Robert Nickel

Learn More
The development of nine infants with enlarged subarachnoid spaces identified by specific CT-scan criteria was prospectively followed to two to three years of age. Infants with intracranial hemorrhage, CNS anomaly, microcephaly or other factors of potentially major negative impact on their development were excluded. All study infants had normal or only(More)
Recently Hochstättler and Nešetřil introduced the flow lattice of an oriented matroid as generalization of the lattice of all integer flows of a digraph or more general a regular matroid. This lattice is defined as the integer hull of the characteristic vectors of signed circuits. Here, we characterize the flow lattice of oriented matroids that are uniform(More)
1 Motivation Signed graphs have been studied a lot during the last two decades. We address the vertex disjoint negative cycle packing problem posed by Zaslavsky [7, Problem II.A.1a]. Our aim is to find two vertex disjoint negative cycles in reasonable time which generalizes the problem of finding two vertex disjoint odd cycles in a graph. In the first stage(More)
We describe a new solution approach for order sequencing which reflects the build-to-order strategy of the European automobile industry. Therefore, it has to cope with a daily changing variety of customer orders. Each order consists of a set of commodities which are implemented while the order sequence passes through a body shop, a paint shop, and an(More)
1 Overview Let O be an oriented matroid on a ground set E with n elements and C its set of signed circuits. We identify a circuit C ∈ C with its signed characteristic vector χ C ∈ {0, ±1} n. In this paper we will discuss some questions concerning the integer lattice of C denoted by L(C) which are quite natural in the context of integer lattices: 1. What is(More)
The authors describe the Infant Motor Screen, which is a brief evaluation of the quality of motor patterns of preterm infants from four to 16 months of age. It was developed for use with an assessment of motor milestones as part of a developmental screening program for high-risk infants. 111 infants were tested at four months and 58 at eight months. The(More)