@inproceedings{AltherrEdererSchaenzleetal.2017, author = {Altherr, Lena and Ederer, Thorsten and Sch{\"a}nzle, Christian and Lorenz, Ulf and Pelz, Peter F.}, title = {Algorithmic system design using scaling and affinity laws}, series = {Operations Research Proceedings 2015}, booktitle = {Operations Research Proceedings 2015}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-42901-4}, doi = {10.1007/978-3-319-42902-1}, pages = {605 -- 611}, year = {2017}, abstract = {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.}, language = {en} } @inproceedings{AltherrEdererVergeetal.2015, author = {Altherr, Lena and Ederer, Thorsten and Verg{\´e}, Angela and Pelz, Peter F.}, title = {Algorithmische Struktursynthese eines hydrostatischen Getriebes}, series = {Antriebssysteme 2015 : Elektrik, Mechanik, Fluidtechnik in der Anwendung}, booktitle = {Antriebssysteme 2015 : Elektrik, Mechanik, Fluidtechnik in der Anwendung}, publisher = {VDI-Verlag}, address = {D{\"u}sseldorf}, isbn = {978-3-18-092268-3}, pages = {145 -- 155}, year = {2015}, language = {de} } @inproceedings{SchaenzleAltherrEdereretal.2015, author = {Sch{\"a}nzle, Christian and Altherr, Lena and Ederer, Thorsten and Lorenz, Ulf and Pelz, Peter F.}, title = {As good as it can be: Ventilation system design by a combined scaling and discrete optimization method}, series = {Proceedings of FAN 2015}, booktitle = {Proceedings of FAN 2015}, pages = {1 -- 11}, year = {2015}, abstract = {The understanding that optimized components do not automatically lead to energy-efficient systems sets the attention from the single component on the entire technical system. At TU Darmstadt, a new field of research named Technical Operations Research (TOR) has its origin. It combines mathematical and technical know-how for the optimal design of technical systems. We illustrate our optimization approach in a case study for the design of a ventilation system with the ambition to minimize the energy consumption for a temporal distribution of diverse load demands. By combining scaling laws with our optimization methods we find the optimal combination of fans and show the advantage of the use of multiple fans.}, language = {en} } @article{PoettgenEdererAltherretal.2015, author = {P{\"o}ttgen, Philipp and Ederer, Thorsten and Altherr, Lena and Lorenz, Ulf and Pelz, Peter F.}, title = {Examination and optimization of a heating circuit for energy-efficient buildings}, series = {Energy Technology}, volume = {4}, journal = {Energy Technology}, number = {1}, publisher = {WILEY-VCH Verlag}, address = {Weinheim}, isbn = {2194-4296}, doi = {10.1002/ente.201500252}, pages = {136 -- 144}, year = {2015}, abstract = {The conference center darmstadtium in Darmstadt is a prominent example of energy efficient buildings. Its heating system consists of different source and consumer circuits connected by a Zortstr{\"o}m reservoir. Our goal was to reduce the energy costs of the system as much as possible. Therefore, we analyzed its supply circuits. The first step towards optimization is a complete examination of the system: 1) Compilation of an object list for the system, 2) collection of the characteristic curves of the components, and 3) measurement of the load profiles of the heat and volume-flow demand. Instead of modifying the system manually and testing the solution by simulation, the second step was the creation of a global optimization program. The objective was to minimize the total energy costs for one year. We compare two different topologies and show opportunities for significant savings.}, language = {en} } @inproceedings{AltherrEdererFarnetaneetal.2017, author = {Altherr, Lena and Ederer, Thorsten and Farnetane, Lucas S. and P{\"o}ttgen, Philipp and Verg{\´e}, Angela and Pelz, Peter F.}, title = {Multicriterial design of a hydrostatic transmission system via mixed-integer programming}, series = {Operations Research Proceedings 2015}, booktitle = {Operations Research Proceedings 2015}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-42901-4}, doi = {10.1007/978-3-319-42902-1_41}, pages = {301 -- 307}, year = {2017}, abstract = {In times of planned obsolescence the demand for sustainability keeps growing. Ideally, a technical system is highly reliable, without failures and down times due to fast wear of single components. At the same time, maintenance should preferably be limited to pre-defined time intervals. Dispersion of load between multiple components can increase a system's reliability and thus its availability inbetween maintenance points. However, this also results in higher investment costs and additional efforts due to higher complexity. Given a specific load profile and resulting wear of components, it is often unclear which system structure is the optimal one. Technical Operations Research (TOR) finds an optimal structure balancing availability and effort. We present our approach by designing a hydrostatic transmission system.}, language = {en} } @article{AltherrEdererPoettgenetal.2015, author = {Altherr, Lena and Ederer, Thorsten and P{\"o}ttgen, Philipp and Lorenz, Ulf and Pelz, Peter F.}, title = {Multicriterial optimization of technical systems considering multiple load and availability scenarios}, series = {Applied Mechanics and Materials}, volume = {807}, journal = {Applied Mechanics and Materials}, editor = {Pelz, Peter F. and Groche, Peter}, isbn = {1660-9336}, doi = {10.4028/www.scientific.net/AMM.807.247}, pages = {247 -- 256}, year = {2015}, abstract = {Cheap does not imply cost-effective -- this is rule number one of zeitgeisty system design. The initial investment accounts only for a small portion of the lifecycle costs of a technical system. In fluid systems, about ninety percent of the total costs are caused by other factors like power consumption and maintenance. With modern optimization methods, it is already possible to plan an optimal technical system considering multiple objectives. In this paper, we focus on an often neglected contribution to the lifecycle costs: downtime costs due to spontaneous failures. Consequently, availability becomes an issue.}, language = {en} } @incollection{Alt2022, author = {Alt, Helmut}, title = {Speicher speichern, Leiter leiten}, series = {Generationenprojekt Energiewende : Elektroenergiepolitik im Spannungsfeld zwischen Vision und Mission / Herbert Niederhausen (Hrsg.)}, booktitle = {Generationenprojekt Energiewende : Elektroenergiepolitik im Spannungsfeld zwischen Vision und Mission / Herbert Niederhausen (Hrsg.)}, publisher = {Books on Demand}, address = {Norderstedt}, isbn = {9783755774389}, pages = {125 -- 136}, year = {2022}, language = {de} } @inproceedings{OstkottePetersHueningetal.2022, author = {Ostkotte, Sebastian and Peters, Constantin and H{\"u}ning, Felix and Bragard, Michael}, title = {Design, implementation and verification of an rotational incremental position encoder based on the magnetic Wiegand effect}, series = {2022 ELEKTRO (ELEKTRO)}, booktitle = {2022 ELEKTRO (ELEKTRO)}, publisher = {IEEE}, isbn = {978-1-6654-6726-1}, issn = {2691-0616}, doi = {10.1109/ELEKTRO53996.2022.9803477}, pages = {6 Seiten}, year = {2022}, abstract = {This paper covers the use of the magnetic Wiegand effect to design an innovative incremental encoder. First, a theoretical design is given, followed by an estimation of the achievable accuracy and an optimization in open-loop operation. Finally, a successful experimental verification is presented. For this purpose, a permanent magnet synchronous machine is controlled in a field-oriented manner, using the angle information of the prototype.}, language = {en} } @inproceedings{BeckerHoefkenSchuetzetal.2016, author = {Becker, Sebastian and H{\"o}fken, Hans-Wilhelm and Sch{\"u}tz, Philip and Schuba, Marko}, title = {IT-forensische Erkennung modifizierter Android-Apps}, series = {Proceedings of DACH Security 2016, Klagenfurt, Austria, September 2016}, booktitle = {Proceedings of DACH Security 2016, Klagenfurt, Austria, September 2016}, editor = {Schartner, P.}, pages = {120 -- 125}, year = {2016}, abstract = {Malware auf Smartphones ist ein Problem, dem auch Strafverfolgungsbeh{\"o}rden immer h{\"a}ufiger gegen{\"u}berstehen. Insbesondere Telefone, bei denen potentiell schadhafte Apps zu einem finanziellen Schaden gef{\"u}hrt haben, finden sich auf den Schreibtischen der Polizei wieder. Dabei m{\"u}ssen die Ermittler m{\"o}glichst schnell und gezielt erkennen k{\"o}nnen, ob eine App tats{\"a}chlich schadhaft manipuliert wurde, was manipuliert wurde und mit wem die App kommuniziert. Klassische Malware-Erkennungsverfahren helfen zwar bei der generellen Erkennung schadhafter Software, sind aber f{\"u}r die polizeiliche Praxis nicht geeignet. Dieses Paper stellt ein Programm vor, welches gerade die forensischen Fragestellungen ber{\"u}cksichtigt und so f{\"u}r den Einsatz in der Strafverfolgung in Frage kommt.}, language = {de} } @inproceedings{BonneyNagelSchuba2016, author = {Bonney, Gregor and Nagel, Stefan and Schuba, Marko}, title = {Risiko Smart Home - Angriff auf ein Babymonitorsystem}, series = {Proceedings of DACH Security 2016, Klagenfurt, Austria, September 2016}, booktitle = {Proceedings of DACH Security 2016, Klagenfurt, Austria, September 2016}, editor = {Schartner, P.}, pages = {371 -- 378}, year = {2016}, abstract = {Unser Zuhause wird zunehmend intelligenter. Smart Homes bieten uns die Steuerung von Haus- oder Unterhaltungstechnik bequem vom Smartphone aus. Junge Familien nutzen die Technologie, um mittels vernetzten Babymonitorsystemen ihren Nachwuchs von {\"u}berall aus im Blick zu haben. Davon auszugehen, dass solche Systeme mit einem Fokus auf Sicherheit entwickelt wurden, um die sehr pers{\"o}nlichen Daten zu sch{\"u}tzen, ist jedoch ein Trugschluss. Die Untersuchung eines handels{\"u}blichen und keineswegs billigen Systems zeigt, dass die Ger{\"a}te sehr einfach kompromittiert und missbraucht werden k{\"o}nnen.}, language = {de} }