Computer-aided design by optimization in architecture

This paper shows that optimization concepts are particularly useful in design because of their direct assistance in decision making. In this they subsume evaluation or appraisal techniques. One approach based on dynamic programming is presented as being directly applicable in computer-aided architectural design. Multi-attribute objectives in design can be handled using optimization concepts. Finally, multi-objective design, including multi-attribute multi-objective design, can be handled via the use of Pareto optimality approaches. The result of such processes is a solution database which the designer searches. The solution database contains information about the design decisions themselves as well as the performance of each solution in its various objectives. The designer still assumes responsibility for selecting particular solutions since there is no unique solution produced. It is suggested that any problem which can be manipulated quantitatively can be solved using these concepts.     

Disk-Elektrophorese der wasserl?slichen Proteine einiger Weizensorten

Die beschriebene Methode erlaubt eine zuverlässige Erkennung der Sorte Kranich aus insgesamt 9 untersuchten Weizensorten innerhalb von 5 Stunden.     

Energy in context: A multicriteria model for building design

A model is proposed for the representation and comparison of design alternatives which puts energy efficiency in a context of performances in other criteria. The model utilizes notions of decision and performance spaces and multicriteria Pareto optimization. A simple example is described.     

Interaction of amphiphilic polymers with model membranes

The lipid bilayers of cell membranes are usually connected to two types of biopolymers: the cytoskeleton and the glycocalix. These structures are not only responsible for the stabilization of the lipid bilayer, they also alter the surface properties of the cells. Among the various attempts to mimick membrane properties using polymeric systems(¹), one method is the fixation of amphiphilic polymers via hydrophobic anchor groups to lipid bilayers. In the experiments reported here the influence of amphiphilic polymers on the morphology of giant unilamellar liposomes has been investigated. Therefore a series of amphiphilic polyvinylpyrrolidone and dextran derivatives has been synthesized. The fixation of these polymers to the liposomal membranes could be shown with a fluorescence-labelled derivative by using epifluorescence microscopy. The polymer-membrane interaction caused by the insertion of the anchor groups leads to drastic morphological changes in this model membrane system. The exclusive interaction with the outer membrane of multilamellar liposomes could be demonstrated by freeze fracture electron microscopy. In addition, the anchoring of a natural capsular polysaccharide in liposomes has been proven by immunofluorescence. In these experiments, also a clustering (patching) of the antigen caused by the binding of the antibody could be observed.     

Integration of Gas Nitrocarburising and Oxidising in a Mass Production Line for Brake Pistons

The combination of wear- and corrosion resistance is a demand to a multitude of automotive parts. Several metallic coatings as hard/soft chromium or electroless nickel have been the conventional surface protection e.g. on parts as brake pistons and shock absorber or gas spring piston rods. The Corr-I-Dur^R process - a special gasnitrocarburising and oxidising technology - has a huge potential not only in substituting those coatings but also in delivering surfaces with higher quality.The benefits of the replacement of soft chromium with Corr-I-Dur^R and the implementation of the process in the customers production line with an annual capacity of 17 million brake pistons is described in this presentation. Starting with the demands on wear- and corrosion resistance the way of process development and the design of applicative equipment is shown. The result is a tailor-made surface solution with superior quality for deep drawn brake pistons. Two main disadvantages -outgassing of the chromium layer and reduced corrosion resistance on the inner diameter - are eliminated by the replacement with Corr-I-Dur^R. The process-sure achievement of enhanced corrosion resistance, uniform layer thickness, negligible distortion as well as environmental and economical advantages make Corr-I-Dur^R an excellence choice for this application.     

An Arbitrary Lagrangian–Eulerian Local Discontinuous Galerkin Method for Hamilton–Jacobi Equations

In this paper, an arbitrary Lagrangian–Eulerian local discontinuous Galerkin (ALE-LDG) method for Hamilton–Jacobi equations will be developed, analyzed and numerically tested. This method is based on the time-dependent approximation space defined on the moving mesh. A priori error estimates will be stated with respect to the \(\mathrm {L}^{\infty }\left( 0,T;\mathrm {L}^{2}\left( \Omega \right) \right) \)-norm. In particular, the optimal (\(k+1\)) convergence in one dimension and the suboptimal (\(k+\frac{1}{2}\)) convergence in two dimensions will be proven for the semi-discrete method, when a local Lax–Friedrichs flux and piecewise polynomials of degree k on the reference cell are used. Furthermore, the validity of the geometric conservation law will be proven for the fully-discrete method. Also, the link between the piecewise constant ALE-LDG method and the monotone scheme, which converges to the unique viscosity solution, will be shown. The capability of the method will be demonstrated by a variety of one and two dimensional numerical examples with convex and noneconvex Hamiltonian.     

Sinus endoscopy--application of advanced GPU volume rendering for virtual endoscopy

For difficult cases in endoscopic sinus surgery, a careful planning of the intervention is necessary. Due to the reduced field of view during the intervention, the surgeons have less information about the surrounding structures in the working area compared to open surgery. Virtual endoscopy enables the visualization of the operating field and additional information, such as risk structures (e.g., optical nerve and skull base) and target structures to be removed (e.g., mucosal swelling). The Sinus Endoscopy system provides the functional range of a virtual endoscopic system with special focus on a realistic representation. Furthermore, by using direct volume rendering, we avoid time-consuming segmentation steps for the use of individual patient datasets. However, the image quality of the endoscopic view can be adjusted in a way that a standard computer with a modern standard graphics card achieves interactive frame rates with low CPU utilization. Thereby, characteristics of the endoscopic view are systematically used for the optimization of the volume rendering speed. The system design was based on a careful analysis of the endoscopic sinus surgery and the resulting needs for computer support. As a small standalone application it can be instantly used for surgical planning and patient education. First results of a clinical evaluation with ENT surgeons were employed to fine-tune the user interface, in particular to reduce the number of controls by using appropriate default values wherever possible. The system was used for preoperative planning in 102 cases, provides useful information for intervention planning (e.g., anatomic variations of the Rec. Frontalis), and closely resembles the intraoperative situation.