On the existence of super-single designs with block size 4.
On the exponent of -regular primitive matrices.
On the failing cases of the Johnson bound for error-correcting codes.
On the Fundamental Group of self-affine plane Tiles
Let be an expanding matrix, a set with elements and define via the set equation . If the two-dimensional Lebesgue measure of is positive we call a self-affine plane tile. In the present paper we are concerned with topological properties of . We show that the fundamental group of is either trivial or uncountable and provide criteria for the triviality as well as the uncountability of . Furthermore, we give a short proof of the fact that the closure of each component of is a locally...
On the General Motion-Planning Problem with Two Degrees of Freedom.
On the generation and enumeration of some classes of convex polyominoes.
On the history of generalized quadrangles.
On the local linear independence of translates of a box spline
On the maximum positive semi-definite nullity and the cycle matroid of graphs.
On the Non-Existence of Certain M.D.S. Codes and Projective Planes.
On the norms of the random walks on planar graphs
We consider the nearest neighbor random walk on planar graphs. For certain families of these graphs, we give explicit upper bounds on the norm of the random walk operator in terms of the minimal number of edges at each vertex. We show that for a wide range of planar graphs the spectral radius of the random walk is less than one.
On the notion of transversal of a sum of matroids
On the number of fully packed loop configurations with a fixed associated matching.
On the number of matroids on a finite set.
On the number of non-isomorphic Steiner triples
On the number of orthogonal systems in vector spaces over finite fields.
On the number of possible row and column sums of -matrices.
On the orbits of Singer groups and their subgroups.
On the permanents of certain circulant matrices and related Toeplitz matrices. (Über die Permanente gewisser zirkulanter Matrizen und damit zusammenhängender Toeplitz-Matrizen.)
On the rank of random subsets of finite affine geometry
The aim of the paper is to give an effective formula for the calculation of the probability that a random subset of an affine geometry AG(r-1,q) has rank r. Tables for the probabilities are given for small ranks. The expected time to the first moment at which a random subset of an affine geometry achieves the rank r is derived.