1,721,026 research outputs found
Data for the GMG Stokes paper
No full textThis repository contains source code, parameter files, and additional data used in the computations of the paper:
Thomas C. Clevenger and Timo Heister:
Comparison Between Algebraic and Matrix-free Geometric Multigrid for
a Stokes Problem on an Adaptive Mesh with Variable Viscosity
submitted, 2019
The data is available at https://github.com/tjhei/paper-gmg-stokes-dat
geodynamics/aspect: ASPECT 2.5.0
No full text<p>We are pleased to announce the release of ASPECT 2.5.0. ASPECT is the Advanced Solver for Problems in Earth's ConvecTion. It uses modern numerical methods such as adaptive mesh refinement, multigrid solvers, and a modular software design to provide a fast, flexible, and extensible mantle convection solver. ASPECT is available from</p>
<pre><code> https://aspect.geodynamics.org/
</code></pre>
<p>and the release is available from</p>
<pre><code> https://geodynamics.org/resources/aspect
</code></pre>
<p>and</p>
<pre><code> https://github.com/geodynamics/aspect/releases/tag/v2.5.0
</code></pre>
<p>Among others this release includes the following significant changes:</p>
<ul>
<li>
<p>ASPECT now includes version 0.5.0 of the Geodynamic World Builder. (Menno Fraters and other contributors)</p>
</li>
<li>
<p>ASPECT's manual has been converted from LaTeX to Markdown to be hosted as a website at <a href="https://aspect-documentation.readthedocs.io">https://aspect-documentation.readthedocs.io</a>. (Chris Mills, Mack Gregory, Timo Heister, Wolfgang Bangerth, Rene Gassmoeller, and many others)</p>
</li>
<li>
<p>New: ASPECT now requires deal.II 9.4 or newer. (Rene Gassmoeller, Timo Heister)</p>
</li>
<li>
<p>ASPECT now supports a DebugRelease build type that creates a debug build and a release build of ASPECT at the same time. It can be enabled by setting the CMake option CMAKE_BUILD_TYPE to DebugRelease or by typing "make debugrelease". (Timo Heister)</p>
</li>
<li>
<p>ASPECT now has a CMake option ASPECT_INSTALL_EXAMPLES that allows building and install all cookbooks and benchmarks. ASPECT now additionally installs the data/ directory. Both changes are helpful for installations that are used for teaching and tutorials. (Rene Gassmoeller)</p>
</li>
<li>
<p>Changed: ASPECT now releases the memory used for storing initial conditions and the Geodynamic World Builder after model initialization unless an owning pointer to these objects is kept. This reduces the memory footprint for models initialized from large data files. (Wolfgang Bangerth)</p>
</li>
<li>
<p>Added: Various helper functions to distinguish phase transitions for different compositions and compositional fields of different types. (Bob Myhill)</p>
</li>
<li>
<p>Added: The 'adiabatic' initial temperature plugin can now use a spatially variable top boundary layer thickness read from a data file or specified as a function in the input file. Additionally, the boundary layer temperature can now also be computed following the plate cooling model instead of the half-space cooling model. (Daniel Douglas, John Naliboff, Juliane Dannberg, Rene Gassmoeller)</p>
</li>
<li>
<p>New: ASPECT now supports tangential velocity boundary conditions with GMG for more geometries, such as 2D and 3D chunks. (Timo Heister, Haoyuan Li, Jiaqi Zhang)</p>
</li>
<li>
<p>New: Phase transitions can now be deactivated outside a given temperature range specified by upper and lower temperature limits for each phase transition. This allows implementing complex phase diagrams with transitions that intersect in pressure-temperature space. (Haoyuan Li)</p>
</li>
<li>
<p>New: There is now a postprocessor that outputs the total volume of the computational domain. This can be helpful for models using mesh deformation. (Anne Glerum)</p>
</li>
<li>
<p>New: Added a particle property 'grain size' that tracks grain size evolution on particles using the 'grain size' material model. (Juliane Dannberg, Rene Gassmoeller)</p>
</li>
<li>
<p>Fixed: Many bugs, see link below for a complete list. (Many authors. Thank you!).</p>
</li>
</ul>
<p>A complete list of all changes and their authors can be found at <a href="https://aspect.geodynamics.org/doc/doxygen/changes_between_2_84_80_and_2_85_80.html">https://aspect.geodynamics.org/doc/doxygen/changes_between_2_84_80_and_2_85_80.html</a></p>
<p>Wolfgang Bangerth, Juliane Dannberg, Menno Fraters, Rene Gassmoeller, Anne Glerum, Timo Heister, Bob Myhill, John Naliboff, and many other contributors.</p>
ASPECT v2.4.0
No full textWe are pleased to announce the release of ASPECT 2.4.0. ASPECT is the Advanced Solver for Problems in Earth\u27s ConvecTion. It uses modern numerical methods such as adaptive mesh refinement, multigrid solvers, and a modular software design to provide a fast, flexible, and extensible mantle convection solver. ASPECT is available from https://aspect.geodynamics.org/ and the release is available from https://geodynamics.org/resources/aspect and https://github.com/geodynamics/aspect/releases/tag/v2.4.0 Among others this release includes the following significant changes: New: ASPECT now requires deal.II 9.3.0 or newer, and cmake 3.1.0 or newer. (Timo Heister) New: The matrix-free GMG Stokes solver now works for problems with free-surface boundaries and elasticity. (Jiaqi Zhang, Anne Glerum, Timo Heister, John Naliboff) New: The matrix-free GMG Stokes preconditioner is now implemented for the Newton solver. (Timo Heister, Menno Fraters, Jiaqi Zhang) New: Visualization postprocessors now record the physical units of the quantity they compute, and this information is also output into visualization files with a sufficiently new version of deal.II. (Wolfgang Bangerth) New: Where possible, when using large data tables as input (e.g., for initial conditions specified as tables), these data are now stored only once on each node in memory areas that is accessible by all MPI processes on that node. (Wolfgang Bangerth) New: There is now a new material model for melting in the lowermost mantle. It can be used to reproduce the results of Dannberg et al. (2021). (Juliane Dannberg) New: The geoid postprocessor can now handle a deforming mesh, in addition to the already existing option from the dynamic topography postprocessor output. (Maaike Weerdesteijn, Rene Gassmoeller, Jacky Austermann) New: There is now a \u27static\u27 option for the temperature field that is set-up similarly to the \u27static\u27 option for compositional fields. This allows the temperature field to be constant over time so you can still advect and build up elastic stresses. (Rebecca Fildes, Magali Billen) Changed: The least squares particle interpolation plugins now provide a bound preserving slope limiter that respects local bounds on each cell. (Mack Gregory, Gerry Puckett, Rene Gassmoeller) New: Add an advection field method that advects a compositional field according to Darcy\u27s Law. (Daniel Douglas) New: The material model \u27dynamic_friction\u27 has been integrated into a new rheology model friction_models that can be used together with the visco_plastic material model. (Esther Heckenbach) New: ASPECT now has a ThermodynamicTableLookup equation of state plugin, which allows material models to read in one or more Perple_X or HeFESTo table files. (Bob Myhill) Changed: The initial composition model called \u27ascii data\u27 can now read in 3d ascii datasets into a 2d model and slice the dataset in a user controlled plane. This allows it to make high-resolution 2d models of problems that use observational data (such as seismic tomography models). (Juliane Dannberg, Rene Gassmoeller) New: Added a new postprocessor which computes the parameter Mobility following Lourenco et al., 2020. (Elodie Kendall, Rene Gassmoeller, Anne Glerum and Bob Myhill) Improved: Particle operations have been significantly accelerated, in particular in combination with a recent deal.II version (9.4.0 or newer). (Rene Gassmoeller) New: Add a benchmark for load induced flexure with options for specifying sediment and rock material infilling the flexural moat. (Daniel Douglas) New: ASPECT now has a cookbook that uses the gravity postprocessor to compute gravity generated by S40RTS-based mantle density variations. (Cedric Thieulot) New: ASPECT now has a cookbook that shows how velocities can be prescribed at positions specified by an ASCII input file. (Bob Myhill) New: There is now a cookbook of kinematically driven oceanic subduction in 2D with isoviscous materials and without temperature effects. The cookbook model setup is based on Quinquis (2014). (Anne Glerum) New: There is now a cookbook that visualizes the phase diagram from results of a model run. This includes examples from the Visco-Plastic and Steinberger material model. (Haoyuan Li and Magali Billen) New: There is now a cookbook that reproduces convection models with a phase function from Christensen and Yuen, 1985. (Juliane Dannberg) Fixed: Many bugs, see link below for a complete list. (Many authors. Thank you!). A complete list of all changes and their authors can be found at https://aspect.geodynamics.org/doc/doxygen/changes_between_2_83_80_and_2_84_80.html Wolfgang Bangerth, Juliane Dannberg, Menno Fraters, Rene Gassmoeller, Anne Glerum, Timo Heister, Bob Myhill, John Naliboff, and many other contributors
ASPECT v2.3.0
No full textWe are pleased to announce the release of ASPECT 2.3.0. ASPECT is the Advanced Solver for Problems in Earth\u27s ConvecTion. It uses modern numerical methods such as adaptive mesh refinement, multigrid solvers, and a modular software design to provide a fast, flexible, and extensible mantle convection solver. ASPECT is available from https://aspect.geodynamics.org/ and the release is available from https://geodynamics.org/cig/software/aspect/ and https://github.com/geodynamics/aspect/releases/tag/v2.3.0 Among others this release includes the following significant changes: New: ASPECT now requires deal.II 9.2.0 or newer. (Timo Heister) New: ASPECT has a new, reproducible logo. (Rene Gassmoeller, Juliane Dannberg) New: Mesh deformation now also works in combination with particles. Instead of the end of the timestep, particles are now advected before solving the compositional field advection equations. In iterative advection schemes, the particle location is restored before each iteration. (Anne Glerum, Rene Gassmoeller, Robert Citron) New: ASPECT now supports the creation of visualization postprocessors that only output data on the surface of a model. An example is the surface stress visualization postprocessor. (Wolfgang Bangerth) New: A new class TimeStepping::Manager to control time stepping with a plugin architecture has been added. The architecture allows to repeat time steps if the time step length changes significantly. (Timo Heister) New: A mesh refinement plugin that allows to set regions of minimum and maximum refinement level between isosurfaces of solution variables. (Menno Fraters and Haoyuan Li) New: There is a new nullspace removal option \u27net surface rotation\u27, which removes the net rotation of the surface. (Rene Gassmoeller) New: Particle advection can now be used in combination with the repetition of timesteps. Before each repetition the particles are restored to their previous position. (Anne Glerum) New: There is a new property in the depth average postprocessor that averages the mass of a compositional field (rather than its volume). (Juliane Dannberg) New: The Drucker Prager rheology module now has an option to include a plastic damper, which acts to stabilize the plasticity formulation. At sufficient resolutions for a given plastic damper viscosity, the plastic shear band characteristics will be resolution independent. (John Naliboff and Cedric Thieulot) New: ASPECT can now compute viscosity values depending on the values of phase functions for an arbitrary number of phases. (Haoyuan Li, 2020/08/06) New: Added calculation for temperature-dependent strain healing in the strain dependent rheology module. (Erin Heilman) New: Added new rheology module, which computes the temperature dependent Frank Kamenetskii viscosity approximation. (Erin Heilman) New: ASPECT now includes a CompositeViscoPlastic rheology module. This rheology is an isostress composite of diffusion, dislocation and Peierls creep rheologies and optionally includes a damped Drucker-Prager plastic element. The rheology module for Peierls creep includes a formulation to compute the exact Peierls viscosity, using an internal Newton-Raphson iterative scheme. (Bob Myhill, John Naliboff and Magali Billen) New: There is a new visualization postprocessor \u27principal stress\u27, which outputs the principal stress values and directions at every point in the model. (Rene Gassmoeller) New: Added the functionality to compute averages in user defined depth layers (e.g. lithosphere, asthenosphere, transition zone, lower mantle) to the depth average postprocessor and the lateral averaging plugin. (Rene Gassmoeller) New: The \u27spherical shell\u27 geometry model now supports periodic boundary conditions in polar angle direction for a 2D quarter shell (90 degree opening angle). (Kiran Chotalia, Timo Heister, Rene Gassmoeller) New: A new particle interpolator based on quadratic least squares has been added. (Mack Gregory, Gerry Puckett) New: There is now a mesh deformation plugin diffusion that can be used to diffuse surface topography in box geometry models. (Anne Glerum) Bug fixes to: Steinberger and Calderwood viscosity profile, particle generation, viscous strain weakening, incompressible equation of state, pressure sign convention, Neumann heat flow boundaries with the Newton solver, viscosity on the adiabat for extended Boussinesq approximation models, and many more. (many authors) A complete list of all changes and their contributing authors can be found at https://aspect.geodynamics.org/doc/doxygen/changes_between_2_82_80_and_2_83_80.html Wolfgang Bangerth, Juliane Dannberg, Menno Fraters, Rene Gassmoeller, Anne Glerum, Timo Heister, Bob Myhill, John Naliboff, and many other contributors
ASPECT v2.4.0
No full textWe are pleased to announce the release of ASPECT 2.4.0. ASPECT is the Advanced
Solver for Problems in Earth's ConvecTion. It uses modern numerical methods such
as adaptive mesh refinement, multigrid solvers, and a modular software design to
provide a fast, flexible, and extensible mantle convection solver. ASPECT is
available from
https://aspect.geodynamics.org/
and the release is available from
https://geodynamics.org/resources/aspect
and
https://github.com/geodynamics/aspect/releases/tag/v2.4.0
Among others this release includes the following significant changes:
New: ASPECT now requires deal.II 9.3.0 or newer, and cmake 3.1.0 or newer.
(Timo Heister)
New: The matrix-free GMG Stokes solver now works for problems with
free-surface boundaries and elasticity.
(Jiaqi Zhang, Anne Glerum, Timo Heister, John Naliboff)
New: The matrix-free GMG Stokes preconditioner is now implemented for the
Newton solver.
(Timo Heister, Menno Fraters, Jiaqi Zhang)
New: Visualization postprocessors now record the physical units of the
quantity they compute, and this information is also output into visualization
files with a sufficiently new version of deal.II.
(Wolfgang Bangerth)
New: Where possible, when using large data tables as input (e.g., for initial
conditions specified as tables), these data are now stored only once on each
node in memory areas that is accessible by all MPI processes on that node.
(Wolfgang Bangerth)
New: There is now a new material model for melting in the lowermost mantle.
It can be used to reproduce the results of Dannberg et al. (2021).
(Juliane Dannberg)
New: The geoid postprocessor can now handle a deforming mesh, in addition to the
already existing option from the dynamic topography postprocessor output.
(Maaike Weerdesteijn, Rene Gassmoeller, Jacky Austermann)
New: There is now a 'static' option for the temperature field that is set-up
similarly to the 'static' option for compositional fields. This allows the
temperature field to be constant over time so you can still advect and build
up elastic stresses.
(Rebecca Fildes, Magali Billen)
Changed: The least squares particle interpolation plugins now provide a bound
preserving slope limiter that respects local bounds on each cell.
(Mack Gregory, Gerry Puckett, Rene Gassmoeller)
New: Add an advection field method that advects a compositional field
according to Darcy's Law.
(Daniel Douglas)
New: The material model 'dynamic_friction' has been integrated into a new
rheology model friction_models that can be used together with the
visco_plastic material model.
(Esther Heckenbach)
New: ASPECT now has a ThermodynamicTableLookup equation of state plugin,
which allows material models to read in one or more Perple_X or HeFESTo table
files.
(Bob Myhill)
Changed: The initial composition model called 'ascii data' can now read in 3d
ascii datasets into a 2d model and slice the dataset in a user controlled
plane. This allows it to make high-resolution 2d models of problems that use
observational data (such as seismic tomography models).
(Juliane Dannberg, Rene Gassmoeller)
New: Added a new postprocessor which computes the parameter "Mobility"
following Lourenco et al., 2020.
(Elodie Kendall, Rene Gassmoeller, Anne Glerum and Bob Myhill)
Improved: Particle operations have been significantly accelerated, in
particular in combination with a recent deal.II version (9.4.0 or newer).
(Rene Gassmoeller)
New: Add a benchmark for load induced flexure with options for specifying
sediment and rock material infilling the flexural moat.
(Daniel Douglas)
New: ASPECT now has a cookbook that uses the gravity postprocessor to
compute gravity generated by S40RTS-based mantle density variations.
(Cedric Thieulot)
New: ASPECT now has a cookbook that shows how velocities can be prescribed
at positions specified by an ASCII input file.
(Bob Myhill)
New: There is now a cookbook of kinematically driven oceanic subduction in 2D
with isoviscous materials and without temperature effects. The cookbook model
setup is based on Quinquis (2014).
(Anne Glerum)
New: There is now a cookbook that visualizes the phase diagram from results
of a model run. This includes examples from the Visco-Plastic and Steinberger
material model.
(Haoyuan Li and Magali Billen)
New: There is now a cookbook that reproduces convection models with a phase
function from Christensen and Yuen, 1985.
(Juliane Dannberg)
Fixed: Many bugs, see link below for a complete list.
(Many authors. Thank you!).
A complete list of all changes and their authors can be found at
https://aspect.geodynamics.org/doc/doxygen/changes_between_2_83_80_and_2_84_80.html
Wolfgang Bangerth, Juliane Dannberg, Menno Fraters, Rene Gassmoeller,
Anne Glerum, Timo Heister, Bob Myhill, John Naliboff,
and many other contributors
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
