Monte Carlo simulations of the HP model (the "Ising model" of protein folding)

Using Wang-Landau sampling with suitable Monte Carlo trial moves (pull moves and bond-rebridging moves combined) we have determined the density of states and thermodynamic properties for a short sequence of the HP protein model. For free chains these proteins are known to first undergo a collapse "transition" to a globule state followed by a second "transition" into a native state. When placed in the proximity of an attractive surface, there is a competition between surface adsorption and folding that leads to an intriguing sequence of "transitions". These transitions depend upon the relative interaction strengths and are largely inaccessible to "standard" Monte Carlo methods.Comment: 6 pages, 6 figures. Article in press. To be published in Computer Physics Communications (2011

Generation of the transport service offer with application to timetable planning considering constraints due to maintenance work

Line planning is an important step in strategic timetable planning in public transport. In this step the transport offer for the customer is generated by the public transport operator, whereby the resulting costs for the operator should be as deep as possible. Mathematical models for line planning allow to create optimized line plans quickly. Planners can use these models to rate and select different alternatives. This is particularly valuable under the aspect of increasing maintenance and construction tasks of the railway infrastructure. We show, that in this case, it is possible to create functional requirements for automated timetable creation from the result of line planning step. The practical use of the involved models is illustrated by a real application example

The South African IDP and SDF contextualised in relation to global conceptions of forward planning – A review

Municipalities across the globe require good planning instruments to address the need for medium- to long-term planning. In South Africa, the Integrated Development Plan (IDP) and the Spatial Development Framework (SDF) could be regarded as the two main instruments in the system of forward planning, as mandated by the national government. The system, however, is over two decades old and is not without its detractors and, as such, fresh reviews are warranted. In investigating the instruments, it is the purpose of this review article, as a first step, to identify, compare and analyse several terms or phrases used in global literature in connection with forward planning, in particular blueprint or master planning, comprehensive planning, integrated planning, strategic planning, strategic spatial planning, and community planning. Finally, the article explores the IDP and SDF against the insights gained from this process