A validação de modelos lineares é uma etapa importante em um projeto de Identificação de Sistemas, pois a escolha correta do modelo para representar a maior parte da dinâmica do processo, dentro de um número finito de técnicas de identificação e em torno de um ponto de operação, permite o sucesso no desenvolvimento de controladores preditivos e de controladores robustos. Por tal razão, o objetivo principal desta Tese é o desenvolvimento de um método de validação de modelos lineares, tendo como ferramentas de avaliação os métodos estatísticos, avaliações dinâmicas e análise da robustez do modelo. O componente principal do sistema de validação de modelos lineares proposto é o desenvolvimento de um sistema fuzzy para análise dos resultados obtidos pelas ferramentas utilizadas na etapa de validação. O projeto de Identificação de Sistemas é baseado em dados reais de operação de uma Planta-Piloto de Neutralização de pH, localizada no Laboratório de Controle de Processos Industriais da Escola Politécnica da USP. Para verificar o resultado da validação, todos os modelos são testados em um controlador preditivo do tipo QDMC (Quadratic Dynamic Matrix Control) para seguir uma trajetória de referência. Os critérios utilizados para avaliar o desempenho do controlador QDMC, para cada modelo utilizado, foram a velocidade de resposta do controlador e o índice da mínima variabilidade da variável de processo. Os resultados mostram que a confiabilidade do sistema de validação projetado para malhas com baixa e alta não-linearidade em um processo real, foram de 85,71% e 50%, respectivamente, com relação aos índices de desempenho obtidos pelo controlador QDMC. / Linear model validation is the most important stage in System Identification Project because, the model correct selection to represent the most of process dynamic allows the success in the development of predictive and robust controllers, within identification technique finite number and around the operation point. For this reason, the development of linear model validation methods is the main objective in this Thesis, taking as a tools of assessing the statistical, dynamic and robustness methods. Fuzzy system is the main component of model linear validation system proposed to analyze the results obtained by the tools used in validation stage. System Identification project is performed through operation real data of a pH neutralization pilot plant, located at the Industrial Process Control Laboratory, IPCL, of the Escola Politécnica of the University of São Paulo, Brazil. In order to verify the validation results, all modes are used in QDMC type predictive controller, to follow a set point tracking. The criterions used to assess the QDMC controller performance were the speed response and the process variable minimum variance index, for each model used. The results show that the validation system reliability were 85.71% and 50% projected for low and high non-linearity in a real process, respectively, linking to the performance indexes obtained by the QDMC controller.

Com os grandes avanços recentes dos sistemas computacionais, houve a possibilidade de ascensão de dispositivos inovadores, como os modernos telefones celulares e tablets com telas sensíveis ao toque. Para gerenciar adequadamente estas diversas interfaces é necessário utilizar o software dependente do hardware (HdS), que é responsável pelo controle e acesso a estes dispositivos. Além deste complexo arranjo de componentes, para atender a crescente demanda por mais funcionalidades integradas, o paradigma de multiprocessamento vem sendo adotado para aumentar o desempenho das plataformas. Devido à lacuna de produtividade de sistemas, tanto a indústria como a academia têm pesquisado processos mais eficientes para construir e simular sistemas cada vez mais complexos. A premissa dos trabalhos do estado da arte está em trabalhar com modelos com alto nível de abstração e de precisão que permitam ao projetista avaliar rapidamente o sistema, sem ter que depender de lentos e complexos modelos baseados em ISS. Neste trabalho é definido um conjunto de construtores para modelagem de plataformas baseadas em processadores, com suporte para desenvolvimento de HdS e reusabilidade dos componentes, técnicas para estimativa estática de tempo simulado em ambiente nativo de simulação e suporte para plataformas multiprocessadas. Foram realizados experimentos com aplica- ções de entrada e saída intensiva, computação intensiva e multiprocessada, com ganho médio de desempenho da ordem de 1.000 vezes e precisão de estimativas com erro médio inferior a 3%, em comparação com uma plataforma de referência baseada em ISS._________________________________________________________________________________________ ABSTRACT: The amazing advances of computer systems technology enabled the rise of innovative devices, such as modern touch sensitive cell phones and tablets. To properly manage these various interfaces, it is required the use of the Hardwaredependent Software (HdS) that is responsible for these devices control and access. Besides this complex arrangement of components, to meet the growing demand for more integrated features, the multiprocessing paradigm has been adopted to increase the platforms performance. Due to the system design gap, both industry and academia have been researching for more efficient processes to build and simulate systems with this increasingly complexity. The premise of the state of art works is the development of high level of abstraction and precise models to enable the designer to quickly evaluate the system, without having to rely on slow and complex models based on instruction set simulators (ISS). This work defined a set of constructors for processor-based platforms modeling, supporting HdS development and components reusability, techniques for static simulation timing estimation in native environment and support for multiprocessor platforms. Experiments were carried out with input and output intensive, compute intensive and multiprocessed applications leading to an average performance speed up of about 1,000 times and average timing estimation accuracy of less than 3%, when compared with a reference platform based on ISS.

L'identification des systèmes dynamiques complexes reste une préoccupation lorsque les erreurs de prédictions contiennent des outliers d'innovation. Ils ont pour effet de détériorer le modèle estimé, si le critère d'estimation est mal choisi et mal adapté. Cela a pour conséquences de contaminer la distribution de ces erreurs, laquelle présente des queues épaisses et s'écarte de la distribution normale. Pour résoudre ce problème, il existe une classe d'estimateurs, dits robustes, moins sensibles aux outliers, qui traitent d'une manière plus « douce » la transition entre résidus de niveaux très différents. Les M-estimateurs de Huber font partie de cette classe. Ils sont associés à un mélange des normes L2 et L1, liés à un modèle de distribution gaussienne perturbée, dit gross error model. A partir de ce cadre formel, nous proposons dans cette thèse, un ensemble d'outils d'estimation et de validation de modèles paramétriques linéaires et pseudo-linéaires boîte-noires, avec extension de l'intervalle de bruit dans les petites valeurs de la constante d'accord de la norme de Huber. Nous présentons ainsi les propriétés de convergence du critère d'estimation et de l'estimateur robuste. Nous montrons que l'extension de l'intervalle de bruit réduit la sensibilité du biais de l'estimateur et améliore la robustesse aux points de levage. Pour un type de modèle pseudo-linéaire, il est présenté un nouveau contexte dit L-FTE, avec une nouvelle méthode de détermination de L, dans le but d'établir les linéarisations du gradient et du Hessien du critère d'estimation, ainsi que de la matrice de covariance asymptotique de l'estimateur. De ces relations, une version robuste du critère de validation FPE est établie et nous proposons un nouvel outil d'aide au choix de modèle estimé. Des expérimentations sur des processus simulés et réels sont présentées et analysées.L'identification des systèmes dynamiques complexes reste une préoccupation lorsque les erreurs de prédictions contiennent des outliers d'innovation. Ils ont pour effet de détériorer le modèle estimé, si le critère d'estimation est mal choisi et mal adapté. Cela a pour conséquences de contaminer la distribution de ces erreurs, laquelle présente des queues épaisses et s'écarte de la distribution normale. Pour résoudre ce problème, il existe une classe d'estimateurs, dits robustes, moins sensibles aux outliers, qui traitent d'une manière plus « douce » la transition entre résidus de niveaux très différents. Les M-estimateurs de Huber font partie de cette classe. Ils sont associés à un mélange des normes L2 et L1, liés à un modèle de distribution gaussienne perturbée, dit gross error model. A partir de ce cadre formel, nous proposons dans cette thèse, un ensemble d'outils d'estimation et de validation de modèles paramétriques linéaires et pseudo-linéaires boîte-noires, avec extension de l'intervalle de bruit dans les petites valeurs de la constante d'accord de la norme de Huber. Nous présentons ainsi les propriétés de convergence du critère d'estimation et de l'estimateur robuste. Nous montrons que l'extension de l'intervalle de bruit réduit la sensibilité du biais de l'estimateur et améliore la robustesse aux points de levage. Pour un type de modèle pseudo-linéaire, il est présenté un nouveau contexte dit L-FTE, avec une nouvelle méthode de détermination de L, dans le but d'établir les linéarisations du gradient et du Hessien du critère d'estimation, ainsi que de la matrice de covariance asymptotique de l'estimateur. De ces relations, une version robuste du critère de validation FPE est établie et nous proposons un nouvel outil d'aide au choix de modèle estimé. Des expérimentations sur des processus simulés et réels sont présentées et analysées. / Complex dynamic systems identification remains a concern when prediction errors contain innovation outliers. They have the effect to damage the estimated model if the estimation criterion is badly chosen and badly adapted. The consequence is the contamination of the distribution of these errors; this distribution presents heavy tails and deviates of the normal distribution. To solve this problem, there is a robust estimator's class, less sensitive to the outliers, which treat the transition between residuals of very different levels in a softer way. The Huber's M-estimators belong to this class. They are associated to a mixed L2 - L1 norm, related to a disturbed Gaussian distribution model, namely gross error model. From this formal context, in this thesis we propose a set of estimation and validation tools of black-box linear and pseudo-linear models, with extension of the noise interval to low values of the tuning constant in the Huber's norm. We present the convergence properties of the robust estimation criterion and the robust estimator. We show that the extension of the noise interval reduces the sensitivity of the bias of the estimator and improves the robustness to the leverage points. Moreover, for a pseudo-linear model structure, we present a new context, named L-FTE, with a new method to determine L, in order to linearize the gradient and the Hessien of estimation criterion and the asymptotic covariance matrix of the estimator. From these expressions, a robust version of the FPE validation criterion is established and we propose a new decisional tool for the estimated model choice. Experiments on simulated and real systems are presented and analyzed.

En France, en 2015 les motocyclistes représentent 43% des blessés graves victimes d'accidents de la circulation routière. Au même moment, même si les accidents de chocs de motocyclistes contre les dispositifs de retenue routiers ne représentent en moyenne que 10% des accidents de la circulation routière, les motocyclistes présentent un risque de décès 30 à 80 fois supérieur au risque de décès des usagers de véhicules impliqués dans le même type d'accidents.Pour renforcer la sécurité des motocyclistes, les dispositifs de retenue pour automobiles (dispositifs traditionnels) sont équipés à leur partie inférieure d'écran de protection motards. Les écrans motards ont pour but d'amortir de manière progressive les chocs des motocyclistes en les empêchant dans le même temps de passer à travers la partie inférieure des dispositifs de retenue pour automobiles, de percuter un poteau et d'être sévèrement blessés. Les écrans motards doivent subir des essais de chocs normatifs et répondre à certaines exigences afin de pouvoir être installés sur le bord des routes européennes et de garantir surtout la sécurité des motards. Cependant, il n'existe que des procédures normatives pour tester ces dispositifs, la procédure LIER dans le contexte Français et la procédure normative EN 1317-8 dans le contexte Européen. Afin d'évaluer ces deux procédures normatives et de proposer de nouvelles dispositions pouvant servir de procédure normative plus avancée sur le protocole d'essais d'évaluation de performances d'écrans motards, des simulations numériques ont été réalisées. Un modèle numérique complet de dispositif de retenue routier équipé d'écran motard en acier a été développé et corrélé sur un essai de choc réel sur un dispositif de même type. Une fois corrélé,le modèle a été utilisé afin d'évaluer l'influence des conditions d'essais et des caractéristiques mécaniques matériaux de l'écran sur les performances de l'écran motard. Enfin, une nouvelle démarche d'évaluation de performances d'écran de protection motard a été mise en place / In France, in 2015,motorcyclists represent 43% of seriously injured accident victims in road traffic. At the same time, even though motorcyclists impact crashes against the road restraint systems represent on average 10% of accidents in road traffic, motorcyclists present a risk of death from30 to 80 times upper than the risk of death for users of vehicles involved in the same type of accidents. To enhance the safety of motorcyclists, Vehicle Restraints Systems (VRS) arefitted to the lower part of restraint systems for motorcyclists. Motorcyclist’s Restraint Systems (MRS) are designed to absorb shocks gradually and to preventmotorcyclists to pass through the lower part of VRS, to hit a post and be severely injured. Before being installed on the roadsides, MRS have to be crash-tested according to standards in order to evaluate their safety and ensure motorcyclists safety. However, there are only normative procedures to testMRS, the LIER procedurein the French context and the procedure EN1317-8 in the European context. To assess both normative procedures and propose new provisions which can be used as normative procedure more advanced on the protocol of MRS performances evaluation tests, numerical simulations were performed. A numerical model of MRS was developed and correlated on one real impact test on other device of same type. Once correlated, the model was used to conduct a parametric study on the test conditions and thematerialsmechanical properties of the MRS. Finally, a new demarche of MRS performances evaluation was developed

Abstract This dissertation presents complete parameterizations for a three-dimensional (3-D) geometry-based stochastic radio channel model (GSCM) at 10 GHz based on measurement campaigns. The thesis is divided into the following main parts: radio channel measurements, the characterization of model parameters, and model validation. Experimental multiple-input multiple-output (MIMO) channel measurements carried out in two-story lobby and urban small cell scenarios are first described. The measurements were performed with a vector network analyzer and dual polarized virtual antenna arrays with a bandwidth over 500 MHz. The measurement data was post-processed using the ESPRIT algorithm and the post-processed data was verified using a semi-deterministic map-based model. The results showed a good match between estimated and modeled multipath components (MPCs). In addition, single-input single-output outdoor-to-indoor measurements were executed through a standard multi-pane glass window and concrete wall. A statistical analysis was carried out for defining full 3-D characterization of the propagation channel in both line-of-sight (LOS) and non-line-of-sight (NLOS) propagation conditions. The delay and angular dispersions of MPCs are smaller in comparison to lower frequency bands due to the higher attenuation of the delayed MPCs. Moreover, specular reflection is observed to be the more dominant propagation mechanism in comparison to diffuse scattering, leading to smaller cluster angle spreads in comparison to lower frequency bands. The penetration loss caused by a standard multi-pane glass window is on the same level as in the lower frequency bands, whereas the loss caused by the concrete wall is a few dBs higher than at lower frequency bands. Finally, the GSCM with determined parameters is validated. A MIMO channel was reconstructed by embedding 3-D radiation patterns of the antennas into the propagation path estimates. Equivalently the channel simulations were performed with a quasi deterministic radio channel generator (QuaDRiGa) using the defined parameters. The channel capacity, Demmel condition number, and relative condition numbers are used as the comparison metrics between reconstructed and modeled channels. The results show that the reconstructed MIMO channel matches the simulated MIMO channel well. / Tiivistelmä Tämä väitöskirja esittää parametroinnit kolmiulotteiselle geometriaan perustuvalle stokastiselle radiokanavamallille 10 GHz:n taajuusalueella perustuen mitattuun radiokanavaan. Väitöskirja koostuu kolmesta pääalueesta: radiokanavamittaukset, radiokanavamallin parametrien määrittäminen ja mallin validointi. Aluksi kuvataan kaksikerroksisessa aula ja kaupunkipiensolu ympäristöissä monilähetin monivastaanotin (MIMO) järjestelmällä tehdyt kanavamittaukset. Mittaukset tehtiin vektoripiirianalysaattorilla ja kaksoispolaroiduilla virtuaaliantenniryhmillä 500 MHz kaistanleveydellä. Mittausdata jälkikäsiteltiin käyttämällä ESPRIT-algoritmia ja jälkikäsitelty data varmennettiin osittain deterministisellä mittausympäristön karttaan pohjautuvalla radiokanavamallilla. Tulokset osoittivat hyvän yhteensopivuuden mitattujen ja mallinnettujen moniteiden välillä. Lisäksi toteuttiin yksi-lähetin yksi-vastaanotin mittaukset ulko-sisä etenemisympäristössä monikerroksisen lasin ja betoniseinän läpi. Tilastollinen analyysin avulla määritettiin täysi kolmiulotteinen kuvaus radioaallon etenemiskanavasta näköyhteys ja näköyhteydettömässä tilanteissa. Moniteiden suuremmista vaimennuksista johtuen viive ja kulmahajonnat ovat pienemmät verrattaessa matalempiin taajuuksiin. Peiliheijastus on diffuusisirontaa merkittävämpi radioaallon etenemismekanismi johtaen pienempiin klustereiden kulmahajeisiin matalempiin taajuuksiin verrattuna. Monikerroksisen lasin läpäisyvaimennus on samankaltainen kuin alemmilla taajuuksilla, kun sitä vastoin betoniseinän vaimennus on muutaman desibelin suurempi kuin alemmilla taajuuksilla. Lopulta geometriaan perustava stokastinen radiokanavamalli validoidaan määritellyillä parametreilla. MIMO kanava uudelleen rakennetaan lisäämällä kolmiulotteiset antennien säteilykuviot estimoituihin radioaallon etenemisteihin. Vastaavasti radiokanava simuloidaan näennäisesti deterministisellä radiokanavageneraattorilla (QuaDRiGa) käyttäen määriteltyjä mallin parametreja. Kanavakapasiteettia, Demmel ehtolukua ja suhteellista ehtolukua käytetään vertailumittareina uudelleen rakennetun ja simuloidun kanavan välillä. Tulosten perusteella uudelleen rakennettu MIMO kanava on yhteensopiva simuloidun radiokanavan kanssa.

Understanding species-habitat relationships for endangered species is critical for their conservation. However, many studies have limited value for conservation because they fail to account for habitat associations at multiple spatial scales, anthropogenic variables, and imperfect detection. We addressed these three limitations by developing models for an endangered wetland bird, Yuma Ridgway's rail (Rallus obsoletus yumanensis), that examined how the spatial scale of environmental variables, inclusion of anthropogenic disturbance variables, and accounting for imperfect detection in validation data influenced model performance. These models identified associations between environmental variables and occupancy. We used bird survey and spatial environmental data at 2473 locations throughout the species' U.S. range to create and validate occupancy models and produce predictive maps of occupancy. We compared habitat-based models at three spatial scales (100, 224, and 500 m radii buffers) with and without anthropogenic disturbance variables using validation data adjusted for imperfect detection and an unadjusted validation dataset that ignored imperfect detection. The inclusion of anthropogenic disturbance variables improved the performance of habitat models at all three spatial scales, and the 224-m-scale model performed best. All models exhibited greater predictive ability when imperfect detection was incorporated into validation data. Yuma Ridgway's rail occupancy was negatively associated with ephemeral and slow-moving riverine features and high-intensity anthropogenic development, and positively associated with emergent vegetation, agriculture, and low-intensity development. Our modeling approach accounts for common limitations in modeling species-habitat relationships and creating predictive maps of occupancy probability and, therefore, provides a useful framework for other species.

Role-based modeling has been investigated for over 35 years as a promising paradigm to model complex, dynamic systems. Although current software systems are characterized by increasing complexity and context-dependence, all this research had almost no influence on current software development practice, still being discussed in recent literature. One reason for this is the lack of a coherent, comprehensive, readily applicable notion of roles. Researchers focused either on relational roles or context-dependent roles rather then combining both natures. Currently, there is no role-based modeling language sufficiently incorporating both the relational and context-dependent nature of roles together with the various proposed constraints. Hence, this paper formalizes a full-fledged role-based modeling language supporting both natures. To show its sufficiency and adequacy, a real world example is employed.

Since the year 1977, role modeling has been continuously investigated as promising paradigm to model complex, dynamic systems. However, this research had almost no influence on the design of todays increasingly complex and context-sensitive software systems. The reason for that is twofold. First, most modeling languages focused either on the behavioral, relational or context-dependent nature of roles rather than combining them. Second, there is a lack of tool support for the design, validation, and generation of role-based software systems. In particular, there exists no graphical role modeling editor supporting the three natures as well as the various proposed constraints. To overcome this deficiency, we introduce the Full-fledged Role Modeling Editor (FRaMED), a graphical modeling editor embracing all natures of roles and modeling constraints featuring generators for a formal representation and source code of a rolebased programming language. To show its applicability for the development of role-based software systems, an example from the banking domain is employed.

During 2018, the Public Transport Administration (Trafikförvaltningen) in the Stockholm region spent approximately 2.2 billion SEK on new infrastructure investments related to the public transport system, many of which were based on their public transport models. The previously used method for validating these models has lacked scientific rigour, efficiency and a systematic approach, which has led to uncertainty in decision making. Furthermore, few scientific studies have been conducted to develop validation methodologies for large-scale models, such as public transport models. For these reasons, a scientific validation methodology for public transport models has been developed in this thesis. This validation methodology has been applied on the 2014 route assignment model used by Trafikförvaltningen, for the transport modes bus, commuter train and local tram. In the developed validation methodology, the selected validation metrics called MAPE, %RMSE and R^2 are used to compare link loads from a route assignment model with observed link loads from an Automatic Passenger Counting (APC) system. To obtain an overview of the performance of the route assignment model, eight different scenarios are set, based on whether the validation metrics meet acceptable thresholds or not. In the application of the developed validation methodology, the average link loads for the morning rush have been validated. To adjust the developed validation methodology to system-specific factors and to set acceptable metric thresholds, discussions with model practitioners have taken place. The validation has been performed on both lines and links, and for bus entire line number series have been validated as well. The validation results show that commuter train meets the set threshold values in a higher proportion than bus and local tram do. However, Trafikförvaltningen is recommended to further calibrate the route assignment model in order to achieve a better model performance. The developed validation methodology can be used for validation of public transport models, and can in combination with model calibration be used in an iterative process to fine-tune model parameters for optimising validation results. Finally, a number of recommendations are proposed for Trafikförvaltningen to increase the efficiency and quality of the validation process, such as synchronising model data with the observed data. / Under 2018 spenderade Trafikförvaltningen ungefär 2,2 miljarder kronor på nya infrastrukturinvesteringar för kollektivtrafiksystemet i Stockholm, varav många av dessa baserades på deras kollektivtrafikmodeller. Den tidigare metoden för att valideras dessa modeller har saknat gedigen vetenskaplig grund, effektivitet och ett systematiskt tillvägagångssätt, vilket lett till osäkerhet gällande investeringsbeslut. Dessutom har få vetenskapliga studier genomförts för att ta fram valideringsmetodologier för storskaliga modeller, såsom kollektivtrafikmodeller. Av dessa skäl har en vetenskaplig valideringsmetodologi för kollektivtrafikmodeller tagits fram i detta examensarbete. Denna valideringsmetodologi har tillämpats på Trafikförvaltningens 2014 års nätutläggningsmodell, för trafikslagen buss, pendeltåg och spårväg. I den framtagna valideringsmetodologin har de valda valideringsmåtten vid namn MAPE, %RMSE och R^2 använts för att jämföra länkbelastningar från en nätutläggningsmodell med observerade länkbelastningar från ett Automatisk Trafikanträkning-system (ATR). För att ge en översikt över modellens precision har åtta scenarios satts baserat på om valideringsmåtten godkänns eller inte enligt tröskelvärden. I tillämpningen av den framtagna valideringsmetodologin har de genomsnittliga länkbelastningarna för morgonens rusningstrafik validerats. För att justera den framtagna valideringsmetodologin efter systemspecifika faktorer och för att sätta godkända tröskelvärden för valideringsmåtten, har diskussioner med trafikanalytiker hållits. Valideringen har utförts både på linjer och länkar, och för buss har även hela linjeserier validerats. Valideringsresultaten för pendeltåg har en högre andel godkända mätningar än buss och spårväg. Trafikförvaltningen rekommenderas dock att kalibrera nätutläggningsmodellen ytterligare för att uppnå ett bättre resultat. Den framtagna valideringsmetodologin kan användas för valideringar av kollektivtrafikmodeller, och kan i kombination med modellkalibrering användas i en iterativ process för att finjustera modellparametrar och därmed optimera valideringsresultaten. Slutligen föreslås ett antal rekommendationer för Trafikförvaltningen för att öka effektiviteten och kvaliteten på valideringsprocessen, till exempel att synkronisera modelldata med observerad data.

Transcatheter aortic heart valve replacement (TAVR) is a procedure to replace a failing aortic valve and is becoming the new standard of care for patients that are not candidates for open-heart surgery [2]. However, this minimally invasive technique has shown to cause ischemic brain lesions, or “silent infarcts”, in 90% of TAVR patients, which can increase the patient’s risk for stroke by two to four times in future years [3]. Claret Medical Inc., a medical device company, has developed a cerebral protection system that filters and captures embolic debris released during endovascular procedures, such as TAVR. This thesis utilized CT scans from Claret Medical to create a physical construct of the aortic arch to experimentally validate a theoretical computer model through flow visualization. The hypothesis was that the empirical model can accurately mimic the fluid dynamic properties of the aortic arch in order validate an in silico model using the finite elements program COMSOL MultiPhysics® Modeling Software. The physical model was created from a patient CT scan of the aortic arch using additive manufacturing (3D printing) and polymer casting, resulting in the shape of the aortic arch within a transparent, silicone material. Fluid was pumped through the model to visualize and quantify the velocity of the fluid within the aortic arch. COMSOL MultiPhysics® was used to model the aortic arch and obtain velocity measurements, which were statistically compared to the velocity measurements from the physical model. There was no significant difference between the values of the physical model and the computer model, confirming the hypothesis. Overall, this study successfully used CT scans to create an anatomically accurate physical model that was validated by a computer model using a novel technique of flow visualization. As TAVR and similar procedures continue to develop, the need for experimental evaluation and visualization of devices will continue to grow, making this project relevant to many companies in the medical device industry.