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As of today, personalized item suggestions provided by an automated recommender system have become a crucial part of many online services, e.g., online shops or media streaming applications, and extensive evidence exists that such systems increase both the user experience as well as the revenue of the providers. In academia, the recommendation problem is often framed as finding suitable items that a user is not yet aware of based on his long-term preference profile. In the real world, however...
In der vorliegenden Arbeit wird, basierend auf der Finiten-Elemente-Methode, ein numerisches Verfahren zur Lösung von dynamischen, thermomechanisch gekoppelten, elastoplastischen und reibungsbehafteten Kontaktproblemen entwickelt. In dem betrachteten Modellproblem werden die linearisierte Kontaktbedingungen und Verzerrungen verwendet, jedoch wird für die plastische Verzerrung sowohl kinematische als auch isotropische Verfestigung berücksichtigt. Als Reibgrenze werden allgemeine Reibgesetze zu...
Natural Killer (NK) cells act as the front line of the body´s defense in the immune system and they are key players in efficiently recognizing and eliminating virus-infected and tumor cells. Individual NK cells can eliminate multiple target cells in a sequential manner during a process named serial killing. There are two major pathways NK cells use to induce apoptosis in their target cells: By releasing the content of cytotoxic granules containing the serine protease granzyme B (GrzB) and the...
In this work, we present a new approach for coupled CFD-optics problems that consists of a combination of a finite element method (FEM) based flow solver with a ray tracing based tool for optic forces that are induced by a laser. We combined the open-source computational fluid dynamics (CFD) package FEATFLOW with the ray tracing software of the LAT-RUB to simulate optical trap configurations. We benchmark and analyze the solver first based on a configuration with a single spherical particle t...
Nitrogen-vacancy (NV) centers in diamond have become an important tool for quantumtechnologies. All of these applications rely on long coherence times of electron and nuclear spinsassociated with these centers. Here, we study the energy level anti-crossings of an NV center indiamond coupled to a first-shell13C nuclear spin in a small static magnetic field. These levelanti-crossings (LACs) occur for specific orientations of the static magnetic field due to the strongnon-secular components of t...
Large data sets are often stored distributedly to increase the reliability of systems and the efficiency of query evaluation in them. While some query operators -- like selections and projections -- are intrinsically conform with parallel evaluation, others -- like joins -- demand specific distribution patterns. For relational databases, a common approach to evaluate queries in parallel relies on the use of rather simple distribution patterns for binary joins and the computation of the que...
The question about the authentic Christian doctrine lets us experience different answers throughout history. The very problematic emerges though with regard to the ecumenical coexistence and cooperation of different Christian denominations. Not only Christ himself, but also his incarnation in particular, could raise a new perspective for the ecumenical dialogue today. The comprehensive relevance of the Incarnation has shown its central relevance for the Christian doctrine from the ancient tim...
We consider a Gierer-Meinhardt system on a surface coupled with aparabolic PDE in the bulk, the domain confined by this surface. Such a model was recently proposed and analyzed for two-dimensional bulk domains by Gomez, Ward and Wei (SIAM J. Appl. Dyn. Syst. 18, 2019).We prove the well-posedness of the bulk-surface system in arbitrary space dimensions and show that solutions remain uniformly bounded in parabolic Hölder spaces for all times. The proof uses Schauders fixed po...
In modern high-dimensional data sets, feature selection is an essential pre-processing step for many statistical modelling tasks. The field of cost-sensitive feature selection extends the concepts of feature selection by introducing so-called feature costs. These do not necessarily relate to financial costs, but can be seen as a general construct to numerically valuate any disfavored aspect of a feature, like for example the run-time of a measurement procedure, or the patient harm of a biomar...
Excitons are fundamental electronic excitations in a semiconductor. They are bound states consisting of an electron in the conduction band and a positively charged hole in the valence band. They have hydrogen-like properties and are therefore referred to as the hydrogen analogues in solid states. In the semiconductor Cuprous Oxide, Cu2O, highly excited states of excitons can be observed with principal quantum numbers up to n = 25. These states are called Rydberg excitons in analogy to th...
Unter öffentlichen Stakeholdern besteht eine durchaus verbreitete Fehlvorstellung, der Bestätigungsvermerk garantiere eine wirtschaftliche Gesundheit des geprüften Unternehmens, was - jedenfalls de lege lata - mitnichten zutreffend ist. De lege lata ist der Bestätigungsvermerk als zentrales Instrument der externen Unternehmensberichterstattung eher im Sinne eines Formaltestats ausgestaltet, dessen Bedeutungsgehalt sich darin erschöpft, die rechts- und gesetzeskonforme Rechnungslegung im Beric...
In this thesis, two searches for the pair production of vector-like top (VLT) and vector-like bottom (VLB) quarks are presented using 36.1 fb⁻¹ and 139 fb⁻¹ of data. The data was taken at √s = 13 TeV in proton-proton collisions with the ATLAS detector, which is one of the major experiments at the Large Hadron Collider at CERN. The decay signature of this search for TT and BB production is characterized by the presence of a Z-boson, which is reconstructed from two opposite-charge same-flavor l...
Die vorliegende Arbeit wurde im Rahmen einer Industriepromotion bei der Daimler AG in Sindelfingen erstellt. Sie umfasst die Entwicklung und Beschreibung eines statistischen Methodenbaukastens um Last- und Verschleißanalysen prozessual durchführen zu können. Dieser Methodenbaukasten wird an Daten im Kontext alternativer Antriebssysteme beispielhaft erprobt. Der methodische Fokus liegt auf der Quantifizierung und Sensitivität der Güte bzw. Unsicherheit auf den einzelnen Analysestufen. Die erst...