146 search results - page 2 / 30 » Connectivity of chamber graphs of buildings and related comp... |
STOC
2010
ACM
13 years 11 months ago
2010
ACM
We give the first polynomial-time approximation scheme (PTAS) for the Steiner forest problem on planar graphs and, more generally, on graphs of bounded genus. As a first step, w...
SSDBM
2005
IEEE
13 years 11 months ago
2005
IEEE
To discover knowledge or retrieve information from a relational database, a user often needs to find objects related to certain source objects. There are two main challenges in b...
ESA
2003
Springer
13 years 11 months ago
2003
Springer
We prove that various geometric covering problems, related to the Travelling Salesman Problem cannot be efficiently approximated to within any constant factor unless P = NP. This ...
COCOON
2003
Springer
13 years 11 months ago
2003
Springer
Abstract. We show that finding roots of Boolean matrices is an NPhard problem. This answers a twenty year old question from semigroup theory. Interpreting Boolean matrices as dire...
KDD
2003
ACM
14 years 6 months ago
2003
ACM
Large and complex graphs representing relationships among sets of entities are an increasingly common focus of interest in data analysis--examples include social networks, Web gra...