@article{62643, author = {{Schwabe, Tobias and Kress, Christian and Kruse, Stephan and Weizel, Maxim and Rhee, Hanjo and Scheytt, J. Christoph}}, journal = {{Journal of Lightwave Technology}}, keywords = {{Integrated circuit modeling, Capacitance, Silicon, Modulation, Adaptation models, Semiconductor device modeling, Bandwidth, Data communication, electrooptical transmitter, equalization, free-carrier-plasma dispersion effect, modelling, optical modulator, phase shifter, silicon photonics}}, number = {{1}}, pages = {{255--270}}, title = {{{Forward-Biased Silicon Phase Shifter Modeling for Electronic-Photonic Co-Simulation and Validation in a 250 nm EPIC BiCMOS Technology}}}, doi = {{10.1109/JLT.2024.3450949}}, volume = {{43}}, year = {{2025}}, } @article{62644, author = {{Schwabe, Tobias and Kress, Christian and Sadiye, Babak and Kruse, Stephan and Scheytt, J. Christoph}}, journal = {{IEEE Access}}, keywords = {{Optical attenuators, Equalizers, Phase shifters, Optical modulation, Electro-optic modulators, Optical amplifiers, Circuits, Silicon photonics, Optical saturation, Integrated circuit modeling, Data communication, equalization, electro-optical transmitter, silicon photonics, phase shifter, optical modulator, free-carrier plasma dispersion effect, driver architectures, biasing schemes}}, pages = {{192433--192450}}, title = {{{Analysis and Design of Forward Biased Silicon Photonics Phase Shifter Equalizer Circuits}}}, doi = {{10.1109/ACCESS.2025.3629385}}, volume = {{13}}, year = {{2025}}, } @article{65007, author = {{Knaup, Felix and Schöppner, Volker}}, journal = {{International Polymer Processing}}, keywords = {{CFD simulation, melting modeling, melting process, polymer extrusion, single-screw extruder}}, title = {{{Improvement of a numerical two-phase simulation model for single-screw plasticizing extruders based on experimental investigations}}}, doi = {{10.1515/ipp-2025-0072}}, year = {{2025}}, } @inproceedings{65005, author = {{Knaup, Felix and Brüning, Florian and Schöppner, Volker}}, booktitle = {{Annual Technical Conference of the Society of Plastics Engineers (ANTEC 2025)}}, keywords = {{Aufschmelzen, Aufschmelzmodellierung, delay zone, extrusion, melting modeling}}, title = {{{Improving an Analytical Model of Melting in Single Screw Extruders considering the Delay Zone Length}}}, year = {{2025}}, } @inproceedings{65006, author = {{Knaup, Felix and Brüning, Florian and Schöppner, Volker}}, booktitle = {{Technomer 2025 29. Fachtagung}}, isbn = {{978-3-939382-17-1}}, keywords = {{Aufschmelzen, Aufschmelzmodellierung, Feststoffbett, melting modeling}}, title = {{{Bestimmung der Feststoffbettfestigkeit zur Vorhersage von Feststoffbettbrüchen im Einschneckenextruder}}}, year = {{2025}}, } @article{52218, author = {{Lenz, Peter and Mahnken, Rolf}}, issn = {{0020-7683}}, journal = {{International Journal of Solids and Structures}}, keywords = {{Applied Mathematics, Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science, Modeling and Simulation}}, publisher = {{Elsevier BV}}, title = {{{Multiscale simulation of polymer curing of composites combined mean-field homogenisation methods at large strains}}}, doi = {{10.1016/j.ijsolstr.2023.112642}}, volume = {{290}}, year = {{2024}}, } @inbook{55662, abstract = {{Schneijderberg und Steinhardt zeichnen in diesem Beitrag nach, wie Akkreditierung als sanftes Konditionalprogramm in Bezug auf Diversity-Dimensionen gewirkt hat. Unter sanfter Konditionierung wird in Anlehnung an Luhmann die politische Steuerung durch Akkreditierungskriterien verstanden, die als Vehikel genutzt werden, um gesellschaftlich aktuell diskutierte Themen in den Hochschulen zu platzieren. Der Beitrag rekonstruiert in einem ersten Schritt, wie und welche Diversity-Dimensionen in Akkreditierungskriterien abgebildet wurden. Hierzu wurden die Hochschulrahmengesetze, die ländergemeinsamen Strukturvorgaben der Kultusministerkonferenz, die Akkreditierungskriterien sowie Tätigkeitsberichte und Protokolle des Akkreditierungsrates mittels einer Dokumentenanalyse ausgewertet. Um die Konditionierung nachzuzeichnen, wurde in einem zweiten Schritt eine Topic-Modeling-Analyse von 828 Selbstdokumentationen der Hochschulen, 743 Gutachtenberichte und 560 Beschlussbriefen durchgeführt.}}, author = {{Schneijderberg, Christian and Steinhardt, Isabel}}, booktitle = {{»Die Poesie der Reformen«. Zur Karriere des Diversity Management an Hochschulen in Deutschland}}, editor = {{Griem, Julika and Kaldewey, David and Il-Tschung, Lim}}, isbn = {{9783837666793}}, issn = {{2699-7681}}, keywords = {{Akkreditierung, Diversität, Topic Modeling}}, pages = {{89--108}}, publisher = {{transcript Verlag}}, title = {{{Kleine Strukturmacht statt großer Ideologie. Akkreditierung und Diversity}}}, doi = {{10.14361/9783839466797-006}}, year = {{2024}}, } @article{59243, abstract = {{Most single-screw extruders used in the plastics processing industry are plasticizing extruders, designed to melt solid pellets or powders within the screw channel during processing. In many cases, the efficiency of the melting process acts as the primary throughput-limiting factor. If the material melts too late in the process, it may not be sufficiently mixed, resulting in substandard product quality. Accurate prediction of the melting process is therefore essential for efficient and cost-effective machine design. A practical method for engineers is the modeling of the melting process using mathematical–physical models that can be solved without complex numerical methods. These models enable rapid calculations while still providing sufficient predictive accuracy. This study revisits the modified Tadmor model by Potente, which describes the melting process and predicts the delay-zone length, extending from the hopper front edge to the point of melt pool formation. Based on extensive experimental investigations, this model is adapted by redefining the flow temperatures at the phase boundary and accounting for surface porosity at the beginning of the melting zone. Additionally, the effect of variable solid bed dynamics on model accuracy is examined. Significant model improvements were achieved by accounting for reduced heat flow into the solid bed due to the porous surface structure in the solid conveying zone, along with a new assumption for the flow temperature at the phase boundary between the solid bed and melt film.}}, author = {{Schöppner, Volker and Brüning, Florian and Knaup, Felix}}, journal = {{Polymers}}, keywords = {{delay zone, extrusion, melting modeling}}, number = {{22}}, pages = {{3130}}, title = {{{Improvement in an Analytical Approach for Modeling the Melting Process in Single-Screw Extruders}}}, doi = {{10.3390/polym16223130}}, volume = {{16}}, year = {{2024}}, } @article{47800, abstract = {{The introduction of Systems Engineering is an approach for dealing with the increasing complexity of products and their associated product development. Several introduction strategies are available in the literature; nevertheless, the introduction of Systems Engineering into practice still poses a great challenge to companies. Many companies have already gained experience in the introduction of Systems Engineering. Therefore, as part of the SE4OWL research project, the need to conduct a study including expert interviews and to collect the experiences of experts was identified. A total of 78 hypotheses were identified from 13 expert interviews concerning the lessons learned. Using exclusion criteria, 52 hypotheses were validated in a subsequent quantitative survey with 112 participants. Of these 52 hypotheses, 40 could be confirmed based on the survey results. Only four hypotheses were rejected, and eight could neither be confirmed nor rejected. Through this research, guidance is provided to companies to leverage best practices for the introduction of their own Systems Engineering and to avoid the poor practices of other companies.}}, author = {{Wilke, Daria and Grothe, Robin and Bretz, Lukas and Anacker, Harald and Dumitrescu, Roman}}, issn = {{2079-8954}}, journal = {{Systems}}, keywords = {{Information Systems and Management, Computer Networks and Communications, Modeling and Simulation, Control and Systems Engineering, Software}}, number = {{3}}, publisher = {{MDPI AG}}, title = {{{Lessons Learned from the Introduction of Systems Engineering}}}, doi = {{10.3390/systems11030119}}, volume = {{11}}, year = {{2023}}, } @article{48673, author = {{Lenz, Peter and Kreutzheide, Phil and Mahnken, Rolf}}, issn = {{0045-7949}}, journal = {{Computers & Structures}}, keywords = {{Computer Science Applications, Mechanical Engineering, General Materials Science, Modeling and Simulation, Civil and Structural Engineering}}, publisher = {{Elsevier BV}}, title = {{{Multiphase elasto-plastic mean-field homogenisation and its consistent linearisation}}}, doi = {{10.1016/j.compstruc.2023.107160}}, volume = {{290}}, year = {{2023}}, } @article{53317, author = {{Tao, Youshan and Winkler, Michael}}, issn = {{2163-2480}}, journal = {{Evolution Equations and Control Theory}}, keywords = {{Applied Mathematics, Control and Optimization, Modeling and Simulation}}, number = {{6}}, pages = {{1676--1687}}, publisher = {{American Institute of Mathematical Sciences (AIMS)}}, title = {{{Global smooth solutions in a three-dimensional cross-diffusive SIS epidemic model with saturated taxis at large densities}}}, doi = {{10.3934/eect.2023031}}, volume = {{12}}, year = {{2023}}, } @article{53328, abstract = {{ As a simplified version of a three-component taxis cascade model accounting for different migration strategies of two population groups in search of food, a two-component nonlocal nutrient taxis system is considered in a two-dimensional bounded convex domain with smooth boundary. For any given conveniently regular and biologically meaningful initial data, smallness conditions on the prescribed resource growth and on the initial nutrient signal concentration are identified which ensure the global existence of a global classical solution to the corresponding no-flux initial-boundary value problem. Moreover, under additional assumptions on the food production source these solutions are shown to be bounded, and to stabilize toward semi-trivial equilibria in the large time limit, respectively. }}, author = {{Tao, Youshan and Winkler, Michael}}, issn = {{0218-2025}}, journal = {{Mathematical Models and Methods in Applied Sciences}}, keywords = {{Applied Mathematics, Modeling and Simulation}}, number = {{01}}, pages = {{103--138}}, publisher = {{World Scientific Pub Co Pte Ltd}}, title = {{{Small-signal solutions to a nonlocal cross-diffusion model for interaction of scroungers with rapidly diffusing foragers}}}, doi = {{10.1142/s0218202523500045}}, volume = {{33}}, year = {{2023}}, } @article{44382, abstract = {{The success of engineering complex technical systems is determined by meeting customer requirements and institutional regulations. One example relevant to the automobile industry is the United Nations Economic Commission of Europe (UN ECE), which specifies the homologation of automobile series and requires proof of traceability. The required traceability can be achieved by modeling system artifacts and their relations in a consistent, seamless model—an effect-chain model. Currently, no in-depth methodology exists to support engineers in developing certification-compliant effect-chain models. For this purpose, a new methodology for certification-compliant effect-chain modeling was developed, which includes extensions of an existing method, suitable models, and tools to support engineers in the modeling process. For evaluation purposes, applicability is proven based on the experience of more than 300 workshops at an automotive OEM and an automotive supplier. The following case example is chosen to demonstrate applicability: the development of a window lifter that has to meet the demands of UN ECE Regulations R156 and R21. Results indicate multiple benefits in supporting engineers with the certification-compliant modeling of effect chains. Three benefits are goal-oriented modeling to reduce the necessary modeling capacity, increasing model quality by applying information quality criteria, and the potential to reduce costs through automatable effect-chain analyses for technical changes. Further, companies in the automotive and other industries will benefit from increased modeling capabilities that can be used for architecture modeling and to comply with other regulations such as ASPICE or ISO 26262.}}, author = {{Gräßler, Iris and Wiechel, Dominik and Koch, Anna-Sophie and Sturm, Tim and Markfelder, Thomas}}, issn = {{2079-8954}}, journal = {{Systems}}, keywords = {{Information Systems and Management, Computer Networks and Communications, Modeling and Simulation, Control and Systems Engineering, Software}}, number = {{3}}, publisher = {{MDPI AG}}, title = {{{Methodology for Certification-Compliant Effect-Chain Modeling}}}, doi = {{10.3390/systems11030154}}, volume = {{11}}, year = {{2023}}, } @article{44078, author = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Hengsbach, Florian and Haase, Michael and Tasche, Lennart and Duschik, Kristina and Schaper, Mirko}}, issn = {{0924-0136}}, journal = {{Journal of Materials Processing Technology}}, keywords = {{Industrial and Manufacturing Engineering, Metals and Alloys, Computer Science Applications, Modeling and Simulation, Ceramics and Composites}}, publisher = {{Elsevier BV}}, title = {{{Powder bed fusion of soft-magnetic iron-based alloys with high silicon content}}}, doi = {{10.1016/j.jmatprotec.2023.117991}}, volume = {{317}}, year = {{2023}}, } @article{47065, abstract = {{The reform of the European academic landscape with the introduction of bachelor's and master's degree programs has brought about several profound changes for teaching and assessment in higher education. With regard to the examination system, the shift towards output-oriented teaching is still one of the most significant challenges. Assessments have to be integrated into the teaching and learning arrangements and consistently aligned towards the intended learning outcomes. In particular, assessments should provide valid evidence that learners have acquired competences that are relevant for a specific domain. However, it seems that this didactic goal has not yet been fully achieved in modeling education in computer science. The aim of this study is to investigate whether typical task material used in exercises and exams in modeling education at selected German universities covers relevant competences required for graphical modeling. For this purpose, typical tasks in the field of modeling are first identified by means of a content-analytical procedure. Subsequently, it is determined which competence facets relevant for graphical modeling are addressed by the task types. By contrasting a competence model for modeling with the competences addressed by the tasks, a gap was identified between the required competences and the task material analyzed. In particular, the gap analysis shows the neglect of transversal competence facets as well as those related to the analysis and evaluation of models. The result of this paper is a classification of task types for modeling education and a specification of the competence facets addressed by these tasks. Recommendations for developing and assessing student's competences comprehensively are given.}}, author = {{Soyka, Chantal and Ullrich, Meike and Striewe, Michael and Schaper, Niclas}}, journal = {{Enterprise Modelling and Information Systems Architectures}}, keywords = {{conceptual modeling, higher education, competence-oriented assessment, task analysis, graphical modeling}}, title = {{{Comparison of Required Competences and Task Material in Modeling Education}}}, doi = {{10.18417/EMISA.18.7}}, volume = {{18}}, year = {{2023}}, } @article{48580, abstract = {{Abstract Sandwich packings represent new separation column internals, with a potential to intensify mass transfer. They comprise two conventional structured packings with different specific geometrical surface areas. In this work, the complex fluid dynamics in sandwich packings is modeled using a novel approach based on a one-dimensional, steady momentum balance of the liquid and gas phases. The interactions between the three present phases (gas, liquid, and solid) are considered by closures incorporated into the momentum balance. The formulation of these closures is derived from two fluid-dynamic analogies for the film and froth flow patterns. The adjustable parameters in the closures are regressed for the film flow using dry pressure drop measurements and liquid hold-up data in trickle flow conditions. For the froth flow, the tuning parameters are fitted to overall pressure drop measurements and local liquid hold-up data acquired from ultra-fast X-ray tomography (UFXCT). The model predicts liquid hold-up and pressure drop data with an average relative deviation of 16.4 % and 19 %, respectively. Compared to previous fluid dynamic models for sandwich packings, the number of adjustable parameters could be reduced while maintaining comparable accuracy.}}, author = {{Franke, Patrick and Shabanilemraski, Iman and Schubert, Markus and Hampel, Uwe and Kenig, Eugeny Y.}}, issn = {{1934-2659}}, journal = {{Chemical Product and Process Modeling}}, keywords = {{Modeling and Simulation, General Chemical Engineering}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{A new approach to model the fluid dynamics in sandwich packings}}}, doi = {{10.1515/cppm-2023-0054}}, year = {{2023}}, } @article{31071, abstract = {{Distributed, software-intensive systems (e.g., in the automotive sector) must fulfill communication requirements under hard real-time constraints. The requirements have to be documented and validated carefully using a systematic requirements engineering (RE) approach, for example, by applying scenario-based requirements notations. The resources of the execution platforms and their properties (e.g., CPU frequency or bus throughput) induce effects on the timing behavior, which may lead to violations of the real-time requirements. Nowadays, the platform properties and their induced timing effects are verified against the real-time requirements by means of timing analysis techniques mostly implemented in commercial-off-the-shelf tools. However, such timing analyses are conducted in late development phases since they rely on artifacts produced during these phases (e.g., the platform-specific code). In order to enable early timing analyses already during RE, we extend a scenario-based requirements notation with allocation means to platform models and define operational semantics for the purpose of simulation-based, platform-aware timing analyses. We illustrate and evaluate the approach with an automotive software-intensive system.}}, author = {{Holtmann, Jörg and Deantoni, Julien and Fockel, Markus}}, issn = {{1619-1366}}, journal = {{Software and Systems Modeling}}, keywords = {{Modeling and Simulation, Software}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Early timing analysis based on scenario requirements and platform models}}}, doi = {{10.1007/s10270-022-01002-3}}, year = {{2022}}, } @article{35586, author = {{Protte, Marius and Fahr, Rene and Quevedo, Daniel E.}}, issn = {{1066-033X}}, journal = {{IEEE Control Systems}}, keywords = {{Electrical and Electronic Engineering, Modeling and Simulation, Control and Systems Engineering, Electrical and Electronic Engineering, Modeling and Simulation, Control and Systems Engineering}}, number = {{6}}, pages = {{57--76}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{Behavioral Economics for Human-in-the-Loop Control Systems Design: Overconfidence and the Hot Hand Fallacy}}}, doi = {{10.1109/mcs.2020.3019723}}, volume = {{40}}, year = {{2022}}, } @article{45970, abstract = {{ We introduce a new phase field model for tumor growth where viscoelastic effects are taken into account. The model is derived from basic thermodynamical principles and consists of a convected Cahn–Hilliard equation with source terms for the tumor cells and a convected reaction–diffusion equation with boundary supply for the nutrient. Chemotactic terms, which are essential for the invasive behavior of tumors, are taken into account. The model is completed by a viscoelastic system consisting of the Navier–Stokes equation for the hydrodynamic quantities, and a general constitutive equation with stress relaxation for the left Cauchy–Green tensor associated with the elastic part of the total mechanical response of the viscoelastic material. For a specific choice of the elastic energy density and with an additional dissipative term accounting for stress diffusion, we prove existence of global-in-time weak solutions of the viscoelastic model for tumor growth in two space dimensions [Formula: see text] by the passage to the limit in a fully-discrete finite element scheme where a CFL condition, i.e. [Formula: see text], is required. Moreover, in arbitrary dimensions [Formula: see text], we show stability and existence of solutions for the fully-discrete finite element scheme, where positive definiteness of the discrete Cauchy–Green tensor is proved with a regularization technique that was first introduced by Barrett and Boyaval [Existence and approximation of a (regularized) Oldroyd-B model, Math. Models Methods Appl. Sci. 21 (2011) 1783–1837]. After that, we improve the regularity results in arbitrary dimensions [Formula: see text] and in two dimensions [Formula: see text], where a CFL condition is required. Then, in two dimensions [Formula: see text], we pass to the limit in the discretization parameters and show that subsequences of discrete solutions converge to a global-in-time weak solution. Finally, we present numerical results in two dimensions [Formula: see text]. }}, author = {{Garcke, Harald and Kovács, Balázs and Trautwein, Dennis}}, issn = {{0218-2025}}, journal = {{Mathematical Models and Methods in Applied Sciences}}, keywords = {{Applied Mathematics, Modeling and Simulation}}, number = {{13}}, pages = {{2673--2758}}, publisher = {{World Scientific Pub Co Pte Ltd}}, title = {{{Viscoelastic Cahn–Hilliard models for tumor growth}}}, doi = {{10.1142/s0218202522500634}}, volume = {{32}}, year = {{2022}}, } @article{33839, abstract = {{Modeling is an integral part of many computing-related disciplines and thus also represents a curricular core component in computing education in tertiary education. Competence models in which modeling is integrated at least to some extent already exist in some of these disciplines. However, for the core component of graphical modeling, a competence model that illuminates the relevant competences in detail is still lacking. Therefore, we develop a competence model for graphical modeling with the aim to make teaching and especially assessments in the field more competence-oriented. This paper reports on the first two studies conducted to develop and validate the competence model for graphical modeling. In the first study, the structure of the competence model was developed based on theories and approaches of educational science. Competences relevant for graphical modeling were deductively derived from literature and existing university course descriptions using techniques of qualitative content analysis. The result of the first study is a preliminary competence model. In the second study, the preliminary competence model was reviewed by means of an expert rating in the modeling community. The competence model was revised and refined based on these findings and subsequent expert discussions. The main result of the investigation represents the competence model for graphical modeling (CMGM), which includes a total of 74 competence facets at different cognitive process levels in the five content areas of ”model understanding and interpreting”, ”model building and modifying”, ”values, attitudes, and beliefs”, ”metacognitive knowledge and skills”, and ”social-communicative skills”.}}, author = {{Soyka, Chantal and Schaper, Niclas and Bender, Elena and Striewe, Michael and Ullrich, Meike}}, journal = {{ACM Transactions on Computing Education}}, keywords = {{graphical modeling, conceptual modeling, computer science, competence model, higher education}}, number = {{1}}, publisher = {{Association for Computing Machinery}}, title = {{{Toward a Competence Model for Graphical Modeling}}}, doi = {{10.1145/3567598}}, volume = {{23}}, year = {{2022}}, }