@article{BankOrzadaSmitsetal.2015, author = {Bank, Bart L. van de and Orzada, Stephan and Smits, Frits and Lagemaat, Miriam W. and Rodgers, Christopher T. and Bitz, Andreas and Scheenen, Tom W. J.}, title = {Optimized (31) P MRS in the human brain at 7 T with a dedicated RF coil setup}, series = {NMR in Biomedicine}, volume = {28}, journal = {NMR in Biomedicine}, number = {11}, publisher = {Wiley}, address = {Weinheim}, issn = {1099-1492}, doi = {10.1002/nbm.3422}, pages = {1570 -- 1578}, year = {2015}, language = {en} } @inproceedings{MuellerAltherrLeiseetal.2020, author = {M{\"u}ller, Tim M. and Altherr, Lena and Leise, Philipp and Pelz, Peter F.}, title = {Optimization of pumping systems for buildings: Experimental validation of different degrees of model detail on a modular test rig}, series = {Operations Research Proceedings 2019}, booktitle = {Operations Research Proceedings 2019}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-48438-5}, doi = {10.1007/978-3-030-48439-2_58}, pages = {481 -- 488}, year = {2020}, abstract = {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.}, language = {en} } @article{MuellerLeiseLorenzetal.2020, author = {M{\"u}ller, Tim M. and Leise, Philipp and Lorenz, Imke-Sophie and Altherr, Lena and Pelz, Peter F.}, title = {Optimization and validation of pumping system design and operation for water supply in high-rise buildings}, series = {Optimization and Engineering}, volume = {2021}, journal = {Optimization and Engineering}, number = {22}, publisher = {Springer}, issn = {1573-2924}, doi = {10.1007/s11081-020-09553-4}, pages = {643 -- 686}, year = {2020}, abstract = {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.}, language = {en} } @incollection{AltherrLeisePfetschetal.2021, author = {Altherr, Lena and Leise, Philipp and Pfetsch, Marc E. and Schmitt, Andreas}, title = {Optimal design of resilient technical systems on the example of water supply systems}, series = {Mastering Uncertainty in Mechanical Engineering}, booktitle = {Mastering Uncertainty in Mechanical Engineering}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-78356-3}, pages = {429 -- 433}, year = {2021}, language = {en} } @article{SunAltherrPeietal.2018, author = {Sun, Hui and Altherr, Lena and Pei, Ji and Pelz, Peter F. and Yuan, Shouqi}, title = {Optimal booster station design and operation under uncertain load}, series = {Applied Mechanics and Materials}, volume = {885}, journal = {Applied Mechanics and Materials}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, issn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.885.102}, pages = {102 -- 115}, year = {2018}, abstract = {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}, language = {en} } @article{HagemannUngelenkWiechert1990, author = {Hagemann, Hans-J{\"u}rgen and Ungelenk, J. and Wiechert, D. U.}, title = {Optical time domain reflectometry (OTDR) of diameter modulations in single-mode fibers. Hagemann, H. J.; Ungelenk, J.; Wiechert, D. U.}, series = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 8 (1990), H. 11}, journal = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 8 (1990), H. 11}, isbn = {0733-8724}, pages = {1641 -- 1645}, year = {1990}, language = {en} } @inproceedings{RingbeckSchwarteBuxbaumetal.2001, author = {Ringbeck, Thorsten and Schwarte, Rudolf and Buxbaum, Bernd and Hess, Rudolf}, title = {Optical GMSK modem for infrared wireless communication based on a new receiver principle in CMOS technology}, series = {Optoelectronic interconnects VIII : 25 - 26 January 2001, San Jose, USA. - (Proceedings of SPIE ; 4292)}, booktitle = {Optoelectronic interconnects VIII : 25 - 26 January 2001, San Jose, USA. - (Proceedings of SPIE ; 4292)}, editor = {Tang, Suning}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {0-8194-3970-3}, issn = {0038-7355}, pages = {25 -- 34}, year = {2001}, language = {en} } @article{HagemannGudatKunz1975, author = {Hagemann, Hans-J{\"u}rgen and Gudat, W. and Kunz, C.}, title = {Optical constants from the far infrared to the X-ray region: Mg, Al, Cu, Ag, Au, Bi, C, and Al₂O₃}, series = {Journal of the Optical Society of America (JOSA)}, volume = {65}, journal = {Journal of the Optical Society of America (JOSA)}, number = {6}, publisher = {Optical Society of America}, address = {New York}, isbn = {0030-3941}, doi = {10.1364/JOSA.65.000742}, pages = {742 -- 744}, year = {1975}, language = {en} } @article{OrzadaBitzSchaeferetal.2011, author = {Orzada, Stephan and Bitz, Andreas and Sch{\"a}fer, Lena C. and Ladd, Susanne C. and Ladd, Mark E. and Maderwald, Stefan}, title = {Open design eight-channel transmit/receive coil for high-resolution and real-time ankle imaging at 7 T}, series = {Medical Physics}, volume = {38}, journal = {Medical Physics}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {2473-4209}, doi = {10.1118/1.3553399}, pages = {1162 -- 1167}, year = {2011}, abstract = {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.}, language = {en} } @article{FerreinFritzLakemeyer2004, author = {Ferrein, Alexander and Fritz, Christian and Lakemeyer, Gerhard}, title = {On-Line Decision-Theoretic Golog for Unpredictable Domains / Ferrein, Alexander ; Fritz, Christian ; Lakemeyer, Gerhard}, series = {KI 2004: Advances in Artificial Intelligence : 27th Annual German Conference on AI, KI 2004, Ulm, Germany, September 20-24, 2004. Proceedings}, journal = {KI 2004: Advances in Artificial Intelligence : 27th Annual German Conference on AI, KI 2004, Ulm, Germany, September 20-24, 2004. Proceedings}, publisher = {Springer}, address = {Berlin}, pages = {322 -- 336}, year = {2004}, language = {en} } @article{FerreinSteinbauer2010, author = {Ferrein, Alexander and Steinbauer, Gerald}, title = {On the Way to High-Level Programming for Resource-Limited Embedded Systems with Golog}, series = {Simulation, Modeling, and Programming for Autonomous Robots}, journal = {Simulation, Modeling, and Programming for Autonomous Robots}, pages = {229 -- 240}, year = {2010}, language = {en} } @article{Zastrow1985, author = {Zastrow, Udo}, title = {On the formulation of the fundamental solutions for orthotropic plane elasticity}, series = {Acta Mechanica. 57 (1985), H. 3-4}, journal = {Acta Mechanica. 57 (1985), H. 3-4}, isbn = {1619-6937}, pages = {113 -- 122}, year = {1985}, language = {en} } @article{ZastrowHackl1988, author = {Zastrow, Udo and Hackl, Klaus}, title = {On the existence, uniqueness and completeness of displacements and stress functions in linear elasticity / Hackl, Klaus ; Zastrow, Udo}, series = {Journal of Elasticity. 19 (1988), H. 1}, journal = {Journal of Elasticity. 19 (1988), H. 1}, isbn = {1573-2681}, pages = {3 -- 23}, year = {1988}, language = {en} } @article{HeuermannSadeghfam2007, author = {Heuermann, Holger and Sadeghfam, Arash}, title = {On the design of multimode integrated circuits in multilayered processes / Sadeghfam, A. ; Heuermann, H.}, series = {European Microwave Conference, 2007, 9-12 Oct. 2007}, journal = {European Microwave Conference, 2007, 9-12 Oct. 2007}, isbn = {978-2-87487-001-9}, pages = {516 -- 519}, year = {2007}, language = {en} } @article{Zastrow1985, author = {Zastrow, Udo}, title = {On the complete system of fundamental solutions for anisotropic slices and slabs: A comparison by use of the slab analogy}, series = {Journal of Elasticity. 15 (1985), H. 3}, journal = {Journal of Elasticity. 15 (1985), H. 3}, isbn = {1573-2681}, pages = {293 -- 318}, year = {1985}, language = {en} } @article{AltherrJoggerstLeiseetal.2018, author = {Altherr, Lena and Joggerst, Laura and Leise, Philipp and Pfetsch, Marc E. and Schmitt, Andreas and Wendt, Janine}, title = {On obligations in the development process of resilient systems with algorithmic design methods}, series = {Applied Mechanics and Materials}, volume = {885}, journal = {Applied Mechanics and Materials}, number = {885}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, isbn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.885.240}, pages = {240 -- 252}, year = {2018}, abstract = {Advanced computational methods are needed both for the design of large systems and to compute high accuracy solutions. Such methods are efficient in computation, but the validation of results is very complex, and highly skilled auditors are needed to verify them. We investigate legal questions concerning obligations in the development phase, especially for technical systems developed using advanced methods. In particular, we consider methods of resilient and robust optimization. With these techniques, high performance solutions can be found, despite a high variety of input parameters. However, given the novelty of these methods, it is uncertain whether legal obligations are being met. The aim of this paper is to discuss if and how the choice of a specific computational method affects the developer's product liability. The review of legal obligations in this paper is based on German law and focuses on the requirements that must be met during the design and development process.}, language = {en} } @article{SchubaReichl1998, author = {Schuba, Marko and Reichl, Peter}, title = {On large-scale reliable multicast protocols / Schuba, M. ; Reichl, P.}, series = {6th IEE Conference on Telecommunications}, journal = {6th IEE Conference on Telecommunications}, isbn = {0-85296-700-4}, pages = {133 -- 137}, year = {1998}, language = {en} } @article{BitzZhouElQuardietal.2009, author = {Bitz, Andreas and Zhou, Yi and El Quardi, Abdessamad and Streckert, Joachim}, title = {Occupational Exposure at Mobile Communication Base Station Antenna Sites}, series = {Frequenz}, volume = {63}, journal = {Frequenz}, number = {7-8}, issn = {2191-6349}, doi = {10.1515/FREQ.2009.63.7-8.123}, pages = {123 -- 128}, year = {2009}, language = {en} } @article{SammFaissnerFrenzeletal.1980, author = {Samm, Doris and Faissner, H. and Frenzel, E. and Heinrigs, W.}, title = {Observation of the two-photon decay of a light penetrating particle / H. Faissner, E. Frenzel, W. Heinrigs, A. Preussger, D. Samm und U. Samm}, series = {Physics Letters B. Vol. 103 (1980), H. Issues 3}, journal = {Physics Letters B. Vol. 103 (1980), H. Issues 3}, pages = {234 -- 240}, year = {1980}, language = {en} } @article{Zastrow1985, author = {Zastrow, Udo}, title = {Numerical plane stress analysis by integral equations based on the singularity method}, series = {SM archives . 10 (1985)}, journal = {SM archives . 10 (1985)}, isbn = {0376-7426}, pages = {113 -- 128}, year = {1985}, language = {en} }