13 research outputs found

    Konzeptionierung und Implementierung einer hybriden MAC-Layer-Architektur fĂĽr Paket-basierte Powerline Kommunikation auf einem FPGA

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    [no abstract available

    Entwicklung und Optimierung von Software fĂĽr eine mikrocontrollerbasierte Steuerung einer Messeinheit mit High-Speed USB-Schnittstelle

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    [no abstract available

    Optimized Minimum-Search for SAR Backprojection Autofocus on GPUs Using CUDA

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    Autofocus techniques for synthetic aperture radar (SAR) can improve the image quality substantially. Their high computational complexity imposes a challenge when employing them in runtime-critical implementations. This paper presents an autofocus implementation for stripmap SAR specially optimized for parallel architectures like GPUs. Thorough evaluation using real SAR data shows that the tunable parameters of the algorithm allow to counterbalance runtime and achieved image quality.© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

    Measuring vertical jump height using a smartphone camera with simultaneous gravity-based calibration

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    Vertical jump height is an important tool to measure athletes' lower body power in sports science and medicine. Several different methods exist to measure jump height, but each has its own limitations. This work proposes a novel way to measure jump height directly, using optical tracking with a single smartphone camera. A parabolic fall trajectory is obtained from this video by tracking a single feature. The parabolic trajectory is then used to partially calibrate the camera and convert pixel measurements into real-world units, allowing the calculation of the achieved height. Comparison to an optical motion capture system yields promising results.© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

    A Case Study on Multi-Softcore Aided Hardware Architectures for Powerline MAC-Layer

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    Powerline communication is a promising technology for connecting Internet of Things (IoT) applications, where devices have strict limitations regarding available installation space and power dissipation. Especially the wiring of these devices benefits from not having additional cables for network connection. Thus, saving costs and additional installation effort. In this paper a very resource-efficient implementation of a HomePlug 1.0.1 [5] compatible powerline MAC layer, which is used to control the data flow and link status of a powerline connection, is presented. The MAC layer is implemented in two variants, using state machines and softcore processors. A comparison of the two approaches shows that the softcore design used up to 78 % less FPGA ressources and is superior in terms of flexibility and maintainability

    Synthetic Aperture Radar Algorithms on Transport Triggered Architecture Processors using OpenCL

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    Live SAR imaging from small UAVs is an emerging field. On-board processing of the radar data requires high-performance and energy-efficient platforms. One candidate for this are Transport Triggered Architecture (TTA) processors. We implement Backprojection and Backprojection Autofocus on a TTA processor specially adapted for this task using OpenCL. The resulting implementation is compared to other platforms in terms of energy efficiency. We find that the TTA is on-par with embedded GPUs and surpasses other OpenCL-based platforms. It is outperformed only by a dedicated FPGA implementation. © 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

    Dynamical mean-field theory of indirect magnetic exchange

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    To analyze the physical properties arising from indirect magnetic exchange between several magnetic adatoms and between complex magnetic nanostructures on metallic surfaces, the real-space extension of dynamical mean-field theory (R-DMFT) appears attractive as it can be applied to systems of almost arbitrary geometry and complexity. While R-DMFT describes the Kondo effect of a single adatom exactly, indirect magnetic (RKKY) exchange is taken into account on an approximate level only. Here, we consider a simplified model system consisting of two magnetic Hubbard sites ("adatoms") hybridizing with a non-interacting tight-binding chain ("substrate surface"). This two-impurity Anderson model incorporates the competition between the Kondo effect and indirect exchange but is amenable to an exact numerical solution via the density-matrix renormalization group (DMRG). The particle-hole symmetric model at half-filling and zero temperature is used to benchmark R-DMFT results for the magnetic coupling between the two adatoms and for the magnetic properties induced in the substrate. In particular, the dependence of the local adatom and the nonlocal adatom-adatom static susceptibilities as well as the magnetic response of the substrate on the distance between the adatoms and on the strength of their coupling with the substrate is studied. We find both, excellent agreement with the DMRG data even on subtle details of the competition between RKKY exchange and the Kondo effect but also complete failure of the R-DMFT, depending on the parameter regime considered. R-DMFT calculations are performed using the Lanczos method as impurity solver. With the real-space extension of the two-site DMFT, we also benchmark a simplified R-DMFT variant.Comment: 14 pages, 8 figure

    Implementing Synthetic Aperture Radar Backprojection in Chisel – A Field Report

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    Chisel is an emerging hardware description language which is especially popular in the RISC-V community. In this report, we evaluate its application in the field of general digital hardware design. A dedicated hardware implementation of a Synthetic Aperture Radar (SAR) processing algorithm is used as an example case for a real-world application. It is targeting a modern high performance FPGA platform. We analyze the difference in code size compared to a VHDL implementation. In contrast to related publications, we classify the code lines into several categories, providing a more detailed view. Overall, the number of lines was reduced by 74% while the amount of boilerplate code was reduced by 83%. Additionally, we report on our experience using Chisel in this practical application. We found the generative concept and the flexibility introduced by modern software paradigms superior to traditional hardware description languages. This increased productivity, especially during timing closure. However, additional programming skills not associated with classic hardware design are required to fully leverage its advantages. We recommend Chisel as a language for all hardware design tasks and expect its popularity to increase in the future

    Powerline Communication System-on-Chip in 180 nm Harsh Environment SOI Technology

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    Broadband powerline communication systems using Orthogonal Frequency Division Multiplexing (OFDM) can utilize existing power lines to transmit data packets alongside power distribution. Recent standards focus towards high speed multi-media in-house streaming. With improvements towards robustness and throughput new standards increase the speed and reliability of in-house powerline systems. A very different approach is the use of powerline communication systems in a deep drilling environment where temperatures of more than 150°C and pressure levels up to 30 000 psi are present. Typical applications in this environment usually do not require more than several kbit/ys per node and are more reliant on a stable and continuous connection. Here, a powerline communication system can reduce the amount of wiring needed and increase communication robustness significantly. This work provides a harsh environment suitable, reliable and standard compliant communication ASIC that is manufactured in XFAB 180 nm Silicon-On-Insulator (SOI) technology allowing operating temperatures of up to 175°C. The die size is 5.25 mm x 5.25 mm and contains a complete Homeplug 1.0 communication stack with an environment for boot, interfacing and debugging. The data rate is as high as 6.1 Mbit/s using the fastest transmission mode and reaches the theoretical maximum of 0.55 Mbit/s in the robust OFDM (ROBO) mode which is of particular interest for harsh environment applications. To the best of the authors knowledge, this is the first OFDM-based powerline communication ASIC which is particularly designed for harsh environment.© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

    Verwendung von Intertialsensoren zur automatisierten Auswertung sensomotorischer Tests

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    Um die sensomotorische Leistungsfähigkeit von Sportlern zu evaluieren, gibt es verschiedene sportwissenschaftliche Standardtests, wie zum Beispiel den Y-Balance-Test (YBT). Allerdings ist bei vielen dieser Verfahren ein Tester nötig, der die Durchführung leitet und das Ergebnis bestimmt. In dieser Arbeit wird der Ansatz für ein System auf Basis von Inertialsensoren (IMUs) vorgestellt, durch das die Auswertung verschiedener im Bereich der Sportwissenschaften gängiger Tests automatisiert werden kann. Implementiert wurde der YBT und die aktive Winkelreproduktion. Durch die Automatisierung muss während des Tests kein Tester mehr anwesend sein, wodurch beispielsweise Freizeitsportler, Leistungssportler, Trainer, Vereine, aber auch Forschungseinrichtungen in die Lage versetzt werden, diese Tests jederzeit durchzuführen. Durch die Verwendung von IMUs, die ihre eigene Ausrichtung als Quaternion schätzen, wird im vorgestellten System die aktuelle Pose der Knochen im Skelett des Nutzers berechnet. Aus diesen werden dann die verschiedenen Testergebnisse, wie Gelenkwinkel oder die Position einzelner Extremitäten, bestimmt. Als Plattform kommt ein mobiles Gerät zum Einsatz, auf dem die Berechnung und die Visualisierung in Echtzeit erfolgen
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