@article{Alt2007, author = {Alt, Helmut}, title = {Leser: Es wurde nichts verschenkt}, series = {Handelsblatt : Deutschlands Wirtschafts- und Finanzzeitung vom 5.1.2007}, journal = {Handelsblatt : Deutschlands Wirtschafts- und Finanzzeitung vom 5.1.2007}, pages = {18}, year = {2007}, language = {de} } @article{Alt2005, author = {Alt, Helmut}, title = {Wunschphantasie eines eingefleischten Kernenergiegegners : zur Rede von Bundesumweltminister J{\"u}rgen Trittin auf dem VDEW-Kongress 2005 "Die Energieversorgung der Zukunft"}, series = {EW : das Magazin f{\"u}r die Energie-Wirtschaft}, volume = {Bd. 104}, journal = {EW : das Magazin f{\"u}r die Energie-Wirtschaft}, number = {H. 17/18}, issn = {0013-5496}, pages = {7}, year = {2005}, language = {de} } @article{Alt2005, author = {Alt, Helmut}, title = {Versorgungssicherheit und Windenergie : Tatsachen und Fakten statt Mythen und Mysterien}, series = {EW : das Magazin f{\"u}r die Energie-Wirtschaft}, volume = {Bd. 104}, journal = {EW : das Magazin f{\"u}r die Energie-Wirtschaft}, number = {H. 25}, issn = {0013-5496}, pages = {42 -- 45}, year = {2005}, language = {de} } @article{Alt2011, author = {Alt, Helmut}, title = {Die Sonne bestimmt zunehmend die Spannung in der Steckdose : Lastflussberechnung einer Photovoltaikeinspeisung}, series = {EW : das Magazin f{\"u}r die Energie-Wirtschaft}, volume = {Bd. 110}, journal = {EW : das Magazin f{\"u}r die Energie-Wirtschaft}, number = {H. 17/18}, publisher = {VWEW-Energieverlag}, address = {Frankfurt, M.}, issn = {0013-5496}, pages = {24 -- 29}, year = {2011}, language = {de} } @inproceedings{Alt2003, author = {Alt, Helmut}, title = {Energiewirtschaftliche Bedeutung der Windenergie}, series = {Fortschrittliche Energiewandlung und -anwendung 2003 : Tagung Stuttgart, 11. und 12. M{\"a}rz 2003. (VDI-Berichte ; 1746)}, booktitle = {Fortschrittliche Energiewandlung und -anwendung 2003 : Tagung Stuttgart, 11. und 12. M{\"a}rz 2003. (VDI-Berichte ; 1746)}, organization = {Gesellschaft Energietechnik}, isbn = {3-18-091746-6}, pages = {447 -- 459}, year = {2003}, language = {de} } @inproceedings{Alt2000, author = {Alt, Helmut}, title = {Stand der Durchleitungspraxis auf Basis des neuen Energiewirtschaftsgesetzes}, series = {Energie und Umwelt 2000 : Fachkongreß und Ausstellung mit DBU-Statuskolloquium der Deutschen Bundesstiftung Umwelt: In situ-Bodenreaktor-Technologie, 29. bis 30. M{\"a}rz 2000 in Freiberg, Clemens-Winkler-Bau ; Tagungsband}, booktitle = {Energie und Umwelt 2000 : Fachkongreß und Ausstellung mit DBU-Statuskolloquium der Deutschen Bundesstiftung Umwelt: In situ-Bodenreaktor-Technologie, 29. bis 30. M{\"a}rz 2000 in Freiberg, Clemens-Winkler-Bau ; Tagungsband}, organization = {Technische Universit{\"a}t }, pages = {86 -- 88}, year = {2000}, language = {de} } @phdthesis{Alt1975, author = {Alt, Helmut}, title = {Beitrag zur Spannungs-Blindleistungsregelung mit gesteuerten Netzkennlinien}, address = {Aachen}, pages = {163 S.}, year = {1975}, language = {de} } @article{Alt1976, author = {Alt, Helmut}, title = {Spannungs-Blindleistungs-Regelung mit gesteuerten Netzkennlinien}, series = {Elektrotechnische Zeitschrift : Ausgabe A, Zeitschrift f{\"u}r elektrische Energietechnik : ETZ}, volume = {97}, journal = {Elektrotechnische Zeitschrift : Ausgabe A, Zeitschrift f{\"u}r elektrische Energietechnik : ETZ}, number = {7}, publisher = {VDE-Verlag}, address = {Wuppertal}, issn = {0302-265x}, pages = {441 -- 446}, year = {1976}, language = {de} } @article{Alt1985, author = {Alt, Helmut}, title = {Multiplikativ oder additiv? Diskussionsbeitrag zu Preisanpassungsklauseln in der Gaswirtschaft}, series = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, volume = {Jg. 35}, journal = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, issn = {0013-743X}, pages = {609 -- 611}, year = {1985}, language = {de} } @article{Alt1986, author = {Alt, Helmut}, title = {Steuersenkungsgesetz-Auswirkungen und Berechnung}, series = {Elektrizit{\"a}tswirtschaft}, volume = {Jg. 85}, journal = {Elektrizit{\"a}tswirtschaft}, issn = {0013-5496}, pages = {238 -- 242}, year = {1986}, language = {de} } @article{Alt1986, author = {Alt, Helmut}, title = {Dialoggesteuerte harmonische Analyse mit dem HP 41}, series = {Elektrizit{\"a}tswirtschaft}, volume = {Bd. 85}, journal = {Elektrizit{\"a}tswirtschaft}, number = {H. 4}, issn = {0013-5496}, pages = {139 -- 142}, year = {1986}, language = {de} } @article{Alt1986, author = {Alt, Helmut}, title = {Dialoggesteuerte harmonische Analyse mit dem HP 41}, series = {Elektrow{\"a}rme international Edition B : Industrielle Elektrow{\"a}rme : IEW = Industrial applications of electro-heat : EWI ; Zeitschr. f{\"u}r das gesamte Gebiet der Elektrow{\"a}rme in Industrie, Gewerbe und Haushalt}, volume = {Jg. 44}, journal = {Elektrow{\"a}rme international Edition B : Industrielle Elektrow{\"a}rme : IEW = Industrial applications of electro-heat : EWI ; Zeitschr. f{\"u}r das gesamte Gebiet der Elektrow{\"a}rme in Industrie, Gewerbe und Haushalt}, number = {H. 6}, issn = {0340-3521}, pages = {283 -- 287}, year = {1986}, language = {de} } @article{Alt1986, author = {Alt, Helmut}, title = {Dialoggesteuerte Spannungs- und Belastungsberechnung im Netz eines Elektrizit{\"a}tsversorgungsunternehmens}, series = {Elektrizit{\"a}tswirtschaft}, volume = {Bd. 85}, journal = {Elektrizit{\"a}tswirtschaft}, number = {H. 23}, issn = {0013-5496}, pages = {906 -- 910}, year = {1986}, language = {de} } @article{Alt1987, author = {Alt, Helmut}, title = {Effektivzinsberechnung bei industriellen oder gewerblichen Tilgungsdarlehen}, series = {Elektrizit{\"a}tswirtschaft}, volume = {Bd. 86}, journal = {Elektrizit{\"a}tswirtschaft}, issn = {0013-5496}, pages = {592 -- 595}, year = {1987}, language = {de} } @article{Alt1988, author = {Alt, Helmut}, title = {Die wichtigsten Kontof{\"u}hrungsmodelle}, series = {Frankfurter Zeitung : Blick durch die Wirtschaft : Zeitung f{\"u}r Finanzen, Steuern, Recht und Management}, journal = {Frankfurter Zeitung : Blick durch die Wirtschaft : Zeitung f{\"u}r Finanzen, Steuern, Recht und Management}, number = {Nr. 240 vom 13.12.1988}, pages = {3}, year = {1988}, language = {de} } @article{Alt1989, author = {Alt, Helmut}, title = {Steuerreformgesetz 1990}, series = {Elektrizit{\"a}tswirtschaft}, volume = {Bd. 88}, journal = {Elektrizit{\"a}tswirtschaft}, number = {H. 1/2}, issn = {0013-5496}, pages = {78 -- 83}, year = {1989}, language = {de} } @article{Alt1987, author = {Alt, Helmut}, title = {Steuersenkungs-Erweiterungsgesetz 1988 zur Gesamtentlastung der Einkommensteuer}, series = {Betriebs-Berater : BB ; Zeitschrift f{\"u}r Recht und Wirtschaft}, volume = {Vol. 42}, journal = {Betriebs-Berater : BB ; Zeitschrift f{\"u}r Recht und Wirtschaft}, number = {H. 32}, issn = {0340-7918}, pages = {2207 -- 2208}, year = {1987}, language = {de} } @article{Alt1989, author = {Alt, Helmut}, title = {Steuerreformgesetz 1990}, series = {Elektrizit{\"a}tswirtschaft}, volume = {Jg. 88}, journal = {Elektrizit{\"a}tswirtschaft}, number = {H. 2}, issn = {0947-0581 (E-Journal); 0340-7918 (Print)}, pages = {120 -- 121}, year = {1989}, language = {de} } @article{Alt1990, author = {Alt, Helmut}, title = {Energietarifstruktur in Ostdeutschland}, series = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, volume = {Bd. 40}, journal = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, number = {H. 11}, issn = {0013-743X}, pages = {782 -- 788}, year = {1990}, language = {de} } @article{Alt1991, author = {Alt, Helmut}, title = {Effektivzins und APR}, series = {Die Bank : Zeitschrift f{\"u}r Bankpolitik und Bankpraxis}, volume = {Jg. 31}, journal = {Die Bank : Zeitschrift f{\"u}r Bankpolitik und Bankpraxis}, number = {H. 4}, issn = {0342-3182}, pages = {230 -- 231}, year = {1991}, language = {de} } @article{Alt1992, author = {Alt, Helmut}, title = {M{\"o}glichkeiten der CO2-Minderung "alternativ" betrachtet}, series = {Etz : Elektrotechnik \& Automation}, volume = {Bd. 113}, journal = {Etz : Elektrotechnik \& Automation}, number = {H. 6-7}, issn = {0170-1711}, pages = {400}, year = {1992}, language = {de} } @article{Alt1995, author = {Alt, Helmut}, title = {Netzimpedanz- und Oberschwingungsberechnung in Netzen der {\"o}ffentlichen Stromversorgung}, series = {Elektrizit{\"a}tswirtschaft}, volume = {Bd. 94}, journal = {Elektrizit{\"a}tswirtschaft}, number = {H. 4}, issn = {0013-5496}, pages = {166 -- 174}, year = {1995}, language = {de} } @article{Alt1995, author = {Alt, Helmut}, title = {Netzanschlußm{\"o}glichkeiten und energiewirtschaftliche Bewertung von Windkraftanlagen}, series = {Elektrizit{\"a}tswirtschaft}, volume = {Jg. 94}, journal = {Elektrizit{\"a}tswirtschaft}, number = {H. 19}, issn = {0013-5496}, pages = {1224 -- 1234}, year = {1995}, language = {de} } @article{Alt2000, author = {Alt, Helmut}, title = {Benchmark der Netznutzungspreise}, series = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, volume = {Bd. 50}, journal = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, number = {H. 11}, issn = {0013-743X}, pages = {846 -- 850}, year = {2000}, language = {de} } @article{Alt1989, author = {Alt, Helmut}, title = {Zinsberechnung nach dem Sparbuch-Modell}, series = {Frankfurter Zeitung : Blick durch die Wirtschaft : Zeitung f{\"u}r Finanzen, Steuern, Recht und Management}, journal = {Frankfurter Zeitung : Blick durch die Wirtschaft : Zeitung f{\"u}r Finanzen, Steuern, Recht und Management}, pages = {vom 22.3.1989}, year = {1989}, language = {de} } @article{Alt1989, author = {Alt, Helmut}, title = {Die Bedeutung des Effektivzinses in der Finanzwirtschaft}, series = {Betriebs-Berater : BB : Beil. 14 Finanz-Berater}, journal = {Betriebs-Berater : BB : Beil. 14 Finanz-Berater}, issn = {0340-7926}, pages = {31 -- 32}, year = {1989}, language = {de} } @article{Alt1989, author = {Alt, Helmut}, title = {Einfluß der Kontof{\"u}hrungsmodelle auf den Effektivzins und die Restschuld bei Annuit{\"a}tendarlehen}, series = {Betriebs-Berater : BB : Beil. 14 Finanz-Berater}, journal = {Betriebs-Berater : BB : Beil. 14 Finanz-Berater}, issn = {0340-7926}, pages = {32 -- 37}, year = {1989}, language = {de} } @article{Alt2002, author = {Alt, Helmut}, title = {Belieferung von Kunden in fremden Netzgebieten}, series = {EW : das Magazin f{\"u}r die Energie-Wirtschaft}, volume = {Bd. 101}, journal = {EW : das Magazin f{\"u}r die Energie-Wirtschaft}, number = {H. 1/2}, issn = {0013-5496}, pages = {26 -- 35}, year = {2002}, language = {de} } @article{Alt1975, author = {Alt, Helmut}, title = {Elektro-Brikett-Zentralspeicherheizung soll die Spitzenlast der EVU schonen}, series = {Energiewirtschaftliche Tagesfragen}, volume = {25}, journal = {Energiewirtschaftliche Tagesfragen}, number = {4}, publisher = {VDE-Verlag}, address = {Berlin}, issn = {0720-6240}, pages = {148 -- 149}, year = {1975}, language = {de} } @article{Alt1974, author = {Alt, Helmut}, title = {Ab 1975 Uranerz aus Rabbit-Lake}, series = {Energiewirtschaftliche Tagesfragen}, volume = {24}, journal = {Energiewirtschaftliche Tagesfragen}, number = {1/2}, publisher = {VDE-Verlag}, address = {Berlin}, issn = {0720-6240}, pages = {34}, year = {1974}, language = {de} } @article{Alt1974, author = {Alt, Helmut}, title = {1,45 Mrd. DM f{\"u}r die Kohlevergasung}, series = {Energiewirtschaftliche Tagesfragen}, volume = {24}, journal = {Energiewirtschaftliche Tagesfragen}, number = {5}, publisher = {VDE-Verlag}, address = {Berlin}, issn = {0720-6240}, pages = {243 -- 244}, year = {1974}, language = {de} } @article{Alt1992, author = {Alt, Helmut}, title = {Renditevergleich zwischen Immobilien und Festverzinslichen}, series = {Die Bank}, journal = {Die Bank}, number = {H. 2}, issn = {0342-3182}, pages = {91 -- 92}, year = {1992}, language = {de} } @misc{Alt2016, author = {Alt, Helmut}, title = {Energiewende zwischen Wunsch und Wirklichkeit : Von der Grundlastdeckung zur L{\"u}ckenlastdeckung}, pages = {42 Folien}, year = {2016}, abstract = {Folien des Vortrags. VDI-Bezirksverband Dresden, Arbeitskreis Energietechnik, am Montag, 05.09.2016}, language = {de} } @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{AltPonten1993, author = {Alt, Helmut and Ponten, A.}, title = {Energiewirtschaftliche Bewertung der Einspeisung einer Windkraftanlage im Binnenland}, series = {ETG-Tage '93 am 20. und 21. Oktober 1993 in Mannheim : Ert{\"u}chtigung von Kraftwerken und Netzen, insbesondere in den neuen Bundesl{\"a}ndern : Plenarveranstaltung. (ETG-Fachbericht ; 47)}, booktitle = {ETG-Tage '93 am 20. und 21. Oktober 1993 in Mannheim : Ert{\"u}chtigung von Kraftwerken und Netzen, insbesondere in den neuen Bundesl{\"a}ndern : Plenarveranstaltung. (ETG-Fachbericht ; 47)}, organization = {Energietechnische Gesellschaft im VDE}, isbn = {3-8007-1967-3}, pages = {109 -- 118}, year = {1993}, language = {de} } @book{AltSchumny1983, author = {Alt, Helmut and Schumny, Harald}, title = {Schreiben, Zeichnen, Tabellieren : (TI-59, HP-41 C) (Vieweg-Programmbibliothek Taschenrechner ; 4) / Helmut Alt ; Harald Schumny [Hrsg.]}, publisher = {Vieweg + Teubner}, address = {Wiesbaden}, isbn = {3-528-04233-8}, pages = {77 S.}, year = {1983}, language = {de} } @book{AltSchumny1983, author = {Alt, Helmut and Schumny, Harald}, title = {Taschenrechnerarithmetik mit erh{\"o}hter Genauigkeit (TI-59/HP-41C) (Vieweg-Programmbibliothek Taschenrechner ; 2) / Helmut Alt ; Harald Schumny [Hrsg.]}, publisher = {Vieweg + Teubner}, address = {Wiesbaden}, isbn = {3-528-04229-X ; 978-3-322-91099-8 ; 978-3-528-04229-5}, pages = {III, 58 S.}, year = {1983}, language = {de} } @book{AltSchumny1982, author = {Alt, Helmut and Schumny, Harald}, title = {Programmierung mathematischer Algorithmen (Vieweg-Programmbibliothek Taschenrechner ; 1) / Helmut Alt ; Harald Schumny [Hrsg.]}, publisher = {Vieweg + Teubner}, address = {Wiesbaden}, isbn = {3-528-04211-7}, pages = {92 S.}, year = {1982}, language = {de} } @book{AltensenAltSchumny1983, author = {Altensen, Frank and Alt, Helmut and Schumny, Harald}, title = {Kryptologie (HP-41 C/CV) : Chiffrierung, Textverschl{\"u}sselung, Datenschutz, Morsealphabet (Vieweg-Programmbibliothek Taschenrechner ; 7) / Helmut Alt ; Harald Schumny [Hrsg.]}, publisher = {Vieweg + Teubner}, address = {Wiesbaden}, isbn = {3-528-04256-7}, pages = {V, 92 S.}, year = {1983}, language = {de} } @book{Altherr2016, author = {Altherr, Lena}, title = {Algorithmic System Design under Consideration of Dynamic Processes}, publisher = {Shaker}, address = {Aachen}, isbn = {978-3-8440-4848-3}, pages = {94}, year = {2016}, abstract = {Nach Stand von Wissenschaft und Technik werden Komponenten hinsichtlich ihrer Eigenschaften, wie Lebensdauer oder Energieeffizienz, optimiert. Allerdings k{\"o}nnen selbst hervorragende Komponenten zu ineffizienten oder instabilen Systemen f{\"u}hren, wenn ihr Zusammenspiel nur unzureichend ber{\"u}cksichtigt wird. Eine Systembetrachtung schafft ein gr{\"o}ßeres Optimierungspotential - dem erh{\"o}hten Potential steht jedoch auch ein erh{\"o}hter Komplexit{\"a}tsgrad gegen{\"u}ber. 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 sp{\"a}teren Betrieb zu erwartende Systemdegradation eines jeden m{\"o}glichen Systemvorschlags antizipiert werden kann. Dadurch k{\"o}nnen Betriebs- und Wartungskosten vorausgesagt und minimiert werden und durch eine optimale Betriebs- und Wartungsstrategie die Verf{\"u}gbarkeit 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 L{\"o}sungsfindung. Hierzu werden Heuristiken zum schnelleren Auffinden sinnvoller Systemtopologien vorgestellt und mittels mathematischer Dekomposition eine Bewertung des dynamischen Verschleiß- und Wartungsverlaufs m{\"o}glicher Systemvorschl{\"a}ge vorgenommen. Die Arbeit stellt die Optimierung technischer Systeme an der Schnittstelle von Mathematik, Informatik und Ingenieurwesen sowohl gr{\"u}ndlich als auch anschaulich und nachvollziehbar dar.}, language = {en} } @article{AltherrBroetzDietrichetal.2018, author = {Altherr, Lena and Br{\"o}tz, Nicolas and Dietrich, Ingo and Gally, Tristan and Geßner, Felix and Kloberdanz, Hermann and Leise, Philipp and Pelz, Peter Franz and Schlemmer, Pia and Schmitt, Andreas}, title = {Resilience in mechanical engineering - a concept for controlling uncertainty during design, production and usage phase of load-carrying structures}, series = {Applied Mechanics and Materials}, volume = {885}, journal = {Applied Mechanics and Materials}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, isbn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.885.187}, pages = {187 -- 198}, year = {2018}, abstract = {Resilience as a concept has found its way into different disciplines to describe the ability of an individual or system to withstand and adapt to changes in its environment. In this paper, we provide an overview of the concept in different communities and extend it to the area of mechanical engineering. Furthermore, we present metrics to measure resilience in technical systems and illustrate them by applying them to load-carrying structures. By giving application examples from the Collaborative Research Centre (CRC) 805, we show how the concept of resilience can be used to control uncertainty during different stages of product life.}, language = {en} } @inproceedings{AltherrConzenElsenetal.2023, author = {Altherr, Lena and Conzen, Max and Elsen, Ingo and Frauenrath, Tobias and Lyrmann, Andreas}, title = {Sensor retrofitting of existing buildings in an interdisciplinary teaching project at university level}, series = {Tagungsband AALE 2023 : mit Automatisierung gegen den Klimawandel}, booktitle = {Tagungsband AALE 2023 : mit Automatisierung gegen den Klimawandel}, editor = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and Schwarz, Andr{\´e}}, publisher = {le-tex publishing services GmbH}, address = {Leipzig}, isbn = {978-3-910103-01-6}, doi = {10.33968/2023.04}, pages = {31 -- 40}, year = {2023}, abstract = {Existing residential buildings have an average lifetime of 100 years. Many of these buildings will exist for at least another 50 years. To increase the efficiency of these buildings while keeping costs at reasonable rates, they can be retrofitted with sensors that deliver information to central control units for heating, ventilation and electricity. This retrofitting process should happen with minimal intervention into existing infrastructure and requires new approaches for sensor design and data transmission. At FH Aachen University of Applied Sciences, students of different disciplines work together to learn how to design, build, deploy and operate such sensors. The presented teaching project already created a low power design for a combined CO2, temperature and humidity measurement device that can be easily integrated into most home automation systems}, language = {en} } @incollection{AltherrDoerigEdereretal.2017, author = {Altherr, Lena and D{\"o}rig, Bastian and Ederer, Thorsten and Pelz, Peter Franz and Pfetsch, Marc and Wolf, Jan}, title = {A mixed-integer nonlinear program for the design of gearboxes}, series = {Operations Research Proceedings 2016}, booktitle = {Operations Research Proceedings 2016}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-55701-4}, doi = {10.1007/978-3-319-55702-1_31}, pages = {227 -- 233}, year = {2017}, abstract = {Gearboxes are mechanical transmission systems that provide speed and torque conversions from a rotating power source. Being a central element of the drive train, they are relevant for the efficiency and durability of motor vehicles. In this work, we present a new approach for gearbox design: Modeling the design problem as a mixed-integer nonlinear program (MINLP) allows us to create gearbox designs from scratch for arbitrary requirements and—given enough time—to compute provably globally optimal designs for a given objective. We show how different degrees of freedom influence the runtime and present an exemplary solution.}, language = {en} } @inproceedings{AltherrDoeringFrauenrathetal.2024, author = {Altherr, Lena and D{\"o}ring, Bernd and Frauenrath, Tobias and Groß, Rolf and Mohan, Nijanthan and Oyen, Marc and Schnittcher, Lukas and Voß, Norbert}, title = {DiggiTwin: ein interdisziplin{\"a}res Projekt zur Nutzung digitaler Zwillinge auf dem Weg zu einem klimaneutralen Geb{\"a}udebestand}, series = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation}, booktitle = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation}, editor = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and Schwarz, Andr{\´e}}, publisher = {le-tex publishing services GmbH}, address = {Leipzig}, isbn = {978-3-910103-02-3}, doi = {10.33968/2024.67}, pages = {341 -- 346}, year = {2024}, abstract = {Im Hinblick auf die Klimaziele der Bundesrepublik Deutschland konzentriert sich das Projekt Diggi Twin auf die nachhaltige Geb{\"a}udeoptimierung. Grundlage f{\"u}r eine ganzheitliche Geb{\"a}ude{\"u}berwachung und -optimierung bildet dabei die Digitalisierung und Automation im Sinne eines Smart Buildings. Das interdisziplin{\"a}re Projekt der FH Aachen hat das Ziel, ein bestehendes Hochschulgeb{\"a}ude und einen Neubau an klimaneutrale Standards anzupassen. Im Rahmen des Projekts werden bekannte Verfahren, wie das Building Information Modeling (BIM), so erweitert, dass ein digitaler Geb{\"a}udezwilling entsteht. Dieser kann zur Optimierung des Geb{\"a}udebetriebs herangezogen werden, sowie als Basis f{\"u}r eine Erweiterung des Bewertungssystems Nachhaltiges Bauen (BNB) dienen. Mithilfe von Sensortechnologie und k{\"u}nstlicher Intelligenz kann so ein pr{\"a}zises Monitoring wichtiger Geb{\"a}udedaten erfolgen, um ungenutzte Energieeinsparpotenziale zu erkennen und zu nutzen. Das Projekt erforscht und setzt methodische Erkenntnisse zu BIM und digitalen Geb{\"a}udezwillingen praxisnah um, indem es spezifische Fragen zur Energie- und Ressourceneffizienz von Geb{\"a}uden untersucht und konkrete L{\"o}sungen f{\"u}r die Geb{\"a}udeoptimierung entwickelt.}, language = {de} } @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} } @incollection{AltherrEdererLorenzetal.2016, author = {Altherr, Lena and Ederer, Thorsten and Lorenz, Ulf and Pelz, Peter F. and P{\"o}ttgen, Philipp}, title = {Designing a feedback control system via mixed-integer programming}, series = {Operations Research Proceedings 2014: Selected Papers of the Annual International Conference of the German Operations Research}, booktitle = {Operations Research Proceedings 2014: Selected Papers of the Annual International Conference of the German Operations Research}, editor = {L{\"u}bbecke, Marco E. and Koster, Arie and Letmathe, Peter and Madlener, Reihard and Preis, Britta and Walther, Grit}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-28695-2}, doi = {10.1007/978-3-319-28697-6_18}, pages = {121 -- 127}, year = {2016}, abstract = {Pure analytical or experimental methods can only find a control strategy for technical systems with a fixed setup. In former contributions we presented an approach that simultaneously finds the optimal topology and the optimal open-loop control of a system via Mixed Integer Linear Programming (MILP). In order to extend this approach by a closed-loop control we present a Mixed Integer Program for a time discretized tank level control. This model is the basis for an extension by combinatorial decisions and thus for the variation of the network topology. Furthermore, one is able to appraise feasible solutions using the global optimality gap.}, language = {en} } @article{AltherrEdererLorenzetal.2014, author = {Altherr, Lena and Ederer, Thorsten and Lorenz, Ulf and Pelz, Peter F. and P{\"o}ttgen, Philipp}, title = {Experimental validation of an enhanced system synthesis approach}, series = {Operations Research Proceedings 2014}, journal = {Operations Research Proceedings 2014}, editor = {L{\"u}bbecke, Marco and Koster, Arie and Letmathe, Peter and Madlener, Reihard and Peis, Britta and Walther, Grit}, publisher = {Springer}, address = {Basel}, isbn = {978-3-319-28695-2}, doi = {10.1007/978-3-319-28697-6_1}, pages = {6}, year = {2014}, abstract = {Planning the layout and operation of a technical system is a common task for an engineer. Typically, the workflow is divided into consecutive stages: First, the engineer designs the layout of the system, with the help of his experience or of heuristic methods. Secondly, he finds a control strategy which is often optimized by simulation. This usually results in a good operating of an unquestioned sys- tem topology. In contrast, we apply Operations Research (OR) methods to find a cost-optimal solution for both stages simultaneously via mixed integer program- ming (MILP). Technical Operations Research (TOR) allows one to find a provable global optimal solution within the model formulation. However, the modeling error due to the abstraction of physical reality remains unknown. We address this ubiq- uitous problem of OR methods by comparing our computational results with mea- surements in a test rig. For a practical test case we compute a topology and control strategy via MILP and verify that the objectives are met up to a deviation of 8.7\%.}, language = {en} } @article{AltherrEdererPfetschetal.2018, author = {Altherr, Lena and Ederer, Thorsten and Pfetsch, Marc E. and Pelz, Peter F.}, title = {Maschinelles Design eines optimalen Getriebes}, series = {ATZ - Automobiltechnische Zeitschrift}, volume = {120}, journal = {ATZ - Automobiltechnische Zeitschrift}, number = {10}, publisher = {Springer Nature}, address = {Cham}, isbn = {2192-8800}, doi = {10.1007/s35148-018-0131-3}, pages = {72 -- 77}, year = {2018}, abstract = {Nahezu 100.000 denkbare Strukturen kann ein Getriebe bei gleicher Funktion aufweisen - je nach Ganganzahl und gefordertem Freiheitsgrad. Mit dem traditionellen Ansatz bei der Entwicklung, einzelne vielversprechende Systemkonfigurationen manuell zu identifizieren und zu vergleichen, k{\"o}nnen leicht innovative und vor allem kostenminimale L{\"o}sungen {\"u}bersehen werden. Im Rahmen eines Forschungsprojekts hat die TU Darmstadt spezielle Optimierungsmethoden angewendet, um auch bei großen L{\"o}sungsr{\"a}umen zielsicher ein f{\"u}r die individuellen Zielstellungen optimales Layout zu finden.}, language = {de} } @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} } @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} }