It is shown that every polyhedron in R3 with m edges can be guarded with at most 27 32m edge guards. The bound improves to 6m + 1 12 if the 1-skeleton of the polyhedron is connected. These are the first non-trivial upper bounds for the edge guard problem for general polyhedra in R3.

A universal tiler is a convex polyhedron whose every cross-section tiles the plane. In this paper, we introduce a slight-rotating operation for cross-sections of polyhedra. By applying the operation to suitably chosen cross-sections, we prove that a convex polyhedron is a universal tiler if and only if it is a tetrahedron or a pentahedron with parallel facets.

A submodular polyhedron is a polyhedron associated with a submodular function. This paper presents a strongly polynomial time algorithm for line search in submodular polyhedra with the aid of a fully combinatorial algorithm for submodular function minimization. The algorithm is based on the parametric search method proposed by Megiddo.

In Arc Routing Problems, ARPs, the aim is to find on a graph a minimum cost traversal satisfying some conditions related to the links of the graph. Due to restrictions to traverse some streets in a specified way, most applications of ARPs must be modeled with a mixed graph. Although several exact algorithms have been proposed, no polyhedral investigations have been done for ARPs on a mixed grap...

Supramolecular assembly is a powerful strategy used by nature to build nanoscale architectures with predefined sizes and shapes. With synthetic systems, however, numerous challenges remain to be solved before precise control over the synthesis, folding and assembly of rationally designed three-dimensional nano-objects made of RNA can be achieved. Here, using the transfer RNA molecule as a struc...

These notes will be rather informal in many places. For more precision, refer to Lectures on Polytopes by Günter Ziegler [Zie95], Convex Polytopes by Branko Grünbaum [Grü67], An Introduction to Convex Polytopes by Arne Brøndsted [Brø83], and Convex Polytopes and the Upper Bound Conjecture by Peter McMullen and Geoffrey Shephard [MS71]. See also the handbook papers [BL93, KK95] We will be studyi...

Let G = (V; E) be a graph and T V be a node set. We call an edge set S a Steiner tree with respect to T if S connects all pairs of nodes in T. In this paper we address the following problem, which we call the weighted Steiner tree packing problem. Given a graph G = (V; E) with edge weights w e , edge capacities a Steiner tree with respect to T k , at most c e of these edge sets use edge e for e...

Polyhedra are an important basic structure in computational geometry. One of the most beautiful results concerning polyhedra is Cauchy’s theorem, which states that a convex polyhedron is uniquely defined by its graph, edge lengths and facial angles. (See Section 2 for definitions.) The proof of Cauchy’s theorem (see e.g. [2]) unfortunately is nonconstructive, and the only known algorithm to rec...