TY - JOUR A1 - Altherr, Lena A1 - Leise, Philipp A1 - Pfetsch, Marc E. A1 - Schmitt, Andreas T1 - Algorithmic design and resilience assessment of energy efficient high-rise water supply systems JF - Applied Mechanics and Materials N2 - High-rise water supply systems provide water flow and suitable pressure in all levels of tall buildings. To design such state-of-the-art systems, the consideration of energy efficiency and the anticipation of component failures are mandatory. In this paper, we use Mixed-Integer Nonlinear Programming to compute an optimal placement of pipes and pumps, as well as an optimal control strategy.Moreover, we consider the resilience of the system to pump failures. A resilient system is able to fulfill a predefined minimum functionality even though components fail or are restricted in their normal usage. We present models to measure and optimize the resilience. To demonstrate our approach, we design and analyze an optimal resilient decentralized water supply system inspired by a real-life hotel building. KW - MINLP KW - Buffering Capacity KW - Uncertainty KW - Water Supply Networks KW - Booster Stations Y1 - 2018 U6 - http://dx.doi.org/10.4028/www.scientific.net/AMM.885.211 SN - 1662-7482 VL - 885 SP - 211 EP - 223 PB - Trans Tech Publications CY - Bäch ER - TY - BOOK A1 - Altherr, Lena T1 - Algorithmic System Design under Consideration of Dynamic Processes N2 - Nach Stand von Wissenschaft und Technik werden Komponenten hinsichtlich ihrer Eigenschaften, wie Lebensdauer oder Energieeffizienz, optimiert. Allerdings können selbst hervorragende Komponenten zu ineffizienten oder instabilen Systemen führen, wenn ihr Zusammenspiel nur unzureichend berücksichtigt wird. Eine Systembetrachtung schafft ein größeres Optimierungspotential - dem erhöhten Potential steht jedoch auch ein erhöhter Komplexitätsgrad gegenüber. Die vorliegende Arbeit ist im Rahmen des Sonderforschungsbereichs 805 entstanden, dessen Ziel die Beherrschung von Unsicherheit in Systemen des Maschinenbaus ist. Die Arbeit zeigt anhand eines realen Systems aus dem Bereich der Hydraulik, wie Unsicherheit in der Entwicklungsphase beherrscht werden kann. Hierbei ist neu, dass die durch den späteren Betrieb zu erwartende Systemdegradation eines jeden möglichen Systemvorschlags antizipiert werden kann. Dadurch können Betriebs- und Wartungskosten vorausgesagt und minimiert werden und durch eine optimale Betriebs- und Wartungsstrategie die Verfügbarkeit des Systems garantiert werden. Wesentliche Fragen bei der optimalen Auslegung des betrachteten hydrostatischen Getriebes sind dessen physikalische Modellierung, die Darstellung des Optimierungsproblems als gemischt-ganzzahliges lineares Programm, und dessen algorithmische Behandlung zur Lösungsfindung. Hierzu werden Heuristiken zum schnelleren Auffinden sinnvoller Systemtopologien vorgestellt und mittels mathematischer Dekomposition eine Bewertung des dynamischen Verschleiß- und Wartungsverlaufs möglicher Systemvorschläge vorgenommen. Die Arbeit stellt die Optimierung technischer Systeme an der Schnittstelle von Mathematik, Informatik und Ingenieurwesen sowohl gründlich als auch anschaulich und nachvollziehbar dar. KW - Mixed Integer Programming KW - Technical Operations Research KW - Optimization KW - System Design Y1 - 2016 SN - 978-3-8440-4848-3 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Altherr, Lena A1 - Ederer, Thorsten A1 - Schänzle, Christian A1 - Lorenz, Ulf A1 - Pelz, Peter F. T1 - Algorithmic system design using scaling and affinity laws T2 - Operations Research Proceedings 2015 N2 - Energy-efficient components do not automatically lead to energy-efficient systems. Technical Operations Research (TOR) shifts the focus from the single component to the system as a whole and finds its optimal topology and operating strategy simultaneously. In previous works, we provided a preselected construction kit of suitable components for the algorithm. This approach may give rise to a combinatorial explosion if the preselection cannot be cut down to a reasonable number by human intuition. To reduce the number of discrete decisions, we integrate laws derived from similarity theory into the optimization model. Since the physical characteristics of a production series are similar, it can be described by affinity and scaling laws. Making use of these laws, our construction kit can be modeled more efficiently: Instead of a preselection of components, it now encompasses whole model ranges. This allows us to significantly increase the number of possible set-ups in our model. In this paper, we present how to embed this new formulation into a mixed-integer program and assess the run time via benchmarks. We present our approach on the example of a ventilation system design problem. KW - Optimal Topology KW - Piecewise Linearization KW - Ventilation System KW - Similarity Theory Y1 - 2017 SN - 978-3-319-42901-4 SN - 978-3-319-42902-1 U6 - http://dx.doi.org/10.1007/978-3-319-42902-1 N1 - International Conference of the German, Austrian and Swiss Operations Research Societies (GOR, ÖGOR, SVOR/ASRO), University of Vienna, Austria, September 1-4, 2015 SP - 605 EP - 611 PB - Springer CY - Cham ER - TY - JOUR A1 - Grotendorst, Johannes T1 - Algorithms of mixed symbolic-numeric type for rational approximation JF - Artificial intelligence, expert systems and symbolic computing : selected and revised papers from the IMACS 13th World Congress [on Computation and Applied Mathematics], Dublin, Ireland, July 1991 / ed. by Elias N. Houstis ... Y1 - 1992 SN - 0-444-89703-8 N1 - zgl. Technical Report KFA-ZAM-IB-9205 ; World Congress on Computation and Applied Mathematics <13, 1991, Dublin> ; International Association for Mathematics and Computers in Simulation SP - 145 EP - 154 PB - North-Holland CY - Amsterdam ER - TY - JOUR A1 - Jeromin, Günter Erich A1 - Scheidt, Annette T1 - Aliphatic optically active alcohols by enzyme-aided synthesis JF - Tetrahedron Letters . 32 (1991), H. 48 Y1 - 1991 SN - 0040-4039 N1 - ISSN der E-Ausg.: 1359-8562 SP - 7021 EP - 7024 ER - TY - CHAP A1 - Dylla, Frank A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard T1 - AllemaniACs 2003 team description T2 - RoboCup 2003 : Robot Soccer World Cup VII Y1 - 2003 SP - 1 EP - 3 ER - TY - JOUR A1 - Vorst, Phillip A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard T1 - AllemaniACs3D team description Y1 - 2006 SP - 1 EP - 6 ER - TY - CHAP A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard A1 - Schiffer, Stefan T1 - AllemaniACs@ home 2006 team description Y1 - 2006 SP - 1 EP - 6 ER - TY - JOUR A1 - Gaigall, Daniel ED - AitSahlia, Farid T1 - Allocating and forecasting changes in risk JF - Journal of risk N2 - We consider time-dependent portfolios and discuss the allocation of changes in the risk of a portfolio to changes in the portfolio’s components. For this purpose we adopt established allocation principles. We also use our approach to obtain forecasts for changes in the risk of the portfolio’s components. To put the approach into practice we present an implementation based on the output of a simulation. Allocation is illustrated with an example portfolio in the context of Solvency II. The quality of the forecasts is investigated with an empirical study. KW - portfolio risk KW - allocation KW - forecast KW - covariance principle KW - conditional expectation principle Y1 - 2023 U6 - http://dx.doi.org/10.21314/JOR.2022.048 SN - 1755-2842 SN - 1465-1211 VL - 25 IS - 3 SP - 1 EP - 24 PB - Infopro Digital Risk CY - London ER - TY - JOUR A1 - Hoyler, Friedrich A1 - Mohr, P. A1 - Staudt, G. T1 - Alpha-cluster states of 212po in a realistic potential model JF - Physical review / C. 50 (1994), H. 5 Y1 - 1994 SN - 0556-2813 SP - 2631 EP - 2634 ER -