Results 51 to 60 of about 327 (176)

Stable Cuts, NAC‐Colourings and Flexible Realisations of Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT A (2‐dimensional) realisation of a graph G $G$ is a pair ( G , p ) $(G,p)$, where p $p$ maps the vertices of G $G$ to R 2 ${{\mathbb{R}}}^{2}$. A realisation is flexible if it can be continuously deformed while keeping the edge lengths fixed, and rigid otherwise.
Katie Clinch, Dániel Garamvölgyi, John Haslegrave, Tony Huynh, Jan Legerský, Anthony Nixon   +5 more
wiley   +1 more source

Weak Degeneracy of Planar Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT The weak degeneracy of a graph G $G$ is a numerical parameter that was recently introduced by the first two authors with the aim of understanding the power of greedy algorithms for graph coloring. Every d $d$‐degenerate graph is weakly d $d$‐degenerate, but the converse is not true in general (e.g., all connected d $d$‐regular graphs except ...
Anton Bernshteyn, Eugene Lee, Evelyne Smith‐Roberge   +2 more
wiley   +1 more source

A Min–Max Relation on Dicuts and Dijoins in Weighted Chordal Digraphs

Journal of Graph Theory, EarlyView.
ABSTRACT In a digraph, a dicut is a cut where all the arcs cross in one direction. A dijoin is a subset of arcs that intersects every dicut. Edmonds and Giles conjectured that in a weighted digraph, the minimum weight of a dicut is equal to the maximum size of a packing of dijoins. This has been disproved. However, the unweighted version conjectured by
Gérard Cornuéjols, Siyue Liu, R. Ravi
wiley   +1 more source

Characterizing and computing the structure of clique intersections in strongly chordal graphs

Discrete Applied Mathematics, 2013
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Ragnar Nevries, Christian Rosenke
openaire   +1 more source

Explicit 3‐colorings for Exponential Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT In 1985, El‐Zahar and Sauer showed that the chromatic number of the direct product of two 4‐chromatic graphs is 4, establishing a nontrivial case of Hedetniemi's conjecture, which has since been refuted in general. Their proof uses the concept of an exponential graph, showing that if a graph H $H$ has no proper 3‐coloring, then the exponential
Adrien Argento, Pierre Charbit, Alantha Newman   +2 more
wiley   +1 more source

The Black-and-White Coloring Problem on Distance-Hereditary Graphs and Strongly Chordal Graphs [PDF]

, 2012
Given a graph G and integers b and w. The black-and-white coloring problem asks if there exist disjoint sets of vertices B and W with |B|=b and |W|=w such that no vertex in B is adjacent to any vertex in W. In this paper we show that the problem is polynomial when restricted to cographs, distance-hereditary graphs, interval graphs and strongly chordal ...
Ton Kloks, Sheung-Hung Poon, Feng-Ren Tsai, Yue-Li Wang   +3 more
openaire   +2 more sources

Looking at Soil as It Is: Evolution of Microscopic Soil Characterization From Kubiëna to Artificial Intelligence

Journal of Plant Nutrition and Soil Science, EarlyView.
We provide a historic overview of microscopic soil structure characterization from its founding father, Walter Kubiëna, to several technical revolutions like automation, digitalization, and artificial intelligence. In addition to technical advancements, we explore how concepts and research questions have evolved in time.
Steffen Schlüter, Maik Geers‐Lucas, Peter Kühn, Hans‐Jörg Vogel   +3 more
wiley   +1 more source

Beyond Directions: Symmetry‐Aware Rotation Sets for Triaxial Diffusion Encoding by Geometric Filter Optimization

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To improve the accuracy of diffusion‐weighted powder average signals for diffusion encoding with arbitrary b‐tensors. Methods We identify an intrinsic dihedral (D2$$ {D}_2 $$) symmetry of diffusion signals for arbitrary diffusion encoding, which defines their natural signal space (a quotient of 3D rotations).
Sune Nørhøj Jespersen, Filip Szczepankiewicz   +1 more
wiley   +1 more source

Process‐Structure‐Morphing Coupling in Thermally Activated ABS 4D Printing

Polymer Engineering &Science, EarlyView.
Graphical abstract illustrating thermally induced shape morphing in FDM‐printed ABS beams. ABSTRACT Predictable thermally induced morphing in fused deposition modeled thermoplastics remains difficult because the deformation response is highly sensitive to processing and activation conditions.
Grigorios Kostopoulos, Stelios K. Georgantzinos   +1 more
wiley   +1 more source

Koszul graded Möbius algebras and strongly chordal graphs

Selecta Mathematica
28 pages, to appear in Selecta ...
LaClair, Adam, Mastroeni, Matthew, McCullough, Jason, Peeva, Irena   +3 more
openaire   +3 more sources