Results 71 to 80 of about 5,946 (233)

Complexity of Hamiltonian Cycle Reconfiguration

open access: yesAlgorithms, 2018
The Hamiltonian cycle reconfiguration problem asks, given two Hamiltonian cycles C 0 and C t of a graph G, whether there is a sequence of Hamiltonian cycles C 0 , C 1 , … , C t such that C i can be obtained ...
Asahi Takaoka
doaj   +1 more source

Explicit 3‐colorings for Exponential Graphs

open access: yesJournal 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   +2 more
wiley   +1 more source

Saturated Partial Embeddings of Planar Graphs

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT In this work, we study how far one can deviate from optimal behavior when embedding a planar graph. For a planar graph G $G$, we say that a plane subgraph H ⊆ G $H\subseteq G$ is a plane‐saturated subgraph if adding any edge (possibly with new vertices) to H $H$ would either violate planarity or make the resulting graph no longer a subgraph of
Alexander Clifton, Nika Salia
wiley   +1 more source

A General Lower Bound on Gallai-Ramsey Numbers for Non-Bipartite Graphs

open access: yesTheory and Applications of Graphs, 2018
Given a graph $H$ and a positive integer $k$, the $k$-color Gallai-Ramsey number $gr_{k}(K_{3} : H)$ is defined to be the minimum number of vertices $n$ for which any $k$-coloring of the complete graph $K_{n}$ contains either a rainbow triangle or a ...
Colton Magnant
doaj   +1 more source

Soil Contamination Around the Copper Smelter and the Use of Soil Microarthropods as Bioindicators

open access: yesLand Degradation &Development, EarlyView.
ABSTRACT Soil contamination from smelter emissions, including heavy metals (HM), rare earth elements (REEs), and sulfur, poses a significant threat to soil ecosystems. In the immediate vicinity of the Głogów Copper Smelter, HM concentrations were several times higher than in more distant forest stands.
Jacek Malica   +10 more
wiley   +1 more source

Allocation of Indivisible Items With a Common Preference Graph: Minimizing Total Dissatisfaction

open access: yesNetworks, EarlyView.
ABSTRACT Allocating indivisible items among a set of agents is a frequently studied discrete optimization problem. In the setting considered in this work, the agents' preferences over the items are assumed to be identical. We consider a very recent measure for the overall quality of an allocation which does not rely on numerical valuations of the items.
Nina Chiarelli   +6 more
wiley   +1 more source

Strong Domination in Fuzzy Graphs

open access: yesFuzzy Information and Engineering, 2015
In this paper, the concept of strong domination number is introduced by using membership values of strong arcs in fuzzy graphs. The strong domination number γs of complete fuzzy graph and complete bipartite fuzzy graph is determined and bounds is ...
O.T. Manjusha, M.S. Sunitha
doaj   +1 more source

P3-Factorization of complete bipartite graphs

open access: yesDiscrete Mathematics, 1988
Let \(P_ 3\) be a path of 3 points and \(K_{m,n}\) be a complete bipartite graph with partite sets \(V_ 1\) and \(V_ 2\), where \(| V_ 1| =m\) and \(| V_ 2| =n.\) A spanning subgraph F of \(K_{m,n}\) is called a \(P_ 3\)-factor if each component of F is isomorphic to \(P_ 3\). If \(K_{m,n}\) is expressed as a line-disjoint sum of \(P_ 3\)-factors, then
openaire   +2 more sources

On the Complexity of the Paper Selection Problem for the Italian Research Quality Evaluation (VQR)

open access: yesNetworks, EarlyView.
ABSTRACT This work addresses the paper selection problem that each Italian university and department faced in the context of the research quality evaluation (VQR) of the Italian university system for the period 2020–2024. Given the set of researchers of a university and their associated papers, the problem consists of selecting a fixed number of ...
Francesco Carrabs   +2 more
wiley   +1 more source

ADAPT: An Autonomous Forklift for Construction Site Operation

open access: yesJournal of Field Robotics, EarlyView.
ABSTRACT Efficient material logistics are critical in controlling costs and schedules in the construction industry. However, manual material handling remains prone to inefficiencies, delays, and safety risks. Autonomous forklifts offer a solution to streamline on‐site logistics, reducing reliance on human operators and mitigating labor shortages.
Johannes Huemer   +12 more
wiley   +1 more source

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