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Bifocal technique applied to dual transmitarray antennas 12

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Bifocal technique applied to dual transmitarray antennas

12th European Conference on Antennas and Propagation, EuCAP 2018

作者： Martinez-De-Rioja, Eduardo Encinar, José A. Pino, Antonio Gonzalez-Valdes, Borja Hum, Sean V. Tienda, Carolina Toso, Giovanni Information Processing and Telecomm. Center Universidad Politécnica de Madrid Spain Department of Signal Theory and Communications Universidad de Vigo Spain Dept. of Electrical and Computer Engineering University of Toronto Canada Antenna Group Airbus Defence and Space Stevenage United Kingdom Electromagnetics Division European Space Agency Noordwijk Netherlands

ISBN: (纸本)9781785617911

The bifocal technique has been applied to dual transmitarray antennas in order to improve the performance of multi-beam satellite antennas in Ka-band. The use of a transmitarray design allows centered and rotationally symmetrical geometries to be used without blockage. Different dual transmitarray configurations have been studied for operation in transmission in Ka-band (20 GHz), and the bifocal technique has been evaluated for the generation of closely-spaced beams. The results of the simulations show that it is possible to achieve a high degree of beam compression, but at the cost of a reduction in the antenna radiation efficiency. © Institution of engineering and *** Rights Reserved.

关键词： Satellite antennas

Neural signatures of motor skill in the resting brain

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arXiv 2019年

作者： Özdenizci, Ozan Meyer, Timm Wichmann, Felix Peters, Jan Schölkopf, Bernhard Çetin, Müjdat Grosse-Wentrup, Moritz Department of Electrical and Computer Engineering Northeastern University BostonMA United States Signal Processing and Information Systems Laboratory Faculty of Engineering and Natural Sciences Sabancı University Istanbul Turkey Max Planck Institute for Intelligent Systems Tübingen Germany Faculty of Science University of Tübingen Bernstein Center for Computational Neuroscience Tübingen Tübingen Germany FG Intelligente Autonome Systeme Technische Universität Darmstadt Darmstadt Germany Department of Electrical and Computer Engineering University of Rochester RochesterNY United States Research Group Neuroinformatics Faculty of Computer Science University of Vienna Vienna Austria

Stroke-induced disturbances of large-scale cortical networks are known to be associated with the extent of motor deficits. We argue that identifying brain networks representative of motor behavior in the resting brain would provide significant insights for current neurorehabilitation approaches. Particularly, we aim to investigate the global configuration of brain rhythms and their relation to motor skill, instead of learning performance as broadly studied. We empirically approach this problem by conducting a three-dimensional physical space visuomotor learning experiment during electroencephalographic (EEG) data recordings with thirty-seven healthy participants. We demonstrate that across-subjects variations in average movement smoothness as the quantified measure of subjects' motor skills can be predicted from the global configuration of resting-state EEG alpha-rhythms (8-14 Hz) recorded prior to the experiment. Importantly, this neural signature of motor skill was found to be orthogonal to (independent of) task- as well as to learning-related changes in alpha-rhythms, which we interpret as an organizing principle of the brain. We argue that disturbances of such configurations in the brain may contribute to motor deficits in stroke, and that reconfiguring stroke patients' brain rhythms by neurofeedback may enhance post-stroke neurorehabilitation. Copyright © 2019, The Authors. All rights reserved.

关键词： Electroencephalography

AIM 2019 challenge on real-world image super-resolution: Methods and results

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arXiv 2019年

作者： Lugmayr, Andreas Danelljan, Martin Timofte, Radu Fritsche, Manuel Gu, Shuhang Purohit, Kuldeep Kandula, Praveen Suin, Maitreya Rajagopalan, A.N. Joon, Nam Hyung Won, Yu Seung Kim, Guisik Kwon, Dokyeong Hsu, Chih-Chung Lin, Chia-Hsiang Huang, Yuanfei Sun, Xiaopeng Lu, Wen Li, Jie Gao, Xinbo Bell-Kligler, Sefi Computer Vision Lab ETH Zurich Indian Institute Of Technology Madras India Image Communication & Signal Processing Laboratory Hanyang University Seoul Korea Republic of CVML Chung-Ang University Department Management Information Systems National Pingtung University of Science and Technology Department of Electrical Engineering National Cheng-Kung University Xidian University Weizmann Institute of Science Israel

This paper reviews the AIM 2019 challenge on real world super-resolution. It focuses on the participating methods and final results. The challenge addresses the real world setting, where paired true high and low-resolution images are unavailable. For training, only one set of source input images is therefore provided in the challenge. In Track 1: Source Domain the aim is to super-resolve such images while preserving the low level image characteristics of the source input domain. In Track 2: Target Domain a set of high-quality images is also provided for training, that defines the output domain and desired quality of the superresolved images. To allow for quantitative evaluation, the source input images in both tracks are constructed using artificial, but realistic, image degradations. The challenge is the first of its kind, aiming to advance the state-of-the-art and provide a standard benchmark for this newly emerging task. In total 7 teams competed in the final testing phase, demonstrating new and innovative solutions to the problem. Copyright © 2019, The Authors. All rights reserved.

关键词： Optical resolving power

Metrics Reloaded: Recommendations for image analysis validation

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arXiv 2022年

作者： Maier-Hein, Lena Reinke, Annika Godau, Patrick Tizabi, Minu D. Buettner, Florian Christodoulou, Evangelia Glocker, Ben Isensee, Fabian Kleesiek, Jens Kozubek, Michal Reyes, Mauricio Riegler, Michael A. Wiesenfarth, Manuel Emre Kavur, A. Sudre, Carole H. Baumgartner, Michael Eisenmann, Matthias Heckmann-Nötzel, Doreen Rädsch, Tim Acion, Laura Antonelli, Michela Arbel, Tal Bakas, Spyridon Benis, Arriel Blaschko, Matthew B. Jorge Cardoso, M. Cheplygina, Veronika Cimini, Beth A. Collins, Gary S. Farahani, Keyvan Ferrer, Luciana Galdran, Adrian Ginneken, Bram Van Haase, Robert Hashimoto, Daniel A. Hoffman, Michael M. Huisman, Merel Jannin, Pierre Kahn, Charles E. Kainmueller, Dagmar Kainz, Bernhard Karargyris, Alexandros Karthikesalingam, Alan Kenngott, Hannes Kofler, Florian Kopp-Schneider, Annette Kreshuk, Anna Kurc, Tahsin Landman, Bennett A. Litjens, Geert Madani, Amin Maier-Hein, Klaus Martel, Anne L. Mattson, Peter Meijering, Erik Menze, Bjoern Moons, Karel G.M. Müller, Henning Nichyporuk, Brennan Nickel, Felix Petersen, Jens Rajpoot, Nasir Rieke, Nicola Saez-Rodriguez, Julio Sánchez, Clara I. Shetty, Shravya Smeden, Maarten Van Summers, Ronald M. Taha, Abdel A. Tiulpin, Aleksei Tsaftaris, Sotirios A. Calster, Ben Van Varoquaux, Gaël Jäger, Paul F. Heidelberg Division of Intelligent Medical Systems and HI Helmholtz Imaging Germany Faculty of Mathematics and Computer Science and Medical Faculty Heidelberg University Heidelberg Germany NCT Heidelberg a partnership between DKFZ University Medical Center Heidelberg Germany Faculty of Mathematics and Computer Science Heidelberg University Heidelberg Germany Heidelberg Division of Intelligent Medical Systems Germany partner site Frankfurt/Mainz a partnership between DKFZ and UCT Frankfurt-Marburg Germany Heidelberg Goethe University Frankfurt Germany Department of Medicine Goethe University Frankfurt Germany Department of Informatics Frankfurt Cancer Insititute Germany Department of Computing Imperial College London London United Kingdom Heidelberg Division of Medical Image Computing and HI Applied Computer Vision Lab Germany Institute for AI in Medicine University Medicine Essen Essen Germany Centre for Biomedical Image Analysis Faculty of Informatics Masaryk University Brno Czech Republic ARTORG Center for Biomedical Engineering Research University of Bern Bern Switzerland Department of Radiation Oncology University Hospital Bern University of Bern Bern Switzerland Simula Metropolitan Center for Digital Engineering Oslo Norway UiT The Arctic University of Norway Romsø Norway Heidelberg Division of Biostatistics Germany Heidelberg Division of Intelligent Medical Systems Division of Medical Image Computing HI Applied Computer Vision Lab Germany MRC Unit for Lifelong Health and Ageing UCL Centre for Medical Image Computing Department of Computer Science University College London London United Kingdom School of Biomedical Engineering and Imaging Science King’s College London London United Kingdom Heidelberg Division of Medical Image Computing Germany Instituto de Cálculo CONICET – Universidad de Buenos Aires Buenos Aires Argentina Centre for Medical Image Computing University College London London United Kingdom McGill University Montréal

Increasing evidence shows that flaws in machine learning (ML) algorithm validation are an underestimated global problem. Particularly in automatic biomedical image analysis, chosen performance metrics often do not reflect the domain interest, thus failing to adequately measure scientific progress and hindering translation of ML techniques into practice. To overcome this, we created Metrics Reloaded, a comprehensive framework guiding researchers in the problem-aware selection of metrics. It was developed by a large international consortium in a multi-stage Delphi process and is based on the novel concept of a problem fingerprint – a structured representation of the given problem that captures all aspects that are relevant for metric selection, from the domain interest to the properties of the target structure(s), data set and algorithm output. Based on the problem fingerprint, users are guided through the process of choosing and applying appropriate validation metrics while being made aware of potential pitfalls. Metrics Reloaded targets image analysis problems that can be interpreted as a classification task at image, object or pixel level, namely image-level classification, object detection, semantic segmentation, and instance segmentation tasks. To improve the user experience, we implemented the framework in the Metrics Reloaded online tool. Following the convergence of ML methodology across application domains, Metrics Reloaded fosters the convergence of validation methodology. Its applicability is demonstrated for various biomedical use cases. © 2022, CC BY.

关键词： Semantic Segmentation

Linear Degrees of Freedom for K-user MISO Interference Channels With Blind Interference Alignment

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Linear Degrees of Freedom for K-user MISO Interference Chann...

作者： Yang, Heecheol Shin, Wonjae Lee, Jungwoo Wireless Signal Processing Laboratory Department of Electrical and Computer Engineering Seoul National University Seoul08826 Korea Republic of

In this paper, we characterize the degrees of freedom (DoF) for K-user M × 1 multiple-input single-output interference channels with reconfigurable antennas, which have N-preset modes at the receivers, assuming linear coding strategies in the absence of channel state information at the transmitters, i.e., blind interference alignment. Our linear DoF converse builds on the lemma that if a set of transmit symbols is aligned at their common unintended receivers, those symbols must have independent signal subspace at their corresponding receivers. This lemma arises from the inherent feature that channel state's changing patterns of the links towards the same receiver are always identical, assuming that the coherence time of the channel is long enough. We derive an upper bound for the linear sum DoF, and propose an achievable scheme that exactly achieves the linear sum DoF upper bound when both of the n∗/M=R1 and MK/n∗=R2 are integers, where n∗ denotes the optimal number of preset modes out of N preset modes. For the other cases, where either R1 or R2 is not an integer, we only give some guidelines how the interfering signals are aligned at the receivers to achieve the upper bound. As an extension, we also show the linear sum DoF upper bound for downlink/uplink cellular networks. © 2017 IEEE.

关键词： Channel state information

PRUNE: Dynamic and decidable dataflow for signal processing on heterogeneous platforms

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arXiv 2018年

作者： Boutellier, Jani Wu, Jiahao Huttunen, Heikki Bhattacharyya, Shuvra S. Laboratory of Pervasive Computing Tampere University of Technology Finland Department of Electrical and Computer Engineering University of Maryland United States Laboratory of Signal Processing Tampere University of Technology Finland Department of Electrical and Computer Engineering University of Maryland United States Laboratory of Pervasive Computing Tampere University of Technology Finland

The majority of contemporary mobile devices and personal computers are based on heterogeneous computing platforms that consist of a number of CPU cores and one or more Graphics processing Units (GPUs). Despite the high volume of these devices, there are few existing programming frameworks that target full and simultaneous utilization of all CPU and GPU devices of the platform. This article presents a dataflow-flavored Model of Computation (MoC) that has been developed for deploying signal processing applications to heterogeneous platforms. The presented MoC is dynamic and allows describing applications with data dependent run-time behavior. On top of the MoC, formal design rules are presented that enable application descriptions to be simultaneously dynamic and decidable. Decidability guarantees compile-time application analyzability for deadlock freedom and bounded memory. The presented MoC and the design rules are realized in a novel Open Source programming environment "PRUNE" and demonstrated with representative application examples from the domains of image processing, computer vision and wireless communications. Experimental results show that the proposed approach outperforms the state-of-the-art in analyzability, flexibility and performance. Copyright © 2018, The Authors. All rights reserved.

关键词： computer aided design

POLAR SEA ICE THICKNESS AND MELT POND FRACTION MEASUREMENTS WITH MULTI-FREQUENCY BISTATIC RADAR POLARIMETRIC AND INTERFEROMETRIC REFLECTOMETRY

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POLAR SEA ICE THICKNESS AND MELT POND FRACTION MEASUREMENTS ...

IEEE International Geoscience and Remote Sensing Symposium

作者： Son V. Nghiem Donald K. Perovich Christopher Polashenski Stephen T. Lowe Rashmi Shah Anthony J. Mannucci Adriano Camps Estel Cardellach Leung Tsang Jiyue Zhu Shurun Tan Jet Propulsion Laboratory California Institute of Technology Pasadena California USA Thayer School of Engineering Dartmouth College Hanover New Hampshire USA Cold Regions Research and Engineering Laboratory Hanover New Hampshire USA Department of Signal Theory and Communications Univ. Politècnica de Catalunya Barcelona Spain Instituto de Ciencias del Espacio (ICE-CSIC/IEEC) Barcelona Spain Department of Electrical Eng. and Computer Sci. Univ. of Michigan Ann Arbor Michigan USA

Arctic and Antarctic sea ice covers are in a sharp contrast in terms of characteristics, distributions, and processes with a drastic decrease in the Arctic versus the opposite increase in the Antarctic in a changing climate. In quantifying polar sea ice differences to address the contrasted sea ice behaviors, two key parameters are sea ice thickness and melt pond fraction, which remain challenging to measure extensively in time and in space with a sustainable approach. Here, we present a new paradigm for such measurements using bistatic radar reflectometry, thanks to developments of low-cost receivers to acquire reflected signals from numerous existing transmitter systems operated at multiple frequencies to be replenished and sustained indefinitely into the future. For sea ice thickness measurement to determine ice volume, reflected signals likely come from the bottom ice-water interface avoiding large errors inherent in current altimetry techniques due to uncertainty in free-board height and snow cover. Regarding melt pond faction on sea ice to estimate albedo and insolation, the bistatic reflection can be dominated by melt pond water with permittivity that is one order of magnitude larger compared to that of snow or ice. These are examined by a combination of numerical Kirchhoff (KA) simulator and Numerical Maxwell Model of 3D simulations (NMM3D) to preserve phase and amplitude information and thereby account for both coherent and incoherent effects. Physical insights from the rigorous theory for bistatic radar reflectometry will be valuable to develop future satellite missions to resolve cryospheric science issues concerning the polar sea ice differences.

关键词： Sea ice Reflectometry Sea measurements Thickness measurement Arctic Satellites

Neural Signatures of Motor Skill in the Resting Brain

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Neural Signatures of Motor Skill in the Resting Brain

IEEE International Conference on Systems, Man and Cybernetics

作者： Ozan Özdenizci Timm Meyer Felix Wichmann Jan Peters Bernhard Schölkopf Müjdat Çetin Moritz Grosse-Wentrup Department of Electrical and Computer Engineering Northeastern University Boston MA United States Max Planck Institute for Intelligent Systems Tübingen Germany Faculty of Science University of Tübingen and Bernstein Center for Computational Neuroscience Tübingen Tübingen Germany FG Intelligente Autonome Systeme Technische Universität Darmstadt Darmstadt Germany Signal Processing and Information Systems Laboratory Faculty of Engineering and Natural Sciences Sabanci University Istanbul Turkey

Stroke-induced disturbances of large-scale cortical networks are known to be associated with the extent of motor deficits. We argue that identifying brain networks representative of motor behavior in the resting brain would provide significant insights for current neurorehabilitation approaches. Particularly, we aim to investigate the global configuration of brain rhythms and their relation to motor skill, instead of learning performance as broadly studied. We empirically approach this problem by conducting a three-dimensional physical space visuomotor learning experiment during electroencephalographic (EEG) data recordings with thirty-seven healthy participants. We demonstrate that across-subjects variations in average movement smoothness as the quantified measure of subjects' motor skills can be predicted from the global configuration of resting-state EEG alpha-rhythms (8-14 Hz) recorded prior to the experiment. Importantly, this neural signature of motor skill was found to be orthogonal to (independent of) task-as well as to learning-related changes in alpha-rhythms, which we interpret as an organizing principle of the brain. We argue that disturbances of such configurations in the brain may contribute to motor deficits in stroke, and that reconfiguring stroke patients' brain rhythms by neurofeedback may enhance post-stroke neurorehabilitation.

关键词： Electroencephalography End effectors Task analysis Integrated circuits Stroke (medical condition) Planning Visualization

Application of LDPC Codes on PUF Error Correction Based on Code-offset Construction

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Application of LDPC Codes on PUF Error Correction Based on C...

2017 IEEE 12th International Conference on ASIC

作者： Kai Sun Yingjie Lao Weiqiang Liu Xiaohu You Chuan Zhang Lab of Efficient Architectures for Digital-communication and Signal-processing(LEADS) National Mobile Communications Research Laboratory Southeast University Department of Electrical and Computer Engineering Clemson University College of Electronic and Information Engineering NUAA

ISBN: (纸本)9781509066261;9781509066254

As a newly emerging technology,physical unclonable functions(PUFs) have drawn a lot of *** their cryptographic applications,error correction is an indispensable component to fight against environmental factors which influence PUFs' ***,BCH codes have been applied to the error correction part to enhance the stability of an cryptographic system using *** this paper,low-density parity-check(LDPC) codes are first used to correct errors caused by environmental factors and shown to perform better than BCH codes in some *** addition,normalized minsum algorithm has been considered to balance the performance and complexity of LDPC decoding.

关键词： Physical unclonable functions(PUFs) lowdensity parity-check(LDPC) codes key reproduction error correction