A Randomized Parallel Three-Dimensional Convex Hull Algorithm for Coarse-Grained Multicomputers

1997 ◽  
Vol 30 (6) ◽  
pp. 547-558 ◽  
Author(s):  
F. Dehne ◽  
X. Deng ◽  
P. Dymond ◽  
A. Fabri ◽  
A. A. Khokhar
Keyword(s):  
Convex Hull ◽  
Three Dimensional ◽  
Coarse Grained ◽  
Convex Hull Algorithm

DRCH: A Method for 3D Convex Hull

2014 ◽  
Vol 571-572 ◽  
pp. 721-724
Author(s):  
Xiu Xun Huang ◽  
Ji Ting Zhou ◽  
Chen Ling ◽  
Wen Jun Zhang
Keyword(s):  
Convex Hull ◽  
Dimensionality Reduction ◽  
Time Complexity ◽  
Three Dimensional ◽  
Higher Dimensional ◽  
Point Set ◽  
Convex Hull Algorithm ◽  
Convex Hull Method

A novel three-dimensional (3D) convex hull method is proposed, which is called dimensionality reduction convex hull method (DRCH).Through having 3d point set map to 2d plane, most initial 3D points in the convex hull are removed. Then, the remaining points are to generate 3D convex hull using any convex hull algorithm. The experiment demonstrates 3D DRCH is faster than general 3D convex hull algorithms. Its time complexity is O(r log r), where r is the number of points not in the hull. And DRCH can be generalized to higher-dimensional problems.

scholarly journals Improved Convex Hull Algorithm Applied to Body Size Measurements

2021 ◽  
Vol 1790 (1) ◽  
pp. 012089
Author(s):  
Fang Qi ◽  
Sun GuangWu ◽  
Chen Yu
Keyword(s):  
Body Size ◽  
Convex Hull ◽  
Convex Hull Algorithm

scholarly journals On the forces that cable webs under tension can support and how to design cable webs to channel stresses

2019 ◽  
Vol 475 (2223) ◽  
pp. 20180781 ◽  
Author(s):  
Guy Bouchitté ◽  
Ornella Mattei ◽  
Graeme W. Milton ◽  
Pierre Seppecher
Keyword(s):  
Linear Programming ◽  
Convex Hull ◽  
Structural Engineering ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Finite Dimensional ◽  
Necessary And Sufficient

In many applications of structural engineering, the following question arises: given a set of forces f 1 ,  f 2 , …,  f N applied at prescribed points x 1 ,  x 2 , …,  x N , under what constraints on the forces does there exist a truss structure (or wire web) with all elements under tension that supports these forces? Here we provide answer to such a question for any configuration of the terminal points x 1 ,  x 2 , …,  x N in the two- and three-dimensional cases. Specifically, the existence of a web is guaranteed by a necessary and sufficient condition on the loading which corresponds to a finite dimensional linear programming problem. In two dimensions, we show that any such web can be replaced by one in which there are at most P elementary loops, where elementary means that the loop cannot be subdivided into subloops, and where P is the number of forces f 1 ,  f 2 , …,  f N applied at points strictly within the convex hull of x 1 ,  x 2 , …,  x N . In three dimensions, we show that, by slightly perturbing f 1 ,  f 2 , …,  f N , there exists a uniloadable web supporting this loading. Uniloadable means it supports this loading and all positive multiples of it, but not any other loading. Uniloadable webs provide a mechanism for channelling stress in desired ways.

scholarly journals Method for Vortex Shape Retrieval and Area Calculation Based on Convex Hull Algorithm

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 2706-2714
Author(s):  
Xu Wei ◽  
Jiyu Li ◽  
Bo Long ◽  
Xiaodan Hu ◽  
Han Wu ◽  
...  
Keyword(s):  
Convex Hull ◽  
Shape Retrieval ◽  
Convex Hull Algorithm

Riboswitch Folds to Holo-Form Like Structure Even in the Absence of Cognate Ligand at High Mg2+ Concentration

2021 ◽  
Author(s):  
Sunil Kumar ◽  
Govardhan Reddy
Keyword(s):  
Specific Binding ◽  
Three Dimensional ◽  
Coarse Grained ◽  
Thiamine Pyrophosphate ◽  
Initial Increase ◽  
Free Energy Surface ◽  
Physiological Concentration ◽  
Coarse Grained Model ◽  
Non Coding Rna ◽  
Thermodynamic Conditions

Riboswitches are non-coding RNA that regulate gene expression by folding into specific three-dimensional structures (holo-form) upon binding by their cognate ligand in the presence of Mg2+. Riboswitch functioning is also hypothesized to be under kinetic control requiring large cognate ligand concentrations. We ask the question under thermodynamic conditions, can the riboswitches populate holo-form like structures in the absence of their cognate ligands only in the presence of Mg2+. We addressed this question using thiamine pyrophosphate (TPP) riboswitch as a model system and computer simulations using a coarse-grained model for RNA. The folding free energy surface (FES) shows that with the initial increase in Mg2+ concentration ([Mg2+]), TPP AD undergoes a barrierless collapse in its dimensions. On further increase in [Mg2+], intermediates separated by barriers appear on the FES, and one of the intermediates has a TPP ligand-binding competent structure. We show that site-specific binding of the Mg2+ aids in the formation of tertiary contacts. For [Mg2+] greater than physiological concentration, AD folds into its holo-form like structure even in the absence of the TPP ligand. The folding kinetics shows that it populates an intermediate due to the misalignment of the two arms in the TPP AD, which acts as a kinetic trap leading to larger folding timescales. The predictions of the intermediate structures from the simulations are amenable for experimental verification.

A Convex Hull Algorithm for Minimization of Gibbs Energy in Two-Phase Multicomponent Alloys

2011 ◽  
Vol 172-174 ◽  
pp. 1214-1219
Author(s):  
Nataliya Perevoshchikova ◽  
Benoît Appolaire ◽  
Julien Teixeira ◽  
Sabine Denis
Keyword(s):  
Gibbs Energy ◽  
Convex Hull ◽  
Large Temperature ◽  
Two Phase ◽  
Multicomponent Alloys ◽  
General Dimension ◽  
Newton Raphson ◽  
Convex Hull Algorithm ◽  
Energy Hypersurface ◽  
Equilibrium Calculations

We have adapted the Quickhull algorithm with the general dimension Beneath-Beyondalgorithm [6] for computing the convex hull of the Gibbs energy hypersurface of multicomponenttwo-phase alloys. We illustrate the salient features of our method with calculations of isothermalferrite-austenite equilibria in Fe-C-Cr. Finally, successive equilibrium calculations in a Fe-C-Cr-Mosteel over a large temperature range show the benefit of computing the convex hull before performingthe conventional Newton-Raphson search.

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