issue that proved to be an obstacle for complete reconstruction during the development of these methods. A lack of worldwide archaeological consensus on the methods of stratigraphic recording inhibited development of a universal scientific tool. As a result, new recording methods are suggested to allow more scientific stratigraphic reconstruction.

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