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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.
181

The use of ALICE, a visual environment for teaching and learning object-oriented programming

Dwarika, Jeraline 23 April 2014 (has links)
University students learning object-oriented programming (OOP) encounter many complexities. This study undertook empirical research aimed at analysing learners’ interactions with the Alice visual programming environment, which seeks to engage and motivate learners to grasp concepts of OOP, whilst creating animated movies and video games. A mixed-methods approach was employed, using questionnaire surveys and interviews to investigate learners’ experiences with Alice and their understanding of OOP. Findings indicated that learners lacked problem-solving abilities; were unable to grasp programming concepts on an abstract level and spent insufficient time practicing programming exercises. Alice proved to be an effective tool in helping to address these challenges and in improving learners’ grasp of OOP. Learners found Alice to have good usability. Furthermore, test and exam results revealed a statistically significant difference between performances of learners who had been taught Alice in comparison to similar learners who were not exposed to the Alice intervention. / Computing / Information Systems / M. Sc. (Information systems)
182

Virtual reconstruction of stratigraphy and past landscapes in the West Coast Fossil Park region

Erasmus, Lelandi 04 1900 (has links)
Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2005. / The West Coast Fossil Park near Langebaanweg in the Western Cape, South Africa, is known for its abundance of marine, freshwater and terrestrial fossils of Mio-Pliocene age. The fossil bearing deposits reflect the complex and varied depositional environments, which were influenced by the change in course of the Berg River and regressions and transgressions of sealevel. The fossil deposits at this site are world-renowned for their species richness and uniqueness and there was a need to gain an in-depth understanding of the events that gave rise to this situation. To understand these complexities, it was necessary to construct a composite model of the pre-history of the West Coast Fossil Park, incorporating topological, geological and palaeontological data. GIS provided the ideal platform to integrate data from such varied sources, using spatial correlation to interpret commonalities. Subsequently, a spatially explicit database of the present-day study area, from Dwarskersbos in the north to just north of Yzerfontein in the south, was constructed. The oldest geological formation, the basement layer, as well as three successive formations was reconstructed on a regional scale using borehole data. Interpolation of point data to regional surfaces was a dual process incorporating expert opinion and purpose-built tools within ESRI’s ArcInfo and ArcMap 8.3. A similar reconstruction at a finer scale was done for the West Coast Fossil Park area using kriging as an interpolation method. These reconstructed geological layers can be used to predict the depth and location of fossil-bearing deposits. There is scope for further study and analysis to compare the accuracy of alternative interpolation methods, and combining it with field-based validation of modelled outputs.
183

Análise do processo de retificação interna aplicado à fabricação de bicos injetores diesel / Internal surface grinding process analysis in diesel nozzles

Bilha, Vitor Meira 14 December 2015 (has links)
A utilização mais eficiente dos recursos naturais tem levado a indústria a aumentar a eficiência dos produtos manufaturados. Veículos de transporte Diesel estão incluídos neste cenário. Nos motores Diesel, um componente importante do sistema de injeção é o bico injetor. Uma legislação recente no Brasil introduziu limites de emissões EURO5. Estes novos parâmetros tiveram impacto no projeto do bico injetor com tolerâncias sendo reduzidas, em especial na área da sede do corpo do bico injetor, alterando o parâmetro funcional de pressão de abertura do produto. Neste cenário, o impacto desta superfície cônica retificada sobre a pressão de abertura é grande, bem como, sobre o desempenho do motor Diesel. Este estudo tem como objetivo analisar o defeito de topografia superficial típico e recorrente no processo de retificação interna cônica da sede do corpo dos bicos injetores. Um experimento planejado foi realizado de acordo com método Taguchi e determinou-se a relação sinal-ruído para dois parâmetros de topografia 2D. A superfície da sede também foi analisada utilizando análise topográfica 3D. Os resultados deste estudo incluem a indicação de possíveis causas do defeito recorrente, caracterização dos principais elementos do processo de retificação, caracterização da superfície retificada e otimização dos parâmetros do processo de retificação. / Industries of manufactured products have increased their efficiency optimizing the natural resources usage and Diesel commercial vehicles are included in this scenario. For Diesel engines, one of the most important components of the injection system is the nozzle injector. In Brazil, EURO5 legislation was recently introduced, bringing new emission limits for Diesel engines. Because of this, the nozzle injector design has changed and some manufacturing tolerances were reduced, in special the body seat geometry. This also changed the nozzle opening pressure. In this new process, the body seat grinded conical surface impacts on this functional parameter and consequently the Diesel engine performance. This study has as target to analyze a recurrent defect in the internal conic grinding process of the nozzle body seat. A trial was performed in this process according to Taguchi method and signal / noise ratio for 2D topographic parameters were defined. The body seat surface was also analyzed using 3D topographic analysis. The results of this study include the possible cause of the recurrent failure, characterization of the ground surface, process main elements integrity assessment and optimization of the grinding process parameters.
184

The use of ALICE, a visual environment for teaching and learning object-oriented programming

Dwarika, Jeraline 23 April 2014 (has links)
University students learning object-oriented programming (OOP) encounter many complexities. This study undertook empirical research aimed at analysing learners’ interactions with the Alice visual programming environment, which seeks to engage and motivate learners to grasp concepts of OOP, whilst creating animated movies and video games. A mixed-methods approach was employed, using questionnaire surveys and interviews to investigate learners’ experiences with Alice and their understanding of OOP. Findings indicated that learners lacked problem-solving abilities; were unable to grasp programming concepts on an abstract level and spent insufficient time practicing programming exercises. Alice proved to be an effective tool in helping to address these challenges and in improving learners’ grasp of OOP. Learners found Alice to have good usability. Furthermore, test and exam results revealed a statistically significant difference between performances of learners who had been taught Alice in comparison to similar learners who were not exposed to the Alice intervention. / Computing / Information Systems / M. Sc. (Information systems)
185

Etude biomécanique de la mimique faciale / Biomechanical study of facial mimics movements

Dakpé, Stéphanie 19 May 2015 (has links)
Ce travail de thèse, inclus dans un projet structurant plus vaste, projet SIMOVI (SImulation des MOuvements du VIsage), s’attache à étudier spécifiquement la mimique faciale en corrélant les déplacements visibles du revêtement cutané et les mouvements musculaires internes à travers le développement de plusieurs méthodologies. L’ensemble de la mimique faciale ne pouvant être étudié, étant donné la multitude d’expressions, les mouvements pertinents à étudier dans nos travaux ont été identifiés. Ces mouvements ont été caractérisés chez 23 sujets jeunes dans une analyse descriptive qualitative et clinique, basée sur une méthodologie s’appuyant sur l’analyse d’enregistrements vidéoscopiques, et le développement d’un codage issu du FACS (Facial Action Coding System). Une cohorte de référence a ainsi été constituée. Après avoir validé notre méthodologie pour la caractérisation externe de la mimique, l’analyse des muscles peauciers par l’IRM a été réalisée sur 10 hémifaces parmi les sujets sains issus de la cohorte. Cette caractérisation a fait appel, à partir d’une anatomie in vivo, à une modélisation de certains muscles peauciers (zygomaticus major en particulier) afin d’extraire des paramètres morphologiques, de réaliser une analyse plus fine de la morphologie musculaire en 3 dimensions, et d’apporter une meilleure compréhension du comportement cinématique du muscle dans différentes positions. Par son intégration dans un questionnement plus vaste :- comment caractériser objectivement la mimique faciale ? - quels sont les indicateurs qualitatifs et quantitatifs de la mimique que nous pouvons recueillir, et comment réaliser ce recueil ? - comment utiliser les développements technologiques dans les applications cliniques ? Ce travail constitue une étape préliminaire à d’autres travaux. Il pourra fournir des données de référence à des fins de modélisation, de simulation de la mimique faciale, ou de développements d’outil de mesures pour le suivi et l’évaluation des déficits de la mimique faciale. / The aim of this research is to study facials mimics movements and to correlate externat soft tissue (i.e., cutaneous) movement during facial mimics with internal (i.e., facial mimic muscle) movement. The entire facial mimicry couldn't be studied, that's why relevant movements had been selected. Those movements were characterised by a clinically qualitative analysis in 23 young healthy volunteers. The analysis was performed with video recordings including scaling derived from the FACS (Facial Action Coding System). After the validation of external characterisation by this method, internal characterisation of the mimic facial muscle was carried out in 10 volunteers. A modelization of selected facial mimic muscle as Zygomaticus Major was achieved. With this work, morphological parameters could be extracted, 3D morphometric data were analysed to provide a better understanding of cinematic behaviour of muscle in different positions.This research is included in the Simovi Project, which aims to determine to what extent a facial mimic can be evaluated objectively, to select the qualitative and quantitative indicators for evaluation of mimic facial disorders, and to transfer our technological developments in clinical field. This research is a first step and provides data for simulation or developments of measurement tools in evaluation and follow-up of mimic facial disorders.
186

A high resolution 3D and color image acquisition system for long and shallow impressions in crime scenes

Egoda Gamage, Ruwan Janapriya January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In crime scene investigations it is necessary to capture images of impression evidence such as tire track or shoe impressions. Currently, such evidence is captured by taking two-dimensional (2D) color photographs or making a physical cast of the impression in order to capture the three-dimensional (3D) structure of the information. This project aims to build a digitizing device that scans the impression evidence and generates (i) a high resolution three-dimensional (3D) surface image, and (ii) a co-registered two-dimensional (2D) color image. The method is based on active structured lighting methods in order to extract 3D shape information of a surface. A prototype device was built that uses an assembly of two line laser lights and a high-definition video camera that is moved at a precisely controlled and constant speed along a mechanical actuator rail in order to scan the evidence. A prototype software was also developed which implements the image processing, calibration, and surface depth calculations. The methods developed in this project for extracting the digitized 3D surface shape and 2D color images include (i) a self-contained calibration method that eliminates the need for pre-calibration of the device; (ii) the use of two colored line laser lights projected from two different angles to eliminate problems due to occlusions; and (iii) the extraction of high resolution color image of the impression evidence with minimal distortion.The system results in sub-millimeter accuracy in the depth image and a high resolution color image that is registered with the depth image. The system is particularly suitable for high quality images of long tire track impressions without the need for stitching multiple images.

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