Jürgen Schulze

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In this paper we describe a new parallel tabu search heuristic for the vehicle routing problem with time window constraints (VRPTW). The neighborhood structure we propose is based on simple customer shifts and allows to consider infeasible interim-solutions. Similar to the column generation approach used in exact algorithms , all routes generated by the(More)
BACKGROUND Probiotics are effective in inflammatory bowel diseases. Clinical effectiveness and dose dependency of E. coli Nissle (EcN) enemas were investigated in ulcerative colitis (UC). METHODS In a double-blind study, 90 patients with moderate distal activity in UC were randomly assigned to treatment with either 40, 20, or 10 ml enemas (N = 24, 23, 23)(More)
In most cases, acute diarrhoea will become self-limiting during the first few days after onset. For young children, however, health risks may develop when the disease lasts longer than 3 days. The purpose of the present trial was to determine whether the stool frequency of infants and toddlers suffering from acute diarrhoea could be normalised more quickly(More)
PURPOSE To study the therapeutic effects of probiotic Escherichia coli Nissle 1917 (EcN) in irritable bowel syndrome (IBS) and identify subgroups benefiting most. BACKGROUND Some trials investigating therapeutic effects in irritable bowel syndrome have shown benefits in IBS subgroups only. Probiotic treatment seems to be promising. METHODS Patients with(More)
In this paper we compare nested dissection orderings obtained by diierent graph bisection heuristics. In the context of parallel sparse matrix factorization the quality of an ordering is not only determined by its ll reducing capability, but also depends on the dif-culty with which a balanced mapping of the load onto the processors of the parallel computer(More)
This paper describes the novel use of volume rendering for the visualization of MICOM oceanographic data and the tracking of mesoscale eddies. We present methods for generating 3D volumetric data and describe how to use VIRVO to build an animation for MICOM Gulf Stream motion data. This put the data in a format that easily gives oceanog-raphers the ability(More)
We study different aspects of integrable boundary quantum field theories, focussing mostly on the " boundary sine-Gordon model " and its applications to condensed matter physics. The first part of the review deals with formal problems. We analyze the classical limit and perform semi-classical quantization. We show that the non-relativistic limit corresponds(More)
The Coulomb-gas description of minimal models is considered on the half plane. Screening prescriptions are developed by the perturbative expansion of the Liouville theory with imaginary coupling and with Neumann boundary condition on the bosonic field. To generate the conformal blocks of more general boundary conditions, we propose the insertion of boundary(More)