160 search results - page 6 / 32 » Structural characterizations of schema-mapping languages |
ICALP
1999
Springer
13 years 12 months ago
1999
Springer
We introduce new techniques for studying the structure of partial k-trees. In particular, we show that the complements of partial k-trees provide an intuitively-appealing character...
CIKM
2011
Springer
12 years 7 months ago
2011
Springer
Social media services have spread throughout the world in just a few years. They have become not only a new source of information, but also new mechanisms for societies world-wide...
FOCS
2003
IEEE
14 years 28 days 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 ...
FOSSACS
2011
Springer
12 years 11 months ago
2011
Springer
To the best of our knowledge, we characterize for the first time the importance of resources (counters, channels, alphabets) when measuring expressiveness of WSTS. We establish, f...
TIME
2002
IEEE
14 years 16 days ago
2002
IEEE
Events employed in natural language semantics are characterized in terms of regular languages, each string in which can be regarded as a motion picture. The relevant finite autom...