5 citations · 21 across the 14 of their papers we have counts for
15 papers
A family of counterexamples for a conjecture of Berge on -diperfect digraphs
Caroline Aparecida de Paula Silva, Cândida Nunes da Silva, Orlando Lee
Let be a digraph. A stable set of and a path partition of are orthogonal if every path contains exactly one vertex of . In 1982…
-anti-circulant digraphs are -diperfect and BE-diperfect
Lucas Ismaily Bezerra Freitas, Orlando Lee
Let be a digraph. A subset of is a stable set if every pair of vertices in is non-adjacent in . A collection of disjoint paths of is a path…
Some results on Berge's conjecture and Begin-End conjecture
Lucas Ismaily Bezerra Freitas, Orlando Lee
Let be a digraph. A subset of is a stable set if every pair of vertices in is non-adjacent in . A collection of disjoint paths of is a path…
Some results on structure of all arc-locally (out) in-semicomplete digraphs
Lucas I. B. Freitas, Orlando Lee
Arc-locally semicomplete and arc-locally in-semicomplete digraphs were introduced by Bang-Jensen as a common generalization of both semicomplete and semicomplete bipartite digraphs…
Two novel results on the existence of -kernels in digraphs
Alonso Ali, Orlando Lee
Let be a digraph. We call a subset of -independent if for every pair of vertices , ; and we call it -absorbent if for every vertex…
Perfect digraphs
Cândida Nunes da Silva, Orlando Lee, Maycon Sambinelli
Let be a digraph. Given a set of vertices , an -path partition of is a collection of paths of such that $\{V(P) \colon P \in \mathcal…
Graphs with at most one crossing
André C. Silva, Alan Arroyo, R. Bruce Richter +1
The crossing number of a graph is the least number of crossings over all possible drawings of . We present a structural characterization of graphs with crossing number one.
Bounding the number of non-duplicates of the -side in simple drawings of
R. Bruce Richter, André C. Silva, Orlando Lee
The number is the smallest number of crossings in a simple planar drawing of in which both vertices on the 2-side have th…
Berge's Conjecture and Aharoni-Hartman-Hoffman's Conjecture for locally in-semicomplete digraphs
Maycon Sambinelli, Carla Negri Lintzmayer, Cândida Nunes da Silva +1
Let be a positive integer and let be a digraph. A path partition $\sP$ of is a set of vertex-disjoint paths which covers . Its -norm is defined as $\sum_{P \in…
Edge-magic labelings for constellations and armies of caterpillars
Márcia R. Cerioli, Cristina G. Fernandes, Orlando Lee +3
Let be an -vertex graph with edges. A function is an edge-magic labeling of if is bijective and, for some int…
On Gallai's and Hajós' Conjectures for graphs with treewidth at most 3
Fábio Botler, Maycon Sambinelli, Rafael S. Coelho +1
A path (resp. cycle) decomposition of a graph is a set of edge-disjoint paths (resp. cycles) of that covers the edge set of . Gallai (1966) conjectured that every graph…
Facility Leasing with Penalties
Murilo S. de Lima, Mário C. San Felice, Orlando Lee
In this paper we study the facility leasing problem with penalties. We present a primal-dual algorithm which is a 3-approximation, based on the algorithm by Nagarajan and Williamso…
On Linial's Conjecture for Spine Digraphs
Maycon Sambinelli, Cândida Nunes da Silva, Orlando Lee
In this paper we introduce a superclass of split digraphs, which we call spine digraphs. Those are the digraphs D whose vertex set can be partitioned into two sets X and Y such tha…
Spanning trees with nonseparating paths
Cristina G. Fernandes, César Hernández-Vélez, Orlando Lee +1
We consider questions related to the existence of spanning trees in graphs with the property that after the removal of any path in the tree the graph remains connected. We show tha…
A Faster Algorithm for Packing Branchings in Digraphs
Orlando Lee, Mario Leston Rey
We consider the problem of finding an integral packing of branchings in a capacitated digraph with root-set demands. Schrijver described an algorithm that returns a packing with at…