TY - JOUR A1 - Sallum, Loriz Francisco A1 - Alves, Caroline A1 - Thielemann, Christiane A1 - Rodrigues, Francisco A. T1 - Revealing patterns in major depressive disorder with machine learning and networks JF - medrxiv N2 - Major depressive disorder (MDD) is a multifaceted condition that affects millions of people worldwide and is a leading cause of disability. There is an urgent need for an automated and objective method to detect MDD due to the limitations of traditional diagnostic approaches. In this paper, we propose a methodology based on machine and deep learning to classify patients with MDD and identify altered functional connectivity patterns from EEG data. We compare several connectivity metrics and machine learning algorithms. Complex network measures are used to identify structural brain abnormalities in MDD. Using Spearman correlation for network construction and the SVM classifier, we verify that it is possible to identify MDD patients with high accuracy, exceeding literature results. The SHAP (SHAPley Additive Explanations) summary plot highlights the importance of C4-F8 connections and also reveals dysfunction in certain brain areas and hyperconnectivity in others. Despite the lower performance of the complex network measures for the classification problem, assortativity was found to be a promising biomarker. Our findings suggest that understanding and diagnosing MDD may be aided by the use of machine learning methods and complex networks. KW - Depression KW - Elektroencephalographie KW - Maschinelles Lernen Y1 - 2024 U6 - https://doi.org/doi.org/10.1101/2024.06.07.24308619 VL - 2024 IS - 1 SP - 1 EP - 17 ER - TY - JOUR A1 - Szewczyk, Nathaniel J. A1 - Monici, Monica A1 - Thielemann, Christiane T1 - How to obtain an integrated picture of the molecular networks involved in adaptation to microgravity in different biological systems? JF - npj Microgravity N2 - Periodically, the European Space Agency (ESA) updates scientific roadmaps in consultation with the scientific community. The ESA SciSpacE Science Community White Paper (SSCWP) 9, “Biology in Space and Analogue Environments”, focusses in 5 main topic areas, aiming to address key community-identified knowledge gaps in Space Biology. Here we present one of the identified topic areas, which is also an unanswered question of life science research in Space: “How to Obtain an Integrated Picture of the Molecular Networks Involved in Adaptation to Microgravity in Different Biological Systems?” The manuscript reports the main gaps of knowledge which have been identified by the community in the above topic area as well as the approach the community indicates to address the gaps not yet bridged. Moreover, the relevance that these research activities might have for the space exploration programs and also for application in industrial and technological fields on Earth is briefly discussed. KW - Weltraumforschung KW - Biowissenschaften Y1 - 2024 U6 - https://doi.org/DOI: 10.1038/s41526-024-00395-3 VL - 2024 IS - 10 SP - 1 EP - 5 ER - TY - BOOK A1 - Lauer, Thomas T1 - Change Management: Grundlagen und Erfolgsfaktoren KW - Change Management KW - Erfolgsfaktor KW - Agilität Management Y1 - 2019 SN - 978-3-662-59101-7 U6 - https://doi.org/10.1007/978-3-662-59102-4 PB - Springer Gabler CY - Berlin ET - 3., vollständig überarbeitete und erweiterte Auflage ER - TY - RPRT A1 - Jost, Thomas A1 - Mink, Reimund T1 - Central bank losses and commercial bank profits - unexpected and unfair? T2 - IMFS Working Paper Series No. 199 N2 - The Eurosystem and the Deutsche Bundesbank will incur substantial losses in 2023 that are likely to persist for several years. Due to the massive purchases of securities in the last 10 years, especially of government bonds, the banks' excess reserves have risen sharply. The resulting high interest payments to the banks since the turnaround in monetary poli-cy, with little income for the large-scale securities holdings, led to massive criticism. The banks were said to be making "unfair" profits as a result, while the fiscal authorities had to forego the previously customary transfers of central bank profits. Populist demands to limit bank profits by, for example, drastically increasing the minimum reserve ratios in the Eurosystem to reduce excess reserves are creating new severe problems and are neither justified nor helpful. Ultimately, the EU member states have benefited for a very long time from historically low interest rates because of the Eurosystem's extraordinary loose monetary policy and must now bear the flip side consequences of the massive expansion of central bank balance sheets during the necessary period of monetary policy normalisa-tion. KW - Notenbank KW - Geldpolitik KW - Geschäftsbank KW - Deutsche Bundesbank KW - Central bank losses, monetary policy, ecb, minimum reserve Y1 - 2024 UR - https://www.econbiz.de/Record/central-bank-losses-and-commercial-bank-profits-unexpected-and-unfair-jost-thomas/10014476309 ER - TY - GEN A1 - Jost, Thomas A1 - Mink, Reimund T1 - How to deal with the negative effects of inflated central bank balance sheets? N2 - Due to the massive purchases of securities in the last 15 years central banks incur substantial losses likely to persist for several years. On the other hand, the banking sector gains large profits from interest payments on their excess reserves holdings. Central banks and fiscal authorities must now bear the flip side consequences of their bond purchase programs. Populist demands to limit bank profits by drastically increasing minimum reserve ratios in the Eurosystem are creating new severe problems. Instead, a consistent and faster normalisation of central bank balance sheets would be desirable. Central banks should also no longer be central players in government bond markets to restore the lost boundaries between fiscal and monetary policy. KW - Europäische Zentralbank KW - Geldpolitik KW - Notenbank KW - ecb, minimum reserve, monetary policy Y1 - 2024 UR - https://www.suerf.org/wp-content/uploads/2024/04/SUERF-Policy-Brief-860_Jost-Mink.pdf SP - 1 EP - 4 ER - TY - BOOK A1 - Hofmann, Georg Rainer A1 - Scheidler, Percy T1 - Chief Qualification Officer (CQO) und Weiterbildungsmentoren N2 - Alte Weisheiten wie „Schuster bleib bei deinem Leisten!“ oder auch „Was das Hänschen nicht lernt, das lernt der Hans nimmermehr“ haben in der heutigen, sich wandelnden Arbeitswelt ihren Sinn verloren. Das bedeutet, dass sich die komplette Belegschaft lebenslang weiterbilden muss, idealerweise mit Unterstützung des Arbeitgebers. In der Veröffentlichung "Chief Qualification Officers (CQOs) und Weiterbildungsmentoren - Thesen und Argumente" wird unter anderem das paradoxe Verhältnis von Arbeitslosigkeit und Fachkräftemangel erläutert, das Marktversagen im Weiterbildungsmarkt beschrieben und die Forderung nach einem Weiterbildungsbeauftragten (CQO) begründet. KW - Weiterbildungsmentoren KW - Weiterbildung KW - Erwachsenenbildung KW - Lebenslanges Lernen Y1 - 2024 UR - https://www.mainproject.eu/shop SN - 978-3-9826305-0-2 ER - TY - CHAP A1 - Smeets, Mario A1 - Rötzel, Peter T1 - The Moderating Role of Non-Monetary Gamification in Reducing Algorithm Aversion in the Adoption of AI-based Decision Support Systems T2 - ECIS - European Conference on Information Systems N2 - Integrating artificial intelligence (AI) into decision-making processes is key to improving organizational performance. However, trust in AI-based decision support systems (DSSs), similar to other information systems, is important for successful integration. A disruptive phenomenon, “algorithm aversion”, can impede AI trust and, thus, acceptance. Although AI recommendations outperform human recommendations in different decision-making fields, individuals underweight recommendations from AI-based DSSs compared to human decision-makers due to a lack of AI trust. We conducted a lab experiment to investigate the role of AI recommendations in workplace-related tasks, first focusing on the mediating effect of AI trust and the negative impact of algorithm aversion on decision-making performance and the moderating effect of technical competence. Second, we analyzed the ability of gamification to reduce this phenomenon. We provide evidence regarding how to enhance decision-making performance when AI recommendations are deployed and identify countermeasures against algorithm aversion to facilitate the adoption of AI-based DSSs. KW - Decision Support Systems KW - Algorithm Aversion KW - Gamification KW - Künstliche Intelligenz KW - Gamification Y1 - 2024 VL - 2024 IS - 1 ER - TY - CHAP A1 - Sauer, Jonas A1 - Hoppe, Florian A1 - Bruhm, Hartmut T1 - Modellierung des Antriebsstrangs einer Textilmaschine zum Zweck der modellbasierten Steuerung T2 - Tagungsband AALE 2024, 20. Konferenz N2 - Zur Produktion von gewirkten Textilien werden mehrere Nadeln auf eine Legebarre gesetzt, die durch Servoantriebe positioniert werden. Aufgrund der erzwungenen Bewegung kann der Antriebsstrang bei hohen Drehzahlen zur Schwingung angeregt werden. Die richtige Wahl der Steuerkurven ist daher eine sehr wichtige und anspruchsvolle Aufgabe, die durch ein Antriebsstrangmodell unterstützt werden soll. Dafür wird am Beispiel eines Teststands ein Modell des Antriebsstranges in MATLAB/Simulink® entwickelt. Für das Antriebsstrangmodell müssen eine geeignete Modellordnung und Modellparameter gewählt werden. Die unbekannten Modellparameter werden durch eine Parameteridentifikation ermittelt. Mit einer Validierung wird ein geeignetes Anregungsspektrum für die Bestimmung der Modellordnung und die Parameteridentifikation ermittelt. KW - Textilmaschine KW - Triebstrang KW - MATLAB KW - SIMULINK KW - Modellierung KW - Grey-Box-Modell KW - Parameteridentifikation KW - MATLAB/ Simulink® KW - Inverses Modell KW - Input Shaping Y1 - 2024 U6 - https://doi.org/https://doi.org/10.33968/2024.33 VL - 2024 ER - TY - BOOK A1 - Leimeister, Katja A1 - Schumacher, Meike A1 - Wenderoth, Lucia ED - Hofmann, Georg Rainer ED - Alm, Wolfgang T1 - Krisen und Auswege : Ringvorlesung im Wintersemester 2022/2023 an der TH Aschaffenburg N2 - Krisen gab es schon immer. Aktuell hat sich jedoch ein ganzes Spektrum an Krisen entfaltet – es gibt politische und militärische Krisen, es brechen Energiemärke und Lieferketten weg, wir sehen ganze Branchen gefährdet, auch die Gesundheit macht uns Sorgen, vom Klimawandel ganz zu schweigen. In den Veranstaltungen der Ringvorlesung „Krisen und Auswege“, die im Wintersemester 2022/2023 stattfand, wurden Phänomene, Konzepte und Lösungen aus vielfältiger Perspektive erschlossen und damit die Komplexität des Gegenstands aufgezeigt. Herausforderungen für Unternehmen und Privatpersonen wurden identifiziert sowie der Einfluss auf technologische und organisatorische Entwicklungswege dargelegt. In dieser Publikation wurden die einzelnen Vorträge der Ringvorlesung von den Autorinnen zusammengefasst. KW - Nachhaltigkeit KW - Lieferketten KW - Energiemärkte KW - Mobilität KW - Gesundheitssystem KW - Krise KW - Energiemarkt KW - Klimaänderung KW - Supply Chain Management Y1 - 2023 UR - https://www.mainproject.eu/shop SN - 978-3-9823413-6-1 PB - IMI Verlag, TH Aschaffenburg CY - Aschaffenburg ER - TY - BOOK A1 - Alm, Wolfgang A1 - Hofmann, Georg Rainer A1 - Reuter, Carsten A1 - Ruppert, Erich A1 - Schumacher, Meike A1 - Leimeister, Katja A1 - Schmitt, Joachim A1 - Wenderoth, Lucia T1 - 15 Jahre Wissenstransfer am Information Management Institut (IMI) N2 - Im Sommer des Jahres 2022 hatte der Bayerische Landtag das neue Hochschulinnovationsgesetz (BayHIG) verabschiedet. Darin ist erstmals der Wissenstransfer als die dritte, neue Säule der Hochschulaufgaben enthalten. Tatsächlich hat sich das IMI bereits seit 15 Jahren dem Wissenstransfer Hochschule - Wirtschaft verschrieben und zahlreiche Projekte mit unterschiedlichem Fokus erfolgreich durchgeführt. In der vorliegenden Publikation werden die bearbeiteten Themen im Wissenstransfer, die zahlreichen verschiedenen Veranstaltungsformate sowie die Drittmittelprojekte beleuchtet. KW - Europäischer Sozialfonds, Drittmittel KW - Informationsmanagement KW - Wissenschaftstransfer Y1 - 2023 UR - https://www.mainproject.eu/shop SN - 978-3-9823413-8-5 ER - TY - BOOK A1 - Hofmann, Georg Rainer ED - Alm, Wolfgang ED - Hofmann, Georg Rainer T1 - Vertrauen als ein Verhältnis zwischen Menschen und Maschinen N2 - Der technische Fortschritt von IT-Systemen, wie zum Beispiel der sogenannten „Künstlichen Intelligenz“ (KI) oder den „Common Data Spaces“ (CDSs), bringt die Frage nach der Akzeptanz dieser Systeme mit sich. Sowohl die aktive (ökonomische) Akzeptanz in Form des Erwerbs und der Nutzung, als auch die passive (soziale) Akzeptanz in Form der Duldung der aktiven Nutzung durch Dritte, sind für den Erfolg von IT-Systemen ausschlaggebend. Eine geringe Akzeptanz der Systeme und ein mangelndes Vertrauen in dieselben wird in einen Zusammenhang gebracht: Man fragt nach der Gestaltung „zuverlässiger und vertrauenswürdiger Systeme“, da diese besonders akzeptiert werden. In diesem Beitrag werden „Vertrauen“ und dessen Zusammenhang mit „Zuverlässigkeit“ und „Verstehen“ im Kontext von IT-Systemen erörtert. KW - KI KW - Vertrauen KW - Akzeptanz KW - Künstliche Intelligenz Y1 - 2023 UR - https://www.mainproject.eu/shop SN - 978-3-9823413-7-8 PB - IMI Verlag, TH Aschaffenburg CY - Aschaffenburg ER - TY - JOUR A1 - Lutz, Christian A1 - Helm, Jonas A1 - Tschirpke, Katrin A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Drilling Sequence Optimization Using Evolutionary Algorithms to Reduce Heat Accumulation for Femtosecond Laser Drilling with Multi-Spot Beam Profiles JF - MDPI Materials N2 - We report on laser drilling borehole arrays using ultrashort pulsed lasers with a particular focus on reducing the inadvertent heat accumulation across the workpiece by optimizing the drilling sequence. For the optimization, evolutionary algorithms are used and their results are verified by thermal simulation using Comsol and experimentally evaluated using a thermal imaging camera. To enhance process efficiency in terms of boreholes drilled per second, multi-spot approaches are employed using a spatial light modulator. However, as higher temperatures occur across the workpiece when using simultaneous multi-spot drilling as compared to a single-spot process, a subtle spatial distribution and sequence of the multi-spot approach has to be selected in order to limit the resulting local heat input over the processing time. Different optimization approaches based on evolutionary algorithms aid to select those drilling sequences which allow for the combination of a high efficiency of multi-spot profiles, a low-generated process temperature and a high-component quality. In particular, using a 4 x 4 laser spot array allows for the drilling of 40,000 boreholes in less than 76 s (526 boreholes/s) with a reduced temperature increase by about 35%, as compared to a single spot process when employing an optimized drilling sequence. KW - USP laser processing KW - Laser drilling KW - Optimization of heat accumulation KW - Evolutionary Algorithms KW - Thermal simualtions KW - Laserbohren KW - Ultrakurzzeitlaser Y1 - 2023 UR - https://www.mdpi.com/1996-1944/16/17/5775 U6 - https://doi.org/10.3390/ma16175775 VL - 2023 IS - 16/5775 SP - 1 EP - 12 ER - TY - JOUR A1 - Lutz, Christian A1 - Schwarz, Simon A1 - Marx, Jan A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Multi-Bessel Beams Generated by an Axicon and a Spatial Light Modulator for Drilling Applications JF - MDPI Photonics N2 - We report on an optical setup to generate multi-Bessel beam profiles combining a refractive axicon and a spatial light modulator. Based on their particular beam profile, Bessel beams offer advantageous properties for micro drilling processes and internal volume processing, especially for transparent materials. In addition, the laser power of industrial, ultrashort pulsed lasers has increased significantly over the last few years, offering the possibility for highly efficient processes using multi-spot profiles. Our optical concept combines the dynamic possibilities of beam splitting using a spatial light modulator with the benefits of Bessel beams, which facilitates multi-Bessel beam processing. Beside the simulation and experimental evaluation of the generated multi-Bessel beams, we exemplify the applicability of the developed module for the perforation of thin metal foils by micro drilling. KW - Bessel beam KW - Axicon KW - Optical System KW - Ultrashort pulsed laser KW - Material ablation KW - Bessel-Bündel KW - Ultrakurzzeitlaser Y1 - 2023 UR - https://www.mdpi.com/2304-6732/10/4/413 U6 - https://doi.org/10.3390/photonics10040413 VL - 2023 IS - 10/413 SP - 1 EP - 9 ER - TY - JOUR A1 - Sommer, David A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Static and Dynamic Mechanical Behaviour of Hybrid-PBF-LB/M-Built and Hot Isostatic Pressed Lattice Structures JF - Mechanical Properties of Polymeric, Metallic, and Composite Materials N2 - We report on a comprehensive study of the mechanical properties of maraging steel body-centred cubic lattice structures fabricated by a hybrid additive manufacturing technology that combines laser powder bed fusion with in situ high-speed milling. As the mechanical properties of additive manufactured components are inferior to, e.g., cast components, surface modifications can improve the mechanical behaviour. Different hybrid additive manufacturing technologies have been designed using additive and subtractive processes, improving process quality. Following this, mechanical testing is performed with respect to static tensile properties and dynamic stress, hardness, and porosity, comparing specimens manufactured by laser powder bed fusion only to those manufactured by the hybrid approach. In addition, the influence of different heat-treatment techniques on the mechanical behaviour of the lattice structures is investigated, namely solution and aging treatment as well as hot isostatic pressing. Thus, the influence of the superior surface quality due to the hybrid approach is evaluated, leading to, e.g., an offset of about 14–16% for the static testing of HIP lattice structures. Furthermore, the dynamic load behaviour can be improved with a finished surface, heading to a shift of the different zones of fatigue behaviour in the testing of hybrid-built specimens. KW - Hybrid additive manufacturing KW - Lattice structures KW - Hot isostatic pressing KW - Fatigue behaviour KW - Isostatisches Heißpressen KW - Selektives Laserschmelzen Y1 - 2023 UR - https://www.mdpi.com/1996-1944/16/9/3556 U6 - https://doi.org/https://doi.org/10.3390/ma16093556 VL - 16 IS - 9 SP - 1 EP - 14 ER - TY - CHAP A1 - Marx, Jan A1 - Esen, Cemal A1 - Lutz, Christian A1 - Hellmann, Ralf A1 - Ostendorf, Andreas T1 - Holographic tuning of physical axicons N2 - Axicon generated Bessel beams are a popular tool for high aspect ratio precision laser drilling. Spot diameter and working distance are given by the geometric parameters of the axicon and the wavelength used. Thus, it is difficult to manipulate the beam shape of a Bessel beam for a given setup. Spatial light modulators (SLMs) overcome limitations in flexibility. However, due to the limited phase shift of SLMs, only Bessel beams with flat cone angles and large focal length can be generated. In this contribution, an approach for generating Bessel beams with a shorter, but tunable focal length is presented. A physical axicon was combined with an SLM. A holographic image of a negative axicon is put on the SLM to generate a ring beam, which is focused by a subsequent physical axicon to get a small focal diameter. Thus, different sized high aspect ratio micro holes can be drilled without using any moving components. KW - Bessel beam KW - Micro drilling KW - Axicon KW - Spatial light modulator KW - Beam shaping KW - Bessel-Bündel KW - Axicon KW - Strahlformung, Laser Y1 - 2023 VL - 2023 IS - 154 SP - 1 EP - 9 PB - LiM 2023 Proceedings ER - TY - JOUR A1 - Flachs, Dennis A1 - Zhukov, Sergey A1 - Zech, Isabella A1 - Schreck, Timo A1 - Belle, Stefan A1 - von Seggern, Heiinz A1 - Kupnik, Mario A1 - Altmann, Alexander Anton A1 - Thielemann, Christiane T1 - Enzymatic Self-Degradable PLA-Based Electrets JF - Journal of Polymers and the Environment N2 - In recent years, the demand for sustainable and degradable materials and electronic devices has increased significantly. Among a range of biodegradable polymers, poly(lactic acid) (PLA) is a good alternative to conventional petrol-based polymers because of its attractive mechanical properties and its easy processability. Recently, PLA has also been described as a promising dielectric material with piezoelectric and electret properties. We expect that PLA—after further optimization— will play an important role as a material for environmentally friendly sensors in the future, where first applications such as air filters and pressure sensors have already been proposed. However, degradation under normal ambient conditions is very slow, and an accelerated and controllable degradation process is highly desirable for any type of PLA-based sensors. Enzymatic hydrolysis with embedded enzymes has been proposed as an approach to accelerate and control degradation. In this work, we investigate the properties of PLA in terms of dielectric and mechanical properties with a focus on its ability to store charges after the enzyme proteinase K (Trit. album) has been incorporated. Results reveal that proteinase K has a positive effect on the charge stability of solvent-cast PLA electrets after complete evaporation of the solvent. Furthermore, we observed a concentration-dependent acceleration of mass loss in a Tris-HCl buffer. A fast degradation within only one day occurred at a concentration of 6 wt% proteinase K. KW - Biologisch abbaubarer Kunststoff Y1 - 2024 U6 - https://doi.org/Journal of https://doi.org/10.1007/s10924-024-03240-6 VL - 2024 IS - 1 SP - 1 EP - 11 ER - TY - CHAP A1 - Sauer, Timm A1 - Gorks, Manuel A1 - Spielmann, Luca A1 - Hepp, Nils A1 - Zindler, Klaus A1 - Jumar, Ulrich T1 - AI-based control approaches for lateral vehicle guidance of industrial trucks T2 - IFAC WC 2023 – The 22nd World Congress of the International Federation of Automatic Control 2023, Yokohama, Japan, 09.07.2023 - 14.07.2023 N2 - Two different control concepts for the automatic track guidance of forklifts are proposed. Both approaches are based on Reinforcement Learning (RL), a method of Artificial Intelligence (AI), and are able to take into account time-variant parameters, such as the vehicle velocity, and to reduce the influence of the path curvature, the most important disturbance variable of lateral vehicle control. In the first approach, both, the path curvature and the vehicle velocity signal, are provided to the controller in addition to the state variables of the controlled system. By varying the corresponding parameters in the training process, both signals can be considered and the control parameters can be optimized accordingly. In the second approach, several controllers (multi-model concept) considering the path curvature are used and the varying vehicle velocity is taken into account using a gain-scheduling concept. Considering time-variant vehicle parameters and the influence of the disturbance variable during operation, a stable track guidance is guaranteed within the whole speed range of the industrial trucks. KW - Artificial intelligence, Lateral vehicle control, Intelligent transportation systems KW - Flurförderer KW - Künstliche Intelligenz Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S2405896323019092 U6 - https://doi.org/https://doi.org/10.1016/j.ifacol.2023.10.1501. ER - TY - JOUR A1 - Balleis, Kristina A1 - Wagner, Stefan T1 - Haftung für Wildschäden in gemeinschaftlichen Jagdbezirken JF - Zeitschrift für Jagdwissenschaft KW - Jagdrecht KW - Forstrecht Y1 - 1998 VL - 44 IS - Juni SP - 85 EP - 93 ER - TY - JOUR A1 - Balleis, Kristina T1 - Keine Heilbarkeit eines Mangels unzureichender interkommunaler Abstimmung im ergänzenden Verfahren nach §215 a BauGB, Urteilsbesprechung JF - Verwaltungsrecht für die Anwaltspraxis KW - Deutschland, Baugesetzbuch KW - Kommunale Zusammenarbeit Y1 - 2000 VL - 2000 IS - 6 SP - 192 EP - 192 ER - TY - JOUR A1 - Balleis, Kristina T1 - Rechtswidrigkeit einer Vorkaufssatzung zur Sicherung städtebaulicher Entwicklung, Urteilsbesprechung JF - Verwaltungsrecht für die Anwaltspraxis KW - Stadtentwicklung KW - Vorkaufsrecht KW - Rechtswidrigkeit Y1 - 2000 VL - 2000 IS - 5 SP - 155 EP - 155 ER - TY - JOUR A1 - Balleis, Kristina T1 - Zulässigkeit und Notwendigkeit einer landesgesetzlichen Verbandsklage im Wasserrecht JF - Recht der Natur / Schnellbrief KW - Verbandsklage KW - Wasserrecht Y1 - 1997 VL - 1997 IS - 47 SP - 18 EP - 19 ER - TY - BOOK A1 - Balleis, Kristina A1 - Schraml, Ulrich A1 - Wagner, Stefan T1 - Jagdrecht und Verbandsklage : aktuelle Fragen des Jagdrechts und der Mitwirkungs- und Klagerechte von Naturschutzverbänden im Wasserrecht KW - Verbandsklage KW - Jagdrecht KW - Wasserrecht Y1 - 1997 SN - 3-932374-01-0 PB - RIWA-Verlag CY - Augsburg ER - TY - BOOK A1 - Balleis, Kristina A1 - Bieling, Alfons A1 - Hufnagl, Natalie A1 - Kleinschmit von Lengefeld, Andreas A1 - Riehtmüller, Anne A1 - Röhrscheid, Stefan A1 - Suda, Michael A1 - Timinger, Michael A1 - Wagner, Stefan A1 - Wiegmann, Stefanie T1 - Rechtliche und fachliche Aspekte des Erhalts schützenswerter Wälder KW - Forstschutz KW - Waldpflege KW - Forstrecht Y1 - 1995 PB - Fachverband Forst CY - Augsburg ER - TY - BOOK A1 - Wörlen, Rainer A1 - Metzler-Müller, Karin A1 - Kokemoor, Axel A1 - Balleis, Kristina T1 - Schuldrecht BT KW - Deutschland KW - Schuldrecht KW - Besonderer Teil Y1 - 2022 SN - 978-3-8006-6546-4 PB - Vahlen CY - München ER - TY - BOOK A1 - Wörlen, Rainer A1 - Metzler-Müller, Karin A1 - Balleis, Kristina A1 - Kokemoor, Axel T1 - BGB AT KW - Deutschland KW - Bürgerliches Recht KW - Allgemeiner Teil Y1 - 2023 SN - 978-3-8006-6833-5 PB - Vahlen CY - München ER - TY - BOOK A1 - Wörlen, Rainer A1 - Metzler-Müller, Karin A1 - Balleis, Kristina A1 - Kokemoor, Axel T1 - Schuldrecht AT KW - Deutschland KW - Schuldrecht KW - Allgemeiner Teil Y1 - 2023 SN - 978-3-8006-7242-4 PB - Vahlen CY - München ER - TY - CHAP A1 - Rötzel, Peter A1 - Fehrenbacher, Dennis T1 - Information Overload in Decision Support Systems T2 - International Symposium on Accounting Information Systems KW - Information Overload KW - Information Systems KW - Controlling KW - Entscheidungsunterstützungssystem KW - Information KW - Überlastung Y1 - 0024 VL - 2024 CY - Paphos ER - TY - JOUR A1 - Gvozdovskyy, Igor A1 - Bratova, Daria A1 - Kazantseva, Z. A1 - Malyuta, S. A1 - Lytvyn, Petro A1 - Schwarz, Simon A1 - Hellmann, Ralf T1 - Light-controllable hybrid aligning layer based on LIPSS on sapphire surface and PVCN-F film JF - Journal of Molecular Liquids N2 - The creation of aligning layers for the uniform orientation of liquid crystals is significant for both research and the application of liquid crystals. For all applications, the creation of aligning layers possessing controllable characteristics such as azimuthal and polar anchoring energies, easy-axis of director alignment and pretilt angle, in the same way as it is achieved by using photoaligning layers processed by light, is very important. Here, aligning properties of hybrid aligning layers created on the basis of sapphire surfaces additionally coated by photoaligning layer of PVCN-F are studied. These hybrid layers possess the properties of the nano-structured sapphire layer and the photosensitive PVCN-F layer, and complement each other. The irradiation time dependence of the azimuthal anchoring energy of the hybrid layers is studied. By using certain experimental conditions during irradiation of hybrid layers, e.g., polarization of light and irradiation time, a minimum value of the azimuthal anchoring energy, close to zero, was obtained. Atomic force microscope studies of the irradiated hybrid layers were also carried out. It was found that the behavior of the contact angle of nematic droplets placed on treated sapphire surfaces are in good agreement with properties of hybrid aligning layers and parameters of structuring surface obtained from AFM images. KW - Flüssigkristall KW - Saphir KW - Kristallfläche Y1 - 2023 U6 - https://doi.org/10.1016/j.molliq.2023.122623 VL - 387 IS - keine SP - 122623 EP - 122623 ER - TY - BOOK A1 - Borgeest, Kai T1 - 内燃机测量技术和试验台架 KW - Verbrennungsmotor KW - Prüfstand KW - Verbrennungsanalyse KW - Abgasemission KW - internal combustion engines KW - engine testing KW - exhaust gas analysis KW - combustion analysis Y1 - 2023 SN - 978-7-111-71807-9 PB - China Machine Press ER - TY - JOUR A1 - Häfner, Tom A1 - Bischoff, Kay A1 - Helm, Jonas A1 - Kunz, Tim A1 - Rung, Stefan A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - KEINE FREISCHALTUNG - Urheberrecht 0 bei Dokument mit Volltext Picosecond laser microvia drilling of ABF material using MHz burst mode JF - Materials Research Express N2 - We report on a comprehensive study of laser percussion microvia drilling of Ajinomoto build-up film (ABF) material using an ultrashort pulsed laser in MHz burst mode. After laser processing, microvia drilling quality is being evaluated by the fabricated diameter and taper using laser scanning microscopy and metallography. The influences of the incubation effect, heat accumulation and shielding effects as a result of pulse to pulse interactions are being discussed on the ablation threshold, penetration depth and laser microvia drilling quality. We find that an increasing heat accumulation in MHz burst mode processing is responsible for the void formation and delamination of the insulating ABF layer. Therefore, the parameter clearance is introduced to evaluate these effects on the microvia sidewalls. For a comparable clearance, applying 2 intra-burst pulses achieves an average reduced taper of down to 19.5% compared to single pulse mode. At the same time, a reduced laser drilling time of 16.7% per microvia highlights the enormous potential of the MHz burst mode for laser drilling of ABF material in printed circuit board fabrication. KW - Ultrakurzzeitlaser KW - Pikosekundenbereich Y1 - 2023 VL - 10 IS - 9 SP - 096301 EP - 096311 ER - TY - JOUR A1 - Zettl, Julian A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Fundamental Considerations and Analysis of the Energy Distribution in Laser Turning with Ultrashort Laser Pulses JF - mdpi Micromachines N2 - This article discusses the process of the laser turning of rotational symmetric, cylindrical components using ultrashort laser pulses with respect to the geometrical conditions and the resulting energy distribution during the laser turning process. As a result, process predictions and potential process optimizations are feasible. Particular attention is drawn to the laser spot formation on the cylindrical surface of the work piece in conjunction with the positioning of the laser beam relative to the rotation axis of the specimen. Based on fundamental calculations and experimental results, an optimum processing strategy is discussed, whereat the use of a trepanning optic in the laser turning process and the forming of a particular surface structure is additionally being issued. KW - ultrashort pulse laser KW - laser turning KW - tangential processing KW - trepanning optic KW - Ultrakurzzeitlaser Y1 - 2023 UR - https://www.mdpi.com/2072-666X/14/10/1838 U6 - https://doi.org/10.3390/mi14101838 VL - 14 IS - 10 SP - 1 EP - 15 ER - TY - CHAP A1 - Bischoff, Kay A1 - Mücke, Dominik A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - UV-Femtosecond-Laser Structuring of Silicon Carbide T2 - International Congress on Applications of Lasers & Electro-Optics (ICALEO) 2023 N2 - We report on ultraviolet ultrashort pulsed laser processing of silicon carbide. Laser ablated cavities are evaluated with respect to their ablation rates, surface roughness and overall quality by varying the laser pulse fluence. Using this type of laser, high edge quality and surface roughness down to 107 nm can be achieved with an ablation efficiency of up to 0.228 mm 3 W −1 min −1. Functional surfaces are produced by generating laser induced periodic surface structures. The comparison with infrared wavelength underlines the advantages of the ultraviolet wavelength for laser micro machining this material. Significant differences with respect to the measured ablation depths and roughness as well as generated micro-and nanostructures appear. While infrared ablation is dominated by a chipping mechanism above a critical fluence of 9.93 Jcm −2 , higher ablation rates are observed with strong quality losses at the same time. In comparison to the infrared emission wavelength, in general , a significantly higher processing quality is achieved with the ultraviolet emission wavelength. In addition, the influence of spot size and repetition rate in UV processing is investigated. By increasing these parameters, a process acceleration without quality losses is enabled. The generation of a sophisticated microstructure exemplifies the advantages of processing silicon carbide with the UV laser reported here. KW - Femtosekundenlaser KW - Siliciumcarbid Y1 - 2023 ER - TY - CHAP A1 - Bischoff, Kay A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Acceleration of Femtosecond Reductive Laser Sintering of Copper(II) Oxide for Conductive Copper Patterns on Cyclic Olefin Copolymers T2 - International Congress on Applications of Lasers & Electro-Optics (ICALEO) 2023 N2 - We report on the acceleration of femtosecond reductive laser sintering of copper (II) oxide on the surface of transparent cyclic olefin copolymers (COC) by varying the focus size to generate metallic copper (Cu) layers. By using different focusing conditions, different process speeds are achieved, and the structural accuracies are controlled. The formation of Cu lines is observed for different focus sizes at various scan speeds, which is attributed to laser exposure duration and chemical reaction time. The formed lines are categorized and measured by optical microscopy and provide the basis for two-dimensional Cu surfaces. By hatching, high quality conductive films are produced with an increased focus diameter of up to 400 µm at a scan speed of 400 mm/s and a hatch distance of 250 µm resulting in a multiple increased process speed by a factor of thirteen compared to previous research. Using 4-tip measurement , a low sheet resistance of 0.165 Ω/sq was validated on these Cu films, which have an atomic Cu content of 89.5%. KW - Femtosekundenlaser Y1 - 2023 ER - TY - JOUR A1 - Dobrovolskij, Dascha A1 - Stark, Hans-Georg T1 - Synthetic demand data generation for individual electricity consumers: Inpainting JF - Energy and AI N2 - In this contribution we deal with the problem of producing “reasonable” data, when considering recorded energy consumption data, which are at certain sections incomplete and/or erroneous. This task is important, when energy providers employ prediction models for expected energy consumption, which are based on past recorded consumption data, which then of course should be reliable and valid. In a related contribution Yilmaz (2022), GAN-based methods for producing such “artificial data” have been investigated. In this contribution, we describe an alternative and complementary method based on signal inpainting, which has been successfully applied to audio processing Lieb and Stark (2018). After giving a short overview of the theory of proximity-based convex optimization, we describe and adapt an iterative inpainting scheme to our problem. The usefulness of this approach is demonstrated by analyzing real-world-data provided by a German energy supplier. KW - Energieverbrauch KW - Energieversorgungsunternehmen Y1 - 2024 VL - 15 IS - Januar 2024 SP - 100312 EP - 100320 ER - TY - JOUR A1 - Lieb, Florian A1 - Knopp, Tobias T1 - A wavelet-based sparse row-action method for image reconstruction in magnetic particle imaging JF - Medical Physics N2 - Purpose Magnetic particle imaging (MPI) is a preclinical imaging technique capable of visualizing the spatio-temporal distribution of magnetic nanoparticles. The image reconstruction of this fast and dynamic process relies on efficiently solving an ill-posed inverse problem. Current approaches to reconstruct the tracer concentration from its measurements are either adapted to image characteristics of MPI but suffer from higher computational complexity and slower convergence or are fast but lack in the image quality of the reconstructed images. Methods In this work we propose a novel MPI reconstruction method to combine the advantages of both approaches into a single algorithm. The underlying sparsity prior is based on an undecimated wavelet transform and is integrated into a fast row-action framework to solve the corresponding MPI minimization problem. Results Its performance is numerically evaluated against a classical FISTA (Fast Iterative Shrinkage-Thresholding Algorithm) approach on simulated and real MPI data. The experimental results show that the proposed method increases image quality with significantly reduced computation times. Conclusions In comparison to state-of-the-art MPI reconstruction methods, our approach shows better reconstruction results and at the same time accelerates the convergence rate of the underlying row-action algorithm. KW - Wavelet KW - Bildgebendes Verfahren KW - Magnetpartikelbildgebung Y1 - 2021 UR - https://doi.org/10.1002/mp.14938 VL - 48 IS - 7 SP - 3893 EP - 3903 ER - TY - JOUR A1 - Bischoff, Kay A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Preparation of Dispersed Copper(II) Oxide Nanosuspensions as Precursor for Femtosecond Reductive Laser Sintering by High-Energy Ball Milling JF - Nanomaterials N2 - This contribution demonstrates and discusses the preparation of finely dispersed copper(II) oxide nanosuspensions as precursors for reductive laser sintering (RLS). Since the presence of agglomerates interferes with the various RLS sub-processes, fine dispersion is required, and oversized particles must be identified by a measurement methodology. Aside from the established method of scanning electron microscopy for imaging individual dried particles, this work applies the holistic and statistically more significant laser diffraction in combination with dynamic image analysis in wet dispersion. In addition to direct ultrasonic homogenization, high-energy ball milling is introduced for RLS, to produce stable nanosuspensions with a high fine fraction, and, above all, the absence of oversize particles. Whereas ultrasonic dispersion stagnates at particle sizes between 500 nm and 20 μm, even after 8 h, milled suspension contains a high proportion of finest particles with diameters below 100 nm, no agglomerates larger than 1 μm and a trimodal particle size distribution with the median at 50 nm already, after 100 min of milling. The precursor layers produced by doctor blade coating are examined for their quality by laser scanning microscopy. The surface roughness of such a dry film can be reduced from 1.26 μm to 88 nm by milling. Finally, the novel precursor is used for femtosecond RLS, to produce homogeneous, high-quality copper layers with a sheet resistance of 0.28 Ω/sq and a copper mass concentration of 94.2%. KW - Laserstrahlsintern KW - Femtosekundenlaser Y1 - 2023 U6 - https://doi.org/https://doi.org/10.3390/nano13192693 VL - 13 IS - 19 SP - 2693 EP - 2693 ER - TY - JOUR A1 - Bischoff, Kay A1 - Kefer, Stefan A1 - Wienke, Alexander A1 - Overmeyer, Ludger A1 - Kaierle, Stefan A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Integration of Bragg gratings in aerosol-jetted polymer optical waveguides for strain monitoring capabilities JF - Optics Letters N2 - We demonstrate and discuss the integration of Bragg gratings in aerosol-jetted polymer optical waveguides, produced in the optical assembly and connection technology for component-integrated bus systems (OPTAVER) process. By using a femtosecond laser and adaptive beam shaping, an elliptical focal voxel generates different types of single pulse modification by nonlinear absorption in the waveguide material, which are arranged periodically to form Bragg gratings. Integration of a single grating structure or, alternatively, an array of Bragg grating structures in the multimode waveguide yields a pronounced reflection signal with typical multimodal properties, i.e., a number of reflection peaks with non-Gaussian shapes. However, the main wavelength of reflection, located around 1555 nm, is evaluable by means of an appropriate smoothing algorithm. When loaded by mechanical bending, a pronounced Bragg wavelength shift of this reflected peak up to 160 pm is detected. This demonstrates that the additively manufactured waveguides can be used not only for signal transmission but also as a sensor. KW - Bragg-Reflektor KW - Lichtwellenleiter Y1 - 2023 U6 - https://doi.org/https://doi.org/10.1364/OL.481801 VL - 48 IS - 7 SP - 1778 EP - 1781 ER - TY - CHAP A1 - Franz, Daniel A1 - Mücke, Dominik A1 - Kunz, Tim A1 - Rung, Stefan A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - UV picosecond laser drilling of ABF film material for printed circuit boards using laser burst mode and beam shaping T2 - International Congress on Applications of Lasers & Electro-Optics (ICALEO) 2023 N2 - We report on an experimental study of laser microvia percussion drilling of Ajinomoto build-up film (ABF) material using an ultrashort pulsed laser in the ultraviolet region. In order to optimize the drilling quality in terms of the fabricated taper and microvia diameter, the MHz burst mode is used in combination with both a Gaussian and a top-hat laser intensity distribution. To evaluate the influence of the top-hat beam shape on defocusing, microvias were drilled at different z-positions in the range of 200 μm evenly distributed around the focal plane. The drilling quality was evaluated by laser scanning microscopy and metallography. When using a top-hat beam shape, a reduced taper of down to 26.8 % on average is achieved compared to a Gaussian beam. For the application of 3 intra-burst pulses, we find an improvement of the taper by 11.6% compared to the single pulse mode due to the increasing heat accumulation. Using a top-hat beam shape in combination with the MHz burst mode, an 18.2 % reduction in laser drilling time for a microvia with a similar taper is remarkable, demonstrating the high potential for scaling throughput in electronics manufacturing. KW - Pikosekundenbereich KW - Laserbohren Y1 - 2023 ER - TY - JOUR A1 - Bischoff, Kay A1 - Mücke, Dominik A1 - Roth, Gian-Luca A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - UV-Femtosecond-Laser Structuring of Cyclic Olefin Copolymer JF - Polymers N2 - We report on the laser ablation of cyclic olefin copolymer using an amplified ultrashort pulsed laser in the ultraviolet spectral range. In addition to a high ablation depth per laser-structured layer up to 74 μm at a fluence of 22 J cm−2, an excellent mean roughness 𝑅𝑎 of laser-patterned surfaces down to 0.5 μm is demonstrated. Furthermore, with increasing fluence, increasing ablation efficiencies up to 2.5 mm3 W−1 min−1 are determined. Regarding the quality of the ablation, we observed steep ablation flanks and low debris formation, though for fluences above 10.5 J cm−2 the formation of troughs was observed, being attributed to multiple reflections on the ablation flanks. For comparison, laser ablation was performed under identical conditions with an infrared laser wavelength. The results highlight that UV ablation exhibits significant advantages in terms of ablation efficiency, surface roughness and quality. Moreover, our results show that a larger UV focus spot accelerates the ablation process with comparable quality, paving the way for high-power UV ultrashort pulsed lasers towards an efficient and qualitative tool for the laser machining of cyclic olefin copolymer. The production of complex microfluidics further underlines the suitability of this type of laser. KW - Femtosekundenlaser Y1 - 2022 U6 - https://doi.org/https://doi.org/10.3390/polym14142962 VL - 14 IS - 14 SP - 2962 EP - 2962 ER - TY - JOUR A1 - Franz, Daniel A1 - Yang, Yongting A1 - Michel, Luis A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Evaluation of an ultrashort pulsed laser robot system for flexible and large-area micromachining JF - Journal of Laser Applications N2 - We report for the first time on the realization, characterization and application of an ultrashort pulsed laser robot system for flexible and large-area 2D and 3D laser micromachining with 6 articulated axes. To characterize the dynamic positioning of the laser beam during and after axes movement, CMOS image sensors were integrated into the beam path. A method introduced for the alignment of the optical axes allows a reduction of the deviations in laser beam positioning to less than 141.8 ± 92.9 μm within a 110° rotation range of axis 4. In addition, a high laser beam positioning repeatability of less than 102.2 μm is demonstrated over a total period of 14 h for a movement of axis 5 within a range of 0° to 90°. Initial laser cutting, laser structuring and laser marking applications on automotive dashboards and glass substrates are presented for flexible and large area 2D and 3D manufacturing. By applying a special laser cutting strategy for processing AF 32 eco thin glass, high cutting quality is achieved with a taper of up to 96.3% without the generation of cracks, demonstrating the innovative potential of the high-precision laser robot system. Nonetheless, different identified inherent influences of each axis 1–5 during robot axis movement demand for an innovative beam stabilization concept to achieve high precision in laser beam positioning. KW - Ultrakurzzeitlaser KW - Industrieroboter Y1 - 2023 N1 - Proceedings of the International Congress of Applications of Lasers & Electro-Optics (ICALEO 2023) VL - 35 IS - 4 SP - 042057 EP - 042065 ER - TY - CHAP A1 - Döhring, Thorsten A1 - Stieglitz, Veronika A1 - Friedrich, Peter A1 - Burwitz, Vadim A1 - Jelinek, Martin A1 - Hudec, Rene T1 - Testing of lobster-eye type telescopes with X-rays and visible light T2 - SPIE Proceedings N2 - Reflective coatings for astronomical X-ray optics were developed at the “Aschaffenburg Competence Center for Astronomical and Space Instrumentation” (ACCASI) since several years. As part of a Bavarian-Czech cooperation between the Technical University of Aschaffenburg and the Czech Technical University of Prague, now two mechanically identical telescopes were built. One telescope optic was equipped with conventional gold-coated mirrors, manufactured by the Czech project partners. The 34 X-ray mirrors of the second telescope use an innovative coating system made of chromium and iridium, which was applied at the Aschaffenburg coating laboratory. Both telescopes are designed according to the bionic principle of a reflecting lobster eye. The optics works with two consecutive reflections on mutually perpendicular mirror surfaces. This enables a large field of view with many square degrees in diameter, which, however, comes at the price of a reduced angular resolution. An extensive X-ray characterization of these telescopes was carried out at the PANTER test facility of MPE, which simulates parallel starlight incident on the telescopes. The telescopes have an angular resolution of about 4 arc minutes in X-rays and a focal length of about 2 meters. Furthermore, the used X-ray mirrors reflect and focus visible light as well and this functionality in the optical regime was checked in laboratory tests. Now another test campaign was done to examine the telescope resolution for real objects of the visible sky and the imaging properties for star constellations. Such functional tests by observing astronomical objects of the visible sky may simplify and accelerate the development of X-ray telescopes for satellite applications. KW - X-rays KW - Telescopes KW - X-ray telescopes KW - Reflection KW - Mirrors KW - Röntgenteleskop Y1 - 2023 U6 - https://doi.org/https://doi.org/10.1117/12.2665429 VL - 2023 IS - 12576 SP - 1257606-1 EP - 1257606-5 PB - SPIE ER - TY - JOUR A1 - Raiyn, Jamal A1 - Weidl, Galia T1 - Predicting Autonomous Driving Behavior through Human Factor Considerations in Safety-Critical Events JF - Smart Cities N2 - This paper investigates the ability of autonomous driving systems to predict outcomes by considering human factors like gender, age, and driving experience, particularly in the context of safety-critical events. The primary objective is to equip autonomous vehicles with the capacity to make plausible deductions, handle conflicting data, and adjust their responses in real-time during safety-critical situations. A foundational dataset, which encompasses various driving scenarios such as lane changes, merging, and navigating complex intersections, is employed to enable vehicles to exhibit appropriate behavior and make sound decisions in critical safety events. The deep learning model incorporates personalized cognitive agents for each driver, considering their distinct preferences, characteristics, and requirements. This personalized approach aims to enhance the safety and efficiency of autonomous driving, contributing to the ongoing development of intelligent transportation systems. The efforts made contribute to advancements in safety, efficiency, and overall performance within autonomous driving systems. To describe the causal relationship between external factors like weather conditions and human factors, and safety-critical driver behaviors, various data mining techniques can be applied. One commonly used method is regression analysis. Additionally, correlation analysis is employed to reveal relationships between different factors, helping to identify the strength and direction of their impact on safety-critical driver behavior. Keywords: car following; decision making; driving behavior; naturalistic driving studies; safety-critical events; cognitive vehicles 1. Introduction Despite the increasing prevalence of vehicle automation, the persistently high number of car crashes remains a concern. Safety-critical events in human-driven scenarios have become more intricate and partially uncontrollable due to unforeseen circumstances. Investigating human driving behavior is imperative to establish traffic baselines for mixed traffic, encompassing traditional, automated, and autonomous vehicles (AVs). Various factors, such as weather conditions affecting visibility in longitudinal car-following (CF) behavior [1,2], influence human driving behavior [3]. Car-following behavior, illustrating how a following vehicle responds to the lead vehicle in the same lane, is a crucial aspect. Existing car-following models often make assumptions about homogeneous drivers, neglecting significant heterogeneity in driving experience, gender, character, emotions, and sociological, psychological, and physiological traits. Failing to account for this heterogeneity hampers a comprehensive understanding of car-following behavior, limiting model accuracy and applicability. In the development of more realistic car-following models for mixed traffic, acknowledging the diversity among drivers is crucial. By including individual variations such as risk-taking tendencies, reaction times, decision-making processes, and driving styles, the modeling of real-world driving complexities can be improved. Simplifying drivers into a few categories overlooks the richness and variety of their characteristics, prompting the need for a more comprehensive approach to capture nuances within different driver profiles. To address these Smart Cities KW - Autonomes Fahrzeug KW - Mensch-Maschine-Kommunikation Y1 - 2024 UR - https://www.mdpi.com/2624-6511/7/1/18 U6 - https://doi.org/https://doi.org/10.3390/ smartcities7010018 VL - 7 IS - 1 SP - 460 EP - 474 ER - TY - CHAP A1 - Kefer, Stefan A1 - Schmauss, Bernhard A1 - Hellmann, Ralf T1 - Sapphire-Based Planar Bragg Grating Devices T2 - 28th International Conference on Optical Fiber Sensors N2 - This study reports on the long-term stability and the high-temperature capability of sapphire-based photonic crystal waveguides with integrated Bragg gratings. Furthermore, their Bragg grating reflectivity as well as their temperature sensitivity is quantified. KW - Bragg-Reflektor KW - Wellenleiter Y1 - 2023 SN - 978-1-957171-30-2 U6 - https://doi.org/10.1364/OFS.2023.W2.4 ER - TY - CHAP A1 - Kefer, Stefan A1 - Pape, Natalie A1 - Schmauss, Bernhard A1 - Hellmann, Ralf T1 - Fabrication of Lattice-Like Waveguides in Planar Cyclic Olefin Copolymers T2 - 28th International Conference on Optical Fiber Sensors N2 - This work demonstrates the femtosecond laser-based fabrication of lattice-like waveguides in planar cyclic olefin copolymers. An overview of the fabrication process is provided and waveguiding in the C-band is proven via optical near-field analysis. KW - Wellenleiter KW - Femtosekundenlaser Y1 - 2023 SN - 978-1-957171-30-2 U6 - https://doi.org/10.1364/OFS.2023.Th6.69 ER - TY - JOUR A1 - Kefer, Stefan A1 - Limbach, Tobias A1 - Pape, Natalie A1 - Klamt, Kathrin A1 - Schmauss, Bernhard A1 - Hellmann, Ralf T1 - Birefringence in Injection-Molded Cyclic Olefin Copolymer Substrates and Its Impact on Integrated Photonic Structures JF - Polymers N2 - This contribution quantifies the birefringence within injection-molded cyclic olefin copolymer plates and discusses its impact on the mechanical properties of the plates. It also focuses on the impact of birefringence on integrated waveguides and Bragg gratings and provides fabrication guidelines for such structures. The anisotropy in all three dimensions of the workpiece is examined by means of polarimetry and a prism coupler. It is found that the birefringence is inhomogenously distributed within the workpieces, whereas the maximum birefringence not only varies locally, but also depends on the observation direction. Overall, a maximum birefringence of 10 × 10−4 is found at the plate’s surface near the injection gate. The anisotropy then reduces exponentially towards the center of the workpiece and saturates at 1.8 × 10−4, in a depth of 0.4 mm. Thus, the birefringence strongly affects near-surface photonic structures. It is found that, depending on their orientation and the local birefringence of the substrate, waveguides and Bragg gratings fabricated with comparable parameters behave completely differently in terms of polarization-dependent optical attenuation, cross-sectional intensity distribution and Bragg reflection signal. For example, the support of the TM mode can vary between total loss and an optical attenuation of 0.9 dB × cm−1. In consequence, this study underlines the importance of quantifying the birefringent state of an injection-molded cyclic olefin copolymer workpiece if it is supposed to serve as a substrate for integrated photonic structures. The study furthermore demonstrates that birefringence effects can be omitted by burying the photonic structures deeper into the volume of the thermoplastic. KW - cyclic olefin copolymer KW - birefringence KW - integrated photonics KW - Bragg grating KW - injection molding KW - Bragg-Reflektor KW - Wellenleiter KW - Doppelbrechung Y1 - 2024 UR - https://www.mdpi.com/2073-4360/16/2/168 U6 - https://doi.org/10.3390/polym16020168 VL - 16 IS - 2 SP - 168 EP - 168 ER - TY - CHAP A1 - Normann, Marc A1 - Haug, Jim A1 - Valencia, Yeimy A1 - Abke, Jörg A1 - Hagel, Georg ED - Mottock, Jürgen ED - Hagel, Georg T1 - Adaptive Learning Path Sequencing Based on Learning Styles within N-dimensional Spaces T2 - ECSEE '23: Proceedings of the 5th European Conference on Software Engineering Education N2 - Planning adaptive learning paths for students’ progress throughout a course can be a challenging task, although it can be helpful for their learning progress. Within the HASKI-System, students should be able to get their own, personalized learning paths. In this paper, we present an approach towards the learning path sequencing problem. This idea is based on a novel proposal for arranging learning objects in a multi-dimensional space, bringing the relationship and similarities of these objects into a new relationship. We show, that we can use both, the Ant Colony Optimization Algorithm and the Genetic Algorithm with the idea of the Traveling-Salesman-Problem and get results, that are comparable with a proposed literature-based adaption mechanism. Nevertheless, the learning paths are all personalized based on the Felder & Silverman Learning Style Model and the hyperspace model will allow us later on to include more dimensions for other influencing factors. KW - Learning Path Sequencing KW - Adaptive Learning Path KW - Ant Colony KW - Genetic Algorithm KW - Adaptive Learning Environment KW - Lernstil KW - Lernerfolg Y1 - 2023 UR - https://dl.acm.org/doi/abs/10.1145/3593663.3593676 U6 - https://doi.org/https://doi.org/10.1145/3593663.3593676 VL - 2023 SP - 56 EP - 64 ER - TY - JOUR A1 - Trent, Davis A1 - Thielemann, Christiane A1 - Monici, Monica T1 - How are cell and tissue structure and function influenced by gravity and what are the gravity perception mechanisms? JF - npj Microgravity N2 - Progress in mechanobiology allowed us to better understand the important role of mechanical forces in the regulation of biological processes. Space research in the field of life sciences clearly showed that gravity plays a crucial role in biological processes. The space environment offers the unique opportunity to carry out experiments without gravity, helping us not only to understand the effects of gravitational alterations on biological systems but also the mechanisms underlying mechanoperception and cell/tissue response to mechanical and gravitational stresses. Despite the progress made so far, for future space exploration programs it is necessary to increase our knowledge on the mechanotransduction processes as well as on the molecular mechanisms underlying microgravity-induced cell and tissue alterations. This white paper reports the suggestions and recommendations of the SciSpacE Science Community for the elaboration of the section of the European Space Agency roadmap “Biology in Space and Analogue Environments” focusing on “How are cells and tissues influenced by gravity and what are the gravity perception mechanisms?” The knowledge gaps that prevent the Science Community from fully answering this question and the activities proposed to fill them are discussed. KW - Zellkultur KW - Schwere KW - Raumfahrtbiologie Y1 - 0024 UR - https://rdcu.be/dyCjL U6 - https://doi.org/10.1038/s41526-024-00357-9 VL - 2014 IS - 10 / 16 SP - 1 EP - 7 ER - TY - CHAP A1 - Voigt, Jorrit A1 - Moeckel, Michael T1 - Modelling dynamic 3D heat transfer in laser material processing based on physics informed neural networks N2 - Machine learning algorithms make predictions by fitting highly parameterized nonlinear functions to massive amounts of data. Yet those models are not necessarily consistent with physical laws and offer limited interpretability. Extending machine learning models by introducing scientific knowledge in the optimization problem is known as physics-based and data-driven modelling. A promising development are physics informed neural networks (PINN) which ensure consistency to both physical laws and measured data. The aim of this research is to model the time-dependent temperature profile in bulk materials following the passage of a moving laser focus by a PINN. The results from the PINN agree essentially with finite element simulations, proving the suitability of the approach. New perspectives for applications in laser material processing arise when PINNs are integrated in monitoring systems or used for model predictive control. KW - Neuronales Netz KW - Laserbearbeitung Y1 - 2022 UR - https://www.researchgate.net/publication/364325407_Modelling_dynamic_3D_heat_transfer_in_laser_material_processing_based_on_physics_informed_neural_networks U6 - https://doi.org/10.1051/epjconf/202226602010 ER - TY - CHAP A1 - Akcatepe, Osman A1 - Moeckel, Michael T1 - Hybrid Physics-Inspired Machine Learning Framework for Predictive Maintenance of Forklift Chains: Leveraging Sensor Data Characteristics N2 - Bridging the gap between physics-based modeling and data-driven machine learning promises to reduce the amount of training data required and to improve explainability in predictive maintenance applications. For a small fleet of industrial forklift trucks, we develop a physically inspired framework for predicting remaining useful life (RUL) for selected components by integrating physically motivated feature extraction, degradation modelling and machine learning. The discussed approach is promising for situations of limited data availability or large data heterogeneity, which often occurs in fleets of customized vehicles optimized for particular tasks. KW - Maschinelles Lernen KW - Gabelstapler Y1 - 2023 UR - https://ieeexplore.ieee.org/abstract/document/10375057/authors#authors U6 - https://doi.org/10.1109/ICCMA59762.2023.10375057 ER - TY - JOUR A1 - Voigt, Jorrit A1 - Moeckel, Michael T1 - Benchmarking a multi-layer approach and neural network architectures for defect detection in PBF-LB/M JF - Materials Today Communications N2 - The substitution of expensive non-destructive material testing by data-based process monitoring is intensively explored in quality assurance for additive manufactured components. Machine learning show promising results for defect detection but require conceptual adaption to layer wise manufacturing and line scanning patterns in laser powder bed fusion. A multi-layer approach to co-register µ-computer tomography measurements with process monitoring data is developed and a workflow for automatic data set generation is implemented. The objective of this research is to benchmark the volumetric multi-layer approach and specifically selected deep learning methods for defect detection. The volumetric approach shows superior results compared to single slice monitoring. All investigated structured neural network topologies deliver similar performance. KW - Neuronales Netz KW - Maschinelles Lernen KW - Fehlererkennung Y1 - 2022 UR - https://www.sciencedirect.com/science/article/pii/S2352492822017196?via%3Dihub U6 - https://doi.org/https://doi.org/10.1016/j.mtcomm.2022.104878 VL - 2022 IS - 33/104878 SP - * EP - * ER -