University of Paderborn

About: University of Paderborn is a education organization based out in Paderborn, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Control reconfiguration & Software. The organization has 6684 authors who have published 16929 publications receiving 323154 citations.

Adsorption and Desorption of an O 2 Molecule on Carbon Nanotubes

Abstract: Adsorption and desorption of an oxygen molecule on carbon nanotubes are investigated using density functional calculations. Several precursor states exist at the edge of armchair nanotubes, whereas an exothermic adsorption takes place at the edge of zigzag nanotubes. We also estimate desorption barriers of a CO molecule from nanotubes as well as fullerenes and amorphous phases. Our calculations suggest that carbon nanotubes can survive selectively during the oxidative etching process with a precise control of annealing temperature, in good agreement with experimental results of purification process of carbon nanotubes.

Modeling and validation of service-oriented architectures: application vs. style

Abstract: Most applications developed today rely on a given middleware platform which governs the interaction between components, the access to resources, etc. To decide, which platform is suitable for a given application (or more generally, to understand the interaction between application and platform), we propose UML models of both the architectural style of the platform and the application scenario. Based on a formal interpretation of these as graphs and graph transformation systems, we are able to validate the consistency between platform and application.

The randomized z-buffer algorithm: interactive rendering of highly complex scenes

Abstract: We present a new output-sensitive rendering algorithm, the randomized z-buffer algorithm. It renders an image of an arbitrary three-dimensional scene consisting of triangular primitives by reconstruction from a dynamically chosen set of random surface sample points. This approach is independent of mesh connectivity and topology. The resulting rendering time grows only logarithmically with the numbers of triangles in the scene. We were able to render walkthroughs of scenes of up to 1014 triangles at interactive frame rates. Automatic identification of low detail scene components ensures that the rendering speed of the randomized z-buffer cannot drop below that of conventional z-buffer rendering. Experimental and analytical evidence is given that the image quality is comparable to that of common approaches like z-buffer rendering. The precomputed data structures employed by the randomized z-buffer allow for interactive dynamic updates of the scene. Their memory requirements grow only linearly with the number of triangles and allow for a scene graph based instantiation scheme to further reduce memory consumption.

Inter-vehicle communication: Quo vadis

Abstract: In September 2013, leading experts in intervehicle communication from all over the world met at the renowned Dagstuhl Castle for a seminar discussing the question "Inter-Vehicular Communication - Quo Vadis?" The objective was to identify the current state of the art and, more important, the open challenges in R&D from both a scientific and an industrial point of view. After more than a decade of research on vehicular networks, the experts very seriously asked whether additional research in this field is necessary and, if so, which will be the most intriguing and innovative research directions. It turned out that the overall perspective has changed in the last few years, mainly as a result of the ongoing field operational tests in the United States and Europe. In this article, we report the key outcomes and results from the discussions, pointing to new research directions and new challenges that need to be met for a second generation of vehicular networking applications and protocols. In particular, we present the reports and findings from the four working groups on scientific foundations of vehicular networking, field operational tests, IVC applications, and heterogeneous vehicular networks.

Refined phase diagram of boron nitride

Abstract: The equilibrium phase diagram of boron nitride thermodynamically calculated by Solozhenko in 1988 has been now refined on the basis of new experimental data on BN melting and extrapolation of heat capacities of BN polymorphs into high-temperature region using the adapted pseudo-Debye model As compared with the above diagram, the hBN ⇆ cBN equilibrium line is displaced by 60 K toward higher temperatures The hBN−cBN−L triple point has been calculated to be at 3480 ± 10 K and 59 ± 01 GPa, while the hBN−L−V triple point is at T = 3400 ± 20 K and p = 400 ± 20 Pa, which indicates that the region of thermodynamic stability of vapor in the BN phase diagram is extremely small It has been found that the slope of the cBN melting curve is positive whereas the slope of hBN melting curve varies from positive between ambient pressure and 34 GPa to negative at higher pressures