Gerold Jäger

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Scabies has been a scourge among human beings for thousands of years. Its worldwide occurrence with epidemics during war, famine, and overcrowding is responsible for an estimated 300 million people currently infested. Scabies refers to the various skin lesions produced by female mites, and their eggs and scybala that are deposited in the epidermis, leading(More)
In this paper we introduce an extension of the Traveling Salesman Problem (TSP), which is motivated by an important application in bioinformatics. In contrast to the TSP the costs do not only depend on each pair of two nodes traversed in succession in a cycle but on each triple of nodes traversed in succession. This problem can be formulated as optimizing a(More)
This work presents a Boolean satisfiability (SAT) encoding for a special problem from combinatorial optimization. In the last years much progress has been made in the optimization of practical SAT solvers (see the SAT competition [5]). This has made SAT encodings for combinatorial problems highly attractive. In this work we propose an encoding for the(More)
In this paper we improve the analysis of approximation algorithms based on semidefinite programming for the maximum graph partitioning problems MAX-k-CUT, MAX-k-UNCUT, MAX-k-DIRECTEDCUT, MAX-k-DIRECTED-UNCUT, MAX-k-DENSE-SUBGRAPH, and MAX-k-VERTEX-COVER. It was observed by Han, Ye, Zhang (2002) and Halperin, Zwick (2002) that a parameter-driven random(More)
We introduce two new combinatorial optimization problems, which are generalizations of the Traveling Salesman Problem (TSP) and the Assignment Problem (AP) and which we call Traveling Salesman Problem of Second Order (TSP2) and Assignment Problem of Second Order (AP2). TSP2 is motivated by an important application in bioinformatics, especially the Permuted(More)
Hermite and Smith normal form are important forms of matrices used in linear algebra. These terms have many applications in group theory and number theory. As the entries of the matrix and of its corresponding transformation matrices can explode during the computation, it is a very difficult problem to compute the Hermite and Smith normal form of large(More)
We consider the problem of connecting a set I of n inputs to a set O of N outputs (n ≤ N) by as few edges as possible, such that for each injective mapping f : I → O there are n vertex disjoint paths from i to f(i) of length k for a given k ∈ N. For k = Ω(logN + log n) Oruç [5] gave the presently best (n,N)-connector with O(N +n · log n) edges. For k = 2 we(More)