@inproceedings{65735, author = {{Roberts, Isaac and Kamdem Teyou, Louis Mozart and Schulz, Alexander and Kouagou, N'Dah Jean and Ngonga Ngomo, Axel-Cyrille and Hammer, Barbara}}, booktitle = {{ESANN 2026 proceedings}}, publisher = {{Ciaco - i6doc.com}}, title = {{{A Possible Human-Centered Embedding Space Search in Degenerate Clifford Algebras}}}, doi = {{10.14428/esann/2026.es2026-283}}, year = {{2026}}, } @article{65741, abstract = {{ This work investigates the temperature dependence of the lattice constant a exp of cubic GaN/3C‐SiC/Si (001) epilayers grown at 740°C by plasma‐assisted molecular beam epitaxy is investigated. High resolution X‐ray diffraction is performed to determine the lattice constant, using an Anton–Paar DHS1100 stage to vary the sample temperature from 25°C to 900°C, calibrated against the underlying single‐crystalline silicon substrate. A linear increase in a exp with rising temperature is observed. The thermal expansion behaviour is modelled using Debye´s phonon dispersion. The fitted lattice parameters are used to calculate the thermal expansion coefficient (TEC). At room temperature the TEC is determined to be α Debye  ≈ 5.25 × 10 −6  K −1 . We further compare the TEC of the cubic GaN epilayer to that of free‐standing hexagonal GaN using the crystallographic relationship of , demonstrating good agreement between both phases. Using literature values for the elastic constants of cubic GaN, the corresponding elastic moduli and Debye temperature Θ D are calculated. An average value of Θ D of ≈905 ± 25 K is obtained, which is very close to our experimental results. Moreover, tensile strain is found to be present in our sample at room temperature, leading to an increase in the TEC. The impact of strain on the thermal properties of cubic GaN is discussed. }}, author = {{As, Donat Josef and Meier, Falco and Mahler, Pascal and Meier, Cedrik}}, issn = {{0370-1972}}, journal = {{physica status solidi (b)}}, number = {{2}}, publisher = {{Wiley}}, title = {{{X‐Ray Investigation of the Thermal Expansion Coefficient of Cubic Gallium Nitride on 3C‐SiC (001)/Si (001) Substrates}}}, doi = {{10.1002/pssb.202500477}}, volume = {{263}}, year = {{2026}}, } @article{65745, abstract = {{Abstract In this work, we address the numerical identification of entanglement in dynamical scenarios. To this end, we consider different programs based on the restriction of the evolution to the set of separable (i.e., non-entangled) states, together with the discretization of the space of variables for numerical computations. As a first approach, we apply linear splitting methods to the restricted, continuous equations of motion derived from variational principles. We utilize an exchange interaction Hamiltonian to confirm that the numerical and analytical solutions coincide in the limit of small time steps. The application to different Hamiltonians shows the wide applicability of the method to detect dynamical entanglement. To avoid the derivation of analytical solutions for complex dynamics, we consider variational, numerical integration schemes, introducing a variational discretization for Lagrangians linear in velocities. Here, we examine and compare two approaches: one in which the system is discretized before the restriction is applied, and another in which the restriction precedes the discretization. We find that the "first-discretize-then-restrict" method becomes numerically unstable, already for the example of an exchange-interaction Hamiltonian, which can be an important consideration for the numerical analysis of constrained quantum dynamics. Thereby, broadly applicable numerical tools, including their limitations, for studying entanglement over time are established for assessing the entangling power of processes that are used in quantum information theory.}}, author = {{Offen, Christian and Wembe, Boris and Ares, Laura and Sperling, Jan and Ober-Blöbaum, Sina}}, issn = {{1751-8113}}, journal = {{Journal of Physics A: Mathematical and Theoretical}}, publisher = {{IOP Publishing}}, title = {{{Numerical approaches to entangling dynamics from variational principles}}}, doi = {{10.1088/1751-8121/ae6d51}}, year = {{2026}}, } @article{65742, abstract = {{Abstract In this work, we address the numerical identification of entanglement in dynamical scenarios. To this end, we consider different programs based on the restriction of the evolution to the set of separable (i.e., non-entangled) states, together with the discretization of the space of variables for numerical computations. As a first approach, we apply linear splitting methods to the restricted, continuous equations of motion derived from variational principles. We utilize an exchange interaction Hamiltonian to confirm that the numerical and analytical solutions coincide in the limit of small time steps. The application to different Hamiltonians shows the wide applicability of the method to detect dynamical entanglement. To avoid the derivation of analytical solutions for complex dynamics, we consider variational, numerical integration schemes, introducing a variational discretization for Lagrangians linear in velocities. Here, we examine and compare two approaches: one in which the system is discretized before the restriction is applied, and another in which the restriction precedes the discretization. We find that the "first-discretize-then-restrict" method becomes numerically unstable, already for the example of an exchange-interaction Hamiltonian, which can be an important consideration for the numerical analysis of constrained quantum dynamics. Thereby, broadly applicable numerical tools, including their limitations, for studying entanglement over time are established for assessing the entangling power of processes that are used in quantum information theory.}}, author = {{Offen, Christian and Wembe, Boris and Ares, Laura and Sperling, Jan and Ober-Blöbaum, Sina}}, issn = {{1751-8113}}, journal = {{Journal of Physics A: Mathematical and Theoretical}}, publisher = {{IOP Publishing}}, title = {{{Numerical approaches to entangling dynamics from variational principles}}}, doi = {{10.1088/1751-8121/ae6d51}}, year = {{2026}}, } @inproceedings{65746, abstract = {{This paper presents a class of structure-preserving numerical methods for quantum optimal control problems, based on commutator-free Cayley integrators. Starting from the Krotov framework, we reformulate the forward and backward propagation steps using Cayley-type schemes that preserve unitarity and symmetry at the discrete level. This approach eliminates the need for matrix exponentials and commutators, leading to significant computational savings while maintaining higher-order accuracy. We first recall the standard linear setting and then extend the formulation to nonlinear Schrödinger and Gross-Pitaevskii equations using a Cayley-polynomial interpolation strategy. Numerical experiments on state-transfer problems illustrate that the CF-Cayley method achieves the same accuracy as high-order exponential or Cayley-Magnus schemes at substantially lower cost, especially for longtime or highly oscillatory dynamics. In the nonlinear regime, the structure-preserving properties of the method ensure stability and norm conservation, making it a robust tool for large-scale quantum control simulations. The proposed framework thus bridges geometric integration and optimal control, offering an efficient and reliable alternative to existing exponential-based propagators.}}, author = {{Wembe Moafo, Boris Edgar and Ali, Usman and Meier, Torsten and Ober-Blöbaum, Sina}}, location = {{Reykjavík, Iceland}}, title = {{{Cayley Commutator-free Methods for Krotov-Type Algorithms in Quantum Optimal Control}}}, doi = {{10.48550/ARXIV.2603.11697}}, year = {{2026}}, } @inbook{65702, author = {{Meier, Heiko and Peper, Robert and Kukuk, Marc and Riedl, Lars}}, booktitle = {{Planen. Beteiligen. Bauen. Bewegen. 16. Jahrestagung der dvs-Kommission „Sport und Raum“ vom 19.–20.09.2024 in Bad Driburg & Paderborn}}, editor = {{Meier, Heiko and Kukuk, Marc and Sennefelder, Lisa}}, pages = {{107--121}}, publisher = {{Feldhaus}}, title = {{{Netzwerkanalysen als Bestandteil der Partizipativen Sportentwicklungsplanung}}}, volume = {{Band 305}}, year = {{2026}}, } @unpublished{65744, abstract = {{Optimal control problems with symmetries often admit a non stationary turnpike property called trim turnpike, which characterizes the convergence of optimal solutions to certain symmetry induced trajectories called trim primitives. In this paper we establish an exponential trim turnpike property for a class of optimal control problems with structural properties related to Abelian Lie group symmetries. The key ingredient of our approach is the introduction of an appropriate reduced optimal control problem. We show that extremals of the original problem can be characterized through a reduced Hamiltonian boundary value problem that coincides with the optimality system of the reduced problem. Under a hyperbolicity assumption on the equilibrium of the corresponding reduced Hamiltonian system we prove that optimal trajectories remain exponentially close, up to boundary layers near the endpoints, to a trim primitive defined by the static reduced problem. The theoretical results are illustrated on three representative examples: linear and nonlinear problems with quadratic cost and the Kepler orbital transfer problem.}}, author = {{Maslovskaya, Sofya and Ober-Blöbaum, Sina and Wembe Moafo, Boris Edgar}}, title = {{{Non static exponential turnpike property for optimal control problems with symmetries and boundary conditions}}}, year = {{2026}}, } @article{65747, abstract = {{In this work, we address the numerical identification of entanglement in dynamical scenarios. To this end, we consider different programs based on the restriction of the evolution to the set of separable (i.e., non-entangled) states, together with the discretization of the space of variables for numerical computations. As a first approach, we apply linear splitting methods to the restricted, continuous equations of motion derived from variational principles. We utilize an exchange interaction Hamiltonian to confirm that the numerical and analytical solutions coincide in the limit of small time steps. The application to different Hamiltonians shows the wide applicability of the method to detect dynamical entanglement. To avoid the derivation of analytical solutions for complex dynamics, we consider variational, numerical integration schemes, introducing a variational discretization for Lagrangians linear in velocities. Here, we examine and compare two approaches: one in which the system is discretized before the restriction is applied, and another in which the restriction precedes the discretization. We find that the "first-discretize-then-restrict" method becomes numerically unstable, already for the example of an exchange-interaction Hamiltonian, which can be an important consideration for the numerical analysis of constrained quantum dynamics. Thereby, broadly applicable numerical tools, including their limitations, for studying entanglement over time are established for assessing the entangling power of processes that are used in quantum information theory.}}, author = {{Offen, Christian and Wembe, Boris and Ares, Laura and Sperling, Jan and Ober-Blöbaum, Sina}}, issn = {{1751-8113}}, journal = {{Journal of Physics A: Mathematical and Theoretical}}, publisher = {{IOP Publishing}}, title = {{{Numerical approaches to entangling dynamics from variational principles}}}, doi = {{10.1088/1751-8121/ae6d51}}, year = {{2026}}, } @inbook{65740, author = {{Brinkmann, FRank Thomas and Jacke, Christoph}}, booktitle = {{beRÜHRUNGen. Leibliches, seelisches und existentielles Geschehen in der Popkultur}}, editor = {{Polke, Christian and Seipel, Maria-Louise and Stahl, Mirjam}}, isbn = {{9783658497958}}, issn = {{2569-880X}}, pages = {{45--77}}, publisher = {{Springer Fachmedien Wiesbaden}}, title = {{{Don’t touch me there/Touch my body. Zur Vielstimmigkeit und Unstimmigkeit besungener (Be-)Rührungswünsche}}}, doi = {{10.1007/978-3-658-49796-5}}, year = {{2026}}, } @article{65139, author = {{Jabr, Wael and Gutt, Dominik and Neumann, Jürgen and Kundisch, Dennis}}, journal = {{Information Systems and e-Business Management}}, publisher = {{Springer}}, title = {{{Updating at the Expense of Demand? The Case of Platform Apps}}}, doi = {{10.1007/s1025-026-00723-y}}, year = {{2026}}, } @article{65451, author = {{Ksouri-Gerwien, Christoph and Vorbohle, Christian}}, journal = {{Information Systems and e-Business Management}}, title = {{{Business Model Prototyping and Evaluation from an Ecosystem Perspective: An Actor-based Modeling Framework for Using System Dynamics}}}, year = {{2026}}, } @inbook{65749, abstract = {{Abstract Phase noise is one of the most important properties of oscillators that limit the capacity of high-frequency communication systems. In heterodyne conversion schemes, the phase noise of the local oscillator will be multiplied and up-converted to the transmission channel. Therefore, accurate characterization of the oscillators is highly important for the design of THz communication systems. Especially when it comes to the characterization of high-quality oscillators with extremely low phase noise, traceable measurement methods are not available. In this chapter, the mathematical model and definition of the amplitude noise (AM noise) and phase noise (PM noise) are given. Different phase noise definition standards such as single sideband (SSB) and double sideband will also be provided. Phase noise measurement techniques such as frequency discrimination and phase-locked loop (PLL) technique will be discussed. The standard two-channel cross correlation for statistical analysis of phase noise at levels below the detection limit of the phase noise receiver will be explained with mathematical formalism.}}, author = {{Bahmanian, Meysam and Scheytt, J. Christoph and Meyne, Nora and Kleine-Ostmann, Thomas}}, booktitle = {{Springer Series in Optical Sciences}}, isbn = {{9783032019851}}, issn = {{0342-4111}}, publisher = {{Springer Nature Switzerland}}, title = {{{Phase Noise Metrology}}}, doi = {{10.1007/978-3-032-01986-8_4}}, year = {{2026}}, } @article{65754, abstract = {{ABSTRACT The integration of heat pumps offers a promising route for electrifying chemical processes and reducing CO 2 emissions. Their feasibility strongly depends on the temperature levels and the quantities of available heat sources and sinks, which can be influenced by adjusting process operating parameters to enhance integration potential. The number and quality of these sources and sinks also determine suitable heat pump configurations and therefore the technical and economic viability of implementation. In addition, refrigerant selection is a critical factor, as it is restricted by regulations such as the F‐Gas Regulation. This study investigates how different operating parameters affect the integration potential of various heat pump configurations in a CO 2 absorption process using MEA as solvent. Furthermore, economic evaluations are carried out considering different electricity price scenarios and allowable refrigerants. }}, author = {{Wloch, Johannes and Grünewald, Marcus and Riese, Julia}}, issn = {{0009-286X}}, journal = {{Chemie Ingenieur Technik}}, publisher = {{Wiley}}, title = {{{Matching Heat Pump Configurations and Process Parameters for Cost‐Minimal Heat‐Integrated CO2-Capturing Process}}}, doi = {{10.1002/cite.70131}}, year = {{2026}}, } @inbook{65748, abstract = {{Abstract In this chapter, the precision of optical clocks based on mode-locked laser (MLL) is compared with more conventional types of clock sources. It is shown that the phase noise of the optical pulse train from the MLL can be better than other types of clock sources by orders of magnitude. Then, an abstract representation of frequency synthesizer is demonstrated. Different techniques for RF generation using MLL are shown, and their pros and cons are discussed. Finally, a comparison of all these techniques is made with respect to their phase noise and capability to generate RF signal with different frequencies for different applications.}}, author = {{Bahmanian, Meysam and Scheytt, J. Christoph}}, booktitle = {{Springer Series in Optical Sciences}}, isbn = {{9783032019851}}, issn = {{0342-4111}}, publisher = {{Springer Nature Switzerland}}, title = {{{Frequency Synthesis Based on MLLs}}}, doi = {{10.1007/978-3-032-01986-8_28}}, year = {{2026}}, } @inbook{65755, author = {{Twardzik, Jan Luca and Humpert, Lynn and Cichon, Gerrit and Dumitrescu, Roman}}, booktitle = {{Lecture Notes in Mechanical Engineering}}, isbn = {{9783032211569}}, issn = {{2195-4356}}, publisher = {{Springer Nature Switzerland}}, title = {{{Knowledge Gaps in Circular Product Development: A Systematic Literature Review of the Manufacturing Industry}}}, doi = {{10.1007/978-3-032-21157-6_39}}, year = {{2026}}, } @inbook{63615, author = {{Meyer-Hamme, Johannes and Hartung, Olaf}}, booktitle = {{Handbuch Praxis des Geschichtsunterrichts}}, editor = {{Barricelli, Michele and Lücke, Martin}}, isbn = {{978-3-7344-1775-7}}, issn = {{1435-7658}}, publisher = {{Wochenschau Verlag}}, title = {{{Historisches Lernen}}}, year = {{2026}}, } @article{65757, abstract = {{Electrifying the heating sector is essential for achieving global climate targets like the Paris Agreement’s 1.5 °C goal. In Germany, where 80 % of household energy goes to space heating and hot water, shifting to low-carbon solutions is crucial. Fossil-fuelled district heating networks can incorporate renewable energy via heat pumps, improving efficiency. Although heat pump design typically favours minimal temperature lifts, higher lifts can be economically viable with low electricity prices and abundant renewables. Adding thermal energy storage boosts operational flexibility. This study explores a flexible heat pump operation incorporating part load behaviour with a thermal energy storage in a German city’s district heating system to minimise costs and carbon dioxide emissions. Using a mixed-integer linear programming model, it examines the impact of temperature adjustments and storage on system efficiency. The results show that the integration of a heat pump in a district heating system reduces operating costs. Compared to a supply without a heat pump, with levelised cost of heating of 9.98 cent/kWhth and a fixed operating mode with costs between 9.96 cent/kWhth and 11.49 cent/kWhth, the flexible use results in lowest costs of 9.85 cent/kWhth, while also reducing overall CO2 emissions. Using a full factorial sensitivity analysis, the levelised cost of heating ranged between 9.15 cent/kWhth in the best case and 10.37 cent/kWhth in the worst case for the selected configuration.}}, author = {{Rahlf, Henning Christoph and Divkovic, Denis and Knorr, Lukas and Schlosser, Florian and Meschede, Henning}}, issn = {{0196-8904}}, journal = {{Energy Conversion and Management}}, keywords = {{Heat transition, Optimisation, Temperature flexibility, Decarbonisation, Multi energy}}, publisher = {{Elsevier BV}}, title = {{{Flexible operation strategies for heat pumps in district heating systems using dynamic electricity prices}}}, doi = {{10.1016/j.enconman.2026.121714}}, volume = {{364}}, year = {{2026}}, } @article{63838, abstract = {{Industrial electrification is increasing to reduce fossil fuel dependence, alongside a growing share of volatile renewables. A secure and reliable energy supply is crucial for industry, leading to a shift from centralised to decentralised grid structures. DC microgrids becoming increasingly popular in industry, since they enable energy recuperation from braking, reduce components and cables, and integrate storage and local generation to manage supply interruptions or peak loads. EVs add further synergies by serving as mobile storage units, helping to store and redistribute locally generated renewable energy. This paper analyses how EV integration in droop-controlled DC grids can contribute to a more stable, low-emission and peak-reduced load profile to the supply grid through load shifting and bridge interruptions. A droop-controlled DC grid model has been developed, incorporating an EV charging park based on probability functions. Scalable scenarios allow for diverse condition analysis using an energy management system that utilises fuzzy logic and sequential MILP optimisation. It has been shown that a 7% improvement of coefficient represented grid-serving behaviour is possible by load shifting. It has also been demonstrated that an optimised EMS can reduce the demand-based CO2 emissions by 41kg for a representative day compared to a fuzzy logic EMS. At the same time peak load is decreased yielding a more constant residual load. These results highlight the potential of a controlled bidirectional charging infrastructure in DC grids and underscore the need to explicitly consider charging processes to ensure a residual load as constant as possible.}}, author = {{Rahlf, Henning Christoph and Knorr, Lukas and Althoff, Simon and Meschede, Henning}}, issn = {{2666-9552}}, journal = {{Smart Energy}}, keywords = {{DC-grid, Droop control, Grid-serving behaviour, Grid stability, Bidirectional charging, Sequential decision, MILP optimisation}}, publisher = {{Elsevier BV}}, title = {{{Analysis of bidirectional EV charging infrastructures within industrial DC grids}}}, doi = {{10.1016/j.segy.2026.100227}}, year = {{2026}}, } @inproceedings{65756, author = {{Hellweg, Talea Davina and Sandfort, Luc Dana and Reineke, Malte Fabian and Bartelheimer, Christian and Beverungen, Daniel}}, booktitle = {{European Conference on Information Systems (ECIS) 2026 Proceedings}}, number = {{6}}, title = {{{Temporary Fix Or Process Innovation? A Fuzzy-Set Qualitative Comparative Analysis Of Workarounds}}}, year = {{2026}}, } @inbook{61943, author = {{Bürgel, Christoph and Mertens, Jürgen }}, booktitle = {{Manual of Pedagogical Linguistics}}, editor = {{Pustka, Elisa and Reimann, Daniel}}, title = {{{Foreign Language Professional Communicative Competence as a Component of Language Teachers’ Professional Competence (n.d.).}}}, year = {{2026}}, }