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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

Image-based 3D Model Construction

Chen, Kuan-Chen 25 July 2001 (has links)
The shape construction of three-dimensional objects has numerous applications in area that include manufacturing, virtual simulation, science, medicine, and consumer marketing. In this thesis, we consider a automatic system which captures and triangulates views of a real world 3D objects and finally registers and integrates them. There are four steps in our system, image acquisition, image processing, model construction and stereoscopic display. First step, image acquisition, we take 2D image pairs (by CCD camera movement) from different angles of the model with one CCD camera. Second step, image processing. In order to derive depth form two images captured by the CCD camera, we find registration points between two images by using image segmentation, feature extraction, image registration. Third step, 3D model construction, we divide it into three parts. First part, we generate partial depth surface by Delaunay triangle splitting , and for a selected set of viewing directions. Second part of this step, different surfaces have to be mapped into a uniform coordinate system for the given 3D object. Integration of registered surfaces defines the third part of the model construction. This finally, can lead to the generation of a complete 3D model of the given scene or of the given object. After generating a complete 3D model, we create a stereoscopic view in last step. We put on the LC-Shutter-Glasses and look through the lenses at high-resolution full color display while the lenses "shutter" on and off alternatively. The monitor displays only the left view while the right lens of the glasses shutters, and display the right view while the left lens of the glasses shutters.
2

Reconstructing the geometry of a 3-dimensional model using multiple visible surface representations

Sharma, A. January 1988 (has links)
No description available.
3

3D model kostela sv. Petra z Alkantary v Karviné / 3D model of church of st. Peter of Alkantara in Karviná

Giemza, Lukáš January 2019 (has links)
The object of this diploma thesis is surveying and creation of 3D model of the church of st. Peter of Alcantara in Karviná. In the introduction this thesis is focused on history and localization of the church. In the next part is a description of data collection, computational work and graphic processing. The final results of the thesis are the wired model, which is created in MicroStation PowerDraft V8i, and the textured 3D model made in AutoCAD 2018.
4

The Primitive Antiarch Yunnanolepis from China : A Microtomographic Study / Den primitiva antiarchen Yunnanolepis från Kina : En mikrotomografisk studie

Grahn, Jessica January 2016 (has links)
Placoderms appeared in the Silurian period and rapidly evolved and dominated the waters during the Devonian period. Among the earliest of the placoderms are yunnanolepids, a primitive form of antiarch from the Early Devonian of China and Vietnam. Very little work has so far been devoted to this family, and previous descriptions are based on conventional preparation methods. We can now take a closer look at a yunnanolepid specimen with the help of three dimensional modelling based on a synchrotron X-ray microtomographic scan series. The well preserved anterior ventrolateral plate exhibits an opening for the pectoral fin, clearly visible structures, and outer ornamentation. A first 3D image of the mysterious hollow called Chang’s apparatus has been constructed. Chang’s apparatus has only ever been seen in Yunnanolepididae, but never described in detail, and its function remains unknown. The trunk plate has captured settling sediment and in the inwash can be found tooth plates and scales of other gnathostomes. Among these are two well preserved anterior ventrolateral plates of young antiarchs. No ornamentation can be seen on the juveniles and their postbranchial lamina had not yet developed. / Placodermer (pansarhajar) är en grupp tidiga käkförsedda fiskar som dök upp under tidig silur. De spred sig snabbt under silur och dominerade världens vatten under devon, för att helt dö ut i slutet av devon. En av de allra tidigaste grupperna av placodermer är en grupp som kallas yunnanolepider, de var en primitiv form av antiarcher (armpansarhajar) från tidig devon i Kina och Vietnam. Man vet väldigt lite om denna grupp, och alla tidigare beskrivningar har baserats på konventionella prepareringsmetoder där man mekaniskt avlägsnat sediment som omgav fossilet. Här har ett fossil beskrivits med hjälp av röntgenbaserad mikrotomografi som sedan modellerats digitalt. Modellen visar en välbevarad bröstplåt, del av skuldergördelen, från yunnanolepiden. Denna visar en öppning med fäste för bröstfenan, interna strukturer och yttre ornamentering. Man kan här få en första syn på en intern hålighet som kallas Chang’s apparatus som aldrig tidigare har beskrivits i detalj. I sedimentet som samlats i bröstplåten kan man även se delar av andra organismer, såsom en tandplatta och fjäll. Bland dessa bitar finns två välbevarade bröstplåtar från juvenila antiarcher.
5

A Three-Dimensional Numerical Study Of The Impacts On The Water-Exchange In Dapeng Bay Due To Inlet

Chang, Chang-Ying 01 August 2011 (has links)
Dapeng Bay is located in the southwest coast of Taiwan. It is a cystic shaped shallow lagoon, which has only one entry for exchanging lagoon water with the coastal current. The water quality is depending on the refreshing rate and the mixing level in the lagoon. In order to understand the circulation pattern monthly measurements using an ADP are carried out. Three water quality monitoring stations are constructed for regular online observation of the water quality in the lagoon. The flows are on the west-northwest direction during the flood and toward the west during ebb. Strong currents are observed in the tidal inlet channel. The general circulation patterns are mainly dominated by tide though wind effects can observed from the measurements. This study established a three-dimensional hydrodynamic modeling system using the FVCOM model developed at the U.S. Marine Ecosystem Dynamics Modeling Laboratory for the simulation of Dapeng Bay currents. The study includes the comparison of the recent circulation and the flow fields after broaden of the inlet navigation channel. This will change not only the shape but also dredge the channel deeper. These variations may differ the circulation patterns and the exchange quantities as well. The model results are first compared with the observations for the present situation as calibration. The simulation results for the studies of the changing of the inlet channel will be discussed.
6

Characterization of polymeric microspheres used in drug delivery via electron microscopy

Gomez Monico, Jose Carlos A. 29 August 2018 (has links)
Drugs can be made up of nucleic acids, sugars, small organic and inorganic compounds, peptides, and large macromolecules. Drug therapy can be optimized by controlled delivery systems that release an appropriate dose to the site of action, extend the duration of delivery, reduce administration sessions, and can target a precise site of activity. An advanced method of controlled drug delivery is through injectable polymeric biomaterial microparticles that entrap drugs within their matrix for slow release (1-6 months). Surface morphology of polymer microparticles is known to affect drug release; however, it is often reported in qualitative terms only. In this thesis, a mastery over the controlled fabrication of biodegradable poly (ε-caprolactone) (PCL) microspheres is shown, as well as their characterization using different imaging conditions/techniques of the scanning electron microscope (SEM). Retinoic acid (RA), a morphogenic molecule, is encapsulated to create RA/PCL microspheres that are used to successfully deliver drug to human induced pluripotent stem cell aggregates. Furthermore, this works reports the creation of variable surface morphology PCL microspheres and their characterization via size analysis and stereo-microscopy. A rough morphology candidate is identified and selected for 3D SEM surface model reconstruction via a computer vision technique. Surface studies via SEM have a lot of potential to advance the development of these particles. The 3D model first reported here serves as foundation for quantitative surface morphology measurements. / Graduate
7

3D model vybraného objektu / 3D model of selected object

Majerčíková, Radka January 2015 (has links)
The subject of the thesis is to create a 3D model and technical report of Letohrádek Mitrovských in Brno. I started with the history, location and description of this object. Other part of my work is focused on making of 3D model. I have made two different models in two different programs. The main spatial model has been made in program AutoCAD and additional model in program 123DCatch. Thesis will be provided for usage in the future for the administrator of object Letohrádek Mitrovských in Brno.
8

Zaměření a vyhotovení technické dokumentace objektu kostela / Surveying and elaboration of the technical documentation of the Church Building

Ferencová, Anna Unknown Date (has links)
The subject of the diploma thesis is a elaboration technical documentation of St.Peter’s and St. Paul’s church in Banske. The first part of the documentation includes the basic overview and study background description. Further on, the subject site description is developed along with detailed description of each step related to the surveying, processing, assessment and interpretation of the collected data. Final set of drawings includes the Site plan of surrounding lots, top views, cross and longitudinal sections and elevations.
9

Samlingsmodell i 3D av damm I vid Ryllshyttemagasinet från 2007–2022 : Modell i OpenRoads Designer

Flemström, Christoffer January 2024 (has links)
Detta examensarbete bygger upp en 3D modell av damm I vid Ryllshyttemagasinet i Garpenberg, i programmet OpenRoads designer. Modellen består av inmätningar av undergrunden samt dammens delar från 2007 till 2022. Den inmätta modellen är ofullständig och har kompletterats via korridormodellering i programmet, kompletteringarna har utgått från relationsritningar från varje år, utföranderapporter, flygscanningar, samt via sektioner från damm A och I2. De inmätta och kompletterade ytorna motsvarar väl relationsritningarna och ger en god bild över dammens konstruktion längs hela damm I sträckning. Arbetet kommer ligga till grund för en 3D modell över hela Ryllshyttemagasinet och dess omkringliggande magasin och dammar som sträcker sig ända tillbaka till 60-talet. Den kompletta modellen kommer användas i beräkningssyften för att utvärdera stabiliteten när magasinets konstruktion ändras från en uppströmsdamm till en centrumlinjesdamm.
10

Analyse statistique de la diversité en anthropometrie tridimensionnelle / Statistical analysis of diversity in three-dimensional anthropometry

Kollia, Aikaterini 13 January 2016 (has links)
L’anthropométrie est le domaine scientifique qui étudie les dimensions du corps humain. La complexité de la morphologie du corps nécessite une analyse 3D, aujourd’hui permise par les progrès des scanners 3D. L’objectif de cette étude est de comparer les populations et utiliser les résultats pour mieux adapter les produits sportifs à la morphologie des utilisateurs. Des campagnes de mensuration 3D ont été réalisées et des algorithmes de traitement automatique ont été créés pour analyser les nuages de points des sujets scannés. Basés sur les méthodes d’images et de géométrie, ces algorithmes repèrent des points anatomiques, calculent des mesures 1D, alignent les sujets scannés et créent des modèles anthropométriques 3D représentatifs des populations. Pour analyser les caractéristiques anthropométriques, des statistiques de premier ordre et factorielles ont été adaptées pour être utilisées dans l’espace 3D. Les méthodes ont été appliquées à trois parties : le pied, la tête et la poitrine. Les différences morphologiques entre les populations, mais également au sein d’une population donnée, ont été révélées. Par exemple, la différence à chaque point de la tête entre des têtes a été calculée. Les statistiques en trois dimensions ont aussi permis de mettre en évidence l’asymétrie de la tête. La méthode de création de modèles anthropométriques est plus adaptée à nos applications que les méthodes dans la littérature. L’analyse en trois dimensions permet d’obtenir des résultats qui ne sont pas visibles par les analyses 1D. Les connaissances acquises par cette étude sont utilisées pour la conception de différents produits vendus dans les magasins DECATHLON à travers le monde. / Anthropometry is the scientific field that studies human body dimensions (from the greek άνθρωπος (human) + μέτρον (measure)). Anthropometrical analysis is based actually on 1D measurements (head circumference, length, etc). However, the body’s morphological complexity requires 3D analysis. This is possible due to recent progress of 3D scanners. The objective of this study is to compare population’s anthropometry and use results to adapt sporting goods to user’s morphology. For this purpose, 3D worldwide measurement campaigns were realized and automated treatment algorithms were created in order to analyze the subjects’ point cloud. Based on image processing methods and on shape geometry, these algorithms detect anatomical landmarks, calculate 1D measurements, align subjects and create representative anthropometrical 3D models. In order to analyze morphological characteristics, different statistical methods including components’ analysis, were adapted for use in 3D space. The methods were applied in three body parts: the foot, the head and the bust. The morphological differences between and inside the populations were studied. For example, the difference in each point of the head, between Chinese and European head, was calculated. The statistics in three dimensions, permitted also to show the asymmetry of the head. The method to create anthropometrical models is more adapted to our applications than the methods used in the literature. The analysis in three dimensions, can give results that they are not visible from 1D analyses. The knowledge of this thesis is used for the conception of different products that they are sold in DECATHLON stores around the world.

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