2 citations · 3 across the 11 of their papers we have counts for
11 papers · 1 filter
DP-3-colorability of planar graphs without cycles of length 4, 7 or 9
Yingli Kang, Ligang Jin, Xuding Zhu
This paper proves that every planar graph without cycles of length 4, 7, or 9 is DP-3-colorable.
A study on parity signed graphs: the number
Ligang Jin, Xiaoyue Chen, Yingli Kang
The study on parity signed graphs was initiated by Acharya and Kureethara very recently and then followed by Zaslavsky etc.. Let be a signed graph on vertices. If $(G,σ…
Partially normal 5-edge-colorings of cubic graphs
Ligang Jin, Yingli Kang
In a proper edge-coloring of a cubic graph, an edge is normal if the set of colors used by the edges adjacent to has cardinality 3 or 5. The Petersen coloring conjecture as…
Hajós-like theorem for signed graphs
Yingli Kang
The paper designs five graph operations, and proves that every signed graph with chromatic number can be obtained from all-positive complete graphs by repeatedly appl…
Remarks on planar edge-chromatic critical graphs
Ligang Jin, Yingli Kang, Eckhard Steffen
The only open case of Vizing's conjecture that every planar graph with is a class 1 graph is . We give a short proof of the following statement: there is no 6-criti…
Plane graphs without 4- and 5-cycles and without ext-triangular 7-cycles are 3-colorable
Ligang Jin, Yingli Kang, Michael Schubert +1
Listed as No. 53 among the one hundred famous unsolved problems in [J. A. Bondy, U. S. R. Murty, Graph Theory, Springer, Berlin, 2008] is Steinberg's conjecture, which states that…
The chromatic spectrum of signed graphs
Yingli Kang, Eckhard Steffen
The chromatic number of a signed graph is the smallest number for which there is a function such that $c(v) \not= σ(e) c(…
Circular coloring of signed graphs
Yingli Kang, Eckhard Steffen
Let ( be two positive integers. We generalize the well studied notions of -colorings and of the circular chromatic number to signed graphs. This imp…
The 3-colorability of planar graphs without cycles of length 4, 6 and 9
Yingli Kang, Ligang Jin, Yingqian Wang
In this paper, we prove that planar graphs without cycles of length 4, 6, 9 are 3-colorable.
Choosability in signed planar graphs
Ligang Jin, Yingli Kang, Eckhard Steffen
This paper studies the choosability of signed planar graphs. We prove that every signed planar graph is 5-choosable and that there is a signed planar graph which is not 4-choosable…
Face-degree bounds for planar critical graphs
Ligang Jin, Yingli Kang, Eckhard Steffen
The only remaining case of a well known conjecture of Vizing states that there is no planar graph with maximum degree 6 and edge chromatic number 7. We introduce parameters for pla…