Technische Universität Darmstadt

About: Technische Universität Darmstadt is a education organization based out in Darmstadt, Germany. It is known for research contribution in the topics: Neutron & Finite element method. The organization has 17316 authors who have published 40619 publications receiving 937916 citations. The organization is also known as: Darmstadt University of Technology & University of Darmstadt.

Hydrolysis of esters in subcritical and supercritical water

Abstract: The task of this work was to gain a better understanding of the hydrolysis of esters in sub- and supercritical water (SCW). Therefore, the kinetics of the hydrolysis of ethyl acetate as a model reaction was studied in the pressure and temperature range of 23–30 MPa and 250–400°C, respectively. The corresponding reaction mechanisms in sub- and supercritical water were discussed.

Iterative Residual Refinement for Joint Optical Flow and Occlusion Estimation

Abstract: Deep learning approaches to optical flow estimation have seen rapid progress over the recent years. One common trait of many networks is that they refine an initial flow estimate either through multiple stages or across the levels of a coarse-to-fine representation. While leading to more accurate results, the downside of this is an increased number of parameters. Taking inspiration from both classical energy minimization approaches as well as residual networks, we propose an iterative residual refinement (IRR) scheme based on weight sharing that can be combined with several backbone networks. It reduces the number of parameters, improves the accuracy, or even achieves both. Moreover, we show that integrating occlusion prediction and bi-directional flow estimation into our IRR scheme can further boost the accuracy. Our full network achieves state-of-the-art results for both optical flow and occlusion estimation across several standard datasets.

Linear combination of transformations

Abstract: Geometric transformations are most commonly represented as square matrices in computer graphics. Following simple geometric arguments we derive a natural and geometrically meaningful definition of scalar multiples and a commutative addition of transformations based on the matrix representation, given that the matrices have no negative real eigenvalues. Together, these operations allow the linear combination of transformations. This provides the ability to create weighted combination of transformations, interpolate between transformations, and to construct or use arbitrary transformations in a structure similar to a basis of a vector space. These basic techniques are useful for synthesis and analysis of motions or animations. Animations through a set of key transformations are generated using standard techniques such as subdivision curves. For analysis and progressive compression a PCA can be applied to sequences of transformations. We describe an implementation of the techniques that enables an easy-to-use and transparent way of dealing with geometric transformations in graphics software. We compare and relate our approach to other techniques such as matrix decomposition and quaternion interpolation.

Interface of Grafted and Ungrafted Silica Nanoparticles with a Polystyrene Matrix: Atomistic Molecular Dynamics Simulations

Abstract: Atomistic molecular dynamics simulations of a composite consisting of an ungrafted or a grafted spherical silica nanoparticle embedded in a melt of 20-monomer atactic polystyrene chains have been performed. The structural properties of the polymer in the vicinity of a nanoparticle have been studied. The nanoparticle modifies the polymer structure in its neighborhood. These changes increase for higher grafting densities and larger particle diameters. Mass and number density profiles show layering of the polymer chains around the nanoparticle, which extends to ∼2 nm. In contrast, the increase in the polymer’s radius of gyration and other induced ordering (alignment of the chains parallel to the surface and orientation of backbone segments) are shorter-ranged. The infiltration of free polystyrene chains into the grafted chains region is reduced with increasing grafting density. Therefore, the interpenetration of grafted and free chains at high grafting densities, which is responsible for the mechanical ancho...