The universal cover TG of a connected graph G is the unique (possible infinite) tree covering G, i.e., that allows a locally bijective homomorphism from TG to G. Universal covers h...
A geometric graph is a labeled graph whose vertices are points in the 2D plane with an isomorphism invariant under geometric transformations such as translation, rotation, and scal...
—It is increasingly common to find graphs in which edges bear different types, indicating a variety of relationships. For such graphs we propose a class of reachability queries ...
Wenfei Fan, Jianzhong Li, Shuai Ma, Nan Tang, Ying...
The management of large databases of hierarchical (e.g., multi-scale or multilevel) image features is a common problem in object recognition. Such structures are often represented ...
Partially ordered sets labeled with k labels (k-posets) and their homomorphisms are examined. The homomorphicity order of k-posets is shown to be a distributive lattice. Homomorph...