Orientadores: Roberto Antonio Clemente, Munemasa Machida / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-19T20:53:40Z (GMT). No. of bitstreams: 1 Duarte_ViniciusNjaim_M.pdf: 5509797 bytes, checksum: 163bd7750aa0326f7bf0d0b521dc88f0 (MD5) Previous issue date: 2012 / Resumo: Entre os diferentes métodos alternativos à indução, para sustentação e/ou geração de corrente em plasmas confinados magneticamente, com o objetivo de se obter o funcionamento contínuo de um possível reator de fusão, foi estudado aquele associado a campos magnéticos viajantes produzidos por bobinas helicoidais alimentadas por correntes de radiofrequência defasadas (double helix current drive). O método permite compensar as perdas de caráter resistivo em configurações toroidais de plasma, como os pinches de campo reverso (reversed field pinches - RFP). O problema pode ser reduzido ao estudo dos estados estacionários de uma coluna de plasma sujeita a campos de radiofrequência produzidos por bobinas helicoidais externas. Desprezando efeitos de gradientes de densidade e temperatura, o modelo é regido por um sistema de equações diferenciais ordinárias de segunda ordem não lineares acopladas, reguladas por quatro parâmetros adimensionais de interesse físico, que foram resolvidas numericamente usando o programa Mathematica. Estudou-se a eficiência do método em relação às aplicações em RFP, para os quais o campo magnético longitudinal apresenta uma inversão no interior da coluna de plasma. Isso implicou considerar regiões ainda não bem exploradas para os parâmetros de interesse. Os resultados numéricos são apresentados para configurações de campos magnéticos com simetria dipolar e quadrupolar / Abstract: Among the different methods, alternative to induction, to drive current in magnetically confined plasmas, with aim to obtain a continuous operation of a possible fusion reactor, we have studied the one associated to traveling magnetic field produced by helicoidal coils carrying out of phase radiofrequency currents (double helix current drive). The method allows compensating resistive losses in toroidal plasma configurations, like reversed field pinches. The problem may be reduced to the study of stationary states for a plasma column subjected to radiofrequency fields produced by external helicoidal coils. Neglecting density and temperature gradients, the model is governed by a system of coupled nonlinear second order ordinary differential equations, which depend on four dimensionless parameters of physical interest and can be solved numerically using the software Mathematica. We studied the efficiency of the method with respect to applications in reversed field pinches, for which the longitudinal steady magnetic field shows an inversion inside the plasma column. This implied considering not yet well explored regions of the parameters of interest. Numerical results are presented for magnetic field configurations of dipolar and quadrupolar simmetries / Mestrado / Física / Mestre em Física

Im Beitrag sind Überlegungen hinsichtlich der optimalen Geometrie des Kettengliedes dargestellt. Daraus wurde ein Innenglied mit zwei gewickelten Einlegern entwickelt. Das äußere Kettenglied entspricht dem einer Rollenkette. Die Geometrie der Einleger wurde mithilfe der FEM optimiert, sodass durch zwei Einleger aus Glasfaser die Dehnung auf ca. 57% bzw. für Kohlefaser auf ca. 39% reduziert werden konnte. / The article presents considerations regarding the optimal geometry of chain links. From this, an inner link with two wound inserts was developed. The outer chain link corresponds to that of a roller chain. The geometry of the inserts was optimized by a FEM analysis. With two inserts it is possible to reduce the elongation to approx. 57% (glass fiber) and approx. 39% (carbon fiber).

In der Lehrveranstaltung Bewegungstechnik & Bewegungsdesign für Verarbeitungsmaschinen werden die Studenten in die Lage versetzt, Systeme zur Bewegung von Arbeitsorganen in Verarbeitungs- und Textilmaschinen konstruktiv zu entwerfen und zu dimensionieren. Im Blickpunkt stehen zyklische Bewegungen, zu deren Realisierung auch der Einsatz von Mechanismen sinnvoll ist. Die interdisziplinäre Betrachtung der Bewegungstechnik dient als Einführung in die Problematik und als Grundlage für nachfolgende Optimierungen.

In this project we evaluated the perception of speedin a driving simulator. The study provides a preliminary survey that focuses onhow human beings can perceive moving in space. We have developed and implemented some techniques to study how we modify the perception of speed in adriving simulator. We targeted the driving perspective, trying to create certain effects in order to affect the perceived sense of speed. Changing the contrast of the scene we studied how the perception of the speed has been modified. Testing this modification we saw a change in the perception of the speed by the driver, who noticed an increase of the perceived speed through the alteration of the contrast of the scene.

DCU2 (Drive Control Unit 2) is an important control system used in applications for train systems that are configured by a set of parameters. Traditionally, parameterization is conducted by using an excel workbook during the software development. The parameters are set up and further export the parameters to the compilation step. Such approach has a number of disadvantages, e.g., delays on the validation and verification steps, system configuration overhead, and suboptimal system reliability generated by the parameter configurations. To improve the parameterization process, this thesis implements a model-based software architecture approach and automotive industry standards via rapid prototyping by using scrum methodology. We do this by using Matlab/Simulink, TDL (Time Description Language) and UML (Unified Modeling Language) architectural description languages to enable different views of the software architecture. We then develop different prototypes that implement ASAM (Association for Standardization of Automation and Measuring Systems) standards like XCP protocol over Ethernet (code ASAM MCD-1 XCP V1.1.0) and ASAP2 (code ASAM MCD-2 MC) in every scrum sprint. An evaluation then shows that the thesis successfully implements previously defined standards that use commercial tools from e.g., Vector, proving that the parameter‟s unit control can be handled via online calibration and measurement, leading to a significant improvement in Bombardier‟s software development process in a distributed development environment.

In der Lehrveranstaltung Bewegungstechnik & Bewegungsdesign für Verarbeitungsmaschinen werden die Studenten in die Lage versetzt, Systeme zur Bewegung von Arbeitsorganen in Verarbeitungs- und Textilmaschinen konstruktiv zu entwerfen und zu dimensionieren. Im Blickpunkt stehen zyklische Bewegungen, zu deren Realisierung auch der Einsatz von Mechanismen sinnvoll ist. Die interdisziplinäre Betrachtung der Bewegungstechnik dient als Einführung in die Problematik und als Grundlage für nachfolgende Optimierungen. Diese sind Gegenstand des Teils 2.

Electroencephalogram (EEG) is a well known, and well used method for studying brain activity, and it's possibilities have lately stretched into the car industry, were it's capabilities of detecting sleepiness in drivers are currently being put to the test. When performing EEG signal analysis on the brain, standardized signal bands exists that are characteristic to specific states of mind, such as when a driver is feeling sleepy. However, EEG as a method for studying the brain has major problems. The signal contains a lot of information that can be redundant or irrelevant, and the result is easily influenced and deviant by other parameters, that can cause incorrectness and inaccuracy in the final prediction and classification of the signal frame. One of the important methods for reducing this inaccuracy of EEG, and also reducing the computational cost of the diagnose, is feature selection. Finding key features in the signal, that can support a reliable diagnosis of a specific state of mind, is of great importance. Especially since learning systems, incorrectly predicting or interpreting a signal in the classification stage, can lead to incorrect triggering of safety features in futuristic cars, such as cruiser control. There are many existing feature selection algorithms available, and features that has been tried in different research project. The goal of this research was to help gather more accurate inputs from EEG, through an optimization study, and to increase the reliability of EEG. And by doing so, hopefully improve safety systems in cars, that in turn could help preventing sleepiness-related accidents on roads in the future. This was realized through a study of features, and feature selection algorithms. By determining key features that could distinguish sleepiness from a signal, as well as performing accuracy tests for different feature selection algorithms, the motivation for an optimal selection, based on the used parameters, could be made. However limited this research was, it concluded that Information Gain as a method for selecting features, was the most accurate algorithm, and that some features were better to use then others, such as Huguchi's fractal dimension, and the Hjorth complexity.

Molntjänsterna Dropbox, Google Drive, Microsoft OneDrive och Box har implementerats. Syftet med rapporten är att observera vilka problem som kan uppstå vid implementationen av molntjänsterna, och hur dessa problem kan lösas. Resultatet blev att molntjänsterna hade liknande problem. Problemen som uppstod var att alla molntjänster förutom Google Drive kunde bara öppna filväljaren i en popup. Att ange rätt domännamn blev ett problem för flera molntjänster då det var olika hur mycket av URLen som behövde anges, vilket berodde på respektive API.

This dissertation consists of three essays studying the economics of risky health behaviors. Essay 1 estimates the effects of Graduated Driver Licensing (GDL) restrictions on weight status among adolescents aged 14 to 17 in the U.S. The findings suggest that a night curfew significantly raises adolescents’ probability of being “overweight or obese” by 1.32 percentage points, corresponding to an increase in “overweight or obesity” rate of 4.8%. A night curfew combined with a passenger restriction increases this rate by 5.8%. Overall, I estimate that nearly 16% of the rise in “overweight or obesity” rate among teenagers aged 14 to 17 in the U.S from 1999 to 2015 can be explained by the presence of the GDL restrictions. In addition, the restrictions reduce teenagers’ exercise frequency while increasing their time spent watching TV, which may help to explain the adverse effects on obesity. Essay 2 exploits the effects of the Graduated Driver Licensing (GDL) restrictions on youth smoking and drinking. It finds that being subject to minimum entry age, a learner stage, or only a night curfew has no statistically significant effect whereas, interestingly, a night curfew combined with a passenger restriction reduces youth smoking and drinking. The estimated effects become more statistically significant and larger in magnitude in the medium run, which is in line with the addictive nature of these substances. Essay 3 investigates the underlying causes of suicide. It uses data from the U.S. at the county level and the primary methodology is a two-level Bayesian hierarchical model with spatially correlated random effects. The results show that the significant effects of observable factors on suicides found by earlier research may partially stem from excluding small area effects and time trends, without controlling for which the true contribution of unobserved propensities and time trends can be hidden within observable factors. Most importantly, a lot can be learned from unobserved yet persistent propensity toward suicide captured by the spatially correlated county specific random effects. Resources should be allocated to counties with high suicide rates, but also counties with low raw suicide rates but high unobserved propensities of suicide.

Modern electric machine drives, particularly three phase permanent magnet machine drive systems represent an indispensable part of high power density products. Such products include; hybrid electric vehicles, large propulsion systems, and automation products. Reliability and cost of these products are directly related to the reliability and cost of these systems. The compatibility of the electric machine and its drive system for optimal cost and operation has been a large challenge in industrial applications. The main objective of this dissertation is to find a design and control scheme for the best compromise between the reliability and optimality of the electric machine-drive system. The effort presented here is motivated by the need to find new techniques to connect the design and control of electric machines and drive systems. A highly accurate and computationally efficient modeling process was developed to monitor the magnetic, thermal, and electrical aspects of the electric machine in its operational environments. The modeling process was also utilized in the design process in form finite element based optimization process. It was also used in hardware in the loop finite element based optimization process. The modeling process was later employed in the design of a very accurate and highly efficient physics-based customized observers that are required for the fault diagnosis as well the sensorless rotor position estimation. Two test setups with different ratings and topologies were numerically and experimentally tested to verify the effectiveness of the proposed techniques. The modeling process was also employed in the real-time demagnetization control of the machine. Various real-time scenarios were successfully verified. It was shown that this process gives the potential to optimally redefine the assumptions in sizing the permanent magnets of the machine and DC bus voltage of the drive for the worst operating conditions. The mathematical development and stability criteria of the physics-based modeling of the machine, design optimization, and the physics-based fault diagnosis and the physics-based sensorless technique are described in detail. To investigate the performance of the developed design test-bed, software and hardware setups were constructed first. Several topologies of the permanent magnet machine were optimized inside the optimization test-bed. To investigate the performance of the developed sensorless control, a test-bed including a 0.25 (kW) surface mounted permanent magnet synchronous machine example was created. The verification of the proposed technique in a range from medium to very low speed, effectively show the intelligent design capability of the proposed system. Additionally, to investigate the performance of the developed fault diagnosis system, a test-bed including a 0.8 (kW) surface mounted permanent magnet synchronous machine example with trapezoidal back electromotive force was created. The results verify the use of the proposed technique under dynamic eccentricity, DC bus voltage variations, and harmonic loading condition make the system an ideal case for propulsion systems.