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IEEE Open Journal of Vehicular Technology 2025年

作者： Tao, Qin Li, Zhongjie Zhi, Kangda Li, Shuangyang Yuan, Weijie Zaniboni, Lorenzo Stanczak, Slawomir Viterbo, Emanuele Wang, Xianbin Hangzhou Normal University School of Information Science and Technology Hangzhou311121 China School of Automation and Intelligent Manufacturing Southern University of Science and Techonology Shenzhen518055 China Technical University of Berlin School of Electrical Engineering and Computer Science Berlin10623 Germany Technical University of Munich Institute for Communications Engineering Munich80333 Germany Fraunhofer Heinrich Hertz Institute Wireless Communications and Networks Department Berlin10587 Germany Monash University Department of Electrical and Computer Systems Engineering ClaytonVIC3800 Australia Western University Department of Electrical and Computer Engineering LondonONN6A 5B9 Canada

The vision for 6th-generation (6G) wireless communication systems emphasizes the need for robust and reliable communication in extremely high-mobility scenarios, while also addressing critical demands for energy and spectral efficiency. Under such scenarios, doubly time-frequency selective fading channels often significantly degrade the performance of orthogonal frequency-division multiplexing (OFDM) based systems due to the impact of large delay and Doppler shifts. Recently, orthogonal time frequency space (OTFS) modulation has emerged as a promising alternative. By processing signals in the delay-Doppler (DD) domain, OTFS offers several advantages, including quasi-static channel characteristics, full-time-frequency diversity, and low peak-to-average power ratio (PAPR), making it a promising candidate for high-mobility communications. Reconfigurable intelligent surfaces (RIS) are being further integrated to enhance the performance of OTFS systems cost-effectively. With their ability to dynamically reconfigure the wireless environment, the integration of RIS can offer significant performance improvements for OTFS systems. This survey offers a comprehensive review of RIS-assisted OTFS systems, including the fundamental principles, recent advances, and future research directions. Specifically, we first introduce the background of RIS-assisted OTFS systems, outlining the opportunities and challenges of their integration. To ensure the survey is self-contained, we provide a brief overview of the fundamental principles of OTFS and RIS technologies. Building on these foundations, we present a general input-output relationship and capacity characterization for RIS-assited MIMO-OTFS systems. Then, this survey further explores cutting-edge research in areas such as input-output analysis, RIS phase shift design, channel estimation, detection techniques, RIS-assisted integrated sensing and communication (ISAC), and other novel technologies. Finally, we outline some future rese

关键词： Orthogonal frequency division multiplexing

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Temperature Characterization of High-Q Resonators of Different Materials for mm-Wave Indoor Localization Tag Landmarks

Temperature Characterization of High-Q Resonators of Differe...

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European Conference on Antennas and Propagation, EuCAP

作者： Alejandro Jiménez-Sáez Martin Schüßler Damian Pandel Christopher Krause Yixiong Zhao Gerd vom Bögel Niels Benson Rolf Jakoby Institute of Microwave Engineering and Photonics Technische Universität Darmstadt Darmstadt Germany Institute of Technology for Nanostructures and CENIDE University of Duisburg-Essen Duisburg Germany Fraunhofer Institute for Microelectronic Circuits and Systems Duisburg Germany

ISBN: (数字)9788831299008

ISBN: (纸本)9781728137124

This paper discusses a temperature-dependent characterization of deep reactive ion-etched 10 kΩ cm high-resistive silicon (DRIE HR-Si), 3D printed alumina (Al 2 O 3 ) and milled Rogers RT/Duroid ® 6010.2LM. The characterization is performed by measuring high-Q photonic crystal resonator samples in W-band and the measurements are taken from 30 °C to 115 °C. HR-Si is the material with the lowest losses at room temperature. However, its losses increase with temperature and become higher than 3D printed alumina at 75 °C, reducing the radar cross-section and maximum readout range of chipless wireless RFID tags integrating several of these resonators. These results demonstrate that, while HR-Si performance is higher for the usual temperatures achieved in an indoor localization scenario, 3D printed alumina is more suitable if a temperature-stable response is needed or if the tags need to operate at high temperatures, such as in case of fire.

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Modeling energy and resource use in additive manufacturing of automotive series parts with multi-jet fusion and selective laser sintering

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Procedia CIRP 2021年 98卷 358-363页

作者： Mathias Wiese Alexander Leiden Christopher Rogall Sebastian Thiede Christoph Herrmann Polymer Additive Manufacturing Center AUDI AG Auto-Union-Straβe 1 Ingolstadt 85045 Germany Chair of Sustainable Manufacturing and Life Cycle Engineering Institute of Machine Tools and Production Technology Technische Universität Braunschweig Langer Kamp 19b Braunschweig 38106 Germany Chair of Manufacturing Systems Department Design Production and Management University of Twente Drienerlolaan 5 Enschede 7522NB The Netherlands Fraunhofer Institute for Surface Engineering and Thin Films (1ST) Bienroder Weg 54 E Braunschweig 38108 Germany

With additive manufacturing (AM) becoming a competitive manufacturing process for low to medium production volumes, rapid manufacturing becomes an increasingly relevant manufacturing approach. However, regulations and customers demand more eco-efficient life-cycles of products. This requires engineers and designers to pre-select between productive AM processes like selective laser sintering (SLS) and multi-jet fusion (MJF), based on their expected environmental impact in series production. As SLS already debuted in the mid-1980s, researches broadly explored parts’ mechanical properties, energy and resource use. The multi-jet fusion (MJF) technology, introduced in 2017, delivers comparable part properties at considerably higher print speeds. However, its energy and resource use is still scarcely covered. To close this gap, this publication develops a model for evaluation of energy and resource utilization based on a case study with an automotive exterior series part using an EOS P396 SLS and a HP 4200 MJF machine. Data from measurements in energy and material consumption as well as the print job shows a good predictability and builds the basis for an environmental assessment. The derived model and its functional blocks allow estimation and comparison of sustainability for different use cases in rapid manufacturing with MJF and SLS. Despite the process similarities, results concerning greenhouse gas emissions and cumulative energy demand are different. The gained insights enhance pre-selection of manufacturing strategies, a suitable printing technology and the evaluation of AM processes during manufacturing according to sustainability aspects. Printer manufacturers and users may find this research insightful for improvements in sustainability and comparability of future AM processes.

关键词： Rapid manufacturing Energy efficiency Resource efficiency Additive manufacturing Automotive engineering Process modeling

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Carrier-envelope offset stable, coherently combined ytterbium-doped fiber CPA delivering 1 kW of average power

arXiv

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arXiv 2022年

作者： Shestaev, E. Hädrich, S. Walther, N. Eidam, T. Klenke, Arno Seres, I. Bengery, Z. Jójárt, P. Várallyay, Z. Börzsönyi, Á. Limpert, J. Active Fiber Systems GmbH Ernst-Ruska-Ring 17 Jena07745 Germany Friedrich-Schiller-Universität Jena Abbe Center of Photonics Institute of Applied Physics Albert-Einstein-Straße 15 Jena07745 Germany Helmholtz-Institute Jena Fröbelstieg 3 Jena07743 Germany ELI-ALPS ELI-HU Non-Profit Ltd. Wolfgang Sandner utca 3. SzegedH-6728 Hungary Fraunhofer Institute for Applied Optics and Precision Engineering IOF Albert-Einstein-Straße 7 Jena07745 Germany

We present a carrier-envelope offset (CEO) stable ytterbium-doped fiber chirped-pulse amplification system employing the technology of coherent beam combining and delivering more than 1 kW of average power at a pulse repetition rate of 80 MHz. The CEO stability of the system is 220 mrad rms, characterized out-of-loop with an f-to-2f interferometer in a frequency offset range of 10 Hz to 20 MHz. The high power amplification system boosts the average power of the CEO stable oscillator by five orders of magnitude, while increasing the phase noise by only 100 mrad. No evidence of the CEO noise deterioration due to coherent beam combining has been found. Low-frequency CEO fluctuations at the CPA are suppressed by a "slow loop" feedback. This is the first demonstration of a coherently combined laser system delivering an outstanding average power and a high CEO stability at the same time. Copyright © 2022, The Authors. All rights reserved.

关键词： Pulse repetition rate

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4-channel coherently combined long-term-stable ultrafast thulium-doped fiber CPA

4-channel coherently combined long-term-stable ultrafast thu...

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Advanced Solid State Lasers, ASSL 2020 - Part of Laser Congress, LAC 2020

作者： Gaida, Christian Stutzki, Fabian Gebhardt, Martin Heuermann, Tobias Breitkopf, Sven Eidam, Tino Rothhardt, Jan Limpert, Jens Active Fiber Systems GmbH Ernst-Ruska-Ring 17 Jena07745 Germany Institute of Applied Physics Abbe Center of Photonics Friedrich-Schiller-Universität Jena Albert-Einstein-Str. 15 Jena07745 Germany Helmholtz-Institute Jena Fröbelstieg 3 Jena07743 Germany Fraunhofer Institute for Applied Optics and Precision Engineering Albert-Einstein-Str. 7 Jena07745 Germany

ISBN: (纸本)9781557528209

We present the first coherently combined, thulium-doped fiber CPA delivering >100 W average-power and simultaneously >1 GW of peak-power. Incorporating four amplifier channels the laser delivers pulses with >228 µJ energy and 48 hours - ideal prerequisites for next-generation industrial and scientific applications. © 2020 The Author(s)

关键词： Thulium

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Soft x-ray high order harmonic generation from high power ultrafast thulium-doped fiber lasers

Soft x-ray high order harmonic generation from high power ul...

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2020 Compact EUV and X-ray Light Sources, EUVXRAY 2020 - Part of OSA High-Brightness Sources and Light-Driven Interactions Congress 2020

作者： Gebhardt, M. Heuermann, T. Gaida, C. Wang, Z. Lenski, M. Klas, R. Kirsche, A. Liu, C. Hädrich, S. Jauregui, C. Rothhardt, J. Limpert, J. Institute of Applied Physics Abbe Center of Photonics Friedrich-Schiller-Universität Jena Albert-Einstein-Str. 15 Jena07745 Germany Helmholtz-Institute Jena Fröbelstieg 3 Jena07743 Germany Active Fiber Systems GmbH Ernst-Ruska-Ring 11 Jena07745 Germany Fraunhofer Institute for Applied Optics and Precision Engineering Albert-Einstein-Str. 7 Jena07745 Germany

We report on soft x-ray HHG driven by a thulium-doped fiber laser. It is the first time that a photon energy cut-off ∼400 eV has been demonstrated using this highly scalable laser technology. © 2020 OSA - The Op... 详细信息

ISBN: (纸本)9781943580736

关键词： Fiber lasers

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Adaptive folding and noise filtering for robust quantum error mitigation

arXiv

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arXiv 2025年

作者： Koenig, Kathrin F. Reinecke, Finn Wellens, Thomas Fraunhofer Institute for Applied Solid State Physics Tullastr. 72 Freiburg79108 Germany Department of Sustainable Systems Engineering University of Freiburg Emmy-Noether-Str. 2 Freiburg79110 Germany Department of Computer Science University of Freiburg Georges-Köhler-Allee 51 Freiburg79110 Germany

Coping with noise in quantum computation poses significant challenges due to its unpredictable nature and the complexities of accurate modeling. This paper presents noise-adaptive folding, a technique that enhances zero-noise extrapolation (ZNE) through the use of adaptive scaling factors based on circuit error measurements. Furthermore, we introduce two filtering methods: one relies on measuring error strength, while the other utilizes statistical filtering to improve the extrapolation process. Comparing our approach with standard ZNE reveals that adaptive scaling factors can be optimized using either a noise model or direct error strength measurements from inverted circuits. The integration of adaptive scaling with filtering techniques leads to notable improvements in expectation-value extrapolation over standard ZNE. Our findings demonstrate that these adaptive methods effectively strengthen error mitigation against noise fluctuations, thereby enhancing the precision and reliability of quantum computations. © 2025, CC BY.

关键词： Qubits

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CBED Investigations of Mesoscopic Semiconductor Structures

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Microscopy and Microanalysis 2020年第S2期5卷 208-209页

作者： H. Lakner F. Schulze-Kraasch C. Mendorf G. Brockt Fraunhofer-Institute for Microelectronic Circuits and Systems Grenzstrasse 28 D-01109 Dresden Germany University of Duisburg Materials for Electrical Engineering WET/FB9 Bismarckstrasse 81 D-47048 Duisburg Germany

Ternary and quaternary heterostructures from III-V-semiconductors get more and more importance in the fabrication of high-speed/high frequency devices in telecommunication systems. One of the key parameters for the performance of such devices is the crystalline quality and especially the amount of tetragonal distortion in strained layers on a nanometer scale. Strain can cause problems for the growth of such layers like relaxation induced defects, especially for the case of a high value of lattice mismatch. However, strain and the associated influence on the band structure can be used consciously for the design of tailor-made heterostructures (band gap engineering). Therefore, the spatially resolved investigation of local crystal properties (tetragonal distortion or strain and strain relaxation) is a key tool for the characterization of strained *** beam electron diffraction (CBED) patterns and convergent beam imaging (CBIM) can be used to evaluate informations on the local crystalline structure. E.g. the position of the High Order Laue Zone (HOLZ) lines in the CBED patterns is sensitive to the local strain and therefore can be used to determine strain and relaxation effects in heterostructures quantitatively. But in practice the applicability of CBED is often limited by a lack of ultimate spatial resolution and/or of sensitivity.

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ENHANCING TRUST IN INTER-ORGANISATIONAL DATA SHARING: LEVELS OF ASSURANCE FOR DATA TRUSTWORTHINESS

arXiv

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arXiv 2025年

作者： Zimmer, Florian Haber, Janosch Kaneko, Mayuko Fraunhofer Institute for Software and Systems Engineering ISST Speicherstraße 6 Dortmund44147 Germany Fujitsu Research of Europe 9 Albert St SloughSL1 2BE United Kingdom Fujitsu Limited 4-1-1 Kamikodanaka Nakahara-ku Kanagawa Kawasaki211-8588 Japan

As data is increasingly acknowledged as a highly valuable asset, much effort has been put into investigating inter-organisational data sharing, aiming at utilising the value of formerly unused data. Moreover, most researchers agree, that trust between actors is key for successful data sharing activities. However, existing research oftentimes focus on trust from a data provider perspective. Therefore, our work highlights the unbalanced view of trust, addressing it from a data consumer perspective. More specifically, our aim is to investigate trust enhancing measures on a data level, that is data trustworthiness. We found, that existing data trustworthiness enhancing solutions do not meet the requirements of the domain of inter-organisational data sharing. Therefore, our study addresses this gap. Conducting a rigorous design science research approach, this work proposes a new Levels of Assurance for Data Trustworthiness artifact. Built on existing artifacts, we demonstrate, how it addresses the identified challenges within the domain appropriately. We found that our novel approach requires more work to be suitable for adoption. Still, we are confident that our solution can increase consumer trust. We conclude by contributing to the body of design knowledge and emphasise the need for more attention to be put into consumer trust. Copyright © 2025, The Authors. All rights reserved.

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Agent-based simulation for production planning and control in consideration of disruption events 49

Agent-based simulation for production planning and control i...

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49th International Conference on Computers and Industrial engineering, CIE 2019

作者： Bui, M.D. Nguyen, Q.H. Kohl, H. Institute for Machine Tools and Factory Management Technical University of Berlin Germany Faculty of Engineering Vietnamese-German University Viet Nam Institute for Production Systems and Design Technology Fraunhofer-Gesellschaft Berlin Germany

An agent-based simulation (ABS) as a computer supported decision-making tool is presented for planning and evaluating job shop production. The presented approach focuses on short-term production planning and control. It allows planners to design and modify their models by describing all activities of workers and machines regarding operations related to the manufacturing process and tasks aided in the production. The simulated model was used for analyzing different operation modes and control strategies dealing with disruption events including machine breakdown, worker absence, and product defect. This provides an easy-to-implement simulation result through a description of coordinated actions and interactions of system resources. A case study for a remanufacturing job-shop shows effects of disruption events and reaction plans on the system performances. © 2019, Computers and Industrial engineering. All rights reserved.

关键词： Planning

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