Results 11 to 20 of about 926,750 (319)
Graphs of Morphisms of Graphs [PDF]
The Electronic Journal of Combinatorics, 2008 This is an account for the combinatorially minded reader of various categories of directed and undirected graphs, and their analogies with the category of sets. As an application, the endomorphisms of a graph are in this context not only composable, giving a monoid structure, but also have a notion of adjacency, so that the set of endomorphisms is both
Ronald Brown +3 more
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Strong Oriented Chromatic Number of Planar Graphs without Short Cycles [PDF]
Discrete Mathematics & Theoretical Computer Science, 2008 Let M be an additive abelian group. An M-strong-oriented coloring of an oriented graph G is a mapping f from V(G) to M such that f(u) j(v) whenever uv is an arc in G and f(v)−f(u) −(f(t)−f(z)) whenever uv and zt are two arcs in G.
Mickael Montassier +2 more
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Planar Graphs as VPG-Graphs [PDF]
Journal of Graph Algorithms and Applications, 2013 Summary: A graph is \(B_k\)-VPG when it has an intersection representation by paths in a rectangular grid with at most \(k\) bends (turns). It is known that all planar graphs are \(B_3\)-VPG and this was conjectured to be tight. We disprove this conjecture by showing that all planar graphs are \(B_2\)-VPG.
Steven Chaplick, Torsten Ueckerdt
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Embedding Graphs into Embedded Graphs [PDF]
Algorithmica, 2020 A (possibly denerate) drawing of a graph $G$ in the plane is approximable by an embedding if it can be turned into an embedding by an arbitrarily small perturbation. We show that testing, whether a straight-line drawing of a planar graph $G$ in the plane is approximable by an embedding, can be carried out in polynomial time, if a desired embedding of ...
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Lietuvos Matematikos Rinkinys, 2021 In this paper, relations between discrete Sturm--Liouville problem with nonlocal integral boundary condition characteristics (poles, critical points, spectrum curves) and graphs characteristics (vertices, edges and faces) were found. The previous article
Jonas Vitkauskas, Artūras Štikonas
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A Visualization Tool for Flood Dynamics Monitoring Using a Graph-Based Approach
Remote Sensing, 2020 Insights into flood dynamics, rather than solely flood extent, are critical for effective flood disaster management, in particular in the context of emergency relief and damage assessment.
Bos Debusscher +2 more
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A note on graph theory techniques for brain tumor detection [PDF]
Romanian Journal of Neurology, 2022 Brain Tumors are detected in people of all age groups. It leads to various complications that are both physiological and psychological. Graph theory techniques are employed to study both functional and structural behavior of brain networks.
Yegnanarayanan Venkataraman
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Graph Powers and Graph Homomorphisms [PDF]
The Electronic Journal of Combinatorics, 2010 In this paper, we investigate some basic properties of fractional powers. In this regard, we show that for any non-bipartite graph $G$ and positive rational numbers ${2r+1\over 2s+1} < {2p+1\over 2q+1}$, we have $G^{2r+1\over 2s+1} < G^{2p+1\over 2q+1}$. Next, we study the power thickness of $G$, that is, the supremum of rational numbers ${2r+
Hossein Hajiabolhassan, Ali Taherkhani
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New Journal of Physics, 2021 The coherent Patterson function, derived from the coherent scattering intensities from N atoms, can be described as an auto-holographic image, i.e., the superposition of N -holographic images in which each atom serves as the source of a different ...
Irene Calvo-Almazán, Paul Fenter
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An Analysis of the Use of Graphs in People’s Daily Life
Revista Colombiana de Educación, 2021 This paper addresses the issue of the lack of connection between people’s knowledge and school mathematics. It is stated that this issue generates a phenomenon of opacity in People’s Daily Life and the uses of mathematical knowledge; this means that ...
José David Zaldívar-Rojas +1 more
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