TY - GEN AU - Hücker, Lars ID - 50816 TI - Stickstoff basierte Flammschutzmittel für das Lasersintern: Optimierung und Analyse der Recyclingfähigkeit (Studienarbeit) ER - TY - GEN AU - Schulz, Maurice ID - 50815 TI - Phosphorhaltige Lasersinter-Materialien mit Flammschutzwirkung: Optimierung und Analyse der Recyclingfähigkeit (Studienarbeit) ER - TY - CHAP AU - Degeling, Jasmin AU - Haffke, Maren ED - Bee, Julia ED - Gradinari, Irina ED - Köppert , Katrin ID - 50812 T2 - digital:gender - de:mapping affect. Eine spekulative Kartographie TI - Sorgeprakiken der Online-Rechten – Jordan Petersons Therapeutik des ,Self-Authoring' ER - TY - GEN AU - Staffel, Florian Lukas ID - 51624 IS - 2 T2 - Sehepunkte TI - Christian Marx: Wegbereiter der Globalisierung. Multinationale Unternehmen der westeuropäischen Chemieindustrie in der Zeit nach dem Boom (1960er-2000er Jahre) (= Nach dem Boom), Göttingen 2023. VL - 24 ER - TY - JOUR AB - We derive efficient algorithms to compute weakly Pareto optimal solutions for smooth, convex and unconstrained multiobjective optimization problems in general Hilbert spaces. To this end, we define a novel inertial gradient-like dynamical system in the multiobjective setting, which trajectories converge weakly to Pareto optimal solutions. Discretization of this system yields an inertial multiobjective algorithm which generates sequences that converge weakly to Pareto optimal solutions. We employ Nesterov acceleration to define an algorithm with an improved convergence rate compared to the plain multiobjective steepest descent method (Algorithm 1). A further improvement in terms of efficiency is achieved by avoiding the solution of a quadratic subproblem to compute a common step direction for all objective functions, which is usually required in first-order methods. Using a different discretization of our inertial gradient-like dynamical system, we obtain an accelerated multiobjective gradient method that does not require the solution of a subproblem in each step (Algorithm 2). While this algorithm does not converge in general, it yields good results on test problems while being faster than standard steepest descent. AU - Sonntag, Konstantin AU - Peitz, Sebastian ID - 46019 JF - Journal of Optimization Theory and Applications TI - Fast Multiobjective Gradient Methods with Nesterov Acceleration via Inertial Gradient-Like Systems ER - TY - GEN AB - The efficient optimization method for locally Lipschitz continuous multiobjective optimization problems from [1] is extended from finite-dimensional problems to general Hilbert spaces. The method iteratively computes Pareto critical points, where in each iteration, an approximation of the subdifferential is computed in an efficient manner and then used to compute a common descent direction for all objective functions. To prove convergence, we present some new optimality results for nonsmooth multiobjective optimization problems in Hilbert spaces. Using these, we can show that every accumulation point of the sequence generated by our algorithm is Pareto critical under common assumptions. Computational efficiency for finding Pareto critical points is numerically demonstrated for multiobjective optimal control of an obstacle problem. AU - Sonntag, Konstantin AU - Gebken, Bennet AU - Müller, Georg AU - Peitz, Sebastian AU - Volkwein, Stefan ID - 51334 T2 - arXiv:2402.06376 TI - A Descent Method for Nonsmooth Multiobjective Optimization in Hilbert Spaces ER - TY - GEN AU - Bablitzka, Nico Janosch AU - Beimdiek, Janis ID - 51724 TI - Einfluss von Temperatur und Strömungsführung auf die NH3-SCO sowie die NH3-SCR mit Partikeln aus einer Sprayflammensynthese ER - TY - GEN AB - Estimating the infection risks in indoor environments comprises the assessment of the behavior of virus-laden aerosols, i.e. spreading, mixing, removal by air purifiers etc. A promising experimental approach is based on using non-hazardous surrogate aerosols of similar size, e.g. salt particles, to mimic the virus aerosol behavior. This manuscript addresses the issue how a successful transfer of such experiments can be accomplished. Corresponding experiments in two very different environments, a large community hall and a seminar room, with optional use of air purifiers in various constellations were conducted. While high particle concentrations are advantageous in terms of avoiding influence of background aerosol concentrations, it is shown that appropriate consideration of aggregation and settling are vital to theoretically describe the experimentally determined course of particle concentrations. A corresponding model equation for a well-mixed situation is derived and the required parameters are thoroughly determined in separate experiments independently. It is demonstrated that clean air delivery rates (CADR) of air purifiers determined with this approach may differ substantially from common approaches not explicitly taking into account aggregation. AU - Beimdiek, Janis AU - Schmid, Hans-Joachim ID - 51731 KW - surrogate aerosols KW - indoor air cleaners KW - ultra-fine particles KW - COVID-19 KW - test method KW - field experiments: clean air delivery rate T2 - Atmosphere TI - Evaluation of Surrogate Aerosol Experiments to Predict Spreading and Removal of Virus-Laden Aerosols ER - TY - THES AU - Richters, Maximilian ID - 51732 TI - Herstellung und Charakterisierung von Wood-Plastic-Composites (WPC) mit einer Matrix aus thermoplastischen Polyurethanen zur Erzeugung einer Holz-WPC-Verbundstruktur ER - TY - JOUR AU - Schroeter-Wittke, Harald ID - 51733 IS - 1 JF - Praktische Theologie TI - Seven Psalms. Paul Simons theologische Kammermusik VL - 59 ER - TY - JOUR AU - Kullmer, Gunter AU - Weiß, Deborah AU - Schramm, Britta ID - 51737 JF - Engineering Fracture Mechanics KW - Mechanical Engineering KW - Mechanics of Materials KW - General Materials Science SN - 0013-7944 TI - An alternative and robust formulation of the fatigue crack growth rate curve for long cracks VL - 296 ER - TY - CHAP AU - Meyer zu Hörste-Bührer, Raphaela ED - Meyer zu Hörste-Bührer, Raphaela J. ED - Zimmermann, Ruben ED - Erbele-Küster, Dorothea ED - Roth, Michael ED - Volp, Ulrich ID - 51114 T2 - Ethik der Zeit - Zeiten der Ethik TI - Zeit für das Leben - Notwendigkeit und Probleme einer zeitsensiblen Ethik VL - 14 ER - TY - BOOK ED - Meyer zu Hörste-Bührer, Raphaela J. ED - Zimmermann, Ruben ED - Erbele-Küster, Dorothea ED - Roth, Michael ED - Volp, Ulrich ID - 51113 TI - Ethik der Zeit - Zeiten der Ethik VL - 14 ER - TY - CHAP AU - Schulz, Christian ED - Bartelmus, Martin ED - Nebrig, Alexander ID - 51745 T2 - Digitale Schriftlichkeit – Progammieren, Prozessieren und Codieren von Schrift TI - Vernakulärer Code oder die Geister, die der Algorithmus rief - digitale Schriftlichkeit im Kontext von sozialen Medienplattformen ER - TY - CHAP AU - Schulz, Christian ED - Koch, Günter ED - Rottgeri , André ID - 51748 T2 - Populäre Artikulationen – Artikulationen des Populären TI - In Likes We Trust oder die unmögliche Möglichkeit vom Like als Gabe zu sprechen ER - TY - CHAP AU - Schulz, Christian ED - Schürmann, Anja ED - Yacavone, Kathrin ID - 51746 T2 - Die Fotografie und ihre Institutionen. Von der Lehrsammlung zum Bundesinstitut TI - Vom foto-sozialen Graph zum Story-Format: Über die Institutionalisierung sozialmedialer Infrastruktur aus dem Geiste der Fotografie ER - TY - CHAP AU - de Gruisbourne, Birte AU - Schulz, Christian ED - Çiçek, Özgür ED - Savaş, Özlem ID - 51747 T2 - Inquiring healing across screen cultures: Recuperating narratives, mediums, and creativities TI - A Healing Media System of Care - Cancer Diaries and Social Media ER - TY - BOOK ED - Adelmann, Ralf ED - Matzner, Tobias ED - Miggelbrink, Monique ED - Schulz, Christian ID - 51764 TI - Filter – Medienwissenschaftliche Symposien der DFG ER - TY - CHAP AU - Richter, Susanne ED - Kieslinger, Daniel ED - Owsianowski, Judith ID - 51790 SN - 978-3-7841-3666-0 T2 - Inklusiver Kinderschutz – Anforderungen, Herausforderungen, Perspektiven TI - Herausforderungen in der inklusiven Mädchenarbeit: Begleitforschung der „Inklusiven anonymen Zuflucht“ des Mädchenhaus Bielefeld e.V. ER - TY - JOUR AB - We present a convolutional framework which significantly reduces the complexity and thus, the computational effort for distributed reinforcement learning control of dynamical systems governed by partial differential equations (PDEs). Exploiting translational equivariances, the high-dimensional distributed control problem can be transformed into a multi-agent control problem with many identical, uncoupled agents. Furthermore, using the fact that information is transported with finite velocity in many cases, the dimension of the agents’ environment can be drastically reduced using a convolution operation over the state space of the PDE, by which we effectively tackle the curse of dimensionality otherwise present in deep reinforcement learning. In this setting, the complexity can be flexibly adjusted via the kernel width or by using a stride greater than one (meaning that we do not place an actuator at each sensor location). Moreover, scaling from smaller to larger domains – or the transfer between different domains – becomes a straightforward task requiring little effort. We demonstrate the performance of the proposed framework using several PDE examples with increasing complexity, where stabilization is achieved by training a low-dimensional deep deterministic policy gradient agent using minimal computing resources. AU - Peitz, Sebastian AU - Stenner, Jan AU - Chidananda, Vikas AU - Wallscheid, Oliver AU - Brunton, Steven L. AU - Taira, Kunihiko ID - 40171 JF - Physica D: Nonlinear Phenomena TI - Distributed Control of Partial Differential Equations Using Convolutional Reinforcement Learning VL - 461 ER -