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maxnodf: an R package for fair and fast comparisons of nestedness between networks [article]

Christoph Hoeppke, Benno I Simmons
2020 bioRxiv   pre-print
For example, for a large network with 3000 links, computation time was reduced from 50 minutes using the fastest existing algorithm to 11 seconds using maxnodf. maxnodf makes correctly-normalised nestedness  ...  Users thus have the choice between a fast algorithm with a less accurate estimate, a slower algorithm with a more accurate estimate, and an intermediate option.  ...  Improvements over the greedy algorithm can be obtained with an algorithm called hill climbing.  ... 
doi:10.1101/2020.03.20.000612 fatcat:idnirf6pj5hcxhevwpg6gxtm4u

Viscous anisotropy of textured olivine aggregates: 2. Micromechanical model

Lars N. Hansen, Clinton P. Conrad, Yuval Boneh, Philip Skemer, Jessica M. Warren, David L. Kohlstedt
2016 Journal of Geophysical Research - Solid Earth  
For the textural evolution, we develop a new model in which the director method is used to control the rate of grain rotation and the available slip systems in olivine are used to control the axis of rotation  ...  We use these new data to conduct inversions for the best parameters to characterize both the mechanical and textural evolution models.  ...  We compare modeled textures to textures measured in deformed samples using their calculated orientation distribution functions (ODFs).  ... 
doi:10.1002/2016jb013240 fatcat:7pe5vlwnuzgtlksq6aqiliyo6i

Texture and anisotropy

H-R Wenk, P Van Houtte
2004 Reports on progress in physics (Print)  
Conventionally x-ray polefigure goniometers are used. More recently single orientation measurements are performed with electron microscopes, both SEM and TEM.  ...  One set of methods works in direct space and uses basically algorithms of tomography. The Williams-Imhof-Matthies-Vinel (WIMV) method, introduced by Matthies and Vinel (1982) , is most widely used.  ...  Omissions of odd coefficients can introduce errors in orientation densities in the ODF and add spurious maxima and minima, called ghosts (Kallend 2000) .  ... 
doi:10.1088/0034-4885/67/8/r02 fatcat:f7iff6qme5hqxctdnu4gcf65pe

Microstructural Origin of Residual Stress

Arijit Lodh
Residual stresses, on the other hand, were measured with multiple {hkl} GIXRD (grazing incident X-ray diffraction), micro-Laue diffraction (for single-crystal stress measurements) and residual stress ODFs  ...  Dislocation positions were updated incrementally using a forward Euler algorithm in both the glide and climb steps.  ...  The exact algorithm used for these measurements/analysis is given in the appendix.  ... 
doi:10.26180/5c90703200aab fatcat:g7rhjfkqm5bzdkbhfbkwohzzvq

Robust Motion and Distortion Correction of Diffusion-Weighted MR Images

Jan Hering
A heuristic approach tries to iteratively improve an initial solution guess, either in a constructive manner (greedy algorithms) or by means of a local search in the optimization space (hill-climbing,  ...  The DTI model is not capable of resolving the crossing resulting into an oblate shape whereas the ODF shows multiple maxima at such voxels. b=0 s·mm −2 Fiber configuration DTI ODF Figure 2.4:  ... 
doi:10.11588/heidok.00022242 fatcat:gwwqbx4ylfdnvofq2lk6ytrpry

Applied Machine Learning to Predict Stress Hotspots in Materials

Ankita Mangal
This data is used to create input feature vectors to train a random forest learning algorithm, which predicts the grains that become stress hotspots.  ...  Inspired by the recent advances in the deep learning fi eld, we also explore using these techniques to automatically extract long range microstructural descriptors.  ...  These algorithms are computationally efficient and scale as O(N logN ), where N is the number of discrete grid points.  ... 
doi:10.1184/r1/7235267 fatcat:u4d3c2ourrhm7cqplbghaki4xq

Evolution of Olivine Crystallographic Preferred Orientation in the Upper Mantle __ Implications for the Interpretation of Seismic Anisotropy

Yuval Boneh
. 70 Texture strength is quantified using statistical tools either related to the orientation distribution function (ODF) using the 'J-index' (J) (Bunge, 2013) , or by the distribution of misorientation  ...  Extrapolation of unindexed pixels was performed using an HKL noise reduction algorithm, in which pixels with five adjacent pixels with common orientation were filled.  ...  In this study, two commonly-used numerical models for simulating olivine CPO, VPSC and D-Rex, using the parameterization developed in Chapter 3 , are used to reproduce four different deformation configurations  ... 
doi:10.7936/k70c4t65 fatcat:w5wajvklejbvpbilfhktewh7vu

An exploratory study of dislocation relaxation in polycrystalline olivine [article]

Robert Jacobus Maria Farla, University, The Australian National, University, The Australian National
They were calculated using HKL Salsa (Oxford Instruments) from an orientation distribution function (ODF) with Lmax = 20 as the highest harmonic for the series expansion.  ...  These displacements were measured on the computer in the time domain.  ...  The electron penetration depth and depth of information, d was approximated using Monte Carlo (MC) electron interaction simulations.  ... 
doi:10.25911/5d4d608c99196 fatcat:75uo2euuyrgnplb22ivw7vvymy