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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.
241

Planar segmentation for Geometric Reverse Engineering using data from a laser profile scanner mounted on an industrial robot

Rahayem, Mohamed January 2008 (has links)
Laser scanners in combination with devices for accurate orientation like Coordinate Measuring Machines (CMM) are often used in Geometric Reverse Engineering (GRE) to measure point data. The industrial robot as a device for orientation has relatively low accuracy but the advantage of being numerically controlled, fast, flexible, rather cheap and compatible with industrial environments. It is therefore of interest to investigate if it can be used in this application. This thesis will describe a measuring system consisting of a laser profile scanner mounted on an industrial robot with a turntable. It will also give an introduction to Geometric Reverse Engineering (GRE) and describe an automatic GRE process using this measuring system. The thesis also presents a detailed accuracy analysis supported by experiments that show how 2D profile data can be used to achieve a higher accuracy than the basic accuracy of the robot. The core topic of the thesis is the investigation of a new technique for planar segmentation. The new method is implemented in the GRE system and compared with an implementation of a more traditional method. Results from practical experiments show that the new method is much faster while equally accurate or better.
242

Der Geophilus Bodenprofilscanner

Rühlmann, Jörg, Meyer, Swen 14 November 2017 (has links) (PDF)
No description available.
243

Architecture et cartographie à la lumière du numérique : naissance du Système d’information géographique du Canada

Kowal, Stephan 12 1900 (has links)
Le sujet principal de cette thèse est le développement du Système d’information géographique du Canada à partir de 1962, permettant de combiner des informations statistiques et des documents cartographiques, spécifiquement dans le but d’aider à la prise de décision dans la planification du territoire. La recherche revisite le contexte politique et économique menant au développement du premier système de ce type autour du programme gouvernemental pour l’inventaire des terres du Canada, le Canada Land Inventory (CLI), issu de la Loi sur la remise en valeur et l’aménagement des terres agricoles (ARDA) puis de sa modification pour inclure tout l’aménagement rural, établissant des relations entre des sociétés privées (Spartan Air Services, Canada et IBM Canada) et des chercheurs universitaires. La recherche présente des documents de la Bibliothèque et Archives Canada. C’est la nature cartographique de ce système développé au Canada et le transfert de cartes dessinées à la main dans un format numérique, par l’entremise du système binaire, qui fournissent de nouvelles idées sur des changements importants concernant la théorie de la représentation conventionnelle. Par le biais de lectures attentives de ces instruments de transcription automatique et non automatique développés à la fin des années 1950 et au début des années 1960, et, plus précisément, par le développement d’un dispositif spécialement conçu pour ce système, le Special Cartographic Scanner, la thèse traite de la transition depuis des cartes dessinées manuellement à des bases de données manipulables : elle examine la nature des informations cartographiques en termes du point, de la ligne, de la surface, de l’échelle et du cadrage, bouleversant certaines notions de la projection conventionnelle dans la représentation, par l’entremise de la procédure de numérisation, du développement d’une nouvelle technique de séquençage des fichiers, de l’introduction d’un système de coordonnées de référence, de régions de données traitables, de leurs superpositions. La thèse démontre que les notions de position, de ligne et de cadre dans la représentation traditionnelle ont changé, au profit du point numérique et de la sélection. Dans une volonté de relier la cartographie numérique à la conception en architecture, la thèse exemplifie la transition de la représentation développée depuis la Renaissance autour de l’œil, à l’usage d’instruments de télédétection et dans des images générées par des ordinateurs, et de la recherche de patterns, influençant l’approche dans la prise de décision et la conception, par la capacité du système à générer de nouvelles connaissances par la superposition et la combinaison d’éléments ponctuels. La thèse situe le Système d’information géographique du Canada dans le contexte de la cybernétique et des théories de l’information, pour le positionner dans la théorie de la concrétisation des objets techniques du philosophe Gilbert Simondon, puis à sa théorie des points-clefs, auxquels sont rattachés les objets techniques dans le territoire, considéré comme subjectif et une production esthétique. / The main topic of this thesis is the development of the Canada Geographic Information System (CGIS) initiated in 1962, an integrated computer system capable of combining national statistical information and cartographic documents, specifically intended for decision-making in regional planning. The text revisits the political and economic context leading to the development of the first system of this type, arising from the Canada Land Inventory (CLI), a government program stemming from the Agricultural Rehabilitation and Development Act (ARDA), which was expanded to include all rural development. It establishes relations between the CLI and private companies (Spartan Air Services, Canada and IBM Canada) and scholars. This research presents material from the Library and Archives Canada. It is the cartographic nature of this system developed in Canada, and the transfer of hand-drawn cartographic documents into a digital format through the binary system, which provides renewed insights into important changes concerning conventional representation theory. Through close examination of these automatic and non-automatic transcription devices developed in the 1950s and 1960s, and more precisely, through the development of a device specifically designed for this system, the Special Cartographic Scanner, this text deals with the transition from hand-drawn maps to manipulable digital databases. This thesis examines the nature of cartographic information in terms of point, line, surface, scale and frame, disrupting certain conventions of representation and drawing, through digitising procedures, as well as a new technique of sequencing files, the introduction of the world’s coordinate system, regions of processable data, and their overlay. This thesis demonstrates that notions of position, line and frame in conventional representation have changed for the benefit of a digital point and selection. In an effort to link digital cartography to architectural design, this thesis exemplifies the transition from representations based on the human eye, developed since the Renaissance, to the use of remote sensing devices and computer-generated imageries, pattern recognition, influencing decision-making and design, with the system’s capacity to generate new knowledge with the overlay and combination processes of point elements. This thesis situates the Canada Geographic Information System within the context of Cybernetics and Information theories, and in turn positions it within philosopher Gilbert Simondon’s theory of concretization of technical objects and of his key points theory, linking technical objects to the territory, considered as subjective and aesthetic productions.
244

The Impact of Voluntary Front-of-Pack Nutrition-Label Introduction on Purchase Behavior / Three Studies Analyzing Supermarket Scanner Data

Elshiewy, Ossama 27 January 2015 (has links)
No description available.
245

Field observations of wave induced coastal cliff erosion, Cornwall, UK

Earlie, Claire Siobhan January 2015 (has links)
Coastal cliff erosion is a widespread problem that threatens property and infrastructure along many of the world’s coastlines. The management of this risk calls for robust quantification of cliff erosion rates, which are often difficult to obtain along rocky coasts. Quantification of sea-cliff rates of retreat on annual to decadal time scales has typically been limited to rapidly eroding soft rock coastlines. Rates of erosion used for shoreline management in the UK are generally based on analysis of historic maps and aerial photographs which, in rocky coast environments, does not wholly capture the detail and timing at which the processes operate and the failures occur across the cliff face. The first stage of this study uses airborne LiDAR (Light Detection and Ranging) data at nine sites around a rocky coastline (Cornwall, UK) to gain a quantitative understanding of cliff erosion where average recession rates are relatively low (c. 0.1 m yr-1). It was found that three-dimensional volumetric changes on the cliff face and linear rates of retreat can be reliably calculated from consecutive digital elevation models (DEMs) several years apart. Rates of erosion ranged between 0.03–0.3 m yr-1. The spatial variability in recession rates was considered in terms of the relationship with the varying boundary conditions (rock mass characteristics, cliff geometries, beach morphology) and forcing parameters (wave climate and wave exposure). Recession rates were statistically correlated with significant wave height (Hs), rock mass characteristics (GSI) and the ratio between the two (GSI/Hs). Although the rates derived using airborne LiDAR are comparable to the longer term rates of retreat, the detail of erosion to the cliff-face provides additional insight into the processes occurring in slowly eroding environments, which are vital for understanding the failure of harder rock coastlines. In addition to this, the importance of the wave climate and rainfall needs further attention on a more localised scale. Monthly cliff face volume changes, at two particularly vulnerable sites (Porthleven and Godrevy, Cornwall, UK), were detected using a Terrestrial Laser Scanner (TLS). Using these volumes alongside information on beach profile, beach- cliff junction elevation changes and nearshore hydrodynamics have allowed an insight into how the cliffs respond to seasonal fluctuations in wave climate and beach morphology. Monthly variability in beach morphology between the two sites over a one-year survey period i  indicated the influence that beach slope and the elevation of the beach-cliff junction have on the frequency of inundation and the power of wave-cliff impacts. Failure mechanisms between the two sites ranged from rotational sliding of superficial material to quarrying and block removal over the entire cliff elevation, according to the extent of wave-cliff interaction. This particular survey period highlighted the sensitivity of cliff erosion to the variability in wave climate and beach morphology at two different locations in the south-west of the UK, where the vast majority (over 85% of the annual value) of cliff face erosion occurs during the winter when extreme storm waves prevail. Coastal cliff erosion from storm waves is observed worldwide but the processes are notoriously difficult to measure during extreme storm wave conditions when most erosion normally occurs, limiting our understanding of cliff processes. Over January-March 2014, during the largest Atlantic storms in at least 60 years with deep water significant wave heights of 6 – 8 m, cliff-top ground motions of a rocky cliff in the south-west of the UK (Porthleven, Cornwall) showed vertical ground displacements in excess of 50–100 μm; an order of magnitude larger than observations made previously. Repeat terrestrial laser scanner surveys, over a 2-week period encompassing the extreme storms, gave a cliff face volume loss 2 orders of magnitude larger than the long-term erosion rate. Cliff-top ground motions and erosion volumes were compared at two different locations, one a reflective beach with steeply shelving bathymetry (Porthleven, Cornwall) and the other an intermediate, low tide bar-rip beach with a wide coastal slope (Godrevy, Cornwall). Under similar wave conditions (6–8 m Hs and 15–20 s. Tp) the vertical ground motions were an order of magnitude greater at the cliffs fronted by steeply shelving bathymetry, where the breaking waves plunge right at the shoreline, with little prior dissipation, leading to large energetic runup impacting the cliff. These storm results imply that erosion of coastal cliffs exposed to extreme storm waves is highly episodic and that long-term rates of cliff erosion will depend on the frequency and severity of extreme storm wave impacts as well as the wave dissipation that occurs as a function of the nearshore bathymetry. Having recorded microseismic cliff-top motion on this scale for the first time and determined an effective method of monitoring the energetic wave impacts, this study emphasises how investigations of cliff behaviour during storms is not only obtainable, but paramount to understanding coastal evolution under extreme conditions.
246

Proposition d'outils statistiques pour améliorer, par la tomodensitométrie, les stratégies diagnostiques et thérapeutiques. Application aux douleurs abdominales aiguës : application aux douleurs abdominales aiguës / Proposal of statistical tools to improve, through computed tomography, diagnostic and therapeutic strategies : utilization in acute abdominal pain

Cenac-Millet, Ingrid 21 October 2015 (has links)
La douleur abdominale aiguë (DAA) est un problème de santé publique du fait de sa fréquence, du large éventail de pathologies causales et de son enjeu thérapeutique avec une nécessité d'opérer rapidement les patients à risque et de ne pas opérer la plupart des patients. Le retard ou l'insuffisance diagnostique d'une urgence abdominale, qu'elle soit non traumatique (en particulier en cas de strangulation, d'ischémie digestive ou de péritonite) ou traumatique, entrainera une augmentation de la morbi-mortalité. Il est donc primordial que la prise en charge diagnostique et thérapeutique repose sur de l'Evidence-Based Médecine, intégrant une expertise clinique avec les meilleurs examens para-cliniques dont les performances ont été validées par les recherches scientifiques. A ce jour, c'est la tomodensitométrie (TDM) qui s'est imposée comme l'examen complémentaire de référence en cas d'incertitude diagnostique, pour l'exploration d'une DAA. Or, les études publiées sur l'apport du scanner dans les DAA ont un certain nombre de limites : elles ne s'intéressent souvent qu'à une seule pathologie donnée et ne correspondent donc pas à la situation clinique de pathologies non identifiées, elles intègrent rarement des objectifs sur l'impact thérapeutique et présentent, pour la plupart, des faibles niveaux de preuve (niveau I ou II) sur l'échelle à 5 niveaux de la classification des études diagnostiques. Quel que soit le niveau de l'étude, des outils statistiques avancés peuvent être utilisés pour diminuer les biais d'interprétation, pour prendre en compte le degré d'incertitude diagnostique clinique, pour tenir compte de la faible prévalence de certaines pathologies urgentes et pour faciliter le transfert et la généralisation des résultats obtenus à la pratique clinique. L'objectif de cette thèse est donc de présenter des outils statistiques, en analysant les forces et limites des résultats obtenus, afin d'étayer les perspectives d'intégration dans une stratégie de prise en charge clinique. Certains de ces outils statistiques sont déjà connus et largement utilisés en imagerie, d'autres sont développés essentiellement dans les études thérapeutiques et enfin, certains sont totalement innovants.Ainsi, la première partie de cette thèse est consacrée à une mise au point sur la méthodologie de la recherche en imagerie, en exposant ses caractéristiques, ses faiblesses et ses perspectives d'évolution. La deuxième partie est constituée d'une production scientifique de 5 articles, 4 d'entre eux publiés, focalisée sur les urgences abdominales traumatiques et non traumatiques, illustrant à l'aide du développement des analyses statistiques, l'apport du scanner pour améliorer certaines stratégies diagnostiques et thérapeutiques. De cette façon, les méthodes de concordance diagnostique, de régression logistique multivariée, de construction de score diagnostique et de méta-analyse bivariée avec effets aléatoires sont explicitées. Nous avons dans le dernier article proposé une méthode d'analyse statistique innovante basée sur une notion de distance permettant d'intégrer l'incertitude diagnostique représentée par les multiples hypothèses diagnostiques face à une douleur abdominale. Cette approche permet ainsi de mesurer la valeur ajoutée de la TDM à la fois en termes d'exactitude diagnostique et de confiance diagnostique, en se rapprochant de la pratique clinique quotidienne. A l'avenir, ces outils statistiques pourraient être plus largement utilisés dans la recherche diagnostique afin d'améliorer la pertinence scientifique et l'impact clinique, à l'origine d'une meilleure prise en charge des patients, et d'une meilleure utilisation des ressources économiques. / Acute abdominal pain (AAP) is a public health problem, given its frequency, the numerous specific causes and the therapeutic impact, with patients at risk requiring urgent surgical care while most patients do not require surgery. Delayed diagnosis or misdiagnosis of an abdominal emergency, whether of non traumatic (such as bowel strangulation, or bowel ischemia, or peritonitis) or traumatic origin, will lead to increased morbidity and mortality. It is thus crucial that diagnostic and therapeutic management relies on Evidence-based Medicine, integrating clinical expertise and paraclinical tests that have been validated through scientific research. To date, computed tomography (CT) has become the reference examination to investigate AAP when diagnosis is uncertain. However, published studies evaluating the value of CT in AAP, have some limits: they often focus on a specific disease, and consequently do not meet the unsorted pathologies encountered in clinical practice, they sparsely include objectives on therapeutic impact, and most show low levels of evidence (level I or II) on the five level diagnostic studies scale. Whatever the study's level, advanced statistical methods can be used to reduce interpretation bias, take into account the clinical diagnostic uncertainty or the low prevalence of some urgent diseases, and to facilitate the transfer and generalisation of results into daily clinical practice.The aim of this work is to present statistical tools, by analysing the results' strengths and limits, in order to illustrate the perspective of integration within a clinical management strategy. Some of these statistical tools are known and largely used in imaging studies, others are essentially developed in therapeutic studies, and some are completely innovative.Thus, the first part of this thesis reports on a review of the methodological aspect of research in the field of medical imaging, showing its characteristics, its weaknesses and its development perspective.The second part is composed of 5 scientific articles - with 4 already published - and focus on traumatic and non traumatic abdominal emergencies, illustrating the value of CT in improving some diagnostic and therapeutic strategies, while detailing the statistical analyses. Hence, statistical methods for diagnostic agreement, multivariate logistic regression, diagnostic scoring-system building and bivariate random-effects meta-analysis are developed. In the last article, we propose a new statistical analysis method, based on a distance concept, allowing integrating the diagnostic uncertainty resulting from multiple diagnosis hypotheses in front of an AAP. This approach allows for investigating the added value of CT both in terms of diagnostic accuracy and diagnostic confidence, while getting close to daily clinical practice.In the future, these statistical tools could be implemented into diagnostic research in order to improve the scientific relevance and clinical impact, allowing for better patients' management, and better economic resource usage.
247

Neural mechanisms of oxytocin and serotonin interaction in non-human primates and patients with autism / L'interaction entre l'ocytocine et la dopamine chez l'homme : implications pour la neurobiologie de la personnalité sociale

Lefevre, Arthur 13 December 2016 (has links)
La neurohormone ocytocine (OT) est de plus en plus étudiée pour son potentiel thérapeutique dans les troubles du comportement social, comme l'autisme, qui sont associés à une dérégulation de plusieurs systèmes de neurotransmission, notamment l'OT et la sérotonine (5-HT). Dans ce cadre, une étape importante afin de développer des médicaments basés sur des mécanismes biologiques est de caractériser les interactions entre l'OT et les autres neurotransmetteurs. La littérature sur les rongeurs montre que la relation entre OT et 5-HT est fortement impliquée dans plusieurs aspects du comportement social. Par ailleurs, nous avons récemment montré chez le sujet sain que le fonctionnement du récepteur 5-HT 1A (5-HT1AR) est modifié suite à l'administration d'OT.neuroJ'ai donc réalisé une première expérience chez des patients autistes en utilisant le scanner TEP avec le radiotraceur [18F]MPPF (spécifique du 5-HT1AR). Aucune différence n'est apparue, à l'état basal, entre 18 patients autistes et 24 sujets contrôles. Par ailleurs, l'OT n'a pas modifié le système 5-HT1AR. Enfin, alors qu'une corrélation entre la densité de 5-HT1AR et le volume de matière grise du striatum a été observé dans le groupe contrôle, cette relation était absente dans le groupe de patients. Ces résultats suggèrent une altération subtile du 5-HT1AR, ne pouvant être détectée qu'au niveau fonctionnel.Parce que le scanner TEP ne permet pas de dire si les changements observés sont dus à une libération de sérotonine ou à une modification directe du récepteur, j'ai réalisé une deuxième expérience chez 3 macaques rhésus, avec le [18F]MPPF et le [11C]DASB (marquant le transporteur de la 5-HT). Par rapport au placebo, l'OT injectée dans le ventricule latéral a significativement augmenté la liaison du [18F]MPPF dans l'amygdale et l'insula tandis que la liaison du [11C]DASB diminuait dans ces mêmes régions. Ainsi, nous pouvons dire que l'OT a provoqué la libération de 5-HT ainsi qu'une modification du 5-HT1AR dans ces régions importantes pour les comportements socio-émotionnels. Une étude par autoradiographie a confirmé cette interprétation.Ces expériences montrent qu'il existe une action régulatrice de l'OT sur la 5-HT chez le primate, mais que ce mécanisme est dérégulé chez les patients avec autisme. Cela ouvre donc la voie à l'investigation de traitements combinés exerçant un effet sur ces deux neurotransmetteurs / The neurohormone oxytocin (OT) is increasingly studied for its therapeutic potential in social disorders, like autism, which are associated with the deregulation of several neurotransmission systems, including OT and serotonin (5-HT). Hence investigating OT’s interactions with other neurotransmitters is a relevant step towards mechanism-based treatments. Studies in rodents demonstrated that the interaction between OT and 5-HT, is critical for several aspects of social behaviour. Moreover, using PET-scan in humans we have recently found that 5-HT 1A receptor (5-HT1AR) function is modified after intra-nasal oxytocin intake. Thus I performed a first experiment in which intra-nasal OT was administered to patients with autism undergoing a [18F]MPPF (a 5-HT1AR radiotracer) PET scanner, in order to study their basal serotonergic system and to look if the oxytocin modulates the 5-HT1AR system. I found no differences of baseline 5-HT1AR concentration between 18 autistic subjects and 24 controls. Critically, in patients, OT did not induce changes on the 5-HT1AR system. Moreover, in controls, there was a correlation between 5-HT1AR and grey matter volume in the striatum, that was not observed in patients. These results suggest a subtle disruption of patients’ serotonergic system, that can only be seen at the functional level. Because PET scan does not tell us if the observed modification is due to a change in 5-HT1AR or 5-HT concentration, I performed a second PET scan experiment on 3 macaque monkeys, using [18F]MPPF and [11C]DASB, that marks the serotonin transporter. Compared to placebo, OT injections in the lateral ventricle significantly reduced [11C]DASB binding potential in right amygdala, insula and hippocampus whereas [18F]MPPF binding potential increased in right amygdala and insula. Thus we reproduced results obtained in healthy humans and extended it by suggesting that OT provokes the release of 5-HT in key limbic regions involved in socio-emotional processing. These results were confirmed with autoradiography.Taken together, these experiments indicate that OT modulates 5-HT release in primates, but this mechanism is disrupted in patients with autism. This opens ways to investigate combined OT/5-HT treatments, especially since FDA approved drugs targeting the two systems are already available for use in patients with autism
248

Lutning och Buktningskontroll av horisontell yta med geodetiska mätinstrument

Ekelund, Hugo, Gustavar, Joakim January 2017 (has links)
Utförande av kontroller av olika objekt i byggskedet är av stor betydelse för att undvika onödiga kostnader och förseningar. Betonggolv är en typ av objekt som har toleranskrav avseende lutning och buktighet. I Sverige gäller det svenska referensverket AMA-Hus, där anges toleranser för lutning och buktighet. Buktighet kontrolleras för två olika diametrar på 0,25 m respektive 2 m, i den här studien benämnda som lokal och global buktighet.Avsikten med studien var att identifiera det optimala tillvägagånssättet att kontrollera lutning och buktighet av en horisontell yta samt infallsvinkelns påverkan vid reflektorlösa mätningar. Rutnätsskanning med olika punktavstånd utförd med multistation och laserskanning från multistation och laserskanner har använts för att samla in data. Före mätning placerades konstgjorda upphöjda buktningar ut på golvet. Data från mätningarna interpolerades i Surfer-mjukvara, där kartor med höjdkurvor skapades. Interpolationsmetoden som användes var Kriging. Även ett program för objektiv kontroll av buktighet utvecklades i samarbete med en civilingenjör i datateknik.Vid analys konstaterades det att rutnätsskanningarna med punktavstånden över 12,5 cm ej anses lämpliga för kontroll av buktighet. Rutnätsskanningen med punktavstånd på 12,5 cm eller tätare kan inte heller anses optimal för kontroll av buktighet då tidsåtgången blir för omfattande. Laserskanning med multistationen är det tillvägagångsätt som utifrån resultatet i denna studie, baserat på kontrollbarhet av buktighet och lutning, ger tydligast resultat i förhållande till tidsåtgång.Högre infallsvinkel från mätningar längre bort från instrumentet visade ingen systematisk inverkan på mätningarna i denna studie. Den ökade punkttätheten som påvisats nära instrumentet orsakade något som tolkats som brus i punktmolnet och förhöjd tidsåtgång för utförande av mätningar. / Performing controls of different types of objects in the construction phase of buildings are of great importance to avoid unnecessary costs and delays. Concrete floors are one type of object that has defined tolerances regarding levelness and flatness. In Sweden, the tolerance for levelness and flatness can be found in the national guideline AMA-Hus. Flatness is controlled within two different diameters of 0.25 m and 2 m respectively, in this study referred to as local and global flatness.The aim of this study was to identify the optimal method to control levelness and flatness of a horizontal surface and to determine the effect from the angle of incidence using reflectorless measurements. Grid scanning with different point density performed with a multi station and laser scans from multi station and laser scanner were used to collect the data. Before measurements artificial elevated curvatures where placed on the concrete floor. Data from the measurements where interpolated in Surfer software, and height maps were created. The interpolation method used was Kriging. Software containing an algorithm for objective flatness detection was developed in cooperation with a civil engineer in computer science.Analysis of the grid scanning data revealed that point density over 12.5 cm is not sufficient to detect significant elevation differences when controlling flatness. Grid scanning at 12.5 cm or thicker also cannot be deemed optimal since the time required to perform the measurements are disproportionately long. Laser scanning using the multi station proved, in the conditions of this study, to be the optimal method for levelness and flatness control in respect to time consumption.Steeper angle of incidence from measurements further from the instrument showed no systematical deviations of the measurements in this study. However, the increased point density found close to the instrument caused something that could be considered as noise in the point cloud as well as increased time consumption.
249

3D skener pro výukové účely / 3D scanner for educational purposes

Romanovský, Jiří January 2017 (has links)
This diploma thesis deals with the design of a 3D optical scanner using the structured light projection method. The aim of this thesis is to demonstrate the principles and processes of 3D scanning by using the DLP LightCrafter projector and the ImagingSource camera. The individual stages of the measurement process will be implemented to the Matlab software environment to describe the various principles and methods which can be used for digitizing the objects.
250

Korekce barev 3D scanneru a 3D tiskárny / Color Correction for 3D scanner and 3D printer

Kratochvíla, Michael January 2019 (has links)
This thesis deals with color correction of a chain that starts with the 3D Artec MHT scanner, and ends with the 3D printers (CJP – Color Jet Printing technology). In principle, it is necessary to control the color interpretation of the entire chain from the scanning of real models to the 3D print model. With color properties and their color shade, including color textures. The principle of model surface scanning using a 3D scanner is in the same principle as photo camera which scans using a conventional CMOS chip. For this reason, color palettes were scanned using the photo camera and the resulting digital data were analyzed by the Darktable software. This analysis consisted of comparing the scanned color shades of the surface with the spectrofotometer measured data. The main goal of this method was to achieve color precision in the digital data during their acquirement, adjustment and interpretation. Then the same principle was applied to the data acquired by the 3D scanner to create an ICC profile of the 3D scanner. Because the 3D printer (CJP – Color Jet Printing) uses the same principle as the 2D printer, the 2D printing device calibration principle was used again to calibrate it. There have been defined procedures that adjust the color shade to the spectrophotometrically correct shades of the resulting print on a 3D printer. Color swatches were also printed for print quality verification. It has been found that with photo camera, which was used for objective measurement in the L*a*b* coordinates of independent space, any color setting and their adjustment is very sensitive to even small imprecisions. It has been found that it is not easy to obtain accurate colors within the Detla E

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