225 search results - page 2 / 45 » From polynomial time queries to graph structure theory |
IWOCA
2010
Springer
13 years 11 days ago
2010
Springer
A homomorphism from a graph G to a graph R is locally surjective if its restriction to the neighborhood of each vertex of G is surjective. Such a homomorphism is also called an R-r...
FQAS
2009
Springer
14 years 4 days ago
2009
Springer
We consider the problem of finding and ranking paths in semistructured data without necessarily knowing its full structure. The query language we adopt comprises conjunctions of r...
STACS
2009
Springer
14 years 10 days ago
2009
Springer
We present the first polynomial-time approximation schemes (PTASes) for the following subset-connectivity problems in edge-weighted graphs of bounded genus: Steiner tree, low-conn...
CSL
2010
Springer
13 years 5 months ago
2010
Springer
We study probabilistic complexity classes and questions of derandomisation from a logical point of view. For each logic L we introduce a new logic BPL, bounded error probabilistic ...
PODS
2006
ACM
14 years 5 months ago
2006
ACM
Data exchange deals with inserting data from one database into another database having a different schema. We study and solve a central computational problem of data exchange, nam...