3 papers
math.CO2007
Upper Bounds on the Number of Vertices of Weight <=k in Particular Arrangements of Pseudocircles
Ronald Ortner
In arrangements of pseudocircles (Jordan curves) the weight of a vertex (intersection point) is the number of pseudocircles that contain the vertex in its interior. We give improve…
math.CO2005
Embeddability of Arrangements of Pseudocircles into the Sphere
Ronald Ortner
An arrangement of pseudocircles is a finite set of oriented closed Jordan curves each two of which cross each other in exactly two points. To describe the combinatorial structure o…
math.CO2005
Combinations and Mixtures of Optimal Policies in Unichain Markov Decision Processes are Optimal
Ronald Ortner
We show that combinations of optimal (stationary) policies in unichain Markov decision processes are optimal. That is, let M be a unichain Markov decision process with state space…