The Faculty of Mathematics and Natural Sciences: Mathematisch-Naturwissenschaftliche Fakultät: Recent submissions
Now showing items 361-380 of 4923
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Molecular dynamics simulations of boron-nitride nanotubes embedded in amorphous Si-B-N
(2005-05)In this article, we examine the elastic properties of boron-nitride nanotubes, which are embedded in amorphous silicon-boron-nitride ceramics. We employ molecular dynamics simulations using the Parrinello-Rahman approach. ... -
Longitudinalstudie zur Besiedlung des Abwassersystem eines Klinikneubaus mit multiresistenten Enterobakterien und Pseudomonaden im Vergleich zur MRE-Besiedlung bei den Patienten
(2024-08-26)Ein relevantes Risiko für den Eintrag gramnegativer Krankheitserreger stellen wasserführende Systeme dar. Dabei lag der Fokus in der Vergangenheit vor allem auf der Trinkwasserinstallation einschließlich der Armaturen und ... -
A molecular dynamics study of the aluminosilicate chains structure in Al-rich calcium silicate hydrated (C-S-H) gels
(2007-11)Calcium silicate hydrated (C-S-H) gel is the principal binding phase of the cement paste and responsible for its strength. It is basically composed of silicate chains held together with CaO layers, where different guest ... -
A molecular dynamics study on the impact of defects and functionalization on the Young modulus of boron-nitride nanotubes
(2007)In this article, we examine the Young modulus of (6, <em>m</em>) boron-nitride nanotubes with vacancy and functionalization defects. We employ molecular dynamics simulations using the Parrinello-Rahman approach. To this ... -
BOSSANOVA: A bond order dissection approach for efficient electronic structure calculations
(2008-01)In this article, we present a new decomposition approach for the eff cient approximate calculation of the electronic structure problem for molecules. It is based on a dimension-wise decomposition of the space the underlying ... -
A molecular dynamics study of cementitious calcium silicate hydrate (C-S-H) gels
(2007-05)In this article we study the polymerization of silicic acids (Si(OH)<sub>4</sub>) in the presence of calcium ions by molecular dynamics simulations. We focus on the formation and structure of cementitious calcium silicate ... -
Principal manifold learning by sparse grids
(2008-04)In this paper we deal with the construction of lower-dimensional manifolds from high-dimensional data which is an important task in data mining, machine learning and statistics. Here, we consider principal manifolds as the ... -
A molecular dynamics study on fullerene–implanted carbon nanotori as electronmagnetic sensing and emitting devices
(2009-10)Open-ended carbon nanotubes have been found to form toroidal structures [17]. These specific structures bear striking resemblance to electrographic coils. Two modes of action can be thought of: Either the metallic conductivity ... -
Tensor product multiscale many-particle spaces with finite-order weights for the electronic Schrödinger equation
(2009-07)In this article we combine the favorable properties of efficient Gaussian type orbitals basis sets, which are applied with good success in conventional electronic structure methods, and tensor product multiscale bases, ... -
The smoothing effect of integration in ℝd and the ANOVA decomposition
(2010-12)This paper studies the ANOVA decomposition of a <em>d</em>-variate function <em>f</em> defined on the whole of ℝ<em><sup>d</sup></em>, where <em>f</em> is the maximum of a smooth function and zero (or <em>f</em> could ... -
Intraday foreign exchange rate forecasting using sparse grids
(2010-11)We present a machine learning approach using the sparse grid combination technique for the forecasting of intraday foreign exchange rates. The aim is to learn the impact of trading rules used by technical analysts just ... -
Schwarz type solvers for hp-FEM discretizations of mixed problems
(2011-07)The Stokes problem and linear elasticity problems can be viewed as a mixed variational formulation. These formulations are discretized by means of the <em>hp</em>-version of the finite element method. The system of linear ... -
Inexact additive Schwarz solvers for hp-FEM discretizations in three dimensions
(2011-07)In this paper, a boundary value problem of second order in three space dimensions is discretized by means of the <em>hp</em>-version of the finite element method. The system of linear algebraic equations is solved by the ... -
Solving incompressible two-phase flows on multi-GPU clusters
(2011-10)We present a fully multi-GPU-based double-precision solver for the three-dimensional two-phase incompressible Navier-Stokes equations. It is able to simulate the interaction of two fluids like air and water based on a ... -
Fast approximation of the discrete Gauss transform in higher dimensions
(2011-10)We present a novel approach for the fast approximation of the discrete Gauss transform in higher dimensions. The algorithm is based on the dual-tree technique and introduces a new Taylor series expansion. It compares ... -
Approximation of two-variate functions: singular value decomposition versus sparse grids
(2011)We compare the cost complexities of two approximation schemes for functions <em>f</em> ∈ <em>H<sup>p</sup></em>(<em>Ω</em><sub>1</sub> × <em>Ω</em><sub>2</sub>) which live on the product domain <em>Ω</em><sub>1</sub> × ... -
Composition and astringency of Cabernet Sauvignon red wines: Implications of polyphenol-polysaccharide interactions
(2024-08-26)Red wine quality is based on organoleptic properties like color, color stability, and mouthfeel, among others. The specifications for these attributes vary depending on cultivar, wine style, and personal taste. Ideally, ... -
How to Sell Online (Fast) via Pricing-Based Algorithms
(2024-08-23)Online resource allocation problems play a fundamental role in online decision making. In these problems, a sequence of agents arrives one-by-one, each with the goal of being assigned a subset of available items. An ... -
Vehicle Routing in Theory and Practice
(2024-08-23)In this thesis, we study combinatorial optimization problems that arise in logistics and can be summarized under the name vehicle routing. We tackle these problems from two different points of view. First, we study their ... -
Knowledge Graph Creation for Volunteered Geographic Information
(2024-08-23)Community-created geographic data sources, such as OpenStreetMap, are semi-structured sources of geographic information. These sources rely on voluntary contributions from individuals worldwide, resulting in huge amounts ...
