Literatura académica sobre el tema "Real-time model order reduction"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros

Elija tipo de fuente:

Consulte las listas temáticas de artículos, libros, tesis, actas de conferencias y otras fuentes académicas sobre el tema "Real-time model order reduction".

Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.

También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.

Artículos de revistas sobre el tema "Real-time model order reduction"

1

SUZUKI, Katsuyuki, Masaru OKAYASU y Ryuta OKADA. "1803 Real Time Large Deformation Simulation using Model Order Reduction". Proceedings of The Computational Mechanics Conference 2013.26 (2013): _1803–1_—_1803–3_. http://dx.doi.org/10.1299/jsmecmd.2013.26._1803-1_.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Dams, Dennis, Rob Gerth, Bart Knaack y Ruurd Kuiper. "Partial-order Reduction Techniques for Real-time Model Checking". Formal Aspects of Computing 10, n.º 5-6 (26 de mayo de 1998): 469–82. http://dx.doi.org/10.1007/s001650050028.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Frank, Tobias, Henrik Zeipel, Mark Wielitzka, Steffen Bosselmann y Tobias Ortmaier. "Real-Time Prediction of Curing Processes using Model Order Reduction". IFAC-PapersOnLine 53, n.º 2 (2020): 11132–37. http://dx.doi.org/10.1016/j.ifacol.2020.12.273.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Far, Mehrnaz Farzam, Floran Martin, Anouar Belahcen, Paavo Rasilo y Hafiz Asad Ali Awan. "Real-Time Control of an IPMSM Using Model Order Reduction". IEEE Transactions on Industrial Electronics 68, n.º 3 (marzo de 2021): 2005–14. http://dx.doi.org/10.1109/tie.2020.2973901.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Nasika, Christina, Pedro Díez, Pierre Gerard, Thierry J. Massart y Sergio Zlotnik. "Towards real time assessment of earthfill dams via Model Order Reduction". Finite Elements in Analysis and Design 199 (febrero de 2022): 103666. http://dx.doi.org/10.1016/j.finel.2021.103666.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

González, David, Alberto Badías, Icíar Alfaro, Francisco Chinesta y Elías Cueto. "Model order reduction for real-time data assimilation through Extended Kalman Filters". Computer Methods in Applied Mechanics and Engineering 326 (noviembre de 2017): 679–93. http://dx.doi.org/10.1016/j.cma.2017.08.041.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Vettermann, J., S. Sauerzapf, A. Naumann, M. Beitelschmidt, R. Herzog, P. Benner y J. Saak. "MODEL ORDER REDUCTION METHODS FOR COUPLED MACHINE TOOL MODELS". MM Science Journal 2021, n.º 3 (30 de junio de 2021): 4652–59. http://dx.doi.org/10.17973/mmsj.2021_7_2021072.

Texto completo
Resumen
Thermal effects are the most dominant source for displacements in machine tools and thus work-piece inaccuracies during the manufacturing process. A promising strategy to meet the ever-increasing accuracy requirements is the use of predictive models for, e.g., parameter and design op-timizations or online correction of the thermally induced error at the tool center point (TCP) in the pro-duction process. However, these techniques require fast but precise simulations. The need for high model accuracy is in direct contrast to the desired real-time capabilities. Model order reduction (MOR) is an attractive tool to overcome this problem. A modeling toolchain, which is tailored for the effective construction of fast and accurate models is proposed and demonstrated, emphasizing the involved MOR step.
Los estilos APA, Harvard, Vancouver, ISO, etc.
8

Kiss, Kristóf Levente y Tamás Orosz. "Model Order Reduction Methods for Rotating Electrical Machines: A Review". Energies 17, n.º 20 (16 de octubre de 2024): 5145. http://dx.doi.org/10.3390/en17205145.

Texto completo
Resumen
Due to the rise of e-mobility applications, there is an increased demand to create more accurate control methods, which can reduce the loss in an e-drive system. The accurate modeling of the rotating machines needs to resolve a partial differential equation system that describes the thermal and mechanical behavior of the different parts in addition to the electromagnetic design. Due to these models’ limited resources and high computation demand, they cannot be used directly for real-time control. Model order reduction methods have been of growing interest in the past decades and offer solutions for this problem. According to the processed literature, many model order reduction-based methods are used for a wide range of problems. However, a paper has not been published that discusses a model order reduction-based real-time control model that is actually used in the industry. This paper aims to summarize and systematically review the model order reduction methods developed for rotating electrical machines in the last two decades and examine the possible usage of these methods for a real-time control problem.
Los estilos APA, Harvard, Vancouver, ISO, etc.
9

SUZUKI, Katsuyuki, Masayuki WADA y Masaru OKAYASU. "2304 Real Time Simulation of Dynamic Large Deformation Problem using Model Order Reduction". Proceedings of The Computational Mechanics Conference 2012.25 (2012): 571–73. http://dx.doi.org/10.1299/jsmecmd.2012.25.571.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
10

ALDHAHERI, RABAH W. "Model order reduction via real Schur-form decomposition". International Journal of Control 53, n.º 3 (marzo de 1991): 709–16. http://dx.doi.org/10.1080/00207179108953642.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
Más fuentes

Tesis sobre el tema "Real-time model order reduction"

1

Quaranta, Giacomo. "Efficient simulation tools for real-time monitoring and control using model order reduction and data-driven techniques". Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/667474.

Texto completo
Resumen
Numerical simulation, the use of computers to run a program which implements a mathematical model for a physical system, is an important part of today technological world. It is required in many scientific and engineering fields to study the behaviour of systems whose mathematical models are too complex to provide analytical solutions and it makes virtual evaluation of systems responses possible (virtual twins). This drastically reduces the number of experimental tests for accurate designs of the real system that the numerical model represents. However these virtual twins, based on classical methods which make use of a rich representations of the system (ex. finite element method), rarely allows real-time feedback, even when considering high performance computing, operating on powerful platforms. In these circumstances, the real-time performance required in some applications are compromised. Indeed the virtual twins are static, that is, they are used in the design of complex systems and their components, but they are not expected to accommodate or assimilate data so as to define dynamic data-driven application systems. Moreover significant deviations between the observed response and the one predicted by the model are usually noticed due to inaccuracy in the employed models, in the determination of the model parameters or in their time evolution. In this thesis we propose different methods to solve these handicaps in order to perform real-time monitoring and control. In the first part Model Order Reduction (MOR) techniques are used to accommodate real-time constraints; they compute a good approximation of the solution by simplifying the solution procedure instead of the model. The accuracy of the predicted solution is not compromised and efficient simulations can be performed (digital twins). In the second part Data-Driven modelling are employed to fill the gap between the parametric solution computed by using non-intrusive MOR techniques and the measured fields, in order to make dynamic data-driven application systems, DDDAS, possible (Hybrid Twins).
La simulación numérica, el uso de ordenadores para ejecutar un programa que implementa un modelo matemático de un sistema físico, es una parte importante del mundo tecnológico actual. En muchos campos de la ciencia y la ingeniería es necesario estudiar el comportamiento de sistemas cuyos modelos matemáticos son demasiado complejos para proporcionar soluciones analíticas, haciendo posible la evaluación virtual de las respuestas de los sistemas (gemelos virtuales). Esto reduce drásticamente el número de pruebas experimentales para los diseños precisos del sistema real que el modelo numérico representa. Sin embargo, estos gemelos virtuales, basados en métodos clásicos que hacen uso de una rica representación del sistema (por ejemplo, el método de elementos finitos), rara vez permiten la retroalimentación en tiempo real, incluso cuando se considera la computación en plataformas de alto rendimiento. En estas circunstancias, el rendimiento en tiempo real requerido en algunas aplicaciones se ve comprometido. En efecto, los gemelos virtuales son estáticos, es decir, se utilizan en el diseño de sistemas complejos y sus componentes, pero no se espera que acomoden o asimilen los datos para definir sistemas de aplicación dinámicos basados en datos. Además, se suelen apreciar desviaciones significativas entre la respuesta observada y la predicha por el modelo, debido a inexactitudes en los modelos empleados, en la determinación de los parámetros del modelo o en su evolución temporal. En esta tesis se proponen diferentes métodos para resolver estas limitaciones con el fin de realizar un seguimiento y un control en tiempo real. En la primera parte se utilizan técnicas de Reducción de Modelos para satisfacer las restricciones en tiempo real; estas técnicas calculan una buena aproximación de la solución simplificando el procedimiento de resolución en lugar del modelo. La precisión de la solución no se ve comprometida y se pueden realizar simulaciones efficientes (gemelos digitales). En la segunda parte se emplea la modelización basada en datos para llenar el vacío entre la solución paramétrica, calculada utilizando técnicas de reducción de modelos no intrusivas, y los campos medidos, con el fin de hacer posibles los sistemas de aplicación dinámicos basados en datos (gemelos híbridos).
La simulation numérique, c'est-à-dire l'utilisation des ordinateurs pour exécuter un programme qui met en oeuvre un modèle mathématique d'un système physique, est une partie importante du monde technologique actuel. Elle est nécessaire dans de nombreux domaines scientifiques et techniques pour étudier le comportement de systèmes dont les modèles mathématiques sont trop complexes pour fournir des solutions analytiques et elle rend possible l'évaluation virtuelle des réponses des systèmes (jumeaux virtuels). Cela réduit considérablement le nombre de tests expérimentaux nécessaires à la conception précise du système réel que le modèle numérique représente. Cependant, ces jumeaux virtuels, basés sur des méthodes classiques qui utilisent une représentation fine du système (ex. méthode des éléments finis), permettent rarement une rétroaction en temps réel, même dans un contexte de calcul haute performance, fonctionnant sur des plates-formes puissantes. Dans ces circonstances, les performances en temps réel requises dans certaines applications sont compromises. En effet, les jumeaux virtuels sont statiques, c'est-à-dire qu'ils sont utilisés dans la conception de systèmes complexes et de leurs composants, mais on ne s'attend pas à ce qu'ils prennent en compte ou assimilent des données afin de définir des systèmes d'application dynamiques pilotés par les données. De plus, des écarts significatifs entre la réponse observée et celle prévue par le modèle sont généralement constatés en raison de l'imprécision des modèles employés, de la détermination des paramètres du modèle ou de leur évolution dans le temps. Dans cette thèse, nous proposons di érentes méthodes pour résoudre ces handicaps afin d'effectuer une surveillance et un contrôle en temps réel. Dans la première partie, les techniques de Réduction de Modèles sont utilisées pour tenir compte des contraintes en temps réel ; elles calculent une bonne approximation de la solution en simplifiant la procédure de résolution plutôt que le modèle. La précision de la solution n'est pas compromise et des simulations e caces peuvent être réalisées (jumeaux numériquex). Dans la deuxième partie, la modélisation pilotée par les données est utilisée pour combler l'écart entre la solution paramétrique calculée, en utilisant des techniques de réduction de modèles non intrusives, et les champs mesurés, afin de rendre possibles des systèmes d'application dynamiques basés sur les données (jumeaux hybrides).
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Wang, Xiang y 王翔. "Model order reduction of time-delay systems with variational analysis". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46604236.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Herath, Narmada Kumari. "Model order reduction for stochastic models of biomolecular systems with time-scale separation". Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118083.

Texto completo
Resumen
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 177-183).
Biomolecular systems often involve reactions that take place on different time-scales, giving rise to 'slow' and 'fast' system variables. This property is widely used in the analysis of systems to obtain dynamical models with reduced dimensions. In deterministic systems, methods to obtain such reduced-order models are well defined by the singular perturbation or averaging techniques. However, model reduction of stochastic systems remains an ongoing area of research. In particular, existing model reduction methods for stochastic models of biomolecular systems lack rigorous error quantifications between the full and reduced dynamics. Furthermore, they only provide approximations for the slow variable dynamics, making the application of such methods to biomolecular systems difficult since the variables of interest are typically mixed (i.e., they encompass both fast and slow variables). In this thesis, we consider biomolecular systems modeled using the chemical Langevin equation (CLE) and the Linear Noise Approximation (LNA). Specifically, we consider biomolecular systems with linear propensity functions modeled by the CLE and systems with arbitrary propensity functions modeled by the LNA. For these systems, we obtain reduced-order models that approximate both the slow and fast variables under time-scale separation conditions. In particular, with suitable assumptions, we prove that the moments of the reduced-order models converge to those of the full systems as the time-scale separation becomes large. Our results further provide a rigorous justification for the accuracy of the stochastic total quasi-steady state approximation (tQSSA). We then consider two applications of these reduced-order models. In the first application, we analyze the trade-offs between modularity and signal noise in biomolecular networks. In the second application, we consider the application of the reduced-order LNA developed in this work to obtain reduced-order stochastic models for gene-regulatory networks.
by Narmada Kumari Herath.
Ph. D.
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Muhirwa, Luc N. [Verfasser]. "Model Order Reduction of Linear Time Delay Systrems / Luc N. Muhirwa". München : Verlag Dr. Hut, 2016. http://d-nb.info/1120763312/34.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Goury, Olivier. "Computational time savings in multiscale fracture mechanics using model order reduction". Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/70925/.

Texto completo
Resumen
Engineering problems are very often characterised by a large ratio between the scale of the structure and the scale at which the phenomena of interest need to be described. In fracture mechanics, the initiation and propagation of cracks is the result of localised microscopic phenomena. This local nature of fracture leads to large numerical models. Projection-based reduced order modelling is an increasingly popular technique for the fast solution of parametrised problems. However, traditional model order reduction methods are unable to reliably deal with either the initiation or the propagation of a crack or a local zone with high damage concentration. In this thesis, we look at the general problem of applying model order reduction to fracture/ damage mechanics, in the pursuit of rationalising the computational time involved in these kind of simulations. The �rst contribution of this thesis is the development of a reduced-order modelling for computational homogenisation, which is a general multiscale method used to take microscopic data into account when deriving an engineeringscale model. A speci�c strategy is used to reduce the cost of solving the representative element volume (RVE) boundary value problem traditionally formulated in this method. The second contribution was made by developing a partitioned reduced-order procedure for the case of parametrised nonlinear material deformations involving a local lack of correlation, which typically happens with fracture. The method allows to reduce the regions undergoing little non-linearities whilst computational work can be concentrated on regions of high non-linearity.
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Zhang, Zheng y 张政. "Passivity assessment and model order reduction for linear time-invariant descriptor systems in VLSI circuit simulation". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44909056.

Texto completo
Resumen
The Best MPhil Thesis in the Faculties of Dentistry, Engineering, Medicine and Science (University of Hong Kong), Li Ka Shing Prize,2009-2010
published_or_final_version
Electrical and Electronic Engineering
Master
Master of Philosophy
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Bhattacharyya, Mainak. "A model reduction approach in space and time for fatigue damage simulation". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLN019/document.

Texto completo
Resumen
L'objet de ce projet de recherche est de prédire la durée de vie d'éléments mécaniques qui sont soumis à des phénomènes de fatigue cyclique. L'idée est de développer un schéma numérique novateur pour prédire la rupture de structures sous de tels chargements. Le modèle est basé sur la mécanique des milieux continus qui introduit des variables internes pour décrire l'évolution de l'endommagement. Le défi repose dans le traitement des cycles de chargement pour la prédiction de la durée de vie, particulièrement pour la prédiction de la durée de vie résiduelle de structures existantes. Les approches traditionnelles de l'analyse de la fatigue sont basées sur des méthodes phénoménologiques utilisant des relations empiriques. De telles méthodes considèrent des approximations simplificatrices et sont incapables de prendre en compte aisément des géométries ou des charges complexes associées à des problèmes d'ingénierie réels. Une approche basée sur la description de l'évolution thermodynamique d'un milieu continu est donc utilisée pour modéliser le comportement en fatigue. Cela permet de considérer efficacement des problèmes d'ingénierie complexe et la détérioration des propriétés du matériau due à la fatigue peut être quantifiée à l'aide de variables internes. Cependant, cette approche peut être numériquement coûteuse et, par conséquent, des approches numériques sophistiquées doivent être utilisées.La stratégie numérique sur laquelle ce projet est basé est singulière par rapport aux schémas incrémentaux en temps usuellement utilisés pour résoudre des problèmes élasto-(visco)plastique avec endommagement dans le cadre de la mécanique des milieux continus. Cette stratégie numérique appelée méthode LATIN (Large Time Increment method) est une méthode non-incrémentale qui recherche la solution de manière itérative sur l'ensemble du domaine spacio-temporel. Une importante innovation de la méthode LATIN est d'incorporer une stratégie de réduction de modèle adaptative pour réduire de manière très importante le coût numérique. La Décomposition Propre Généralisée (PGD) est une stratégie de réduction de modèle a priori qui sépare les quantités d'intérêt spacio-temporelles en deux composantes indépendantes, l'une dépendant du temps, l'autre de l'espace, et estime itérativement les approximations de ces deux composantes. L'utilisation de l'approche LATIN-PGD a montré son efficacité depuis des années pour résoudre des problèmes élasto-(visco)plastiques. La première partie de ce projet vise à étendre cette approche aux modèles incorporant de l'endommagement.Bien que l'utilisation de la PGD réduise les coûts numériques, le gain n'est pas suffisant pour permettre de résoudre des problèmes considérant un grand nombre de cycles de chargement, le temps de calcul peut être très conséquent, rendant les simulations de problèmes de fatigue intraitables même en utilisant les techniques LATIN-PGD. Cette limite peut être dépassée en introduisant une approche multi-échelle en temps, qui prend en compte l'évolution rapide des quantités d'intérêt lors d'un cycle et leur évolution lente au cours de l'ensemble des cycles. Une description type « éléments finis » en temps est proposée, où l'ensemble du domaine temporel est discrétisé en éléments temporels, et seulement les cycles nodaux, qui forment les limites des éléments, sont calculés en utilisant la technique LATIN-PGD. Puis, des fonctions de forme classiques sont utilisées pour interpoler les quantités d'intérêt à l'intérieur des éléments temporels. Cette stratégie LATIN-PGD à deux échelles permet de réduire le coût numérique de manière significative, et peut être utilisée pour simuler l'évolution de l'endommagement dans une structure soumise à un chargement de fatigue comportant un très grand nombre de cycles
The motivation of the research project is to predict the life time of mechanical components that are subjected to cyclic fatigue phenomena. The idea herein is to develop an innovative numerical scheme to predict failure of structures under such loading. The model is based on classical continuum damage mechanics introducing internal variables which describe the damage evolution. The challenge lies in the treatment of large number of load cycles for the life time prediction, particularly the residual life time for existing structures.Traditional approaches for fatigue analysis are based on phenomenological methods and deal with the usage of empirical relations. Such methods consider simplistic approximations and are unable to take into account complex geometries, and complicated loadings which occur in real-life engineering problems. A thermodynamically consistent continuum-based approach is therefore used for modelling the fatigue behaviour. This allows to consider complicated geometries and loads quite efficiently and the deterioration of the material properties due to fatigue can be quantified using internal variables. However, this approach can be computationally expensive and hence sophisticated numerical frameworks should be used.The numerical strategy used in this project is different when compared to regular time incremental schemes used for solving elasto-(visco)plastic-damage problems in continuum framework. This numerical strategy is called Large Time Increment (LATIN) method, which is a non-incremental method and builds the solution iteratively for the complete space-time domain. An important feature of the LATIN method is to incorporate an on-the-fly model reduction strategy to reduce drastically the numerical cost. Proper generalised decomposition (PGD), being a priori a model reduction strategy, separates the quantities of interest with respect to space and time, and computes iteratively the spatial and temporal approximations. LATIN-PGD framework has been effectively used over the years to solve elasto-(visco)plastic problems. Herein, the first effort is to solve continuum damage problems using LATIN-PGD techniques. Although, usage of PGD reduces the numerical cost, the benefit is not enough to solve problems involving large number of load cycles and computational time can be severely high, making simulations of fatigue problems infeasible. This can be overcome by using a multi-time scale approach, that takes into account the rapid evolution of the quantities of interest within a load cycle and their slow evolution along the load cycles. A finite element like description with respect to time is proposed, where the whole time domain is discretised into time elements, and only the nodal cycles, which form the boundary of the time elements, are calculated using LATIN-PGD technique. Thereby, classical shape functions are used to interpolate within the time element. This two-scale LATIN-PGD strategy enables the reduction of the computational cost remarkably, and can be used to simulate damage evolution in a structure under fatigue loading for a very large number of cycles
Los estilos APA, Harvard, Vancouver, ISO, etc.
8

Espinoza-Cuadros, Anelit, Marcavillaca Miriam Criollo, Pablo Mendoza-Vargas y Jose Alvarez. "Production model for the reduction of order delivery time in a peruvian metalworking company based on the six sigma dmaic methodology". Universidad Peruana de Ciencias Aplicadas (UPC), 2021. http://hdl.handle.net/10757/656015.

Texto completo
Resumen
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.
The present research work has as objective the application of Six Sigma DMAIC methodology in the production’s processes, the results will be manifested in increasing the efficiency of the production system and in reducing the delay in order delivery. In a metal mechanic company dedicated to the manufacture of electrical boards which focus is the terraced boards there was presented a fulfillment rate failure to deliver on time 46%. On the other hand, the delivery delay is generated because the current productivity does not supply what is required by the customer, therefore a minimum 394 units per month is needed to meet the requirements but currently only produce 226 units per month. For solve this problem it was proposed that Production model that merges the painting and baking areas and that generates an impact on the entire painting operation.
Los estilos APA, Harvard, Vancouver, ISO, etc.
9

Guillet, Jérôme. "Etude et réduction d'ordre de modèles linéraires structurés : application à la dynamique du véhicule". Phd thesis, Université de Haute Alsace - Mulhouse, 2011. http://tel.archives-ouvertes.fr/tel-00807199.

Texto completo
Resumen
Cette thèse traite de modélisation des systèmes complexes. Dans ce cadre, l'approche est basée sur les Modèles Structurés en Second Ordre (MSSO). Afin d'utiliser cette classe de modèles, les propriétés telles que l'atteignabilité, l'observabilité et les grammiens, bien connues pour les réalisations d'états, sont étendues aux MSSO.Lors de la co-simulation d'un système, des éléments de natures différentes (physiques et logicielles) sont intégrés et la simulation est effectuée en temps réel. Or, les modèles d'ordre élevés sont couteux en temps de calcul, ce qui rend difficile ce type de simulation. Ainsi, des méthodes de réduction de modèle sont explorées. En particulier, de nouvelles méthodes, permettant de préserver la structure des modèles avec une bonne erreur d'approximation sont présentées.Ces développements sont appliqués à la co-simulation de modèles véhicules sous forme de MSSO. Le modèle créé est un modèle par blocs, complexe et non-linéaire. Afin d'appliquer les méthodes de réduction de modèle il est nécessaire de le linéariser. La structure par blocs permet de linéariser l'ensemble du modèle ou de ne linéariser que certaines sous parties du modèle.Ensuite, l'identification des paramètres est effectuée pour chaque sous-systèmes du véhicule. Une méthode d'interconnexion est ensuite proposée pour créer une représentation monobloc du modèle afin de réduire ce dernier. Au final, des essais en co-simulation de la partie arrière du véhicule sous forme de modèle interconnectée avec la partie avant du véhicule physiquement présente sur un banc de test, valide notre approche pour effectuer de la co-simulation temps réel avec matériel.x
Los estilos APA, Harvard, Vancouver, ISO, etc.
10

Lauzeral, Nathan. "Reduced order and sparse representations for patient-specific modeling in computational surgery". Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0062.

Texto completo
Resumen
Cette thèse a pour but d’évaluer l'utilisation des méthodes de réduction de modèles fondées sur des approches parcimonieuses pour atteindre des performances en temps réel dans la cadre de la chirurgie computationnelle. Elle se concentre notamment sur l’intégration de la simulation biophysique dans des modèles personnalisés de tissus et d'organes afin d'augmenter les images médicales et ainsi éclairer le clinicien dans sa prise de décision. Dans ce contexte, trois enjeux fondamentaux sont mis en évidence. Le premier réside dans l'intégration de la paramétrisation de la forme au sein du modèle réduit afin de représenter fidèlement l'anatomie du patient. Une approche non intrusive reposant sur un échantillonnage parcimonieux de l'espace des caractéristiques anatomiques est introduite et validée. Ensuite, nous abordons le problème de la complétion des données et de la reconstruction des images à partir de données partielles ou incomplètes via des à priori physiques. Nous explorons le potentiel de la solution proposée dans le cadre du recalage d’images pour la réalité augmentée en laparoscopie. Des performances proches du temps réel sont obtenues grâce à une nouvelle approche d'hyper-réduction fondée sur une technique de représentation parcimonieuse. Enfin, le troisième défi concerne la propagation des incertitudes dans le cadre de systèmes biophysiques. Il est démontré que les approches de réduction de modèles traditionnelles ne réussissent pas toujours à produire une représentation de faible rang, et ce, en particulier dans le cas de la simulation électrochirurgicale. Une alternative est alors proposée via la métamodélisation. Pour ce faire, nous étendons avec succès l'utilisation de méthodes de régression parcimonieuses aux cas des systèmes à paramètres stochastiques
This thesis investigates the use of model order reduction methods based on sparsity-related techniques for the development of real-time biophysical modeling. In particular, it focuses on the embedding of interactive biophysical simulation into patient-specific models of tissues and organs to enhance medical images and assist the clinician in the process of informed decision making. In this context, three fundamental bottlenecks arise. The first lies in the embedding of the shape parametrization into the parametric reduced order model to faithfully represent the patient’s anatomy. A non-intrusive approach relying on a sparse sampling of the space of anatomical features is introduced and validated. Then, we tackle the problem of data completion and image reconstruction from partial or incomplete datasets based on physical priors. The proposed solution has the potential to perform scene registration in the context of augmented reality for laparoscopy. Quasi-real-time computations are reached by using a new hyperreduction approach based on a sparsity promoting technique. Finally, the third challenge concerns the representation of biophysical systems under uncertainty of the underlying parameters. It is shown that traditional model order reduction approaches are not always successful in producing a low dimensional representation of a model, in particular in the case of electrosurgery simulation. An alternative is proposed using a metamodeling approach. To this end, we successfully extend the use of sparse regression methods to the case of systems with stochastic parameters
Los estilos APA, Harvard, Vancouver, ISO, etc.
Más fuentes

Libros sobre el tema "Real-time model order reduction"

1

Lawford, Mark Stephen. Model reduction of discrete real-time systems. Ottawa: National Library of Canada = Bibliothèque nationale du Canada, 1997.

Buscar texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Bacior, Stanisław. Optymalizacja wiejskich układów gruntowych – badania eksperymentalne. Publishing House of the University of Agriculture in Krakow, 2019. http://dx.doi.org/10.15576/978-83-66602-37-3.

Texto completo
Resumen
Rural areas are subject to constant structural, spatial and economic transformations. The main purpose of this monograph was to present a new concept of shaping of rural land arrangement that takes into account the land value. The presented optimization methodology of shaping of the rural areas has a general range of application, not being limited by time or place. of the location of the consolidation object. The only condition for its use is the availability of a specific set of output data enabling the necessary calculations for the implementation of consolidation works. The described method has been successfully applied to the research object of the Mściowojów village, in a registry area located in the Dolnośląkie voivodeship, in the Jaworski district, providing with the assumed effects. In order to meet the research objectives, the shaping of rural land arrangement was conducted according to five models. The original arrangement of existing land division in a given village is considered as the 1st model. The 2nd model uses a rather accurate description of the locations of the lands in the village. To define this feature the location of farm parcels had to be determined. This model is the most accurate, but also the most labor-intensive of all. In the 3rd model, a fundamental simplification of the land arrangement was adopted, limiting the distance matrix to its measurement to the entry points from the settlements into the complexes. This simplification means that the location of parcels in the complex does not affect the average distance to the land in the whole village. On the basis of simplifications applied in the 3rd model allowing a significant reduction of the distance matrix the 4th model which uses a linear programming to minimize the distance to a parcel was developed. Introducing into the linear model an additional condition that eliminates distance growth in farms in relation to the initial state was important for the research. This was implemented in the 5th model and had a positive impact on the obtained results. The 6th model was developed by including the landowners' wants into the 5th model. These had to be taken into account so that the research/the new land arrangement did not cause complaints. The wants could not be fully included due to their inherently contradictory nature. The wants for having the parcel in a given arrangement was replaced with a guarantee of division, after which landowner receives no smaller share than the prior one. As demonstrated in the work, the solutions of the developed models allowed obtaining land arrangements close to the optimal in terms of distance to land and the shape of parcels and farms with regard to land specifics. The presented results allow to draw a conclusion that the methods and analyses applied in the research can have a wide range of application in shaping of rural land arrangement. Developing the most socially accepted optimization of parcel division in the process of land consolidation is important due to the actual needs for the implementation of the rural land arrangement research. This may also have influence on better use of the EU's financial resources for the consolidation of agricultural lands.
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Galderisi, Maurizio y Sergio Mondillo. Assessment of diastolic function. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199599639.003.0009.

Texto completo
Resumen
Modern assessment of left ventricular (LV) diastolic function should be based on the estimation of degree of LV filling pressure (LVFP), which is the true determinant of symptoms/signs and prognosis in heart failure.In order to achieve this goal, standard Doppler assessment of mitral inflow pattern (E/A ratio, deceleration time, isovolumic relaxation time) should be combined with additional manoeuvres and/or ultrasound tools such as: ◆ Valsalva manoeuvre applied to mitral inflow pattern. ◆ Pulmonary venous flow pattern. ◆ Velocity flow propagation by colour M-mode. ◆ Pulsed wave tissue Doppler of mitral annuls (average of septal and lateral E′ velocity).In intermediate doubtful situations, the two-dimensional determination of left atrial (LA) volume can be diagnostic, since LA enlargement is associated with a chronic increase of LVFP in the absence of mitral valve disease and atrial fibrillation.Some new echocardiographic technologies, such as the speckle tracking-derived LV longitudinal strain and LV torsion, LA strain, and even the three-dimensional determination of LA volumes can be potentially useful to add further information. In particular, the reduction of LV longitudinal strain in patients with LV diastolic dysfunction and normal ejection fraction demonstrates that a subclinical impairment of LV systolic function already exists under these circumstances.
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Queloz, Matthieu. The Practical Origins of Ideas. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198868705.001.0001.

Texto completo
Resumen
Why did such highly abstract ideas as truth, knowledge, or justice become so important to us? What was the point of coming to think in these terms? In The Practical Origins of Ideas, Matthieu Queloz presents a philosophical method designed to answer such questions: the method of pragmatic genealogy. Pragmatic genealogies are partly fictional, partly historical narratives exploring what might have driven us to develop certain ideas in order to discover what these do for us. The book uncovers an under-appreciated tradition of pragmatic genealogy which cuts across the analytic–continental divide, running from the state-of-nature stories of David Hume and the early genealogies of Friedrich Nietzsche to recent work in analytic philosophy by Edward Craig, Bernard Williams, and Miranda Fricker. However, these genealogies combine fictionalizing and historicizing in ways that even philosophers sympathetic to the use of state-of-nature fictions or real history have found puzzling. To make sense of why both fictionalizing and historicizing are called for, the book offers a systematic account of pragmatic genealogies as dynamic models serving to reverse-engineer the points of ideas in relation not only to near-universal human needs, but also to socio-historically situated needs. This allows the method to offer us explanation without reduction and to help us understand what led our ideas to shed the traces of their practical origins. Far from being normatively inert, moreover, pragmatic genealogy can affect the space of reasons, guiding attempts to improve our conceptual repertoire by helping us determine whether and when our ideas are worth having.
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

De Laurentis, Giacomo, Eugenio Alaio, Elisa Corsi, Emanuelemaria Giusti, Marco Guairo, Carlo Palego, Luca Paulicelli et al. Rischio di credito 2.0. AIFIRM, 2021. http://dx.doi.org/10.47473/2016ppa00030.

Texto completo
Resumen
The EBA Guidelines on loan origination and monitoring (hereinafter "GL LOM") undoubtedly represent a substantially new piece of the banking regulatory framework. In fact, for the first time, the regulator moves into a topic that was traditionally outside the scope of financial regulation, so far almost exclusively focused on aspects directly linked to both micro- and macro-prudential stability, notably through capital and liquidity management requirements and guidelines on Business Model and Internal Governance. The credit management process, and in particular loan origination and monitoring, has always been typically considered as a business issue under sole responsibility of banks, as it is considered one of the "core" processes (if not the "core" process) of the banking business. As a matter of fact, since the issue of the capital requirement regulation (i.e., Basel II and Basel III), and the introduction of the use requirements for the rating systems, the regulator moved very close, but not yet, to prescribe specific credit assessment criteria, while dictating methodological and organizational requirements for the authorization of the rating systems, and leaving substantial freedom to banks to define their own models and embedded assessment criteria and indicators. With the GL LOM, the regulator takes a further step, remarkably beyond its traditional remit, dictating principles and rules for the evaluation of the credit quality of borrowers. The starting point for this new approach from the regulator can be found in the ECB guidelines on Non-Performing Loans, later endorsed by the Bank of Italy Guidelines for Less Significant Banks, aimed at encouraging banks to define their NPL management processes and establish reduction plans to achieve NPL ratio targets in line with the regulator's expectations. Consistently with the focus on NPL, the regulation on Calendar Provisioning, amending the CRR was issued; as being a Regulation, it involves all banks, and not only significant ones (for which the ECB Addendum also applies). In addition, the new definition of default (the so-called "new Dod") has defined stricter criteria for the transition of exposures to the default status and also made the return of "cured" exposures to the performing status more difficult. The combined effect of these regulatory changes has been to make the default of counterparties not only more probable but also much more "expensive" for the banks. The natural “next step” of these regulatory changes was to "move backward" into the management process covering loan origination and monitoring . The EBA's stated objective with the issuance of the GL LOM is to define "robust and prudent" standards of lending practices so as to maintain a low level of NPLs in the future. Therefore, the focus of the GL LOM is the definition of requirements (some outlined as prescriptions, others in terms of principles) for the creditworthiness assessment of counterparties and for the management of the related data and information. Notwithstanding the fact that the Final Report has articulated the principle of proportionality much more clearly as compared to the Consultation Paper, the GLs set out three macro-categories of counterparties for which specific requirements are defined: • Individuals • Micro and small businesses • Medium and large companies. The GL LOM also provide recommendations about the valuation of guarantees both at origination and during ongoing monitoring, encouraging the use of advanced statistical models. The GL LOM focus on real estate guarantees, while financial collateral is outside the scope of the GL LOM. In the mind of the regulator, the GL LOM should not only reflect industry practices, but also incorporate the latest supervisory guidance on lending, and provide the stimulus to include ESG, AML/CTF and the use of innovative technologies into banking origination and, where applicable, monitoring processes.
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Sobczyk, Eugeniusz Jacek. Uciążliwość eksploatacji złóż węgla kamiennego wynikająca z warunków geologicznych i górniczych. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN, 2022. http://dx.doi.org/10.33223/onermin/0222.

Texto completo
Resumen
Hard coal mining is characterised by features that pose numerous challenges to its current operations and cause strategic and operational problems in planning its development. The most important of these include the high capital intensity of mining investment projects and the dynamically changing environment in which the sector operates, while the long-term role of the sector is dependent on factors originating at both national and international level. At the same time, the conditions for coal mining are deteriorating, the resources more readily available in active mines are being exhausted, mining depths are increasing, temperature levels in pits are rising, transport routes for staff and materials are getting longer, effective working time is decreasing, natural hazards are increasing, and seams with an increasing content of waste rock are being mined. The mining industry is currently in a very difficult situation, both in technical (mining) and economic terms. It cannot be ignored, however, that the difficult financial situation of Polish mining companies is largely exacerbated by their high operating costs. The cost of obtaining coal and its price are two key elements that determine the level of efficiency of Polish mines. This situation could be improved by streamlining the planning processes. This would involve striving for production planning that is as predictable as possible and, on the other hand, economically efficient. In this respect, it is helpful to plan the production from operating longwalls with full awareness of the complexity of geological and mining conditions and the resulting economic consequences. The constraints on increasing the efficiency of the mining process are due to the technical potential of the mining process, organisational factors and, above all, geological and mining conditions. The main objective of the monograph is to identify relations between geological and mining parameters and the level of longwall mining costs, and their daily output. In view of the above, it was assumed that it was possible to present the relationship between the costs of longwall mining and the daily coal output from a longwall as a function of onerous geological and mining factors. The monograph presents two models of onerous geological and mining conditions, including natural hazards, deposit (seam) parameters, mining (technical) parameters and environmental factors. The models were used to calculate two onerousness indicators, Wue and WUt, which synthetically define the level of impact of onerous geological and mining conditions on the mining process in relation to: —— operating costs at longwall faces – indicator WUe, —— daily longwall mining output – indicator WUt. In the next research step, the analysis of direct relationships of selected geological and mining factors with longwall costs and the mining output level was conducted. For this purpose, two statistical models were built for the following dependent variables: unit operating cost (Model 1) and daily longwall mining output (Model 2). The models served two additional sub-objectives: interpretation of the influence of independent variables on dependent variables and point forecasting. The models were also used for forecasting purposes. Statistical models were built on the basis of historical production results of selected seven Polish mines. On the basis of variability of geological and mining conditions at 120 longwalls, the influence of individual parameters on longwall mining between 2010 and 2019 was determined. The identified relationships made it possible to formulate numerical forecast of unit production cost and daily longwall mining output in relation to the level of expected onerousness. The projection period was assumed to be 2020–2030. On this basis, an opinion was formulated on the forecast of the expected unit production costs and the output of the 259 longwalls planned to be mined at these mines. A procedure scheme was developed using the following methods: 1) Analytic Hierarchy Process (AHP) – mathematical multi-criteria decision-making method, 2) comparative multivariate analysis, 3) regression analysis, 4) Monte Carlo simulation. The utilitarian purpose of the monograph is to provide the research community with the concept of building models that can be used to solve real decision-making problems during longwall planning in hard coal mines. The layout of the monograph, consisting of an introduction, eight main sections and a conclusion, follows the objectives set out above. Section One presents the methodology used to assess the impact of onerous geological and mining conditions on the mining process. Multi-Criteria Decision Analysis (MCDA) is reviewed and basic definitions used in the following part of the paper are introduced. The section includes a description of AHP which was used in the presented analysis. Individual factors resulting from natural hazards, from the geological structure of the deposit (seam), from limitations caused by technical requirements, from the impact of mining on the environment, which affect the mining process, are described exhaustively in Section Two. Sections Three and Four present the construction of two hierarchical models of geological and mining conditions onerousness: the first in the context of extraction costs and the second in relation to daily longwall mining. The procedure for valuing the importance of their components by a group of experts (pairwise comparison of criteria and sub-criteria on the basis of Saaty’s 9-point comparison scale) is presented. The AHP method is very sensitive to even small changes in the value of the comparison matrix. In order to determine the stability of the valuation of both onerousness models, a sensitivity analysis was carried out, which is described in detail in Section Five. Section Six is devoted to the issue of constructing aggregate indices, WUe and WUt, which synthetically measure the impact of onerous geological and mining conditions on the mining process in individual longwalls and allow for a linear ordering of longwalls according to increasing levels of onerousness. Section Seven opens the research part of the work, which analyses the results of the developed models and indicators in individual mines. A detailed analysis is presented of the assessment of the impact of onerous mining conditions on mining costs in selected seams of the analysed mines, and in the case of the impact of onerous mining on daily longwall mining output, the variability of this process in individual fields (lots) of the mines is characterised. Section Eight presents the regression equations for the dependence of the costs and level of extraction on the aggregated onerousness indicators, WUe and WUt. The regression models f(KJC_N) and f(W) developed in this way are used to forecast the unit mining costs and daily output of the designed longwalls in the context of diversified geological and mining conditions. The use of regression models is of great practical importance. It makes it possible to approximate unit costs and daily output for newly designed longwall workings. The use of this knowledge may significantly improve the quality of planning processes and the effectiveness of the mining process.
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Johansen, Bruce y Adebowale Akande, eds. Nationalism: Past as Prologue. Nova Science Publishers, Inc., 2021. http://dx.doi.org/10.52305/aief3847.

Texto completo
Resumen
Nationalism: Past as Prologue began as a single volume being compiled by Ad Akande, a scholar from South Africa, who proposed it to me as co-author about two years ago. The original idea was to examine how the damaging roots of nationalism have been corroding political systems around the world, and creating dangerous obstacles for necessary international cooperation. Since I (Bruce E. Johansen) has written profusely about climate change (global warming, a.k.a. infrared forcing), I suggested a concerted effort in that direction. This is a worldwide existential threat that affects every living thing on Earth. It often compounds upon itself, so delays in reducing emissions of fossil fuels are shortening the amount of time remaining to eliminate the use of fossil fuels to preserve a livable planet. Nationalism often impedes solutions to this problem (among many others), as nations place their singular needs above the common good. Our initial proposal got around, and abstracts on many subjects arrived. Within a few weeks, we had enough good material for a 100,000-word book. The book then fattened to two moderate volumes and then to four two very hefty tomes. We tried several different titles as good submissions swelled. We also discovered that our best contributors were experts in their fields, which ranged the world. We settled on three stand-alone books:” 1/ nationalism and racial justice. Our first volume grew as the growth of Black Lives Matter following the brutal killing of George Floyd ignited protests over police brutality and other issues during 2020, following the police assassination of Floyd in Minneapolis. It is estimated that more people took part in protests of police brutality during the summer of 2020 than any other series of marches in United States history. This includes upheavals during the 1960s over racial issues and against the war in Southeast Asia (notably Vietnam). We choose a volume on racism because it is one of nationalism’s main motive forces. This volume provides a worldwide array of work on nationalism’s growth in various countries, usually by authors residing in them, or in the United States with ethnic ties to the nation being examined, often recent immigrants to the United States from them. Our roster of contributors comprises a small United Nations of insightful, well-written research and commentary from Indonesia, New Zealand, Australia, China, India, South Africa, France, Portugal, Estonia, Hungary, Russia, Poland, Kazakhstan, Georgia, and the United States. Volume 2 (this one) describes and analyzes nationalism, by country, around the world, except for the United States; and 3/material directly related to President Donald Trump, and the United States. The first volume is under consideration at the Texas A & M University Press. The other two are under contract to Nova Science Publishers (which includes social sciences). These three volumes may be used individually or as a set. Environmental material is taken up in appropriate places in each of the three books. * * * * * What became the United States of America has been strongly nationalist since the English of present-day Massachusetts and Jamestown first hit North America’s eastern shores. The country propelled itself across North America with the self-serving ideology of “manifest destiny” for four centuries before Donald Trump came along. Anyone who believes that a Trumpian affection for deportation of “illegals” is a new thing ought to take a look at immigration and deportation statistics in Adam Goodman’s The Deportation Machine: America’s Long History of Deporting Immigrants (Princeton University Press, 2020). Between 1920 and 2018, the United States deported 56.3 million people, compared with 51.7 million who were granted legal immigration status during the same dates. Nearly nine of ten deportees were Mexican (Nolan, 2020, 83). This kind of nationalism, has become an assassin of democracy as well as an impediment to solving global problems. Paul Krugman wrote in the New York Times (2019:A-25): that “In their 2018 book, How Democracies Die, the political scientists Steven Levitsky and Daniel Ziblatt documented how this process has played out in many countries, from Vladimir Putin’s Russia, to Recep Erdogan’s Turkey, to Viktor Orban’s Hungary. Add to these India’s Narendra Modi, China’s Xi Jinping, and the United States’ Donald Trump, among others. Bit by bit, the guardrails of democracy have been torn down, as institutions meant to serve the public became tools of ruling parties and self-serving ideologies, weaponized to punish and intimidate opposition parties’ opponents. On paper, these countries are still democracies; in practice, they have become one-party regimes….And it’s happening here [the United States] as we speak. If you are not worried about the future of American democracy, you aren’t paying attention” (Krugmam, 2019, A-25). We are reminded continuously that the late Carl Sagan, one of our most insightful scientific public intellectuals, had an interesting theory about highly developed civilizations. Given the number of stars and planets that must exist in the vast reaches of the universe, he said, there must be other highly developed and organized forms of life. Distance may keep us from making physical contact, but Sagan said that another reason we may never be on speaking terms with another intelligent race is (judging from our own example) could be their penchant for destroying themselves in relatively short order after reaching technological complexity. This book’s chapters, introduction, and conclusion examine the worldwide rise of partisan nationalism and the damage it has wrought on the worldwide pursuit of solutions for issues requiring worldwide scope, such scientific co-operation public health and others, mixing analysis of both. We use both historical description and analysis. This analysis concludes with a description of why we must avoid the isolating nature of nationalism that isolates people and encourages separation if we are to deal with issues of world-wide concern, and to maintain a sustainable, survivable Earth, placing the dominant political movement of our time against the Earth’s existential crises. Our contributors, all experts in their fields, each have assumed responsibility for a country, or two if they are related. This work entwines themes of worldwide concern with the political growth of nationalism because leaders with such a worldview are disinclined to co-operate internationally at a time when nations must find ways to solve common problems, such as the climate crisis. Inability to cooperate at this stage may doom everyone, eventually, to an overheated, stormy future plagued by droughts and deluges portending shortages of food and other essential commodities, meanwhile destroying large coastal urban areas because of rising sea levels. Future historians may look back at our time and wonder why as well as how our world succumbed to isolating nationalism at a time when time was so short for cooperative intervention which is crucial for survival of a sustainable earth. Pride in language and culture is salubrious to individuals’ sense of history and identity. Excess nationalism that prevents international co-operation on harmful worldwide maladies is quite another. As Pope Francis has pointed out: For all of our connectivity due to expansion of social media, ability to communicate can breed contempt as well as mutual trust. “For all our hyper-connectivity,” said Francis, “We witnessed a fragmentation that made it more difficult to resolve problems that affect us all” (Horowitz, 2020, A-12). The pope’s encyclical, titled “Brothers All,” also said: “The forces of myopic, extremist, resentful, and aggressive nationalism are on the rise.” The pope’s document also advocates support for migrants, as well as resistance to nationalist and tribal populism. Francis broadened his critique to the role of market capitalism, as well as nationalism has failed the peoples of the world when they need co-operation and solidarity in the face of the world-wide corona virus pandemic. Humankind needs to unite into “a new sense of the human family [Fratelli Tutti, “Brothers All”], that rejects war at all costs” (Pope, 2020, 6-A). Our journey takes us first to Russia, with the able eye and honed expertise of Richard D. Anderson, Jr. who teaches as UCLA and publishes on the subject of his chapter: “Putin, Russian identity, and Russia’s conduct at home and abroad.” Readers should find Dr. Anderson’s analysis fascinating because Vladimir Putin, the singular leader of Russian foreign and domestic policy these days (and perhaps for the rest of his life, given how malleable Russia’s Constitution has become) may be a short man physically, but has high ambitions. One of these involves restoring the old Russian (and Soviet) empire, which would involve re-subjugating a number of nations that broke off as the old order dissolved about 30 years ago. President (shall we say czar?) Putin also has international ambitions, notably by destabilizing the United States, where election meddling has become a specialty. The sight of Putin and U.S. president Donald Trump, two very rich men (Putin $70-$200 billion; Trump $2.5 billion), nuzzling in friendship would probably set Thomas Jefferson and Vladimir Lenin spinning in their graves. The road of history can take some unanticipated twists and turns. Consider Poland, from which we have an expert native analysis in chapter 2, Bartosz Hlebowicz, who is a Polish anthropologist and journalist. His piece is titled “Lawless and Unjust: How to Quickly Make Your Own Country a Puppet State Run by a Group of Hoodlums – the Hopeless Case of Poland (2015–2020).” When I visited Poland to teach and lecture twice between 2006 and 2008, most people seemed to be walking on air induced by freedom to conduct their own affairs to an unusual degree for a state usually squeezed between nationalists in Germany and Russia. What did the Poles then do in a couple of decades? Read Hlebowicz’ chapter and decide. It certainly isn’t soft-bellied liberalism. In Chapter 3, with Bruce E. Johansen, we visit China’s western provinces, the lands of Tibet as well as the Uighurs and other Muslims in the Xinjiang region, who would most assuredly resent being characterized as being possessed by the Chinese of the Han to the east. As a student of Native American history, I had never before thought of the Tibetans and Uighurs as Native peoples struggling against the Independence-minded peoples of a land that is called an adjunct of China on most of our maps. The random act of sitting next to a young woman on an Air India flight out of Hyderabad, bound for New Delhi taught me that the Tibetans had something to share with the Lakota, the Iroquois, and hundreds of other Native American states and nations in North America. Active resistance to Chinese rule lasted into the mid-nineteenth century, and continues today in a subversive manner, even in song, as I learned in 2018 when I acted as a foreign adjudicator on a Ph.D. dissertation by a Tibetan student at the University of Madras (in what is now in a city called Chennai), in southwestern India on resistance in song during Tibet’s recent history. Tibet is one of very few places on Earth where a young dissident can get shot to death for singing a song that troubles China’s Quest for Lebensraum. The situation in Xinjiang region, where close to a million Muslims have been interned in “reeducation” camps surrounded with brick walls and barbed wire. They sing, too. Come with us and hear the music. Back to Europe now, in Chapter 4, to Portugal and Spain, we find a break in the general pattern of nationalism. Portugal has been more progressive governmentally than most. Spain varies from a liberal majority to military coups, a pattern which has been exported to Latin America. A situation such as this can make use of the term “populism” problematic, because general usage in our time usually ties the word into a right-wing connotative straightjacket. “Populism” can be used to describe progressive (left-wing) insurgencies as well. José Pinto, who is native to Portugal and also researches and writes in Spanish as well as English, in “Populism in Portugal and Spain: a Real Neighbourhood?” provides insight into these historical paradoxes. Hungary shares some historical inclinations with Poland (above). Both emerged from Soviet dominance in an air of developing freedom and multicultural diversity after the Berlin Wall fell and the Soviet Union collapsed. Then, gradually at first, right wing-forces began to tighten up, stripping structures supporting popular freedom, from the courts, mass media, and other institutions. In Chapter 5, Bernard Tamas, in “From Youth Movement to Right-Liberal Wing Authoritarianism: The Rise of Fidesz and the Decline of Hungarian Democracy” puts the renewed growth of political and social repression into a context of worldwide nationalism. Tamas, an associate professor of political science at Valdosta State University, has been a postdoctoral fellow at Harvard University and a Fulbright scholar at the Central European University in Budapest, Hungary. His books include From Dissident to Party Politics: The Struggle for Democracy in Post-Communist Hungary (2007). Bear in mind that not everyone shares Orbán’s vision of what will make this nation great, again. On graffiti-covered walls in Budapest, Runes (traditional Hungarian script) has been found that read “Orbán is a motherfucker” (Mikanowski, 2019, 58). Also in Europe, in Chapter 6, Professor Ronan Le Coadic, of the University of Rennes, Rennes, France, in “Is There a Revival of French Nationalism?” Stating this title in the form of a question is quite appropriate because France’s nationalistic shift has built and ebbed several times during the last few decades. For a time after 2000, it came close to assuming the role of a substantial minority, only to ebb after that. In 2017, the candidate of the National Front reached the second round of the French presidential election. This was the second time this nationalist party reached the second round of the presidential election in the history of the Fifth Republic. In 2002, however, Jean-Marie Le Pen had only obtained 17.79% of the votes, while fifteen years later his daughter, Marine Le Pen, almost doubled her father's record, reaching 33.90% of the votes cast. Moreover, in the 2019 European elections, re-named Rassemblement National obtained the largest number of votes of all French political formations and can therefore boast of being "the leading party in France.” The brutality of oppressive nationalism may be expressed in personal relationships, such as child abuse. While Indonesia and Aotearoa [the Maoris’ name for New Zealand] hold very different ranks in the United Nations Human Development Programme assessments, where Indonesia is classified as a medium development country and Aotearoa New Zealand as a very high development country. In Chapter 7, “Domestic Violence Against Women in Indonesia and Aotearoa New Zealand: Making Sense of Differences and Similarities” co-authors, in Chapter 8, Mandy Morgan and Dr. Elli N. Hayati, from New Zealand and Indonesia respectively, found that despite their socio-economic differences, one in three women in each country experience physical or sexual intimate partner violence over their lifetime. In this chapter ther authors aim to deepen understandings of domestic violence through discussion of the socio-economic and demographic characteristics of theit countries to address domestic violence alongside studies of women’s attitudes to gender norms and experiences of intimate partner violence. One of the most surprising and upsetting scholarly journeys that a North American student may take involves Adolf Hitler’s comments on oppression of American Indians and Blacks as he imagined the construction of the Nazi state, a genesis of nationalism that is all but unknown in the United States of America, traced in this volume (Chapter 8) by co-editor Johansen. Beginning in Mein Kampf, during the 1920s, Hitler explicitly used the westward expansion of the United States across North America as a model and justification for Nazi conquest and anticipated colonization by Germans of what the Nazis called the “wild East” – the Slavic nations of Poland, the Baltic states, Ukraine, and Russia, most of which were under control of the Soviet Union. The Volga River (in Russia) was styled by Hitler as the Germans’ Mississippi, and covered wagons were readied for the German “manifest destiny” of imprisoning, eradicating, and replacing peoples the Nazis deemed inferior, all with direct references to events in North America during the previous century. At the same time, with no sense of contradiction, the Nazis partook of a long-standing German romanticism of Native Americans. One of Goebbels’ less propitious schemes was to confer honorary Aryan status on Native American tribes, in the hope that they would rise up against their oppressors. U.S. racial attitudes were “evidence [to the Nazis] that America was evolving in the right direction, despite its specious rhetoric about equality.” Ming Xie, originally from Beijing, in the People’s Republic of China, in Chapter 9, “News Coverage and Public Perceptions of the Social Credit System in China,” writes that The State Council of China in 2014 announced “that a nationwide social credit system would be established” in China. “Under this system, individuals, private companies, social organizations, and governmental agencies are assigned a score which will be calculated based on their trustworthiness and daily actions such as transaction history, professional conduct, obedience to law, corruption, tax evasion, and academic plagiarism.” The “nationalism” in this case is that of the state over the individual. China has 1.4 billion people; this system takes their measure for the purpose of state control. Once fully operational, control will be more subtle. People who are subject to it, through modern technology (most often smart phones) will prompt many people to self-censor. Orwell, modernized, might write: “Your smart phone is watching you.” Ming Xie holds two Ph.Ds, one in Public Administration from University of Nebraska at Omaha and another in Cultural Anthropology from the Chinese Academy of Social Sciences, Beijing, where she also worked for more than 10 years at a national think tank in the same institution. While there she summarized news from non-Chinese sources for senior members of the Chinese Communist Party. Ming is presently an assistant professor at the Department of Political Science and Criminal Justice, West Texas A&M University. In Chapter 10, analyzing native peoples and nationhood, Barbara Alice Mann, Professor of Honours at the University of Toledo, in “Divide, et Impera: The Self-Genocide Game” details ways in which European-American invaders deprive the conquered of their sense of nationhood as part of a subjugation system that amounts to genocide, rubbing out their languages and cultures -- and ultimately forcing the native peoples to assimilate on their own, for survival in a culture that is foreign to them. Mann is one of Native American Studies’ most acute critics of conquests’ contradictions, and an author who retrieves Native history with a powerful sense of voice and purpose, having authored roughly a dozen books and numerous book chapters, among many other works, who has traveled around the world lecturing and publishing on many subjects. Nalanda Roy and S. Mae Pedron in Chapter 11, “Understanding the Face of Humanity: The Rohingya Genocide.” describe one of the largest forced migrations in the history of the human race, the removal of 700,000 to 800,000 Muslims from Buddhist Myanmar to Bangladesh, which itself is already one of the most crowded and impoverished nations on Earth. With about 150 million people packed into an area the size of Nebraska and Iowa (population less than a tenth that of Bangladesh, a country that is losing land steadily to rising sea levels and erosion of the Ganges river delta. The Rohingyas’ refugee camp has been squeezed onto a gigantic, eroding, muddy slope that contains nearly no vegetation. However, Bangladesh is majority Muslim, so while the Rohingya may starve, they won’t be shot to death by marauding armies. Both authors of this exquisite (and excruciating) account teach at Georgia Southern University in Savannah, Georgia, Roy as an associate professor of International Studies and Asian politics, and Pedron as a graduate student; Roy originally hails from very eastern India, close to both Myanmar and Bangladesh, so he has special insight into the context of one of the most brutal genocides of our time, or any other. This is our case describing the problems that nationalism has and will pose for the sustainability of the Earth as our little blue-and-green orb becomes more crowded over time. The old ways, in which national arguments often end in devastating wars, are obsolete, given that the Earth and all the people, plants, and other animals that it sustains are faced with the existential threat of a climate crisis that within two centuries, more or less, will flood large parts of coastal cities, and endanger many species of plants and animals. To survive, we must listen to the Earth, and observe her travails, because they are increasingly our own.
Los estilos APA, Harvard, Vancouver, ISO, etc.

Capítulos de libros sobre el tema "Real-time model order reduction"

1

Ge, Y., L. T. Watson, E. G. Collins y L. D. Davis. "Computationally Efficient Homotopies for the H 2 Model order Reduction Problem". En Linear Algebra for Large Scale and Real-Time Applications, 385–86. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8196-7_36.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Baumann, Michael, Dominik Hamann y Peter Eberhard. "Time-Dependent Parametric Model Order Reduction for Material Removal Simulations". En Model Reduction of Parametrized Systems, 491–504. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-58786-8_30.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Baur, Ulrike, Peter Benner, Bernard Haasdonk, Christian Himpe, Immanuel Martini y Mario Ohlberger. "Chapter 9: Comparison of Methods for Parametric Model Order Reduction of Time-Dependent Problems". En Model Reduction and Approximation, 377–407. Philadelphia, PA: Society for Industrial and Applied Mathematics, 2017. http://dx.doi.org/10.1137/1.9781611974829.ch9.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Naderi Lordejani, Sajad, Bart Besselink, Antoine Chaillet y Nathan van de Wouw. "On Extended Model Order Reduction for Linear Time Delay Systems". En Model Reduction of Complex Dynamical Systems, 191–215. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-72983-7_9.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Kumar, Mahendra, Aman y Siyaram Yadav. "Model Order Reduction of Time Interval System: A Survey". En Advances in Intelligent Systems and Computing, 265–77. New Delhi: Springer India, 2014. http://dx.doi.org/10.1007/978-81-322-1768-8_25.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Aumann, Quirin, Peter Benner, Jens Saak y Julia Vettermann. "Model Order Reduction Strategies for the Computation of Compact Machine Tool Models". En Lecture Notes in Production Engineering, 132–45. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-34486-2_10.

Texto completo
Resumen
AbstractThe deviation of the tool center point (TCP) of a machine tool from its desired location needs to be assessed correctly to ensure an accurate and safe operation of the machine. A major source of TCP deviation are thermal loads, which are constantly changing during operation. Numerical simulation models help predicting these loads, but are typically large and expensive to solve. Especially in (real-time feedback) control settings, but also to ensure an efficient design phase of machine tools, it is inevitable to use compact reduced-order surrogate models which approximate the behavior of the original system but are much less computationally expensive to evaluate. Model order reduction (MOR) methods generate computationally efficient surrogates. Classic intrusive methods require explicit access to the assembled system matrices. However, commercial software packages, which are typically used for the design of machine tools, do not always allow an unrestricted access to the required matrices. Non-intrusive data-driven methods compute surrogates requiring only input and output data of a dynamical system and are therefore independent of the discretization method. We evaluate the performance of such data-driven approaches to compute cheap-to-evaluate surrogate models of machine tools and compare their efficacy to intrusive MOR strategies. A focus is put on modeling the machine tool via individual substructures, which can be reduced independently of each other.
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Bradde, Tommaso, Alessandro Zanco y Stefano Grivet-Talocia. "Data-Driven Model Order Reduction of Parameterized Dissipative Linear Time-Invariant Systems". En Scientific Computing in Electrical Engineering, 152–58. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-54517-7_17.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
8

Thiem, Xaver, Holger Rudolph, Robert Krahn, Steffen Ihlenfeldt, Christof Fetzer y Jens Müller. "Adaptive Thermal Model for Structure Model Based Correction". En Lecture Notes in Production Engineering, 67–82. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-34486-2_6.

Texto completo
Resumen
AbstractThis paper discusses structure model based correction of thermal induced errors at machine tools. Using a machine model evaluated in thermal real-time, the thermal induced errors at the tool center point (TCP) are calculated based on information gotten from the machine control (e.g., axes velocities, positions, and motor currents) and ambient temperature. The machine model describes the physical relationships and considers the structure and structural variability resulting in traverse movements of the feed axes – the so-called structure model. To create this, finite elements are used as thermal and thermo-elastic models, and model order reduction (MOR) techniques are used to enable the calculation of high-resolution models in thermal real-time. Subsequent parameter updates can improve the accuracy of the initial parameter set of thermal models. A systematic procedure developed for this purpose and its application to a demonstrator machine are presented. For the update, parameters are selected which can change over the operating time, e.g., due to wear. Temperature sensor positions are chosen, sensitive to changes in these parameters. Simulations with parameters varied in a plausible range are used to determine whether parameter optimizations are reasonable. The parameter optimization runs in a trusted execution environment (TEE) on a server in parallel to the calculation of the correction model on the machine control. The confidential input data of the model and the model itself have to be protected from unauthorized access. The efficient model calculation and parameter optimization in a secure server environment leads to an adaptive thermal model (digital twin).
Los estilos APA, Harvard, Vancouver, ISO, etc.
9

Michiels, Wim, Gijs Hilhorst, Goele Pipeleers y Jan Swevers. "Model Order Reduction for Time-Delay Systems, with Application to Fixed-Order $$\mathscr {H}_2$$ H 2 Optimal Controller Design". En Recent Results on Time-Delay Systems, 45–66. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-26369-4_3.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
10

Stanisławski, Rafał, Marek Rydel y Krzysztof J. Latawiec. "New Implementation of Discrete-Time Fractional-Order PI Controller by Use of Model Order Reduction Methods". En Advances in Intelligent Systems and Computing, 1199–209. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-50936-1_100.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.

Actas de conferencias sobre el tema "Real-time model order reduction"

1

Tang, Man y Zhi-Hua Xiao. "Model order reduction of linear time-varying systems via shifted Legendre polynomials". En 2024 43rd Chinese Control Conference (CCC), 1340–45. IEEE, 2024. http://dx.doi.org/10.23919/ccc63176.2024.10662255.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Melendez, Nander, Jack Cruz y Cesar Salas. "MAS4CHICKEN: Multi-Agent Systems based order service model for waiting time reduction at rotisserie chicken restaurants in Lima - Peru". En 2024 11th International Conference on Soft Computing & Machine Intelligence (ISCMI), 193–98. IEEE, 2024. https://doi.org/10.1109/iscmi63661.2024.10851627.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Lubkowski, Grzegorz, Radosław Piesiewicz y Werner John. "Time Domain Modeling of Interconnected Integrated Circuits Based on Black Box Approach and Model Order Reduction for Signal Integrity Applications". En 2004_Wroclaw, 1–6. IEEE, 2004. https://doi.org/10.23919/emc.2004.10844155.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

McGahan, Paul, Cedric Rouaud y Michael Booker. "A Comparison of Model Order Reduction Techniques for Real-Time Battery Thermal Modelling". En WCX SAE World Congress Experience. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2019. http://dx.doi.org/10.4271/2019-01-0503.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Nguyen, Ngoc-Hien, Karen Willcox y Boo Cheong Khoo. "Model Order Reduction for Stochastic Optimal Control". En ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/esda2012-82061.

Texto completo
Resumen
This work presents an approach to solve stochastic optimal control problems in the application of flow quality management in reservoir systems. These applications are challenging because they require real-time decision-making in the presence of uncertainties such as wind velocity. These uncertainties must be accounted for as stochastic variables in the mathematical model. In addition, computational costs and storage requirements increase rapidly due to the stochastic nature of the simulations and optimisation formulations. To overcome these challenges, an approach is developed that uses the combination of a reduced-order model and an adjoint-based method to compute the optimal solution rapidly. The system is modelled by a system of stochastic partial differential equations. The finite element method together with collocation in the stochastic space provide an approximate numerical solution—the “full model”, which cannot be solved in real-time. The proper orthogonal decomposition and Galerkin projection technique are applied to obtain a reduced-order model that approximates the full model. The conjugate-gradient method with Armijo line-search is then employed to find the solution of the optimal control problem under the uncertainty of input parameters. Numerical results show that the stochastic control yields solutions that are above the bound of the set solutions of the deterministic control. Applying the reduced model to the stochastic optimal control problem yields a speed-up in computational time by a factor of about 80 with acceptable accuracy in comparison with the full model. Application of the optimal control strategy shows the potential effectiveness of this computational modeling approach for managing flow quality.
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Kahng, Sungtek y Raj Mittra. "Equivalent circuit model order reduction by real-coefficient AFS". En 2011 IEEE International Symposium on Electromagnetic Compatibility - EMC 2011. IEEE, 2011. http://dx.doi.org/10.1109/isemc.2011.6038439.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Gosea, Ion Victor, Igor Pontes Duff, Peter Benner y Athanasios C. Antoulas. "Model order reduction of bilinear time-delay systems". En 2019 18th European Control Conference (ECC). IEEE, 2019. http://dx.doi.org/10.23919/ecc.2019.8796085.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
8

Gupta, Shivam, Somica Pathak, Saurabh Singh, Satyam Singh y Ujjwal Yadav. "Model Order Reduction of Linear Time Invarient System". En 2024 International Conference on Communication, Computer Sciences and Engineering (IC3SE). IEEE, 2024. http://dx.doi.org/10.1109/ic3se62002.2024.10593493.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
9

Gao, Baofeng y Lamei Shang. "Research on Real-time Simulation Method of Vascular Interventional Surgery Based on Model Order Reduction". En 2020 IEEE International Conference on Mechatronics and Automation (ICMA). IEEE, 2020. http://dx.doi.org/10.1109/icma49215.2020.9233617.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
10

Xuanzeng, Lihong Feng, Yangfeng Su, Wei Cai, D. Zhou y C. Chiang. "Time Domain Model Order Reduction by Wavelet Collocation Method". En 2006 Design, Automation and Test in Europe. IEEE, 2006. http://dx.doi.org/10.1109/date.2006.243963.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.

Informes sobre el tema "Real-time model order reduction"

1

Carlberg, Kevin Thomas, Martin Drohmann, Raymond S. Tuminaro, Paul T. Boggs, Jaideep Ray y Bart Gustaaf van Bloemen Waanders. Breaking Computational Barriers: Real-time Analysis and Optimization with Large-scale Nonlinear Models via Model Reduction. Office of Scientific and Technical Information (OSTI), octubre de 2014. http://dx.doi.org/10.2172/1323654.

Texto completo
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Gómez Loscos, Ana, Miguel Ángel González Simón y Matías José Pacce. Short-term real-time forecasting model for spanish GDP (Spain-STING): new specification and reassessment of its predictive power. Madrid: Banco de España, marzo de 2024. http://dx.doi.org/10.53479/36137.

Texto completo
Resumen
The predictive power of short-term forecasting models was impaired by the increased volatility observed in most economic indicators following the outbreak of COVID-19. This paper sets out a revision of the Spain-STING model (one of the tools used by the Banco de España for short-term forecasts of quarter-on-quarter GDP growth) with a view to improving its predictive power in the wake of the pandemic. In particular, the revision entails three main changes: (i) the correlation between the indicators included in the model and the estimated common component is now coincident for all of the indicators, rather than leading in the case of some of them; (ii) by using a stochastic process to model the variance in the estimated common component, such variance may now vary over time; (iii) the set of indicators has been revised in order to include only those that provide the most relevant information when it comes to predicting post-pandemic GDP growth. These modifications yield a substantial improvement in the predictive power of Spain-STING in the post-pandemic period, and maintain such predictive power for the pre-pandemic period.
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Velghe, Ineke, Bart Buffel, Veerle Vandeginste, Wim Thielemans y Frederik Desplentere. Modelling hydrolytic, thermal, and mechanical degradation of PLA during single-screw extrusion. Universidad de los Andes, diciembre de 2024. https://doi.org/10.51573/andes.pps39.ss.dbc.1.

Texto completo
Resumen
Since melt processing causes degradation of poly(lactic acid) or PLA, it is crucial to understand the effect of extrusion conditions on the molecular weight reduction. Kinetic models found in literature are promising tools to describe hydrolytic, thermal, and mechanical degradation during extrusion. In order to use these models, extrusion parameters (that are equipment dependent) should be translated into the four fundamental parameters that determine degradation: moisture content in PLA, residence time, shear stress history and temperature history. This work presents a methodology to use numerical simulations to translate extrusion parameters into fundamental parameters. The results show that numerical simulations can be used successfully to describe the extrusion process based on residence time, shear stress history, and temperature history.
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Zhang, Renduo y David Russo. Scale-dependency and spatial variability of soil hydraulic properties. United States Department of Agriculture, noviembre de 2004. http://dx.doi.org/10.32747/2004.7587220.bard.

Texto completo
Resumen
Water resources assessment and protection requires quantitative descriptions of field-scale water flow and contaminant transport through the subsurface, which, in turn, require reliable information about soil hydraulic properties. However, much is still unknown concerning hydraulic properties and flow behavior in heterogeneous soils. Especially, relationships of hydraulic properties changing with measured scales are poorly understood. Soil hydraulic properties are usually measured at a small scale and used for quantifying flow and transport in large scales, which causes misleading results. Therefore, determination of scale-dependent and spatial variability of soil hydraulic properties provides the essential information for quantifying water flow and chemical transport through the subsurface, which are the key processes for detection of potential agricultural/industrial contaminants, reduction of agricultural chemical movement, improvement of soil and water quality, and increase of agricultural productivity. The original research objectives of this project were: 1. to measure soil hydraulic properties at different locations and different scales at large fields; 2. to develop scale-dependent relationships of soil hydraulic properties; and 3. to determine spatial variability and heterogeneity of soil hydraulic properties as a function of measurement scales. The US investigators conducted field and lab experiments to measure soil hydraulic properties at different locations and different scales. Based on the field and lab experiments, a well-structured database of soil physical and hydraulic properties was developed. The database was used to study scale-dependency, spatial variability, and heterogeneity of soil hydraulic properties. An improved method was developed for calculating hydraulic properties based on infiltration data from the disc infiltrometer. Compared with the other methods, the proposed method provided more accurate and stable estimations of the hydraulic conductivity and macroscopic capillary length, using infiltration data collected atshort experiment periods. We also developed scale-dependent relationships of soil hydraulic properties using the fractal and geostatistical characterization. The research effort of the Israeli research team concentrates on tasks along the second objective. The main accomplishment of this effort is that we succeed to derive first-order, upscaled (block effective) conductivity tensor, K'ᵢⱼ, and time-dependent dispersion tensor, D'ᵢⱼ, i,j=1,2,3, for steady-state flow in three-dimensional, partially saturated, heterogeneous formations, for length-scales comparable with those of the formation heterogeneity. Numerical simulations designed to test the applicability of the upscaling methodology to more general situations involving complex, transient flow regimes originating from periodic rain/irrigation events and water uptake by plant roots suggested that even in this complicated case, the upscaling methodology essentially compensated for the loss of sub-grid-scale variations of the velocity field caused by coarse discretization of the flow domain. These results have significant implications with respect to the development of field-scale solute transport models capable of simulating complex real-world scenarios in the subsurface, and, in turn, are essential for the assessment of the threat posed by contamination from agricultural and/or industrial sources.
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Ianchovichina, Elena. GTAP-DD: A Model for Analyzing Trade Reforms in the Presence of Duty Drawbacks. GTAP Technical Paper, marzo de 2004. http://dx.doi.org/10.21642/gtap.tp21.

Texto completo
Resumen
Duty drawback schemes, which typically involve a combination of duty rebates and exemptions, are a feature of many countries' trade regimes. They are used in highly protected, developing economies as means of providing exporters with imported inputs at world prices, and thus increasing their competitiveness, while maintaining the protection on the rest of the economy. In China duty exemptions have been central to the process of trade reform and have led to a tremendous increase in processed exports utilizing imported materials. Despite the widespread use and importance of duty drawbacks, these "new trade liberalization" instruments have been given relatively little attention in empirical multilateral trade liberalization studies. This paper presents an empirical multi-region trade model GTAP-DD, an extension of GTAP, in which the effects of policy reform are differentiated based on the trade-orientation of the firms. Both GTAP and GTAP-DD are used to analyze the impact of China's WTO accession, which involves liberalization in China from 1997 to post-accession tariffs among a number of other liberalization measures. The analysis shows that failure to account of duty exemptions in the case of China's recent WTO accession will overstate the increase in : (a) China's trade flows by 40 percent, (b) China's welfare by 15 percent, and (c) exports of selected sectors by as much as 90 percent. The magnitude of the bias depends on the level of pre-intervention tariffs and the size of tariff cuts - the larger the initial distortions and tariff reductions, the larger the bias when duty drawbacks are ignored. The bias in GTAP's estimates of China's real GDP, trade flows and welfare changes due to WTO accession increases more three times when China's pre-intervention tariffs are raised from their 1997 levels to the much higher 1995 levels. These results suggest that trade liberalization studies focusing on economies in which protection is high, import concessions play an important role and planned tariff cuts are deep, must treat duty drawbacks explicitly in order to avoid serious errors in their estimates of sectoral, trade flows and welfare changes.
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Handa, Avtar K., Yuval Eshdat, Avichai Perl, Bruce A. Watkins, Doron Holland y David Levy. Enhancing Quality Attributes of Potato and Tomato by Modifying and Controlling their Oxidative Stress Outcome. United States Department of Agriculture, mayo de 2004. http://dx.doi.org/10.32747/2004.7586532.bard.

Texto completo
Resumen
General The final goal and overall objective of the current research has been to modify lipid hydroperoxidation in order to create desirable phenotypes in two important crops, potato and tomato, which normally are exposed to abiotic stress associated with such oxidation. The specific original objectives were: (i) the roles of lipoxygenase (LOX) and phospholipids hydroperoxide glutathione peroxidase (PHGPx) in regulating endogenous levels of lipid peroxidation in plant tissues; (ii) the effect of modified lipid peroxidation on fruit ripening, tuber quality, crop productivity and abiotic stress tolerance; (iii) the effect of simultaneous reduction of LOX and increase of PHGPx activities on fruit ripening and tuber quality; and (iv) the role of lipid peroxidation on expression of specific genes. We proposed to accomplish the research goal by genetic engineering of the metabolic activities of LOX and PHGPx using regulatable and tissue specific promoters, and study of the relationships between these two consecutive enzymes in the metabolism and catabolism of phospholipids hydroperoxides. USA Significant progress was made in accomplishing all objectives of proposed research. Due to inability to regenerate tomato plants after transforming with 35S-PHGPx chimeric gene construct, the role of low catalase induced oxidative stress instead of PHGPx was evaluated on agronomical performance of tomato plant and fruit quality attributes. Effects of polyamine, that protects DNA from oxidative stress, were also evaluated. The transgenic plants under expressing lipoxygenase (LOX-sup) were crossed with catalase antisense (CAT-anti) plants or polyamine over producing plants (SAM-over) and the lines homozygous for the two transgenes were selected. Agronomical performance of these line showed that low catalase induced oxidative stress negatively affected growth and development of tomato plants and resulted in a massive change in fruit gene expression. These effects of low catalase activity induced oxidative stress, including the massive shift in gene expression, were greatly overcome by the low lipoxygenase activity. Collectively results show that oxidative stress plays significant role in plant growth including the fruit growth. These results also for the first time indicated that a crosstalk between oxidative stress and lipoxygenase regulated processes determine the outcome during plant growth and development. Israel Regarding PHGPx, most of the study has concentrated on the first and the last specific objectives, since it became evident that plant transformation with this gene is not obvious. Following inability to achieve efficient transformation of potato and tomato using a variety of promoters, model plant systems (tobacco and potato cell cultures, tobacco calli and plantlets, and Arabidopsis) were used to establish the factors and to study the obstacles which prohibited the regeneration of plants carrying the genetic machinery for overproduction of PHGPx. Our results clearly demonstrate that while genetic transformation and over-expression of PHGPx occurs in pre-developmental tissue stage (cell culture, calli clusters) or in completed plant (Arabidopsis), it is likely that over-expression of this enzyme before tissue differentiation is leading to a halt of the regeneration process. To support this assumption, experiments, in which genetic engineering of a point-mutated PHGPx gene enable transformation and over-expression in plants of PhSPY modified in its catalytic site and thus inactive enzymatically, were successfully carried out. These combined results strongly suggest, that if in fact, like in animals and as we established in vitro, the plant PHGPx exhibits PH peroxidase activity, these peroxides are vital for the organisms developmental process.
Los estilos APA, Harvard, Vancouver, ISO, etc.
7

Rahmani, Mehran, Xintong Ji y Sovann Reach Kiet. Damage Detection and Damage Localization in Bridges with Low-Density Instrumentations Using the Wave-Method: Application to a Shake-Table Tested Bridge. Mineta Transportation Institute, septiembre de 2022. http://dx.doi.org/10.31979/mti.2022.2033.

Texto completo
Resumen
This study presents a major development to the wave method, a methodology used for structural identification and monitoring. The research team tested the method for use in structural damage detection and damage localization in bridges, the latter being a challenging task. The main goal was to assess capability of the improved method by applying it to a shake-table-tested prototype bridge with sparse instrumentation. The bridge was a 4-span reinforced concrete structure comprising two columns at each bent (6 columns total) and a flat slab. It was tested to failure using seven biaxial excitations at its base. Availability of a robust and verified method, which can work with sparse recording stations, can be valuable for detecting damage in bridges soon after an earthquake. The proposed method in this study includes estimating the shear (cS) and the longitudinal (cL) wave velocities by fitting an equivalent uniform Timoshenko beam model in impulse response functions of the recorded acceleration response. The identification algorithm is enhanced by adding the model’s damping ratio to the unknown parameters, as well as performing the identification for a range of initial values to avoid early convergence to a local minimum. Finally, the research team detect damage in the bridge columns by monitoring trends in the identified shear wave velocities from one damaging event to another. A comprehensive comparison between the reductions in shear wave velocities and the actual observed damages in the bridge columns is presented. The results revealed that the reduction of cS is generally consistent with the observed distribution and severity of damage during each biaxial motion. At bents 1 and 3, cS is consistently reduced with the progression of damage. The trends correctly detected the onset of damage at bent 1 during biaxial 3, and damage in bent 3 during biaxial 4. The most significant reduction was caused by the last two biaxial motions in bents 1 and 3, also consistent with the surveyed damage. In bent 2 (middle bent), the reduction trend in cS was relatively minor, correctly showing minor damage at this bent. Based on these findings, the team concluded that the enhanced wave method presented in this study was capable of detecting damage in the bridge and identifying the location of the most severe damage. The proposed methodology is a fast and inexpensive tool for real-time or near real-time damage detection and localization in similar bridges, especially those with sparsely deployed accelerometers.
Los estilos APA, Harvard, Vancouver, ISO, etc.
8

Alchanatis, Victor, Stephen W. Searcy, Moshe Meron, W. Lee, G. Y. Li y A. Ben Porath. Prediction of Nitrogen Stress Using Reflectance Techniques. United States Department of Agriculture, noviembre de 2001. http://dx.doi.org/10.32747/2001.7580664.bard.

Texto completo
Resumen
Commercial agriculture has come under increasing pressure to reduce nitrogen fertilizer inputs in order to minimize potential nonpoint source pollution of ground and surface waters. This has resulted in increased interest in site specific fertilizer management. One way to solve pollution problems would be to determine crop nutrient needs in real time, using remote detection, and regulating fertilizer dispensed by an applicator. By detecting actual plant needs, only the additional nitrogen necessary to optimize production would be supplied. This research aimed to develop techniques for real time assessment of nitrogen status of corn using a mobile sensor with the potential to regulate nitrogen application based on data from that sensor. Specifically, the research first attempted to determine the system parameters necessary to optimize reflectance spectra of corn plants as a function of growth stage, chlorophyll and nitrogen status. In addition to that, an adaptable, multispectral sensor and the signal processing algorithm to provide real time, in-field assessment of corn nitrogen status was developed. Spectral characteristics of corn leaves reflectance were investigated in order to estimate the nitrogen status of the plants, using a commercial laboratory spectrometer. Statistical models relating leaf N and reflectance spectra were developed for both greenhouse and field plots. A basis was established for assessing nitrogen status using spectral reflectance from plant canopies. The combined effect of variety and N treatment was studied by measuring the reflectance of three varieties of different leaf characteristic color and five different N treatments. The variety effect on the reflectance at 552 nm was not significant (a = 0.01), while canonical discriminant analysis showed promising results for distinguishing different variety and N treatment, using spectral reflectance. Ambient illumination was found inappropriate for reliable, one-beam spectral reflectance measurement of the plants canopy due to the strong spectral lines of sunlight. Therefore, artificial light was consequently used. For in-field N status measurement, a dark chamber was constructed, to include the sensor, along with artificial illumination. Two different approaches were tested (i) use of spatially scattered artificial light, and (ii) use of collimated artificial light beam. It was found that the collimated beam along with a proper design of the sensor-beam geometry yielded the best results in terms of reducing the noise due to variable background, and maintaining the same distance from the sensor to the sample point of the canopy. A multispectral sensor assembly, based on a linear variable filter was designed, constructed and tested. The sensor assembly combined two sensors to cover the range of 400 to 1100 nm, a mounting frame, and a field data acquisition system. Using the mobile dark chamber and the developed sensor, as well as an off-the-shelf sensor, in- field nitrogen status of the plants canopy was measured. Statistical analysis of the acquired in-field data showed that the nitrogen status of the com leaves can be predicted with a SEP (Standard Error of Prediction) of 0.27%. The stage of maturity of the crop affected the relationship between the reflectance spectrum and the nitrogen status of the leaves. Specifically, the best prediction results were obtained when a separate model was used for each maturity stage. In-field assessment of the nitrogen status of corn leaves was successfully carried out by non contact measurement of the reflectance spectrum. This technology is now mature to be incorporated in field implements for on-line control of fertilizer application.
Los estilos APA, Harvard, Vancouver, ISO, etc.
9

Yang, Yu, Hen-Geul Yeh y Cesar Ortiz. Battery Management System Development for Electric Vehicles and Fast Charging Infrastructure Improvement. Mineta Transportation Institute, julio de 2024. http://dx.doi.org/10.31979/mti.2024.2325.

Texto completo
Resumen
The electric vehicle (EV) has become increasingly popular due to its being zero-emission. However, a significant challenge faced by EV drivers is the range anxiety associated with battery usage. Addressing this concern, this project develops a more efficient battery management system (BMS) for electric vehicles based on a real-time, state-of-charge (SOC) estimation. The proposed study delivers three modules: (1) a new equivalent circuit model (ECM) for lithium-ion batteries, (2) a new SOC estimator based on the moving horizon method, and (3) an on-board FPGA implementation of the classical Coulomb counting method for SOC estimation. The research team extends the traditional ECM by incorporating more functional features through the least absolute shrinkage and selection operator (LASSO). Then the first-order transfer function model identification and LASSO are iteratively executed to minimize the data fitting error. Given this model, the research team employs the moving horizon estimator (MHE) to determine the SOC by fitting the measured terminal voltage. Subsequently, the research team implements the SOC estimation scheme on an FPGA board. This hardware-in-the-loop simulation is demonstrated in this report step by step. The proposed research has broad societal impacts. It aligns with SB1 objectives in several ways. First, EVs with a more efficient BMS can improve their cruise range, reducing energy consumption and traffic congestion. Second, the resulting BMS can be applied in the solar-power and battery-assisted charging stations to make more reliable infrastructure in an age of sustainable transportation.
Los estilos APA, Harvard, Vancouver, ISO, etc.
10

Brydie, Dr James, Dr Alireza Jafari y Stephanie Trottier. PR-487-143727-R01 Modelling and Simulation of Subsurface Fluid Migration from Small Pipeline Leaks. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), mayo de 2017. http://dx.doi.org/10.55274/r0011025.

Texto completo
Resumen
The dispersion and migration behavior of hydrocarbon products leaking at low rates (i.e. 1bbl/day and 10 bbl/day) from a pipeline have been studied using a combination of experimental leakage tests and numerical simulations. The focus of this study was to determine the influence of subsurface engineered boundaries associated with the trench walls, and the presence of a water table, upon the leakage behavior of a range of hydrocarbon products. The project numerically modelled three products including diesel, diluted bitumen (dilbit) and gasoline; which were chosen to span a range of fluid types and viscosities. Laboratory simulations of leakage were carried out for the most viscous product (i.e. dilbit) in order to capture plume dispersion in semi-real time, and to allow numerical predictions to be assessed against experimental data. Direct comparisons between observed plume dimensions over time and numerically predicted behavior suggested a good match under low moisture conditions, providing confidence that the numerical simulation was sufficiently reliable to model field-scale applications. Following a simulated two year initialization period, the leakage of products, their associated gas phase migration, thermal and geomechanical effects were simulated for a period of 365 days. Comparisons between product leakage rate, product type and soil moisture content were made and the spatial impacts of leakage were summarized. Variably compacted backfill within the trench, surrounded by undisturbed and more compacted natural soils, results porosity and permeability differences which control the migration of liquids, gases, thermal effects and surface heave. Dilbit migration is influenced heavily by the trench, and also its increasing viscosity as it cools and degases after leakage. Diesel and gasoline liquid plumes are also affected by the trench structure, but to a lesser extent, resulting in wider and longer plumes in the subsurface. In all cases, the migration of liquids and gases is facilitated by higher permeability zones at the base of the pipe. Volatile Organic Compounds (VOCs) migrate along the trench and break through at the surface within days of the leak. Temperature changes within the trench may increase due liquid migration, however the change in predicted temperature at the surface above the leak is less than 0.5�C above background. For gasoline, the large amount of degassing and diffusion through the soil results in cooling of the soil by up to 1�C. Induced surface displacement was predicted for dilbit and for one case of diesel, but only in the order of 0.2cm above baseline. Based upon the information gathered, recommendations are provided for the use and placement of generic leak detection sensor types (e.g liquid, gas, thermal, displacement) within the trench and / or above the ground surface. The monitoring locations suggested take into account requirements to detect pipeline leakage as early as possible in order to facilitate notification of the operator and to predict the potential extent of site characterization required during spill response and longer term remediation activities.
Los estilos APA, Harvard, Vancouver, ISO, etc.
Ofrecemos descuentos en todos los planes premium para autores cuyas obras están incluidas en selecciones literarias temáticas. ¡Contáctenos para obtener un código promocional único!

Pasar a la bibliografía