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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.
21

Creating realistic hair in Autodesk Maya

Ludwigsson, Jonas January 2013 (has links)
This thesis work focuses on how to create realistic looking hair using only the vanilla version of Autodesk Maya. It describes two approaches, the widely used polygon-stripe based technique and the Maya built-in nHair. It also evaluates these two approaches in terms of ease of implementation, production speed and quality of final results. The conclusion is that nHair has the potential to produce realistic looking hair but contains various bugs and is not optimized at the current stage, while the polygon-stripe based approach is robust and flexible but the realism of rendering results is heavily dependent upon the skill level of artists.
22

Physical, mechanical and surface properties of dental resin-composites

Alrahlah, Ali Awad January 2013 (has links)
Since resin composites were first presented to dentistry more than half a century ago, the composition of resin composites has developed significantly. One major change was that the reinforcing filler particles were reduced in size to generate materials of a given filler content that display better physical and mechanical properties. Resin composites may absorb water and chemicals from the surrounding environment but at the same time, composites may release constituents to their surroundings. The physical/mechanical properties of a restorative material provide an indication of how the material will function under stress in the oral environment. The aims of this research were to examine the effects of water at 37°C on the physical and mechanical properties, and the effect of food-simulating solvents of a variety of experimental and contemporary resin composites, on the surface properties. Eight representative resin composites were selected (Exp. VT, BL, NCB, TEC, GSO, XB, VDF and CXD). Due to the recent development of bulk fill materials on the market during the course of this research, the post-cure depth of cure of new bulk fill materials was also investigated. Five representative resin composites were selected: TBF, XB, FBF, VBF and SF. Water sorption and solubility were investigated at 37°C for 150 days. Sorption and solubility are affected by the degree of hydrophilicity of the resin matrix. The bulk fill materials examined showed the lowest water sorption and solubility. Laser scan micrometer (LSM) was used to investigate hygroscopic expansion. The extent of the hygroscopic expansion positively correlated with the amount of water sorption. The effect of water on fracture toughness was also examined. A self-adhesive hydrophilic resin matrix decreased in fracture toughness after 7 days of storage at 37°C. By contrast, the least water absorbed bulk fill material increased in fracture toughness over time. The effect of food-simulating solvents (distilled water, 75% ethanol/water and MEK) on surface micro-hardness, colour stability and gloss retention were investigated. The MEK solvent resulted in the lowest micro-hardness and the greatest colour change (ΔE) for most of the examined composites, while the 75% ethanol/water solution caused the greatest loss in gloss for most of the examined composites. A highly filled nano-composite showed the best result over time, regardless of the condition of storage. Surface micro-hardness profiles were used as an indirect method to assess the depth of cure of bulk fill resin composites. The examined bulk fill resin composites can be cured to an acceptable depth (4 mm).
23

An Investigation of Measuring Energy and Power During Walking on Slopes Using Foot Mounted Inertial Magnetic sensors

Oagaz, Hawkar Ali 01 August 2017 (has links)
No description available.
24

A Proof of Concept for Homomorphically Evaluating an Encrypted Assembly Language

Rakas, Dragan 10 1900 (has links)
<p>Fully homomorphic encryption allows computations to be made on encrypted data without decryption, while preserving data integrity. This feature is desirable in a variety of applications such as banking, search engine and database querying, and some cloud computing services. Despite not knowing the plaintext content of the data, a remote server performing the computation would still be aware of the functions being applied to the data. To address the issue, this thesis proposes a method of encrypting circuits and executing encrypted instructions, by combining fully homomorphic encryption and digital logic theory. We use the classic RISC Archtecture as a foundation of our work, and the result of our algorithm is essentially an encrypted programming language, where a remote server is capable of executing program code that was written and encrypted by a local client.</p> / Master of Science (MS)
25

Precision Neutrino Oscillations: Important Considerations for Experiments

Pestes, Rebekah Faith 26 May 2021 (has links)
Currently, we are in an era of neutrino physics in which neutrino oscillation experiments are focusing on doing precision measurements. In this dissertation, we investigate what is important to consider when doing these precise experiments, especially in light of significant unresolved anomalies. We look at four general categories of considerations: systematic uncertainties, fundamental assumptions, parameterization-dependence of interpretations, and Beyond the Standard Model (BSM) scenarios. By performing a simulation using GLoBES, we find that uncertainties in the fine structure of the reactor neutrino spectrum could be vitally important to JUNO, a reactor neutrino experiment being built in China, so a reference spectrum with comparable energy resolution to JUNO is needed in order to alleviate this uncertainty. In addition, we determine that with their fix of the fine structure problem, JUNO can test the existence of a quantum interference term in the oscillation probability. We also reason that the CP-violating phase is very parameterization dependent, and the Jarlskog invariant is better for talking about amounts of CP violation in neutrino oscillations. Finally, we discover that CP-violating neutrino Non-Standard Interactions (NSIs) could already be affecting the outcomes of T2K and NOνA, two accelerator neutrino experiments, and may be why there is a tension in these two data sets. / Doctor of Philosophy / Neutrinos are very weakly interacting, fundamental particles that are extremely plentiful in the universe. There are three known types (or flavors) of neutrinos, and the fact that they change flavors (or oscillate) informs us that their mass is not zero, but no experiments have been able to put a lower bound on the smallest neutrino mass. Now that experiments measuring neutrino oscillations have become more precise and some significant anomalies remain unresolved, there are considerations that have become important to investigate. In this paper, we look at four of these considerations: • Uncertainties in the finer shapes in the energy spectrum of neutrinos coming from a nuclear reactor (Chapter 2): We find that these uncertainties could destroy the ability of the Jiangmen Underground Neutrino Observatory (JUNO) to meet one of its major goals, unless they measured the spectrum at a spot close to the reactor with a really good energy resolution (comparable to that of JUNO). • An assumption about quantum mechanics being the foundation of particles and their interactions (Chapter 3): We determine that by heeding our warning in Chapter 2, JUNO will be able to test the existence of the term in the oscillation probability arising out of quantum interference. • How the neutrino oscillation parameter known as the CP-violating phase is dependent on the parameterization scheme used for the matrix describing how the flavors mix to make neutrino oscillation possible (Chapter 4): We find that the parameterization dependence is drastic, and if we want to discuss how much CP violation (i.e. a measure of how neutrinos behave differently from their anti-matter counterparts) exists in neutrino oscillations, we should talk about a quantity called the Jarlskog invariant. • The possibility of interactions existing between neutrinos and other particles that are not part of the Standard Model of Particle Physics, i.e. neutrino Non-Standard Interactions (NSIs) (Chapter 5): We discover that NSIs that are CP-violating can actually explain a current discrepancy between two neutrino oscillation experiments: Tokai to Kamioka Nuclear Decay Experiment (T2K) and NuMI Off-axis ν e Appearance (NOνA).
26

Slicing of extended finite state machines

Atchuta, Kaushik January 1900 (has links)
Master of Science / Department of Computing and Information Sciences / Torben Amtoft / An EFSM (Extended Finite State Machine) is a tuple (S, T, E, V) where S is a finite set of states, T is a finite set of transitions, E is a finite set of events, and V is a finite set of variables. Every transition t in T has a source state and a target state, both in S. There is a need to develop a GUI which aids in building such machines and simulating them so that a slicing algorithm can be implemented on such graphs. This was the main idea of Dr. Torben Amtoft, who has actually written the slicing algorithm and wanted this to be implemented in code. The project aims at implementing a GUI which is effective to simulate and build the graph with minimum user effort. Poor design often fails to attract users. So, the initial effort is to build a simple and effective GUI which serves the purpose of taking input from the user, building graphs and simulating it. The scope of this project is to build and implement an interface so that the users can do the following in an effective way:  Input a specification of an EFSM  Store and later retrieve EFSMs  Displaying an EFSM in a graphical form  Simulating the EFSM  Modify an EFSM  Implement the slicing algorithm All the above mentioned features must be integrated into the GUI and it should only fail if the input specification is wrong.
27

The Oxford Vehicle Model : a tool for modeling and simulating the powertrains of electric and hybrid electric vehicles

Doucette, Reed January 2013 (has links)
This dissertation addresses the challenges of scoping and sizing components and modeling the tank to wheel energy flows in new and rapidly evolving classes of automotive vehicles. It introduces a system of computer models, known as the Oxford Vehicle Model (OVEM), which provide for the novel simulation of the powertrains of electric (EV) and hybrid electric vehicles (HEV). OVEM has a three-level structure that makes a unique contribution to the field of vehicle analysis by enabling a user to proceed from performing scoping and sizing exercises through to accurately simulating the energy flows in powertrains of EVs and HEVs utilizing existing and emerging technologies based on real world data. Level 1 uses simplified models to support initial component scoping and sizing exercises in an analysis environment where uncertainty regarding component specifications is high. Level 2 builds on Level 1 by obtaining more refined component scoping and sizing estimates via the use of component models based on well-understood scientific principles that are product-independent – a crucial feature for obtaining unbiased scoping and sizing estimates. Level 3 employs a high degree of fidelity in that its models impose actual physical limits and are based on data from real technologies. This dissertation concludes with two chapters based on studies published as journal articles that used OVEM to address key issues facing the development of EVs and HEVs. The first study used OVEM to make the novel comparison between high-speed flywheels, batteries, and ultracapacitors on the bases of cost and fuel consumption while functioning as the energy storage systems in an HEV. The second study applied OVEM towards a novel examination of the CO2 emissions from plug-in HEVs (PHEVs) and compares their CO2 emissions to those from similar EVs and ICE-based vehicles.
28

Programa para estimativa do rendimento das culturas pela simulação da irrigação por balanço hídrico sequencial. / Software to estimate crop yield by simulating irrigation using sequential water balance.

Jacomazzi, Marco Antonio 18 November 2004 (has links)
A utilização de recursos computacionais para o planejamento do uso racional da água em sistemas irrigados é cada vez mais freqüente na agricultura moderna tecnificada. Devido a constante melhoria desses recursos, torna-se, essencial a atualização dos programas desenvolvidos, específicos na área de irrigação e drenagem, incorporando as recentes tecnologias desenvolvidas neste setor. O objetivo deste trabalho foi elaborar uma ferramenta computacional de acesso simplificado, que proporcionasse ao usuário, a liberdade quanto aos critérios empregados nas áreas irrigadas. O programa desenvolvido é específico para o planejamento de sistemas irrigados. Esse programa foi desenvolvido para auxiliar na tomada de decisão sobre o nível de manejo de irrigação a ser adotado; com base numa previsão de chuvas simulada a partir de uma série histórica de dados e qual a máxima produtividade esperada da cultura para um determinado momento de irrigação. Como parâmetros de entrada o aplicativo requer dados sobre os parâmetros climáticos regionais; as características da cultura irrigada; as propriedades do solo quanto à capacidade de armazenamento de água e operação do manejo de água adotado. O aplicativo permite, a partir dos dados climáticos disponíveis, estimar a evapotrasnpiração potencial utilizando-se desde o modelo de Penman, que exige maior número de variáveis até o de Thornthwaite que se baseia apenas na temperatura. Simulando-se diferentes níveis de manejo da irrigação para a região de Piracicaba, onde o déficit hídrico não é acentuado, as simulações não apresentaram diferenças significativas, entretanto, supõem-se que os contrastes poderão ser potencializados para regiões mais áridas. Essa ferramenta apresentou-se ser bastante útil para o usuário, para as diferentes regiões climáticas no país e os dados climáticos disponíveis para cada caso. / The use of computers resources for planning the rational water use in irrigated systems is even more frequent in the modern technical agriculture. Due to the constant improvements of those resources, it is essential to update the developed software’s, specifically in the irrigation and drainage area, by incorporating the most recent technologies developed in this segment. The objective of this work was to elaborate a computation easy to handle tool, which allows freedom to act in relation to the used criteria in irrigated farming. The developed software is specific for planning of irrigated systems. It was developed to help decisions taking about the irrigation management level to be adopted; based on a rainfall forecast simulated on an historically sequence and the maximum crop yield expected for a specific irrigation moment. As input data, the software will need (i) regional climatic parameters, (ii) the characteristics of irrigated crop, (iii) soil properties related to water storage capacity and (iv) the adopted water management. Based on available data, user can choose among several methods of calculate the potential evapotranspiration, from Penman, which will need more climatic data, until Thornthwaite based on temperature data only. By running the program with data from Piracicaba region, where there is not a significant water deficit along the year, no difference was shown among the different methods used, but it is to suppose that in more arid regions the contrast among them will be more significantly. The developed tool presents to be useful for the user by being flexible regarding the different climatic regions of the country and also regarding available data set for each case.
29

W.A.M, Wire Additive Manufacturing : champs des possibles et utilisation raisonnée / WAM, Wire Additive Manufacturing : field of possibilities and reasoned use

Parrot, Jérôme 05 December 2018 (has links)
Dans la Fabrication Additive (FA), les objets en trois dimensions sont créés couche par couche en joignant chaque couche à la précédente. Pour les pièces métalliques, il existe trois méthodes principales : le lit de poudre, le dépôt de poudre et le dépôt de fil. Ce dernier utilise de manière optimale le matériau contrairement aux autres procédés, ce qui le rend très intéressant industriellement. En effet, avec la poudre, le rapport entre la poudre utilisée et la poudre fondue n’est pas égal à un, en opposition à l’utilisation de fil. Afin de garantir la bonne fusion du métal, plusieurs méthodes existent déjà, notamment l’utilisation de lasers ou d’arcs électriques. Ce manuscrit présente une nouvelle approche de dépôt de fil utilisant l’énergie inductive pour les applications de fabrication additive (WIAM). Cette approche ne fait pas appel à un stockage du matériau fondu. Au lieu de cela, la pointe d’un fil métallique est fondue par un système de chauffage par induction. L’énergie inductive est également utilisée pour obtenir un gradient thermique optimal entre l’extrémité du fil et le substrat ou la couche précédente. Les travaux de thèse concernent le développement de cette approche par un modèle numérique et sa validation expérimentale. Il est montré que le système de chauffage par induction est capable de faire fondre la pointe du fil et de chauffer le substrat pour créer un dépôt approprié. La microstructure après dépôt de fabrication additive pour un matériau en acier inoxydable a été étudiée. Ces résultats ont été comparés avec la méthode WAM. On montre que le système de chauffage par induction donne une microstructure à très faible porosité et une microstructure sans changement soudain de composition. Ces résultats préliminaires indiquent que la fabrication additive par fil métallique avec induction (WIAM) est susceptible de constituer un processus approprié pour la FA, mais qu’elle doit encore être développée. / In Additive Manufacturing (AM), three dimensionalobjects are built layer by layer by joining each layer to the previous one. For metal parts, there are three main methods: powder bed, powder depositionand wire deposition. This latter makes optimal use of the material in contrast to other processes, which makes it very interesting industrially. Indeed, with powder,the ratio between powder used and powder meltedis not equal to one, in opposition of the use of wire. In order to ensure the proper melting of the metal, several methods already exist, including the use of lasers or electric arc. This manuscript presents a novel approach of wire deposition using inductive energy for additive manufacturing applications (WIAM). This approach does not make use of a storage of the molten material. Instead, the tip of a metal wire is melted by an induction heating system. Inductive energy is also used to obtain an optimal thermal gradient between the tip of the wire and the substrate or previous layer. Thesis work concerns the development of this approach by a numerical model, and its experimental validation. It shows that the induction heating system is able to melt the tip of the wire and heat the substrate to create suitable deposition. The microstructure of additive manufacturing stainless steel has been studied. These results have been compared with WAM method. It is shown that the induction heating system gives a microstructure with very low porosities and a microstructure without a sudden change of composition. These preliminary results indicate that Wire Induction Additive Manufacturing (WIAM) is likely to a suitable process for AM but it still needs to be developed.
30

Water Simulating in Computer Graphics

Wu, Liming, Li, Kai January 2007 (has links)
<p>Fluid simulating is one of the most difficult problems in computer graphics. On the other hand, water appears in our life very frequently. This thesis focuses on water simulating. We have two main methods to do this in the thesis: the first is wave based water simulating; Sine wave summing based and Fast Fourier Transform based methods are all belong to this part. The other one is physics based water simulating. We make it based on Navier-Stokes Equation and it is the most realistic animation of water. It can deal with the boundary and spray which other method cannot express. Then we put our emphasis on implement by the physics method using Navier-Stokes Equation.</p>

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