TY - JOUR A1 - Molloy, Dara A1 - Müller, Patrick A1 - Deegan, Brian A1 - Mullins, Darragh A1 - Horgan, Jonathan A1 - Ward, Enda A1 - Jones, Edward A1 - Braun, Alexander A1 - Glavin, Martin T1 - Analysis of the Impact of Lens Blur on Safety-Critical Automotive Object Detection JF - IEEE Access N2 - Camera-based object detection is widely used in safety-critical applications such as advanced driver assistance systems (ADAS) and autonomous vehicle research. Road infrastructure has been designed for human vision, so computer vision, with RGB cameras, is a vital source of semantic information from the environment. Sensors, such as LIDAR and RADAR, are also often utilized for these applications; however, cameras provide a higher spatial resolution and color information. The spatial frequency response (SFR), or sharpness of a camera, utilized in object detection systems must be sufficient to allow a detection algorithm to localize objects in the environment over its lifetime reliably. This study explores the relationship between object detection performance and SFR. Six state-of-the-art object detection models are evaluated with varying levels of lens defocus. A novel raw image dataset is created and utilized, containing pedestrians and cars over a range of distances up to 100-m from the sensor. Object detection performance for each defocused dataset is analyzed over a range of distances to determine the minimum SFR necessary in each case. Results show that the relationship between object detection performance and lens blur is much more complex than previous studies have found due to lens field curvature, chromatic aberration, and astigmatisms. We have found that smaller objects are disproportionately impacted by lens blur, and different object detection models have differing levels of robustness to lens blur KW - DOAJ KW - Object detection KW - intelligent transportation system KW - autonomous vehicles KW - ADAS KW - lens blur Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-42999 SN - 2169-3536 VL - 12 SP - 3554 EP - 3569 PB - IEEE ER - TY - JOUR A1 - Geerkens, Simon A1 - Sieberichs, Christian A1 - Braun, Alexander A1 - Waschulzik, Thomas T1 - QI²: an interactive tool for data quality assurance JF - AI and Ethics N2 - The importance of high data quality is increasing with the growing impact and distribution of ML systems and big data. Also, the planned AI Act from the European commission defines challenging legal requirements for data quality especially for the market introduction of safety relevant ML systems. In this paper, we introduce a novel approach that supports the data quality assurance process of multiple data quality aspects. This approach enables the verification of quantitative data quality requirements. The concept and benefits are introduced and explained on small example data sets. How the method is applied is demonstrated on the well-known MNIST data set based an handwritten digits. KW - Performance metrics KW - HSD Publikationsfonds KW - DEAL KW - DFG Publikationskosten KW - Machine learning KW - Quality assurance KW - Data integrity KW - Data quality Y1 - 2024 U6 - https://doi.org/10.1007/s43681-023-00390-6 SN - 2730-5961 N1 - Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 532148125 and supported by the central publication fund of Hochschule Düsseldorf University of Applied Sciences Data availability declaration: The data that support the findings of this scientific publication are available from the corresponding author upon reasonable request. PB - Springer Nature ER - TY - JOUR A1 - Sieberichs, Christian A1 - Geerkens, Simon A1 - Braun, Alexander A1 - Waschulzik, Thomas T1 - ECS: an interactive tool for data quality assurance JF - AI and Ethics N2 - With the increasing capabilities of machine learning systems and their potential use in safety-critical systems, ensuring high-quality data is becoming increasingly important. In this paper, we present a novel approach for the assurance of data quality. For this purpose, the mathematical basics are first discussed and the approach is presented using multiple examples. This results in the detection of data points with potentially harmful properties for the use in safety-critical systems. KW - DEAL KW - HSD Publikationsfonds KW - Data visulization KW - Distance based KW - Data quality assurance KW - Equivalence class sets KW - DFG Publikationskosten Y1 - 2024 U6 - https://doi.org/10.1007/s43681-023-00393-3 SN - 2730-5961 N1 - Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 532148125 and supported by the central publication fund of Hochschule Düsseldorf University of Applied Sciences Data availability declaration: All data that support the findings of this scientific publication are available within this paper and/or its supplementary information files/materials. Otherwise: The data that support the findings of this scientific publication are available from the corresponding author upon reasonable request. PB - Springer Nature ER - TY - PAT A1 - Braun, Alexander A1 - Richwin, Matthias A1 - Weber, Thomas T1 - Optoelektronische Sensoreinrichtung für ein Kraftfahrzeug N2 - Beschrieben wird eine optoelektronische Sensoreinrichtung für ein Kraftfahrzeug zur unterscheidenden Detektion von Feuchtigkeit und Salzlösungen auf einer Fahrzeugscheibe, mit einer Beleuchtungseinheit zur Einstrahlung von Licht in eine Fahrzeugscheibe und mit einem Lichtempfänger, welcher von der Fahrzeugscheibe reflektiertes Licht erfasst, sowie mit einem Koppelelement zur Ein- und Auskopplung von Licht in bzw. aus der Fahrzeugscheibe, wobei die Beleuchtungseinrichtung Licht über einen Einfallswinkelbereich in die Fahrzeugscheibe einstrahlt, der sich über mehrere Winkelgrade erstreckt, wobei der Lichtempfänger eine Vielzahl von Empfangselementen aufweist, wobei ein optisches System das von der Fahrzeugscheibe in einen Ausfallswinkelbereich reflektierte Licht auf Empfangselemente des Lichtempfängers abbildet und wobei der Lichtempfänger ein Signal generiert, aus dem eine Auswertevorrichtung den Grenzwinkel der Totalreflexion an der Fahrzeugscheibe ermittelt. Y1 - 2009 UR - https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102007052704A1 PB - Deutsches Patent- und Markenamt ER - TY - INPR A1 - Geerkens, Simon A1 - Sieberichs, Christian A1 - Braun, Alexander A1 - Waschulzik, Thomas T1 - QI2 -- an Interactive Tool for Data Quality Assurance N2 - The importance of high data quality is increasing with the growing impact and distribution of ML systems and big data. Also the planned AI Act from the European commission defines challenging legal requirements for data quality especially for the market introduction of safety relevant ML systems. In this paper we introduce a novel approach that supports the data quality assurance process of multiple data quality aspects. This approach enables the verification of quantitative data quality requirements. The concept and benefits are introduced and explained on small example data sets. How the method is applied is demonstrated on the well known MNIST data set based an handwritten digits. KW - Data Structures and Algorithms KW - Machine Learning KW - Computers and Society KW - Artificial Intelligence Y1 - 2023 CY - arXiv ER - TY - JOUR A1 - Wolf, Dominik Werner A1 - Ulrich, Markus A1 - Braun, Alexander T1 - Novel developments of refractive power measurement techniques in the automotive world JF - Metrologia N2 - Refractive power measurements serve as the primary quality standard in the automotive glazing industry. In the light of autonomous driving new optical metrics are becoming more and more popular for specifying optical quality requirements for the windshield. Nevertheless, the link between those quantities and the refractive power needs to be established in order to ensure a holistic requirement profile for the windshield. As a consequence, traceable high-resolution refractive power measurements are still required for the glass quality assessment. Standard measurement systems using Moiré patterns for refractive power monitoring in the automotive industry are highly resolution limited, wherefore they are insufficient for evaluating the camera window area. Consequently, there is a need for more sophisticated refractive power measurement systems that provide a higher spatial resolution. In addition, a calibration procedure has to be developed in order to guarantee for comparability of the measurement results. For increasing the resolution, a measurement setup based on an auto-correlation algorithm is tested in this paper. Furthermore, a calibration procedure is established by using a single reference lens with a nominal refractive power of 100 km-1. For the calibration of the entire measurement range of the system, the lens is tilted by an inclination angle orthogonal to the optical axis. The effective refractive power is then given by the Kerkhof model. By adopting the measurement and calibration procedure presented in this paper, glass suppliers in the automotive industry will be able to detect relevant manufacturing defects within the camera window area more accurately paving the way for a holistic quality assurance of the windshield for future advanced driver-assistance system (ADAS) functionalities. Concurrently, the traceability of the measurement results is ensured by establishing a calibration chain based on a single reference lens, which is traced back to international standards. Y1 - 2023 UR - http://iopscience.iop.org/article/10.1088/1681-7575/acf1a4 U6 - https://doi.org/10.1088/1681-7575/acf1a4 SN - 1681-7575 IS - ACCEPTED MANUSCRIPT PB - IOP Publishing ER - TY - CHAP A1 - Müller, Patrick A1 - Braun, Alexander A1 - Keuper, Margret T1 - Impact of realistic properties of the point spread function on classification tasks to reveal a possible distribution shift T2 - NeurIPS 2022: Workshop on Distribution Shifts: Connecting Methods and Applications, December 3rd, 2022, New Orleans, USA KW - chromatic aberration KW - corruption KW - Deep Neural Networks KW - Distribution Shift KW - MTF Y1 - 2022 UR - https://openreview.net/forum?id=r7WJpE3oy0 CY - New Orleans ER - TY - INPR A1 - Sieberichs, Christian A1 - Geerkens, Simon A1 - Braun, Alexander A1 - Waschulzik, Thomas T1 - ECS -- an Interactive Tool for Data Quality Assurance N2 - With the increasing capabilities of machine learning systems and their potential use in safety-critical systems, ensuring high-quality data is becoming increasingly important. In this paper we present a novel approach for the assurance of data quality. For this purpose, the mathematical basics are first discussed and the approach is presented using multiple examples. This results in the detection of data points with potentially harmful properties for the use in safety-critical systems. KW - Artificial Intelligence KW - Machine Learning KW - PrePrint KW - Systems and Control Y1 - 2023 U6 - https://doi.org/10.48550/arXiv.2307.04368 PB - arXiv ER - TY - CHAP A1 - Müller, Patrick A1 - Braun, Alexander T1 - Simulating optical properties to access novel metrological parameter ranges and the impact of different model approximations T2 - 2022 IEEE International Workshop on Metrology for Automotive (MetroAutomotive), 4-6 July 2022 Y1 - 2022 SN - 978-1-6654-6689-9 U6 - https://doi.org/10.1109/MetroAutomotive54295.2022.9855079 SP - 133 EP - 138 PB - IEEE ER - TY - JOUR A1 - Müller, Patrick A1 - Braun, Alexander T1 - Local performance evaluation of AI-algorithms with the generalized spatial recall index JF - tm - Technisches Messen Y1 - 2023 U6 - https://doi.org/10.1515/teme-2023-0013 SN - 2196-7113 VL - 90 IS - 7-8 SP - 464 EP - 477 PB - de Gruyter ER - TY - JOUR A1 - Müller, Patrick A1 - Braun, Alexander T1 - MTF as a performance indicator for AI algorithms? JF - Electronic Imaging: Society for Imaging Science and Technology N2 - Abstract The modulation-transfer function (MTF) is a fundamental optical metric to measure the optical quality of an imaging system. In the automotive industry it is used to qualify camera systems for ADAS/AD. Each modern ADAS/AD system includes evaluation algorithms for environment perception and decision making that are based on AI/ML methods and neural networks. The performance of these AI algorithms is measured by established metrics like Average Precision (AP) or precision-recall-curves. In this article we research the robustness of the link between the optical quality metric and the AI performance metric. A series of numerical experiments were performed with object detection and instance segmentation algorithms (cars, pedestrians) evaluated on image databases with varying optical quality. We demonstrate with these that for strong optical aberrations a distinct performance loss is apparent, but that for subtle optical quality differences – as might arise during production tolerances – this link does not exhibit a satisfactory correlation. This calls into question how reliable the current industry practice is where a produced camera is tested end-of-line (EOL) with the MTF, and fixed MTF thresholds are used to qualify the performance of the camera-under-test. KW - AI performance metrics KW - Artificial Intelligence KW - Modulation Transfer Function (MTF) KW - Optical Quality KW - Perception Y1 - 2023 U6 - https://doi.org/10.2352/EI.2023.35.16.AVM-125 SN - 2470-1173 VL - 35 IS - 16 SP - 1 EP - 7 PB - Society for Imaging Sciences and Technology ER - TY - CHAP A1 - Tischbein, Franziska A1 - Fatemi, Armin A1 - Wirtz, Frank A1 - Schmoger, Christin A1 - Dorendorf, Stefan A1 - Schurtz, Annika A1 - Echternacht, David A1 - Ulbig, Andreas T1 - Development of Strategies for the Smartification of Low-Voltage Grids T2 - ETG-Fb. 170: ETG Kongress 2023 : Die Energiewende beschleunigen, 25. – 26.05.2023 in Kasse Y1 - 2023 SN - 978-3-8007-6108-1 VL - ETG-Fachberichte 170 SP - 438 EP - 444 PB - VDE CY - Berlin ER - TY - CHAP A1 - Langmann, Reinhard A1 - Stiller, Michael ED - Auer, Michel E. ED - Zutin, Danilo G. T1 - Cloud-based industrial control services - The next generation PLC? T2 - Online Engineering & Internet of Things: Proceedings of the 14th International Conference on Remote Engineering and Virtual Instrumentation REV 2017, held 15–17 March 2017, Columbia University, New York, USA Y1 - 2017 SN - 978-3-319-64351-9 U6 - https://doi.org/10.1007/978-3-319-64352-6_1 SN - 2190-4111 VL - Lecture Notes in Networks and Systems : 22 SP - 3 EP - 18 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Schwung, Dorothea A1 - Yuwono, Steve A1 - Schwung, Andreas A1 - Ding, Steven X. T1 - PLC-Informed Distributed Game Theoretic Learning of Energy-Optimal Production Policies JF - IEEE Transactions on Cybernetics Y1 - 2022 U6 - https://doi.org/10.1109/TCYB.2022.3179950 SN - 2168-2267 SP - 1 EP - 14 PB - IEEE ER - TY - JOUR A1 - Queval, Loic A1 - Sotelo, Guilherme G. A1 - Kharmiz, Yassin A1 - Dias, Daniel H. N. A1 - Sass, Felipe A1 - Zermeno, Victor M. R. A1 - Gottkehaskamp, Raimund T1 - Optimization of the Superconducting Linear Magnetic Bearing of a Maglev Vehicle JF - IEEE Transactions on Applied Superconductivity KW - High temperature superconductors KW - linear magnetic bearing KW - maglev system KW - stochastic optimization KW - superconductor modeling Y1 - 2016 U6 - https://doi.org/10.1109/TASC.2016.2528989 SN - 1051-8223 VL - 26 IS - 3 PB - IEEE ER - TY - JOUR A1 - Langmann, Reinhard A1 - Michael, Stiller T1 - The PLC as a Smart Service in Industry 4.0 Production System JF - Applied Sciences Y1 - 2019 U6 - https://doi.org/10.3390/app9183815 SN - 2076-3417 VL - 9 IS - 18 PB - MDPI ER - TY - JOUR A1 - Echternacht, David A1 - Linnemann, Christian A1 - Drees, Tim A1 - Breuer, Christopher A1 - Moser, Albert T1 - Wechselwirkungen zwischen Druckluftspeichern und Netzengpässen in zukünftigen Energiesystemen JF - Solarzeitalter : Politik, Kultur und Ökonomie erneuerbarer Energien Y1 - 2013 VL - 25 IS - 1 SP - 54 EP - 59 PB - EUROSOLAR Verl. ER - TY - CHAP A1 - Becker, Andreas A1 - Loges, Hauke A1 - Kippelt, Stefan A1 - Gitis, Alexander A1 - Merei, Ghada A1 - Echternacht, David A1 - Müller, Marcus A1 - Zeh, Alexander A1 - Kleimaier, Martin A1 - Leuthold, Matthias A1 - Hesse, Holger C. A1 - Beck, Hans-Peter A1 - Engel, Bernd A1 - Jossen, Andreas A1 - Moser, Albert A1 - Rehtanz, Christian A1 - Sauer, Dirk-Uwe A1 - Witzmann, Rolf T1 - Electricity Storage Systems in Medium- and Low-Voltage Networks T2 - Proceedings of International ETG Congress 2015: Die Energiewende - blueprints for the new energy age : date: 17-18 Nov. 2015 Y1 - 2015 SN - 9783800741212 SP - 151 EP - 158 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Breuer, Christopher A1 - Drees, Tim A1 - Echternacht, David A1 - Linnemann, Christian A1 - Moser, Albert T1 - Identification of potentials and locations for power-to-gas in germany T2 - 6. EUROSOLAR-Konferenz "Stadtwerke mit erneuerbaren Energien", 21.-22. Juni 2012, Heidelberg Y1 - 2012 SN - 978-3-00-037648-1 PB - Eurosolar CY - Berlin ER - TY - GEN A1 - Breuer, Christopher A1 - Drees, Tim A1 - Echternacht, David A1 - Linnemann, Christian A1 - Moser, Albert T1 - Standorte und Potenziale für Power-to-Gas T2 - e|m|w Y1 - 2012 UR - https://www.emw-online.com/artikel/182128/spitzenkappung-erfordert-intelligente-netzsteuerung IS - 4 PB - Energate ER - TY - CHAP A1 - Breuer, Christopher A1 - Echternacht, David A1 - Linnemann, Christian A1 - Moser, Albert T1 - Technical and economic comparison of national and joint cross-border curative congestion management application T2 - 2011 8th International Conference on the European Energy Market (EEM), 25.05.2011 - 27.05.2011, Zagreb, Croatia Y1 - 2011 UR - http://ieeexplore.ieee.org/document/5952974/ SN - 978-1-61284-285-1 U6 - https://doi.org/10.1109/EEM.2011.5952974 SP - 33 EP - 38 PB - IEEE ER - TY - GEN A1 - Breuer, Christopher A1 - Echternacht, David A1 - Linnemann, Christian A1 - Moser, Albert T1 - Der Norden und der Osten brauchen Windgas T2 - E 21-Magazin : Energie für morgen Y1 - 2012 IS - 2 SP - 46 EP - 47 PB - Energate ER - TY - BOOK A1 - Buchholz, B. A1 - Jeromin, I. A1 - Asgarieh, L. A1 - Echternacht, David A1 - Fan, M. A1 - Repo, S. A1 - Dedekind, K. A1 - Ma, Z. A1 - Gramme, E. T1 - Asset management for distribution networks with high penetration of distributed energy resources Y1 - 2018 CY - Cigré ER - TY - THES A1 - Echternacht, David T1 - Optimierte Positionierung von Messtechnik zur Zustandsschätzung in Verteilnetzen. Zugl.: Aachen, Techn. Hochsch., Diss., 2014 T2 - Aachener Beiträge zur Energieversorgung Y1 - 2015 UR - http://d-nb.info/1066589119/04 SN - 9783941704480 PB - Printproduction Wolff CY - Aachen ER - TY - GEN A1 - Echternacht, David T1 - Spitzenkappung erfordert intelligente Netzsteuerung T2 - e|m|w Y1 - 2018 UR - https://www.emw-online.com/artikel/182128/spitzenkappung-erfordert-intelligente-netzsteuerung IS - 2 PB - Energate ER - TY - CHAP A1 - Echternacht, David A1 - Eickmann, Jonas A1 - Moser, Albert T1 - Quantifizierung des Nutzens von Smart Metern zur Zustandsschätzung in der Verteilnetzebene T2 - Innehalten und Ausblick: Effektivität und Effizienz für die Energiewende / 13. Symposium Energieinnovation, 12. - 14. Februar 2014, TU Graz Y1 - 2014 UR - https://www.tugraz.at/fileadmin/user_upload/Events/Eninnov2014/files/kf/KF_Eickmann_Smart.pdf PB - TU Graz CY - Graz ER - TY - CHAP A1 - Echternacht, David A1 - Feilhauer, Werner A1 - Franken, Muriel A1 - Geulen, Uwe A1 - Moser, Albert A1 - Schrieder, Werner A1 - Zimmer, Peter T1 - Smart Area Aachen - Zustandsschätzung in Verteilnetzen T2 - Von Smart Grids zu Smart Markets 2015 - Beiträge der ETG-Fachtagung 25.03.2015 - 26.03.2015 in Kassel, Deutschland Y1 - 2015 PB - ETG CY - Kassel ER - TY - CHAP A1 - Echternacht, David A1 - El Haouati, I. A1 - Schermuly, Rainer A1 - Meyer, F. ED - Schulz, Detlef T1 - Simulating the impact of e-mobility charging infrastructure on urban low-voltage networks. Postersession T2 - NEIS 2018: Conference on Sustainable Energy Supply and Energy Storage Systems. Hamburg, Deutschland, 20.09.-21.09.2018 Y1 - 2018 SN - 978-3-8007-4821-1 SP - 208 EP - 213 PB - VDE CY - Frankfurt am Main; Piscataway, NJ ER - TY - CHAP A1 - Echternacht, David A1 - Fellhauer, W. A1 - Geulen, Uwe A1 - Schrieder, Werner A1 - Zimmer, Peter T1 - Smart Area Aachen - State Estimation in Distribution Grids T2 - Worls Smart Grid Forum 2013, Berlin, 23-25 September 2013 Y1 - 2013 SP - 1 EP - 6 CY - Berlin ER - TY - CHAP A1 - Echternacht, David A1 - Franken, Muriel A1 - Moser, Albert A1 - Geulen, Uwe A1 - Zimmer, Peter A1 - Feilhauer, Werner A1 - Schrieder, W. T1 - Smart Area Aachen - in field test of meter placement and state estimation algorithms for distribution grids T2 - 2015 IEEE PES Innovative Smart Grid Technologies Latin America (ISGT LATAM), 05.10.2015 - 07.10.2015, Montevideo Y1 - 2015 UR - http://ieeexplore.ieee.org/document/7381194/ SN - 978-1-4673-6605-2 U6 - https://doi.org/10.1109/ISGT-LA.2015.7381194 SP - 435 EP - 439 PB - IEEE ER - TY - CHAP A1 - Echternacht, David A1 - Heuberger, Daniel A1 - Breuer, Christopher A1 - Linnemann, Christian A1 - Moser, Albert T1 - Advantageous positions for HVDC terminals in Europe T2 - 2013 IEEE Energytech, 21.05.2013 - 23.05.2013, Cleveland Y1 - 2013 UR - http://ieeexplore.ieee.org/document/6645291/ SN - 978-1-4673-4444-9 U6 - https://doi.org/10.1109/EnergyTech.2013.6645291 SP - 1 EP - 5 PB - IEEE ER - TY - CHAP A1 - Echternacht, David A1 - Kleimaier, Martin A1 - Moser, Albert T1 - Kostenoptimale Positionierung von Messtechnik zur Zustandsschätzung in der Verteilnetzebene unter Berücksichtigung stochastisch abhängiger Messfehler T2 - Internationaler ETG-Kongress 2013 - Energieversorgung auf dem Weg nach 2050 - Symposium 1: Security in Critical Infrastructures Today 11/05/2013 - 11/06/2013, Berlin Y1 - 2013 SP - 1 EP - 8 PB - VDE CY - Berlin ER - TY - CHAP A1 - Echternacht, David A1 - Linnemann, Christian A1 - Drees, Tim A1 - Breuer, Christopher A1 - Moser, Albert ED - EUROSOLAR and the World Council for Renewable Energy, T1 - Large-Scale Storage Technologies in the Context of future German Transmission Grid Congestions T2 - 7th International Renewable Energy Storage Conference, 12.11.-14.11.2012, Berlin Y1 - 2012 CY - Berlin ER - TY - CHAP A1 - Echternacht, David A1 - Linnemann, Christian A1 - Moser, Albert T1 - Optimized positioning of measurements in distribution grids T2 - 2012 3rd IEEE PES Innovative Smart Grid Technologies Europe (ISGT Europe), 14.10.2012 - 17.10.2012, Berlin Y1 - 2012 UR - http://ieeexplore.ieee.org/document/6465628/ SN - 978-1-4673-2597-4 U6 - https://doi.org/10.1109/ISGTEurope.2012.6465628 SP - 1 EP - 7 PB - IEEE ER - TY - BOOK A1 - Echternacht, David A1 - Moser, Albert T1 - Cost optimal meter placement in low and medium voltagte grids considering stochastic dependencies T3 - IEEE PES ISGT Europe 2013, 06.10.2013 - 09.10.2013, Lyngby Y1 - 2013 UR - http://ieeexplore.ieee.org/document/6695335/ SN - 978-1-4799-2984-9 U6 - https://doi.org/10.1109/ISGTEurope.2013.6695335 SP - 1 EP - 5 PB - IEEE ER - TY - CHAP A1 - Echternacht, David A1 - Neusel-Lange, N. A1 - Schermuly, Rainer A1 - Meyer, F. T1 - Target Network Planning and Asset Condition Assessment as Basis for an integrated Asset Management Approach T2 - ETG Congress 2017, Bonn, 28.11.-29.11.2017 Y1 - 2017 CY - Bonn ER - TY - CHAP A1 - Echternacht, David A1 - Schermuly, Rainer ED - Cichowski, Rolf Rüdiger T1 - Simulation der Auswirkungen privater Ladeinfrastruktur auf Niederspannungsnetze T2 - Anlagentechnik 2020 Y1 - 2019 SN - 978-3-8007-4838-9 SP - 149 EP - 158 PB - VDE Verlag CY - Berlin ET - Neuerscheinung ER - TY - CHAP A1 - Echternacht, David A1 - Schultze, Nico ED - Cichowski, Rolf Rüdiger T1 - Integriertes Asset Management als Basis einer Energiewendegerechten Instandhaltungs- und Investitionsstrategie T2 - Anlagentechnik 2018: Anlagentechnik für elektrische Verteilungsnetze Y1 - 2018 SN - 9783802211669 VL - Anlagentechnik für elektrische Verteilungsnetze SP - 167 EP - 173 PB - EW Medien und Kongresse CY - Frankfurt am Main ER - TY - CHAP A1 - Echternacht, David A1 - Stagge, Hanno A1 - Priebe, Jens A1 - Wiernes, Pablo Ezequiel A1 - Jagielski, Kai A1 - Petri, Anne-Kathrin A1 - Drießen, Sarah A1 - Trevisan, Bianka A1 - Digmayer, Claas A1 - Oberst, Christian A. A1 - Keysselitz, Bärbel A1 - Kremer, Martin A1 - Sieber, Sandra A1 - Krapp, Stefan A1 - Jakobs, Eva-Maria A1 - Frenz, Martin A1 - Lohrberg, Frank A1 - Wachten, Kunibert A1 - Moser, Albert T1 - Modelling, Planning, Design and Evaluation of DC-Distribution Grids T2 - International ETG Congress 2015 : die Energiewende ; blueprints for the new energy age ; proceedings ; November 17 - 18, 2015, World Conference Center, Bonn Y1 - 2015 UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7388494 SP - 289 EP - 295 PB - VDE-Verl. CY - Bonn ER - TY - CHAP A1 - Gitis, Alexander A1 - Sauer, Dirk-Uwe A1 - Moser, Albert A1 - Echternacht, David A1 - Kleimaier, Martin A1 - Becker, Andreas A1 - Aundrup, Thomas A1 - Berthold, Andreas A1 - Pokojski, Martin A1 - Leuthold, Matthias A1 - Rotering, Niklas T1 - Dezentrale Energiespeicher: Einsatzmöglichkeiten, Bedarf und Wirtschaftlichkeit T2 - VDE-Kongress 2014 - Smart Cities - Intelligente Lösungen für das Leben in der Zukunft 20.10.2014 - 21.10.2014 in Frankfurt am Main Y1 - 2014 SP - 1 EP - 6 PB - VDE CY - Frankfurt am Main ER - TY - CHAP A1 - Kippelt, Stefan A1 - Rehtanz, Christian A1 - Gitis, Alexander Mihailovic A1 - Leuthold, Matthias A1 - Sauer, Dirk Uwe A1 - Echternacht, David A1 - Rotering, Niklas A1 - Moser, Albert A1 - Kleimaier, Martin A1 - Loges, Hauke A1 - Becker, Andreas A1 - Aundrup, Thomas A1 - Berthold, Andreas A1 - Pokojski, Martin T1 - Dezentrale Energiespeicher: Studie zu Stromspeichern in der Nieder- und Mittelspannungsebene T2 - Von Smart Grids zu Smart Markets 2015 - Beiträge der ETG-Fachtagung 25.03.2015 - 26.03.2015 in Kassel, Deutschland Y1 - 2015 PB - ETG CY - Kassel ER - TY - CHAP A1 - Linnemann, Christian A1 - Echternacht, David A1 - Breuer, Christopher A1 - Heuberger, Daniel A1 - Moser, Albert T1 - Ermittlung vorteilhafter HGÜ-Anschlussknoten T2 - Smart Grid: Intelligente Energieversorgung der Zukunft ; Kongressbeitäge ; 5. - 6. November 2012, Internationales Congresscenter Stuttgart (ICS) Y1 - 2012 SN - 978-3-8007-3446-7 PB - VDE-Verl. CY - Berlin ER - TY - CHAP A1 - Linnemann, Christian A1 - Echternacht, David A1 - Breuer, Christopher A1 - Moser, Albert T1 - Modeling optimal redispatch for the European Transmission grid T2 - 2011 IEEE Trondheim PowerTech,19.06.2011 - 23.06.2011, Trondheim Y1 - 2011 UR - http://ieeexplore.ieee.org/document/6019442/ SN - 978-1-4244-8418-8 U6 - https://doi.org/10.1109/PTC.2011.6019442 SP - 1 EP - 8 PB - IEEE ER - TY - CHAP A1 - Neme, Christopher A1 - Seefeldt, Friedrich A1 - Gottstein, Meg A1 - Echternacht, David A1 - Moser, Albert A1 - Weston, Frederick T1 - The Positive Effects of Energy Efficiency on the German Electricity Sector: Peer-reviewed paper presented at IEPPEC 2014 International Energy Policies & Programmes Evaluation Conference T2 - 15. International Energy Policies & Programmes Evaluation Conference (IEPEC), Berlin, Deutschland, 09.09-11.09.2014 Y1 - 2014 UR - https://www.agora-energiewende.de/en/publications/the-positive-effects-of-energy-efficiency-on-the-german-electricity-sector/ SP - 1 EP - 16 CY - Berlin ER - TY - JOUR A1 - Braun, Alexander T1 - Automotive mass production of camera systems: Linking image quality to AI performance JF - tm - Technisches Messen N2 - Artificial intelligence methods based on machine learning or artificial neural networks have become indispensable in camera-based driver assistance systems, and also represent an essential building block for future autonomous driving. However, the great successes of these evaluation methods in environment perception and also driving planning are accompanied by equally great challenges in the validation and verification of these systems. One of the essential aspects for this is the required guaranteed safety of the functions under mass production conditions of the vehicles. This article explains this point of view using a detailed example from the field of camera-based driver assistance systems: the determination of inspection limits at the end of the production line. The camera is one of the most important sensor modalities for vehicle environment sensing and as such, the quality of the camera systems plays a key role in the safety argumentation of the overall system. Several illustrative application examples (role of simulations, calibration, influence of the windshield) will be presented. The basic ideas presented can be well transferred to the other sensor modalities (lidar, radar, ToF, etc.). The investigations/evidence show that doubts are allowed whether or how fast autonomous driving on level L4/5 will take hold as robotaxis or – even more challenging – in private ownership on a larger scale. KW - Electrical and Electronic Engineering KW - Instrumentation Y1 - 2022 U6 - https://doi.org/10.1515/teme-2022-0029 SN - 2196-7113 PB - Walter de Gruyter ER - TY - CHAP A1 - Balzer, Chr. A1 - Hannemann, Th. A1 - Wunderlich, Chr. A1 - Braun, Alexander A1 - Ettler, M. A1 - Paape, Chr. A1 - Neuhauser, W. T1 - Efficient photoionisation, preparation and coherent manipulation of trapped /sup 171/Yb/sup +/-ions T2 - EQEC '05. European Quantum Electronics Conference, 12-17 June 2005, Munich Y1 - 2005 UR - http://ieeexplore.ieee.org/document/1567474/ SN - 0-7803-8973-5 U6 - https://doi.org/10.1109/EQEC.2005.1567474 SP - 308 PB - IEEE ER - TY - THES A1 - Braun, Alexander T1 - Addressing Single Yb+ Ions: A new scheme for quantum computing in linear ion traps Y1 - 2007 SN - 978-3-86727-276-6 PB - Cuvillier Verlag CY - Göttingen ER - TY - JOUR A1 - Wittpahl, Christian A1 - Zakour, Hatem Ben A1 - Lehmann, Matthias A1 - Braun, Alexander T1 - Realistic Image Degradation with Measured PSF JF - Electronic Imaging, Autonomous Vehicles and Machines 2018 KW - SiL/HiL Y1 - 2018 U6 - https://doi.org/10.2352/ISSN.2470-1173.2018.17.AVM-149 SN - 2470-1173 IS - 17 PB - Society for Imaging Science and Technology ER - TY - JOUR A1 - Tseng, Ethan A1 - Mosleh, Ali A1 - Mannan, Fahim A1 - St-Arnaud, Karl A1 - Sharma, Avinash A1 - Peng, Yifan A1 - Braun, Alexander A1 - Nowrouzezahrai, Derek A1 - Lalonde, Jean-François A1 - Heide, Felix T1 - Differentiable Compound Optics and Processing Pipeline Optimization for End-to-end Camera Design JF - ACM Transactions on Graphics N2 - Most modern commodity imaging systems we use directly for photography‐-or indirectly rely on for downstream applications‐-employ optical systems of multiple lenses that must balance deviations from perfect optics, manufacturing constraints, tolerances, cost, and footprint. Although optical designs often have complex interactions with downstream image processing or analysis tasks, today’s compound optics are designed in isolation from these interactions. Existing optical design tools aim to minimize optical aberrations, such as deviations from Gauss’ linear model of optics, instead of application-specific losses, precluding joint optimization with hardware image signal processing (ISP) and highly parameterized neural network processing. In this article, we propose an optimization method for compound optics that lifts these limitations. We optimize entire lens systems jointly with hardware and software image processing pipelines, downstream neural network processing, and application-specific end-to-end losses. To this end, we propose a learned, differentiable forward model for compound optics and an alternating proximal optimization method that handles function compositions with highly varying parameter dimensions for optics, hardware ISP, and neural nets. Our method integrates seamlessly atop existing optical design tools, such as Zemax. We can thus assess our method across many camera system designs and end-to-end applications. We validate our approach in an automotive camera optics setting‐-together with hardware ISP post processing and detection‐-outperforming classical optics designs for automotive object detection and traffic light state detection. For human viewing tasks, we optimize optics and processing pipelines for dynamic outdoor scenarios and dynamic low-light imaging. We outperform existing compartmentalized design or fine-tuning methods qualitatively and quantitatively, across all domain-specific applications tested. Y1 - 2021 U6 - https://doi.org/10.1145/3446791 SN - 1557-7368 VL - 40 IS - 2 SP - 1 EP - 19 PB - Association for Computing Machinery CY - New York, NY, USA ER - TY - CHAP A1 - Mueller, Patrick A1 - Lehmann, Matthias A1 - Braun, Alexander T1 - Simulating tests to test simulation T2 - IS&T International Symposium on Electronic Imaging 2020: Autonomous Vehicles and Machines, 26 January 2020 — 30 January 2020, Burlingame, CA, USA Y1 - 2020 U6 - https://doi.org/10.2352/ISSN.2470-1173.2020.16.AVM-149 VL - 2020 IS - 16 PB - Society for Imaging Science and Technology ER - TY - JOUR A1 - Krebs, Christian A1 - Müller, Patrick A1 - Braun, Alexander T1 - Impact of Windshield Optical Aberrations on Visual Range Camera Based Classification Tasks Performed by CNNs JF - London Imaging Meeting Y1 - 2021 SN - 0-89208-346-6 U6 - https://doi.org/10.2352/issn.2694-118X.2021.LIM-83 SN - 2694-118X VL - 2021 IS - 1 SP - 83 EP - 87 PB - Ingenta connect ER - TY - CHAP A1 - Johanning, M. A1 - Braun, Alexander A1 - Elman, V. A1 - Wunderlich, Chr. A1 - Neuhauser, W. T1 - Individual Addressing with Trapped Yb+ Ions T2 - 2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, 17.06.2007 - 22.06.2007, Munich, Germany Y1 - 2007 UR - http://ieeexplore.ieee.org/document/4386787/ SN - 978-1-4244-0930-3 U6 - https://doi.org/10.1109/CLEOE-IQEC.2007.4386787 PB - IEEE CY - München ER - TY - JOUR A1 - Johanning, M. A1 - Braun, Alexander A1 - Timoney, N. A1 - Elman, V. A1 - Neuhauser, W. A1 - Wunderlich, Chr T1 - Individual addressing of trapped ions and coupling of motional and spin states using RF radiation JF - Physical review letters N2 - Individual electrodynamically trapped and laser cooled ions are addressed in frequency space using radio-frequency radiation in the presence of a static magnetic field gradient. In addition, an interaction between motional and spin states induced by an rf field is demonstrated employing rf optical double resonance spectroscopy. These are two essential experimental steps towards realizing a novel concept for implementing quantum simulations and quantum computing with trapped ions. Y1 - 2009 UR - http://www.ncbi.nlm.nih.gov/pubmed/19257664 U6 - https://doi.org/10.1103/PhysRevLett.102.073004 SN - 1079-7114 VL - 102 IS - 7 PB - American Physical Society ER - TY - JOUR A1 - Johanning, M. A1 - Braun, Alexander A1 - Eiteneuer, D. A1 - Paape, C. A1 - Balzer, C. A1 - Neuhauser, W. A1 - Wunderlich, C. T1 - Resonance-enhanced isotope-selective photoionization of YbI for ion trap loading JF - Applied Physics B Y1 - 2011 UR - https://arxiv.org/pdf/0712.0969.pdf U6 - https://doi.org/10.1007/s00340-011-4502-7 SN - 1432-0649 VL - 103 IS - 2 SP - 327 EP - 338 PB - Springer Nature ER - TY - JOUR A1 - Braun, Alexander A1 - Kornmesser, Christoph A1 - Beushausen, Volker T1 - Simultaneous spatial and spectral imaging of lasing droplets JF - Journal of the Optical Society of America N2 - We present an experimental technique that allows the simultaneous spatial imaging and spectral analysis of falling droplets that exhibit lasing. Single droplet investigations serve as, among other purposes, a preliminary study for spray and combustion researchers. The described setup provides a valuable tool for the evaluation of microdroplet investigations with laser-spectroscopic techniques that rely on laser-induced fluorescence (LIF) or similar spectroscopical phenomena. The emphasis is that both spatial and spectral information are obtained from single-shot images of a falling droplet. Furthermore, combining spatial imaging and a spatially resolving optical multichannel analyzer makes a pointwise rastering of the droplets spectrum possible. This allows for the (almost) unambiguous determination of sources of influence on the spectrum of these droplets-such as geometrical distortion and lasing, nondissolved tracer lumps, and similar phenomena. Although the focus is on the experimental technique itself, we supplement detailed studies of lasing in falling microdroplets. These results were obtained with the aim of developing a system for measuring temperature distributions in droplets and sprays. In the light of these results the practice of calibrating a droplets spectrum by use of a bulk liquid sample needs to be critically reviewed. Y1 - 2005 U6 - https://doi.org/10.1364/josaa.22.001772 SN - 0030-3941 VL - 22 IS - 9 SP - 1772 EP - 1779 PB - Optical Society of America ER - TY - GEN A1 - Braun, Alexander T1 - Laserspektroskopische Messverfahren zur Temperaturbestimmung in Sprays Y1 - 2001 PB - Georg-August-Universität Göttingen CY - Göttingen ER - TY - JOUR A1 - Balzer, Chr. A1 - Braun, Alexander A1 - Hannemann, T. A1 - Paape, Chr. A1 - Ettler, M. A1 - Neuhauser, W. A1 - Wunderlich, Chr. T1 - Electrodynamically trapped Yb+ ions for quantum information processing JF - Physical Review A Y1 - 2006 U6 - https://doi.org/10.1103/PhysRevA.73.041407 SN - 2469-9934 VL - 73 IS - 4 PB - American Physical Society ER - TY - JOUR A1 - Heizmann, Michael A1 - Braun, Alexander A1 - Glitzner, Markus A1 - Günther, Matthias A1 - Hasna, Günther A1 - Klüver, Christina A1 - Krooß, Jakob A1 - Marquardt, Erik A1 - Overdick, Michael A1 - Ulrich, Markus T1 - Implementing machine learning: chances and challenges JF - at - Automatisierungstechnik Y1 - 2022 U6 - https://doi.org/10.1515/auto-2021-0149 SN - 2196-677X VL - 70 IS - 1 SP - 90 EP - 101 PB - De Gruyter CY - Berlin ER - TY - CHAP A1 - Christmann, Simon A1 - Busboom, Imke A1 - Feige, Volker K.S. A1 - Haehnel, Hartmut T1 - Towards Automated Quality Inspection Using a Semi-Mobile Robotized Terahertz System T2 - 2020 Third International Workshop on Mobile Terahertz Systems (IWMTS) KW - angle compensation KW - automatic alignment KW - Projekt Smart Production KW - robot KW - terahertz time-domain spectroscopy KW - thickness measurements Y1 - 2020 SN - 978-1-7281-5598-2 U6 - https://doi.org/10.1109/IWMTS49292.2020.9166259 SP - 1 EP - 5 PB - IEEE CY - Essen ER - TY - JOUR A1 - Schuller, Bjorn A1 - Vlasenko, Bogdan A1 - Eyben, Florian A1 - Wollmer, Martin A1 - Stuhlsatz, André A1 - Wendemuth, Andreas A1 - Rigoll, Gerhard T1 - Cross-Corpus Acoustic Emotion Recognition: Variances and Strategies JF - IEEE Transactions on Affective Computing Y1 - 2010 U6 - https://doi.org/10.1109/t-affc.2010.8 VL - 1 IS - 2 SP - 119 EP - 131 PB - IEEE ER - TY - JOUR A1 - Lyalina, Yuliya A1 - Langmann, Reinhard A1 - Krisilov, V. T1 - The Interaction Model in iLearning Environments and its Use in the Smart Lab Concept JF - International Journal of Online Engineering Y1 - 2011 U6 - https://doi.org/10.3991/ijoe.v7i4.1793 VL - 7 IS - 4 PB - iJOE ER - TY - JOUR A1 - Queval, Loic A1 - Gottkehaskamp, Raimund T1 - Analytical Field Calculation of Modulated Double Helical Coils JF - IEEE Transactions on Applied Superconductivity Y1 - 2015 U6 - https://doi.org/10.1109/tasc.2015.2477377 VL - 25 IS - 6 SP - 1 EP - 7 PB - IEEE ER - TY - JOUR A1 - Franz, Jürgen T1 - Benefits of Communication Methods in Environmental Protection JF - IETE Technical Review Y1 - 1996 U6 - https://doi.org/10.1080/02564602.1996.11416600 VL - 13 IS - 3 SP - 153 EP - 162 PB - Taylor & Francis ER - TY - JOUR A1 - Jain, V. K. A1 - Franz, J. H. T1 - Some Design Issues in Infrared Wireless Networks JF - IETE Technical Review Y1 - 2004 U6 - https://doi.org/10.1080/02564602.2004.11417161 VL - 21 IS - 5 SP - 335 EP - 343 PB - Taylor & Francis ER - TY - JOUR A1 - Heinicke, Christian A1 - Baekler, Peter A1 - Hehl, Friedrich W. T1 - Einstein-aether theory, violation of Lorentz invariance, and metric-affine gravity JF - Physical Review D Y1 - 2005 U6 - https://doi.org/10.1103/physrevd.72.025012 VL - 72 IS - 2 PB - APS ER - TY - JOUR A1 - Baekler, Peter A1 - Hehl, Friedrich W. T1 - ROTATING BLACK HOLES IN METRIC-AFFINE GRAVITY JF - International Journal of Modern Physics D Y1 - 2006 U6 - https://doi.org/10.1142/s0218271806008589 VL - 15 IS - 5 SP - 635 EP - 668 PB - World Scientific ER - TY - JOUR A1 - Langmann, Reinhard T1 - Distributed Web-Based Control System JF - International Journal of Online Engineering (iJOE) Y1 - 2010 U6 - https://doi.org/10.3991/ijoe.v6i3.1345 VL - 6 IS - 3 PB - iJOE ER - TY - JOUR A1 - Baekler, Peter A1 - Hehl, Friedrich W. A1 - Nester, James M. T1 - Poincaré gauge theory of gravity: Friedman cosmology with even and odd parity modes: Analytic part JF - Physical Review D Y1 - 2011 U6 - https://doi.org/10.1103/physrevd.83.024001 VL - 83 IS - 2 PB - APS ER - TY - JOUR A1 - Baekler, Peter A1 - Hehl, Friedrich W. T1 - Beyond Einstein–Cartan gravity: quadratic torsion and curvature invariants with even and odd parity including all boundary terms JF - Classical and Quantum Gravity Y1 - 2011 U6 - https://doi.org/10.1088/0264-9381/28/21/215017 VL - 28 IS - 21 PB - IOP ER - TY - JOUR A1 - Langmann, Reinhard A1 - Stiller, Michael T1 - Industrial Cloud – Status und Ausblick JF - HMD Praxis der Wirtschaftsinformatik Y1 - 2015 U6 - https://doi.org/10.1365/s40702-015-0162-0 VL - 52 IS - 5 SP - 647 EP - 664 PB - Springer Nature ER - TY - JOUR A1 - Richter, Jessica A1 - Steenmann, Anna A1 - Schellscheidt, Benjamin A1 - Licht, Thomas T1 - On-Chip Diffusion Bonding creates Stable Interconnections Usable at Temperatures over 300°C JF - International Symposium on Microelectronics Y1 - 2019 U6 - https://doi.org/10.4071/2380-4505-2019.1.000530 VL - 2019 IS - 1 SP - 000530 EP - 000534 PB - IMAPS ER - TY - JOUR A1 - Kagermann, Dominik A1 - Lang, Kati A1 - Roscher, Angélique T1 - Mehr Lernerfolg durch die Digitalisierung der Lehre JF - Sales Excellence Y1 - 2020 U6 - https://doi.org/10.1007/s35141-020-0392-9 VL - 29 IS - 11 SP - 20 EP - 23 PB - Springer ER - TY - JOUR A1 - Heizmann, Michael A1 - Braun, Alexander A1 - Hüttel, Markus A1 - Klüver, Christina A1 - Marquardt, Erik A1 - Overdick, Michael A1 - Ulrich, Markus T1 - Artificial intelligence with neural networks in optical measurement and inspection systems JF - at - Automatisierungstechnik Y1 - 2020 U6 - https://doi.org/10.1515/auto-2020-0006 VL - 68 IS - 6 SP - 477 EP - 487 PB - De Gruyter ER - TY - JOUR A1 - Di Gioia, Antonio A1 - Brown, Ian P. A1 - Nie, Yue A1 - Knippel, Ryan A1 - Ludois, Daniel C. A1 - Dai, Jiejian A1 - Hagen, Skyler A1 - Alteheld, Christian T1 - Design and Demonstration of a Wound Field Synchronous Machine for Electric Vehicle Traction With Brushless Capacitive Field Excitation JF - IEEE Transactions on Industry Applications N2 - This paper describes the modeling, optimization, mechanical design, and experimental characterization of a high power density wound field synchronous machine (WFSM) for electric vehicle traction applications. The WFSM is designed for brushless rotor field excitation using an axial flux hydrodynamic capacitive power coupler (CPC). The flexible design environment, which was used for large-scale multiobjective optimization of the WFSM, is described. A prototype WFSM, spray cooled with automatic transmission fluid, with an 80-kW output at a base speed of 4000 r/min has been tested. The prototyped WFSM achieves volumetric torque and power densities of 17.22 N·m/L and 7.19 kW/L referred to the envelope cylindrical volume of the active materials plus spray cooling rings. The specific torque and power densities are 4.69 N·m/kg and 1.95 kW/kg referred to the mass of the active materials and the shaft. The prototyped CPC provided up to 1-kW excitation power with a mass 600 g and volume of 0.271 L. Y1 - 2018 U6 - https://doi.org/10.1109/tia.2017.2784799 VL - 54 IS - 2 SP - 1390 EP - 1403 PB - IEEE ER - TY - CHAP A1 - Müller, Patrick A1 - Lehmann, Matthias A1 - Braun, Alexander ED - Kress, Bernard C. ED - Schelkens, Peter T1 - Optical quality metrics for image restoration T2 - Digital Optical Technologies 2019 N2 - Image restoration is a process used to remove blur (from different sources like object motion or aberrations) from images by either non-blind or blind-deconvolution. The metrics commonly used to quantify the restoration process are peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM). Often only a small sample of test images are used (like Lena or the camera guy). In optical design research PSNR and SSIM are not normally used, here image quality metrics based on linear system theory (e.g. modulation transfer function, MTF) are used to quantify optical errors like spherical or chromatic aberration. In this article we investigate how different image restoration algorithms can be quantified by applying image quality metrics. We start with synthetic image data that is used in camera test stands (e.g. Siemens star etc.), apply two different spatially variant degradation algorithms, and restore the original image by a direct method (Wiener filtering within sub-images), and by an iterative method (alternating direction method of multipliers, ADMM). Afterwards we compare the quality metrics (like MTF curves) for the original, the degraded and the restored image. As a first result we show that restoration algorithms sometimes fail in dealing with non-natural scenes, e.g. slanted-edge targets. Further, these first results indicate a correlation between degradation and restoration, i.e. the restoration algorithms are not capable of removing the optically relevant errors introduced by the degradation, a fact neither visible nor available from the PSNR values. We discuss the relevance in the context of the automotive industry, where image restoration may yield distinct advantages for camera-based applications, but testing methods rely on the used image quality metrics. Y1 - 2019 U6 - https://doi.org/10.1117/12.2528100 VL - Proceedings, Vol. 11062 CY - Munich ER - TY - JOUR A1 - Lehmann, Matthias A1 - Wittpahl, Christian A1 - Zakour, Hatem Ben A1 - Braun, Alexander T1 - Resolution and accuracy of nonlinear regression of point spread function with artificial neural networks JF - Optical Engineering N2 - We had already demonstrated a numerical model for the point spread function (PSF) of an optical system that can efficiently model both the experimental measurements and the lens design simulations of the PSF. The novelty lies in the portability and the parameterization of this model, which allow for completely new ways to validate optical systems, which is especially interesting not only for mass production optics such as in the automotive industry but also for ophthalmology. The numerical basis for this model is a nonlinear regression of the PSF with an artificial neural network (ANN). After briefly describing both the principle and the applications of the model, we then discuss two optically important aspects: the spatial resolution and the accuracy of the model. Using mean squared error (MSE) as a metric, we vary the topology of the neural network, both in the number of neurons and in the number of hidden layers. Measurement and simulation of a PSF can have a much higher spatial resolution than the typical pixel size used in current camera sensors. We discuss the influence this has on the topology of the ANN. The relative accuracy of the averaged pixel MSE is below 10  −  4, thus giving confidence that the regression does indeed model the measurement data with good accuracy. This article is only the starting point, and we propose several research avenues for future work. Y1 - 2019 U6 - https://doi.org/10.1117/1.oe.58.4.045101 SN - 0091-3286 VL - 58 IS - 4 SP - 045101 PB - SPIE ER - TY - JOUR A1 - Lehmann, Matthias A1 - Wittpahl, Christian A1 - Zakour, Hatem Ben A1 - Braun, Alexander T1 - Modeling realistic optical aberrations to reuse existing drive scene recordings for autonomous driving validation JF - Journal of Electronic Imaging N2 - Training autonomous vehicles requires lots of driving sequences in all situations. Collecting and labeling these drive scenes is a very time-consuming and expensive process. Currently, it is not possible to reuse these drive scenes with different optical properties, because there exists no numerically efficient model for the transfer function of the optical system. We present a numerical model for the point spread function (PSF) of an optical system that can efficiently model both experimental measurements and lens design simulations of the PSF. The numerical basis for this model is a nonlinear regression of the PSF with an artificial neural network. The novelty lies in the portability and the parameterization of this model. We present a lens measurement series, yielding a numerical function for the PSF that depends only on the parameters defocus, field, and azimuth. By convolving existing images and videos with this PSF, we generate images as if seen through the measured lens. The methodology applies to any optical scenario, but we focus on the context of autonomous driving, where the quality of the detection algorithms depends directly on the optical quality of the used camera system. With this model, it is possible to reuse existing recordings, with the potential to avoid millions of test drive miles. The parameterization of the optical model allows for a method to validate the functional and safety limits of camera-based advanced driver assistance systems based on the real, measured lens actually used in the product. Y1 - 2019 U6 - https://doi.org/10.1117/1.JEI.28.1.013005 SN - 1560-229X VL - 28 IS - 1 SP - 013005 PB - SPIE ER - TY - CHAP A1 - Lehmann, Matthias A1 - Wittpahl, Christian A1 - Zakour, Hatem Ben A1 - Braun, Alexander ED - Haverkamp, Nils ED - Youngworth, Richard N. T1 - Resolution and accuracy of non-linear regression of PSF with artificial neural networks T2 - SPIE Optical Systems Design: Optical Instrument Science, Technology, and Applications, 2018, Frankfurt, Germany N2 - In a previous work we have demonstrated a novel numerical model for the point spread function (PSF) of an optical system that can efficiently model both experimental measurements and lens design simulations of the PSF. The novelty lies in the portability and the parameterization of this model, which allows for completely new ways to validate optical systems, which is especially interesting for mass production optics like in the automotive industry, but also for ophtalmology. The numerical basis for this model is a non-linear regression of the PSF with an artificial neural network (ANN). In this work we examine two important aspects of this model: the spatial resolution and the accuracy of the model. Measurement and simulation of a PSF can have a much higher resolution then the typical pixel size used in current camera sensors, especially those for the automotive industry. We discuss the influence this has on on the topology of the ANN and the final application where the modeled PSF is actually used. Another important influence on the accuracy of the trained ANN is the error metric which is used during training. The PSF is a distinctly non-linear function, which varies strongly over field and defocus, but nonetheless exhibits strong symmetries and spatial relations. Therefore we examine different distance and similarity measures and discuss its influence on the modeling performance of the ANN. Y1 - 2018 U6 - https://doi.org/10.1117/12.2313144 N1 - Preprint bei ArXiv verfügbar. VL - Proc. SPIE, Vol. 10695 IS - 106950C SP - 52 EP - 63 PB - International Society for Optics and Photonics CY - Frankfurt ER -