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Showing 1 to 20 of 34 for “"Coarse-grid"”.
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Applicability of Coarse Grid Sandwich Construction for Use as Beam Webs
Made available in DSpace on 2014-12-08T23:57:11Z (GMT). No. of bitstreams: 1 6910699.pdf: 3470491 bytes, checksum: 60f92e9296503cac33bc6e1933ed7f11 (MD5) Previous issue date: 1968
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A New Method for the Rapid Calculation of Finely-Gridded Reservoir Simulation Pressures
A new method for the determination of finely-gridded reservoir simulation pressures has been developed. It is estimated to be as much as hundreds to thousands of times faster than other methods for very large reservoir simulation grids. The method extends the work of Weber et al. Weber demonstrated …
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Application of Neural Network Techniques to Downscale Precipitation
… climate models. Global climate models use a coarse grid of 300x300 Km2, while the resolution of interest for the hydrologist is 50x50 Km2.;Downscaling is the tool to map the large-scale global climate properties to a finer grid size in order to accurately predict climate variables such as …
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Multigrid methods for complex engineering geometries and unstructured meshes
The convergence of standard multigrid methods decays significantly if locally poor quality cells are present, and it is found that the poor convergence is due to the local failure of the smoothing property. The high frequency error localised in regions of low quality cells is not eliminated by …
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Multiscale Modeling and Simulation of Turbulent Geophysical Flows
… based approaches in the context of the multigrid/multiresolution methodologies, and (ii) deconvolution based spatial filtering approaches in the context of large eddy simulation techniques. In the first case, we developed a coarse-grid projection method that uses simple interpolation schemes …
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Efficient Setup Algorithms for Parallel Algebraic Multigrid
… experimental results motivate the design of new coarsening algorithms to improve the performance of coarse-grid selection itself. A new algorithm labeled Bucket Sorted Independent Sets (BSIS) is developed and contributes two major advances. First, the cost of selecting independent sets while …
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Investigation of Grid Adaptation to Reduce Computational Efforts for a 2-D Hydrogen-Fueled Dual-Mode Scramjet
… flow solver with various computational grids. Results are obtained for fuel-off, fuel-on non-reacting, and fuel-on reacting cases at different equivalence ratios. A one-step global chemical kinetics hydrogen-air model is used in conjunction with the eddy-dissipation model. Coarse, medium …
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Robust structured multigrid at extreme scales
… structure in a problem, robust structured multigrid methods gain important performance benefits because they preserve structure throughout the multigrid hierarchy. In parallel these methods benefit from nearest neighbor stencil-based communication patterns; however, the increased communication …
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Numerical evaluation of wind effects on buildings
… roof of a rectangular building are caused by the coarse grid used. To check this, a systematic evaluation of the k-$\varepsilon$ model method in predicting the wind pressure on flat roofs has been attempted by using grids of various densities. Computations were made for a low building and a taller …
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Wavelets and wavelet optimized-finite differences for electronic structure calculations
… [1], wavelets can also be used to determine a grid for finite difference calculations. In one dimension, starting with a guess for the wavefunction on a coarse grid with few points, an accurate solution on a nouniform grid can be evolved. In three dimensions, self-consistent total energy …
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Investigation of a grid induced turbulent environment for wind tunnel testing
… model tests of a two-dimensional nature, a grid constructed of 3.6 x 0.75 inch boards on 18 inch centers was used at the entrance of the tunnel. Important properties of the turbulent flow behind the uniform coarse grid were determined. The flow was found to be quite uniform at a distance of …
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PRINCESS AND THE PEA: THE IMPACT OF ROUGH TOPOGRAPHY ON DYNAMICS OF LARGE-SCALE SURFACE CIRCULATION PATTERNS
… understood and not properly represented in coarse-resolution models. This study investigates how ocean floor roughness, at the kilometer scale, influences the double-gyre circulation by utilizing a two-layer quasi-geostrophic model. Using Radko’s sandpaper theory, bottom drag is …
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Tracing the global carbon cycle with bomb radiocarbon
… this fate of radiocarbon is investigated using coarse-grid models to trace high-precision 14CO2 observations available in the atmosphere since the 1950s. The goal of the study is to progress our quantitative understanding of bomb radiocarbon following the pathways of the global carbon cycle. …
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Algebraic multigrid for stabilized finite element discretizations of the Navier Stokes equation
… Stokes equations on generalized unstructured grids is described. The method is based on an elemental agglomeration multigrid which produces a hierarchical sequence of coarse subspaces. Linear combinations of the basis functions from a given space form the next subspace and the use of the …
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Application of an inverse model in the community modeling effort results
… data of an eddy-resolving GCM ocean in the fine grid resolution of the GCM, the estimated horizontal circulation is statistically consistent with the EGCM time means in both patterns and values. Although the flow patterns are similar, the uncertainties for the GCM time means and the inverse model …
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Well-posedness and convergence of cfd two-fluid model for bubbly flows
… add artificial physics or numerically by using a coarse grid or first order methods. However, it eliminates the local physical instabilities along with the undesired high frequency oscillations resulting from the ill-posedness. Thus, the TFM loses the capability to predict the inherent local …
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Domain decomposition methods for time-harmonic elastic waves
… numerically two-level preconditioners,based on a coarse grid correction, this very simple idea giving promising results.
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A Finite-Element Coarse-GridProjection Method for Incompressible Flows
Coarse grid projection (CGP) methodology is a novel multigrid method for systems involving decoupled nonlinear evolution equations and linear elliptic Poisson equations. The nonlinear equations are solved on a fine grid and the linear equations are solved on a corresponding coarsened grid. Mapping …
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Pattern formation in fluid injection into dense granular media
… coupled with two fluid flow scheme, a fixed coarse grid scheme based on computational fluid dynamics (CFD) and a pore network modeling scheme. The numerical results from the two complementary methods reproduce phenomena consistent with the experimental observations and justify the concept of …
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Advances in spatial modeling for complex data with applications to symbolic data and spatial transcriptomics.
… a multivariate smoothing mechanism over the coarse grid, with efficient Bayesian inference facilitated through the Integrated Nested Laplace Approximation (INLA). A bivariate visualization tool is also developed to aid interpretation of the joint behavior of these features across space. …
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