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Propagation and branching strategies for job shop scheduling minimizing the weighted energy consumption
(2023)
We consider a job shop scheduling problem with time windows, flexible energy prices, and machines whose energy consumption depends on their operational state (offline, ramp-up, setup, processing, standby or ramp-down). The goal is to find a valid schedule that minimizes the overall energy cost. To solve this problem to optimality, we developed a branch-and-bound algorithm based on a time-indexed integer linear programming (ILP) formulation, which uses binary variables that describe blocks spanning multiple inactive ...
Konferenzveröffentlichung
Identifying critical demand periods in capacity planning for networks including storage
(2023)
We consider a capacity planning problem for networks including storage. Given a graph and a time series of demands and supplies, we seek for integer link and storage capacities that permit a single commodity flow with valid storage in- and outtakes over all time steps. This problem arises, for example, in power systems planning, where storage can be used to buffer peaks of varying supplies and demands. For typical time series spanning a full year at hourly resolution, this leads to huge optimization models. To reduce ...
Dissertation
Pathogenic Mutations in Catalytic Subunit Isoforms of the cAMP-Dependent Protein Kinase
(2023)
Protein kinase A (PKA) is an integral part in a myriad of cellular pathways and a main effector of the second messenger cAMP. Since its discovery in the late 1960s, PKA has become one of the best-studied eukaryotic protein kinases in terms of enzymatic and structural features. Pathological implications of PKA have just started to emerge. There are three main isoforms (α, β, γ) of the catalytic subunit of PKA (PKA-C) which constitute a holoenzyme (R2C2) by association with a regulatory subunit (PKA-R) dimer. While ...
Dissertation
Asymmetric magnetization reversal processes in exchange-biased microstructures
(2023)
Over the last decades, the exchange bias (EB) effect has captured the attention of the research community striving for high-density logic memory devices and sensitive sensor technologies based on bi-, multilayered, or patterned magnetic thin film systems. Macroscopically, the EB manifests in a horizontal shift of the ferromagnetic remagnetization loop and an enhancement of the coercivity, both connected to the induced unidirectional anisotropy (UDA) at the exchange-coupled ferromagnetic/antiferromagnetic interface. ...
Dissertation
Generation Human Body Motion by the Centralized Networks
(2023)
The main goal of the thesis is to describe and study reduced models for efficient simulations of human body motions (HBM). To this end, we propose new coupled oscillator models, which are networks of dynamically coupled elements. These networks consist of a few of centers and many satellites. The centers evolve in time as periodical oscillators with different frequencies. The satellite states are defined via center states by a radial basis function (RBF) networks. To simulate different motions we adjust the parameter ...
Dissertation
Ultraschnelle kohärente Kontrollmethoden für die nichtlineare Mikroskopie und Spektroskopie
(2023-11-28)
Ultrakurze Laserpulse im Nanojoule-Energiebereich auf der Femto- bis Pikosekunden-Zeitskala ermöglichen die Erzeugung immenser Feldstärken bei Fokussierung auf wenige Quadratmikrometer Fläche. In diesem Szenario wirken starke Kräfte auf die Elektronensysteme von Atomen und Molekülen im Fokus ein, so dass sich die linearen optischen Eigenschaften von Stoffen ändern können – nichtlineare Eigenschaften treten zutage. Mit einem Pulsformer kann auf die breiten Spektren ultrakurzer Laserpulse per spektraler Phasenmodulation ...
Dissertation
On the analysis of path-dependent functionals of stochastic PDEs
(2023)
Weak approximation methods for stochastic partial differential equations (SPDEs) are concerned with approximating the probability distribution of the solution process rather than the realizations of the solution process itself. In this thesis, we provide new results and methods concerning the weak error analysis of numerical approximations of path-dependent functionals of solution processes of SPDEs. Two separate approaches to analyzing weak approximation errors are considered: the Itô calculus approach and the ...
Dissertation
Biochemical Characterization of Microtubule-Associated Serine/Threonine Kinases
(2023)
The association of human microtubule-associated serine/threonine (MAST) kinases with different diseases, such as neurodevelopmental disorders and cancer, leads to hight interest in understanding the function of these understudied kinases. This PhD thesis provides the first consolidated biochemical analysis of three different human MAST kinases (MAST1-3) and the Drosophila melanogaster homologue drop out protein (DOP).
Dissertation
A Unifying Theory for Runge-Kutta-like Time Integrators: Convergence and Stability
(2024)
The work deals with two major topics concerning the numerical analysis of Runge-Kutta-like (RK-like) methods, namely their stability and order of convergence. RK-like methods differ from additive RK methods in that their coefficients are allowed to depend on the solution and the step size. As a result of this, we also refer to them as non-standard additive RK (NSARK) methods. We motivate and introduce modified Patankar (MP) schemes as a subclass of NSARK methods and emphasize their importance. The first major part ...
Dissertation
Immobilization of Neodymium Complexes on Semiconductor Surfaces and Processing of GaAs-based Photonic Crystals
(2024)
Lanthanide ion luminescence exhibits characteristic narrow emission bands ranging from VIS to NIR along with relatively long emission lifetimes which makes them attractive for applications in lighting, sensing, and display technologies. The focus of this dissertation lies on the optical characterization of newly synthesized neodymium complexes bearing phosphonate ester ligands and the fabrication of photonic crystal (PhC) cavities. Micro-photoluminescence (PL) spectroscopy is used to investigate the NIR emission bands ...