abstract: It is possible in a properly controlled environment, such as industrial metrology, to make significant headway into the non-industrial constraints on image-based position measurement using the techniques of image registration and achieve repeatable feature measurements on the order of 0.3% of a pixel, or about an order of magnitude improvement on conventional real-world performance. These measurements are then used as inputs for a model optimal, model agnostic, smoothing for calibration of a laser scribe and online tracking of velocimeter using video input. Using appropriate smooth interpolation to increase effective sample density can reduce uncertainty and improve estimates. Use of the proper negative offset of the template function has the result of creating a convolution with higher local curvature than either template of target function which allows improved center-finding. Using the Akaike Information Criterion with a smoothing spline function it is possible to perform a model-optimal smooth on scalar measurements without knowing the underlying model and to determine the function describing the uncertainty in that optimal smooth. An example of empiric derivation of the parameters for a rudimentary Kalman Filter from this is then provided, and tested. Using the techniques of Exploratory Data Analysis and the "Formulize" genetic algorithm tool to convert the spline models into more accessible analytic forms resulted in stable, properly generalized, KF with performance and simplicity that exceeds "textbook" implementations thereof. Validation of the measurement includes that, in analytic case, it led to arbitrary precision in measurement of feature; in reasonable test case using the methods proposed, a reasonable and consistent maximum error of around 0.3% the length of a pixel was achieved and in practice using pixels that were 700nm in size feature position was located to within ± 2 nm. Robust applicability is demonstrated by the measurement of indicator position for a King model 2-32-G-042 rotameter. / Dissertation/Thesis / Measurement Results (part 1) / Measurement Results (part 2) / General Presentation / M.S. Mechanical Engineering 2012

Modelos matemáticos são comumente utilizados no estudo da dinâmica da água no solo não-saturado. A principal equação para se quantificar esta dinâmica é a equação diferencial de Richards. Sua solução direta é impossível na maioria dos casos, necessitando de métodos numéricos, dos quais se destaca a utilização das funções de condutividade e de retenção de água de Van Genuchten - Mualem para obtenção da solução numérica. Diante disto, o objetivo deste trabalho foi apresentar um novo método para a obtenção dos parâmetros de Van Genuchten - Mualem, que utiliza a modelagem inversa de dados de teores de água medidos periodicamente e obtidos por experimento de evaporação assistido por atenuação de radiação gama, para a modelagem inversa foi utilizado o software Hydrus-1D. O método foi testado em amostras com diferentes texturas, colhidas em 11 localidades na região de Piracicaba-SP. Dos conjuntos de exemplares analisados, apenas um apresentou resultado insatisfatório, concluindo que o método é válido / Mathematical models are commonly used in studies of water dynamics in unsaturated soil. The main equation to quantify water the dynamics is the differential Richards equation. Its analytical solution is impossible in almost all cases, requiring numerical methods, among which the Van Genuchten - Mualem water conductivity and water retention functions are frequently used to obtain the numerical solution. The objective of this work is to present a new method to obtain the Van Genuchten - Mualem parameters, using the inverse modeling of water content data measured periodically by gamma radiation attenuation in evaporating samples. Hydrus-1D software was used for the inverse modeling. The method was tested in samples with different textures, collected in 11 locations in the region of Piracicaba, state of São Paulo, Brazil. Of the sets of samples analyzed, only one presented an unsatisfactory result, concluding that the method is valid

Différentes applications de l'élasticité linéaire en géologie structurale sont présentées dans cette thèse à travers le développement de trois types de codes numériques. Le premier utilise la modélisation directe pour étudier les déplacements et champs de contraintes autour de zones faillées complexes. On montre que l'ajout de contraintes inégalitaires, telles que la friction de Coulomb, permet d'expliquer l'angle d'initiation des dominos dans les relais extensifs. L'ajout de matériaux hétérogènes et d'optimisations, telles la parallélisation sur processeurs multi-coeurs ainsi que la réduction de complexité des modèles, permettent l'étude de modèles beaucoup plus complexes. Le second type de code numérique utilise la modélisation inverse, aussi appelée estimation de paramètres. L'inversion linéaire de déplacements sur les failles ainsi que la détermination de paléo-contraintes utilisant une approche géomécanique sont développées. Le dernier type de code numérique concerne la restoration de structures complexes plissées et faillées. Il est notamment montré qu'une telle méthode permet de vérifier l'équilibre de coupes géologiques, ainsi que de retrouver la chronologie des failles. Finalement, nous montrons que ce même code permet de lisser des horizons 3D faillés, plissés et bruités en utilisant la géomécanique. / Different applications of linear elasticity in structural geology are presented in this thesis through the development of three types of numerical computer codes. The first one uses forward modeling to study displacement and perturbed stress fields around complexly faulted regions. We show that incorporating inequality constraints, such as static Coulomb friction, enables one to explain the angle of initiation of jogs in extensional relays. Adding heterogeneous material properties and optimizations, such as parallelization on multicore architectures and complexity reduction, admits more complex models. The second type deals with inverse modeling, also called parameter estimation. Linear slip inversion on faults with complex geometry, as well as paleo-stress inversion using a geomechanical approach, are developed. The last type of numerical computer code is dedicated to restoration of complexly folded and faulted structures. It is shown that this technique enables one to check balanced cross-sections, and also to retrieve fault chronology. Finally, we show that this code allows one to smooth noisy 3D interpreted faulted and folded horizons using geomechanics.

No description available.

Stamping dies are used in the Sheet Metal Forming (SMF) process for manufacturing of car body parts. The lead time for design and manufacturing of a stamping die is long, and therefore costly. In the final step of the manufacturing process, manual rework is performed to reach a desired pressure distribution on the forming surfaces in order to achieve a robust process and an approved part within tolerance. The main purpose for this work is to study and further develop a Virtual Rework Method that alters the shape of the forming surfaces of a die to compensate for the displacements of a stamping press that occur during stamping. Measurements were performed to obtain the displacements that occur in the stamping press during stamping. These measurements were performed on a double action deep drawing press of the brand Danly, located at Volvo Cars Tool & Die department in Olofström, Sweden. The measurement yields information of how the stamping press is deflecting and deforming during operation. The measurements are recorded with a Digital Image Correlation (DIC) system that records the displacements of the press during stamping. The displacements obtained in the measurements are then used as constraints to inverse FE- model a press table with topology optimization. This optimized press table is used in the Virtual Rework Method to be able to simulate both the deformations of the press and the internal deformations that occur in the die. Pre-simulations were performed before the measurements to ensure that the blank holder plate used in the measurements would withstand the applied blank holder force. These simulations also yield if the displacements were large enough for the ARAMIS DIC system to capture. The FE-model used in this work consisted of a die, blank holder, blank holder plate, outer ram and the optimized press table. The Virtual Rework Method was applied on the FE-model, where the result concludes that the altered shape of the deformed forming surfaces is almost identical to the shape of the nominal forming surfaces. However, an inversed modelled structure that represents the behavior of the outer ram is required to apply the Virtual Rework Method on the blank holder. This inversed modelled structure could be created from the displacements obtained in the measurements. To apply the Virtual Rework method on the punch, further measurements are required, where the position of the ARAMIS DIC system is altered, or an additional ARAMIS DIC system is used. / Pressverktyg används i plåtformningsprocessen vid tillverkning av karossdelar. Ledtiden för konstruktion och tillverkning av ett pressverktyg är lång och därför kostsam. I det sista steget i tillverkningsprocessen utförs manuell bearbetning för att nå en önskad tryckfördelning på formningsytorna, vilket ger en robust process och en godkänd del inom toleranserna. Huvudsyftet med detta arbetet är att studera och vidareutveckla en virtuell fläckningsmetod som korrigerar formningsytorna på dynan för att kompensera för de förskjutningar som uppstår i en stämplingspress under stämpling. Mätningar har utfördes för att erhålla förskjutning som uppstår i en stämplingspress under stämpling. Dessa mätningar utfördes på en dubbelverkande djupdragningspress av märket Danly, som finns hos Volvo Cars Tool & Die avdelning i Olofström, Sverige. Mätningen gav information om hur pressen deformeras under stämpling. Mätningarna registreras med ett Digital Image Correlation (DIC) system som registrerar pressens förskjutningar under stämpling. Förskjutningarna som erhållits i mätningarna användes sedan som randvillkor för en inversmodell för topologioptimering av ett pressbord. Detta optimerade pressbord används sedan i den Virtuella fläckningsmetoden för att kunna simulera både pressens stelkroppsrörelse och de interna deformationer som uppstår i pressverktyget. En förstudie utfördes innan mätningarna för att säkerställa att den plåthållarplattan som användes i mätningarna skulle motstå den applicerade plåthållarkraften. Denna förstudie gjordes även för att säkerhetsställa att förskjutningarna som uppstår i plåthållarplattan var stora nog för att ARAMIS DIC systemet skulle registrera dem. FE-modellerna som användes i detta arbete bestod av en dyna, plåthållare, plåthållarplatta, yttre slid och det optimerade pressbordet. Den Virtuella fläckningsmetoden applicerades på FE- modellen, där resultatet gav slutsatsen att den korrigerade formningsytan med applicerad belastning är nästintill identisk med formen på den nominella formningsytan. En inversmodellerad struktur som representerar beteendet hos den yttre sliden krävs emellertid för att tillämpa den Virtuella fläckningsmetoden på plåthållaren. Denna inversmodellerade struktur kunde erhållas från de förskjutning som erhölls i mätningarna. För att tillämpa den Virtuella fläckningsmetoden på stansen krävs ytterligare mätningar, där ARAMIS DIC systemets position ändras eller ett ytterligare ARAMIS DIC system används. / Reduced Lead Time through Advanced Die Structure Analysis - Vinnova

No description available.

One of the questions arising as regards to structured materials is how one can compute their cluster concentrations. Specifically, we are interested in deriving the concentrations of the micro-structures in the NMC (Nickel-Manganese-Cobalt) layer of the cathodes of Li-ion batteries. A simulated annealing approach has been used lately for detecting the structure of the whole lattice which is computationally heavy. Here we propose a mathematical model, called cluster approximation model, in the form of a dynamical system for describing the concentrations of different clusters inside the lattice. However, the dynamical system is hierarchical which requires to be truncated. Truncation of the hierarchical system is performed by the nearest-neighbor closure scheme. Also, a novel framework is proposed for an optimal closure of the dynamical system in order to enhance the accuracy of the model. The parameters of the model are reconstructed by the least square approach as a constrained optimization problem by minimizing the mismatch between the experimental data and the model outputs. The model is validated based on the experimental data on a known Li-ion battery cathode and different approximation schemes are compared. The results clearly show that the proposed approach significantly outperforms the conventional method. / Thesis / Master of Science (MSc)

One of the most significant challenges faced when modeling mass transfer from contaminant source zones is uncertainty regarding parameter estimates. These rate parameters are of particular importance because they control the connectivity between a simulated contaminant source zone and the aqueous phase. Where direct observation has fallen short, this study attempts to interpret field data using an inverse modeling technique for the purpose of constraining mass transfer processes which are poorly understood at the field scale. Inverse modeling was applied to evaluate parameters in rate-limited models for mass transfer. Two processes were analyzed: (i) desorption of hydrophobic contaminants and (ii) multicomponent Non-Aqueous Phase Liquid (NAPL) dissolution. Desorption was investigated using data obtained from elution experiments conducted with weathered sediment contaminated with 2,4,6 trinitrotoluene (TNT) (Sellm and Iskandar, 1994). Transport modeling was performed with four alternative source models, but predictive error was minimized by two first-order models which represented sorption/desorption using a Freundlich isotherm. The results suggest that first-order/Freundlich models can reproduce dynamic desorption attributed to high-and-low relative energy sorption sites. However, additional experimentation with the inversion method suggests that mass constraints are required in order to appropriately determine mass transfer coefficients and sorption parameters. The final portion of this research focused on rate-limited mass transfer from multicomponent NAPLs to the aqueous phase. Previous work has been limited to bench and intermediate scale findings which have been shown to inadequately translate to field conditions. Two studies were conducted in which numerical modeling was used to reproduce dissolution from multicomponent NAPL sources. In the first study, a model was generated to reproduce dissolution of chloroform (TCM), trichloroethylene (TCE) and tetrachloroethylene (PCE) observed during an emplaced-source field experiment conducted within a flow cell (Broholm et al., 1999). In the second study, a methodology was developed for analyzing benzene, toluene, ethylbenzene and xylene (BTEX) data during a field-scale mass transfer test conducted within a vertically-smeared source zone (Kavanaugh, 2010). The findings suggest that the inversion technique, when provided appropriate characterization of site and source parameters and when given appropriate dataset resolution, represents a viable method for parameter determination. Furthermore, the findings of this research suggest that inversion-based modeling provides an innovative predictive method for determining mass transfer parameters for multicomponent mixtures at the field scale. / Ph. D.

We improved the assimilated daily inversion method by conducting model simulation, satellite retrieval, and inverse modeling sequentially on a daily basis. The improved procedure was applied to GOME-2 and OMI NO₂ measurements over China in 2011, respectively. The new daily retrieval-inversion method significantly reduced the systematic bias in inverse modeling of NOₓ emission between using GOME-2 and OMI measurements, and detected more clear seasonal and weekly variations. OMI instrument observed NO₂ columns over China from 2005 to 2010 were analyzed in order to estimate the top-down anthropogenic NOₓ emission trends. The estimated average emission trend is slower than the trend reported for previous years. We find large regional, seasonal, and urban-rural variations in emission trends. These results appear to suggest that a number of factors have significantly reduced or even reversed the increasing trend of NOₓ emissions in more economically developed megacities and southern coastal regions, but their effects are not as significant in other major cities or less economically developed regions. A 1-D chemical transport model was applied to analyze OH and HO₂ radical observations during the Pacific Atmospheric Sulfur Experiment (PASE) near Christmas Island (Kiritimati, 1.52°N 157.24°W) from Aug. 2 through Sep. 10, 2007. In two of fourteen research flights, significantly higher HO₂/OH ratios in the buffer layer than the other flights were found. Model simulations indicated that fast-reacting oxygenated volatile organic compounds, which can react rapidly with OH and provide additional primary radical sources through photolysis, were necessary to explain the observations. During or right before these two flights, the WRF model simulated two strongest shallow convective events during this experiment, suggesting a transport pathway of ocean organics into the buffer layer. Ocean upwelling driven by atmospheric pressure depression during convection may expedite the release of ocean organics.

La vasière intertidale de Brouage, écosystème très étudié localement de longue date, a fait l’objet depuis 5 ans d’analyses plus approfondies notamment sur le devenir du biofilm microbien se formant à la surface des sédiments à marée basse. Ce travail de thèse s’inscrit dans cette optique. Il propose, par le couplage d’outils mathématiques et écologiques, d’analyser le réseau trophique de la vasière de Brouage sous différentes conditions abiotiques à partir de la synthèse des données les plus récentes. La modélisation inverse a permis d’estimer les flux manquants du réseau trophique. Les calculs d’indices d’analyse des réseaux écologiques ou ENA (Ecological Network Analysis) ont caractérisé la structure et le fonctionnement du réseau trophique.Un premier travail méthodologique, basé sur la dégradation-reconstruction d’un jeu de données très complet, a défini la meilleure fonction, la moyenne, pour le choix d’une seule solution pour chaque flux à la sortie de la modélisation inverse. La moyenne est la meilleure fonction puisque son utilisation aboutit à une bonne estimation des flux manquants quel que soit le niveau d’information intégré au modèle. Cette fonction permet aussi une bonne préservation de la structure et du fonctionnement du réseau trophique ainsi reconstruit. Le réseau trophique de la vasière de Brouage à basse mer a été étudié sous un aspect saisonnier par l’opposition de l’été et de l’hiver, l’hiver étant caractérisé par la présence d’oiseaux migrateurs sur la vasière. L’activité limicole des oiseaux est soutenue en hiver par une forte production du microphytobenthos et un fort recyclage de la matière. L’organisation interne et la spécialisation des flux restent cependant semblables pour les deux saisons considérées. Dans un deuxième temps, le réseau trophique à pleine mer en été a été modélisé sous différentes conditions hydrodynamiques permettant ou pas la remise en suspension du biofilm microbien. La comparaison entre ces deux situations met en évidence l’effet de la remise en suspension sur le couplage benthos-pelagos. Le système soumis à la remise en suspension présente un très faible indice de recyclage lié à la faible intégration au réseau trophique pélagique du carbone particulaire benthique remis en suspension. De plus, la remise en suspension provoque une augmentation de l’activité du système couplée à une faible spécialisation des flux, ce qui est supposé déstabiliser le système. / The Brouage mudflat is an intertidal ecosystem which has been studied locally for a long time. During the last 5 years, in depth studies have especially focused on the fate of the microbial biofilm which develops at the surface of the sediments at low tide. The present Ph.D. work was accomplished in this framework. It proposes, through the synthesis of the most recent data, to combine mathematical and ecological tools to analyze the Brouage food web under different abiotic conditions. The inverse modeling allowed estimating the unknown flows of the food web. The calculation of the ENA (Ecological Network Analysis) indices characterized the structure and the functioning of the food web. A methodological work, based on the degradation/reconstruction of a complete data set, determined the best function, the mean, to choose a single solution for each flow among the set of values estimated by the inverse modeling. The mean is the best function because it leads to a good estimation of the unknown flows irrespective of the quantity of information integrated in the model. Moreover, this function allows a good conservation of the structure and functioning of the reconstructed food web.The Brouage food web at low tide was investigated with a seasonal approach by the opposition of the summer and the winter food webs, the latest being characterized by the presence of migratory shorebirds. The shorebird activity is sustained by a strong primary production and a strong recycling. Nevertheless, the internal organization and the specialization remain similar for the two seasons. In a second step, the food web at high tide was modeled under different hydrodynamical conditions sufficient or not to induce the resuspension of the microbial biofilm. The comparison between the two food webs highlights the effect of the resuspension on the benthos-pelagos coupling. The recycling activity is low due to the low integration of the resuspended benthic particulate carbon in the pelagic food web during resuspension. Additionally, the resuspension leads to an increase of the activity of the whole system coupled with a drop of the specialization of the trophic pathways that is supposed to destabilize the system.