TY - INPR A1 - Weiherer, Maximilian A1 - Eigenberger, Andreas A1 - Brébant, Vanessa A1 - Prantl, Lukas A1 - Palm, Christoph T1 - Learning the shape of female breasts: an open-access 3D statistical shape model of the female breast built from 110 breast scans N2 - We present the Regensburg Breast Shape Model (RBSM) – a 3D statistical shape model of the female breast built from 110 breast scans, and the first ever publicly available. Together with the model, a fully automated, pairwise surface registration pipeline used to establish correspondence among 3D breast scans is introduced. Our method is computationally efficient and requires only four landmarks to guide the registration process. In order to weaken the strong coupling between breast and thorax, we propose to minimize the variance outside the breast region as much as possible. To achieve this goal, a novel concept called breast probability masks (BPMs) is introduced. A BPM assigns probabilities to each point of a 3D breast scan, telling how likely it is that a particular point belongs to the breast area. During registration, we use BPMs to align the template to the target as accurately as possible inside the breast region and only roughly outside. This simple yet effective strategy significantly reduces the unwanted variance outside the breast region, leading to better statistical shape models in which breast shapes are quite well decoupled from the thorax. The RBSM is thus able to produce a variety of different breast shapes as independently as possible from the shape of the thorax. Our systematic experimental evaluation reveals a generalization ability of 0.17 mm and a specificity of 2.8 mm for the RBSM. Ultimately, our model is seen as a first step towards combining physically motivated deformable models of the breast and statistical approaches in order to enable more realistic surgical outcome simulation. KW - Statistical shape mode KW - Surgical outcome simulation KW - 3D breast scan registration KW - Non-rigid surface registration KW - Breast imaging Y1 - 2021 ER - TY - VIDEO A1 - Auer, Simon A1 - Reinker, Lukas A1 - Süß, Franz A1 - Kubowitsch, Simone A1 - Krutsch, Werner A1 - Weber, Markus A1 - Renkawitz, Tobias A1 - Dendorfer, Sebastian T1 - Webcast: Effect of mental demand on leg loading in highly dynamic motion N2 - Football players have a high risk of leg muscle injuries, especially when exposed to mental stress. Injuries to muscles of the thigh are common in amateur and professional football, representing almost a third of all injuries. These injuries occur primarily in non-contact situations and from overuse. They can lead to a range of costs, including financial costs associated with treatment as well as those associated with long-term recovery, and absence from training and/or competition. Further, there is a high risk of injury recurrence and subsequent injury. KW - Webcast KW - AnyBody KW - Stress KW - Football KW - Speedcourt Y1 - 2020 UR - https://www.youtube.com/watch?v=uSc_9XlnkaA ER - TY - VIDEO A1 - Melzner, Maximilian A1 - Engelhardt, Lucas T1 - AnyBody Webcast - A new musculoskeletal AnyBody™ detailed hand model Y1 - 2020 UR - https://www.youtube.com/watch?v=E4xnbjRJYm8&t=631s ER - TY - GEN A1 - Melzner, Maximilian A1 - Ismail, Khaled M. A1 - Rušavý, Zdeněk A1 - Kališ, Vladimír A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - Musculoskeletal Lower Back Load of Accoucheurs During Delivery T2 - 26th Congress of the European Society of Biomechanics, July 11-14, 2021, Milan, Italy N2 - With the progress in modern medicine, it was possible to significantly reduce the risks of birth for mother and child. One aspect that has received less attention so far is the risk of injury to the accoucheurs (obstetricians and midwives) during the birth process. Indeed, studies indicate that 92% of midwives suffer from musculoskeletal disorders, with the lower back being the main cause of complaints (72%). The aim of this study was to investigate two commonly used postural techniques used by accoucheurs during childbirth and to analyze the resulting load on the lower back using the AnyBodyTM musculoskeletal simulation software. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-20208 CY - Milan ER - TY - GEN A1 - Auer, Simon A1 - Reinker, Lukas A1 - Dendorfer, Sebastian T1 - Evaluation of muscle recruitment and muscle models in musculoskeletal simulation of dynamic motion T2 - 26th Congress of the European Society of Biomechanics, July 11-14, 2021, Milan, Italy N2 - Musculoskeletal simulation plays an increasingly important role in sports biomechanics. In the last years, the field of application widened from orthopaedics and ergonomics to sports [1]. A muscle recruitment algorithm with a quadratic objective function is usually used to calculate muscle activity in dynamic movements. The agreement of calculated and measured thigh muscle activity has already been investigated [2]. They found a strong agreement for sprinting and running, while the correlation decreased for side-cutting manoeuvres. Nevertheless, the influence of different muscle recruitment criteria on muscle activity in dynamic musculoskeletal simulations is currently unknown. Hence, this study aimed to analyse the effect of different muscle recruitment criteria and muscle models on the correlation of numerical and measured muscle activity in highly dynamic movements. KW - esb KW - biomechanics KW - muscle recruitment Y1 - 2021 UR - https://esbiomech.org/conference/archive/2021milan/Contribution_1719.pdf CY - Milan ER - TY - INPR A1 - Weiß, Martin Georg T1 - Optimization of Cartesian Tasks with Configuration Selection N2 - A basic task in the design of an industrial robot application is the relative placement of robot and workpiece. Process points are defined in Cartesian coordinates relative to the workpiece coordinate system, and the workpiece has to be located such that the robot can reach all points. Finding such a location is still an iterative procedure based on the developers' intuition. One difficulty is the choice of one of the several solutions of the backward transform of a typical 6R robot. We present a novel algorithm that simultaneously optimizes the workpiece location and the robot configuration at all process points using higher order optimization algorithms. A key ingredient is the extension of the robot with a virtual prismatic axis. The practical feasibility of the approach is shown with an example using a commercial industrial robot. KW - optimization KW - Intralogistik KW - Industrieroboter KW - Programmgenerierung KW - Nichtlineare Optimierung KW - robotics Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-20176 UR - https://arxiv.org/pdf/1811.07137.pdf ER - TY - JOUR A1 - Klotz, Stefan A1 - Westner, Markus A1 - Strahringer, Susanne T1 - Critical Success Factors of Business-managed IT: It Takes Two to Tango JF - Information Systems Management N2 - This paper identifies critical success factors of Business-managed IT based on case study results. Four groups of critical success factors emerge: (1) general approach to Business-managed IT/Business-managed IT strategy, (2) Business-managed IT project prerequisites/Business-managed IT team, (3) Business-managed IT project execution and outcome, and (4) information technology management for Business-managed IT. The results suggest that bilateral responsibility between the business unit and the IT organization is the most favorable governance option for Business-managed IT. KW - Betriebliches Informationssystem KW - Strategisches Management KW - Erfolgsfaktor KW - Fallstudie KW - Business-managed IT KW - Shadow IT KW - critical success factors KW - IT governance KW - application governance Y1 - 2022 U6 - https://doi.org/10.1080/10580530.2021.1938300 VL - 39 IS - 3 SP - 220 EP - 240 PB - Taylor&Francis ER - TY - CHAP A1 - Brosig, Christoph A1 - Westner, Markus A1 - Strahringer, Susanne ED - Borštnar, Mirjana Kljajić T1 - Linking IT assets and competitive advantage - IT capabilities of servitized business models T2 - 34th Bled eConference Digital Support from Crisis to Progressive Change: June 27 - 30, 2021, Online: Conference Proceedings N2 - This paper connects research from business model innovation and information systems by exploring critical IT capabilities for servitized business models. The adoption of servitized business models is a major business model innovation strategy. At the same time, digitalization drives the evolution of IT capabilities at these business models. Scholars argue that it remains unclear how IT capabilities enable servitized business models to build a competitive advantage by achieving cost advantages or differentiation. This paper explores IT capabilities that enable building a competitive advantage for servitized business models based on a qualitative analysis of multiple published case studies. The authors identify configurations of IT capabilities among servitized business models. The findings contribute to servitization research by exploring IT capabilities and how they are combined among servitized business models. The insights help practitioners deploy digital technologies and IT assets effectively as building blocks of IT capabilities to advance their servitized business model. KW - resource-based view KW - IT capability KW - digital servitization KW - competitive advantage KW - Geschäftsmodell KW - Innovation KW - Hybrides Leistungsbündel KW - Informationstechnik Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-20158 UR - https://press.um.si/index.php/ump/catalog/book/581 SN - 978-961-286-485-9 SP - 111 EP - 123 ER - TY - JOUR A1 - Wulf, Frederik A1 - Westner, Markus A1 - Strahringer, Susanne T1 - Cloud Computing Adoption: A Literature Review on What Is New and What We Still Need to Address JF - Communications of the Association for Information Systems N2 - Research on cloud computing (CC) recently emerged congruently with the technology’s importance for organizations at a fast pace. This makes it difficult for practitioners to obtain a consolidated overview of what determines CC adoption based on the numerous papers in this regard. Moreover, for further research in the field to add value, it is necessary to identify what still needs to be addressed. In this vein, we conducted a descriptive review of 39 papers, integrating the results of a previous review on 23 papers from 2014, to compare findings across studies. We identify 44 determinant factors that exhibit consistent directional influence on the dependent meta-variable “CC adoption”, extending previous literature reviews with regard to asset, client, and environmental characteristics. We then critically reviewed the research landscape to identify what is there, and what is not yet covered: Future research should specifically regard the adoption of Infrastructure-, Platform-, and Everything-as-a-Service, private, hybrid, and multi-cloud deployment, investigate vendor, solution, and individual characteristics, analyzing information systems, or the decision-maker. KW - Cloud Computing KW - Literaturbericht Y1 - 2021 U6 - https://doi.org/10.17705/1CAIS.04843 SN - 1529-3181 VL - 48 IS - 1 SP - 523 EP - 561 PB - Association for Information Systems, AIS ER - TY - JOUR A1 - Wünsche, Isabel A1 - Brinkmann, Melanie A1 - Pfingsten, Andrea A1 - Borgetto, Bernhard T1 - Selbsthilfe von Menschen mit einer rheumatischen Erkrankung JF - internistische praxis N2 - Durch die wissenschaftlich fundierte Darstellung der Selbsthilfe (SH) bei rheumatischen Erkrankungen sollen mögliche Handlungsunsicherheiten im Umgang mit Selbsthilfegruppen (SHG) in der täglichen Praxis verringert werden. Welche Mechanismen in SHG wirken, wurde bisher nicht ausreichend wissenschaftlich untersucht. Im Zusammenhang mit dem gesicherten Wissen über die salutogenen und tertiärpräventiven Wirkungsweisen von Kommunikation und sozialen Bindungen, kann aus dem Stand der Selbsthilfeforschung jedoch ein allgemeines heuristisches Modell der Wirkung von SHG abgeleitet werden, welches kurz erläutert wird. Von der Weltgesundheitsorganisation werden rheumatische Erkrankungen als mehr oder weniger klar definierte Erkrankungen der Gelenke, gelenkumgebenden Strukturen und Muskel- oder Bindegewebe beschrieben, die zu schmerzhaften, häufig chronischen Einschränkungen des Bewegungsapparates führen können. Neben der fachärztlichen Versorgung besteht durch die Deutsche Rheuma-Liga (DRL) ein flächendeckendes SH-Angebot für Betroffene. Insbesondere SHG tragen zur gegenseitigen sozialen Unterstützung und zur Informationsaneignung bei den Betroffenen und in deren sozialen Umfeld bei. Sind die Ergebnisse und Schlussfolgerungen der Studien zu den Wirkungen von SH bei rheumatischen Erkrankungen aufgrund methodischer Schwierigkeiten der Wirkungsforschung auch limitiert, heben doch die meisten Forscher hervor, dass die Unterstützung durch SHG allein und in Kombination mit einer professionellen Versorgung neben vielen Einzelaspekten auch die Lebensqualität erhöht. KW - akuter Gelenkrheumatismus KW - Rheumatismus KW - Selbsthilfe KW - Muskelrheumatismus KW - rheumatische Erkrankungen KW - Rheumatismus KW - Selbsthilfe KW - Wirkmechanismen Y1 - 2019 SN - 0009–4846 VL - 61 IS - 1 SP - 56 EP - 67 PB - Mediengruppe Oberfranken - Fachverlage ER - TY - JOUR A1 - Melzner, Maximilian A1 - Suess, Franz A1 - Dendorfer, Sebastian T1 - The impact of anatomical uncertainties on the predictions of a musculoskeletal hand model – a sensitivity study JF - Computer Methods in Biomechanics and Biomedical Engineering N2 - Outputs of musculoskeletal models should be considered probabilistic rather than deterministic as they are affected by inaccuracies and estimations associated with the development of the model. One of these uncertainties being critical for modeling arises from the determination of the muscles' line of action and the physiological cross-sectional area. Therefore, the aim of this study was to evaluate the outcome sensitivity of model predictions from a musculoskeletal hand model in comparison to the uncertainty of these input parameters. For this purpose, the kinematics and muscle activities of different hand movements (abduction of the fingers, abduction of the thumb, and flexion of the thumb) were recorded. One thousand simulations were calculated for each movement using the Latin hypercube sampling method with a corresponding variation of the muscle origin/insertion points and the cross-sectional area. Comparing the standard hand to simulations incorporating uncertainties of input parameters shows no major deviations in on- and off-set time point of muscle activities. About 60% of simulations are located within a ± 30% interval around the standard model concerning joint reaction forces. The comparison with the variation of the input data leads to the conclusion that the standard hand model is able to provide not over-scattered outcomes and, therefore, can be considered relatively stable. These results are of practical importance to the personalization of a musculoskeletal model with subject-specific bone geometries and hence changed muscle line of action. KW - Biomechanik KW - Simulation Y1 - 2021 U6 - https://doi.org/10.1080/10255842.2021.1940974 SN - 1476-8259 N1 - Corresponding author: Maximilian Melzner VL - 25 IS - 2 SP - 156 EP - 164 PB - Taylor & Francis ER - TY - JOUR A1 - Souza Jr., Luis Antonio de A1 - Mendel, Robert A1 - Strasser, Sophia A1 - Ebigbo, Alanna A1 - Probst, Andreas A1 - Messmann, Helmut A1 - Papa, João Paulo A1 - Palm, Christoph T1 - Convolutional Neural Networks for the evaluation of cancer in Barrett’s esophagus: Explainable AI to lighten up the black-box JF - Computers in Biology and Medicine N2 - Even though artificial intelligence and machine learning have demonstrated remarkable performances in medical image computing, their level of accountability and transparency must be provided in such evaluations. The reliability related to machine learning predictions must be explained and interpreted, especially if diagnosis support is addressed. For this task, the black-box nature of deep learning techniques must be lightened up to transfer its promising results into clinical practice. Hence, we aim to investigate the use of explainable artificial intelligence techniques to quantitatively highlight discriminative regions during the classification of earlycancerous tissues in Barrett’s esophagus-diagnosed patients. Four Convolutional Neural Network models (AlexNet, SqueezeNet, ResNet50, and VGG16) were analyzed using five different interpretation techniques (saliency, guided backpropagation, integrated gradients, input × gradients, and DeepLIFT) to compare their agreement with experts’ previous annotations of cancerous tissue. We could show that saliency attributes match best with the manual experts’ delineations. Moreover, there is moderate to high correlation between the sensitivity of a model and the human-and-computer agreement. The results also lightened that the higher the model’s sensitivity, the stronger the correlation of human and computational segmentation agreement. We observed a relevant relation between computational learning and experts’ insights, demonstrating how human knowledge may influence the correct computational learning. KW - Deep Learning KW - Künstliche Intelligenz KW - Computerunterstützte Medizin KW - Barrett's esophagus KW - Adenocarcinoma KW - Machine learning KW - Explainable artificial intelligence KW - Computer-aided diagnosis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-20126 SN - 0010-4825 VL - 135 SP - 1 EP - 14 PB - Elsevier ER - TY - JOUR A1 - Haug, Sonja A1 - Vetter, Miriam A1 - Weber, Karsten T1 - Gebäudesanierung zwischen Energieeffizienz und Sozialverträglichkeit BT - Zwei empirische Fallstudien JF - TATuP - Zeitschrift für Technikfolgenabschätzung in Theorie und Praxis N2 - Die Akzeptanz unter Bewohnern und Bewohnerinnen gewinnt bei hoch komplexen, technisch anspruchsvollen energetischen Sanierungen als „Innovationsmotor“ zunehmend an Relevanz. Der Beitrag basiert auf zwei Fallstudien zur partizipativen Nutzereinbindung bei energetischen Sanierungen im genossenschaftlichen Wohnbau historischer Stadtquartiere in Regensburg. Neben einer sozialverträglichen Sanierung wurde jeweils ein hohes Maß an Energieeffizienz bei den technischen Lösungen ange-strebt. Haushaltsbefragungen und qualitative Interviews zeigen die hohe Akzeptanz von Sanierungsmaßnahmen, sofern die Senkung der Energiekosten die erhöhte Miete kompensiert. Abschließend werden Akzeptanzfaktoren wie Partizipation, Vertrauen, Sozialverträglichkeit und Autarkie erörtert. T2 - Building restoration between energy efficiency and user acceptance KW - Altbaumodernisierung KW - Energieeinsparung KW - Sozialverträglichkeit KW - Fallstudie KW - energy-efficient building restoration KW - user acceptance KW - household survey KW - historic quarter KW - renewable energy Y1 - 2020 U6 - https://doi.org/10.14512/tatup.29.3.56 SN - 2567-8833 VL - 29 IS - 3 SP - 56 EP - 63 PB - oekom-Verlag ER - TY - JOUR A1 - Haug, Sonja A1 - Vetter, Miriam T1 - Altersgerechtes Wohnen im Quartier JF - Standort - Zeitschrift für angewandte Geographie N2 - Im Alter nimmt das Quartier aufgrund geringerer Aktionsradien an Bedeutung zu. Der Beitrag befasst sich mit der Frage, welche Besonderheiten sich bei Senioren-Haushalten im Hinblick auf Wohnen und soziale Teilhabe zeigen. Aus dem Projekt MAGGIE werden Ergebnisse einer schriftlichen Haushaltsbefragung (N=195) in der Wohngenossenschaft Margaretenau Regensburg dargestellt. Hierbei wird auf die aktuelle und zukünftige Wohnsituation, den Veränderungsbedarf, den Wunsch nach Gemeinschaftsangeboten und die soziale Einbettung eingegangen. Es zeigt sich eine geringe Veränderungsbereitschaft und ein überdurchschnittlich hohes Maß an lokalem Sozialkapital. Am Ende werden Schlussfolgerungen für das Sanierungs- und Quartiersmanagement gezogen. T2 - Age-appropriate living in the neighborhood KW - Alter KW - Wohnen KW - Stadtviertel KW - Sozialraum KW - Senioren KW - Wohnsituation KW - Sozialraum KW - Lokales Sozialkapital KW - Quartiersgestaltung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-20050 SN - 1432-220X N1 - Corresponding author: Sonja Haug VL - 45 SP - 11 EP - 17 PB - Springer Nature ER - TY - JOUR A1 - Milewski, Nadja A1 - Haug, Sonja T1 - Religious Diversity and Women’s Attitudes Toward Using Assisted Reproductive Technologies BT - Insights from a Pilot Study in Germany JF - Journal of Religion and Demography N2 - This study examines women’s attitudes toward the own use of assisted reproductive technologies (ART) by their religious affiliation in Germany. The social relevance of ART is increasing in Western countries due to overall low birth rates, a high rate of childlessness, and a gap between the desired and the actual numbers of children. Previous literature has been scarce, however, on attitudes toward ART, and religious diversity has not been included in studies on ART. Our analysis is based on data collected in a pilot study in 2014 and 2015. The sample includes 944 women aged 18 to 50 living in Germany. The results show that Muslim women were significantly more likely than Christian women to say they would consider using ART; having no religious affiliation was associated with the least open attitude toward ART usage. KW - Reproduktionsmedizin KW - Frau KW - Religion KW - Deutschland KW - social attitudes KW - fertility KW - ART KW - reproductive health KW - Germany Y1 - 2020 U6 - https://doi.org/10.1163/2589742X-12347104 SN - 2589-742X VL - 7 IS - 1 SP - 150 EP - 168 PB - Brill ER - TY - JOUR A1 - Weber, Markus A1 - Suess, Franz A1 - Jerabek, Seth A1 - Meyer, Matthias A1 - Grifka, Joachim A1 - Renkawitz, Tobias A1 - Dendorfer, Sebastian T1 - Kinematic pelvic tilt during gait alters functional cup position in total hip arthroplasty JF - Journal of Orthopaedic Research N2 - Static pelvic tilt impacts functional cup position in total hip arthroplasty (THA). In the current study we investigated the effect of kinematic pelvic changes on cup position. In the course of a prospective controlled trial postoperative 3D-computed tomography (CT) and gait analysis before and 6 and 12 months after THA were obtained in 60 patients. Kinematic pelvic motion during gait was measured using Anybody Modeling System. By fusion with 3D-CT, the impact of kinematic pelvic tilt alterations on cup anteversion and inclination was calculated. Furthermore, risk factors correlating with high pelvic mobility were evaluated. During gait a high pelvic range of motion up to 15.6° exceeding 5° in 61.7% (37/60) of patients before THA was found. After surgery, the pelvis tilted posteriorly by a mean of 4.0 ± 6.6° (p < .001). The pelvic anteflexion led to a mean decrease of −1.9 ± 2.2° (p < .001) for cup inclination and −15.1 ± 6.1° (p < .001) for anteversion in relation to the anterior pelvic plane (APP). Kinematic pelvic changes resulted in a further change up to 2.3° for inclination and up to 12.3° for anteversion. In relation to the preoperative situation differences in postoperative cup position ranged from −4.4 to 4.6° for inclination and from −7.8 to 17.9° for anteversion, respectively. Female sex (p < .001) and normal body weight (p < .001) correlated with high alterations in pelvic tilt. Kinematic pelvic changes highly impact cup anteversion in THA. Surgeons using the APP as reference should aim for a higher anteversion of about 15° due to the functional anteflexion of the pelvis during gait. KW - component position KW - gait analysis KW - kinematics KW - pelvic tilt KW - total hip arthroplasty KW - Hüftgelenkprothese KW - Haltungsfehler KW - Hüftgelenkpfanne Y1 - 2021 U6 - https://doi.org/10.1002/jor.25106 SN - 1554-527X VL - 40 IS - 4 SP - 846 EP - 853 PB - Wiley ER - TY - JOUR A1 - Herrmann, Frank A1 - Reiter, Christian T1 - Losbildung bei einem Engpass an Lagerfläche im Presswerk eines Automobilzulieferers JF - Anwendungen und Konzepte der Wirtschaftsinformatik N2 - Die im Presswerk eines Automobilzulieferers benötigte Lagerfläche stieg in den letzten Jahren so gewaltig an, dass die bisher verwendeten Produktionslose manuell reduziert werden mussten, um überhaupt einlagern zu können. Die dadurch sich ergebenden höheren Kosten werden quantifiziert. Zur Verbesserung werden die strukturellen Unterschiede zwischen den neuen Losen und den durch ein Standardverfahren in ERP-Systemen gelieferten Losen analysiert. Diese Unterschiede zeigen, dass die 2. Stufe in diesem 2-stufigen Vorgehen – 1. Los berechnen und dann 2. dieses geeignet reduzieren – die Entscheidungen der ersten Stufe in der Regel vollständig revidiert. Ein integrativer Ansatz ist erforderlich. Dies erfolgt durch ein lineares Optimierungsmodell mit beschränkter Lager fläche. Das ILOG - Tool, ein Standardwerkzeug zur Lösung linearer Optimierungsmodelle, löst dieses Modell innerhalb von Minuten. Dass mit diesem optimalen Verfahren die Kosten substantiell verringert werden, wird simulativ nachgewiesen. Seit einigen Monaten wird dieses Verfahren im Rahmen einer rollenden Planung im Presswerk eingesetzt. Eine rollende Planung bewirkt in der Regel einen Verlust in der Lösungsgüte. In diesem Fall wurden nahezu optimale Lösungen erreicht, mit denen die Kosten substantiell verringert wurden. Die Werksleitung und die Mitarbeiter sind mit diesem neuen Verfahren sehr zufrieden. KW - Engpass an Lagerfläche KW - signifikant beschränkter Lagerplatz KW - ERP-System KW - SAP System KW - Losgrößenverfahren KW - Silver Meal-Verfahren KW - Feste Losgröße KW - Wagner-Whitin-Verfahren KW - Optimierungs - modell mit beschränktem Lagerplatz Y1 - 2019 U6 - https://doi.org/10.26034/lu.akwi.2019.3238 SN - 2296-4592 VL - 10 IS - 10 SP - 54 EP - 71 PB - AKWI ER - TY - CHAP A1 - Borgetto, Bernhard A1 - Wünsche, Isabel A1 - Schwinn, Silke A1 - Pfingsten, Andrea ED - Razum, Oliver ED - Kolip, Petra T1 - Selbsthilfe T2 - Handbuch Gesundheitswissenschaften KW - Medizinische Versorgung KW - Selbsthilfe KW - Gesundheitssystem KW - Soziale Unterstützung Y1 - 2020 SN - 978-3-7799-4960-2 SP - 932 EP - 953 PB - Beltz Juventa CY - Weinheim, Basel ET - 7., überarbeitete Auflage ER - TY - CHAP A1 - Pfingsten, Andrea A1 - Borgetto, Bernhard ED - Baas, Jens T1 - Akademisierung der therapeutischen Gesundheitsberufe T2 - Perspektive Gesundheit 2030. Gesellschaft, Politik, Transformation KW - Heilberuf KW - Akademisierung Y1 - 2021 SN - 9783954666331 SP - 173 EP - 183 PB - Medizinisch Wissenschaftliche Verlagsgesellschaft CY - Berlin ER - TY - CHAP A1 - Börsch-Supan, Axel A1 - Düzgün, Ismail A1 - Weiss, Matthias ED - Broeders, Dirk ED - Eijffinger, Sylvester C.W. ED - Houben, Aerdt T1 - Labor Productivity in an Aging Society T2 - Frontiers in Pension Finance N2 - How to deliver adequate pension benefits at reasonable costs is a huge challenge confronting our ageing societies. This book delivers a comprehensive overview of the latest insights into pension finance, pension system design, pension governance and risk based supervision. It combines state-of-the-art analyses with innovative policy proposals to increase the efficiency and resilience of pension systems and to advance these systems’ contribution to global financial stability. Renowned pension experts offer cutting-edge guidance for future decision making and the development of best practices. This exciting exploration of the frontiers in pension finance highlights key aspects of securing long term retirement provisions. Y1 - 2008 U6 - https://doi.org/10.4337/9781847209924.00013 SP - 83 EP - 98 PB - Edward Elgar CY - Cheltenham ER - TY - JOUR A1 - Weiss, Matthias T1 - On the Evolution of Wage Inequality in Acemoglu's Model of Directed Technical Change JF - Applied Economics Letters N2 - In Acemoglu's model of directed technical change, the skill-premium increases in consequence of an increase in the relative supply of skilled labour. In this article, I argue that other measures of wage inequality such as the Gini-coefficient do not necessarily rise as well. The Gini-coefficient depends positively on the skill-premium, but the effect of an increase in the relative supply of skilled labour is ambiguous. A simulation of Acemoglu's model shows that the growth in the relative supply of skilled labour has led to increased wage inequality in the past, but will lead to decreasing wage inequality in the future. Y1 - 2009 U6 - https://doi.org/10.1080/13504850701206452 VL - 16 IS - 6 SP - 591 EP - 595 PB - Taylor & Francis ER - TY - JOUR A1 - Weiss, Matthias A1 - Garloff, Alfred T1 - Skill Biased Technological Change and Endogenous Benefits BT - The Dynamics of Unemployment and Wage Inequality JF - Applied Economics N2 - In this article, we study the effect of skill-biased technological change on unemployment and wage inequality in the presence of a link between social benefits and average income. In this case, an increase in the productivity of skilled workers, and hence their wage, leads to an increase in average income and hence in benefits. The increased fallback income, in turn, makes unskilled workers ask for higher wages. As higher wages are not justified by corresponding productivity increases, unemployment rises. Generally, we show that skill-biased technological change leads to increasing unemployment of the unskilled and to a moderately increasing wage inequality when benefits are endogenous. The model provides a theoretical explanation for diverging dynamics in wage inequality and unemployment under different social benefits regimes. Analysing the social legislation in 14 countries, we find that benefits are linked to the evolution of average income in Continental Europe but not in the US and the UK. Given this institutional difference, our model predicts that skill-biased technological change leads to rising unemployment in Continental Europe and rising wage inequality in the US and the UK. Y1 - 2011 U6 - https://doi.org/10.1080/00036840802599933 VL - 43 IS - 7 SP - 811 EP - 821 PB - Taylor & Francis ER - TY - THES A1 - Weiss, Matthias T1 - Labor Market Effects of Technological Change and Working Time Reduction BT - Some Insights from a General Equilibrium Perspective Y1 - 2003 ER - TY - JOUR A1 - Börsch-Supan, Axel A1 - Düzgün, Ismail A1 - Weiss, Matthias T1 - Altern und Produktivität BT - Eine neue Sichtweise der Arbeitsproduktivität JF - Personalführung N2 - Der Zusammenhang zwischen Alter und Leistungsfähigkeit von Beschäftigten wird in den verschiedensten Disziplinen untersucht - mit zum Teil recht unterschiedlichen Ergebnissen. Dieser Beitrag gibt einen Überblick über die Literatur und diskutiert die Notwendigkeit einer neuen Sicht der Produktivitätsmessung. Bisherige Studien beschäftigen sich mit der Messung der individuellen Produktivität. In einer modernen arbeitsteiligen Gesellschaft realisiert sich die Arbeitsproduktivität allerdings weniger in der Einzelperson als vielmehr im Zusammenwirken von jüngeren (innovativen, flexiblen?) und älteren (erfahrenen?) Mitarbeitern. Y1 - 2006 IS - 07 SP - 74 EP - 81 ER - TY - CHAP A1 - Greiner, Nina A1 - Currle, Edda A1 - Ettl, Katrin A1 - Frommeld, Debora A1 - Haug, Sonja A1 - Kudienko, Natalie A1 - Lauer, Norina A1 - Lichtenauer, Norbert A1 - Meussling-Sentpali, Annette A1 - Middel, Luise A1 - Mohr, Christa A1 - Pfingsten, Andrea A1 - Popp, Christof A1 - Raptis, Georgios A1 - Weber, Karsten T1 - Technik im Alltag – Technik zum Leben : Telepräsenzgestützte Pflege und Therapie bei Schlaganfallpatient*innen T2 - Kann Digital Pflege?: Clusterkonferenz ,,Zukunft der Pflege", 3., September 2020, Nürnberg N2 - Vorgestellt wird das Forschungsvorhaben des interdisziplinären Forschungsprojekts „DeinHaus 4.0 – Telepräsenzroboter für die Pflege und Unterstützung von Schlaganfallpatientinnen und -patienten (TePUS)“. Über geeignete Robotersysteme sollen den Proband*innen individuell abgestimmte Angebote aus den Bereichen Telenursing und Teletherapie zur Verfügung gestellt werden. Hierbei werden einerseits Telepräsenzsitzungen durchgeführt, anderseits kommen verschiedene Apps zum Einsatz. Die Interventionen werden mittels eines Mixed-Methods-Ansatzes evaluiert. Begleitend werden Technikakzeptanz und Nutzungsbereitschaft untersucht. T2 - Technology in Everyday Life - Technology for Living : Telenursing and Telepractice for Stroke Patients KW - Schlaganfall KW - Schlaganfall KW - Patient KW - Roboter KW - Telepräsenz KW - Telemedizin KW - Telepräsenzroboter KW - Telenursing KW - Teletherapie KW - Technikakzeptanz Y1 - 2021 UR - https://pflege-professionell.at/konferenz SN - 2710-3048 VL - Konferenzband Teil 1 SP - 57 EP - 61 CY - Königstetten, Österreich ER - TY - CHAP A1 - Grunow, Dieter A1 - Pfingsten, Andrea A1 - Borgetto, Bernhard ED - Hurrelmann, Klaus ED - Razum, Oliver T1 - Selbsthilfe T2 - Handbuch Gesundheitswissenschaften N2 - Die Gesundheitsversorgung kommt ohne die Eigenverantwortung, Selbsthilfe und aktive Mitarbeit der Patient*innen nicht aus. Die medizinische und psychosoziale Versorgung stößt bei chronischen Erkrankungen und bei Behinderungen an ihre Grenzen. Zusätzlich zu dem professionellen Versorgungssystem leisten daher individuelle und gemeinschaftliche Selbsthilfe einen wissenschaftlich insgesamt gut belegten, wichtigen Beitrag zur Krankheitsbewältigung und zur Verbesserung der Lebensqualität von Menschen mit chronischen Erkrankungen und Behinderungen; Belastungen und „Nebenwirkungen“ scheinen sich in engen Grenzen zu halten. Neben gegenseitiger Hilfe in Selbsthilfegruppen gehören Interessenvertretung, Beratung und Information durch und für Betroffene, Kooperation mit dem Versorgungssystem und zunehmend virtuelle Selbsthilfe zu den wichtigsten Selbsthilfe-Aktivitäten. Die gemeinschaftliche Selbsthilfe wird finanziell in erheblichem Umfang durch die gesetzlichen Krankenkassen gefördert. Viele Selbsthilfegruppen erhalten Unterstützung durch lokale Selbsthilfekontaktstellen und überregionale Selbsthilfeorganisationen. Die gemeinschaftliche Selbsthilfe hat sich von einer anfangs primär emanzipativen und medizinkritischen Bewegung zu einem immer stärker integralen Bestandteil des deutschen Gesundheitssystems entwickelt und ist damit facettenreicher geworden. Sie hat damit aber auch ihren Schwerpunkt auf eine Weise verschoben, dass ihre zukünftige Entwicklung im Spannungsfeld weiterer funktionaler Differenzierung und Institutionalisierung, Selbstauflösung und Neustart sowie als Auslöser für Anpassungsprozesse bei den anderen, sie umgebenden sozialen Systemen, diskutiert wird. KW - Medizinische Versorgung KW - Selbsthilfe KW - Gesundheitssystem KW - Soziale Unterstützung Y1 - 2016 SN - 9783779943549 SP - 961 EP - 983 PB - Beltz CY - Weinheim ET - 6. durchgesehene Auflage ER - TY - JOUR A1 - Wulf, Frederik A1 - Westner, Markus A1 - Schön, Maximilian A1 - Strahringer, Susanne A1 - Loebbecke, Claudia T1 - Cloud-Computing-Nutzung bei der Continental AG JF - Wirtschaftsinformatik & Management N2 - Dieser Artikel richtet sich an IT-Führungskräfte, die die Nutzung von Cloud Computing (CC) in ihren Unternehmen fördern wollen. Eine Fallstudie des Konzerns Continental AG zeigt, wie Continental CC in großem Maßstab für die Organisation nutzbar machte. Das Unternehmen ging dabei in drei Schritten vor: Nach einer Experimentierphase wurde der Einsatz zunehmend professionalisiert und CC abschließend umfangreich nutzbar gemacht. Hieraus können drei Hand-lungsempfehlungen für Führungskräfte abgeleitet werden: (1) die CC-Strategie nach dem Delivery-Modell differenzieren, (2) in die Integration von Infrastructure-as-a-Service (IaaS)- und Platform-as-a-Service (PaaS)-Anbietern investieren und (3) den Wissenstransfer innerhalb des Unternehmens fördern, um Veränderungen zu ermöglichen. KW - Cloud Computing KW - Unternehmen Y1 - 2021 U6 - https://doi.org/10.1365/s35764-021-00342-x SN - 1867-5905 VL - 13 IS - 4 SP - 302 EP - 309 PB - Springer Nature ER - TY - JOUR A1 - Scheer, Clara A1 - Kubowitsch, Simone A1 - Dendorfer, Sebastian A1 - Jansen, Petra T1 - Happy Enough to Relax? How Positive and Negative Emotions Activate Different Muscular Regions in the Back - an Explorative Study JF - Frontiers in Psychology N2 - Embodiment theories have proposed a reciprocal relationship between emotional state and bodily reactions. Besides large body postures, recent studies have found emotions to affect rather subtle bodily expressions, such as slumped or upright sitting posture. This study investigated back muscle activity as an indication of an effect of positive and negative emotions on the sitting position. The electromyography (EMG) activity of six back muscles was recorded in 31 healthy subjects during exposure to positive and negative affective pictures. A resting period was used as a control condition. Increased muscle activity patterns in the back were found during the exposure to negative emotional stimuli, which was mainly measured in the lumbar and thorax regions. The positive emotion condition caused no elevated activity. The findings show that negative emotions lead to increased differential muscle activity in the back and thus corroborate those of previous research that emotion affects subtle bodily expressions. KW - electromyography KW - muscle activity KW - emotion KW - sadness KW - happiness KW - embodiment Y1 - 2021 U6 - https://doi.org/10.3389/fpsyg.2021.511746 SN - 1664-1078 VL - Volume 12 IS - May 2021 PB - Frontiers Media ER - TY - CHAP A1 - Figas, Paula A1 - Knörl, Susanne A1 - Mörtlbauer, Stefanie A1 - Sedelmaier, Yvonne A1 - Schroll-Decker, Irmgard ED - Hagel, Georg ED - Mottok, Jürgen T1 - Developing Software Engineering Education as a Didactical Discipline in its own right T2 - 1st European Conference on Software Engineering Education (ECSEE) at Seon Monastery, Germany N2 - Simultaneously to the growing significance of the discipline software engineering (SE) also its education becomes more important. This reinforces the need of a theoretical foundation of software engineering education, but there is still a lack of scientifically justified didactical concepts. In the context of the project EVELIN (Experimental Improvement in Learning Software Engineer-ing) the authors want to give a decisive impulse for the development of a “Fachdidaktik software engineering” (FD-SE). In order to compile an adequate theoretical basis for a Fachdidaktik of software engineering “Allgemeine Did-aktik” (AD)1, its relation to “Fachdidaktik” (FD) in general, the special branch of science of software engineering and related scientific disciplines are dis-cussed. This analysis is used to justify the necessity of an autonomous scientific discipline Fachdidaktik software engineering which meets the challenges of teaching and learning software engineering. The main contributions of this pa-per are proposals on how this FD can be built scientifically upon AD, on the one hand, and how it can be implemented by specific didactical approaches for software engineering, on the other hand. KW - Fachdidaktik KW - Software Engineering KW - Lehre KW - Hochschule Y1 - 2014 UR - https://www.researchgate.net/publication/269762126_Developing_Software_Engineering_Education_as_a_Didactical_Discipline_in_its_own_right SP - 1 EP - 15 PB - Shaker Verlag ER - TY - CHAP A1 - Serbun, Pavel A1 - Porshyn, Vitali A1 - Müller, Günter A1 - Mingels, Stephan A1 - Lützenkirchen-Hecht, Dirk A1 - Bachmann, Michael A1 - Düsberg, Felix A1 - Dams, Florian A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Field emission behavior of Au-tip-coated p-type Si pillar structures T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - Precisely aligned high-aspect-ratio (HAR) silicon tip arrays were fabricated using enhanced reactive ion etching with an inductively-coupled-plasma followed by a sharpening oxidation. A gold thin film was then sputtered only on the tips of the HAR structures. Field-emission (FE) properties from Au-coated HAR p-Si tip array cathodes have been systematically investigated by means of field emission scanning microscopy (FESM). A rather high efficiency of the HAR Si structures (71% at 550 V), but limited homogeneous FE with currents of 1-600 nA might be correlated with the varying geometry of the tips and the presence of oxides. I-V measurements of single Au-coated HAR emitters revealed activation effects and the saturation current region at 3 nA. An increase of the saturation current by 4 orders of magnitude was observed during 20 hours of conditioning at constant voltage, which finally resulted in nearly reproducible FN curves with a ß-factor of 473. An excellent stability of the emission current of less than 1 % was obtained during the additional long-time conditioning at constant voltage. Optical switching under halogen lamp illumination resulted in at least 2 times higher saturation currents and showed a linear dependence of the FE current on the light color temperature. KW - field emission KW - p-type Si-pillar array KW - surface oxide effects KW - photoemission Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551516 SN - 2380-6311 SP - 181 EP - 182 PB - IEEE ER - TY - CHAP A1 - Bachmann, Michael A1 - Dams, Florian A1 - Düsberg, Felix A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Extraction of the characteristics of limiting elements from field emission measurement data T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - In this contribution we will present an algorithm to extract the characteristics of non-Fowler-Nordheim (FN) circuit elements from saturation limited field emission (FE) measurement data. The method for calculating the voltage drop on limiting circuit elements is based on circuit theory as well as Newton's method. Since no assumption on the limiting circuit is made, this method is applicable to any FE data showing saturation. To be able to determine the significance of any parameter output, the uncertainties of data and extracted parameters are fully taken into account throughout the algorithm. External serial resistors and a limiting p-doped substrate are analyzed, where the latter shows a diode-like behavior. Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551474 SN - 2380-6311 SP - 81 EP - 82 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Field emission from black silicon structures with integrated gate electrode T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - Black silicon structures with integrated gate electrode were realized by using an improved fabrication process. An enhanced insulation layer was achieved by a combination of dry and wet oxidation, and a gold layer was evaporated as gate electrode. The black silicon structures were prepared with a RIE/ICP etching process at room temperature. Arrays of 16 and 100 apertures with buried p-doped black silicon whiskers have been fabricated. These structures have an emitter height of approximately 1.5 μm with tip radii between 5 nm and 30 nm. The whiskers are surrounded by the gate electrode in a distance of 1.5 μm. Integral field emission measurements yielded an onset voltage of 92 V for 16 apertures and 60 V for 100 apertures for an emission current of 1 nA. Maximum emission currents up to 0.2 μA were observed for the array with 100 apertures at a cathode voltage of 200 V. Stability measurements showed a current fluctuation of ± 21% at a mean value of the emission current of 12 nA over a period of 30 minutes for 16 apertures with b-Si whiskers. KW - field emission KW - black silicon KW - integrated gate electrode Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551532 SN - 2380-6311 SP - 219 EP - 220 PB - IEEE ER - TY - CHAP A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert A1 - Huang, Yifeng A1 - She, Juncong T1 - Gated p-Si field emission cathode applied in an ionization vacuum gauge T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - A commercial Bayard-Alpert ionization vacuum gauge was equipped with a field emission electron source based on a cathode consisting of an array of 16 gated, p-doped, and DLC-coated Si-tips and characterized. An anode current of about 1.3 μA led to an ion current of 7 fA at 3×10 -7 mbar and 0.8 pA at 4×10 -5 mbar. Whereas at pressures higher than 4×10 -5 mbar the emission current of the electron source decreased, the ratio of ion and anode current remained linear. A nearly constant sensitivity of ~ 17 mbar -1 of the ionization vacuum gauge within the investigated pressure range was depicted. KW - field emission KW - field emitter array KW - Si KW - DLC KW - electron source KW - ionization vacuum gauge Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551500 SN - 2380-6311 SP - 145 EP - 146 PB - IEEE ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Field emission from three-dimensional epitaxial grown GaN-microrods T2 - 29th International Vacuum Nanoelectronics Conference (IVNC), 2016, 11-15 July, Vancouver, BC, Canada N2 - A novel three-dimensional epitaxial technique allows on patterned substrates the realization of gallium nitride pillars, also known as nano- and microrods. The typical dimensions of the microrods are in the range of one micron for the radius of the hexagonal footprint and about 10 μm in height. The microrods consist of a semiconductor heterostructure with an n GaN core, a n-GaN shell, a p GaN shell and an intermediate quantum well layer. The field emission properties were investigated in diode configuration by integral field emission measurements in a vacuum chamber at pressures around 10 -9 mbar. The spacer was mica with a thickness of 50 μm. A metallized fine-meshed nitride grid (or a metallized Si-grid) was used as anode. A current of about 1 μA at a voltage of 1250 V (1750 V) was measured. An onset field of about 12.5 MV/m (20 MV/m) and field enhancement factors in the range of 200 to 500 (150 to 300) were found. The investigation with the fine-meshed grid showed an expected pronounced saturation region. KW - field emission KW - GaN KW - LED Y1 - 2016 U6 - https://doi.org/10.1109/IVNC.2016.7551477 SN - 2380-6311 SP - 87 EP - 88 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Mecani, Mirgen A1 - Huang, Yifeng A1 - She, Juncong A1 - Schreiner, Rupert ED - Tiginyanu (Ed.), Ion M. T1 - Field emission properties of ring-shaped Si ridges with DLC coating T2 - Proc. SPIE 10248, Nanotechnology VIII, 102480H (30 May 2017) N2 - We report on the fabrication and the emission characterization of single ring-shaped Si ridges with a coating of diamond-like carbon (DLC). The reactive ion etching and the subsequent inductively coupled plasma step were adjusted to realize ring-shaped Si ridges with a height of 7.5 μm respectively 15 μm and an apex radius of 20 – 25 nm. The samples were coated with a DLC layer (thickness ≈ 2 – 5 nm) by a filtered cathodic vacuum arc deposition system in order to lower the work function of the emitter and to improve the field emission characteristics. The field emission characterizations were done in diode configuration with cathode and anode separated by a 50 μm thick mica spacer. A higher emission current was carried out for the ring-shaped Si ridge in comparison to the point-shaped Si tips due to the increased emission area. The highest emission current of 0.22 μA at 1000 V was measured on a DLC-coated sample with the highest aspect ratio. No degradation of the emission current was observed in the plateau regime during a measurement period of 6 h. Finally, no decreasing performance of the field emission properties was found due to changes in the geometry or destructions. KW - Etching KW - Scanning electron microscopy KW - Silicon carbide KW - Carbon KW - Mica KW - Oxides Y1 - 2017 U6 - https://doi.org/10.1117/12.2265627 VL - 102480H PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - CHAP A1 - Thumann, Philipp A1 - Wagner, Marcus A1 - Suck, Bertram A1 - Meinhardt, Josef A1 - Marburg, Steffen T1 - Explicit and Implicit FE Simulations of Material Tests for Subsequent Durability Analyses T2 - 11th European LS-DYNA Conference, Salzburg N2 - Because of increased stroke rates the loads on forming tools increase too. To ensure a save design of components, durability analyses are intended. For this, simulation results from FE analyses are necessary. Therefore, it is desirable to use elements with quadratic function, because of a good stress approximation.The goal of the described investigation is to show if calculation results created by LS-DYNA [1] can be used for durability analyses. Especially the use of quadratic elements is investigated. For the evaluation, on the one hand explicit FE analyses of a special durability test are carried out. These analyses are validated by available test data. To create results for later durability analyses further FE analyses with implicit time discretisation are carried out. In this paper results of the investigations are presented and evaluated critically. Y1 - 2017 UR - https://www.dynalook.com/conferences/11th-european-ls-dyna-conference/experiments-and-parameter-optimization/explicit-and-implicit-fe-simulations-of-material-tests-for-subsequent-durability-analyses ER - TY - CHAP A1 - Thumann, Philipp A1 - Swidergal, Krzysztof A1 - Wagner, Marcus T1 - Calculation and validation of material tests with specimens made out of filled elastomers T2 - 10th European LS-DYNA Conference 2015, Würzburg N2 - In deep-drawing dies for steel sheet parts of car bodies huge masses are moved. To prevent vibrations, which occur by sudden acceleration or stopping of those masses, elastomeric tubular dampers [1] are used. The dampers are made out of carbon filled elastomers. A good knowledge about the material behaviour of metals is available. But for the numerical investigation of complete deep-drawing dies the elastomeric dampers must be taken into account, too. To characterize the material behaviour of the elastomers tensile tests and pressure tests were carried out. The received material data from the tests were read into LS-DYNA [2]. Simulation models of the tensile test and the pressure test were created for LS-DYNA according to the real dimensions and boundary conditions. For validation purposes, calculations of loading cycles were done to enable a comparison between test data and simulation results. For the calculations the implemented material model *MAT_SIMPLIFIED_RUBBER_WITH_DAMAGE (*MAT_183) was used. The comparison shows a good fitting between the test data and the calculation results with respect to the mechanical material behaviour by using this material model in single loading cases. The settings from the simulations of material tests were transferred to simulations of dampers, which are used in deep-drawing dies. Y1 - 2015 UR - https://www.semanticscholar.org/paper/Calculation-and-validation-of-material-tests-with-Thumann-Swidergal/7502f1c70a07654c8238f4a6bd436aa5bd4c051f ER - TY - CHAP A1 - Koch, F. A1 - Thumann, Philipp A1 - Wagner, Marcus T1 - Simulation with implicit time integration of high loaded areas of a forming tool for large presses using LS-DYNA T2 - 13. LS-DYNA Forum 2014, 6.-8. Oktober, Bamberg Y1 - 2016 ER - TY - CHAP A1 - Meckl, D. A1 - Lubeseder, Christian A1 - Zausinger, C. A1 - Wurmb, Ingo von A1 - Meinhardt, Josef A1 - Swidergal, Krzysztof A1 - Wagner, Marcus T1 - Simulation of press dies for large presses using the flexible multibody dynamics in Recurdyn T2 - 4th RecurDyn TechnologyDays 2014, München Y1 - 2014 ER - TY - CHAP A1 - Bachmann, Michael A1 - Dams, Florian A1 - Düsberg, Felix A1 - Hofmann, Martin A1 - Pahlke, Andreas A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Control of the electron source current T2 - International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg N2 - A control circuit to stabilize the flux of electrons transmitted through an extractor electrode is presented. By controlling the emission current a fluctuation with a standard deviation of 0.015% is observed. However, the achievable stability of the transmitted electron current is limited due to a variation of the extraction grid current ratio showing a standard deviation of 4.33%. By regulating the difference of the emission current and the extraction grid current an improved stability of the transmitted electron current down to a standard deviation of 0.280% is observed. Even with operation at 2 × 10 -5 mbar a standard deviation of 0.558% is achieved. KW - Standards KW - Circuit stability KW - Power system stability KW - Current measurement KW - Voltage measurement KW - Electron sources KW - Stability analysis Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051550 SP - 66 EP - 67 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Benzocyclobutene as a novel integrated spacer material in a field emission electron source T2 - International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg N2 - For the realization of a miniaturized field emission electron source we tested benzocyclobutene (BCB) as a new spacer material between cathode and anode. We fabricated black silicon emitters and characterized the emission behavior with an integrated 5 μm thin and large-area spacer of BCB. The integrated BCB layer allows the realization of a compact electron source with only two components consisting of a cathode with BCB and a grid. The comparison with other spacer materials like polyimide (25 μm thickness) or mica (50 μm thickness) revealed for the cathode with BCB a significantly reduced operational voltage of 240 V for a field emission current of 1 μA. KW - field emission KW - benzocyclobutene KW - integrated spacer KW - electron source KW - black silicon Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051605 SP - 192 EP - 193 PB - IEEE ER - TY - CHAP A1 - Swidergal, Krzysztof A1 - Lubeseder, Christian A1 - Wurmb, Ingo von A1 - Meinhardt, Josef A1 - Wagner, Marcus A1 - Marburg, Steffen T1 - Effiziente Methode zur Bestimmung von dynamischen strukturellen Belastungen in Großpresswerkzeugen T2 - 36. EFB-Kolloquium Blechverarbeitung 2016, Fellbach Y1 - 2016 ER - TY - RPRT A1 - Thumann, Philipp A1 - Swidergal, Krzysztof A1 - Wagner, Marcus ED - Baier, Wolfgang T1 - Experimentelle Ermittlung von Materialkennwerten und numerische Untersuchungen an einem gefüllten Elastomer T2 - Forschungsbericht 2015 / Ostbayerische Technische Hochschule Regensburg Y1 - 2015 UR - https://doi.org/10.35096/othr/pub-1386 SN - 978-3-00-048589-3 SP - 49 EP - 50 ER - TY - JOUR A1 - Swidergal, Krzysztof A1 - Lubeseder, Christian A1 - Wurmb, Ingo von A1 - Lipp, Arnulf A1 - Meinhardt, Josef A1 - Wagner, Marcus A1 - Marburg, Steffen T1 - Experimental and numerical investigation of blankholder’s vibration in a forming tool BT - a coupled MBS-FEM approach JF - Production Engineering - Research and Development N2 - In order to achieve the energy and efficiency goals in modern automotive press shops, press systems with increasingly high stroke rates are being implemented (Meinhardt in proceedings of ACI forming in car body engineering. Bad Nauheim, Germany 2012). As a side effect, the structural dynamic loads on the press and especially on the forming tool increase. Hence, to design reliable and withstanding forming tools, a detailed knowledge of the vibrations and resulting critical loads is essential. In this paper, the main focus is put on the vibration of the blankholder—the heaviest moving component in the forming tool. To predict those vibrations, a coupled multibody-finite element simulation (MBS-FEM) is conducted, which combines rigid and elastic modeling approaches. Also, an experimental validation of the blankholder vibration under operational load is carried out. To compare the numerical and experimental results—both in time and frequency domain—an 1/3-octave analysis of a blankholder’s vibrational speed is performed. The test measurements agree well with the MBS-FEM simulation. KW - Forming tool/die KW - Coupled MBS-FEM simulation KW - Blankholder KW - Vibration KW - Servo press Y1 - 2015 U6 - https://doi.org/10.1007/s11740-015-0640-9 SN - 0944-6524 VL - 9 IS - 5-6 SP - 634 PB - Springer ER - TY - JOUR A1 - Thumann, Philipp A1 - Marburg, Steffen A1 - Meinhardt, Josef A1 - Saubiez, Jean‐Marc A1 - Hoogen, Michael A1 - Suck, Bertram A1 - Wagner, Marcus T1 - Frequency Dependent Fatigue Strength Investigations on Tempered Steel and Nodular Cast Iron JF - steel research international N2 - This paper presents experimental fatigue tests on specially shaped specimens made from quenched and tempered steel 42CrMoS4 and nodular cast iron EN-GJS-600-3. The specimens are geometrically designed to resemble actual subcomponents of forming and cutting dies for sheet metal manufacturing. These subcomponents have failed in the past.Experiments are carried out using a fictive load-time function, which is a modification of an actually measured load curve and has variable mean and amplitude values. This first test series serves as a general validation of a subsequent fatigue analysis. A second test series is carried out with constant mean and amplitude values with a load ratio 𝑅≈0. Here, the load frequencies in the individual test runs are varied between f = 5 Hz and f = 45 Hz in order to investigate the influence of the frequency. Both series are performed on a servo-hydraulic testing machine.The experimental data is then statistically evaluated. The values for the scatter correlate with data from the literature. The data from the test series with the fictive load-time function can thus be used for subsequent validation of a fatigue calculation, which will be addressed in a future publication. Most significant are the findings from the second series of experiments with varied load frequencies, as a significant frequency influence could be detected. Furthermore, the hardening and softening behavior under cyclic loading and the fracture behavior of the materials are analyzed and compared with data from the literature. KW - cast iron KW - fatigue analysis KW - fatigue strength KW - frequency dependence KW - materials testing KW - tempering steel Y1 - 2019 U6 - https://doi.org/10.1002/srin.201800620 VL - 90 IS - 7 PB - Wiley ER - TY - CHAP A1 - Swidergal, Krzysztof A1 - Wagner, Marcus A1 - Lubeseder, Christian A1 - Wurmb, Ingo von A1 - Meinhardt, Josef A1 - Marburg, Steffen T1 - Finite element simulation of blankholder’s lift-off in a deep drawing tool using Abaqus/Standard T2 - SIMULIA Community Conference, 19 - 21 May 2015, Berlin, Germany N2 - In the deep drawing tools for forming car body parts, heavy blankholders are used to prevent buckling and wrinkling of the blank. During each press cycle, those large masses need to be lifted, raising thereby the structural dynamic load on the deep drawing tool and on the press. Therefore a detailed knowledge about the blankholder’s lift-off event is essential for an accurate and robust design of forming tools. In this paper, a dynamic finite element method (FEM) simulation of a blankholder’s lift-off in a selected automotive deep drawing tool is presented enabling identification of regions of critical stresses. The FEM model is built within the Abaqus/CAE environment and solved with Abaqus/Standard. Each dynamic analysis is preceded by a static analysis where the gravity load is applied and the lifting bolts are pre-stressed. A special emphasis is put on modeling the elastomer dampers, which are installed between lifting bolts and the blankholder to avoid hard impacts during the lift-off event. Those dampers are modelled using a hyperelastic material with hysteresis. In addition, an experimental validation of a blankholder’s vibration under operating loading was carried out. The simulation results are in good agreement with the measurements. Y1 - 2015 UR - https://www.semanticscholar.org/paper/Final-Element-Simulation-of-Blankholder-'-s-in-a-%2F-Swidergal-Wagner/8398357757311fc364e3b942cc92c8c0a5f216bc ER - TY - JOUR A1 - Sittl, Christopher A1 - Marburg, Steffen A1 - Wagner, Marcus T1 - Application of a Krylov subspace method for an efficient solution of acoustic transfer functions JF - Mechanical Systems and Signal Processing N2 - Solving acoustic radiation problems, arising from systems including fluid–structure interaction, is of interest in many engineering applications. Computing frequency response functions over a large frequency range is a concern in such applications. A method which solves the Helmholtz equation for multiple frequencies in one step is the matrix-Padé-via-Lanczos connection for unsymmetric systems, as presented by Wagner et al. [1]. The present work is based on Ref. [1] and presents a method for efficiently computing frequency responses over a frequency range for coupled structural-acoustic problems, where the structure and the acoustic near field are discretized with finite elements and an analytical Dirichlet-to-Neumann map approximates the far field. The method is based on a Krylov-subspace projection technique which derives a matrix-valued Padé approximation for a restricted area in the near field and the pressure field on a spherical boundary. On the spherical boundary, where the finite domain is truncated, the non-local modified Dirichlet-to-Neumann operator is applied as a low-rank update matrix. The present contribution extends this method and incorporates new techniques for a more stable model reduction through the Lanczos algorithm and a novel weighted adaptive windowing technique. Further, structural damping is incorporated, for computing the acoustic radiation of a harmonically excited plate. These computed results are compared with acoustic measurements in an anechoic chamber and verified with computational results obtained with a commercial code that uses the perfectly matched layer method. KW - Lanczos algorithm KW - Krylov-subspace projection KW - Dirichlet-to-Neumann map KW - Padé approximation KW - Fluid–structure interaction KW - Acoustics Y1 - 2021 U6 - https://doi.org/10.1016/j.ymssp.2020.107135 VL - 148 PB - Elsevier ER - TY - CHAP A1 - Swidergal, Krzysztof A1 - Lubeseder, Christian A1 - Wurmb, Ingo von A1 - Meinhardt, Josef A1 - Wagner, Marcus A1 - Marburg, Steffen T1 - Vibration analysis of an automotive forming tool using coupled MBS-FEM simulation and experimental validation T2 - Proceedings of the 26th International Conference on Noise and Vibration Engineering (ISMA2014), Leuven, Belgium N2 - To improve efficiency in automotive press shops, press systems with increasingly high stroke rates are beingimplemented, raising thereby the structural dynamic load on the press and especially on the forming tool. Adetailed knowledge of the vibrations and resulting critical loads is thus essential for accurate and reliable de-signs of forming tools. In this paper, multibody simulation (MBS) of a selected automotive tool is presentedenabling the identification of the vibration of its components. Starting from a pure rigid modelling approach,the MBS model is extended by adding finite element (FE) component to allow extra flexibility in the sys-tem. As an example, a detailed vibrational analysis - both in time and frequency domain - is performed ona blankholder. Also an experimental validation of a blankholder vibration under operational load is carriedout, with test signal data gained by piezoelectric accelerometers. Y1 - 2014 UR - http://past.isma-isaac.be/downloads/isma2014/papers/isma2014_0245.pdf SP - 2931 EP - 2942 ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Microrods and microlines by three-dimensional epitaxially grown GaN for field emission cathodes T2 - International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg N2 - The three-dimensional epitaxial technique allows the realization of gallium nitride lines in addition to the rods. To optimize the properties of GaN-based field emission cathodes further investigations and an improvement of the epitaxial process were performed. The microrods and microlines consist of a one-order higher n-doped gallium nitride in comparison to the gallium nitride layer on the sapphire substrate. The typical height of the microrods and -lines is about 5 μm. The field emission properties of these structures were investigated in diode configuration by integral field emission measurements at pressures below 10 -9 mbar. For the microrods (microlines) a voltage of 1100 V (2000 V) was measured for a field emission current of about 0.5 μA with an onset field of about 12 MV/m (24 MV/m). Furthermore, the field enhancement factors for microrods and -lines are in the range of 300 and 200, respectively. KW - field emission KW - GaN KW - LED KW - Gallium nitride KW - Epitaxial growth Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051576 SP - 130 EP - 131 PB - IEEE ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Light emitting diodes based on three-dimensional epitaxial grown crystalline GaN rods T2 - 7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, München Y1 - 2017 SN - 978-3-8007-4491-6 SP - 131 EP - 134 PB - VDE-Verlag CY - München ER - TY - CHAP A1 - Serbun, Pavel A1 - Porshyn, Vitali A1 - Müller, Günter A1 - Lützenkirchen-Hecht, Dirk A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert T1 - Field emission behavior of single n- and p-type black Si pillar structures T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - We have investigated the properties of single n- and p-type black silicon (b-Si) pillars with a height of 20 μ m under strong electric field and halogen lamp or laser illumination. For both type of b-Si pillar structures, I-V measurements revealed strong activation effects, which consisted in sudden current increases during the first up/down voltage sweeps. The maximum reproducible emission current from a single n-type b-Si pillar structure was about 15 μ A. A pronounced saturation region at 240 nA was observed for a single p-type b-Si pillar. The current fluctuation over time showed a standard deviation of 28% and 2.5% for n- and p-type single b-Si pillar structures, respectively. Optical switching under halogen lamp illumination resulted in at least 3 times higher saturation currents and showed a linear dependence of the FE current on the laser power. KW - field emission KW - black silicon KW - photoemission Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520292 PB - IEEE ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Stable and low noise field emission from single p-type Si-tips T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - Single gated p-type Si-tips with two different tip radii were fabricated. An emission current of 2.40 μA was measured for the sharp-edged tip at a voltage of 170 V. In contrast, a stable and reproducible emission behavior was observed with an increased tip radius resulting in a pronounced saturation region between 90 V and 150 V, but merely an emission current of 0.55 μA at 150 V. More remarkable is the stable emission behavior with fluctuation of ± 4 % during a measurement period of 30 minutes. The integral emission current in a homogeneous tip array (16 emitters) showed nearly the same I-V characteristics compared to the single tip and is therefore, most dominated by only a stable single tip in the array. KW - field emission KW - p-type Si-tips KW - gate-electrode KW - emission stability KW - low current fluctuations Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520018 PB - IEEE ER - TY - CHAP A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Sellmair, Josef T1 - Nano Emitters on Silicon Pillar Structures generated by a Focused Electron Beam Induced Deposition T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - Nano emitters were deposited by focused electron beam induced deposition of Trimethyl-(methylcyclopentadienyl)platinum(IV) on top of silicon pillars. The nano emitters were exactly positioned in the center on the top of up to four pillars of a quadratic arranged array of sixteen pillars with a pitch of 50 μm. Integral field emission measurements were performed in a diode configuration with a 50 μm mica spacer in a vacuum chamber at pressures of about 10 -9 mbar. The Fowler-Nordheim plots show a linear behavior, like expected for an n-type silicon material and a metal needle. The I-V measurement of the most promising sample shows an integral emission current up to 2 μm at a voltage of 600 V (12 MV/m) and an onset voltage for a current of 1 nA of about 300 V. KW - field emission KW - nano emitter KW - focused electron beam induced deposition KW - MeCpPtMe3 Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520059 PB - IEEE ER -