Results 271 to 280 of about 20,159 (298)
Strip Planarity Testing for Embedded Planar Graphs [PDF]
Algorithmica, 2016 In this paper we introduce and study the strip planarity testing problem, which takes as an input a planar graph $G(V,E)$ and a function $γ:V \rightarrow \{1,2,\dots,k\}$ and asks whether a planar drawing of $G$ exists such that each edge is monotone in the $y$-direction and, for any $u,v\in V$ with $γ(u)
Patrizio Angelini +2 more
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Some of the next articles are maybe not open access.
SIAM Journal on Discrete Mathematics, 1994
A separator in a graph \(G\) is a partition \((A,B,C)\) of \(V(G)\) such that \(| A|\), \(| B|\leq {2\over 3}| V(G)|\) and no vertex in \(A\) is adjacent to any vertex in \(B\); its order is \(| C|\). The authors give a short proof of a theorem of Lipton and Tarjan that for any planar graph with \(n\) vertices there is a separator of order \(\leq 2 ...
Noga Alon +2 more
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A separator in a graph \(G\) is a partition \((A,B,C)\) of \(V(G)\) such that \(| A|\), \(| B|\leq {2\over 3}| V(G)|\) and no vertex in \(A\) is adjacent to any vertex in \(B\); its order is \(| C|\). The authors give a short proof of a theorem of Lipton and Tarjan that for any planar graph with \(n\) vertices there is a separator of order \(\leq 2 ...
Noga Alon +2 more
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HV-planarity: Algorithms and complexity
Journal of Computer and System Sciences, 2019 An HV-graph is a planar graph with vertex-degree at most four such that each edge is labeled either H (horizontal) or V (vertical). The HV-planarity testing problem asks whether an HV-graph admits an HV-drawing, that is, a planar drawing such that each ...
Walter Dídimo +2 more
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Planar and non-planar borepins
Molecular Physics, 1996Theoretical studies of borepin and its B-substituted derivatives show planar structures with weak out-of-plane bending modes, often leading to boat-shaped borepins. The lowest vibrational frequency of borepin is 167 cm-1 at both HF/6-31G* and MP2/6-31G* levels, compared to 248 cm-1 calculated for the isoelectronic tropylium ion.
JEROME SCHULMAN, RAYMOND DISCH
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On planarity and similarity restraints
Journal of Applied Crystallography, 2001 Planarity and similarity restraints are described using a unified framework for the computation layout. In both cases, the gradient and Hessian of the restraint residual with respect to atomic coordinates are derived.
Blanc, E., Paciorek, W.
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IEEE Transactions on Computers, 1981
Summary: Those bases which permit the realization of a planar crossover are characterized.
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Summary: Those bases which permit the realization of a planar crossover are characterized.
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Journal of Knot Theory and Its Ramifications, 2002
Let S be a connected open subset of 2-sphere S2 which is identified with the extended plane R2 ∪ {∞}. We assume that S contains the n segments {1, 2, …, n} × [-1, 1]. An n-lace ℓ (in S) is the union ℓ1 ∪ … ∪ ℓn of disjoint simple arcs in S such that ∂ ℓi = {(i, 1), (π (i),-1)}, i = 1, …, n, for some permutation π of {1, 2, …, n}.
Jin, GT Jin, Gyo Taek, Kim, H
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Let S be a connected open subset of 2-sphere S2 which is identified with the extended plane R2 ∪ {∞}. We assume that S contains the n segments {1, 2, …, n} × [-1, 1]. An n-lace ℓ (in S) is the union ℓ1 ∪ … ∪ ℓn of disjoint simple arcs in S such that ∂ ℓi = {(i, 1), (π (i),-1)}, i = 1, …, n, for some permutation π of {1, 2, …, n}.
Jin, GT Jin, Gyo Taek, Kim, H
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Communications in Contemporary Mathematics, 2000
An embedding of a space Y into the 3-sphere S 3 is said to be strictly achiral if its image is pointwise fixed by an orientation reversing homeomorphism of S 3 . A space Y is said to be abstractly planar if it can be embedded into the 2-sphere S
Jiang, Boju, Wang, Shicheng
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An embedding of a space Y into the 3-sphere S 3 is said to be strictly achiral if its image is pointwise fixed by an orientation reversing homeomorphism of S 3 . A space Y is said to be abstractly planar if it can be embedded into the 2-sphere S
Jiang, Boju, Wang, Shicheng
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Results in Mathematics, 1996
All rings that are planar near-rings are characterized and constructed. For each vector space over a nontrivial division ring there is precisely one isomorphism class of such rings.
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All rings that are planar near-rings are characterized and constructed. For each vector space over a nontrivial division ring there is precisely one isomorphism class of such rings.
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Canadian Journal of Mathematics, 1975
A finite partially ordered set (poset) P is customarily represented by drawing a small circle for each point, with a lower than b whenever a < b in P, and drawing a straight line segment from a to b whenever a is covered by b in P (see, for example, G. Birkhoff [2, p. 4]). A poset P is planar if such a diagram can be drawn for P in which none of the
Kelly, David, Rival, Ivan
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A finite partially ordered set (poset) P is customarily represented by drawing a small circle for each point, with a lower than b whenever a < b in P, and drawing a straight line segment from a to b whenever a is covered by b in P (see, for example, G. Birkhoff [2, p. 4]). A poset P is planar if such a diagram can be drawn for P in which none of the
Kelly, David, Rival, Ivan
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