@inproceedings{LeiseAltherrPelz2018, author = {Leise, Philipp and Altherr, Lena and Pelz, Peter F.}, title = {Technical Operations Research (TOR) - Algorithms, not Engineers, Design Optimal Energy Efficient and Resilient Cooling Systems}, series = {FAN2018 - Proceedings of the International Conference on Fan Noise, Aerodynamics, Applications and Systems}, booktitle = {FAN2018 - Proceedings of the International Conference on Fan Noise, Aerodynamics, Applications and Systems}, pages = {1 -- 12}, year = {2018}, abstract = {The overall energy efficiency of ventilation systems can be improved by considering not only single components, but by considering as well the interplay between every part of the system. With the help of the method "TOR" ("Technical Operations Research"), which was developed at the Chair of Fluid Systems at TU Darmstadt, it is possible to improve the energy efficiency of the whole system by considering all possible design choices programmatically. We show the ability of this systematic design approach with a ventilation system for buildings as a use case example. Based on a Mixed-Integer Nonlinear Program (MINLP) we model the ventilation system. We use binary variables to model the selection of different pipe diameters. Multiple fans are model with the help of scaling laws. The whole system is represented by a graph, where the edges represent the pipes and fans and the nodes represents the source of air for cooling and the sinks, that have to be cooled. At the beginning, the human designer chooses a construction kit of different suitable fans and pipes of different diameters and different load cases. These boundary conditions define a variety of different possible system topologies. It is not possible to consider all topologies by hand. With the help of state of the art solvers, on the other side, it is possible to solve this MINLP. Next to this, we also consider the effects of malfunctions in different components. Therefore, we show a first approach to measure the resilience of the shown example use case. Further, we compare the conventional approach with designs that are more resilient. These more resilient designs are derived by extending the before mentioned model with further constraints, that consider explicitly the resilience of the overall system. We show that it is possible to design resilient systems with this method already in the early design stage and compare the energy efficiency and resilience of these different system designs.}, 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} } @incollection{LeiseAltherrPelz2018, author = {Leise, Philipp and Altherr, Lena and Pelz, Peter F.}, title = {Energy-Efficient design of a water supply system for skyscrapers by mixed-integer nonlinear programming}, series = {Operations Research Proceedings 2017}, booktitle = {Operations Research Proceedings 2017}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-89919-0}, doi = {10.1007/978-3-319-89920-6_63}, year = {2018}, abstract = {The energy-efficiency of technical systems can be improved by a systematic design approach. Technical Operations Research (TOR) employs methods known from Operations Research to find a global optimal layout and operation strategy of technical systems. We show the practical usage of this approach by the systematic design of a decentralized water supply system for skyscrapers. All possible network options and operation strategies are modeled by a Mixed-Integer Nonlinear Program. We present the optimal system found by our approach and highlight the energy savings compared to a conventional system design.}, language = {en} } @inproceedings{AltherrPelzEdereretal.2017, author = {Altherr, Lena and Pelz, Peter F. and Ederer, Thorsten and Pfetsch, Marc E.}, title = {Optimale Getriebe auf Knopfdruck: Gemischt-ganzzahlige nichtlineare Optimierung zur Entscheidungsunterst{\"u}tzung bei der Auslegung von Getrieben f{\"u}r Kraftfahrzeuge}, series = {Antriebstechnisches Kolloquium ATK 2017}, booktitle = {Antriebstechnisches Kolloquium ATK 2017}, editor = {Jacobs, Georg}, isbn = {9783743148970}, pages = {313 -- 325}, year = {2017}, language = {de} } @book{Feuerriegel2021, author = {Feuerriegel, Uwe}, title = {W{\"a}rme{\"u}bertragung mit EXCEL und VBA: W{\"a}rmetechnische Berechnungen und Simulationen effektiv durchf{\"u}hren und professionell dokumentieren}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-35905-8}, doi = {10.1007/978-3-658-35906-5}, pages = {XX, 439 Seiten}, year = {2021}, abstract = {Dieses Lehrbuch vermittelt die Grundlagen der W{\"a}rme{\"u}bertragung sowie den Umgang mit EXCEL-VBA von der Erstellung von Makros bis zu benutzerdefinierten Funktionen. Es legt damit eine Basis f{\"u}r die schnelle und professionelle Durchf{\"u}hrung von Berechnungen und Simulationen. Die angeleitete Erstellung von Berechnungsmodulen mit EXCEL und VBA aus allen wichtigen Bereichen der W{\"a}rme{\"u}bertragung bildet den inhaltlichen Schwerpunkt. Dazu z{\"a}hlen die station{\"a}re W{\"a}rmeleitung und der station{\"a}re W{\"a}rmedurchgang, die instation{\"a}re W{\"a}rmeleitung, der W{\"a}rme{\"u}bergang bei freier und erzwungener Konvektion sowie die W{\"a}rmestrahlung und der W{\"a}rme{\"u}bergang beim Kondensieren und Sieden. Soweit sinnvoll und m{\"o}glich werden die Stoffwertekorrelationen und die Berechnungsvorschriften aus dem VDI-W{\"a}rmeatlas verwendet. F{\"u}r ausgew{\"a}hlte Anwendungen werden zudem komplexere Auslegungen und Simulationen von Prozessen der W{\"a}rme{\"u}bertragung sowie von W{\"a}rme{\"u}bertragern erstellt. Die Zielgruppen: Studierende in Bachelor- und Masterstudieng{\"a}ngen, Praktiker im Engineering}, language = {de} } @inproceedings{RauschFriesenAltherretal.2018, author = {Rausch, Lea and Friesen, John and Altherr, Lena and Pelz, Peter F.}, title = {Using mixed-integer programming for the optimal design of water supply networks for slums}, series = {Operations Research Proceedings 2017}, booktitle = {Operations Research Proceedings 2017}, editor = {Kliewer, Natalia and Ehmke, Jan Fabian and Bornd{\"o}rfer, Ralf}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-89919-0 (Print)}, doi = {10.1007/978-3-319-89920-6_68}, pages = {509 -- 516}, year = {2018}, abstract = {The UN sets the goal to ensure access to water and sanitation for all people by 2030. To address this goal, we present a multidisciplinary approach for designing water supply networks for slums in large cities by applying mathematical optimization. The problem is modeled as a mixed-integer linear problem (MILP) aiming to find a network describing the optimal supply infrastructure. To illustrate the approach, we apply it on a small slum cluster in Dhaka, Bangladesh.}, language = {en} } @inproceedings{RauschLeiseEdereretal.2016, author = {Rausch, Lea and Leise, Philipp and Ederer, Thorsten and Altherr, Lena and Pelz, Peter F.}, title = {A comparison of MILP and MINLP solver performance on the example of a drinking water supply system design problem}, series = {ECCOMAS Congress 2016 VII European Congress on Computational Methods in Applied Sciences and Engineering}, booktitle = {ECCOMAS Congress 2016 VII European Congress on Computational Methods in Applied Sciences and Engineering}, editor = {Papadrakakis, M. and Ppadopoulos, V. and Stefanou, G. and Plevris, V.}, isbn = {978-618-82844-0-1}, pages = {8509 -- 8527}, year = {2016}, abstract = {Finding a good system topology with more than a handful of components is a highly non-trivial task. The system needs to be able to fulfil all expected load cases, but at the same time the components should interact in an energy-efficient way. An example for a system design problem is the layout of the drinking water supply of a residential building. It may be reasonable to choose a design of spatially distributed pumps which are connected by pipes in at least two dimensions. This leads to a large variety of possible system topologies. To solve such problems in a reasonable time frame, the nonlinear technical characteristics must be modelled as simple as possible, while still achieving a sufficiently good representation of reality. The aim of this paper is to compare the speed and reliability of a selection of leading mathematical programming solvers on a set of varying model formulations. This gives us empirical evidence on what combinations of model formulations and solver packages are the means of choice with the current state of the art.}, language = {en} } @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} } @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{RauschFriesenAltherretal.2018, author = {Rausch, Lea and Friesen, John and Altherr, Lena and Meck, Marvin and Pelz, Peter F.}, title = {A holistic concept to design optimal water supply infrastructures for informal settlements using remote sensing data}, series = {Remote Sensing}, volume = {10}, journal = {Remote Sensing}, number = {2}, publisher = {MDPI}, address = {Basel}, isbn = {2072-4292}, doi = {10.3390/rs10020216}, pages = {1 -- 23}, year = {2018}, abstract = {Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data.}, 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} } @inproceedings{MuellerAltherrAholaetal.2019, author = {M{\"u}ller, Tim M. and Altherr, Lena and Ahola, Marja and Schabel, Samuel and Pelz, Peter F.}, title = {Multi-Criteria optimization of pressure screen systems in paper recycling - balancing quality, yield, energy consumption and system complexity}, series = {EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization}, booktitle = {EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization}, editor = {Rodrigues, H. C.}, publisher = {Springer International Publishing}, address = {Basel}, isbn = {978-3-319-97773-7}, doi = {10.1007/978-3-319-97773-7_105}, year = {2019}, abstract = {The paper industry is the industry with the third highest energy consumption in the European Union. Using recycled paper instead of fresh fibers for papermaking is less energy consuming and saves resources. However, adhesive contaminants in recycled paper are particularly problematic since they reduce the quality of the resulting paper-product. To remove as many contaminants and at the same time obtain as many valuable fibres as possible, fine screening systems, consisting of multiple interconnected pressure screens, are used. Choosing the best configuration is a non-trivial task: The screens can be interconnected in several ways, and suitable screen designs as well as operational parameters have to be selected. Additionally, one has to face conflicting objectives. In this paper, we present an approach for the multi-criteria optimization of pressure screen systems based on Mixed-Integer Nonlinear Programming. We specifically focus on a clear representation of the trade-off between different objectives.}, 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} } @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 Pelz, Peter F.}, title = {Developing a control strategy for booster stations under uncertain load}, series = {Applied Mechanics and Materials}, volume = {807}, journal = {Applied Mechanics and Materials}, number = {807}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, isbn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.807.241}, pages = {241 -- 246}, year = {2015}, abstract = {Booster stations can fulfill a varying pressure demand with high energy-efficiency, because individual pumps can be deactivated at smaller loads. Although this is a seemingly simple approach, it is not easy to decide precisely when to activate or deactivate pumps. Contemporary activation controls derive the switching points from the current volume flow through the system. However, it is not measured directly for various reasons. Instead, the controller estimates the flow based on other system properties. This causes further uncertainty for the switching decision. In this paper, we present a method to find a robust, yet energy-efficient activation strategy.}, 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} } @techreport{Buedenbender2009, type = {Working Paper}, author = {B{\"u}denbender, Martin}, title = {Atomausstieg in Deutschland - ein zukunftsf{\"a}higer Sonderweg im europ{\"a}ischen Kontext?}, series = {Arbeitspapiere des Instituts f{\"u}r Genossenschaftswesen der Westf{\"a}lischen Wilhelms-Universit{\"a}t M{\"u}nster, Nr. 90}, journal = {Arbeitspapiere des Instituts f{\"u}r Genossenschaftswesen der Westf{\"a}lischen Wilhelms-Universit{\"a}t M{\"u}nster, Nr. 90}, pages = {41}, year = {2009}, language = {de} } @phdthesis{Buedenbender2012, author = {B{\"u}denbender, Martin}, title = {Entflechtungskonzepte f{\"u}r Strom{\"u}bertragungsnetze : ein {\"o}konomischer Vergleich}, series = {M{\"u}nstersche Schriften zur Kooperation ; Bd. 101}, journal = {M{\"u}nstersche Schriften zur Kooperation ; Bd. 101}, publisher = {Shaker}, address = {D{\"u}ren}, isbn = {978-3-8440-1460-0}, pages = {XVII, 401 S. : Ill., graph. Darst.}, year = {2012}, abstract = {Netzsektoren und deren ad{\"a}quate Regulierung sind ein sehr relevantes und aktuelles Thema. Dies gilt sowohl f{\"u}r die {\"o}konomische Theorie, die sich sehr intensiv damit auseinandersetzt und in den letzten Jahrzehnten zahlreiche neue Erkenntnisse gewonnen hat. Es gilt ebenso f{\"u}r die Politik, in der Regulierungsfragen kontrovers diskutiert werden und dies nicht nur unter {\"o}konomischen Gesichtspunkten. Es gilt selbstverst{\"a}ndlich f{\"u}r die regulierten Unternehmen selbst, deren T{\"a}tigkeit durch die staatlichen Regulierungsvorgaben markant beeinflusst wird. Nicht nur die konkreten Inhalte der Regulierungsregime sowie die verbleibenden Freiheitsgrade in der Ausgestaltung sind von Bedeutung, sondern ebenso die Umsetzung durch die Regulierungsbeh{\"o}rden. All dies gilt f{\"u}r den Strommarkt und seinen regulatorischen Hintergrund in besonderer Weise. Die Entflechtung der Strom{\"u}bertragungsnetze von der Stromproduktion und damit die Vorgaben f{\"u}r die Organisation der Wertsch{\"o}pfungsketten in den Elektrizit{\"a}tsunternehmen sind seit dem Beginn des europ{\"a}ischen Liberalisierungsprozesses der Stromm{\"a}rkte ein wichtiges und kontrovers diskutiertes Regulierungselement. Den Fokus bildet das vertikale Unbundling, das letztlich die Diskriminierung von Wettbewerbern durch Anbieter mit aggregierten Wertsch{\"o}pfungsketten verhindern soll, indem diese gezwungen werden, ihren "Netzteil" anders zu organisieren oder zu verkaufen. Den Mitgliedsstaaten blieben Freir{\"a}ume in der Ausgestaltung, die in Deutschland erst vor kurzem konkretisiert wurden, und die f{\"u}r die regulierten Unternehmen die Nutzung eines Wahlrechts beinhalten. Der wirtschaftspolitischen folgt nun eine unternehmerische Abw{\"a}gungsentscheidung.}, language = {de} } @book{Buedenbender2009, author = {B{\"u}denbender, Martin}, title = {Auswirkungen des europ{\"a}ischen CO2-Handelssystems auf Stromerzeugungsinvestitionen - m{\"o}gliche Ausgestaltung des Systems ab 2013}, series = {D{\"u}sseldorfer Schriften zum Energie- und Kartellrecht ; Bd. 13}, journal = {D{\"u}sseldorfer Schriften zum Energie- und Kartellrecht ; Bd. 13}, publisher = {etv Energieverlag}, address = {Essen}, isbn = {9783942370318}, pages = {140 S. : graph. Darst.}, year = {2009}, abstract = {Zahlreiche Einflussfaktoren haben in den vergangenen Jahren das Gesicht der Elektrizit{\"a}tsm{\"a}rkte stark ver{\"a}ndert. Hierzu z{\"a}hlen vor allem die Einf{\"u}hrung der {\"o}konomischen Gesetze des Wettbewerbsmarktes durch die Liberalisierung sowie die nun kostenpflichtige Ber{\"u}cksichtigung des bei der Stromerzeugung hervorgerufenen CO2-Ausstoßes durch die Einf{\"u}hrung des europ{\"a}ischen Emissionshandelssystems (EUTS). Die Folgen dieses Ver{\"a}nderungsprozesses lassen sich auf Grund der langen Investitionszyklen im Kraftwerksbau bisher nur unvollst{\"a}ndig {\"u}berblicken. Dies ist insbesondere im Hinblick auf die Versorgungssicherheit als Teil des energiewirtschaftlichen Zieldreiecks des \S 1 EnWG von großer Bedeutung. Dazu z{\"a}hlt insbesondere, ob die Versorgungssicherheit in Deutschland bei gegenw{\"a}rtigem Marktdesign auch dauerhaft gew{\"a}hrleistet sein wird. Es stellt sich heraus, dass es im Bereich der Spitzenlastkraftwerke zu Investitionen in gesamtwirtschaftlich zu geringen Umfang kommen kann. Dieses Investitionsdilemma beruht auf einem externen Effekt, der durch die aktuelle Ausgestaltung des deutschen Schadenersatzrechtes entsteht. Hierdurch ist die sichere Stromversorgung in Zeiten hoher Last potenziell gef{\"a}hrdet. Um die Wirkungen des Investitionsdilemmas abzumildern oder ganz zu beseitigen sind verschiedene Investitionsanreize durch entsprechende Ausgestaltung des EUTS denkbar. Diese werden im Einzelnen analysiert.}, language = {de} } @article{Buedenbender2009, author = {B{\"u}denbender, Martin}, title = {Auswirkungen der europ{\"a}ischen Energiepolitik auf den deutschen Atomausstieg}, series = {Zeitschrift f{\"u}r Energiewirtschaft}, volume = {33}, journal = {Zeitschrift f{\"u}r Energiewirtschaft}, number = {4}, publisher = {Vieweg}, address = {Wiesbaden}, isbn = {1866-2765}, doi = {10.1007/s12398-009-0039-4}, pages = {341 -- 350}, year = {2009}, abstract = {Nach der Bundestagswahl am 27. September 2009 steht der Atomausstieg in Deutschland wieder ganz oben auf der politischen Agenda. Eine aktuelle Bestandsaufnahme aller ma\geblichen Argumente erscheint somit zwingend notwendig. Dabei sollte der Blickwinkel nicht national beschr{\"a}nkt bleiben, sondern vor allem der Einfluss der europ{\"a}ischen Dimension dieser Thematik miteinbezogen werden. Auf europ{\"a}ischer Ebene zeigt sich eine Position zu Gunsten der Kernenergie. Unter den 27 EU-Staaten findet gerade eine Renaissance der Atomkraft statt. Die drei europ{\"a}ischen Organe bef{\"u}rworten den umfangreichen Einsatz der Kernenergie als langfristigen Bestandteil des Energietr{\"a}germix. Deutschland geh{\"o}rt mit seinem Beschluss zum Atomausstieg einer Minderheit an. Als Teil eines immer st{\"a}rker zusammen wachsenden und letztendlich vollst{\"a}ndig integrierten europ{\"a}ischen Strommarktes wird Deutschland langfristig stets mit Atomstrom versorgt werden. Dies gilt losgel{\"o}st von dem Einsatz von Kernkraftwerken im Inland. Eine Abschaltung der Anlagen f{\"u}hrt damit nicht zur Zielerreichung der Atomkraftgegner, sondern lediglich zu zus{\"a}tzlichen energietechnischen Herausforderungen bei der Sicherstellung der deutschen Stromversorgung. Der deutsche Atomausstieg sollte aus diesem Grund von der neuen Bundesregierung zur{\"u}ck genommen werden.}, language = {de} } @article{Buedenbender2009, author = {B{\"u}denbender, Martin}, title = {Der Atomausstieg in Deutschland - ein zukunftsf{\"a}higer Sonderweg im europ{\"a}ischen Kontext?}, series = {atw International Journal for Nuclear Power}, volume = {54}, journal = {atw International Journal for Nuclear Power}, number = {10}, publisher = {Inforum}, address = {Berlin}, issn = {14315254}, pages = {616 -- 627}, year = {2009}, language = {de} } @article{BuedenbenderJanssenWobben2009, author = {B{\"u}denbender, Martin and Janssen, Matthias and Wobben, Magnus}, title = {Versorgungssicherheit auf Elektrizit{\"a}tsm{\"a}rkten — Investitionsdilemma durch ineffizientes Marktdesign?}, series = {Zeitschrift f{\"u}r Energiewirtschaft}, volume = {33}, journal = {Zeitschrift f{\"u}r Energiewirtschaft}, number = {1}, issn = {1866-2765}, pages = {49 -- 61}, year = {2009}, abstract = {Dieser Artikel befasst sich mit dem Investitionsdilemma in der Stromerzeugung, welches in unzureichend ausgestalteten liberalisierten Stromm{\"a}rkten zu einem gesamtwirtschaftlich unerw{\"u}nscht geringen Niveau an Versorgungssicherheit f{\"u}hrt. Die origin{\"a}ren Ursachen im deutschen Strommarkt liegen in einer eingeschr{\"a}nkten Schadenersatzpflicht der Lieferanten im Falle eines kapazit{\"a}tsbedingten Stromausfalls und in der zeitlichen Differenz zwischen letzter Handelsm{\"o}glichkeit und Lieferung. Letzteres verhindert ein jederzeitiges individuelles Glattstellen von unerwartet auftretenden Ein- bzw. Ausspeise{\"a}nderungen. Des Weiteren f{\"u}hren Faktoren wie die fehlende Partizipation der Endverbraucher am Großhandelsmarkt, die nur undifferenziert m{\"o}gliche Abschaltung von Endverbrauchern oder time lags durch lange Bau- und Genehmigungszeiten von Erzeugungskapazit{\"a}ten in Verbindung mit {\"u}ber lange Zeitr{\"a}ume nicht versicherbaren Risiken bez{\"u}glich Brennstoff-, CO2-Zertifikate- und Strompreisen zu einer Versch{\"a}rfung der Problematik. Sinnvolle L{\"o}sungsans{\"a}tze sind zum einen die Erh{\"o}hung der Intraday-Handelsliquidit{\"a}t zur Verbesserung der Marktr{\"a}umungsfunktion bis m{\"o}glichst kurz vor Stromlieferung, was z. B. durch eine F{\"o}rderung der Direktvermarktung Erneuerbarer Energien erreicht werden kann. Zum anderen tr{\"a}gt ein verst{\"a}rkter Ausbau von smart metern bei Endverbrauchern zu einer h{\"o}heren Versorgungssicherheit bei, da dies die Gl{\"a}ttung von Lastspitzen und die Artikulation der tats{\"a}chlichen Zahlungsbereitschaft von Endverbrauchern am Großhandelsmarkt erm{\"o}glicht.}, language = {de} } @techreport{Buedenbender2010, type = {Working Paper}, author = {B{\"u}denbender, Martin}, title = {Entflechtung von Stromnetzen in Deutschland und Europa im Rahmen des dritten EU-Legislativpakets - Eine Problemdarstellung}, series = {Arbeitspapiere des Instituts f{\"u}r Genossenschaftswesen der Westf{\"a}lischen Wilhelms-Universit{\"a}t M{\"u}nster, Nr. 91}, journal = {Arbeitspapiere des Instituts f{\"u}r Genossenschaftswesen der Westf{\"a}lischen Wilhelms-Universit{\"a}t M{\"u}nster, Nr. 91}, pages = {35}, year = {2010}, 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{BuesgenKloeserKohletal.2022, author = {B{\"u}sgen, Andr{\´e} and Kl{\"o}ser, Lars and Kohl, Philipp and Schmidts, Oliver and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {Exploratory analysis of chat-based black market profiles with natural language processing}, series = {Proceedings of the 11th International Conference on Data Science, Technology and Applications}, booktitle = {Proceedings of the 11th International Conference on Data Science, Technology and Applications}, isbn = {978-989-758-583-8}, issn = {2184-285X}, doi = {10.5220/0011271400003269}, pages = {83 -- 94}, year = {2022}, abstract = {Messenger apps like WhatsApp or Telegram are an integral part of daily communication. Besides the various positive effects, those services extend the operating range of criminals. Open trading groups with many thousand participants emerged on Telegram. Law enforcement agencies monitor suspicious users in such chat rooms. This research shows that text analysis, based on natural language processing, facilitates this through a meaningful domain overview and detailed investigations. We crawled a corpus from such self-proclaimed black markets and annotated five attribute types products, money, payment methods, user names, and locations. Based on each message a user sends, we extract and group these attributes to build profiles. Then, we build features to cluster the profiles. Pretrained word vectors yield better unsupervised clustering results than current state-of-the-art transformer models. The result is a semantically meaningful high-level overview of the user landscape of black market chatrooms. Additionally, the extracted structured information serves as a foundation for further data exploration, for example, the most active users or preferred payment methods.}, language = {en} } @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} } @book{Engelmann2022, author = {Engelmann, Ulrich M.}, title = {Zielf{\"u}hrend moderieren}, publisher = {UVK Verlag}, address = {Stuttgart}, isbn = {9783838556895}, doi = {10.36198/9783838556895}, pages = {438 S.}, year = {2022}, abstract = {In der Teamarbeit wird Moderation zum Erfolgsfaktor, der jedoch h{\"a}ufig untersch{\"a}tzt wird. Ausgehend vom pers{\"o}nlichen Kompetenzniveau verkn{\"u}pft dieses Buch Grundlagen und Methoden zu Wegen, um Ihre pers{\"o}nliche Entwicklung individuell zu begleiten: Neulinge finden hilfreiche Checklisten und Basistechniken f{\"u}r ihre ersten Moderationen, Fortgeschrittene wertvolle Praxistipps und Methoden f{\"u}r den Ausbau ihrer Moderationskompetenz. Profis schließlich genießen eine raffinierte Aussicht auf weniger bekannte Techniken und neue Anwendungen. Weiterf{\"u}hrende Exkurse zum Meeting-Management und zur Online-Moderation runden den Anwendungshorizont ab. Ob in Beruf, Studium oder Ehrenamt - derart ausgestattet gelingen Ihre eigene sowie die Entwicklung Ihres Teams durch zielf{\"u}hrende Moderationen.}, language = {de} } @article{MandekarHollandThielenetal.2022, author = {Mandekar, Swati and Holland, Abigail and Thielen, Moritz and Behbahani, Mehdi and Melnykowycz, Mark}, title = {Advancing towards Ubiquitous EEG, Correlation of In-Ear EEG with Forehead EEG}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s22041568}, pages = {1 -- 19}, year = {2022}, abstract = {Wearable EEG has gained popularity in recent years driven by promising uses outside of clinics and research. The ubiquitous application of continuous EEG requires unobtrusive form-factors that are easily acceptable by the end-users. In this progression, wearable EEG systems have been moving from full scalp to forehead and recently to the ear. The aim of this study is to demonstrate that emerging ear-EEG provides similar impedance and signal properties as established forehead EEG. EEG data using eyes-open and closed alpha paradigm were acquired from ten healthy subjects using generic earpieces fitted with three custom-made electrodes and a forehead electrode (at Fpx) after impedance analysis. Inter-subject variability in in-ear electrode impedance ranged from 20 kΩ to 25 kΩ at 10 Hz. Signal quality was comparable with an SNR of 6 for in-ear and 8 for forehead electrodes. Alpha attenuation was significant during the eyes-open condition in all in-ear electrodes, and it followed the structure of power spectral density plots of forehead electrodes, with the Pearson correlation coefficient of 0.92 between in-ear locations ELE (Left Ear Superior) and ERE (Right Ear Superior) and forehead locations, Fp1 and Fp2, respectively. The results indicate that in-ear EEG is an unobtrusive alternative in terms of impedance, signal properties and information content to established forehead EEG.}, language = {en} } @incollection{AltherrLeise2021, author = {Altherr, Lena and Leise, Philipp}, title = {Resilience as a concept for mastering uncertainty}, series = {Mastering Uncertainty in Mechanical Engineering}, booktitle = {Mastering Uncertainty in Mechanical Engineering}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-78353-2}, doi = {10.1007/978-3-030-78354-9}, pages = {412 -- 417}, year = {2021}, 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} } @incollection{LeiseAltherr2021, author = {Leise, Philipp and Altherr, Lena}, title = {Experimental evaluation of resilience metrics in a fluid system}, series = {Mastering Uncertainty in Mechanical Engineering}, booktitle = {Mastering Uncertainty in Mechanical Engineering}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-78356-3}, pages = {442 -- 447}, year = {2021}, language = {en} } @inproceedings{LorenzAltherrPelz2020, author = {Lorenz, Imke-Sophie and Altherr, Lena and Pelz, Peter F.}, title = {Resilience enhancement of critical infrastructure - graph-theoretical resilience analysis of the water distribution system in the German city of Darmstadt}, series = {14th WCEAM Proceedings}, booktitle = {14th WCEAM Proceedings}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-64228-0}, doi = {10.1007/978-3-030-64228-0_13}, pages = {137 -- 149}, year = {2020}, abstract = {Water suppliers are faced with the great challenge of achieving high-quality and, at the same time, low-cost water supply. Since climatic and demographic influences will pose further challenges in the future, the resilience enhancement of water distribution systems (WDS), i.e. the enhancement of their capability to withstand and recover from disturbances, has been in particular focus recently. To assess the resilience of WDS, graph-theoretical metrics have been proposed. In this study, a promising approach is first physically derived analytically and then applied to assess the resilience of the WDS for a district in a major German City. The topology based resilience index computed for every consumer node takes into consideration the resistance of the best supply path as well as alternative supply paths. This resistance of a supply path is derived to be the dimensionless pressure loss in the pipes making up the path. The conducted analysis of a present WDS provides insight into the process of actively influencing the resilience of WDS locally and globally by adding pipes. The study shows that especially pipes added close to the reservoirs and main branching points in the WDS result in a high resilience enhancement of the overall WDS.}, language = {en} } @inproceedings{SchaenzleAltherrEdereretal.2015, author = {Sch{\"a}nzle, Christian and Altherr, Lena and Ederer, Thorsten and Pelz, Peter}, title = {TOR - Towards the energetically optimal ventilation system}, pages = {1 Seite}, year = {2015}, language = {en} } @inproceedings{NikolovskiRekeElsenetal.2021, author = {Nikolovski, Gjorgji and Reke, Michael and Elsen, Ingo and Schiffer, Stefan}, title = {Machine learning based 3D object detection for navigation in unstructured environments}, series = {2021 IEEE Intelligent Vehicles Symposium Workshops (IV Workshops)}, booktitle = {2021 IEEE Intelligent Vehicles Symposium Workshops (IV Workshops)}, publisher = {IEEE}, isbn = {978-1-6654-7921-9}, doi = {10.1109/IVWorkshops54471.2021.9669218}, pages = {236 -- 242}, year = {2021}, abstract = {In this paper we investigate the use of deep neural networks for 3D object detection in uncommon, unstructured environments such as in an open-pit mine. While neural nets are frequently used for object detection in regular autonomous driving applications, more unusual driving scenarios aside street traffic pose additional challenges. For one, the collection of appropriate data sets to train the networks is an issue. For another, testing the performance of trained networks often requires tailored integration with the particular domain as well. While there exist different solutions for these problems in regular autonomous driving, there are only very few approaches that work for special domains just as well. We address both the challenges above in this work. First, we discuss two possible ways of acquiring data for training and evaluation. That is, we evaluate a semi-automated annotation of recorded LIDAR data and we examine synthetic data generation. Using these datasets we train and test different deep neural network for the task of object detection. Second, we propose a possible integration of a ROS2 detector module for an autonomous driving platform. Finally, we present the performance of three state-of-the-art deep neural networks in the domain of 3D object detection on a synthetic dataset and a smaller one containing a characteristic object from an open-pit mine.}, language = {en} } @article{Maurischat2022, author = {Maurischat, Andreas}, title = {Algebraic independence of the Carlitz period and its hyperderivatives}, series = {Journal of Number Theory}, volume = {240}, journal = {Journal of Number Theory}, publisher = {Elsevier}, address = {Orlando, Fla.}, issn = {0022-314X}, doi = {10.1016/j.jnt.2022.01.006}, pages = {145 -- 162}, year = {2022}, language = {en} } @inproceedings{AmirBauckhageChircuetal.2022, author = {Amir, Malik and Bauckhage, Christian and Chircu, Alina and Czarnecki, Christian and Knopf, Christian and Piatkowski, Nico and Sultanow, Eldar}, title = {What can we expect from quantum (digital) twins?}, series = {Wirtschaftsinformatik 2022 Proceedings}, booktitle = {Wirtschaftsinformatik 2022 Proceedings}, publisher = {AIS Electronic Library (AISeL)}, pages = {1 -- 14}, year = {2022}, abstract = {Digital twins enable the modeling and simulation of real-world entities (objects, processes or systems), resulting in improvements in the associated value chains. The emerging field of quantum computing holds tremendous promise forevolving this virtualization towards Quantum (Digital) Twins (QDT) and ultimately Quantum Twins (QT). The quantum (digital) twin concept is not a contradiction in terms - but instead describes a hybrid approach that can be implemented using the technologies available today by combining classicalcomputing and digital twin concepts with quantum processing. This paperpresents the status quo of research and practice on quantum (digital) twins. It alsodiscuses their potential to create competitive advantage through real-timesimulation of highly complex, interconnected entities that helps companies better address changes in their environment and differentiate their products andservices.}, language = {en} } @inproceedings{RitschelStenzelCzarneckietal.2021, author = {Ritschel, Konstantin and Stenzel, Adina and Czarnecki, Christian and Hong, Chin-Gi}, title = {Realizing robotic process automation potentials: an architectural perspective on a real-life implementation case}, series = {GI Edition Proceedings Band 314 "INFORMATIK 2021" Computer Science \& Sustainability}, booktitle = {GI Edition Proceedings Band 314 "INFORMATIK 2021" Computer Science \& Sustainability}, editor = {Gesellschaft f{\"u}r Informatik e.V. (GI),}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885797081}, issn = {1617-5468}, doi = {10.18420/informatik2021-108}, pages = {1303 -- 1311}, year = {2021}, abstract = {The initial idea of Robotic Process Automation (RPA) is the automation of business processes through a simple emulation of user input and output by software robots. Hence, it can be assumed that no changes of the used software systems and existing Enterprise Architecture (EA) is required. In this short, practical paper we discuss this assumption based on a real-life implementation project. We show that a successful RPA implementation might require architectural work during analysis, implementation, and migration. As practical paper we focus on exemplary lessons-learned and new questions related to RPA and EA.}, language = {en} } @inproceedings{AuthCzarneckiBensberg2019, author = {Auth, Gunnar and Czarnecki, Christian and Bensberg, Frank}, title = {Impact of robotic process automation on enterprise architectures}, series = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, booktitle = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, editor = {Draude, Claude and Lange, Martin and Sick, Bernhard and Gesellschaft f{\"u}r Informatik e.V. (GI),}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885796893}, issn = {1617-5468}, doi = {10.18420/inf2019_ws05}, pages = {59 -- 65}, year = {2019}, abstract = {The initial idea of Robotic Process Automation (RPA) is the automation of business processes through the presentation layer of existing application systems. For this simple emulation of user input and output by software robots, no changes of the systems and architecture is required. However, considering strategic aspects of aligning business and technology on an enterprise level as well as the growing capabilities of RPA driven by artificial intelligence, interrelations between RPA and Enterprise Architecture (EA) become visible and pose new questions. In this paper we discuss the relationship between RPA and EA in terms of perspectives and implications. As workin- progress we focus on identifying new questions and research opportunities related to RPA and EA.}, language = {en} } @inproceedings{BrockmannSultanowCzarnecki2019, author = {Brockmann, Carsten and Sultanow, Eldar and Czarnecki, Christian}, title = {Is enterprise architecture still relevant in the digital age?}, series = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, booktitle = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, editor = {Draude, Claude and Lange, Martin and Sick, Bernhard}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885796893}, issn = {1617-5468}, doi = {10.18420/inf2019_ws01}, pages = {21 -- 21}, year = {2019}, language = {en} } @inproceedings{BensbergAuthCzarneckietal.2018, author = {Bensberg, Frank and Auth, Gunnar and Czarnecki, Christian and W{\"o}rndle, Christopher}, title = {Transforming literature-intensive research processes through text analytics - design, implementation and lessons learned}, editor = {Kemal İlter, H.}, doi = {10.6084/m9.figshare.7582073.v1}, pages = {9 Seiten}, year = {2018}, abstract = {The continuing growth of scientific publications raises the question how research processes can be digitalized and thus realized more productively. Especially in information technology fields, research practice is characterized by a rapidly growing volume of publications. For the search process various information systems exist. However, the analysis of the published content is still a highly manual task. Therefore, we propose a text analytics system that allows a fully digitalized analysis of literature sources. We have realized a prototype by using EBSCO Discovery Service in combination with IBM Watson Explorer and demonstrated the results in real-life research projects. Potential addressees are research institutions, consulting firms, and decision-makers in politics and business practice.}, language = {en} } @inproceedings{BrockmannSultanowCzarnecki2018, author = {Brockmann, Carsten and Sultanow, Eldar and Czarnecki, Christian}, title = {Enterprise architectures between agility and traditional methodologies}, series = {GI Edition Proceedings Band 285 Workshops der INFORMATIK 2018}, booktitle = {GI Edition Proceedings Band 285 Workshops der INFORMATIK 2018}, editor = {Czarnecki, Christian and Brockmann, Carsten and Sultanow, Eldar and Koschmider, Agnes and Selzer, Annika and Gesellschaft f{\"u}r Informatik e. V.,}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885796794}, issn = {1617-5468}, pages = {1 Seite}, year = {2018}, abstract = {For this year's workshop on Enterpirse Architecture in Research and Practice we have received eight submissions from which four have passed the rigorous peer-review. The acceptance quote of 50\% assures that only advancements in the field are included in our workshop.}, language = {en} } @article{PhilippEfthimiouPaganoetal.2022, author = {Philipp, Mohr and Efthimiou, Nikos and Pagano, Fiammetta and Kratochwil, Nicolaus and Pizzichemi, Marco and Tsoumpas, Charalampos and Auffray, Etiennette and Ziemons, Karl}, title = {Image reconstruction analysis for positron emission tomography with heterostructured scintillators}, series = {IEEE Transactions on Radiation and Plasma Medical Sciences}, volume = {7}, journal = {IEEE Transactions on Radiation and Plasma Medical Sciences}, number = {1}, publisher = {IEEE}, address = {New York, NY}, issn = {2469-7311}, doi = {10.1109/TRPMS.2022.3208615}, pages = {41 -- 51}, year = {2022}, abstract = {The concept of structure engineering has been proposed for exploring the next generation of radiation detectors with improved performance. A TOF-PET geometry with heterostructured scintillators with a pixel size of 3.0×3.1×15 mm3 was simulated using Monte Carlo. The heterostructures consisted of alternating layers of BGO as a dense material with high stopping power and plastic (EJ232) as a fast light emitter. The detector time resolution was calculated as a function of the deposited and shared energy in both materials on an event-by-event basis. While sensitivity was reduced to 32\% for 100 μm thick plastic layers and 52\% for 50 μm, the CTR distribution improved to 204±49 ps and 220±41 ps respectively, compared to 276 ps that we considered for bulk BGO. The complex distribution of timing resolutions was accounted for in the reconstruction. We divided the events into three groups based on their CTR and modeled them with different Gaussian TOF kernels. On a NEMA IQ phantom, the heterostructures had better contrast recovery in early iterations. On the other hand, BGO achieved a better contrast to noise ratio (CNR) after the 15th iteration due to the higher sensitivity. The developed simulation and reconstruction methods constitute new tools for evaluating different detector designs with complex time responses.}, language = {en} } @incollection{BauschatBennerKlingeetal.2022, author = {Bauschat, J.-Michael and Benner, Miriam and Klinge, Henner and Ziegler, Simon}, title = {Urbane Mobilit{\"a}t entdeckt die 3. Dimension}, series = {Transforming Mobility - What Next?}, booktitle = {Transforming Mobility - What Next?}, publisher = {Springer Gabler}, address = {Wiesbaden}, isbn = {978-3-658-36429-8}, doi = {10.1007/978-3-658-36430-4_53}, pages = {895 -- 916}, year = {2022}, abstract = {Der Themenkomplex urbane Mobilit{\"a}t ist getrieben durch den Verkehrsinfarkt in Ballungszentren, durch Luftverschmutzung und L{\"a}rm, sowie den Trend zum Leben in der Stadt in den st{\"a}dteplanerischen Fokus ger{\"u}ckt. Emissionsneutrale Antriebskonzepte in der Luftfahrt f{\"u}hren zu Ans{\"a}tzen Flugger{\"a}te einzusetzen, die batteriegetrieben vertikal aufsteigen und landen k{\"o}nnen. Flugphysikalisch und energetisch ist diese Technik nur dann sinnvoll, wenn es zwingende Gr{\"u}nde gibt (z.B. Rettungseins{\"a}tze), daher wird der flugphysikalische Hintergrund prinzipiell erl{\"a}utert. Es werden einige aktuelle Lufttransportkonzepte f{\"u}r eine urbane Personenbef{\"o}rderung vorgestellt. Sollte es verst{\"a}rkt zu Lufttransport {\"u}ber St{\"a}dten kommen, m{\"u}ssen betroffene Luftr{\"a}ume geordnet und {\"u}berwacht werden. Wie kompatibel Lufttransportsysteme mit den heute bereits relevanten urbanen Bef{\"o}rderungsmitteln sein m{\"u}ssen, wird kritisch diskutiert. Abschließend werden die Aspekte Akzeptanz durch die Kunden und Wirtschaftlichkeit ebenso angerissen, wie die hochproblematische Rohstoffgewinnung, die Entsorgung und das Recycling von Batterien.}, language = {de} } @article{CzarneckiBensbergAuth2019, author = {Czarnecki, Christian and Bensberg, Frank and Auth, Gunnar}, title = {Die Rolle von Softwarerobotern f{\"u}r die zuk{\"u}nftige Arbeitswelt}, series = {HMD Praxis der Wirtschaftsinformatik}, volume = {56}, journal = {HMD Praxis der Wirtschaftsinformatik}, number = {4}, publisher = {Springer}, address = {Cham}, issn = {2198-2775}, doi = {10.1365/s40702-019-00548-z}, pages = {795 -- 808}, year = {2019}, abstract = {Im Rahmen der Digitalisierung ist die zunehmende Automatisierung von bisher manuellen Prozessschritten ein Aspekt, der massive Auswirkungen auf die zuk{\"u}nftige Arbeitswelt haben wird. In diesem Kontext werden an den Einsatz von Softwarerobotern zur Prozessautomatisierung hohe Erwartungen gekn{\"u}pft. Bei den Implementierungsans{\"a}tzen wird die Diskussion aktuell insbesondere durch Robotic Process Automation (RPA) und Chatbots gepr{\"a}gt. Beide Ans{\"a}tze verfolgen das gemeinsame Ziel einer 1:1-Automatisierung von menschlichen Handlungen und dadurch ein direktes Ersetzen von Mitarbeitern durch Maschinen. Bei RPA werden Prozesse durch Softwareroboter erlernt und automatisiert ausgef{\"u}hrt. Dabei emulieren RPA-Roboter die Eingaben auf der bestehenden Pr{\"a}sentationsschicht, so dass keine {\"A}nderungen an vorhandenen Anwendungssystemen notwendig sind. Am Markt werden bereits unterschiedliche RPA-L{\"o}sungen als Softwareprodukte angeboten. Durch Chatbots werden Ein- und Ausgaben von Anwendungssystemen {\"u}ber nat{\"u}rliche Sprache realisiert. Dadurch ist die Automatisierung von unternehmensexterner Kommunikation (z. B. mit Kunden) aber auch von unternehmensinternen Assistenzt{\"a}tigkeiten m{\"o}glich. Der Beitrag diskutiert die Auswirkungen von Softwarerobotern auf die Arbeitswelt anhand von Anwendungsbeispielen und erl{\"a}utert die unternehmensindividuelle Entscheidung {\"u}ber den Einsatz von Softwarerobotern anhand von Effektivit{\"a}ts- und Effizienzzielen.}, language = {de} } @article{BensbergAuthCzarnecki2018, author = {Bensberg, Frank and Auth, Gunnar and Czarnecki, Christian}, title = {Einsatz von Text Analytics zur Unterst{\"u}tzung literaturintensiver Forschungsprozesse: Konzeption, Realisierung und Lessons Learned}, series = {Anwendungen und Konzepte der Wirtschaftsinformatik}, volume = {2018}, journal = {Anwendungen und Konzepte der Wirtschaftsinformatik}, number = {8}, publisher = {AKWI}, address = {Luzern}, issn = {2296-4592}, doi = {10.26034/lu.akwi.2018.3221}, pages = {1 -- 6}, year = {2018}, abstract = {Das anhaltende Wachstum wissenschaftlicher Ver{\"o}ffentlichungen wirft die Fragestellung auf, wie Literaturana-lysen im Rahmen von Forschungsprozessen digitalisiert und somit produktiver realisiert werden k{\"o}nnen. Insbesondere in informationstechnischen Fachgebieten ist die Forschungspraxis durch ein rasant wachsendes Publikationsaufkommen gekennzeichnet. Infolgedessen bietet sich der Einsatz von Methoden der Textanalyse (Text Analytics) an, die Textdaten automatisch vorbereiten und verarbeiten k{\"o}nnen. Erkenntnisse entstehen dabei aus Analysen von Wortarten und Subgruppen, Korrelations- sowie Zeitreihenanalysen. Dieser Beitrag stellt die Konzeption und Realisierung eines Prototypen vor, mit dem Anwender bibliographische Daten aus der etablierten Literaturdatenbank EBSCO Discovery Service mithilfe textanalytischer Methoden erschließen k{\"o}nnen. Der Prototyp basiert auf dem Analysesystem IBM Watson Explorer, das Hochschulen lizenzkostenfrei zur Verf{\"u}gung steht. Potenzielle Adressaten des Prototypen sind Forschungseinrichtungen, Beratungsunternehmen sowie Entscheidungstr{\"a}ger in Politik und Unternehmenspraxis.}, language = {de} } @article{CzarneckiWinkelmannSpiliopoulou2013, author = {Czarnecki, Christian and Winkelmann, Axel and Spiliopoulou, Myra}, title = {Referenzprozessabl{\"a}ufe f{\"u}r Telekommunikationsunternehmen: Eine Erweiterung des eTOM-Modells}, series = {Wirtschaftsinformatik}, volume = {55}, journal = {Wirtschaftsinformatik}, number = {2}, publisher = {Springer Fachmedien}, address = {Wiesbaden}, issn = {1861-8936}, doi = {10.1007/s11576-013-0351-9}, pages = {83 -- 97}, year = {2013}, abstract = {Der Telekommunikationsmarkt erf{\"a}hrt substanzielle Ver{\"a}nderungen. Neue Gesch{\"a}ftsmodelle, innovative Dienstleistungen und Technologien erfordern Reengineering, Transformation und Prozessstandardisierung. Mit der Enhanced Telecom Operation Map (eTOM) bietet das TM Forum ein international anerkanntes de facto Referenz-Prozess-Framework basierend auf spezifischen Anforderungen und Auspr{\"a}gungen der Telekommunikationsindustrie an. Allerdings enth{\"a}lt dieses Referenz-Framework nur eine hierarchische Sammlung von Prozessen auf unterschiedlichen Abstraktionsebenen. Eine Kontrollsicht verstanden als sequenzielle Anordnung von Aktivit{\"a}ten und daraus resultierend ein realer Prozessablauf fehlt ebenso wie eine Ende-zu-Ende-Sicht auf den Kunden. In diesem Artikel erweitern wir das eTOM-Referenzmodell durch Referenzprozessabl{\"a}ufe, in welchen wir das Wissen {\"u}ber Prozesse in Telekommunikationsunternehmen abstrahieren und generalisieren. Durch die Referenzprozessabl{\"a}ufe werden Unternehmen bei dem strukturierten und transparenten (Re-)Design ihrer Prozesse unterst{\"u}tzt. Wir demonstrieren die Anwendbarkeit und N{\"u}tzlichkeit unserer Referenzprozessabl{\"a}ufe in zwei Fallstudien und evaluieren diese anhand von Kriterien f{\"u}r die Bewertung von Referenzmodellen. Die Referenzprozessabl{\"a}ufe wurden vom TM Forum in den Standard aufgenommen und als Teil von eTOM Version 9 ver{\"o}ffentlicht. Dar{\"u}ber hinaus diskutieren wir die Komponenten unseres Ansatzes, die auch außerhalb der Telekommunikationsindustrie angewandt werden k{\"o}nnen.}, language = {de} }