检索结果-内蒙古大学图书馆

On the precision of neural computation with interaural time differences in the medial superior olive

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Marsalek, Petr Sanda, Pavel Bures, Zbynek Institute of Pathological Physiology First Medical Faculty Charles University in Prague U Nemocnice 5/478 Praha 2128 53 Czech Republic Department of Radioelectronics Faculty of Electrical Engineering Czech Technical University in Prague Technická 2/1902 Praha 6166 27 Czech Republic Institute of Computer Science Czech Academy of Sciences Pod Vodárenskou věží 2/271 Praha 8182 07 Czech Republic Czech Institute of Informatics Robotics and Cybernetics Czech Technical University in Prague Jugoslávských partyzánů 4/1903 Praha 6166 36 Czech Republic College of Polytechnics Tolstého 16/1556 Jihlava586 01 Czech Republic

Incoming sound is in cochlea and auditory nerve encoded into spike trains. At the third neuron of the auditory pathway, spike trains of the left and right sides are processed in brainstem nuclei to yield sound localization information. Two different localization encoding mechanisms are employed in two "centers" for low and high sound frequencies in the brainstem. The centers are superior olivary nuclei, medial and lateral. This paper contains analytical estimates of parameters needed in description of auditory coding in sound localization neural circuit. Our model spike trains are based on electro-physiological recordings. We arrive to best estimates for neuronal signaling with the use of just noticeable difference of the ideal observer. We describe spike timing jitter and its role in the spike train processing. We study frequency dependence of spike trains on the sound frequency. All parameters are accompanied with detailed estimates of their values and variability. Intervals bounding all the parameter from lower and higher values are discussed. Copyright © 2020, The Authors. All rights reserved.

关键词： Neurons

Terahertz Faraday and Kerr rotation spectroscopy of Bi1−xSbx films in high magnetic fields up to 30 tesla

学校读者我要写书评

暂无评论

Physical Review B 2019年第11期100卷 115145-115145页

作者： Xinwei Li Katsumasa Yoshioka Ming Xie G. Timothy Noe, II Woojoo Lee Nicolas Marquez Peraca Weilu Gao Toshio Hagiwara Ørjan S. Handegård Li-Wei Nien Tadaaki Nagao Masahiro Kitajima Hiroyuki Nojiri Chih-Kang Shih Allan H. MacDonald Ikufumi Katayama Jun Takeda Gregory A. Fiete Junichiro Kono Department of Electrical and Computer Engineering Rice University Houston Texas 77005 USA Department of Physics Graduate School of Engineering Yokohama National University Yokohama 240-8501 Japan Department of Physics and Center for Complex Quantum Systems The University of Texas at Austin Austin Texas 78712 USA Department of Physics and Astronomy Rice University Houston Texas 77005 USA National Institute for Materials Science Tsukuba Ibaraki 305-0044 Japan Institute for Materials Research Tohoku University Sendai 980-8577 Japan Department of Physics Northeastern University Boston Massachusetts 02115 USA Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Material Science and NanoEngineering Rice University Houston Texas 77005 USA

We report results of terahertz Faraday and Kerr rotation spectroscopy measurements on thin films of Bi1−xSbx, an alloy system that exhibits a semimetal-to-topological-insulator transition as the Sb composition x increases. By using a single-shot time-domain terahertz spectroscopy setup combined with a table-top pulsed minicoil magnet, we conducted measurements in magnetic fields up to 30 T, observing distinctly different behaviors between semimetallic (x<0.07) and topological insulator (x>0.07) samples. Faraday and Kerr rotation spectra for the semimetallic films showed a pronounced dip that blueshifted with the magnetic field, whereas spectra for the topological insulator films were positive and featureless, increasing in amplitude with increasing magnetic field and eventually saturating at high fields (>20 T). Ellipticity spectra for the semimetallic films showed resonances, whereas the topological insulator films showed no detectable ellipticity. To explain these observations, we developed a theoretical model based on realistic band parameters and the Kubo formula for calculating the optical conductivity of Landau-quantized charge carriers. Our calculations quantitatively reproduced all experimental features, establishing that the Faraday and Kerr signals in the semimetallic films predominantly arise from bulk hole cyclotron resonances while the signals in the topological insulator films represent combined effects of surface carriers originating from multiple electron and hole pockets. These results demonstrate that the use of high magnetic fields in terahertz magnetopolarimetry, combined with detailed electronic structure and conductivity calculations, allows us to unambiguously identify and quantitatively determine unique contributions from different species of carriers of topological and nontopological nature in Bi1−xSbx.

关键词： Faraday effect Kerr effect Topological materials Terahertz spectroscopy

11 TeraFLOPs per second photonic convolutional accelerator for deep learning optical neural networks

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Xu, Xingyuan Tan, Mengxi Corcoran, Bill Wu, Jiayang Boes, Andreas Nguyen, Thach G. Chu, Sai T. Little, Brent E. Hicks, Damien G. Morandotti, Roberto Mitchell, Arnan Moss, David J. Optical Sciences Centre Swinburne University of Technology HawthornVIC3122 Australia Department of Electrical and Computer Systems Engineering Monash University ClaytonVIC3800 Australia School of Engineering RMIT University MelbourneVIC3001 Australia Department of Physics City University of Hong Kong Tat Chee Avenue Hong Kong Xi’an Institute of Optics and Precision Mechanics Precision Mechanics of CAS Xi’an China Bioinformatics Division Walter & Eliza Hall Institute of Medical Research ParkvilleVIC3052 Australia INRS-Énergie Matériaux et Télécommunications 1650 Boulevard Lionel-Boulet VarennesQCJ3X 1S2 Canada Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu610054 China

Convolutional neural networks (CNNs), inspired by biological visual cortex systems, are a powerful category of artificial neural networks that can extract the hierarchical features of raw data to greatly reduce the network parametric complexity and enhance the predicting accuracy. They are of significant interest for machine learning tasks such as computer vision, speech recognition, playing board games and medical diagnosis [1-7]. Optical neural networks offer the promise of dramatically accelerating computing speed to overcome the inherent bandwidth bottleneck of electronics. Here, we demonstrate a universal optical vector convolutional accelerator operating beyond 10 Tera-FLOPS (floating point operations per second), generating convolutions of images of 250,000 pixels with 8-bit resolution for 10 kernels simultaneously — enough for facial image recognition. We then use the same hardware to sequentially form a deep optical CNN with ten output neurons, achieving successful recognition of full 10 digits with 900 pixel handwritten digit images with 88% accuracy. Our results are based on simultaneously interleaving temporal, wavelength and spatial dimensions enabled by an integrated microcomb source. This approach is scalable and trainable to much more complex networks for demanding applications such as unmanned vehicle and real-time video recognition. © 2020, CC BY.

关键词： Convolution

Isolation enhancement between two closely spaced rectangular patches for MIMO applications 12

学校读者我要写书评

暂无评论

Isolation enhancement between two closely spaced rectangular...

12th European Conference on Antennas and Propagation, EuCAP 2018

作者： Hammoodi, Ali I. Bakr, Mustafa S. Khaleel, Haider Milanova, Mariofanna Department of Systems Engineering University of Arkansas at Little Rock Little Rock United States School of Electronic and Electrical Engineering University of Leeds Leeds United Kingdom Institute of Microwave and Phonetic Engineering Graz University of Technology Austria Physics Department Xavier University CincinnatiOH United States Department of Computer Science University of Arkansas at Little Rock Little Rock United States

ISBN: (纸本)9781785617911

This paper presents the design of antenna array with decoupling structure to enhance the isolation between two closely spaced rectangular patches. The design is built on RO3003 substrate with a relative permittivity of 3 and a thickness of 1.52 mm. The decoupling structure is a rectangular strip with one dimensional periodic structure of circular slots placed orthogonally between the two patches. A single via is inserted at the center of the rectangular strip to discharge the mutual current to the ground plane underneath. The array achieved a coupling reduction of 13 dB at 5.8 GHz with edge-to-edge separation of 0.19 λo. The measured gain of single antenna after the decoupling is 6.3 dBi. The array is suitable for MIMO applications where high isolation and compact size array are required. © Institution of engineering and *** Rights Reserved.

关键词： Periodic structures

Corrigendum to “Unpacking the drivers of diurnal dynamics of sun-induced chlorophyll fluorescence (SIF): Canopy structure, plant physiology, instrument configuration and retrieval methods” [Remote Sensing of Environment 265 (2021) 112672]

学校读者我要写书评

暂无评论

Remote Sensing of Environment 2022年 268卷

作者： Christine Y. Chang Jiaming Wen Jimei Han Oz Kira Julie LeVonne Jeffrey Melkonian Susan J. Riha Joseph Skovira Sharon Ng Lianhong Gu Jeffrey D. Wood Paul Näthe Ying Sun USDA Agricultural Research Service Adaptive Cropping Systems Laboratory Beltsville MD USA School of Integrative Plant Science Soil and Crop Sciences Section Cornell University Ithaca NY USA Department of Atmospheric and Earth Sciences Cornell University Ithaca NY USA Department of Electrical and Computer Engineering Cornell University Ithaca NY USA Environmental Sciences Division and Climate Change Science Institute Oak Ridge National Laboratory Oak Ridge TN USA School of Natural Resources University of Missouri Columbia MO USA JB Hyperspectral Devices GmbH Düsseldorf Germany

11.0 Tera-FLOP/second photonic convolutional accelerator for deep learning optical neural networks

学校读者我要写书评

暂无评论

TechRxiv

TechRxiv 2020年

作者： Moss, David J. Xu, Xingyuan Tan, Mengxi Corcoran, Bill Wu, Jiayang Boes, Andreas Nguyen, Thach G. Chu, Sai T. Little, Brent E. Hicks, Damien G. Morandotti, Roberto Mitchell, Arnan Optical Sciences Centre Swinburne University of Technology HawthornVIC3122 Australia Department of Electrical and Computer Systems Engineering Monash University ClaytonVIC3800 Australia School of Engineering RMIT University MelbourneVIC3001 Australia Department of Physics City University of Hong Kong Tat Chee Avenue Hong Kong Hong Kong Xi’an Institute of Optics and Precision Mechanics Precision Mechanics of CAS Xi’an China Bioinformatics Division Walter & Eliza Hall Institute of Medical Research ParkvilleVIC3052 Australia INRS-Énergie Matériaux et Télécommunications 1650 Boulevard Lionel-Boulet VarennesQCJ3X 1S2 Canada Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu610054 China

关键词： Convolutional neural networks

Photonic radio frequency and microwave integration based on a multi-wavelength 49GHz Kerr microcomb source

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Xu, Xingyuan Tan, Mengxi Wu, Jiayang Boes, Andreas Corcoran, Bill Nguyen, Thach G. Chu, Sai T. Little, Brent E. Morandotti, Roberto Mitchell, Arnan Moss, David J. Centre for Micro-Photonics Swinburne University of Technology HawthornVIC3122 Australia School of Engineering RMIT University MelbourneVIC3001 Australia Department of Electrical and Computer Systems Engineering Monash University ClaytonVIC3800 Australia Department of Physics City University of Hong Kong Tat Chee Avenue Hong Kong Hong Kong State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Science Xi'an China INSR-Énergie Matériaux et Télécommunications 1650 Boulevard Lionel-Boulet VarennesQCJ3X 1S2 Canada

We demonstrate a photonic RF integrator based on an integrated soliton crystal micro-comb source. By multicasting and progressively delaying the input RF signal using a transversal structure, the input RF signal is integrated discretely. Up to 81 wavelengths are provided by the microcomb source, which enable a large integration time window of ~6.8 ns, together with a time resolution as fast as ~84 ps. We perform signal integration of a diverse range of input RF signals including Gaussian pulses with varying time widths, dual pulses with varying time intervals and a square waveform. The experimental results show good agreement with theory. These results verify our microcomb-based integrator as a competitive approach for RF signal integration with high performance and potentially lower cost and footprint. Copyright © 2020, The Authors. All rights reserved.

关键词： Multicasting

AGlobal benchmark of algorithms for segmentinglate gadolinium-enhanced cardiac magnetic resonance imaging

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Xiong, Zhaohan Xia, Qing Hu, Zhiqiang Huang, Ning Bian, Cheng Zheng, Yefeng Vesal, Sulaiman Ravikumar, Nishant Maier, Andreas Yang, Xin Heng, Pheng-Ann Ni, Dong Li, Caizi Tong, Qianqian Si, Weixin Puybareau, Elodie Khoudli, Younes Géraud, Thierry Chen, Chen Bai, Wenjia Rueckert, Daniel Xu, Lingchao Zhuang, Xiahai Luo, Xinzhe Jia, Shuman Sermesant, Maxime Liu, Yashu Wang, Kuanquan Borra, Davide Masci, Alessandro Corsi, Cristiana De Vente, Coen Veta, Mitko Karim, Rashed Preetha, Chandrakanth Jayachandran Engelhardt, Sandy Qiao, Menyun Wang, Yuanyuan Tao, Qian Nuñez-Garcia, Marta Camara, Oscar Savioli, Nicolo Lamata, Pablo Zhao, Jichao Auckland Bioengineering Institute University of Auckland Auckland New Zealand State Key Lab of Virtual Reality Technology and Systems Beihang University Beijing China School of Electronics Engineering and Computer Science Peking University Beijing China SenseTime Inc Shenzhen China Tencent Jarvis Laboratory Shenzhen China Pattern Recognition Lab Friedrich-Alexander-Universität Erlangen-Nürnberg Erlangen Germany Department of Computer Science and Engineering Chinese University of Hong Kong Hong Kong National-Regional Key Technology Engineering Laboratory for Medical Ultrasound School of Biomedical Engineering Shenzhen University Shenzhen China School of Computer Science Wuhan University Wuhan China Shenzhen Key Laboratory of Virtual Reality and Human Interaction Technology Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen China Epita Research and Development Laboratory Paris France Department of Computing Imperial College London London United Kingdom School of Naval Architecture Shanghai Jiao Tong University Ocean & Civil Engineering Shanghai China School of Data Science Fudan University Shanghai China Epione Research Group Universite Cote d'Azur Inria Sophia Antipolis France Harbin Institute of Technology School of Computer Science and Technology Harbin China Department of Electric University of Bologna Electronic and Information Engineering Cesena Italy Department of Biomedical Engineering Eindhoven University of Technology Eindhoven Netherlands School of Biomedical Engineering and Imaging Sciences Kings College London London United Kingdom Faculty of Electrical Engineering and Information Technology University of Magdeburg Magdeburg Germany Heidelberg University Hospital Germany Biomedical Engineering Center Fudan University Shanghai China Department of Radiology Leiden University Medical Center Leiden Netherlands Department of Information and Communication Technologies Universitat Pompeu Fabra Barcelona Spain D

Segmentation of cardiac images, particularly late gadolinium-enhanced magnetic resonance imaging (LGE-MRI)widely used for visualizing diseased cardiacstructures, is a crucial first step for clinical diagnosis and treatment. However, direct segmentation ofLGE-MRIsischallenging due to *** most clinical studies have relied on manual and labor-intensive approaches, automatic methods are of high interest, particularly optimized machine learning *** address this, we organized the "2018 Left Atrium Segmentation Challenge" using 154 3D LGE-MRIs, currently the world's largest cardiac LGE-MRI dataset, and associated labels of the left atriumsegmented by three medical experts,ultimately attractingthe participation of27 international teams. In this paper, extensive analysis of the submitted algorithms using technical and biological metrics was performed by undergoing subgroup analysis and conducting hyper-parameter analysis,offeringan overall picture ofthe major design choices of convolutional neural networks(CNNs) and practical considerations for achieving state-of-the-art left atrium segmentation. Results show the top methodachieved a dice score of 93.2%and a mean surface to a surface distance of 0.7mm, significantly outperforming prior state-of-the-art. Particularly, our analysisdemonstrated that double, sequentially usedCNNs, in which a first CNN is used for automatic region-of-interestlocalization and a subsequent CNN is used for refinedregional segmentation, achieved far superiorresults than traditional methods and pipelinescontaining *** findings from this study can potentially be extended to other imaging datasets and modalities, having an impact on the wider medical imaging *** large-scale benchmarking study makes a significant step towards much-improved segmentation methods for cardiac LGE-MRIs, and will serveas animportant benchmark for evaluating and comparing the future works in the field. Copyright © 2020, Th

关键词： Magnetic resonance imaging

Efficient Inverse Kinematics for Redundant Manipulators with Collision Avoidance in Dynamic Scenes

学校读者我要写书评

暂无评论

Efficient Inverse Kinematics for Redundant Manipulators with...

IEEE International Conference on robotics and Biomimetics

作者： Liangliang Zhao Jingdong Zhao Hong Liu Dinesh Manocha Department of Computer Science and Electrical & Computer Engineering University of Maryland at College Park MD USA State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781728103785;9781728103778

We present a novel iterative algorithm for inverse kinematics of redundant manipulators in dynamic environments. Our approach uses an iterative approach to generate valid configurations and selects an inverse kinematics solution using a rank-based selection strategy. To avoid the moving obstacles, we combine our inverse kinematics method with a collision avoidance scheme. We highlight the performance of our algorithm on different high DOF manipulators in a dynamic scene.

关键词： Kinematics Manipulator dynamics Collision avoidance Iterative methods End effectors Trajectory