328 search results - page 2 / 66 » Homomorphism bounded classes of graphs |
FOCS
2003
IEEE
14 years 1 months ago
2003
IEEE
We give a complexity theoretic classification of homomorphism problems for graphs and, more generally, relational structures obtained by restricting the left hand side structure ...
ICALP
2009
Springer
14 years 8 months ago
2009
Springer
We introduce a generic approach for counting subgraphs in a graph. The main idea is to relate counting subgraphs to counting graph homomorphisms. This approach provides new algori...
PODS
2004
ACM
14 years 8 months ago
2004
ACM
Unions of conjunctive queries, also known as select-project-join-union queries, are the most frequently asked queries in relational database systems. These queries are definable b...
STOC
2006
ACM
14 years 8 months ago
2006
ACM
Classes of graphs with bounded expansion have been introduced in [15], [12]. They generalize both proper minor closed classes and classes with bounded degree. For any class with b...
CSR
2009
Springer
14 years 3 months ago
2009
Springer
A homomorphism from a graph G to a graph H (in this paper, both simple, undirected graphs) is a mapping f : V (G) → V (H) such that if uv ∈ E(G) then f(u)f(v) ∈ E(H). The pro...