@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} } @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} } @inproceedings{HueningWacheMagiera2021, author = {H{\"u}ning, Felix and Wache, Franz-Josef and Magiera, David}, title = {Redundant bus systems using dual-mode radio}, series = {Proceedings of Sixth International Congress on Information and Communication Technology}, booktitle = {Proceedings of Sixth International Congress on Information and Communication Technology}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-16-2379-0}, doi = {10.1007/978-981-16-2380-6_73}, pages = {835 -- 842}, year = {2021}, abstract = {Communication via serial bus systems, like CAN, plays an important role for all kinds of embedded electronic and mechatronic systems. To cope up with the requirements for functional safety of safety-critical applications, there is a need to enhance the safety features of the communication systems. One measure to achieve a more robust communication is to add redundant data transmission path to the applications. In general, the communication of real-time embedded systems like automotive applications is tethered, and the redundant data transmission lines are also tethered, increasing the size of the wiring harness and the weight of the system. A radio link is preferred as a redundant transmission line as it uses a complementary transmission medium compared to the wired solution and in addition reduces wiring harness size and weight. Standard wireless links like Wi-Fi or Bluetooth cannot meet the requirements for real-time capability with regard to bus communication. Using the new dual-mode radio enables a redundant transmission line meeting all requirements with regard to real-time capability, robustness and transparency for the data bus. In addition, it provides a complementary transmission medium with regard to commonly used tethered links. A CAN bus system is used to demonstrate the redundant data transfer via tethered and wireless CAN.}, language = {en} } @inproceedings{KloeserKohlKraftetal.2021, author = {Kl{\"o}ser, Lars and Kohl, Philipp and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {Multi-attribute relation extraction (MARE): simplifying the application of relation extraction}, series = {Proceedings of the 2nd International Conference on Deep Learning Theory and Applications - DeLTA}, booktitle = {Proceedings of the 2nd International Conference on Deep Learning Theory and Applications - DeLTA}, isbn = {978-989-758-526-5}, doi = {10.5220/0010559201480156}, pages = {148 -- 156}, year = {2021}, abstract = {Natural language understanding's relation extraction makes innovative and encouraging novel business concepts possible and facilitates new digitilized decision-making processes. Current approaches allow the extraction of relations with a fixed number of entities as attributes. Extracting relations with an arbitrary amount of attributes requires complex systems and costly relation-trigger annotations to assist these systems. We introduce multi-attribute relation extraction (MARE) as an assumption-less problem formulation with two approaches, facilitating an explicit mapping from business use cases to the data annotations. Avoiding elaborated annotation constraints simplifies the application of relation extraction approaches. The evaluation compares our models to current state-of-the-art event extraction and binary relation extraction methods. Our approaches show improvement compared to these on the extraction of general multi-attribute relations.}, language = {en} } @inproceedings{MandekarJentschLutzetal.2021, author = {Mandekar, Swati and Jentsch, Lina and Lutz, Kai and Behbahani, Mehdi and Melnykowycz, Mark}, title = {Earable design analysis for sleep EEG measurements}, series = {UbiComp '21}, booktitle = {UbiComp '21}, doi = {10.1145/3460418.3479328}, pages = {171 -- 175}, year = {2021}, abstract = {Conventional EEG devices cannot be used in everyday life and hence, past decade research has been focused on Ear-EEG for mobile, at-home monitoring for various applications ranging from emotion detection to sleep monitoring. As the area available for electrode contact in the ear is limited, the electrode size and location play a vital role for an Ear-EEG system. In this investigation, we present a quantitative study of ear-electrodes with two electrode sizes at different locations in a wet and dry configuration. Electrode impedance scales inversely with size and ranges from 450 kΩ to 1.29 MΩ for dry and from 22 kΩ to 42 kΩ for wet contact at 10 Hz. For any size, the location in the ear canal with the lowest impedance is ELE (Left Ear Superior), presumably due to increased contact pressure caused by the outer-ear anatomy. The results can be used to optimize signal pickup and SNR for specific applications. We demonstrate this by recording sleep spindles during sleep onset with high quality (5.27 μVrms).}, language = {en} } @inproceedings{KohlSchmidtsKloeseretal.2021, author = {Kohl, Philipp and Schmidts, Oliver and Kl{\"o}ser, Lars and Werth, Henri and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {STAMP 4 NLP - an agile framework for rapid quality-driven NLP applications development}, series = {Quality of Information and Communications Technology. QUATIC 2021}, booktitle = {Quality of Information and Communications Technology. QUATIC 2021}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-85346-4}, doi = {10.1007/978-3-030-85347-1_12}, pages = {156 -- 166}, year = {2021}, abstract = {The progress in natural language processing (NLP) research over the last years, offers novel business opportunities for companies, as automated user interaction or improved data analysis. Building sophisticated NLP applications requires dealing with modern machine learning (ML) technologies, which impedes enterprises from establishing successful NLP projects. Our experience in applied NLP research projects shows that the continuous integration of research prototypes in production-like environments with quality assurance builds trust in the software and shows convenience and usefulness regarding the business goal. We introduce STAMP 4 NLP as an iterative and incremental process model for developing NLP applications. With STAMP 4 NLP, we merge software engineering principles with best practices from data science. Instantiating our process model allows efficiently creating prototypes by utilizing templates, conventions, and implementations, enabling developers and data scientists to focus on the business goals. Due to our iterative-incremental approach, businesses can deploy an enhanced version of the prototype to their software environment after every iteration, maximizing potential business value and trust early and avoiding the cost of successful yet never deployed experiments.}, language = {en} } @inproceedings{SchmidtsKraftWinkensetal.2021, author = {Schmidts, Oliver and Kraft, Bodo and Winkens, Marvin and Z{\"u}ndorf, Albert}, title = {Catalog integration of heterogeneous and volatile product data}, series = {DATA 2020: Data Management Technologies and Applications}, booktitle = {DATA 2020: Data Management Technologies and Applications}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-83013-7}, doi = {10.1007/978-3-030-83014-4_7}, pages = {134 -- 153}, year = {2021}, abstract = {The integration of frequently changing, volatile product data from different manufacturers into a single catalog is a significant challenge for small and medium-sized e-commerce companies. They rely on timely integrating product data to present them aggregated in an online shop without knowing format specifications, concept understanding of manufacturers, and data quality. Furthermore, format, concepts, and data quality may change at any time. Consequently, integrating product catalogs into a single standardized catalog is often a laborious manual task. Current strategies to streamline or automate catalog integration use techniques based on machine learning, word vectorization, or semantic similarity. However, most approaches struggle with low-quality or real-world data. We propose Attribute Label Ranking (ALR) as a recommendation engine to simplify the integration process of previously unknown, proprietary tabular format into a standardized catalog for practitioners. We evaluate ALR by focusing on the impact of different neural network architectures, language features, and semantic similarity. Additionally, we consider metrics for industrial application and present the impact of ALR in production and its limitations.}, language = {en} } @inproceedings{GrundmannBauerBodenetal.2019, author = {Grundmann, Jan Thimo and Bauer, Waldemar and Boden, Ralf Christian and Ceriotti, Matteo and Cordero, Federico and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Hercik, D. and Herique, A. and Ho, Tra-Mi and Jahnke, Rico and Kofman, Wlodek and Lange, Caroline and Lichtenheldt, Roy and McInnes, Colin R. and Mikschl, Tobias and Mikulz, Eugen and Montenegro, Sergio and Moore, Iain and Pelivan, Ivanka and Peloni, Alessandro and Plettemeier, Dirk and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Riemann, Johannes and Rogez, Yves and Ruffer, Michael and Sasaki, Kaname and Schmitz, Nicole and Seboldt, Wolfgang and Seefeldt, Patric and Spietz, Peter and Spr{\"o}witz, Tom and Sznajder, Maciej and Toth, Norbert and Viavattene, Giulia and Wejmo, Elisabet and Wolff, Friederike and Ziach, Christian}, title = {Responsive integrated small spacecraft solar sail and payload design concepts and missions}, series = {Conference: 5th International Symposium on Solar Sailing (ISSS 2019)}, booktitle = {Conference: 5th International Symposium on Solar Sailing (ISSS 2019)}, year = {2019}, abstract = {Asteroid mining has the potential to greatly reduce the cost of in-space manufacturing, production of propellant for space transportation and consumables for crewed spacecraft, compared to launching the required resources from Earth's deep gravity well. This paper discusses the top-level mission architecture and trajectory design for these resource-return missions, comparing high-thrust trajectories with continuous low-thrust solar-sail trajectories. This work focuses on maximizing the economic Net Present Value, which takes the time-cost of finance into account and therefore balances the returned resource mass and mission duration. The different propulsion methods will then be compared in terms of maximum economic return, sets of attainable target asteroids, and mission flexibility. This paper provides one more step towards making commercial asteroid mining an economically viable reality by integrating trajectory design, propulsion technology and economic modelling.}, language = {en} } @inproceedings{GrundmannBauerBieleetal.2018, author = {Grundmann, Jan Thimo and Bauer, Waldemar and Biele, Jens and Boden, Ralf and Ceriotti, Matteo and Cordero, Federico and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Herč{\´i}k, David and Ho, Tra-Mi and Jahnke, Rico and Koch, Aaron D and Koncz, Alexander and Krause, Christian and Lange, Caroline and Lichtenheldt, Roy and Maiwald, Volker and Mikschl, Tobias and Mikulz, Eugen and Montenegro, Sergio and Pelivan, Ivanka and Peloni, Alessandro and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Riemann, Johannes and Ruffer, Michael and Sasaki, Kaname and Schmitz, Nicole and Seboldt, Wolfgang and Seefeldt, Patric and Spietz, Peter and Spr{\"o}witz, Tom and Sznajder, Maciej and Tardivel, Simon and T{\´o}th, Norbert and Wejmo, Elisabet and Wolff, Friederike and Ziach, Christian}, title = {Small spacecraft based multiple near-earth asteroid rendezvous and landing with near-term solar sails and 'Now-Term 'technologies}, series = {69 th International Astronautical Congress (IAC)}, booktitle = {69 th International Astronautical Congress (IAC)}, pages = {1 -- 18}, year = {2018}, abstract = {Physical interaction with small solar system bodies (SSSB) is the next step in planetary science, planetary in-situ resource utilization (ISRU), and planetary defense (PD). It requires a broader understanding of the surface properties of the target objects, with particular interest focused on those near Earth. Knowledge of composition, multi-scale surface structure, thermal response, and interior structure is required to design, validate and operate missions addressing these three fields. The current level of understanding is occasionally simplified into the phrase, "If you've seen one asteroid, you've seen one asteroid", meaning that the in-situ characterization of SSSBs has yet to cross the threshold towards a robust and stable scheme of classification. This would enable generic features in spacecraft design, particularly for ISRU and science missions. Currently, it is necessary to characterize any potential target object sufficiently by a dedicated pre-cursor mission to design the mission which then interacts with the object in a complex fashion. To open up strategic approaches, much broader in-depth characterization of potential target objects would be highly desirable. In SSSB science missions, MASCOT-like nano-landers and instrument carriers which integrate at the instrument level to their mothership have met interest. By its size, MASCOT is compatible with small interplanetary missions. The DLR-ESTEC Gossamer Roadmap Science Working Groups' studies identified Multiple Near-Earth asteroid (NEA) Rendezvous (MNR) as one of the space science missions only feasible with solar sail propulsion. The Solar Polar Orbiter (SPO) study showed the ability to access any inclination, theDisplaced-L1 (DL1) mission operates close to Earth, where objects of interest to PD and for ISRU reside. Other studies outline the unique capability of solar sails to provide access to all SSSB, at least within the orbit of Jupiter, and significant progress has been made to explore the performance envelope of near-term solar sails for MNR. However, it is difficult for sailcraft to interact physically with a SSSB. We expand and extend the philosophy of the recently qualified DLR Gossamer solar sail deployment technology using efficient multiple sub-spacecraft integration to also include landers for one-way in-situ investigations and sample-return missions by synergetic integration and operation of sail and lander. The MASCOT design concept and its characteristic features have created an ideal counterpart for thisand has already been adapted to the needs of the AIM spacecraft, former part of the NASA-ESA AIDA missionDesigning the 69th International Astronautical Congress (IAC), Bremen, Germany, 1-5 October 2018. IAC-18-F1.2.3 Page 2 of 17 combined spacecraft for piggy-back launch accommodation enables low-cost massively parallel access to the NEA population.}, language = {en} }