TY - BOOK A1 - Bähr, Martin A1 - Buhl, Johannes A1 - Radow, Georg A1 - Schmidt, Johannes A1 - Bambach, Markus A1 - Breuß, Michael A1 - Fügenschuh, Armin T1 - Stable honeycomb structures and temperature based trajectory optimization for wire-arc additive manufacturing Y1 - 2019 U6 - https://doi.org/10.26127/btuopen-5079 CY - Cottbus ER - TY - RPRT A1 - Beisegel, Jesse A1 - Buhl, Johannes A1 - Izar, Rameez A1 - Schmidt, Johannes A1 - Bambach, Markus A1 - Fügenschuh, Armin ED - Fügenschuh, Armin T1 - Mixed-integer programming for additive manufacturing Y1 - 2021 U6 - https://doi.org/10.26127/BTUOpen-5731 CY - Cottbus ER - TY - BOOK A1 - Schmidt, Johannes A1 - Buhl, Johannes A1 - Fügenschuh, Armin T1 - A finite element approach for trajectory optimization in Wire-Arc Additive Manufacturing Y1 - 2021 U6 - https://doi.org/10.26127/BTUOpen-5575 CY - Cottbus ER - TY - GEN A1 - Bähr, Martin A1 - Buhl, Johannes A1 - Radow, Georg A1 - Schmidt, Johannes A1 - Bambach, Markus A1 - Breuß, Michael A1 - Fügenschuh, Armin T1 - Stable honeycomb structures and temperature based trajectory optimization for wire-arc additive manufacturing T2 - Optimization and Engineering N2 - We consider two mathematical problems that are connected and occur in the layer-wise production process of a workpiece using wire-arc additive manufacturing. As the first task, we consider the automatic construction of a honeycomb structure, given the boundary of a shape of interest. In doing this, we employ Lloyd’s algorithm in two different realizations. For computing the incorporated Voronoi tesselation we consider the use of a Delaunay triangulation or alternatively, the eikonal equation. We compare and modify these approaches with the aim of combining their respective advantages. Then in the second task, to find an optimal tool path guaranteeing minimal production time and high quality of the workpiece, a mixed-integer linear programming problem is derived. The model takes thermal conduction and radiation during the process into account and aims to minimize temperature gradients inside the material. Its solvability for standard mixed-integer solvers is demonstrated on several test-instances. The results are compared with manufactured workpieces. KW - Mixed-integer linear programming KW - Geometric optimization KW - Eikonal equation KW - Heat transmission KW - Additive manufacturing KW - Centroidal Voronoi tesselation Y1 - 2021 U6 - https://doi.org/10.1007/s11081-020-09552-5 SN - 1573-2924 VL - 22 IS - 2 SP - 913 EP - 974 ER - TY - GEN A1 - Bambach, Markus A1 - Fügenschuh, Armin A1 - Buhl, Johannes A1 - Jensch, Felix A1 - Schmidt, Johannes ED - Bambach, Markus T1 - Mathematical Modeling and Optimization for Powder-Based Additive Manufacturing T2 - Procedia Manufacturing; Part of Special issue: 23rd International Conference on Material Forming Y1 - 2020 U6 - https://doi.org/10.1016/j.promfg.2020.04.158 SN - 2351-9789 VL - 47 SP - 1159 EP - 1163 ER - TY - CHAP A1 - Beisegel, Jesse A1 - Buhl, Johannes A1 - Israr, Rameez A1 - Schmidt, Johannes A1 - Bambach, Martin A1 - Fügenschuh, Armin ED - Cristiani, Emiliano ED - Falcone, Maurizio ED - Tozza, Silvia T1 - Mixed-Integer Programming Models for Two Metal Additive Manufacturing Methods T2 - Mathematical Methods for Objects Reconstruction Y1 - 2023 SN - 978-981-9907-75-5 SN - 978-981-9907-76-2 SP - 121 EP - 155 PB - Springer CY - Heidelberg ER - TY - CHAP A1 - Weidner, Silke A1 - Ringel, Johannes A1 - Schmidt, Helga T1 - "time-lapse-photography" in Plagwitz - Ein Stadtteil im Wandel T2 - Der Leipzig Atlas : unterwegs in einer weltoffenen Stadt am Knotenpunkt zwischen West- und Osteuropa Y1 - 2005 SN - 3-89705-269-5 SP - 158 EP - 159 PB - Emons-Verlag CY - Köln ER - TY - GEN A1 - Chun, K. R. Julian A1 - Schmidt, Boris A1 - Kuck, Karl-Heinz A1 - Andresen, Dietrich A1 - Willems, Stefan A1 - Spitzer, Stefan G. A1 - Hoffmann, Ellen A1 - Schumacher, Burghard A1 - Eckardt, Lars A1 - Seidl, Karlheinz A1 - Jünger, Claus A1 - Horack, Martin A1 - Brachmann, Johannes A1 - Senges, Jochen T1 - Catheter ablation of atrial fibrillation in the young T2 - Clinical Research in Cardiology Y1 - 2013 U6 - https://doi.org/10.1007/s00392-013-0553-6 SN - 1861-0684 SN - 1861-0692 VL - 102 IS - 6 SP - 459 EP - 468 ER - TY - GEN A1 - Bleicher, Achim A1 - Schauer, Thomas A1 - Jirasek, Robert A1 - Höltke, Tim A1 - Zhang, Yangwen A1 - Marker, Paul A1 - Wulff, Wulf A1 - Manfrecola, Johannes A1 - Schmidt, Therese T1 - Hybride Konstruktionen an der BTU Cottbus-Senftenberg T2 - Bautechnik N2 - Die angestrebten Ziele einer Ressourcen- und Klimaneutralität erfordern ein radikaleres Umdenken der Bauschaffenden, das mit einer noch viel stärkeren Sensibilisierung der Auftraggeber für die Auswirkungen des Material- und Energieverbrauchs im Bausektor verbunden ist. Ein Ansatz, um diese Ziele zu erreichen, sind hybride Konstruktionen, in denen unterschiedliche Materialien, Elemente, Funktionen und Technologien auf mehreren Konstruktionsebenen ressourcen- und energieeffizient kombiniert sowie im Fall eines Rückbaus sortenrein rezykliert werden. Dieser anspruchsvolle Ansatz ist von Beginn an erklärtes Ziel des Lehrstuhls Hybride Konstruktionen – Massivbau an der BTU Cottbus-Senftenberg und zieht sich durch alle Lehr- und Forschungsaktivitäten. Mit ausgewählten Forschungsprojekten werden Motivation und Methoden hybrider Konstruktionen sowie deren Potenzial für ressourcen- und klimaneutrale Konstruktionen anhand von Prototypen aufgezeigt. Hierbei steht neben der ökologischen Weiterentwicklung klassischer hybrider Konstruktionen aus nachwachsenden und rezyklierten Rohstoffen, bspw. Holz und Recyclingbeton, auch die Entwicklung aktiver hybrider Konstruktionen im Fokus. Die gezielte Integration von aktiven Technologien wie Sensorik, Aktuatorik und Regelungstechnik ermöglicht multifunktionale Konstruktionen, einen hohen Nutzungskomfort, einen geringeren Rohstoffverbrauch bis hin zur Energiegewinnung aus dynamischen Einwirkungen. Y1 - 2021 UR - https://onlinelibrary.wiley.com/doi/abs/10.1002/bate.202100056 U6 - https://doi.org/10.1002/bate.202100056 SN - 1437-0999 VL - 98 IS - 12 SP - 907 EP - 920 ER - TY - GEN A1 - Schmidt, Johannes A1 - Fügenschuh, Armin ED - Grothe, Oliver ED - Nickel, Stefan ED - Rebennack, Steffen ED - Stein, Oliver T1 - Temperature-Based Trajectory Planning for Surfaces in Wire- Arc Additive Manufacturing T2 - Operations Research Proceedings 2022 : Selected Papers of the Annual International Conference of the German Operations Research Society (GOR), Karlsruhe, Germany, September 6-9, 2022 Y1 - 2023 SN - 978-3-031-24906-8 SN - 978-3-031-24907-5 SP - 539 EP - 545 PB - Springer CY - Heidelberg ER - TY - RPRT A1 - Schmidt, Johannes A1 - Fügenschuh, Armin T1 - Trajectory Optimization for Arbitrary Layered Geometries in Wire-Arc Additive Manufacturing Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus4-62678 CY - Cottbus ; Senftenberg ER - TY - GEN A1 - Schmidt, Johannes A1 - Fügenschuh, Armin T1 - A two-time-level model for mission and flight planning of an inhomogeneous fleet of unmanned aerial vehicles T2 - Computational Optimization and Applications Y1 - 2023 U6 - https://doi.org/10.1007/s10589-023-00450-x SN - 1573-2894 SN - 1389-4420 VL - 85 IS - 1 SP - 293 EP - 335 ER - TY - GEN A1 - Böhler, Stefan A1 - Rosencrantz, Sophia A1 - Wolf, Karina A1 - Heinemann, Robert A1 - Schmidt, Peer A1 - Ganster, Johannes A1 - Büsse, Thomas A1 - Balko, Jens A1 - Rosencrantz, Ruben R. T1 - Active protease formulation in commodity polymers withstands melt processing into compounds and blown films T2 - Materials Today Communications N2 - Integrating enzymes into thermoplastic polymers is challenging due to their lack of robustness with respect to temperature and shear fields during conventional melt processing. In the present study, blown films from low-density polyethylene (LDPE) were prepared containing a technical protease from Bacillus sp. First, LDPE/protease compounds were produced followed by blown film extrusion, both processes at melt mass temperatures of 130 °C or higher. Enzyme activity was proven, both for the LDPE/protease compound and the blown film. The highest enzyme activity in the compound was determined for processing at 132 °C and a screw speed of 75 rpm. The influence of melt temperature and shear fields was studied in detail. Enzyme activities were determined for melt temperatures up to 160 °C and for screw speeds ranging from 75 to 300 rpm during compounding by twin-screw extrusion. The process was also applied for biobased and biodegradable polyesters, where similar protease activity after compounding was verified. Electron microscopy, X-ray diffraction, nuclear magnetic resonance spectroscopy and differential scanning calorimetry served to analyze components and morphology of the enzyme formulation used here. It is proposed that the porous morphology of the protease particles is beneficial for the enzyme to remain active after processing. Additionally, the polymer matrix surrounding the particles protects the protease at elevated temperatures, which can be attributed to thermal insulation. Thus, the right combination of a suited technical enzyme formulation with appropriate mild melt compounding conditions allows enzymes to be incorporated into thermoplastics and retain their activity. This opens the way to use the abundant biological functions of enzymes in thermoplastic applications. KW - Thermal analysis KW - X-ray diffraction KW - Crystal structure Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S2352492822018591 U6 - https://doi.org/10.1016/j.mtcomm.2022.105018 SN - 2352-4928 VL - 34 SP - 1 EP - 9 ER - TY - CHAP A1 - Fügenschuh, Armin A1 - Marahrens, Sönke A1 - Johannsmann, Leonie M. A1 - Matuszewski, Sandra A1 - Müllenstedt, Daniel A1 - Schmidt, Johannes ED - Turnitsa, Charles ED - Blais, Curtis Blais ED - Tolk, Andreas T1 - Using Computer-Generated Virtual Realities, Operations Research, and Board Games for Conflict Simulations T2 - Simulation and Wargaming Y1 - 2022 SN - 978-1-119-60478-5 SN - 978-1-119-60479-2 U6 - https://doi.org/10.1002/9781119604815 SP - 273 EP - 287 PB - John Wiley & Sons, Inc. CY - Hoboken, NJ ER - TY - BOOK A1 - Schmidt, Johannes A1 - Fügenschuh, Armin T1 - Planning inspection flights with an inhomogeneous fleet of micro aerial vehicles Y1 - 2021 U6 - https://doi.org/10.26127/BTUOpen-5656 CY - Cottbus ER - TY - BOOK A1 - Schmidt, Johannes A1 - Fügenschuh, Armin T1 - A two-time-level model for mission and flight planning of an inhomogeneous fleet of unmanned aerial vehicles Y1 - 2021 U6 - https://doi.org/10.26127/BTUOpen-5461 CY - Cottbus ER - TY - RPRT A1 - Fügenschuh, Armin A1 - Müllenstedt, Daniel A1 - Schmidt, Johannes T1 - Mission Planning for Unmanned Aerial Vehicles Y1 - 2019 U6 - https://doi.org/10.26127/BTUOpen-4828 SN - 2627-6100 ER - TY - GEN A1 - Schmidt, Johannes A1 - Fügenschuh, Armin T1 - Trajectory optimization for arbitrary layered geometries in wire-arc additive manufacturing T2 - Optimization and Engineering Y1 - 2024 U6 - https://doi.org/10.1007/s11081-023-09813-z SN - 1573-2924 VL - 25 SP - 529 EP - 553 ER -