TY - JOUR A1 - Engels, Elmar A1 - Doege, E. T1 - Optimizing the number of strokes for punching machines using a fuzzy controlled electrohydraulic damping system / Doege, E. ; Engels, E. JF - ICME 98, CIRP International Seminar on Intelligent Computation in Manufacturing Engineering, Proceedings, Capri, IT, Jul 1-3, 1998 Y1 - 1998 SP - 471 EP - 478 CY - Capri ER - TY - CHAP A1 - Leise, Philipp A1 - Altherr, Lena T1 - Optimizing the design and control of decentralized water supply systems – a case-study of a hotel building T2 - EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization N2 - To increase pressure to supply all floors of high buildings with water, booster stations, normally consisting of several parallel pumps in the basement, are used. In this work, we demonstrate the potential of a decentralized pump topology regarding energy savings in water supply systems of skyscrapers. We present an approach, based on Mixed-Integer Nonlinear Programming, that allows to choose an optimal network topology and optimal pumps from a predefined construction kit comprising different pump types. Using domain-specific scaling laws and Latin Hypercube Sampling, we generate different input sets of pump types and compare their impact on the efficiency and cost of the total system design. As a realistic application example, we consider a hotel building with 325 rooms, 12 floors and up to four pressure zones. KW - Engineering optimization KW - Energy efficiency KW - Water KW - Pump System KW - Latin Hypercube Sampling Y1 - 2018 SN - 978-3-319-97773-7 SN - 978-3-319-97772-0 U6 - http://dx.doi.org/10.1007/978-3-319-97773-7_107 N1 - EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization. 17-19 September 2018. Lisboa, Portugal SP - 1241 EP - 1252 PB - Springer CY - Cham ER - TY - CHAP A1 - Müller, Tim M. A1 - Altherr, Lena A1 - Ahola, Marja A1 - Schabel, Samuel A1 - Pelz, Peter F. T1 - Optimizing pressure screen systems in paper recycling: optimal system layout, component selection and operation N2 - Around 60% of the paper worldwide is made from recovered paper. Especially adhesive contaminants, so called stickies, reduce paper quality. To remove stickies but at the same time keep as many valuable fibers as possible, multi-stage screening systems with several interconnected pressure screens are used. When planning such systems, suitable screens have to be selected and their interconnection as well as operational parameters have to be defined considering multiple conflicting objectives. In this contribution, we present a Mixed-Integer Nonlinear Program to optimize system layout, component selection and operation to find a suitable trade-off between output quality and yield. KW - Mixed-integer nonlinear problem KW - MINLP KW - Process engineering KW - Paper recycling KW - Multi-criteria optimization Y1 - 2018 SN - 978-3-030-18499-5 U6 - http://dx.doi.org/10.1007/978-3-030-18500-8_44 SP - 355 EP - 361 PB - Springer CY - Cham ER - TY - CHAP A1 - Alhwarin, Faraj A1 - Schiffer, Stefan A1 - Ferrein, Alexander A1 - Scholl, Ingrid T1 - Optimized KinectFusion Algorithm for 3D Scanning Applications T2 - Proceedings of the 11th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 2: BIOIMAGING Y1 - 2018 SN - 978-989-758-278-3 U6 - http://dx.doi.org/10.5220/0006594700500057 SP - 50 EP - 57 ER - TY - JOUR A1 - Bank, Bart L. van de A1 - Orzada, Stephan A1 - Smits, Frits A1 - Lagemaat, Miriam W. A1 - Rodgers, Christopher T. A1 - Bitz, Andreas A1 - Scheenen, Tom W. J. T1 - Optimized (31) P MRS in the human brain at 7 T with a dedicated RF coil setup JF - NMR in Biomedicine Y1 - 2015 U6 - http://dx.doi.org/10.1002/nbm.3422 SN - 1099-1492 VL - 28 IS - 11 SP - 1570 EP - 1578 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Müller, Tim M. A1 - Altherr, Lena A1 - Leise, Philipp A1 - Pelz, Peter F. T1 - Optimization of pumping systems for buildings: Experimental validation of different degrees of model detail on a modular test rig T2 - Operations Research Proceedings 2019 N2 - Successful optimization requires an appropriate model of the system under consideration. When selecting a suitable level of detail, one has to consider solution quality as well as the computational and implementation effort. In this paper, we present a MINLP for a pumping system for the drinking water supply of high-rise buildings. We investigate the influence of the granularity of the underlying physical models on the solution quality. Therefore, we model the system with a varying level of detail regarding the friction losses, and conduct an experimental validation of our model on a modular test rig. Furthermore, we investigate the computational effort and show that it can be reduced by the integration of domain-specific knowledge. KW - Experimental validation KW - MINLP KW - Engineering optimization KW - Water supply system KW - Network design Y1 - 2020 SN - 978-3-030-48438-5 U6 - http://dx.doi.org/10.1007/978-3-030-48439-2_58 N1 - Annual International Conference of the German Operations Research Society (GOR), Dresden, Germany, September 4-6, 2019 SP - 481 EP - 488 PB - Springer CY - Cham ER - TY - JOUR A1 - Müller, Tim M. A1 - Leise, Philipp A1 - Lorenz, Imke-Sophie A1 - Altherr, Lena A1 - Pelz, Peter F. T1 - Optimization and validation of pumping system design and operation for water supply in high-rise buildings JF - Optimization and Engineering N2 - The application of mathematical optimization methods for water supply system design and operation provides the capacity to increase the energy efficiency and to lower the investment costs considerably. We present a system approach for the optimal design and operation of pumping systems in real-world high-rise buildings that is based on the usage of mixed-integer nonlinear and mixed-integer linear modeling approaches. In addition, we consider different booster station topologies, i.e. parallel and series-parallel central booster stations as well as decentral booster stations. To confirm the validity of the underlying optimization models with real-world system behavior, we additionally present validation results based on experiments conducted on a modularly constructed pumping test rig. Within the models we consider layout and control decisions for different load scenarios, leading to a Deterministic Equivalent of a two-stage stochastic optimization program. We use a piecewise linearization as well as a piecewise relaxation of the pumps’ characteristics to derive mixed-integer linear models. Besides the solution with off-the-shelf solvers, we present a problem specific exact solving algorithm to improve the computation time. Focusing on the efficient exploration of the solution space, we divide the problem into smaller subproblems, which partly can be cut off in the solution process. Furthermore, we discuss the performance and applicability of the solution approaches for real buildings and analyze the technical aspects of the solutions from an engineer’s point of view, keeping in mind the economically important trade-off between investment and operation costs. KW - Technical Operations Research KW - MINLP KW - MILP KW - Experimental validation KW - Pumping systems Y1 - 2020 U6 - http://dx.doi.org/10.1007/s11081-020-09553-4 SN - 1573-2924 VL - 2021 IS - 22 SP - 643 EP - 686 PB - Springer ER - TY - CHAP A1 - Altherr, Lena A1 - Pelz, Peter F. A1 - Ederer, Thorsten A1 - Pfetsch, Marc E. ED - Jacobs, Georg T1 - Optimale Getriebe auf Knopfdruck: Gemischt-ganzzahlige nichtlineare Optimierung zur Entscheidungsunterstützung bei der Auslegung von Getrieben für Kraftfahrzeuge T2 - Antriebstechnisches Kolloquium ATK 2017 Y1 - 2017 SN - 9783743148970 N1 - Antriebstechnisches Kolloquium ATK 2017, 07.03-08.03.2017. Aachen, Deutschland SP - 313 EP - 325 ER - TY - CHAP A1 - Altherr, Lena A1 - Leise, Philipp A1 - Pfetsch, Marc E. A1 - Schmitt, Andreas T1 - Optimal design of resilient technical systems on the example of water supply systems T2 - Mastering Uncertainty in Mechanical Engineering Y1 - 2021 SN - 978-3-030-78356-3 N1 - Unterkapitel des Kapitels "Strategies for Mastering Uncertainty" SP - 429 EP - 433 PB - Springer CY - Cham ER - TY - JOUR A1 - Sun, Hui A1 - Altherr, Lena A1 - Pei, Ji A1 - Pelz, Peter F. A1 - Yuan, Shouqi T1 - Optimal booster station design and operation under uncertain load JF - Applied Mechanics and Materials N2 - Given industrial applications, the costs for the operation and maintenance of a pump system typically far exceed its purchase price. For finding an optimal pump configuration which minimizes not only investment, but life-cycle costs, methods like Technical Operations Research which is based on Mixed-Integer Programming can be applied. However, during the planning phase, the designer is often faced with uncertain input data, e.g. future load demands can only be estimated. In this work, we deal with this uncertainty by developing a chance-constrained two-stage (CCTS) stochastic program. The design and operation of a booster station working under uncertain load demand are optimized to minimize total cost including purchase price, operation cost incurred by energy consumption and penalty cost resulting from water shortage. We find optimized system layouts using a sample average approximation (SAA) algorithm, and analyze the results for different risk levels of water shortage. By adjusting the risk level, the costs and performance range of the system can be balanced, and thus the system’s resilience can be engineered KW - Stochastic Programming KW - Chance Constraint KW - Engineering Application KW - Pump System KW - Water Distribution Y1 - 2018 U6 - http://dx.doi.org/10.4028/www.scientific.net/AMM.885.102 SN - 1662-7482 VL - 885 SP - 102 EP - 115 PB - Trans Tech Publications CY - Bäch ER - TY - JOUR A1 - Hagemann, Hans-Jürgen A1 - Ungelenk, J. A1 - Wiechert, D. U. T1 - Optical time domain reflectometry (OTDR) of diameter modulations in single-mode fibers. Hagemann, H. J.; Ungelenk, J.; Wiechert, D. U. JF - Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 8 (1990), H. 11 Y1 - 1990 SN - 0733-8724 SP - 1641 EP - 1645 ER - TY - CHAP A1 - Ringbeck, Thorsten A1 - Schwarte, Rudolf A1 - Buxbaum, Bernd A1 - Hess, Rudolf ED - Tang, Suning T1 - Optical GMSK modem for infrared wireless communication based on a new receiver principle in CMOS technology T2 - Optoelectronic interconnects VIII : 25 - 26 January 2001, San Jose, USA. - (Proceedings of SPIE ; 4292) Y1 - 2001 SN - 0-8194-3970-3 SN - 0038-7355 SN - 0361-0748 SN - 0277-786X N1 - Optoelectronic Interconnects <8, 2001, San Jose, Calif.> SP - 25 EP - 34 PB - SPIE CY - Bellingham, Wash. ER - TY - JOUR A1 - Hagemann, Hans-Jürgen A1 - Gudat, W. A1 - Kunz, C. T1 - Optical constants from the far infrared to the X-ray region: Mg, Al, Cu, Ag, Au, Bi, C, and Al₂O₃ JF - Journal of the Optical Society of America (JOSA) Y1 - 1975 SN - 0030-3941 U6 - http://dx.doi.org/10.1364/JOSA.65.000742 VL - 65 IS - 6 SP - 742 EP - 744 PB - Optical Society of America CY - New York ER - TY - JOUR A1 - Orzada, Stephan A1 - Bitz, Andreas A1 - Schäfer, Lena C. A1 - Ladd, Susanne C. A1 - Ladd, Mark E. A1 - Maderwald, Stefan T1 - Open design eight-channel transmit/receive coil for high-resolution and real-time ankle imaging at 7 T JF - Medical Physics N2 - Purpose: At 1.5 T, real-time MRI of joint movement has been shown to be feasible. However, 7 T, provides higher SNR and thus an improved potential for parallel imaging acceleration. The purpose of this work was to build an open, U-shaped eight-channel transmit/receive microstrip coil for 7 T MRI to enable high-resolution and real-time imaging of the moving ankle joint. Methods: A U-shaped eight-channel transmit/receive array for the human ankle was built.urn:x-wiley:00942405:mp3399:equation:mp3399-math-0001-parameters and urn:x-wiley:00942405:mp3399:equation:mp3399-math-0002-factor were measured. SAR calculations of different ankle postures were performed to ensure patient safety. Inhomogeneities in the transmit field consequent to the open design were compensated for by the use of static RF shimming. High-resolution and real-time imaging was performed in human volunteers. Results: The presented array showed good performance with regard to patient comfort and image quality. High acceleration factors of up to 4 are feasible without visible acceleration artifacts. Reasonable image homogeneity was achieved with RF shimming. Conclusions: Open, noncylindrical designs for transmit/receive coils are practical at 7 T and real-time imaging of the moving joint is feasible with the presented coil design. Y1 - 2011 U6 - http://dx.doi.org/10.1118/1.3553399 SN - 2473-4209 VL - 38 IS - 3 SP - 1162 EP - 1167 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Ferrein, Alexander A1 - Fritz, Christian A1 - Lakemeyer, Gerhard T1 - On-Line Decision-Theoretic Golog for Unpredictable Domains / Ferrein, Alexander ; Fritz, Christian ; Lakemeyer, Gerhard JF - KI 2004: Advances in Artificial Intelligence : 27th Annual German Conference on AI, KI 2004, Ulm, Germany, September 20-24, 2004. Proceedings Y1 - 2004 N1 - Lecture Notes in Computer Science ; 3238 SP - 322 EP - 336 PB - Springer CY - Berlin ER - TY - JOUR A1 - Ferrein, Alexander A1 - Steinbauer, Gerald T1 - On the Way to High-Level Programming for Resource-Limited Embedded Systems with Golog JF - Simulation, Modeling, and Programming for Autonomous Robots Y1 - 2010 N1 - Lecture Notes in Computer Science ; 6472 ; Second International Conference, SIMPAR 2010, Darmstadt, Germany, November 15-18, 2010. Proceedings SP - 229 EP - 240 ER - TY - JOUR A1 - Zastrow, Udo T1 - On the formulation of the fundamental solutions for orthotropic plane elasticity JF - Acta Mechanica. 57 (1985), H. 3-4 Y1 - 1985 SN - 1619-6937 SP - 113 EP - 122 ER - TY - JOUR A1 - Zastrow, Udo A1 - Hackl, Klaus T1 - On the existence, uniqueness and completeness of displacements and stress functions in linear elasticity / Hackl, Klaus ; Zastrow, Udo JF - Journal of Elasticity. 19 (1988), H. 1 Y1 - 1988 SN - 1573-2681 SP - 3 EP - 23 ER - TY - JOUR A1 - Heuermann, Holger A1 - Sadeghfam, Arash T1 - On the design of multimode integrated circuits in multilayered processes / Sadeghfam, A. ; Heuermann, H. JF - European Microwave Conference, 2007, 9-12 Oct. 2007 Y1 - 2007 SN - 978-2-87487-001-9 N1 - EuMC 2007 ; European Microwave Conference ; (37 : ; 2007.10.09-12 : ; Munich) SP - 516 EP - 519 ER - TY - JOUR A1 - Zastrow, Udo T1 - On the complete system of fundamental solutions for anisotropic slices and slabs: A comparison by use of the slab analogy JF - Journal of Elasticity. 15 (1985), H. 3 Y1 - 1985 SN - 1573-2681 SP - 293 EP - 318 ER -