TY - CHAP
AB - Multiobjective optimization plays an increasingly important role in modern
applications, where several objectives are often of equal importance. The task
in multiobjective optimization and multiobjective optimal control is therefore
to compute the set of optimal compromises (the Pareto set) between the
conflicting objectives. Since the Pareto set generally consists of an infinite
number of solutions, the computational effort can quickly become challenging
which is particularly problematic when the objectives are costly to evaluate as
is the case for models governed by partial differential equations (PDEs). To
decrease the numerical effort to an affordable amount, surrogate models can be
used to replace the expensive PDE evaluations. Existing multiobjective
optimization methods using model reduction are limited either to low parameter
dimensions or to few (ideally two) objectives. In this article, we present a
combination of the reduced basis model reduction method with a continuation
approach using inexact gradients. The resulting approach can handle an
arbitrary number of objectives while yielding a significant reduction in
computing time.
AU - Banholzer, Stefan
AU - Gebken, Bennet
AU - Dellnitz, Michael
AU - Peitz, Sebastian
AU - Volkwein, Stefan
ED - Michael, Hintermüller
ED - Roland, Herzog
ED - Christian, Kanzow
ED - Michael, Ulbrich
ED - Stefan, Ulbrich
ID - 16296
SN - 978-3-030-79392-0
T2 - Non-Smooth and Complementarity-Based Distributed Parameter Systems
TI - ROM-Based Multiobjective Optimization of Elliptic PDEs via Numerical Continuation
ER -
TY - JOUR
AB - While plasmonic particles can provide optical resonances in a wide spectral range from the lower visible up to the near-infrared, often, symmetry effects are utilized to obtain particular optical responses. By breaking certain spatial symmetries, chiral structures arise and provide robust chiroptical responses to these plasmonic resonances. Here, we observe strong chiroptical responses in the linear and nonlinear optical regime for chiral L-handed helicoid-III nanoparticles and quantify them by means of an asymmetric factor, the so-called g-factor. We calculate the linear optical g-factors for two distinct chiroptical resonances to −0.12 and –0.43 and the nonlinear optical g-factors to −1.45 and −1.63. The results demonstrate that the chirality of the helicoid-III nanoparticles is strongly enhanced in the nonlinear regime.
AU - Spreyer, Florian
AU - Mun, Jungho
AU - Kim, Hyeohn
AU - Kim, Ryeong Myeong
AU - Nam, Ki Tae
AU - Rho, Junsuk
AU - Zentgraf, Thomas
ID - 30195
IS - 3
JF - ACS Photonics
KW - Electrical and Electronic Engineering
KW - Atomic and Molecular Physics
KW - and Optics
KW - Biotechnology
KW - Electronic
KW - Optical and Magnetic Materials
SN - 2330-4022
TI - Second Harmonic Optical Circular Dichroism of Plasmonic Chiral Helicoid-III Nanoparticles
VL - 9
ER -
TY - CONF
AB - Resonant evanescent coupling can be utilized to selectively excite orbital angular momentum (OAM) modes of high angular order supported by a thin circular dielectric rod. Our 2.5-D hybrid-analytical coupled mode model combines the vectorial fields associated with the fundamental TE- and TM-modes of a standard silicon photonics slab waveguide, propagating at oblique angles with respect to the rod axis, and the hybrid modes supported by the rod. One observes an efficient resonant interaction in cases where the common axial wavenumber of the waves in the slab matches the propagation constant of one or more modes of the rod. For certain modes of high angular order, the incident wave is able to transfer its directionality to the field in the fiber, exciting effectively only one of a pair of degenerate OAM modes
AU - Hammer, Manfred
AU - Ebers, Lena
AU - Förstner, Jens
ED - Andrews, David L.
ED - Galvez, Enrique J.
ED - Rubinsztein-Dunlop, Halina
ID - 30387
KW - tet_topic_waveguide
T2 - Complex Light and Optical Forces XVI
TI - Resonant evanescent excitation of OAM modes in a high-contrast circular step-index fiber
ER -
TY - CONF
AB - Online solvers for a series of standard 1-D or 2-D problems in integrated optics will be discussed. Implemented on the basis of HTML/JavaScript/SVG with core routines compiled from well tested C++-sources, the quasi-analytical algorithms require a computational load that can be handled easily even by current mobile devices. So far the series covers the 1-D guided modes of dielectric multilayer slab waveguides and the oblique plane wave reflection from these, the modes of rectangular channel waveguides (in an approximation of effective indices), bend modes of curved multilayer slabs, whispering-gallery resonances (“Quasi-Normal-Modes”) supported by circular dielectric cavities, the hybrid modes of circular multi-step-index optical fibers, bound and leaky modes of 1-D complex multilayers, including plasmonic surface modes, and, with restrictions, quite general rectangular scattering problems in 2-D.
AU - Hammer, Manfred
ED - García-Blanco, Sonia M.
ED - Cheben, Pavel
ID - 30389
KW - tet_topic_waveguide
T2 - Integrated Optics: Devices, Materials, and Technologies XXVI
TI - Small-scale online simulations in guided-wave photonics
ER -
TY - JOUR
AB - AbstractMany critical codebases are written in C, and most of them use preprocessor directives to encode variability, effectively encoding software product lines. These preprocessor directives, however, challenge any static code analysis. SPLlift, a previously presented approach for analyzing software product lines, is limited to Java programs that use a rather simple feature encoding and to analysis problems with a finite and ideally small domain. Other approaches that allow the analysis of real-world C software product lines use special-purpose analyses, preventing the reuse of existing analysis infrastructures and ignoring the progress made by the static analysis community. This work presents VarAlyzer, a novel static analysis approach for software product lines. VarAlyzer first transforms preprocessor constructs to plain C while preserving their variability and semantics. It then solves any given distributive analysis problem on transformed product lines in a variability-aware manner. VarAlyzer ’s analysis results are annotated with feature constraints that encode in which configurations each result holds. Our experiments with 95 compilation units of OpenSSL show that applying VarAlyzer enables one to conduct inter-procedural, flow-, field- and context-sensitive data-flow analyses on entire product lines for the first time, outperforming the product-based approach for highly-configurable systems.
AU - Schubert, Philipp
AU - Gazzillo, Paul
AU - Patterson, Zach
AU - Braha, Julian
AU - Schiebel, Fabian
AU - Hermann, Ben
AU - Wei, Shiyi
AU - Bodden, Eric
ID - 30511
IS - 1
JF - Automated Software Engineering
KW - inter-procedural static analysis
KW - software product lines
KW - preprocessor
KW - LLVM
KW - C/C++
SN - 0928-8910
TI - Static data-flow analysis for software product lines in C
VL - 29
ER -
TY - GEN
AU - Schulz, Michael
AU - Neuhaus, Uwe
AU - Kaufmann, Jens
AU - Kühnel, Stephan
AU - Alekozai, Emal M.
AU - Rohde, Heiko
AU - Hoseini, Sayed
AU - Theuerkauf, René
AU - Badura, Daniel
AU - Kerzel, Ulrich
AU - Lanquillon, Carsten
AU - Daurer, Stephan
AU - Günther, Maik
AU - Huber, Lukas
AU - Thiée, Lukas-Walter
AU - zur Heiden, Philipp
AU - Passlick, Jens
AU - Dieckmann, Jonas
AU - Schwade, Florian
AU - Seyffarth, Tobias
AU - Badewitz, Wolfgang
AU - Rissler, Raphael
AU - Sackmann, Stefan
AU - Gölzer, Philipp
AU - Welter, Felix
AU - Röth, Jochen
AU - Seidelmann, Julian
AU - Haneke, Uwe
ID - 30737
TI - DASC-PM v1.1 - Ein Vorgehensmodell für Data-Science-Projekte
ER -
TY - CONF
AB - Within this work, we investigate how data-driven numerical approximation methods of the Koopman operator can be used in practical control engineering applications. We refer to the method Extended Dynamic Mode Decomposition (EDMD), which approximates a nonlinear dynamical system as a linear model. This makes the method ideal for control engineering applications, because a linear system description is often assumed for this purpose. Using academic examples, we simulatively analyze the prediction performance of the learned EDMD models and show how relevant system properties like stability, controllability, and observability are reflected by the EDMD model, which is a critical requirement for a successful control design process. Subsequently, we present our experimental results on a mechatronic test bench and evaluate the applicability to the control engineering design process. As a result, the investigated methods are suitable as a low-effort alternative for the design steps of model building and adaptation in the classical model-based controller design method.
AU - Junker, Annika
AU - Timmermann, Julia
AU - Trächtler, Ansgar
ID - 26389
KW - Koopman Operator
KW - Nonlinear Control
KW - Extended Dynamic Mode Decomposition
KW - Hybrid Modelling
T2 - AIRC'22: 2022 3rd International Conference on Artificial Intelligence, Robotics and Control
TI - Data-Driven Models for Control Engineering Applications Using the Koopman Operator
ER -
TY - JOUR
AB - We study lobby group formation in a two-stage model where the players rst form lobby
groups that then engage in a rent-seeking contest to inuence the legislator. However, the
outcome of the contest aects all players according to the ideological distance between the
implemented policy and the players' preferences. The players can either lobby by themselves,
form a coalition of lobbyists or free ride. We nd that free coalition formation is reasonable
if either players with moderate preferences face lobby groups with extreme preferences, or if
there are two opposing coalitions with an equal number of members. Otherwise, there are
always free riders among the players.
AU - Block, Lukas
ID - 30917
JF - Quick And Easy Journal Title
KW - Group formation
KW - Rent-seeking
KW - Free riding
TI - Coalition formation versus free riding in rent-seeking contests
ER -
TY - JOUR
AU - Reineke Matsudo, Bernhard
AU - Sain, Basudeb
AU - Carletti, Luca
AU - Zhang, Xue
AU - Gao, Wenlong
AU - Angelis, Costantino
AU - Huang, Lingling
AU - Zentgraf, Thomas
ID - 29902
IS - 12
JF - Advanced Science
KW - General Physics and Astronomy
KW - General Engineering
KW - Biochemistry
KW - Genetics and Molecular Biology (miscellaneous)
KW - General Materials Science
KW - General Chemical Engineering
KW - Medicine (miscellaneous)
SN - 2198-3844
TI - Efficient Frequency Conversion with Geometric Phase Control in Optical Metasurfaces
VL - 9
ER -
TY - CHAP
AU - Yigitbas, Enes
AU - Sauer, Stefan
AU - Engels, Gregor
ED - Vogel-Heuser, Birgit
ED - Wimmer, Manuel
ID - 29928
T2 - Digital Transformation: Core Technologies and Emerging Topics from a Computer Science Perspective
TI - Self-Adaptive Digital Assistance Systems for Work 4.0
ER -
TY - JOUR
AU - Gao, Wenlong
AU - Sain, Basudeb
AU - Zentgraf, Thomas
ID - 30964
IS - 4
JF - Physical Review Applied
KW - General Physics and Astronomy
SN - 2331-7019
TI - Spin-Orbit Interaction of Light Enabled by Negative Coupling in High-Quality-Factor Optical Metasurfaces
VL - 17
ER -
TY - JOUR
AB - We study output reference tracking of systems with high relative degree via output feedback only; this is, tracking where the output derivatives are unknown.
To this end, we prove that the conjunction of the funnel pre-compensator with a minimum phase system of arbitrary relative degree yields a system of the same relative degree which is minimum phase as well.
The error between the original system's output and the pre-compensator's output evolves within a prescribed performance funnel; and moreover, the derivatives of the funnel pre-compensator's output are known explicitly.
Therefore, output reference tracking with prescribed transient behavior of the tracking error is possible without knowledge of the derivatives of the original system's output; via funnel control schemes for instance.
AU - Lanza, Lukas Johannes
ID - 23398
JF - Mathematics of Control, Signals, and Systems
TI - Output feedback control with prescribed performance via funnel pre-compensator
ER -
TY - CONF
AB - Classifying nodes in knowledge graphs is an important task, e.g., predicting
missing types of entities, predicting which molecules cause cancer, or
predicting which drugs are promising treatment candidates. While black-box
models often achieve high predictive performance, they are only post-hoc and
locally explainable and do not allow the learned model to be easily enriched
with domain knowledge. Towards this end, learning description logic concepts
from positive and negative examples has been proposed. However, learning such
concepts often takes a long time and state-of-the-art approaches provide
limited support for literal data values, although they are crucial for many
applications. In this paper, we propose EvoLearner - an evolutionary approach
to learn ALCQ(D), which is the attributive language with complement (ALC)
paired with qualified cardinality restrictions (Q) and data properties (D). We
contribute a novel initialization method for the initial population: starting
from positive examples (nodes in the knowledge graph), we perform biased random
walks and translate them to description logic concepts. Moreover, we improve
support for data properties by maximizing information gain when deciding where
to split the data. We show that our approach significantly outperforms the
state of the art on the benchmarking framework SML-Bench for structured machine
learning. Our ablation study confirms that this is due to our novel
initialization method and support for data properties.
AU - Heindorf, Stefan
AU - Blübaum, Lukas
AU - Düsterhus, Nick
AU - Werner, Till
AU - Golani, Varun Nandkumar
AU - Demir, Caglar
AU - Ngonga Ngomo, Axel-Cyrille
ID - 29290
T2 - WWW
TI - EvoLearner: Learning Description Logics with Evolutionary Algorithms
ER -
TY - CONF
AB - The design of control engineering applications usually requires a model that accurately represents the dynamics of the real system. In addition to classical physical modeling, powerful data-driven approaches are increasingly used. However, the resulting models are not necessarily in a form that is advantageous for controller design. In the control engineering domain, it is highly beneficial if the system dynamics is given in PCHD form (Port-Controlled Hamiltonian Systems with Dissipation) because globally stable control laws can be easily realized while physical interpretability is guaranteed. In this work, we exploit the advantages of both strategies and present a new framework to obtain nonlinear high accurate system models in a data-driven way that are directly in PCHD form. We demonstrate the success of our method by model-based application on an academic example, as well as experimentally on a test bed.
AU - Junker, Annika
AU - Timmermann, Julia
AU - Trächtler, Ansgar
ID - 30925
KW - PCHD
KW - passivity
KW - hybrid modeling
KW - system identification
KW - nonlinear control
T2 - 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022)
TI - Learning Data-Driven PCHD Models for Control Engineering Applications
ER -
TY - GEN
AB - In backward error analysis, an approximate solution to an equation is compared to the exact solution to a nearby ‘modified’ equation. In numerical ordinary differential equations, the two agree up to any power of the step size. If the differential equation has a geometric property then the modified equation may share it. In this way, known properties of differential equations can be applied to the approximation. But for partial differential equations, the known modified equations are of higher order, limiting applicability of the theory. Therefore, we study symmetric solutions of discretized
partial differential equations that arise from a discrete variational principle. These symmetric solutions obey infinite-dimensional functional equations. We show that these equations admit second-order modified equations which are Hamiltonian and also possess first-order Lagrangians in modified coordinates. The modified equation and its associated structures are computed explicitly for the case of rotating travelling waves in the nonlinear wave equation.
AU - McLachlan, Robert I
AU - Offen, Christian
ID - 19941
T2 - Journal of Geometric Mechanics
TI - Backward error analysis for variational discretisations of partial differential equations
ER -
TY - THES
AB - Vorgestellt wird ein Entwicklungsforschungsprojekt zur Konzeption und Durchführung einer Veranstaltung "Geometrie für Lehramtsstudierende". Die Schwerpunkte des Projekts sind zum einen die inhaltliche Gestaltung der Veranstaltung und zum anderen die Umsetzung von Professionsorientierung. Bezogen auf den inhaltlichen Aufbau wird das auf metrischen Räumen aufbauende Axiomensystem der "Saccheri-Ebene" vorgestellt und mit alternativen axiomatischen Zugängen zur ebenen Geometrie verglichen. Die Frage nach der Umsetzung von Professionsorientierung in Fachveranstaltungen ist eng mit der Problematik der zweiten Diskontinuität verbunden. In der Arbeit wird dieses Problem auf Grundlage der Synthese von theoretischen Hintergründen zur Bedeutung von mathematischem Wissen und Können für professionelle Handlungskompetenz von Mathematiklehrkräften diskutiert und darauf aufbauend werden theoriebasierte Entwurfsprinzipien für professionsorientierte Fachveranstaltungen entworfen. Zentrale Elemente der methodischen Gestaltung sind die sogenannten "Schnittstellenwochen" zu den Themen Kongruenz und Symmetrie sowie das begleitende Schnittstellen-ePortfolio. Das zentrale Ergebnis der Arbeit ist ein theoretisch fundiertes und empirisch evaluiertes ganzheitliches Veranstaltungskonzept für eine professionsorientierte Geometrie-Veranstaltung für Lehramtsstudierende, dessen Konzeption auf andere Fachveranstaltungen übertragbar ist. Darüber hinaus ergeben sich im Rahmen der durchgeführten Entwicklungsforschung verschiedene neue Beiträge zur Geometriedidaktik in Schule- und Hochschule.
AU - Hoffmann, Max
ID - 31363
TI - Von der Axiomatik bis zur Schnittstellenaufgabe: Entwicklung und Erforschung eines ganzheitlichen Lehrkonzepts für eine Veranstaltung Geometrie für Lehramtsstudierende
ER -
TY - JOUR
AU - Alhaddad, Samer
AU - Förstner, Jens
AU - Groth, Stefan
AU - Grünewald, Daniel
AU - Grynko, Yevgen
AU - Hannig, Frank
AU - Kenter, Tobias
AU - Pfreundt, Franz‐Josef
AU - Plessl, Christian
AU - Schotte, Merlind
AU - Steinke, Thomas
AU - Teich, Jürgen
AU - Weiser, Martin
AU - Wende, Florian
ID - 24788
JF - Concurrency and Computation: Practice and Experience
KW - tet_topic_hpc
SN - 1532-0626
TI - The HighPerMeshes framework for numerical algorithms on unstructured grids
ER -
TY - CHAP
AU - Bauer, Anna
AU - Sacher, Marc
AU - Habig, Sebastian
AU - Fechner, Sabine
ED - Neiske, Iris
ED - Osthushenrich, Judith
ED - Schaper, Niclas
ED - Trier, Ulrike
ED - Vöing, Nerea
ID - 24935
T2 - Hochschule auf Abstand. Ein multiperspektivischer Zugang zur digitalen Lehre
TI - Laborpraktika auf Distanz. Ansätze in den Naturwissenschaften
VL - 3
ER -
TY - JOUR
AU - Woitkowski, David
AU - Rochell, Leonie
AU - Bauer, Anna B.
ID - 24955
JF - Physical Review Physics Education Research
SN - 2469-9896
TI - German university students’ views of nature of science in the introductory phase
ER -
TY - JOUR
AB - While increasing digitalization enables multiple advantages for a reliable operation of technical systems, a remaining challenge in the context of condition monitoring is seen in suitable consideration of uncertainties affecting the monitored system. Therefore, a suitable prognostic approach to predict the remaining useful lifetime of complex technical systems is required. To handle different kinds of uncertainties, a novel Multi-Model-Particle Filtering-based prognostic approach is developed and evaluated by the use case of rubber-metal-elements. These elements are maintained preventively due to the strong influence of uncertainties on their behavior. In this paper, two measurement quantities are compared concerning their ability to establish a prediction of the remaining useful lifetime of the monitored elements and the influence of present uncertainties. Based on three performance indices, the results are evaluated. A comparison with predictions of a classical Particle Filter underlines the superiority of the developed Multi-Model-Particle Filter. Finally, the value of the developed method for enabling condition monitoring of technical systems related to uncertainties is given exemplary by a comparison between the preventive and the predictive maintenance strategy for the use case.
AU - Bender, Amelie
ID - 25046
IS - 10
JF - Machines
KW - prognostics
KW - RUL predictions
KW - particle filter
KW - uncertainty consideration
KW - Multi-Model-Particle Filter
KW - model-based approach
KW - rubber-metal-elements
KW - predictive maintenance
SN - 2075-1702
TI - A Multi-Model-Particle Filtering-Based Prognostic Approach to Consider Uncertainties in RUL Predictions
VL - 9
ER -