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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

Enhancing stroke generation and expressivity in robotic drummers - A generative physics model approach

Edakkattil Gopinath, Deepak 08 June 2015 (has links)
The goal of this master's thesis research is to enhance the stroke generation capabilities and musical expressivity in robotic drummers. The approach adopted is to understand the physics of human fingers-drumstick-drumhead interaction and try to replicate the same behavior in a robotic drumming system with the minimum number of degrees of freedom. The model that is developed is agnostic to the exact specifications of the robotic drummer that will attempt to emulate human like drum strokes, and therefore can be used in any robotic drummer that uses actuators with complete control over the motor position angle. Initial approaches based on exploiting the instability of a PID control system to generate multiple bounces and the limitations of this approach are also discussed in depth. In order to assess the success of the model and the implementation in the robotic platform a subjective evaluation was conducted. The evaluation results showed that, the observed data was statistically equivalent to the subjects resorting to a blind guess in order to distinguish between a human playing a multiple bounce stroke and a robot playing a similar kind of stroke.
2

Evaluation of the Structure of Levee Transitions on Wave Runup and Overtopping by Physical Modeling

Oaks, Drake Benjamin 2010 May 1900 (has links)
Coastal regions are continually plagued by high water levels induced by river flooding or hurricane induced storm surges. As with any protective structure, it is essential to understand potential problematic regions which could result in a devastating loss for the regions nations value most. Coastal protective systems are primarily comprised of floodwalls and levees, each of which has practiced methodologies utilized for estimating their performance under design conditions. Methodologies concerning spatial variability are limited however, and transitions where earthen levees merge with floodwalls are considered vulnerable areas to erosion and possible breaching. Physical modeling of a specified levee transition is undergone in a three-dimensional wave basin to evaluate this hypothesis, and the detailed results of this assessment are presented within this thesis. From the physical model testing, analysis of the data reveals that the overtopping rates of the levee transition tend to be larger than traditional overtopping techniques have predicted. The runup values and floodwall wave heights tend to show potential problematic areas and mimic the variation of overtopping along the levee transition. Under the design conditions tested, extreme overtopping conditions and associated water level values propose that in order for the structure to sustain the hydraulic conditions, it must be well protected. It is shown that the variation of the still water level plays the largest role in the magnitude of the measured values, and increasing the peak wave period and wave heights also yields greater overtopping and water levels at the structure. Overall these extreme overtopping rates and water levels experienced at the structure irrefutably expose a greater risk of erosion and breaching of the protective structure than initially predicted. This study highlights the need to understand specific spatial variability along coastal protective systems, and provides a better understanding of the mechanisms affecting overtopping for the specific structure tested.
3

Modeling of Power Consumption and Fault Tolerance for Electronic Textiles

Sheikh, Tanwir Abdulwahid 22 October 2003 (has links)
The developments in textile technology now enable the weaving of conductive wires into the fabrics. This allows the introduction of electronic components such as sensors, actuators and computational devices on the fabrics, creating electronic textiles (e-textiles). E-textiles can be either wearable or non-wearable. However, regardless of their form, e-textiles are placed in a tightly constrained design space requiring high computational performance, limited power consumption, and fault tolerance. The purpose of this research is to create simulation models for power consumption and fault behavior of e-textile applications. For the power consumption model, the power profile of the computational elements must be tracked dynamically based upon the power states of the e-textile components. For the fault behavior model, the physical nature of the e-textile and the faults developed can adversely affect the accuracy of results from the e-textile. Open and short circuit faults can disconnect or drain the battery respectively, affecting both battery life and the performance of the e-textile. This thesis describes the development of both of these models and their interfaces. It then presents simulation results of the performance of an acoustic beamforming e-textile in the presence and absence of faults, using those results to explore the battery life and fault tolerance of several battery configurations. / Master of Science
4

Physical Modeling and Numerical Analysis of Tsunami Inundation in a City Scale / 市街地スケールの津波浸水に関する水理模型実験と数値解析

Adi, Prasetyo 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20323号 / 工博第4260号 / 新制||工||1660(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 間瀬 肇, 教授 平石 哲也, 准教授 森 信人 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
5

Modélisation physique des cordes vocales pendant la phonation / Physical modeling of vocal folds stability during voicing

Haas, Jesse 07 December 2018 (has links)
On a pour but de faire de la modèlisation des plis vocaux avec des modèles physiques, et les vérifier en utilisant une maquette des plis vocaux. Cette recherche va contribuer à notre connaissance des mécanismes biomécaniques pendant la phonation normal aussi que pour la voix pathologique, et caracteriser la dificilité de la phonation sous certain conditions.On commence en montrent les calculs analytiques qui sert dans les modèles theoriques, qui sont des phénomènes mécanique et aerodynamique du bas. En suite on examine le réponse du modèle liée aux variations des paramètres pertinent à la voix normal aussi que pathologique. On fait aussi des simulations pour evaluer la stabilité en silico.On fini en comparant nos prédictions theoriques contre des données d'une maquette de plis vocaux compsée du latex et de l'eau aussi que le conduit vocal. / The goal of this thesis is to mathematically model and experimentally investigate theories of human larynx function using physical models and mechanical replicas. This research will help improve our knowledge of the biomechanics involved in normal voicing as well as in pathological voice in order to predict and characterize the ease of phonation under different conditions.We review the analytical calculations involved in the theoretical vocal folds model based on mechanical and aerodynamic phenomena within the glottis and vocal tract. We then explore the models response to variation of physical parameters pertinent to pathological and normal vocal conditions. We then evaluate the stability of the models computationally.The theoretical predictions are then compared to measurements performed on a latex-and-water mechanical replica of the larynx and of the vocal tract.
6

Modelação física em canal da geração de ondas regulares e irregulares para estudo de quebra-mar de enrocamento. / Quasi-steady and transient heat transfer mathematical model for electroslag remelting process.

Gireli, Tiago Zenker 20 December 2007 (has links)
Tendo em vista a importância das obras portuárias e costeiras no desenvolvimento do país e a complexidade dos fenômenos que regem os Processos Litorâneos, torna-se relevante a utilização de modelos físicos, como os canais de ondas, para otimização destes projetos. Neste sentido, os principais objetivos desta Tese são o desenvolvimento de um sistema de controle para o gerador de ondas do Laboratório de Hidráulica da Escola Politécnica da Universidade de São Paulo - LHEPUSP, capaz de gerar ondas irregulares, baseadas em espectros de energia da agitação, bem como, a partir de um estudo com caso de um molhe de berma, avaliar do ponto de vista técnico o procedimento de dimensionamento de quebra-mares com base no ensaio da estrutura frente a ondas regulares com as características da onda significativa de projeto. Uma das contribuições desta Tese é o novo sistema de controle da geração de ondas do LHEPUSP, que é capaz de gerar ondas regulares, irregulares e randômicas. A outra contribuição, referente ao estudo de caso, permitiu concluir que o emprego de ondas regulares na otimização em modelo físico de projetos de quebra-mares pode levar a dimensionamentos conservadores, e portanto de custo mais alto, principalmente no dimensionamento de obras dispostas em profundidades inferiores aos 10 m, onde foram encontradas diferenças para mais no recuo da estrutura, comparativamente com a ação de ondas irregulares de mesma altura significativa. / Considering the harbour and coastal structures significance for the Country development and the complex Littoral Processes phenomena, is an important requirement the physical models use, like wave flumes, to improve these designs. Following this context, the Thesis main purposes are to develop a wave maker control system for the Laboratório de Hidráulica da Escola Politécnica da Universidade de São Paulo - LHEPUSP wave fume able to generate irregular waves, based on wave energy spectra, and also, from a berm jetty case study, evaluate, from the technical point of view, the breakwater design procedure based on structure tests with design significative regular waves. One of the Thesis contribution is the new wave maker control system for the LHEPUSP wave fume able to generate regular, irregular and randomic waves. The other contribution, about the case study, showed as conclusion that the regular waves use for breakwaters design physical model improvement may suggest conservative results, inducing high cost structures, mainly for those ones in depths lower than 10 m, being observed larger structural backward response differences, comparing with irregular waves action with the same significative height.
7

Identification and Adaptive Control of a Coordinate Measuring Machine

Pettersson, Ulf January 2004 (has links)
<p>Important factors in manufacturing are quality and cost. Measuring machines play an important role for these fields. In order to meet higher demands on cost and accuracy, measuring machines can be constructed with weaker materials and increased mechanical flexibilities, and therefore there is a need to include the flexibilities in measuring machine models to obtain good performance. </p><p>The core theme in this thesis is modeling and idenfication of the physical parameters of drive mechanisms of a Brown&Sharpe Inc. Global A coordinate measuring machine. The approximation made is that the drive mechanisms can be described by a mass connected by springs, dampers and gear changes. It has been found that a one-spring model gives a reasonably good description of the studied CMM drive mechanism. The physical parameters of this model are identified using off-line algorithms. The algorithms are based on prediction error methods. For the off-line identification the MATLAB System Identification Toolbox and the bond graph representation is used. </p><p>The chosen model is then used for control. Traditional control and a Model-reference Adaptive System is derived and studied with the aim to increase the damping of CMM drive mechanisms. It is found that the adaptive system has very good disturbance rejection and can correct for drastic model errors. Another impact is that the damping of the studied drive mechanism can be increased with at least a factor of nine.</p>
8

Fysikalisk modellering av klimat i entreprenadmaskin / Physical Modeling of Climate in Construction Vehicles

Nilsson, Sebastian January 2005 (has links)
<p>This masters thesis concerns a modeling project performed at Volvo Technology in Gothenburg, Sweden. The main purpose of the project has been to develop a physical model of the climate in construction vehicles that later on can be used in the development of an electronic climate controller. The focus of the work has been on one type of wheel loader and one type of excavator. The temperature inside the compartment has been set equal to the notion climate. </p><p>With physical theories about air flow and heat transfer in respect, relations between the components in the climate unit and the compartment has been calculated. Parameters that has had unknown values has been estimated. The relations have then been implemented in the modeling tool Simulink. </p><p>The validation of the model has been carried out by comparison between measured data and modeled values by calculation of Root Mean Square and correlation. Varying the estimated parameters and identifying the change in the output signal, i.e the temperature of the compartment, have performed a sensitivity analysis. </p><p>The result of the validation has shown that the factor with the greatest influence on the temperature in the vehicle is the airflow through the climate unit and the outlets. Minor changes of airflow have resulted in major changes in temperature. The validation principally shows that the model gives a good estimation of the temperature in the compartment. The static values of the model differs from the values of the measured data but is regarded being as within an acceptable margin of error. The weakness of the model is mainly its predictions of the dynamics, which does not correlate satisfyingly with the data.</p>
9

Identification and Adaptive Control of a Coordinate Measuring Machine

Pettersson, Ulf January 2004 (has links)
Important factors in manufacturing are quality and cost. Measuring machines play an important role for these fields. In order to meet higher demands on cost and accuracy, measuring machines can be constructed with weaker materials and increased mechanical flexibilities, and therefore there is a need to include the flexibilities in measuring machine models to obtain good performance. The core theme in this thesis is modeling and idenfication of the physical parameters of drive mechanisms of a Brown&amp;Sharpe Inc. Global A coordinate measuring machine. The approximation made is that the drive mechanisms can be described by a mass connected by springs, dampers and gear changes. It has been found that a one-spring model gives a reasonably good description of the studied CMM drive mechanism. The physical parameters of this model are identified using off-line algorithms. The algorithms are based on prediction error methods. For the off-line identification the MATLAB System Identification Toolbox and the bond graph representation is used. The chosen model is then used for control. Traditional control and a Model-reference Adaptive System is derived and studied with the aim to increase the damping of CMM drive mechanisms. It is found that the adaptive system has very good disturbance rejection and can correct for drastic model errors. Another impact is that the damping of the studied drive mechanism can be increased with at least a factor of nine.
10

Fysikalisk modellering av klimat i entreprenadmaskin / Physical Modeling of Climate in Construction Vehicles

Nilsson, Sebastian January 2005 (has links)
This masters thesis concerns a modeling project performed at Volvo Technology in Gothenburg, Sweden. The main purpose of the project has been to develop a physical model of the climate in construction vehicles that later on can be used in the development of an electronic climate controller. The focus of the work has been on one type of wheel loader and one type of excavator. The temperature inside the compartment has been set equal to the notion climate. With physical theories about air flow and heat transfer in respect, relations between the components in the climate unit and the compartment has been calculated. Parameters that has had unknown values has been estimated. The relations have then been implemented in the modeling tool Simulink. The validation of the model has been carried out by comparison between measured data and modeled values by calculation of Root Mean Square and correlation. Varying the estimated parameters and identifying the change in the output signal, i.e the temperature of the compartment, have performed a sensitivity analysis. The result of the validation has shown that the factor with the greatest influence on the temperature in the vehicle is the airflow through the climate unit and the outlets. Minor changes of airflow have resulted in major changes in temperature. The validation principally shows that the model gives a good estimation of the temperature in the compartment. The static values of the model differs from the values of the measured data but is regarded being as within an acceptable margin of error. The weakness of the model is mainly its predictions of the dynamics, which does not correlate satisfyingly with the data.

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