Diese Arbeit beschäftigt sich mit der Modellierung und effizienten Simulation des elastoplastischen Kontaktproblems mit Hilfe von unstetigen Galerkin Methoden. Zur Bestimmung einer approximativen Lösung dieses Problems im Rahmen der Finiten Elemente Methode werden für die Diskretisierung die SIPG bzw. IIPG Methode in Betracht gezogen und entsprechende biorthogonale Ansatzfunktionen für die duale Variable verwendet. Die Lösung des sich daraus ergebenden Systems mit Ungleichheitsnebenbedingunge...

The radio galaxy 3C 84 is a well-studied source of radio emission and was detected as NGC1275 also in the MeV/TeV regime by gamma-ray detectors like MAGIC and Fermi-LAT. It is still unclear where and how the gamma-ray emission is produced. In this thesis, I will confine possible emission sites and exclude the region near the black hole as the origin of the gamma-ray production. For this aim, I investigate the optical depth of the broad-line region using data published by MAGIC and Fermi-...

This study assesses the performance of a multivariate multi-step charging load prediction approach based on the long short-term memory (LSTM) and commercial charging data. The major contribution of this study is to provide a comparison of load prediction between various types of charging sites. Real charging data from shopping centres, residential, public, and workplace charging sites are gathered. Altogether, the data consists of 50,504 charging events measured at 37 different charging sites...

Structural elements of offshore facilities, e.g., offshore wind turbines, are subject to static and dynamic mechanical and environmental loads, for example, from wind, waves, and corrosive media. Protective coatings such as thermal sprayed ZnAl coatings are often used for protection, mainly against corrosive stresses. The Machine Hammer Peening (MHP) process is an innovative and promising technique for the post-treatment of ZnAl coating systems that helps reducing roughness and porosity and i...

The inconvenient nature of non-ideal charging characteristics is demonstrated from a power system point of view. A new adaptive charging algorithm that accounts for non-ideal charging characteristics is introduced. The proposed algorithm increases the local network capacity utilization rate and reduces charging times. The first unique element of the charging algorithm is exploitation of the measured charging currents instead of ideal or predefined values. The second novelty is the introductio...

Moderne Fahrerassistenzsysteme und autonomes Fahren benötigen eine detaillierte Umgebungserfassung. Neben einer präzisen Beschreibung von Form und Zustand der umgebenen Objekte, ist auch ein immer besseres semantisches Verständnis der Situation erforderlich. Die Anforderungen der funktionalen Sicherheit führen dazu, dass diese oft nur durch Redundanz erreicht werden können. Für Systeme zur semantischen Klassifizierung von Objekten werden heutzutage hauptsächlich optische Sensoren verwendet. ...

The coherent control of a charge carrier spin that is localized in a semiconductor quantum dot and the generation of long-lived states for information storage are of particular interest for quantum information processing. This spin interacts predominantly with the surrounding nuclear spins in the quantum dot, which can be described by the central spin model. The periodic application of circularly polarized laser pulses induces nonequilibrium spin dynamics in the quantum dot, giving rise to va...

This dissertation employs an empirical strategy to investigate the information content of insider trading. The analysis is based on the basic premise that insiders, while possessing private information, trade for many reasons and perform a variety of roles. By identifying information motivated trades (trades outside blackout periods) and examining their interest positive interaction to Corporate Social Responsibility (CSR), we show that legal insider trading contributes to market efficiency a...

Die Technologie der DNA-kodierten Substanzbibliotheken (DELs) hat sich in den letzten Jahren als eine vielversprechende Alternative zum Hochdurchsatz-Screening zur Identifizierung kleiner organischer Moleküle, welche mit pharmazeutisch relevanten, biologischen Zielstrukturen interagieren, etabliert. DELs bestehen aus einer Vielzahl an DNA-kodierten Molekülen, welche gleichzeitig in Affinitäts-basierten Selektionsassays gegenüber einer Zielstruktur getestet und im Anschluss anhand ihrer einzig...

Power system innovation promoted by the smart grid vision provides large opportunities for the development of a sustainable energy supply infrastructure. However, the increase in system complexity arises the need for innovative planning and operation paradigms to guarantee the optimal and secure grid management. Nonetheless, suitable testing approaches are also required to ensure reliability, safety and proper system integration of innovative smart grid solutions and technologies before deplo...

In diesem Beitrag werden die Auswirkungen des Klimaschutz-Sofortprogramms der Partei Bündnis90/Die Grünen im Hinblick auf die gesellschaftlichen Verteilungswirkungen und die Potentiale zur Emissionsminderung bewertet. Aufgrund von Unklarheiten in der Ausgestaltung zahlreicher Maßnahmen ist es prinzipiell unmöglich, die damit in Summe einhergehenden Emissionsminderungen zu quantifizieren. Stattdessen wird sich hier auf diejenigen der großen Mannigfaltigkeit an Maßnahmen kapriziert, die im Prog...

We propose a reproducing kernel Hilbert space approach to estimate the slope in a function-on-function linear regression via penalised least squares, regularized by the thin-plate spline smoothness penalty. In contrast to most of the work on functional linear regression, our main focus is on statistical inference with respect to the sup-norm. This point of view is motivated by the fact that slope (surfaces) with rather different shapes may still be identified as similar when the differen...

The problem of constructing a simultaneous confidence band for the mean function of a locally stationary functional time series {Xi,n(t)}i=1,...n is challenging as these bands can not be built on classical limit theory. On the one hand, for a fixed argument t of the functions Xi,n, the maximum absolute deviation between an estimate and the time dependent regression function exhibits (after appropriate standardization) an extreme value behaviour with a Gumbel distribution in the limit. On...

Microstructural responses to the mechanical load of polymers used in tissue engineering is notably important for qualification at in vivo testing, although insufficiently studied, especially regarding promising polycaprolactone (PCL). For further investigations, electrospun PCL scaffolds with different degrees of fiber alignment were produced, using two discrete relative drum collector velocities. Development and preparation of an adjusted sample geometry enabled in situ tensile testing in sc...

This work pursued two goals. On the one hand new insights in the thermoresponsive behavior of poly(2-alkyl-2-oxazoline) (POx) were gathered by comparing the thermoresponsiveness of POx-hydrogels with the solubility behavior of linear POx. On the other hand, the shape-memory properties of different POx’ and poly(cis-1,4-isoprene)s were investigated in detail. To this end, as an intermediate goal a suited crosslinking method had to be found that is capable of crosslinking different POx indepen...

In der vorliegenden Arbeit wird die Gas-Flüssig-Flüssig-Pfropfenströmung als neues Mikroreaktorkonzept untersucht. Der Fokus liegt dabei auf der Nutzung des Kapillarreaktors für heterogen katalysierte Reaktionen mit in der Pfropfenströmung suspendiertem Katalysator. Zur Erzeugung der dreiphasigen Strömung wurde mit dem doppelten koaxialen Kontaktor ein neues Konzept entwickelt, welches den Strömungsbereich mit ähnlichen Phasenanteilen erschließt und dabei eine regelmäßige Pfropfenstruktur mi...

Within the scope of this contribution, a method for the determination of a strain limit for designing components made of elastomeric polyurethane systems is presented. The knowledge of a material-specific strain limit is essential for the structural-mechanical calculation of plastic components in the context of component design. Compared to a commonly used component design, based on a simplified dimensioning approach taking only linear viscoelastic deformations into account, the strain limit ...

AlCrWxSiN thin films (0 ≤ x ≤ 17.1 at.%) were synthesized by means of a hybrid magnetron sputtering process, merging direct current (DC) as well as tungsten high power impulse magnetron sputtering (HiPIMS) supplies. The influences of increasing the tungsten contents on the structural as well as the friction and wear behavior at room and high temperatures (500 °C) were elaborated. As a reference, a W61.4N38.6 system served to analyze synergetic effects on the oxidation behavior. Increased tung...