scholarly journals Three-dimensional normal mode functions: open-access tools for their computation in isobaric coordinates (p-3DNMF.v1)

2020 ◽  
Vol 13 (6) ◽  
pp. 2763-2781
Author(s):  
Carlos A. F. Marques ◽  
Martinho Marta-Almeida ◽  
José M. Castanheira
Keyword(s):  
Atmospheric Circulation ◽  
Normal Mode ◽  
General Circulation ◽  
Spatial Scales ◽  
Three Dimensional ◽  
Normal Modes ◽  
Atmospheric Models ◽  
Atmospheric Motion ◽  
Global Atmospheric Circulation ◽  
User Friendly

Abstract. A free software package for the computation of the three-dimensional normal modes of an hydrostatic atmosphere is presented. This software performs the computations in isobaric coordinates and was developed for two user-friendly languages: MATLAB and Python. The software can be used to expand the global atmospheric circulation onto the 3-D normal modes. This expansion allows the computation of a 3-D energetic scheme, which partitions the energy reservoirs and energy interactions between 3-D spatial scales, barotropic and baroclinic components, and balanced (rotational) and unbalanced (divergent) circulation fields. Moreover, by retaining only a subset of the expansion coefficients, the 3-D normal mode expansion can be used for spatial-scale filtering of atmospheric motion, filtering of balanced motion and mass unbalanced motions, and barotropic and baroclinic components. Fixing the meridional scale, the 3-D normal mode filtering can be used to isolate tropical components of the atmospheric circulation. All of these features are useful both in data analysis and in assessment of general circulation atmospheric models.

scholarly journals Three-dimensional normal mode functions: Open access tools for their computation in isobaric coordinates (p-3DNMF.v1)

2020 ◽  
Author(s):  
Carlos A. F. Marques ◽  
Martinho Marta-Almeida ◽  
José M. Castanheira
Keyword(s):  
Atmospheric Circulation ◽  
Normal Mode ◽  
General Circulation ◽  
Spatial Scales ◽  
Three Dimensional ◽  
Normal Modes ◽  
3 Dimensional ◽  
Atmospheric Motion ◽  
Global Atmospheric Circulation ◽  
User Friendly

Abstract. A free software package for the computation of the 3-Dimensional Normal Modes of an hydrostatic atmosphere is presented. This software performs the computations in isobaric coordinates and was developed for two user friendly languages: MATLAB and Python. The software can be used to expand the global atmospheric circulation onto the 3-D Normal Modes. This expansion allows the computation of a 3-D energetic scheme which partition the energy reservoirs and energy interactions between 3-D spatial scales, and between barotropic and baroclinic components as well as between balanced (rotational) and unbalanced (divergent) circulation fields. Moreover, by retaining only a subset of the expansion coefficients, the 3-D normal mode expansion can be used for spatial scale filtering of atmospheric motion, and filtering of balanced motion and mass unbalanced motions, and barotropic and baroclinic components. Fixing the meridional scale, the 3-D normal mode filtering can be used to isolate tropical components of the atmospheric circulation. All these features are useful both in data analysis and in assessment of general circulation atmospheric models.

scholarly journals Fast Overlap Detection between Hard-Core Colloidal Cuboids and Spheres. The OCSI Algorithm

Algorithms ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 72
Author(s):  
Luca Tonti ◽  
Alessandro Patti
Keyword(s):  
Colloidal Particles ◽  
Dynamic Properties ◽  
Wide Spectrum ◽  
Three Dimensional ◽  
Hard Core ◽  
Detection Algorithm ◽  
Three Dimensional Objects ◽  
Aggregation Behaviour ◽  
Sphere Radius ◽  
User Friendly

Collision between rigid three-dimensional objects is a very common modelling problem in a wide spectrum of scientific disciplines, including Computer Science and Physics. It spans from realistic animation of polyhedral shapes for computer vision to the description of thermodynamic and dynamic properties in simple and complex fluids. For instance, colloidal particles of especially exotic shapes are commonly modelled as hard-core objects, whose collision test is key to correctly determine their phase and aggregation behaviour. In this work, we propose the Oriented Cuboid Sphere Intersection (OCSI) algorithm to detect collisions between prolate or oblate cuboids and spheres. We investigate OCSI’s performance by bench-marking it against a number of algorithms commonly employed in computer graphics and colloidal science: Quick Rejection First (QRI), Quick Rejection Intertwined (QRF) and a vectorized version of the OBB-sphere collision detection algorithm that explicitly uses SIMD Streaming Extension (SSE) intrinsics, here referred to as SSE-intr. We observed that QRI and QRF significantly depend on the specific cuboid anisotropy and sphere radius, while SSE-intr and OCSI maintain their speed independently of the objects’ geometry. While OCSI and SSE-intr, both based on SIMD parallelization, show excellent and very similar performance, the former provides a more accessible coding and user-friendly implementation as it exploits OpenMP directives for automatic vectorization.

Acoustic Green's Function Approximations

1998 ◽  
Vol 06 (04) ◽  
pp. 435-452 ◽  
Author(s):  
Robert P. Gilbert ◽  
Zhongyan Lin ◽  
Klaus Hackl
Keyword(s):  
Inverse Problem ◽  
Normal Mode ◽  
Eigenvalue Problems ◽  
Normal Modes ◽  
Modal Parameters ◽  
Mindlin Plate ◽  
Ocean Bottom ◽  
Hankel Transformation ◽  
Poroelastic Materials ◽  
Function Approximations

Normal-mode expansions for Green's functions are derived for ocean–bottom systems. The bottom is modeled by Kirchhoff and Reissner–Mindlin plate theories for elastic and poroelastic materials. The resulting eigenvalue problems for the modal parameters are investigated. Normal modes are calculated by Hankel transformation of the underlying equations. Finally, the relation to the inverse problem is outlined.

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