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Nonlinear dynamics of topological helicity wave in a frustrated skyrmion string

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arXiv 2022年

作者： Xia, Jing Zhang, Xichao Liu, Xiaoxi Zhou, Yan Ezawa, Motohiko Department of Electrical and Computer Engineering Shinshu University Wakasato 4-17-1 Nagano380-8553 Japan School of Science and Engineering The Chinese University of Hong Kong Guangdong Shenzhen518172 China Department of Applied Physics The University of Tokyo 7-3-1 Hongo Tokyo113-8656 Japan

A skyrmion in frustrated magnetic system has the helicity degree of freedom. A skyrmion string is formed in a frustrated layered system, which is well described by the XY model owing to the exchange coupling between adjacent layers. We consider a system where the interlayer exchange couplings are alternating, where the dimerized XY model is materialized, whose linear limit is the Su-Schrieffer-Heeger model. We argue that it is a nonlinear topological system. We study the quench dynamics of the helicity wave under the initial condition that the helicity of the skyrmion in the bottommost layer is rotated. It yields a good signal to detect whether the system is topological or trivial. Our results show that the helicity dynamics of the skyrmion string have a rich physics in the modulated exchange-coupled system. © 2022, CC BY.

关键词： Dynamics

Stability analysis of a dark energy model in Rastall gravity

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arXiv 2024年

作者： Shaily Singh, Akanksha Singh, J.K. Hussain, Saddam Myrzakulov, Ratbay Department of Mathematics Netaji Subhas University of Technology New Delhi110 078 India School of Computer Science Engineering and Technology Bennett University Greater Noida India Department of Physics Indian Institute of Technology Uttar Pradesh Kanpur208016 India Ratbay Myrzakulov Eurasian International Centre for Theoretical Physics Astana Kazakhstan

We study a cosmological model in Rastall’s theory of gravity in the framework of the flat FLRW metric. We formulate the value of the Hubble parameter, which contains two model parameters, α and j. Employing the Markov Chain Monte Carlo (MCMC) sampling technique, we determine the values of these model parameters along with their uncertainties. Moreover, we derive the equation of state (EoS) parameter, which converges around the quintessence region. We perform a dynamical system analysis using the linearization technique to validate the results independently. Also, we discuss various physical attributes of the model, highlighting the transition to acceleration and the violation of the strong energy condition (SEC) in the late stages of evolution. In conclusion, our model mimics the behavior of a dark matter fluid during the past epoch and transitions into a quintessence dark energy model in the future epoch. © 2024, CC BY.

关键词： Equations of state

Determination of the spectral dispersion for the heart muscle - A Kramers-Kronig approach

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Determination of the spectral dispersion for the heart muscl...

2024 International Conference Laser Optics, ICLO 2024

作者： Oliveira, Luís M. Pinheiro, Maria R. Oliveira, Hélder P. Carvalho, Maria I. Tuchin, Valery V. Polytechnic of Porto School of Engineering Physics Department Rua Dr. António Bernardino de Almeida 431 Porto4200-072 Portugal Rua Dr. Roberto Frias Porto4200-465 Portugal Porto University Faculty of Science Department of Computer Science Rua do Campo Alegre 1021 Porto4169-007 Portugal Porto University Faculty of Engineering Rua Dr. Roberto Frias Porto4200-465 Portugal Saratov State University Institute of Physics and Science Medical Center 83 Astrakhanskaya str. Saratov410012 Russia Tomsk State University Laboratory of Laser Molecular Imaging and Machine Learning 36 Lenin ave. Tomsk634050 Russia A.N. Bach Institute of Biophotonics Rc 'Biotechnology of the Russian Academy of Sciences' 33 Leninsky prospect build 2 Moscow119071 Russia

ISBN: (纸本)9798350390674

The refractive index of the pigs heart was measured at wavelengths between 255 and 850 nm to calculate the dispersion. The total transmittance and total reflectance spectra of the pig heart were measured between 200 and 1000 nm to calculate the spectral absorption coefficient. Using Kramers-Kronig relations, the dispersion of the heart was matched to experimental refractive index values. © 2024 IEEE.

关键词： Mammals

IAC-17.B6.2.12: Advantages of 3D printing technology to operations in future human exploration of mars 68

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IAC-17.B6.2.12: Advantages of 3D printing technology to oper...

68th International Astronautical Congress: Unlocking Imagination, Fostering Innovation and Strengthening Security, IAC 2017

作者： Coen, Mauricio Morrell, Benjamin Kim, Deliya Müller, Michael Gruber, Sophie Campbell, Rhys Brady, Matthew Fairleigh, Shelby Enciso, Valeria Chamitoff, Greg Texas A and M University College StationTX77840 United States School of Aerospace Mechanical and Mechatronic Engineering University of Sydney NSW2006 Australia P.C. Rossin College of Engineering and Applied Science Lehigh University 19 Memorial Dr W BethlehemPA18015 United States Faculty of Mathematics Physics and Geodesy Graz University of Technology Petersgasse 16 Graz Steiermark8010 Austria Faculty of Mathematics Computer Science and Physics University of Innsbruck Technikerstraße 13 Innsbruck6020 Austria University of Wollongong 51 Barrack Ave Barrack-PointNSW2528 Australia Texas A and M University 8113 Pilgrims Pl AustinTX United States Department of Ecosystem Science and Management Texas A and M University 400 Bizzell St College StationTX77843 United States Aerospace Department Texas A and M University College StationTX77840 United States

ISBN: (纸本)9781510855373

Geological field work is an important goal that has to be executed during a human mission to Mars. To make sure that all experiments during a mission to Mars can be conducted properly, it is crucial that tools can be quickly repaired or replaced, without reliance on Earth, and 3D printing can provide that capability. Additionally, 3D printing has the potential to produce tools on an as-needed basis for newly identified needs. We tested the operational workflow of using 3D printing in the Poland Mars Analog Simulation 2017 [1]. Previous analog studies identified the need for an Earth independent approach for Mars operations, especially because of the time delay in Earth-Mars communications [6]. Additionally, flexibility in human Mars operations has been identified as an important capability. We test the hypotheses that a 3D printer can assist operations in a) being more flexible and b) more independent of Earth. These will be assessed by observing how quickly the operational procedures can be executed, how efficiently the analog astronauts can use the technology and how the use of 3D printers can provide operational adaptability to print tools on demand and improve mission robustness. Preliminary findings from the experimental results identified the utility of a 3D printer to support geological field work, and to adapt to unplanned issues, although to maximise the benefit, the technology needs to be made more robust, and operational procedures need to be adapted to suit the use of a 3D printer. Evidence from the experiments suggested some benefit for 3D printers enabling greater independence of Earth, but with a reliance on Earth-based expertise. Further analysis and investigations are being pursued to fully assess the hypotheses. © Copyright (2017) by International Astronautical Federation All rights reserved.

关键词： 3D printers

On-Demand Magnon Resonance Isolation in Cavity Magnonics

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arXiv 2024年

作者： Pishehvar, Amin Wang, Zhaoyou Zhu, Yujie Jiang, Yu Yan, Zixin Li, Fangxin Jornet, Josep M. Hu, Jia-Mian Jiang, Liang Zhang, Xufeng Department of Electrical and Computer Engineering Northeastern University BostonMA02115 United States Pritzker School of Molecular Engineering University of Chicago ChicagoIL60637 United States Department of Materials Science and Engineering University of Wisconsin - Madison MadisonWI53706 United States Department of Physics Northeastern University BostonMA02115 United States

Cavity magnonics is a promising field focusing the interaction between spin waves (magnons) and other types of signals. In cavity magnonics, the function of isolating magnons from the cavity to allow signal storage and processing fully in the magnonic domain is highly desired, but its realization is often hindered by the lack of necessary tunability on the interaction. This work shows that by utilizing the collective mode of two YIG spheres and adopting Floquet engineering, magnonic signals can be switched on-demand to a magnon dark mode that is protected from the environment, enabling a variety of manipulation over the magnon dynamics. Our demonstration can be scaled up to systems with an array of magnonic resonators, paving the way for large-scale programmable hybrid magnonic circuits. Copyright © 2024, The Authors. All rights reserved.

关键词： Spin waves

Advances in solar adaptive optics system at the domeless solar telescope of the hida observatory

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Advances in solar adaptive optics system at the domeless sol...

Astronomical and Space Optical Systems

作者： Miura, Noriaki Noto, Yuuki Kato, Shuusuke Yokoyama, Fumihito Kuwamura, Susumu Baba, Naoshi Hanaoka, Yoichiro Nagata, Shin'ichi Ueno, Satoru Kitai, Reizaburou Ichimoto, Kiyoshi Takami, Hideki Department of Computer Sciences Kitami Institute of Technology 165 Koen-cho Kitami Hokkaido 090-8507 Japan Division of Applied Physics Graduate School of Engineering Hokkaido University Sapporo Hokkaido 060-8628 Japan National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Hida Observatory Graduate School of Science Kyoto University Kamitakara Takayama Gifu 506-1314 Japan Subaru Telescope National Astronomical Observatory of Japan 650 North A'ohoku Place Hilo HI 96720 United States

ISBN: (纸本)9780819477293

A solar adaptive optics system for the 60 cm domeless solar telescope of the Hida Observatory in Japan is developed. A high-speed deformable mirror with 52 electromagnetic actuators is newly used in an experimental adaptive optics system. The use of the mirror resulted in the improvement of Strehl ratios in laboratory experiments. In solar observations, the system worked well when solar granulation was used as a target for wavefront sensing. An adaptive optics system being developed for a vertical spectrograph of the domeless solar telescope is described. © 2009 SPIE.

关键词： Adaptive optics

A Fully Programmable On-Chip Planar Waveguide for Machine Learning

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A Fully Programmable On-Chip Planar Waveguide for Machine Le...

Conference on Lasers and Electro-Optics (CLEO)

作者： Martin M. Stein Tatsuhiro Onodera Benjamin A. Ash Mandar M. Sohoni Melissa Bosch Ryotatsu Yanagimoto Marc Jankowski Timothy P. McKenna Tianyu Wang Gennady Shvets Maxim R. Shcherbakov Logan G. Wright Peter L. McMahon School of Applied and Engineering Physics Cornell University Ithaca NY USA NTT Physics and Informatics Laboratories NTT Research Inc. Sunnyvale CA USA E. L. Ginzton Laboratory Stanford University Stanford CA USA Department of Electrical Engineering and Computer Science UC Irvine Irvine CA USA Department of Applied Physics Yale University New Haven CT USA Kavli Institute at Cornell for Nanoscale Science Cornell University Ithaca NY USA

We introduce a device containing a planar waveguide whose spatial refractive index profile $n(x, z)$ can be programmed in real time. We demonstrate use this device as an optical neural network.

ISBN: (纸本)9798350369311

We introduce a device containing a planar waveguide whose spatial refractive index profile $n(x, z)$ can be programmed in real time. We demonstrate use this device as an optical neural network.

关键词： Optical planar waveguides Refractive index Waveguide lasers Optical fiber networks Optical variables control Real-time systems Planar waveguides System-on-chip Optical refraction Optical devices

EG-SPIKEFORMER: EYE-GAZE GUIDED TRANSFORMER ON SPIKING NEURAL NETWORKS FOR MEDICAL IMAGE ANALYSIS

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arXiv 2024年

作者： Pan, Yi Jiang, Hanqi Chen, Junhao Li, Yiwei Zhao, Huaqin Zhou, Yifan Shu, Peng Wu, Zihao Liu, Zhengliang Zhu, Dajiang Li, Xiang Abate, Yohannes Liu, Tianming School of Computing University of Georgia AthensGA United States Department of Computer Science and Engineering University of Texas ArlingtonTX United States Department of Radiology Massachusetts General Hospital Harvard Medical School MA United States Department of Physics and Astronomy University of Georgia AthensGA United States

Neuromorphic computing has emerged as a promising energy-efficient alternative to traditional artificial intelligence, predominantly utilizing spiking neural networks (SNNs) implemented on neuromorphic hardware. Significant advancements have been made in SNN-based convolutional neural networks (CNNs) and Transformer architectures. However, their applications in the medical imaging domain remain underexplored. In this study, we introduce EG-SpikeFormer, an SNN architecture designed for clinical tasks that integrates eye-gaze data to guide the model’s focus on diagnostically relevant regions in medical images. This approach effectively addresses shortcut learning issues commonly observed in conventional models, especially in scenarios with limited clinical data and high demands for model reliability, generalizability, and transparency. Our EG-SpikeFormer not only demonstrates superior energy efficiency and performance in medical image classification tasks but also enhances clinical relevance. By incorporating eye-gaze data, the model improves interpretability and generalization, opening new directions for the application of neuromorphic computing in healthcare. © 2024, CC BY.

关键词： Convolutional neural networks

5GCIDS: An Intrusion Detection System for 5G Core with AI and Explainability Mechanisms

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5GCIDS: An Intrusion Detection System for 5G Core with AI an...

IEEE Globecom Workshops

作者： Panagiotis Radoglou-Grammatikis George Nakas George Amponis Sofia Giannakidou Thomas Lagkas Vasileios Argyriou Sotirios Goudos Panagiotis Sarigiannidis K3Y Ltd Sofia Bulgaria Department of Electrical and Computer Engineering University of Western Macedonia Kozani Greece Department of Computer Science International Hellenic University Kavala Greece Department of Networks and Digital Media Kingston University London Surrey UK School of Physics Aristotle University of Thessaloniki Thessaloniki Greece

The progression of fifth-generation (5G) networks provides multiple advantages, such as faster speed, reduced latency and increased capacity. Towards these advancements, it is clear that 5G Core (5GC) represents the heart of a 5G network, providing a variety of new network services such as Ultra-reliable low-latency communication (URLLC) and Massive machine-type communication (mMTC). However, despite the various benefits, 5GC is prone to several cyberthreats that can result in catastrophic effects. In this paper, an Intrusion Detection System (IDS) for 5GC is introduced. The proposed IDS called 5GCIDS adopts Artificial Intelligence (AI) methods in order to detect potential cyberattacks against Packet Forwarding Control Protocol (PFCP), which is utilised for the N4 interface between Session Management Function (SMF) andUser Plane Function (UPF). For the detection process, both Transmission Control Protocol (TCP)/Internet Protocol (IP) flow statistics and application-layer PFCP flow statistics are used. In the second case, we provide a bidirectional flow statistics generator called PFCPFlowMeter. Finally, the detection outcomes are explained as local and global explanations with the TreeSHAP method. The evaluation results demonstrate the efficiency of the proposed IDS.

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