65 citations · 313 across the 28 of their papers we have counts for
14 papers · 1 filter
On the circuit diameter of dual transportation polyhedra
Steffen Borgwardt, Elisabeth Finhold, Raymond Hemmecke
In this paper we introduce the circuit diameter of polyhedra, which is always bounded from above by the combinatorial diameter. We consider dual transportation polyhedra defined on…
On the Connectivity of Fiber Graphs
Raymond Hemmecke, Tobias Windisch
We consider the connectivity of fiber graphs with respect to Gröbner basis and Graver basis moves. First, we present a sequence of fiber graphs using moves from a Gröbner basis and…
Lower bounds on the Graver complexity of -fold matrices
Elisabeth Finhold, Raymond Hemmecke
In this paper, we present a construction that turns certain relations on Graver basis elements of an -fold matrix into relations on Graver basis elements of an …
Challenging computations of Hilbert bases of cones associated with algebraic statistics
Winfried Bruns, Raymond Hemmecke, Bogdan Ichim +2
In this paper we present two independent computational proofs that the monoid derived from contingency tables is normal, completing the classification by Hibi a…
Multicommodity Flow in Polynomial Time
Raymond Hemmecke, Shmuel Onn, Robert Weismantel
The multicommodity flow problem is NP-hard already for two commodities over bipartite graphs. Nonetheless, using our recent theory of n-fold integer programming and extensions deve…
Computation of Atomic Fibers of Z-Linear Maps
Elke Eisenschmidt, Raymond Hemmecke, Matthias Köppe
For given matrix , the set describes the preimage or fiber of under the -linear map , $x\mapsto…