4 papers
On the Laplacian spectrum of -symmetric graphs
Sunyo Moon, Hyungkee Yoo
For some positive integer , if the finite cyclic group can act freely on a graph , then we say that is -symmetric. In 1985, Faria showed that the multip…
Petal number of torus knots using superbridge indices
Hyoungjun Kim, Sungjong No, Hyungkee Yoo
A petal projection of a knot is a projection of a knot which consists of a single multi-crossing and non-nested loops. Since a petal projection gives a sequence of natural numb…
Lattice stick number of spatial graphs
Hyungkee Yoo, Chaeryn Lee, Seungsang Oh
The lattice stick number of knots is defined to be the minimal number of straight sticks in the cubic lattice required to construct a lattice stick presentation of the knot. We sim…
Bisected vertex leveling of plane graphs: braid index, arc index and delta diagrams
Sungjong No, Seungsang Oh, Hyungkee Yoo
In this paper, we introduce a bisected vertex leveling of a plane graph. Using this planar embedding, we present elementary proofs of the well-known upper bounds in terms of the mi…