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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.
61

3D Capacitance Extraction With the Method of Moments

Li, Tao 14 January 2010 (has links)
In this thesis, the Method of Moments has been applied to calculate capacitance between two arbitrary 3D metal conductors or a capacitance matrix for a 3D multi-conductor system. Capacitance extraction has found extensive use for systems involving sets of long par- allel transmission lines in multi-dielectric environment as well as integrated circuit package including three-dimensional conductors located on parallel planes. This paper starts by reviewing fundamental aspects of transient electro-magnetics followed by the governing dif- ferential and integral equations to motivate the application of numerical methods as Method of Moments(MoM), Finite Element Method(FEM), etc. Among these numerical tools, the surface-based integral-equation methodology - MoM is ideally suited to address the prob- lem. It leads to a well-conditioned system with reduced size, as compared to volumetric methods. In this dissertation, the MoM Surface Integral Equation (SIE)-based modeling approach is developed to realize electrostatic capacitance extraction for 3D geometry. MAT- LAB is employed to validate its e?ciency and e?ectiveness along with design of a friendly GUI. As a base example, a parallel-plate capacitor is considered. We evaluate the accu- racy of the method by comparison with FEM simulations as well as the corresponding quasi-analytical solution. We apply this method to the parallel-plate square capacitor and demonstrate how far could the undergraduate result 0C = A ? "=d' be from reality. For the completion of the solver, the same method is applied to the calculation of line capacitance for two- and multi-conductor 2D transmission lines.
62

Classificação de imagens de satélite por aglomeração hierárquica usando o MatLab

Castro, Maria Luísa de Morais e Sousa de January 2006 (has links)
No description available.
63

Performance do perfume : modelagem e simulação da evaporação/difusão

Carneiro, Ana Clara Soares January 2012 (has links)
Tese de Mestrado Integrado. Engenharia Química. Faculdade de Engenharia. Universidade do Porto. 2012
64

Equilibration of D-Glucaric Acid in Aqueous Solution

Brown, Jolene Mary January 2007 (has links)
Abstract The equilibrium of aqueous D-glucaric acid was investigated via Nuclear Magnetic Resonance (NMR) spectroscopy. The NMR spectra of all four species (D-glucaric acid, D-glucaro-1,4-lactone, D-glucaro-6,3- lactone and D-glucaro-1,4;6,3-lactone) were assigned. A 1H NMR spectroscopy method was developed to investigate the kinetics of equilibration of the starting species (D-glucaro-1,4-lactone and D-glucaro-1,4;6,3-dilactone). The equilibration was investigated under neutral conditions as well as conditions with increasing acidity. Each experiment set contained 50-100 1HNMR spectroscopy experiments that were run on the same sample using a program that built in delays. Dimethyl sulfoxide was used as an internal standard, and its signal size was used as a scale to report the changes in relative concentration of the four species throughout the experiment sets. Under neutral conditions D-glucaro-1,4-lactone is relatively stable against equilibration, while D-glucaro-1,4;6,3-dilactone is not. Under acidic conditions both compounds equilibrate within approximately 30,000 seconds. After equilibration under acidic conditions D-glucaric acid is the dominant species, while the relative concentration of D-glucaro-1,4-lactone is slightly higher than that of D-glucaro-6,3-lactone. The relative equilibrium concentration of D-glucaro-1,4;6,3-dilactone is low. A mechanism for the equilibration of aqueous D-glucaric acid was proposed and equilibrium constants and estimates of rate constants were derived from the experimental data. These rate constants were used in MATLAB simulations that were compared to the experimental data. MATLAB simulations were used to alter the rate constants to improve the fits between experimental data and simulated data.
65

A Cadence layout wrapper for MATLAB

Tsirepli, Ismini January 2006 (has links)
<p>In this thesis, the focus is on creating a wrapper between MATLAB and the Cadence Virtuoso design environment. The central idea is to use the wrapper and write the code for an entire analog layout as scripts in MATLAB. Basically, we will implement a set of necessary commands for performing the most fundamental tasks in layout generation from within MATLAB.</p>
66

Utveckling av modell för kvalitetsstyrning av polyetenreaktor

Larsson, Katarina January 2003 (has links)
No description available.
67

Advanced control of a remotely operated underwater vehicle

Bernhard, Jacob, Johansson, Patrik January 2012 (has links)
Remotely Operated underwater Vehicles (ROVs) are getting more and more advanced withevery new model. As new functionality is added, the price increases. This thesis is one partof a larger project, where the goal is to develop a low-budget ROV. The ROV should later bemade autonomous and entered into a competition.This thesis have focused on the modeling and stabilizing control of an ROV that was designedby mechanical engineering students at Linköping University. The only sensor used was anInertial Measurement Unit (IMU) and the ROV has a torpedo-like design. The modeling wasdone using identification in Matlab with the grey box and black box methods. Water trialsand simulations show that the model is estimated sufficiently good to be used as the basis ofdifferent model based controllers.Two different control strategies were implemented; a linear quadratic controller (LQ) and amodel predictive controller (MPC). Both controllers worked desirably in simulations. Onlythe LQ controller was evaluated in real world tests. Due to problems with the implementationenvironment chosen for the MPC, the MPC could not be tested.The thesis also uses decision matrices as a mean to motivate the important decisions thathave been made.
68

Modeling and Simulation of A Hybrid Electric Vehicle Using MATLAB/Simulink and ADAMS

Fan, Brian Su-Ming January 2007 (has links)
As the global economy strives towards clean energy in the face of climate change, the automotive industry is researching into improving the efficiency of automobiles. Hybrid vehicle systems were proposed and have demonstrated the capability of reducing fuel consumption while maintaining vehicle performance. Various hybrid vehicles in the form of parallel and series hybrid have been produced by difference vehicle manufacturers. The purpose of this thesis is to create a hybrid vehicle model in MATLAB and ADAMS to demonstrate its fuel economy improvement over a conventional vehicle system. The hybrid vehicle model utilizes the Honda IMA (Integrated Motor Assist) architecture, where the electric motor acts as a supplement to the engine torque. The motor unit also acts as a generator during regenerative braking to recover the otherwise lost kinetic energy. The powertrain components’ power output calculation and the control logic were modeled in MATLAB/Simulink, while the mechanical inertial components were modeled in ADAMS. The model utilizes a driver input simulation, where the driver control module compares the actual and desired speeds, and applies a throttle or a braking percent to the powertrain components, which in turns applies the driving or the braking torque to the wheels. Communication between MATLAB and ADAMS was established by ADAMS/Controls. In order to evaluate the accuracy of the MATLAB/ADAMS hybrid vehicle model, simulation results were compared to the published data of ADVISOR. The West Virginia University 5 Peaks drive cycle was used to compare the two software models. The results obtained from MATLAB/ADAMS and ADVISOR for the engine and motor/generator correlated well. Minor discrepancies existed, but were deemed insignificant. This validates the MATLAB/ADAMS hybrid vehicle model against the published results of ADVISOR. Fuel economy of hybrid and conventional vehicle models were compared using the EPA New York City Cycle (NYCC) and the Highway Fuel Economy Cycle (HWFET). The hybrid vehicle demonstrated 8.9% and 14.3% fuel economy improvement over the conventional vehicle model for the NYCC and HWFET drive cycles, respectively. In addition, the motor consumed 83.6kJ of electrical energy during the assist mode while regenerative braking recovered 105.5kJ of electrical energy during city driving. For the highway drive cycle, the motor consumed 213.6kJ of electrical energy during the assist mode while the regenerative braking recovered 172.0kJ of energy. The MATLAB/ADAMS vehicle model offers a simulation platform that is modular, flexible, and can be conveniently modified to create different types of vehicle models. In addition, the simulation results clearly demonstrated the fuel economy advantage of the hybrid vehicle over the conventional vehicle model. It is recommended that a more sophisticated power management algorithm be implemented in the model to optimize the efficiencies of the engine and the motor/generator. Furthermore, it is suggested that the ADAMS vehicle model be validated against an actual vehicle, in order to fully utilize the multi-body vehicle dynamics capability which ADAMS has to offer.
69

Utveckling av modell för kvalitetsstyrning av polyetenreaktor

Larsson, Katarina January 2003 (has links)
No description available.
70

Visual Stimulus Development : FlyFly - A user friendly interface for MatLaba nd the Psychophysics toolbox

Henriksson, Jonas January 2010 (has links)
Flies use visual cues for a variety of tasks, such as maneuvering through the environment and finding potential mates. Hoverflies, in particular, have very developed eyes and use them to be able to hover mid air and perform fast, elegant movements. The Motion Vision Group, located at the Department of Neuroscience at BMC, Uppsala, studies the motion vision system of the hoverfly brain, using electrophysiology. Experiments are performed by displaying visual stimuli on a screen in front of an immobilized fly, while recording the response from a single neuron with a thin electrode.Until now, the Motion Vision group has been using the open source program VisionEgg to generate the stimuli. VisionEgg is able to display stimuli at high frame rate and has a large set of useful features such as perspective distortion. It also has a lot of drawbacks that makes it desirable to acquire new software. The main drawbacks include it being hard to learn, use and modify, as well as being unable to generate the stimuli needed for some key experiments.This master´s thesis describes the development of software more suited to the lab´s needs. This software should be able to generate some of the stimuli that were impossible to do at the moment, as well as being easy to expand and add upon. The frame rate of the displayed stimuli has to be both high and stable in order to perform high precision experiments.The resulting program is called FlyFly and has been developed iteratively in close cooperation with its end users, ensuring a user friendly end product capable of meeting the lab´s needs. FlyFly is implemented using MatLab and the Psychophysics toolbox with the graphical user interface (GUI) designed with the Guide editor. The GUI is decoupled from the functions drawing the stimuli, making it easy to improve or remove parts altogether. FlyFly is intuitive to use and allows anyone to quickly get started. It allows easy manipulation of series of trials, and supports drawing of multiple objects simultaneously. With the current machine set-up, it displays stimuli at 160 frames per second with few or no dropped frames.FlyFly is currently being used in the lab and will be so for the foreseeable future.

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