Relevant bibliographies by topics / Nested-grid

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  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
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Academic literature on the topic 'Nested-grid'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Nested-grid"

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Harris, Lucas M., and Shian-Jiann Lin. "Global-to-Regional Nested Grid Climate Simulations in the GFDL High Resolution Atmospheric Model." Journal of Climate 27, no. 13 (July 2014): 4890–910. http://dx.doi.org/10.1175/jcli-d-13-00596.1.

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A two-way nested grid version of the Geophysical Fluid Dynamics Laboratory High Resolution Atmosphere Model (HiRAM) has been developed that uses simple methods for providing nested grid boundary conditions and mass-conserving nested-to-global communication. Nested grid simulations over the Maritime Continent and over North America were performed, each at two different resolutions: a 110-km mean grid cell width refined by a factor of 3, and a 50-km mean grid cell width refined by a factor of 2. Nested grid simulations were compared against uniform-resolution simulations, and against reanalyses, to determine the effect of grid nesting on both the modeled global climate and the simulation of small-scale features. Orographically forced precipitation was robustly found to be simulated with more detail and greater realism in a nested grid simulation compared with when only the coarse grids were simulated alone. Tropical precipitation biases were reduced in the Maritime Continent region when a nested grid was introduced. Both results were robust to changes in the nested grid parameterization tunings. In North America, cold-season orographic precipitation was improved by nesting, but precipitation biases in the central and eastern United States were little changed. Improving the resolution through nesting also allowed for more intense rainfall events, greater Kelvin wave activity, and stronger tropical cyclones. Nested grid boundary artifacts were more pronounced when a one-way, noninteractive nested grid was used.
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Harris, Lucas M., and Shian-Jiann Lin. "A Two-Way Nested Global-Regional Dynamical Core on the Cubed-Sphere Grid." Monthly Weather Review 141, no. 1 (January 1, 2013): 283–306. http://dx.doi.org/10.1175/mwr-d-11-00201.1.

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Abstract A nested-grid model is constructed using the Geophysical Fluid Dynamics Laboratory finite-volume dynamical core on the cubed sphere. The use of a global grid avoids the need for externally imposed lateral boundary conditions, and the use of the same governing equations and discretization on the global and regional domains prevents inconsistencies that may arise when these differ between grids. A simple interpolated nested-grid boundary condition is used, and two-way updates use a finite-volume averaging method. Mass conservation is achieved in two-way nesting by simply not updating the mass field. Despite the simplicity of the nesting methodology, the distortion of the large-scale flow by the nested grid is such that the increase in global error norms is a factor of 2 or less in shallow-water test cases. The effect of a nested grid in the tropics on the zonal means and eddy statistics of an idealized Held–Suarez climate integration is minor, and artifacts due to the nested grid are comparable to those at the edges of the cubed-sphere grid and decrease with increasing resolution. The baroclinic wave train in a Jablonowski–Williamson test case was preserved in a nested-grid simulation while finescale features were represented with greater detail in the nested-grid region. The authors also found that lee vortices could propagate out of the nested region and onto a coarse grid, which by itself could not produce vortices. Finally, the authors discuss how concurrent integration of the nested and coarse grids can be significantly more efficient than when integrating the two grids sequentially.
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D'Angelo, G., T. Henning, and W. Kley. "Nested-grid calculations of disk-planet interaction." Astronomy & Astrophysics 385, no. 2 (April 2002): 647–70. http://dx.doi.org/10.1051/0004-6361:20020173.

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Pleim, Jonathan E., Julius S. Chang, and Kesu Zhang. "A nested grid mesoscale atmospheric chemistry model." Journal of Geophysical Research 96, no. D2 (1991): 3065. http://dx.doi.org/10.1029/90jd02026.

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Xu, Zhiyu, Yonghua Tan, and Xiaoming Li. "Wavelet Methods and Adaptive Grids in One-Dimensional Movable Boundary Problems." Mathematical Problems in Engineering 2020 (March 9, 2020): 1–10. http://dx.doi.org/10.1155/2020/2545292.

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Adaptive wavelet collocation methods use wavelet transform and filtering to generate adaptive grids. However, if the boundary moves, the grid becomes aberrant. It baffles wavelet transform and makes the adaptive wavelet methods lose advantages on computational efficiency. This paper develops a series of methods or skills to effectively perform wavelet transform and to generate adaptive grids for one-dimensional movable boundary problems. The methods remain the original inner grid points and keep the grid in the original-nested structure, in order to remain scanty during the whole computing process. For boundary extending, the adaptive wavelet program begins to run on the very new grid beyond the original boundary once it reaches a nested structure, which is called the Intermittent Adaptive Method as a consequence. If the boundary extends tremendously, the new nested grids can be combined to a greater nested grid for further efficiency, which is named the Grid Combine Method. While for boundary contracting, a fictitious boundary is addressed to replace the original boundary that will recede, so wavelet transform can be successfully performed on the original nested grid. Finally, two numerical tests, local features moving and gas gun, were resolved and discussed to show the evolution process of the adaptive grids with the boundaries moving. For boundary contracting, the valid points decrease because the computation domain recedes; while for boundary extending, the valid point numbers vary between a range that almost remains unchanged.
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Mirocha, Jeffrey D., and Katherine A. Lundquist. "Assessment of Vertical Mesh Refinement in Concurrently Nested Large-Eddy Simulations Using the Weather Research and Forecasting Model." Monthly Weather Review 145, no. 8 (August 2017): 3025–48. http://dx.doi.org/10.1175/mwr-d-16-0347.1.

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To facilitate multiscale simulation using the Weather Research and Forecasting Model, vertical mesh refinement for one-way concurrent nested simulation was recently introduced. Grid refinement in the vertical dimension removes the requirement of different grid aspect ratios on the bounding versus the nested domain, such that results from refinement are in the horizontal directions only, and thereby can also reduce numerical errors on the bounding domain arising from large aspect ratios in the presence of complex terrain. Herein, the impacts of vertical grid refinement on the evolving downstream flow in nested large-eddy simulations are evaluated in relation to other model configuration choices, including turbulence subfilter-scale (SFS) stress models, mesh configuration, and alternative methods for calculating several near-surface flow parameters. Although vertical nesting requires coarsening of the vertical grid on the bounding domain, leading to a smaller range of resolved turbulence scales in the nest’s lateral boundary conditions, parameter values within the nested domains are generally only minimally impacted, relative to nesting using the same vertical grid on each domain. Two dynamic SFS models examined herein generally improved the simulated mean wind speed, turbulence kinetic energy, stresses and spectra, on both domains, and accelerated equilibration rates within nested domains, relative to two constant coefficient models. A new method of extrapolating horizontal velocity components to near-surface locations at nested domain lateral boundaries, and a correction to the calculation of deformation elements near the surface, are each shown to slightly alter the mean parameter values, yet only minimally impact equilibration rates within the nested domain.
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Zhang, Y., L. Jaeglé, A. van Donkelaar, R. V. Martin, C. D. Holmes, H. M. Amos, Q. Wang, et al. "Nested-grid simulation of mercury over North America." Atmospheric Chemistry and Physics 12, no. 14 (July 16, 2012): 6095–111. http://dx.doi.org/10.5194/acp-12-6095-2012.

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Abstract. We have developed a new nested-grid mercury (Hg) simulation over North America with a 1/2° latitude by 2/3° longitude horizontal resolution employing the GEOS-Chem global chemical transport model. Emissions, chemistry, deposition, and meteorology are self-consistent between the global and nested domains. Compared to the global model (4° latitude by 5° longitude), the nested model shows improved skill at capturing the high spatial and temporal variability of Hg wet deposition over North America observed by the Mercury Deposition Network (MDN) in 2008–2009. The nested simulation resolves features such as higher deposition due to orographic precipitation, land/ocean contrast and and predicts more efficient convective rain scavenging of Hg over the southeast United States. However, the nested model overestimates Hg wet deposition over the Ohio River Valley region (ORV) by 27%. We modify anthropogenic emission speciation profiles in the US EPA National Emission Inventory (NEI) to account for the rapid in-plume reduction of reactive to elemental Hg (IPR simulation). This leads to a decrease in the model bias to −2.3% over the ORV region. Over the contiguous US, the correlation coefficient (r) between MDN observations and our IPR simulation increases from 0.60 to 0.78. The IPR nested simulation generally reproduces the seasonal cycle in surface concentrations of speciated Hg from the Atmospheric Mercury Network (AMNet) and Canadian Atmospheric Mercury Network (CAMNet). In the IPR simulation, annual mean gaseous and particulate-bound Hg(II) are within 140% and 11% of observations, respectively. In contrast, the simulation with unmodified anthropogenic Hg speciation profiles overestimates these observations by factors of 4 and 2 for gaseous and particulate-bound Hg(II), respectively. The nested model shows improved skill at capturing the horizontal variability of Hg observed over California during the ARCTAS aircraft campaign. The nested model suggests that North American anthropogenic emissions account for 10–22% of Hg wet deposition flux over the US, depending on the anthropogenic emissions speciation profile assumed. The modeled percent contribution can be as high as 60% near large point sources in ORV. Our results indicate that the North American anthropogenic contribution to dry deposition is 13–20%.
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Zhang, Y., L. Jaeglé, A. van Donkelaar, R. V. Martin, C. D. Holmes, H. M. Amos, Q. Wang, et al. "Nested-grid simulation of mercury over North America." Atmospheric Chemistry and Physics Discussions 12, no. 1 (January 26, 2012): 2603–46. http://dx.doi.org/10.5194/acpd-12-2603-2012.

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Abstract. We have developed a new high-resolution (1/2° latitude by 2/3° longitude) nested-grid mercury (Hg) simulation over North America employing the GEOS-Chem global chemical transport model. Emissions, chemistry, deposition, and meteorology are self-consistent between the global and nested domains. Compared to the global model (4° latitude by 5° longitude), the nested model shows improved skill at capturing the high spatial and temporal variability of Hg wet deposition over North America observed by the Mercury Deposition Network (MDN) in 2008–2009. The nested simulation resolves features such as land/ocean contrast and higher deposition due to orographic precipitation, and predicts more efficient convective rain scavenging of Hg over the southeast United States. However, the nested model overestimates Hg wet deposition over the Ohio River Valley region (ORV) by 27%. We modify anthropogenic emission speciation profiles in the US EPA National Emission Inventory (NEI) to account for the rapid in-plume reduction of reactive to elemental Hg (IPR simulation). This leads to a decrease in the model bias to +3% over the ORV region. Over the contiguous US, the correlation coefficient (r) between MDN observations and our IPR simulation increases from 0.63 to 0.78. The IPR nested simulation generally reproduces the seasonal cycle in surface concentrations of speciated Hg from the Atmospheric Mercury Network (AMNet) and Canadian Atmospheric Mercury Network (CAMNet). In the IPR simulation, annual mean reactive gaseous and particulate-bound Hg are within 80% and 10% of observations, respectively. In contrast, the simulation with unmodified anthropogenic Hg speciation profiles overestimates these observations by factors of 2 to 4. The nested model shows improved skill at capturing the horizontal variability of Hg observed over California during the ARCTAS aircraft campaign. We find that North American anthropogenic emissions account for 10–22% of Hg wet deposition flux over the US, depending on the anthropogenic emissions speciation profile assumed. The percent contribution can be as high as 60% near large point emission sources in ORV. The contribution for the dry deposition is 13–20%.
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Wang, Qi Sheng, and Xue Ling Wang. "Convergence Analysis and the Nested Refinement for the Trapezoid Finite Element." Advanced Materials Research 317-319 (August 2011): 1921–25. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.1921.

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In this paper, a class of the new method of nested refinement based on self-adaption grid is discussed. The level trapezoid grid nested refinement on the plan domain and some related properties are investigated, and the convergence results are obtained for the second order self-adjoint elliptic problem on the trapezoid finite element.
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Ziegler, Udo, and Harold W. Yorke. "A nested grid refinement technique for magnetohydrodynamical flows." Computer Physics Communications 101, no. 1-2 (April 1997): 54–74. http://dx.doi.org/10.1016/s0010-4655(96)00163-4.

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Dissertations / Theses on the topic "Nested-grid"

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Colucci, Jay W. "A comparison of model performance between the nested grid and Eta models." Thesis, Monterey, California. Naval Postgraduate School, 1994. http://hdl.handle.net/10945/42792.

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This thesis examines the relationship between economic integration and immigration within the framework of complex interdependency and their impact on interstate relations. The hypothesis is that rising racial and ethnic tensions will result in a demand for increasingly restrictive immigration policies, which in turn can have an adverse effect on the economic integration process. The thesis compares two case studies: (1) the United States and Mexico within the context of NAFTA, and (2) Venezuela and Colombia within the context of the G-3 accord. In both case studies, concern over the economy and ability to absorb immigrant groups within the receiving countries (the United States and Venezuela) has created a demand for more restrictive immigration policies and tighter enforcement. Domestic considerations have traditionally prevailed in the unilateral formulation of immigration policy. However, with increased integration, immigration has begun to acquire increasing foreign policy implications. The persistence in following a unilateral immigration approach inconsistent with the economic integration process could strain interstate relations and hinder further integration. Although NAFTA and the G-3 accord have been in effect for less than one year, current events suggest that the incompatibility in policies, especially in the case of the United States and Mexico, has begun to affect bilateral relations. The thesis therefore recommends a bilateral approach to immigration policy, which will be more conducive to the process of economic integration.
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Solanka, Lukas. "Modelling microcircuits of grid cells and theta-nested gamma oscillations in the medial entorhinal cortex." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/10555.

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The relationship between structure, dynamics, and function of neural networks in nervous systems is still an open question in the neuroscience community. Nevertheless, for certain areas of the mammalian nervous system we do have sufficient data to impose constraints on the organisation of the network structure. One of these areas is the medial entorhinal cortex which contains cells with hexagonally repeating spatial receptive fields, called grid cells. Another intriguing property of entorhinal cortex and other cortical regions is a population oscillatory activity, with frequency in the theta (4-10 Hz) and gamma (30-100 Hz) range. This leads to a question, whether these oscillations are a common circuit mechanism that is functionally relevant and how the oscillatory activity interacts with the computation performed by grid cells. This thesis deals with applying the continuous attractor network theory to modelling of the microcircuit of layer II in the medial entorhinal cortex. Based on recent experimental evidence on connectivity between stellate cells, and fast spiking interneurons, I first develop a two-population spiking attractor network model that is capable of reproducing the activity of a population of grid cells in layer II. The network was implemented with exponential integrate and fire neurons that allowed me to address both the attractor states and the oscillatory activity in this region. Subsequently, I show that the network can produce theta-nested gamma oscillations with properties that are similar to the cross-frequency coupling observed in vivo and in vitro in entorhinal cortex, and that these theta-nested gamma oscillations can co-exist with grid-like receptive fields generated by the network. I also show that the connectivity inspired by anatomical evidence produces a number of directly testable predictions about the firing fields of interneurons in layer II of the medial entorhinal cortex. The excitatory-inhibitory attractor network, together with the theta-nested gamma oscillations, allowed me to explore potential relationships between nested gamma oscillations and grid field computations. I show, by varying the overall level of excitatory and inhibitory synaptic strengths, and levels of noise, in the network, that this relationship is complex, and not easily predictable. Specifically, I show that noise promotes generation of grid firing fields and theta-nested gamma oscillations by the model. I subsequently demonstrate that theta-nested gamma oscillations are dissociable from the grid field computations performed by the network. By changing the relative strengths of interactions between excitatory and inhibitory neurons in the network, the power and frequency of the gamma oscillations changes without disrupting the rate-coded grid field computations. Since grid cells have been suggested to be a part of the spatial cognitive circuit in the brain, these results have potential implications for several cognitive disorders, including autism and schizophrenia, as well as theories that propose a cognitive role for gamma oscillations.
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Hardy, Benjamin Arik. "A New Method for the Rapid Calculation of Finely-Gridded Reservoir Simulation Pressures." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd1123.pdf.

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Pointin, Fabien. "Etude spatiale des données collectées à bord des navires de pêche : en quoi est-elle pertinente pour la gestion des rejets de la pêche ?" Thesis, Rennes, Agrocampus Ouest, 2018. http://www.theses.fr/2018NSARH106/document.

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Depuis 2002, les pays membres de l’Union Européenne (UE) collectent, gèrent et fournissent des données nécessaires à la gestion des pêches et des rejets en particulier. Dans ce contexte, les programmes d’observation à la mer collectent des données à bord des navires de pêche sur la composition et la quantité des captures, y compris des rejets. En s’appuyant sur ces données, cette thèse a pour but d’analyser les variabilités spatio-temporelles des débarquements et des rejets de la pêche afin de contribuer à leur gestion. Pour cela, une méthode de cartographie basée sur des grilles à mailles variables a été développée. Cette méthode a été conçue pour produire des cartes pluriannuelles, annuelles et trimestrielles des débarquements et des rejets par espèce ou groupe selon le métier de pêche.Une plateforme basée sur des technologies Big Data a ensuite été utilisée avec pour objectifs d’affiner et d’automatiser la méthode de cartographie. Grâce à un système de stockage en ligne et un système d’analyse à haute performance, un grand nombre de cartes a ainsi pu être produit automatiquement par métier en regroupant ou non les années, les trimestres et les espèces. Finalement, l’utilité des cartes produites pour la gestion des rejets a été démontrée, en particulier dans le cadre de l’Obligation de Débarquement (Règlement (UE) n° 1380/2013). En s’appuyant sur des données de coûts et de revenus de flottilles, ces cartes permettent d’envisager des stratégies d’évitement de zones et/ou périodes de pêche propices aux captures non-désirées minimisant l’impact sur les performances économi
Since 2002, the European Union (EU) Members States collect, manage and supply data forthe management of fisheries and specifically of discards. In this context, at-sea observer programmes collect data on-board fishing vessels on the composition and quantity of catch, including discards. Based on these data, this study aims to analyse the spatio-temporal distribution of landings and discards so as to contribute to their management. In doing so, amapping method based on nested grids has been developed. This method has been designed to produce pluriannual, annual and quarterly maps of landings and discards per species or group of species according to the fishing metier.A platform based on Big Data technologies has then been used with the objectives of refining and automating the mapping method. Using an online storage system and a high-performance computing system, a large number of maps were produced automatically per métier, grouping or not years, quarters and species. Finally, the usefulness of the produced maps for managing discards has been demonstrated, particularly regarding the Landing Obligation (Regulation (UE) n° 1380/2013). Based on fleet cost and revenue data, these maps open up possibilities for identifying fishing zones and/or periods to be avoided (i.e., high bycatch) while minimising the impacts on fleet’s economic performances
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Altaie, Huda. "Nouvelle technique de grilles imbriquées pour les équations de Saint-Venant 2D." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4220/document.

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Les écoulements en eau peu profonde se rencontrent dans de nombreuses situations d’intérêts : écoulements de rivières et dans les lacs, mais aussi dans les mers et océans (courants de marée, tsunami, etc.). Ils sont modélisés par un système d’équations aux dérivées partielles, où les inconnues sont la vitesse de l’écoulement et la hauteur d’eau. On peut supposer que la composante verticale de la vitesse est petite devant les composantes horizontales et que ces dernières sont indépendantes de la profondeur. Le modèle est alors donné par les équations de shallow water (SWEs). Cette thèse se concentre sur la conception d’une nouvelle technique d’interaction de plusieurs grilles imbriquées pour modèle en eau peu profonde en utilisant des méthodes numériques. La première partie de cette thèse comprend, La dérivation complète de ces équations à partir des équations de Navier- Stokes est expliquée. Etudier le développement et l’évaluation des méthodes numériques en utilisant des méthodes de différences finies et plusieurs exemples numériques sont appliqués utilisant la condition initiale du niveau gaussien pour 2DSWEs. Dans la deuxième partie de la thèse, nous sommes intéressés à proposer une nouvelle technique d’interaction de plusieurs grilles imbriquées pour résoudre les modèles océaniques en utilisant quatre choix des opérateurs de restriction avec des résultats de haute précision. Notre travail s’est concentré sur la résolution numérique de SWE par grilles imbriquées. A chaque niveau de résolution, nous avons utilisé une méthode classique de différences finies sur une grille C d’Arakawa, avec un schéma de leapfrog complété par un filtre d’Asselin. Afin de pouvoir affiner les calculs dans les régions perturbées et de les alléger dans les zones calmes, nous avons considéré plusieurs niveaux de résolution en utilisant des grilles imbriquées. Ceci permet d’augmenter considérablement le rapport performance de la méthode, à condition de régler efficacement les interactions (spatiales et temporelles) entre les grilles. Dans la troisième partie de cette thèse, plusieurs exemples numéériques sont testés pour 2DSWE avec imbriqués 3:1 et 5:1. Finalement, la quatrième partie de ce travail, certaines applications de grilles imbriquées pour le modèle tsunami sont présentées
Most flows in the rivers, seas, and ocean are shallow water flow in which the horizontal length andvelocity scales are much larger than the vertical ones. The mathematical formulation of these flows, so called shallow water equations (SWEs). These equations are a system of hyperbolic partial differentialequations and they are effective for many physical phenomena in the oceans, coastal regions, riversand canals. This thesis focuses on the design of a new two-way interaction technique for multiple nested grids 2DSWEs using the numerical methods. The first part of this thesis includes, proposing several ways to develop the derivation of shallow water model. The complete derivation of this system from Navier-Stokes equations is explained. Studying the development and evaluation of numerical methods by suggesting new spatial and temporal discretization techniques in a standard C-grid using an explicit finite difference method in space and leapfrog with Robert-Asselin filter in time which are effective for modeling in oceanic and atmospheric flows. Several numerical examples for this model using Gaussian level initial condition are implemented in order to validate the efficiency of the proposed method. In the second part of our work, we are interested to propose a new two-way interaction technique for multiple nested grids to solve ocean models using four choices of higher restriction operators (update schemes) for the free surface elevation and velocities with high accuracy results. Our work focused on the numerical resolution of SWEs by nested grids. At each level of resolution, we used explicit finite differences methods on Arakawa C-grid. In order to be able to refine the calculations in troubled regions and move them into quiet areas, we have considered several levels of resolution using nested grids. This makes it possible to considerably increase the performance ratio of the method, provided that the interactions (spatial and temporal) between the grids are effectively controlled. In the third part of this thesis, several numerical examples are tested to show and verify twoway interaction technique for multiple nested grids of shallow water models can works efficiently over different periods of time with nesting 3:1 and 5:1 at multiple levels. Some examples for multiple nested grids of the tsunami model with nesting 5:1 using moving boundary conditions are tested in the fourth part of this work
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Ke-Wei and 詹可薇. "Nested Cartesian Grid Method in Incompressible and Viscous Fluid Flow." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/40404856933328484710.

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碩士
國立暨南國際大學
土木工程學系
97
In this paper, the local grid refinement is focused by using a nested grid technique. The nested Cartesian grid method is developed for simulating unsteady, viscous, incompressible flows with complex immersed boundaries. A finite volume method based on a second-order accurate central-difference scheme is used in conjunction with a two-step fractional-step procedure. The key aspects that need to be considered in developing such a nested grid solver are imposition of interface conditions on the nested-block boundaries and accurate discretization of the governing equation in cells that are with block-interface as a control surface. A new interpolation procedure is presented which allows systematic development of a spatial discretization scheme that preserves the spatial accuracy of the underlying solver. As a result, high efficiency and accuracy nested grid method is developed. The present nested grid method has been tested by four numerical examples to examine its performance in the two dimensional problems. The numerical examples include a lid-driven cavity flow problem, flow past a circular cylinder symmetrically installed in a Channel, flow past an ellipse with angle of attack, and flow past two circular cylinders with different diameters. For the numerical simulations of flow past bluff body problems, we used an Immersed Boundary (IB) method where the solid object is represented by a distributed body force in the Navier–Stokes equations. The main advantage of IB method is that the simulations can be performed on a regular Cartesian grid and thus applied with the present nested Cartesian grid method without difficulty. From the numerical experiments, the ability of the solver to simulate flows with complicated immersed boundaries is demonstrated and the nested grid approach can be efficiently combined with fractional-step algorithm to speed up the numerical solutions was also founded.
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Rubin, Evan Andrew. "Accuracy of the National Weather Service Nested Grid Model precipitation forecasts in the upper Midwest." 1988. http://catalog.hathitrust.org/api/volumes/oclc/19104566.html.

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Thesis (M.S.)--University of Wisconsin--Madison, 1988.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 114-116).
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Chen, Cheng Font, and 陳正豐. "Mapping Nested Loop Algorithms into Grid-Connected Systolic Arrays without Data Collisions in the Data Links." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/93759738839315705071.

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碩士
國立中正大學
電機工程研究所
81
Systolic arrays, which are made out of simple processing elements connected by data links,have made significient improvements in speeding up computation in comparision to conventional computers. Although systolic arrays belong to distributed memorey parallel devices, they adopt systolic communications instead of message passing communications for sending data between neighboring processing elements. Therefore, it is important to provide necessary and sufficient conditions to avoid data collisions in the data links for a correct algorithm design. In this paper, we present a complete set of necessary and sufficient conditions for mapping the class of shift-invarient uniform-dependence algorithms structured as nested loops into grid-connected systolic arrays of arbitrary dimensions. The proposed conditions, which are based on the ZERO-ONE-INFINITE property of tokens' behavior that describes how many times tokens are used and generated during the computation , can allow us to generate all feasible solutions.
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Shan, Shiliang. "Numerical Study of Three-dimensional Circulation and Hydrography in Halifax Harbour Using a Nested-grid Ocean Circulation Model." 2010. http://hdl.handle.net/10222/13173.

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Halifax Harbour is one of the world's largest natural harbours and has significant environmental and economic value. A good understanding of oceanographic processes is required for pollution control and sustainable development of the Harbour. A five-level nested-grid coastal ocean circulation model known as the Nested-grid Coastal Ocean Prediction System for Halifax Harbour (NCOPS-HFX) is used to reconstruct the three-dimensional circulation and hydrography and associated temporal and spatial variability of the Harbour. The NCOPS-HFX is driven by tides, meteorological forcing, and buoyancy forcing associated with river and sewage discharges. Model performances are assessed by comparing model results with available observations including sea level from tide gauges, CTD observations, current meter records and monthly mean climatology of temperature and salinity. Model results are also used to examine the main physical processes affecting circulation and hydrography in the Harbour. It is found that the near-surface currents in the Harbour are significantly affected by tides and wind forcing with an intense tidal jet in the Narrows and a salinity front in the upper layer of Bedford Basin. The time-mean circulation produced by the model is characterized by a typical two-layer estuarine circulation with seaward flow in the upper layer and landward flow in the lower layer. The model also reproduces reasonably well the seasonal changes of temperature and salinity in the Harbour. Dispersion and retention in the Harbour are studied based on numerical passive tracer and particle tracking experiments. The e-folding flushing time is about 40 and 90 days in the upper and entire Bedford Basin respectively, 2-5 days over the Inner and Outer Harbour, and about 1 day in the Narrows.
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Creasey, Robert L. "A comparison of horizontal and vertical velocities obtained from the flatland ST wind profiler and nested grid model analyses." 1991. http://catalog.hathitrust.org/api/volumes/oclc/24334337.html.

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Thesis (M.S.)--University of Wisconsin--Madison, 1991.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 68-70).
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Books on the topic "Nested-grid"

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Colucci, Jay W. A comparison of model performance between the nested grid and Eta models. Monterey, Calif: Naval Postgraduate School, 1994.

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2

Niewiadomski, M. The development of a long-range transport model with a nested fine resolution grid. [Toronto, Ont.]: Environment Ontario, 1991.

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Niewiadomski, M. The development of a long-range transport model with a nested fine resolution grid, phase II. [Toronto]: Ontario, Ministry of the Environment, 1993.

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4

Myrberg, Sara, and Tomas Riad. On the Expression of Focus in the Metrical Grid and in the Prosodic Hierarchy. Edited by Caroline Féry and Shinichiro Ishihara. Oxford University Press, 2015. http://dx.doi.org/10.1093/oxfordhb/9780199642670.013.41.

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This chapter examines the phonological correlates of information structural focus in the metrical grid and in the prosodic hierarchy, with emphasis on how they cooperate to express focus in simple cases but seem to conflict in more complex cases. Two Germanic languages, English and Swedish, are compared to highlight the implications of so-called nested foci and Second Occurrence Focus (SOF) with respect to how the metrical grid and the prosodic hierarchy interact in phonology. After providing an overview of metrical grid and prosodic hierarchy, a short description of Swedish intonation is given. The chapter then considers nested foci and SOF. It offers some predictions for Swedish of the constraint STRESSFOCUS, which does not specify what the correlation between metrical grid marks and heads of the prosodic hierarchy should be in the case of focus. It suggests that focus is expressed in a more categorical fashion in Swedish than in English.
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Book chapters on the topic "Nested-grid"

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Ouksel, M. Aris, and Otto Mayer. "The Nested Interpolation Based Grid File." In MFDBS 91, 173–87. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/3-540-54009-1_13.

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Kuwabara, Takuhito, Ryoji Matsumoto, Sigeki Miyaji, and Kenji Nakamura. "Implementation of Nested Grid Scheme for Global Magnetohydrodynamic Simulations of Astrophysical Rotating Plasmas." In High Performance Computing and Networking, 564–67. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/3-540-45492-6_63.

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Nga, Duong Thi Thuy, and Nguyen Ky Phung. "Applying Moving Boundary and Nested Grid to Compute the Accretion, Erosion at the Estuary." In Lecture Notes in Electrical Engineering, 1–10. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-28798-5_1.

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Zheng, Xudong, Rajat Mittal, and Yifan Peng. "A Hierarchical Nested Grid Approach for Local Refinement Coupled with an Immersed Boundary Method." In Computational Fluid Dynamics 2008, 461–66. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01273-0_59.

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Protonotariou, A. P., E. Bossioli, M. Tombrou, N. Mihalopoulos, G. Biskos, J. Kalogiros, G. Kouvarakis, and V. Amiridis. "Air Pollution in Eastern Mediterranean: Nested-Grid GEOS-CHEM Model Results and Airborne Observations." In Advances in Meteorology, Climatology and Atmospheric Physics, 1203–9. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-29172-2_168.

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Hackbusch, Wolfgang. "Nested Iteration Technique." In Multi-Grid Methods and Applications, 98–111. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-662-02427-0_5.

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Nolan, Matt. "A Model for Grid Firing and Theta-Nested Gamma Oscillations in Layer 2 of the Medial Entorhinal Cortex." In Springer Series in Computational Neuroscience, 567–84. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-99103-0_15.

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Goody, R. M., and Y. L. Yung. "Radiation Calculations in a Clear Atmosphere." In Atmospheric Radiation. Oxford University Press, 1989. http://dx.doi.org/10.1093/oso/9780195051346.003.0008.

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This chapter is concerned with the requirements of numerical weather prediction and general circulation models. These numerical models always assume a stratified atmosphere and utilize a limited number of grid points in the vertical direction. Computations are repeated at many horizontal grid points and at frequent time intervals; a premium is placed on computational economy. The nested integrals involved in radiative flux and heating calculations, particularly the frequency integration, can create an unacceptable computational burden unless approximated. In this chapter we limit attention to clear-sky conditions, i.e., to absorbing constituents and a thermal source function (§2.2). For a Planck function, the formal solution, (2.86), is a definite integral involving measurable quantities, temperatures, and gaseous densities. Scattering problems, on the other hand, involve the intensity in the source function and cannot be solved by a single application of this integral. Scattering calculations will be discussed further in Chapter 8; it will be shown that scattering can be neglected if the volume scattering coefficient is not very much larger than the volume absorption coefficient. This is usually the case for aerosols in the thermal region of the spectrum. As regards boundary conditions, it is usual for clear-sky calculations to assume that the earth’s surface and the upper and lower surfaces of clouds can be treated as black surfaces in the thermal spectrum. Equations (2.86) and (2.87) are stated in terms of general boundary conditions. In the flux and heating integrals, (2.106) and (2.110), these conditions are specialized to a black surface at ground level, but they can be generalized without difficulty to include a black surface at any level or partial reflection from these surfaces, if appropriate. The equations for which efficient algorithms are required are the flux equations, (2.107) and (2.108), the heating equations, (2.110) or (2.111), and the solar flux equations, (2.115). The nested integrals are 1. the vertical integral, (2.92), for the optical depth; 2. the integral, (2.86), along the optical path; 3. the angular integral, (2.102); 4. an integral over all frequencies. We may introduce the issues by considering a restricted example, that of the intensity recorded outside the atmosphere by a downward pointing satellite spectrometer.
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Elsner, James B., and Thomas H. Jagger. "Graphs and Maps." In Hurricane Climatology. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199827633.003.0008.

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Graphs and maps help you reason with data. They also help you communicate results. A good graph gives you the most information in the shortest time, with the least ink in the smallest space (Tufte, 1997). In this chapter, we show you how to make graphs and maps using R. A good strategy is to follow along with an open session, typing (or copying) the code as you read. Before you begin make sure you have the following data sets available in your workspace. Do this by typing . . . > SOI = read.table("SOI.txt", header=TRUE) > NAO = read.table("NAO.txt", header=TRUE) > SST = read.table("SST.txt", header=TRUE) > A = read.table("ATL.txt", header=TRUE) > US = read.table("H.txt", header=TRUE) . . . Not all the code is shown but all is available on our Web site. It is easy to make a graph. Here we provide guidance to help you make informative graphs. It is a tutorial on how to create publishable figures from your data. In R you have several choices. With the standard (base) graphics environment, you can produce a variety of plots with fine details. Most of the figures in this book use the standard graphics environment. The grid graphics environment is even more flexible. It allows you to design complex layouts with nested graphs where scaling is maintained upon resizing. The lattice and ggplot2 packages use grid graphics to create more specialized graphing functions and methods. The spplot function for example is plot method built with grid graphics that you will use to create maps. The ggplot2 package is an implementation of the grammar of graphics combining advantages from the standard and lattice graphic environments. It is worth the effort to learn. We begin with the standard graphics environment. A box plot is a graph of the five-number summary. The summary function applied to data produces the sample mean along with five other statistics including the minimum, the first quartile value, the median, the third quartile value, and the maximum. The box plot graphs these numbers. This is done using the boxplot function.
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Conference papers on the topic "Nested-grid"

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Katopodes, Nikolaos D., and Kuo-Cheng Kao. "Nested Grid Models for Ocean Processes." In ASME 2005 24th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2005. http://dx.doi.org/10.1115/omae2005-67212.

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This paper presents a novel two-way nested grid scheme that allows information to travel freely through the computational boundaries of the grid interface. The method tentatively assumes the pressure boundary conditions between subdomains, but uses a receding boundary approach to minimize the pressure errors. Initially, the domains overlap, but within a few time steps the overlap is eliminated by the receding boundaries, so repeated use of approximate boundary conditions is avoided. This prevents the accumulation of errors on the subdomain boundaries and, furthermore, decreases the transfer of errors to the rest of the domain by continuously discarding boundary data. To avoid continuous shrinking of the subdomains, the boundaries are reset to their original positions every few time steps. Successful applications of the method are presented for surface wave propagation, gravity currents and a combination of both surface and internal waves.
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Zhai, Li, and Jinyu Sheng. "Assimilating Hydrographic Observations into a Nested-Grid Coastal Circulation Model." In 10th International Conference on Estuarine and Coastal Modeling. Reston, VA: American Society of Civil Engineers, 2008. http://dx.doi.org/10.1061/40990(324)17.

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Ashtiani, Nima Amouzegar, S. Ali Khajehoddin, and Masoud Karimi-Ghartemani. "Optimal Design of Nested Current and Voltage Loops in Grid-Connected Inverters." In 2020 IEEE Applied Power Electronics Conference and Exposition (APEC). IEEE, 2020. http://dx.doi.org/10.1109/apec39645.2020.9124405.

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Tsuruya, Hiroichi, Kazuo Murakami, and Isao Irie. "Numerical Simulations of Mud Transport by a Multi-Layered Nested Grid Model." In 22nd International Conference on Coastal Engineering. New York, NY: American Society of Civil Engineers, 1991. http://dx.doi.org/10.1061/9780872627765.229.

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Song, Jingjun, Lijuan Shi, Shitian Zhang, Qinliang Li, and Lixia Yang. "Research on Non-uniform Nested Grid FDTD Method Based on Ionospheric Zakharov Model." In 2018 12th International Symposium on Antennas, Propagation and EM Theory (ISAPE). IEEE, 2018. http://dx.doi.org/10.1109/isape.2018.8634033.

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Wang, Z. "A fast nested multi-grid viscous flow solver for adaptive Cartesian/Quad grids." In Fluid Dynamics Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1996. http://dx.doi.org/10.2514/6.1996-2091.

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Wang, Yanzhi, Xue Lin, and Massoud Pedram. "Coordination of the smart grid and distributed data centers: A nested game-based optimization framework." In 2014 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT). IEEE, 2014. http://dx.doi.org/10.1109/isgt.2014.6816386.

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Sheng, Jinyu, and Bo Yang. "A Five-Level Nested-Grid Coastal Ocean Circulation Prediction System for Canadian Atlantic Coastal Waters." In 10th International Conference on Estuarine and Coastal Modeling. Reston, VA: American Society of Civil Engineers, 2008. http://dx.doi.org/10.1061/40990(324)3.

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Ngo, Van-Quang-Binh, Huu-Nhan Nguyen, Sorin Olaru, and Pedro Rodriguez-Ayerbe. "Model Predictive Control of Grid-Tie Nested Neutral Point Clamped Inverter for Megawatt Power Conversion Systems." In 2020 24th International Conference on System Theory, Control and Computing (ICSTCC). IEEE, 2020. http://dx.doi.org/10.1109/icstcc50638.2020.9259722.

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Zhai, Xiaoming, Jinyu Sheng, and Richard Greatbatch. "A New Two-Way Nested-Grid Ocean Modeling Technique Applied to the Scotian Shelf and Slope." In Eighth International Conference on Estuarine and Coastal Modeling. Reston, VA: American Society of Civil Engineers, 2004. http://dx.doi.org/10.1061/40734(145)22.

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Reports on the topic "Nested-grid"

1

Ginis, Isaac, and Lewis M. Rothstein. Coupled Atmosphere-Ocean Modeling Program Using Movable Nested Grid Techniques. Fort Belvoir, VA: Defense Technical Information Center, August 2001. http://dx.doi.org/10.21236/ada625173.

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Kao, C. Y. J., D. L. Langley, J. M. Reisner, and W. S. Smith. Development of the first nonhydrostatic nested-grid grid-point global atmospheric modeling system on parallel machines. Office of Scientific and Technical Information (OSTI), November 1998. http://dx.doi.org/10.2172/674906.

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