We consider the following variant of the well-known Monge-Kantorovich transportation problem. Let S be a set of n point sites in R. A bounded set C âŠ‚ R is to be distributed among the sites p âˆˆ S suchâ€¦ (More)

We consider the situation where one is given a set S of points in the plane and a collection D of unit disks embedded in the plane. We show that finding a minimum cardinality subset of D such thatâ€¦ (More)

Assume we are interested in solving a computational task, e.g., sorting n numbers, and we only have access to an unreliable primitive operation, for example, comparison between two numbers. Supposeâ€¦ (More)

We consider a visibility problem for two nonintersecting open or closed simple polygonal chains P and Q in the plane. The visibility area between P and Q is the union of all line segments pq where pâ€¦ (More)

Connecting some points in the plane by a road network is equivalent to constructing a finite planar graph G whose vertex set contains a predefined set of vertices (i. e., the possible destinations inâ€¦ (More)