7 papers
Circular Coloring and Fractional Coloring in Planar Graphs
Xiaolan Hu, Jiaao Li
We study the following Steinberg-type problem on circular coloring: for an odd integer , what is the smallest number such that every planar graph of girth withou…
Fractional coloring of planar graphs of girth five
Zdeněk Dvořák, Xiaolan Hu
A graph G is (a:b)-colorable if there exists an assignment of b-element subsets of {1,...,a} to vertices of G such that sets assigned to adjacent vertices are disjoint. We first sh…
The -good neighbor conditional diagnosability of locally exchanged twisted cubes
Huiqing Liu, Xiaolan Hu, Shan Gao
Connectivity and diagnosability are important parameters in measuring the fault tolerance and reliability of interconnection networks. The -vertex-connectivity of a connected…
A -choosable graph that is not -choosable
Zdeněk Dvořák, Xiaolan Hu, Jean-Sébastien Sereni
In 1980, Erdős, Rubin and Taylor asked whether for all positive integers , , and , every -choosable graph is also -choosable. We provide a negative answer…
(3a:a)-list-colorability of embedded graphs of girth at least five
Zdeněk Dvořák, Xiaolan Hu
A graph G is list (b:a)-colorable if for every assignment of lists of size b to vertices of G, there exists a choice of an a-element subset of the list at each vertex such that the…
Structure connectivity and substructure connectivity of twisted hypercubes
Dong Li, Xiaolan Hu, Huiqing Liu
Let be a graph and a certain connected subgraph of . The -structure connectivity (or resp., -substructure connectivity ) of is the minim…