@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}
}
@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}
}
@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}
}
@article{EngemannCoenenDawaretal.2021,
  author    = {Engemann, Heiko and C{\"o}nen, Patrick and Dawar, Harshal and Du, Shengzhi and Kallweit, Stephan},
  title     = {A robot-assisted large-scale inspection of wind turbine blades in manufacturing using an autonomous mobile manipulator},
  series = {Applied Sciences},
  volume    = {11},
  journal   = {Applied Sciences},
  number    = {19},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2076-3417},
  doi       = {10.3390/app11199271},
  pages     = {1 -- 22},
  year      = {2021},
  abstract  = {Wind energy represents the dominant share of renewable energies. The rotor blades of a wind turbine are typically made from composite material, which withstands high forces during rotation. The huge dimensions of the rotor blades complicate the inspection processes in manufacturing. The automation of inspection processes has a great potential to increase the overall productivity and to create a consistent reliable database for each individual rotor blade. The focus of this paper is set on the process of rotor blade inspection automation by utilizing an autonomous mobile manipulator. The main innovations include a novel path planning strategy for zone-based navigation, which enables an intuitive right-hand or left-hand driving behavior in a shared human-robot workspace. In addition, we introduce a new method for surface orthogonal motion planning in connection with large-scale structures. An overall execution strategy controls the navigation and manipulation processes of the long-running inspection task. The implemented concepts are evaluated in simulation and applied in a real-use case including the tip of a rotor blade form.},
  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}
}
@article{SchuellerRuhlDinstuehlerSengeretal.2022,
  author    = {Sch{\"u}ller-Ruhl, Aaron and Dinst{\"u}hler, Leonard and Senger, Thorsten and Bergfeld, Stefan and Ingenhag, Christian and Fleischhaker, Robert},
  title     = {Direct fabrication of arbitrary phase masks in optical glass via ultra-short pulsed laser writing of refractive index modifications},
  series = {Applied Physics B},
  volume    = {128},
  journal   = {Applied Physics B},
  number    = {Article number: 208},
  editor    = {Mackenzie, Jacob},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1432-0649 (Online)},
  doi       = {10.1007/s00340-022-07928-2},
  pages     = {1 -- 11},
  year      = {2022},
  abstract  = {We study the possibility to fabricate an arbitrary phase mask in a one-step laser-writing process inside the volume of an optical glass substrate. We derive the phase mask from a Gerchberg-Saxton-type algorithm as an array and create each individual phase shift using a refractive index modification of variable axial length. We realize the variable axial length by superimposing refractive index modifications induced by an ultra-short pulsed laser at different focusing depth. Each single modification is created by applying 1000 pulses with 15 μJ pulse energy at 100 kHz to a fixed spot of 25 μm diameter and the focus is then shifted axially in steps of 10 μm. With several proof-of-principle examples, we show the feasibility of our method. In particular, we identify the induced refractive index change to about a value of Δn=1.5⋅10-3. We also determine our current limitations by calculating the overlap in the form of a scalar product and we discuss possible future improvements.},
  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}
}