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Suche nach „[2020]“ hat 95 Publikationen gefunden
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    NachhaltigEuropan Campus Rottal-InnTC Freyung

    Zeitschriftenartikel

    Javier Valdés, Sebastian Wöllmann, Andreas Weber, G. Klaus, Christina Sigl, M. Prem, Robert Bauer, Roland Zink

    A framework for regional smart energy planning using volunteered geographic information

    Advances in Geosciences, vol. 54, no. 10 December 2020, pp. 179-193

    2020

    DOI: 10.5194/adgeo-54-179-2020

    Abstract anzeigen

    This study presents a framework for regional smart energy planning for the optimal location and sizing of small hybrid systems. By using an optimization model – in combination with weather data – various local energy systems are simulated using the Calliope and PyPSA energy system simulation tools. The optimization and simulation models are fed with GIS data from different volunteered geographic information projects, including OpenStreetMap. These allow automatic allocation of specific demand profiles to diverse OpenStreetMap building categories. Moreover, based on the characteristics of the OpenStreetMap data, a set of possible distributed energy resources, including renewables and fossil-fueled generators, is defined for each building category. The optimization model can be applied for a set of scenarios based on different assumptions on electricity prices and technologies. Moreover, to assess the impact of the scenarios on the current distribution infrastructure, a simulation model of the low- and medium-voltage network is conducted. Finally, to facilitate their dissemination, the results of the simulation are stored in a PostgreSQL database, before they are delivered by a RESTful Laravel Server and displayed in an angular web application.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Jochen Hiller

    Computertomographie (CT) senkt Kosten bei der Retourenbearbeitung

    Sensorik-Magazin des Clusters Sensorik Strategische Partnerschaft Sensorik e.V., vol. 99, no. 4, pp. 3-5

    2020

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    F. Heilmeier, R. Koos, M. Singer, C. Bauer, Peter Hornberger, Jochen Hiller, W. Volk

    Evaluation of Strain Transition Properties between Cast-In Fibre Bragg Gratings and Cast Aluminium during Uniaxial Straining

    Sensors, vol. 20, no. 21

    2020

    DOI: 10.3390/s20216276

    Abstract anzeigen

    Current testing methods are capable of measuring strain near the surface on structural parts, for example by using strain gauges. However, stress peaks often occur within the material and can only be approximated. An alternative strain measurement incorporates fibre-optical strain sensors (Fiber Bragg Gratings, FBG) which are able to determine strains within the material. The principle has already been verified by using embedded FBGs in tensile specimens. The transition area between fibre and aluminium, however, is not yet properly investigated. Therefore, strains in tensile specimens containing FBGs were measured by neutron diffraction in gauge volumes of two different sizes around the Bragg grating. As a result, it is possible to identify and decouple elastic and plastic strains affecting the FBGs and to transfer the findings into a fully descriptive FE-model of the strain transition area.We thus accomplished closing the gap between the external load and internal straining obtained from cast-in FBG and generating valuable information about the mechanisms within the strain transition area.It was found that the porosity within the casting has a significant impact on the stiffness of the tensile specimen, the generation of excess microscopic tensions and thus the formation of permanent plastic strains, which are well recognized by the FBG. The knowledge that FBG as internal strain sensors function just as well as common external strain sensors will now allow for the application of FBG in actual structural parts and measurements under real load conditions. In the future, applications for long-term monitoring of cast parts will also be enabled and are currently under development.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Jochen Hiller, Peter Landstorfer, Philipp Marx, Matthias Herbst

    Evaluation of the impact of faulty scanning trajectories in robot-based x-ray computed tomography

    Measurement Science and Technology, vol. 32, no. 1

    2020

    DOI: 10.1088/1361-6501/abaf2a

    Abstract anzeigen

    X-ray computed tomography (CT) imaging for industrial applications is limited to certain physical conditions to be fulfilled. The size of the measuring object and the accumulated wall thickness are two fundamental conditions. An omission of these conditions by not capturing object attenuation information by the x-ray detector leads to missing data in the 3D reconstruction process and results as a consequence in image degradation and artifacts. Conventional industrial x-ray CT is based on cone-beam projections and circular or helical scanning trajectories using linear axis and a rotary (lift) table. For many inspection tasks on big-sized or unusually shaped objects the physical limits for obtaining a sufficient high image quality are reached very quickly when using conventional CT systems. Industrial six-axis robots offer much more flexibility with respect to the conditions mentioned earlier and can overcome the limitations of conventional scanners. In the present work we characterized an industrial six-axis robot in its working space following ISO 9283 in terms of pose accuracy and pose repeatability. These results are then used to simulate faulty scanning trajectories in terms of pose deviations where a single robot is used as an object manipulator to rotate virtual specimens on a circular trajectory resulting in different (faulty) reconstruction datasets. These datasets are evaluated visually and by using performance parameters and geometrical features in order to determine the reproduction fidelity (performance) of a one arm robot-based CT system depending on different pose errors. With the results obtained it was shown that a robot-based CT system of type B (in our classification scheme) using one robot as object manipulator should be able to reach a spatial resolution power in the range of the voxel size (in our case 200 µm) and smaller (neglecting effects from focal spot size, detector unsharpness from x-ray to light conversation and scatter radiation) if systematic pose errors are compensated using appropriate calibration methods.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    S. Zabler, M. Maisl, Peter Hornberger, Jochen Hiller, C. Fella, R. Hanke

    X-ray imaging and computed tomography for engineering applications

    tm - Technisches Messen, vol. 87, no. Online veröffentlicht: 08.04.2020

    2020

    DOI: 10.1515/teme-2019-0151

    Abstract anzeigen

    After an incremental development which took place over four decades, X-ray imaging has become an important tool for non-destructive testing and evaluation. Computed Tomography (CT) in particular beholds the power of determining the location of flaws and inclusions (e. g. in castings and composites) in three-dimensional object coordinates. Therefore, and thanks to a speed-up of the measurement, CT is now routinely considered for in-line inspection of electronics, castings and composites. When precision and not speed is important, Micro-CT (μCT) can be employed for Dimensional Measurements (DM, e. g. quality assurance and shape verification), as well as for in situ testing, and for characterizing micro-structures in metals and composites. Using appropriate image processing and analysis μCT can determine the local fibre orientation in composites, the granular morphology of battery cathodes or the inter-connectivity of certain phases in casting alloys. Today, the large variety of X-ray instruments and methods poses an application problem which requires experience and a lot of knowledge for deciding which technique applies best to the task at hand. Application-specific guidelines exist for X-ray radiography testing (RT) only, whereas standardization has been applied to CT, unfortunately leaving out high resolution subμ CT, and nano-CT. For the latter exist an equally high number of NDT applications, however these instruments still necessitate a profound expertise. The task is to identify key industrial applications and push CT from system standardization to application specific automation.

    DigitalTC Grafenau

    Zeitschriftenartikel

    Ali Fallah-Tehrani

    The Choquet Kernel on the use of Regression Problem

    Information Sciences, no. 08 December 2020

    2020

    DOI: 10.1016/j.ins.2020.11.051

    Abstract anzeigen

    Recently, we have presented a new family of kernels on the basis of the discrete Choquet integral. While a naïve computation of this kernel has an exponential complexity in the number of features, we have proposed an efficient approach with computational complexity of 1. This kernel family is able to recognize dependencies between features and moreover it can be regularized through a proper selection of q-additivity. In fact, to reduce the effect of over-fitting there is an opportunity to restrict the flexibility of kernel to a lower degree. A key feature of the Choquet integral in a data-driven way is its monotonicity, however, this representation does not consider any monotonicity constraint; hence it is versatile for other applications, too. This issue is highlighted in the experimental study. In this regard, we apply the Choquet kernel for regression task and compare the performance of the proposed kernel versus state-of-the-art support kernel-based regression methods as well as random forest.

    DigitalNachhaltigEuropan Campus Rottal-Inn

    Zeitschriftenartikel

    Kueppers. M., C. Perau, M. Franken, H. Heger, Matthias Huber, M. Metzger, S. Niessen

    Data-Driven Regionalization of Decarbonized Energy Systems for Reflecting Their Changing Topologies in Planning and Optimization

    Energies, vol. 13, no. 16

    2020

    DOI: 10.3390/en13164076

    Abstract anzeigen

    The decarbonization of energy systems has led to a fundamental change in their topology since generation is shifted to locations with favorable renewable conditions. In planning, this change is reflected by applying optimization models to regions within a country to optimize the distribution of generation units and to evaluate the resulting impact on the grid topology. This paper proposes a globally applicable framework to find a suitable regionalization for energy system models with a data-driven approach. Based on a global, spatially resolved database of demand, generation, and renewable profiles, hierarchical clustering with fine-tuning is performed. This regionalization approach is applied by modeling the resulting regions in an optimization model including a synthesized grid. In an exemplary case study, South Africa’s energy system is examined. The results show that the data-driven regionalization is beneficial compared to the common approach of using political regions. Furthermore, the results of a modeled 80% decarbonization until 2045 demonstrate that the integration of renewable energy sources fundamentally changes the role of regions within South Africa’s energy system. Thereby, the electricity exchange between regions is also impacted, leading to a different grid topology. Using clustered regions improves the understanding and analysis of regional transformations in the decarbonization process.

    NachhaltigTSZ Weißenburg

    Zeitschriftenartikel

    Y.A.O. Assagra, Altafim, R.A.P., J. do Carmo, R.A.C. Altafim, Dmitry Rychkov, Wirges, W., Gerhard, R.

    A new route to piezo-polymer transducers: 3D printing of polypropylene ferroelectrets

    IEEE Transactions on Dielectrics and Electrical Insulation, vol. 27, no. 5, pp. 1668-1674

    2020

    DOI: 10.1109/TDEI.2020.008461

    Abstract anzeigen

    Here, a promising approach for producing piezo-polymer transducers in a one-step process is presented. Using 3D-printing technology and polypropylene (PP) filaments, we are able to print a two-layered film structure with regular cavities of precisely controlled size and shape. It is found that the 3D-printed samples exhibit piezoelectric coefficients up to 200 pC/N, similar to those of other PP ferroelectrets, and their temporal and thermal behavior is in good agreement with those known of PP ferroelectrets. The piezoelectric response strongly decreases for applied pressures above 20 kPa, as the pressure in the air-filled cavities strongly influences the overall elastic modulus of ferroelectrets.

    DigitalAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Buch (Monographie)

    Franz Xaver Röhrl

    Ein flexibles Leiterplatten-Technologiekonzept für Anwendungen im Millimeterwellenbereich

    Dissertationsschrift

    Elektrotechnik, München

    2020

    ISBN: 978-3-8439-4537-0

    Abstract anzeigen

    Die vorliegende Arbeit beschreibt ein Konzept zum Betrieb von millimeterwellentauglichen Schaltungen auf konventionellen Leiterplatten. Dazu werden neben den technologischen Grundlagen und neuen Leiterplattentechnologien auch konkrete Realisierungen von Schaltungen vorgestellt. Der Fokus liegt dabei auf einer toleranzarmen, fertigungstechnisch prozesssicheren Umsetzung. Die entwickelten Fertigungsverfahren und Optimierungen erlauben die Herstellung von bisher nicht realisierbaren Feinstleiter-Strukturen auf Außenlagen und ermöglichen dadurch auch eine breitbandige dämpfungsarme Signalführung. Ein großer Vorteil der hier vorgestellten Umsetzung ist, dass die Verfahren zum Großteil mit konventionellen Leiterplattenprozessen umgesetzt werden können und auch eine beliebige Kombination mit bestehenden Leiterplattenprozessen zulässig ist. Es wird versucht möglichst viele Funktionen und Herausforderungen direkt auf der kostengünstigen Leiterplatte zu lösen. Das Konzept beinhaltet zudem eine breite Auswahl an Möglichkeiten zur reflexionsarmen Kontaktierung der Leiterplatte von Signalen im Millimeterwellenbereich. Außerdem wird die Anbindung von aktiven Bausteinen und anderen Schaltungsträgern detailliert behandelt. Die Ergebnisse werden sowohl mit dem aktuellen Stand der Leiterplattentechnologie als auch mit alternativen Fertigungstechnologien verglichen und bewertet.

    DigitalAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Zeitschriftenartikel

    Felix Sepaintner, Andreas Scharl, Franz Xaver Röhrl, Werner Bogner, Stefan Zorn

    Characterization and Production of PCB Structures With Increased Ratio of Electromagnetic Field in Air

    IEEE Transactions on Microwave Theory and Techniques, vol. 68, no. 6, pp. 2134-2143

    2020

    DOI: 10.1109/TMTT.2020.2983934

    Abstract anzeigen

    Producing passive printed circuit board (PCB) structures in the millimeter-wave range includes some fundamental challenges, such as low manufacturing costs and high fabrication accuracy. These aspects, in general, have to be combined with low signal attenuation, precise simulation models, and a reliable producibility. This article shows a new method to manufacture different kinds of passive RF waveguides with reduced attenuation and decreased electrical length on low-cost PCB substrates. First, the complex material parameters of the used substrate and the used copper foil are extracted from 10 to 100 GHz to have accurate simulation models in CST Microwave Studio. This is necessary because the parameters provided by the manufacturer are often no longer generally valid in this frequency range. In addition, PCB materials have a significantly higher surface roughness compared with conventional materials for millimeter-wave applications. Therefore, the correct determination and the correct modeling of surface roughness is particularly important. Next, laminate is removed partially on the outer layer of the PCB to increase the electromagnetic field ratio in air. The undesired substrate is removed by a CO2 laser drilling machine by setting narrow drills sequentially. The RF performance of these waveguides is compared with those manufactured in conventional PCB technology according to attenuation and producibility.

    DigitalAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Zeitschriftenartikel

    E. Hassan, B. Scheiner, F. Michler, M. Berggren, E. Wadbro, Franz Xaver Röhrl, Stefan Zorn, R. Weigel, F. Lurz

    Multi-Layer Topology Optimization of Wideband SIW-to-Waveguide Transitions

    IEEE Transactions on Microwave Theory and Techniques, vol. 68, no. 4, pp. 1326-1339

    2020

    DOI: 10.1109/TMTT.2019.2959759

    Abstract anzeigen

    This article utilizes a topology optimization approach to design planar multilayer transitions between substrate integrated waveguides (SIWs) and rectangular waveguides (RWGs). The optimization problem is formulated based on the modal field analyses and Maxwell's equations in the time domain solved by the finite-difference time-domain (FDTD) method. We present a time-domain boundary condition based on the Klein-Gordon equation to split traveling waves at homogeneous waveguide ports. We employ the boundary condition to compute portal quantities and to devise an adjoint-field system that enabled an efficient computation of the objective function gradient. We solve design problems that include more than 105 000 design variables by using less than 400 solutions of Maxwell's equations. Moreover, a new formulation that effectively combats the development of in-band resonances in the design is presented. The transition configuration allows the direct mount of conventional RWG sections on the circuit board and aims to cover the entire K-band. The guiding structure of the optimized transition requires blind vias, which is realized by a simple and cost-efficient technique. In addition, the transition is optimized for three different setups that can be used to provide different field polarizations. The proposed transitions show less than 1-dB insertion loss and around 15-dB return loss over the frequency interval 18-28 GHz. Several prototypes are fabricated with an excellent match between the simulation and measurement results.

    DigitalDEG-DLM2Zentrum für Akademische Weiterbildung

    Buch (Monographie)

    Caroline Weber

    Ein Review zum empfohlenen Einsatz von automatisierten Vorlesungsaufzeichnungen an Hochschulen.

    2020

    DigitalDEG-DLM2Zentrum für Akademische Weiterbildung

    Buch (Monographie)

    Caroline Weber

    Automatisierte Vorlesungsaufzeichnungen im Projekt DEG-DLM2 – Evaluation der Einsatzerfahrungen

    2020

    DigitalDEG-DLM2Zentrum für Akademische Weiterbildung

    Buch (Monographie)

    Projekt DEG-DLM2

    Verwertungskonzept für das Projekt DEG-DLM2

    2020

    DigitalDEG-DLM2Zentrum für Akademische Weiterbildung

    Buch (Monographie)

    Benjamin Nädele

    Qualitative Analyse von Webkonferenzen im Projekt DEG-DLM2

    2020

    DigitalDEG-DLM2Zentrum für Akademische Weiterbildung

    Buch (Monographie)

    Benjamin Nädele

    Qualitative Analyse von Webkonferenzen im Projekt DEG-DLM1

    2020

    DigitalDEG-DLM2Zentrum für Akademische Weiterbildung

    Buch (Monographie)

    Karina Fisch, Sabrina Ebner

    Nutzungskonzept für die Erkenntnisse aus dem Projekt DEG-DLM2

    2020

    DigitalDEG-DLM2Zentrum für Akademische Weiterbildung

    Buch (Monographie)

    Christian Ebner

    Webkonferenzen im Projekt DEG-DLM2 – Begleitforschung zum Einsatz der im Vergleich zur ersten Förderphase optimierten digitalen Lehrmodalität

    2020

    DigitalDEG-DLM2Zentrum für Akademische Weiterbildung

    Buch (Monographie)

    Christian Ebner

    Bericht Begleitforschung Modul „Wissenschaftliches Arbeiten“ der Studiengänge Pflegepädagogik und Pädagogik im Rettungswesen

    2020