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Kurvenabgleich zur Bestimmung eines Systemverhaltens und von MaterialparameternKallmeyer, Rene 07 June 2017 (has links) (PDF)
Das Systemverhalten eines Einsteckvorganges und anschließenden Haltevorganges soll bestimmt werden. Bei den zu untersuchenden Komponenten sollen die Einpresskraft und die Haltekraft einem gewünschten Systemverhalten entsprechen. Zur Einstellung des gewünschten Systemverhaltens werden die Geometrieparameter variiert.
Zuvor wird das Werkstoffverhalten der Komponenten kalibriert. Die vorliegende Spannungs-Dehnungs-Kurve aus einem Zugversuch wird benötigt zur Beschreibung eines Werkstoffverhaltens.
Bei dieser Fragestellung geht es um die Parameteridentifikation für ein nichtlineares Materialmodell aus Ansys Workbench. Die Ergebnisse der Zugversuche werden als Referenzsignale in das Signal Processing eingelesen. Die in diesem Materialmodell vorhandenen Materialparameter sind so anzupassen, dass die numerischen Ergebnisse möglichst gut mit den experimentell gewonnenen Daten aus den Versuchen übereinstimmen.
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Development of a Software Code for Pharmacokinetic Analysis of PET Data.Shamas, Sofia 01 January 2006 (has links)
To improve efficacy in the field of drug discovery simpler in vivo, non invasive methods such as PET and SPECT are used. Pharmacokinetic analysis is the underlying method for analyzing the PET data. Imaging of tracer distribution is used to study a metabolic process. Using Matlab as the programming language, a software tool is developed to analyze the quantitative information from PET and to obtain an estimate of pharmacokinetic parameters, representing the bio- distribution of the radiotracer. A Graphical User Interface developed allows two types of analysis, depending upon the nature of the radiotracer: Compartmental Modeling and Logan Plot Analysis. Compartmental analysis gives us rate constants and blood volume where as Logan analysis gives us the distribution volume as the parameter of interest. Code validation is done for two radiotracers, 15O-water (Single compartment model) and FPAC (Logan Plot). Results from the code were compared with those obtained during a research work done to study MDR.
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Nonlinear Regression of Power-Exponential Functions : Experiment Design for Curve FittingDenka, Tshering January 2017 (has links)
This thesis explores how to best choose data when curve fitting using power exponential functions. The power exponential functions used are μ(b; x)=(xe1-x)b and Φ(ρ; x)=((1-x)ex)ρ . We use a number of designs such as the equidistant design, the Chebyshev design and the the D-optimal design to compare which design gives the best fit. A few examples including the logistic and the heidler function are looked at during the comparison. The measurement of the errors were made based on the sum of least squares errors in the first part and the maximum error in the second part. MATLAB was used in this comparison.
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Eliminação de artefatos de estímulo em potenciais evocados somatossensitivos. / Removal of stimulus artifact in somatosensory evoked potentials.Oyama, Alberto Mitsuo 09 November 2010 (has links)
Os potenciais evocados têm uma consagrada utilização em clínica. Sua obtenção é dificultada pela presença de outros sinais biológicos, de artefatos de movimento, de ruído eletrônico, de interferência da rede elétrica e de artefatos de estímulo. A média síncrona ou promediação é um método que elimina os sinais que não estejam sincronizados com a estimulação, incluindo os outros sinais biológicos, os artefatos de movimento, o ruído e a interferência. No entanto, esse método não consegue eliminar os artefatos de estímulo. Outros métodos devem ser usados para essa tarefa. Para esses métodos, a eliminação do artefato de estímulo é bem sucedida quando o artefato não se sobrepõe ao potencial evocado. Porém, para uma captação próxima ao local de estimulação, a sobreposição ocorre e dificulta a eliminação do artefato de estímulo. O objetivo deste trabalho foi o de estudar a variação da amplitude e latência do pico do potencial evocado e sua influência nas estimativas da amplitude, da latência e do erro quadrático médio. Para potenciais evocados em que houve sobreposição com o artefato, o erro médio quadrático sempre foi reduzido com a remoção do artefato de estímulo. O erro de medição da latência foi reduzido a praticamente zero, independentemente da amplitude do potencial evocado. Por outro lado, o método inseriu erro na medição da amplitude de potenciais evocados grandes. Por isso, nesse caso específico de atraso pequeno e amplitude grande, a medição da amplitude deve ser feita diretamente no sinal antes da remoção do artefato de estímulo. Comparando a ocorrência de sobreposição com os locais de captação do potencial evocado, pode-se afirmar que, para o modelo de artefato de estímulo usado neste trabalho, a necessidade de se aplicar o procedimento de remoção de artefato se restringiu aos potenciais evocados captados no cotovelo, para estimulação do nervo mediano tanto no punho quanto na mão. / Evoked potentials have been used in clinics. Their measurement is hindered by the presence of other biological signals, movement artifacts, electronic noise, power-line interference, and stimulus artifacts. Synchronous averaging is a method that eliminates the signals that are not synchronized with the stimulation, including other biological signals, movement artifacts, noise and interference. However, this method fails to eliminate stimulus artifacts. Other methods must be used in this task. Using these methods, one can obtain success in the stimulus artifact elimination, whenever the artifact does not superimpose with the evoked potential. Nevertheless, for a measurement close to the stimulation site, the superimposition is a fact that hinders the elimination of the stimulus artifact. The objective of this Masters thesis was to study the variation of the amplitude and latency of an evoked potential and verify their influence on the amplitude and latency estimates, as well as on the mean square error. For evoked potentials in which there was superposition, the mean square error was always reduced by the removal of the stimulus artifact. Latency measurement errors were reduced to zero, regardless of the evoked potential amplitude. However, this method inserted amplitude measurement errors for large evoked potentials. So, in the case of short delays and large amplitudes, amplitude measurements should be performed directly on the signal, before stimulus artifact removal. By comparing the presence of superposition with the evoked potential recording sites, one may state that, for the stimulus artifact model used in this work, the need to apply the artifact removal procedure was restricted to the evoked potentials recorded on the elbow, for median nerve stimulation both on wrist and hand.
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Atomic Force Microscopy: Lateral-Force Calibration and Force-Curve AnalysisAnderson, Evan V 26 April 2012 (has links)
This thesis reflects two advances in atomic force microscopy. The first half is a new lateral force calibration procedure, which, in contrast to existing procedures, is independent of sample and cantilever shape, simple, direct, and quick. The second half is a high-throughput method for processing, fitting, and analyzing force curves taken on Pseudomonas aeruginosa bacteria in an effort to inspire better care for statistics and increase measurement precision.
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Some techniques of data analysisNussbaum, Jeremy Howard January 1979 (has links)
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Jeremy Howard Nussbaum. / B.S.
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Determinação da curva aproximadora pela composição de curvas de Bézier e aplicação do recozimento simulado. / Curve fitting by composition of Bezier curves and simulated annealingUeda, Edson Kenji 12 February 2015 (has links)
Determinar curvas a partir de uma série da pontos é uma tarefa importante e muito utilizada em CAD. Este trabalho propõe um algoritmo para determinar uma curva aproximadora representada por diversas curvas de Bézier em sequência a partir de uma sequência de pontos. É utilizada uma abordagem de curvas de Bézier por trechos, onde cada trecho possui continuidade C1-fraca. A otimização é feita pelo recozimento simulado com vizinhança adaptativa que minimiza a soma das distâncias de cada ponto da sequência à curva aproximadora e utiliza o comprimento da curva aproximadora como um fator de regularização. Adicionalmente, é utilizado o recozimento simulado multi-objetivo que avalia a influência da soma das distâncias de cada ponto à curva e do comprimento da curva separadamente. Também é feita uma comparação entre a técnica de ajuste de curvas e a técnica de interpolação de curvas. / The task of determining a curve from a set of points is very important in CAD. This work proposes an algorithm to determine a sequence of Bézier curves that approximate a sequence of points. The piecewise Bézier curve is used, where each curve has C1- weak continuity. The optimization is done using the simulated annealing with adaptive neighborhood aiming at minimizing the sum of the distances from each point of the sequence to the generated curve. The length of this curve is used as a regularization factor. In addition, it is used a multi-objective simulated annealing that evaluates the influence of the sum of the distances from each point to the generated curve, and the curves length. It is also done a comparison between curve fitting and curve interpolation techniques.
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Eliminação de artefatos de estímulo em potenciais evocados somatossensitivos. / Removal of stimulus artifact in somatosensory evoked potentials.Alberto Mitsuo Oyama 09 November 2010 (has links)
Os potenciais evocados têm uma consagrada utilização em clínica. Sua obtenção é dificultada pela presença de outros sinais biológicos, de artefatos de movimento, de ruído eletrônico, de interferência da rede elétrica e de artefatos de estímulo. A média síncrona ou promediação é um método que elimina os sinais que não estejam sincronizados com a estimulação, incluindo os outros sinais biológicos, os artefatos de movimento, o ruído e a interferência. No entanto, esse método não consegue eliminar os artefatos de estímulo. Outros métodos devem ser usados para essa tarefa. Para esses métodos, a eliminação do artefato de estímulo é bem sucedida quando o artefato não se sobrepõe ao potencial evocado. Porém, para uma captação próxima ao local de estimulação, a sobreposição ocorre e dificulta a eliminação do artefato de estímulo. O objetivo deste trabalho foi o de estudar a variação da amplitude e latência do pico do potencial evocado e sua influência nas estimativas da amplitude, da latência e do erro quadrático médio. Para potenciais evocados em que houve sobreposição com o artefato, o erro médio quadrático sempre foi reduzido com a remoção do artefato de estímulo. O erro de medição da latência foi reduzido a praticamente zero, independentemente da amplitude do potencial evocado. Por outro lado, o método inseriu erro na medição da amplitude de potenciais evocados grandes. Por isso, nesse caso específico de atraso pequeno e amplitude grande, a medição da amplitude deve ser feita diretamente no sinal antes da remoção do artefato de estímulo. Comparando a ocorrência de sobreposição com os locais de captação do potencial evocado, pode-se afirmar que, para o modelo de artefato de estímulo usado neste trabalho, a necessidade de se aplicar o procedimento de remoção de artefato se restringiu aos potenciais evocados captados no cotovelo, para estimulação do nervo mediano tanto no punho quanto na mão. / Evoked potentials have been used in clinics. Their measurement is hindered by the presence of other biological signals, movement artifacts, electronic noise, power-line interference, and stimulus artifacts. Synchronous averaging is a method that eliminates the signals that are not synchronized with the stimulation, including other biological signals, movement artifacts, noise and interference. However, this method fails to eliminate stimulus artifacts. Other methods must be used in this task. Using these methods, one can obtain success in the stimulus artifact elimination, whenever the artifact does not superimpose with the evoked potential. Nevertheless, for a measurement close to the stimulation site, the superimposition is a fact that hinders the elimination of the stimulus artifact. The objective of this Masters thesis was to study the variation of the amplitude and latency of an evoked potential and verify their influence on the amplitude and latency estimates, as well as on the mean square error. For evoked potentials in which there was superposition, the mean square error was always reduced by the removal of the stimulus artifact. Latency measurement errors were reduced to zero, regardless of the evoked potential amplitude. However, this method inserted amplitude measurement errors for large evoked potentials. So, in the case of short delays and large amplitudes, amplitude measurements should be performed directly on the signal, before stimulus artifact removal. By comparing the presence of superposition with the evoked potential recording sites, one may state that, for the stimulus artifact model used in this work, the need to apply the artifact removal procedure was restricted to the evoked potentials recorded on the elbow, for median nerve stimulation both on wrist and hand.
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Modeling and Parameter Estimation of Sea Clutter Intensity in Thermal NoiseJanuary 2019 (has links)
abstract: A critical problem for airborne, ship board, and land based radars operating in maritime or littoral environments is the detection, identification and tracking of targets against backscattering caused by the roughness of the sea surface. Statistical models, such as the compound K-distribution (CKD), were shown to accurately describe two separate structures of the sea clutter intensity fluctuations. The first structure is the texture that is associated with long sea waves and exhibits long temporal decorrelation period. The second structure is the speckle that accounts for reflections from multiple scatters and exhibits a short temporal decorrelation period from pulse to pulse. Existing methods for estimating the CKD model parameters do not include the thermal noise power, which is critical for real sea clutter processing. Estimation methods that include the noise power are either computationally intensive or require very large data records.
This work proposes two new approaches for accurately estimating all three CKD model parameters, including noise power. The first method integrates, in an iterative fashion, the noise power estimation, using one-dimensional nonlinear curve fitting,
with the estimation of the shape and scale parameters, using closed-form solutions in terms of the CKD intensity moments. The second method is similar to the first except it replaces integer-based intensity moments with fractional moments which have been shown to achieve more accurate estimates of the shape parameter. These new methods can be implemented in real time without requiring large data records. They can also achieve accurate estimation performance as demonstrated with simulated and real sea clutter observation datasets. The work also investigates the numerically computed Cram\'er-Rao lower bound (CRLB) of the variance of the shape parameter estimate using intensity observations in thermal noise with unknown power. Using the CRLB, the asymptotic estimation performance behavior of the new estimators is studied and compared to that of other estimators. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019
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Circular motion for robotized metal deposition : verification and implementationDenys, Kristof January 2013 (has links)
Metal deposition is an additive layered manufacturing process that deposits molten metal droplets on a substrate and by repeating this process layer by layer, a complex shaped 3D geometry can be manufactured. In this thesis, the metal deposition process is performed by a robot with a wire feeder tool and a laser as energy source to melt the metal wire. The robot programming for robotized metal deposition process can be completely automated by computer aided robotics software. University West is currently developing an add-in application in a computer aided robotics software, Process Simulate, that is capable of programming the robotized metal deposition process. The first goal of this thesis was to verify the up to now developed software and the process from CAD drawing down to robot code. Another goal was to find and implement an algorithm that will reduce the number of locations on a circular arc to three locations. The algorithm to minimize the locations must be capable of changing all the different curvature paths to linear and circular arc motions which are easy to translate to robot code. The user should be able to decide the fitting precision of the approximated motion path to the original path. A real robot cell setup is modelled in Process Simulate. This lets Process Simulate generate the correct robot code for that specific cell. Since each robot cell has its own unique setup, a custom script will be developed that changes the universal robot code, that Process Simulate generates, to the custom robot code required in this specific robot cell. The software is improved and tested from CAD drawing down to robot code but still needs to be debugged more and needs implementation of some non-existing features.
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