检索结果-内蒙古大学图书馆

Mode-Symmetry-Assisted Optical Pulling by Bound States in the Continuum

Physical Review Letters 2024年第25期132卷 253802-253802页

作者： Hang Li Yongyin Cao Rui Feng Bojian Shi Yuzhi Shi Yang Chen Dongliang Gao Tongtong Zhu Donghua Tang Fangkui Sun Cheng-Wei Qiu Weiqiang Ding Institute of Advanced Photonics School of Physics Institute of Precision Optical Engineering School of Physics Science and Engineering Chinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials Department of Precision Machinery and Precision Instrumentation School of Physical Science and Technology Collaborative Innovation Center of Suzhou Nano Science and Technology School of Optoelectronic Engineering and Instrumentation Science Department of Physics School of Science Department of Electrical and Computer Engineering Collaborative Innovation Center of Extreme Optics

Aside from optical pushing and trapping that have been implemented successfully, the transportation of objects backward to the source by the optical pulling forces (OPFs) has attracted tremendous attention, which was usually achieved by increasing the forward momentum of light. However, the limited momentum transfer between light and object greatly constrains the amplitudes of OPFs. Here, we present a mechanism to generate strong interactions between object and background through the bound states in the continuums, which can generate large OPFs without increasing the forward momentum of light. The underlying physics is the extraction of momentum from the designed background lattice units assisted by mode symmetry. This work paves the way for extraordinary optical manipulations and shows great potential for exploring the momenta of light in media.

关键词： Mechanical effects of light on material media Nanophotonics Photonic crystals

来源：评论

学校读者我要写书评

暂无评论

FedRC: A Rapid-Converged Hierarchical Federated Learning Framework in Street Scene Semantic Understanding

arXiv

引用

arXiv 2024年

作者： Kou, Wei-Bin Lin, Qingfeng Tang, Ming Wang, Shuai Zhu, Guangxu Wu, Yik-Chung Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong Shenzhen Research Institute of Big Data Shenzhen China Department of Computer Science and Engineering Southern University of Science and Technology Shenzhen China Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China

Street Scene Semantic Understanding (denoted as TriSU) is a crucial but complex task for world-wide distributed autonomous driving (AD) vehicles (e.g., Tesla). Its inference model faces poor generalization issue due to inter-city domain-shift. Hierarchical Federated Learning (HFL) offers a potential solution for improving TriSU model generalization, but suffers from slow convergence rate because of vehicles' surrounding heterogeneity across cities. Going beyond existing HFL works that have deficient capabilities in complex tasks, we propose a rapid-converged heterogeneous HFL framework (FedRC) to address the inter-city data heterogeneity and accelerate HFL model convergence rate. In our proposed FedRC framework, both single RGB image and RGB dataset are modelled as Gaussian distributions in HFL aggregation weight design. This approach not only differentiates each RGB sample instead of typically equalizing them, but also considers both data volume and statistical properties rather than simply taking data quantity into consideration. Extensive experiments on the TriSU task using across-city datasets demonstrate that FedRC converges faster than the state-of-the-art benchmark by 38.7%, 37.5%, 35.5%, and 40.6% in terms of mIoU, mPrecision, mRecall, and mF1, respectively. Furthermore, qualitative evaluations in the CARLA simulation environment confirm that the proposed FedRC framework delivers top-tier performance. © 2024, CC BY-NC-ND.

关键词： Semantics

来源：评论

学校读者我要写书评

暂无评论

Large-Scale Electromagnetic Structure for Ambient RF Energy Harvesting

Large-Scale Electromagnetic Structure for Ambient RF Energy ...

引用

Antennas and Propagation & USNC/URSI National Radio Science Meeting

作者： Charles Ng Chi-Yuk Chiu Ross Murch Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong Institute for Advanced Study The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong

ISBN: (数字)9798350369908

ISBN: (纸本)9798350369915

This research explores the integration of the Internet of Things (IoT) within a large-scale electromagnetic (EM) structure powered by innovative ambient radio frequency (RF) energy harvesting. The proposed planar Yagi antenna, designed for the GSM-900 frequency range, serves as a foundational element. Simulations reveal its efficiency, achieving a maximum gain of 5.9 dBi within the 930 to 980 MHz band. Building upon this, an 8×4 array of 32 planar Yagi antennas is devised to increase signal strength, aiming for approximately 20 dB gain. A phased-array approach with 60-degree phase shifts enhances adaptability, allowing beam tilting away from the wall. Simulations confirm a 34-degree tilt, validating the array's performance. The large-scale EM structure, with its array configuration and beamforming capabilities, presents significant promise for applications requiring heightened signal strength and adaptability. Prototyping for IoT sensor systems is underway, marking a step toward interconnected, sustainable, and intelligent environments.

关键词： Radio frequency Adaptation models Array signal processing Adaptive arrays Sensor systems Energy harvesting Structural beams

来源：评论

学校读者我要写书评

暂无评论

Fast-Convergent and Communication-Alleviated Heterogeneous Hierarchical Federated Learning in Autonomous Driving

arXiv

引用

arXiv 2024年

作者： Kou, Wei-Bin Lin, Qingfeng Tang, Ming Ye, Rongguang Wang, Shuai Zhu, Guangxu Wu, Yik-Chung The Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong Shenzhen Research Institute of Big Data Shenzhen China The Department of Computer Science and Engineering Southern University of Science and Technology Shenzhen China Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China

Street Scene Semantic Understanding (denoted as TriSU) is a complex task for autonomous driving (AD). However, inference model trained from data in a particular geographical region faces poor generalization when applied in other regions due to inter-city data domain-shift. Hierarchical Federated Learning (HFL) offers a potential solution for improving TriSU model generalization by collaborative privacy-preserving training over distributed datasets from different cities. Unfortunately, it suffers from slow convergence because data from different cities are with disparate statistical properties. Going beyond existing HFL methods, we propose a Gaussian heterogeneous HFL algorithm (FedGau) to address inter-city data heterogeneity so that convergence can be accelerated. In the proposed FedGau algorithm, both single RGB image and RGB dataset are modelled as Gaussian distributions for aggregation weight design. This approach not only differentiates each RGB image by respective statistical distribution, but also exploits the statistics of dataset from each city in addition to the conventionally considered data volume. With the proposed approach, the convergence is accelerated by 35.5%-40.6% compared to existing state-of-the-art (SOTA) HFL methods. On the other hand, to reduce the involved communication resource, we further introduce a novel performance-aware adaptive resource scheduling (AdapRS) policy. Unlike the traditional static resource scheduling policy that exchanges a fixed number of models between two adjacent aggregations, AdapRS adjusts the number of model aggregation at different levels of HFL so that unnecessary communications are minimized. Extensive experiments demonstrate that AdapRS saves 29.65% communication overhead compared to conventional static resource scheduling policy while maintaining almost the same performance. © 2024, CC BY-NC-ND.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Investigation on the dynamic damage process of HfO2/SiO2 anti-reflection coatings under 1064nm nanosecond laser irradiation

Investigation on the dynamic damage process of HfO2/SiO2 ant...

引用

Pacific-Rim Laser Damage 2023: Optical Materials for High-Power Lasers

作者： Xiang, Chengjiang Liu, Xiaofeng Tao, Chunxian Li, Dawei Zhao, Yuan’an Sun, Jian Zhang, Weili Shao, Yuchuan Shao, Jianda School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai200093 China Laboratory of Thin Film Optics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai201800 China Key Laboratory of High Power Laser Materials Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai201800 China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing100049 China Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences Hangzhou310024 China

ISBN: (纸本)9781510672826

Time-resolved pump-probe technology is an effective method to study the dynamic damage process of optics. In this paper, the dynamic damage process of HfO2/SiO2 anti-reflection coating, for the cases that the coating located on the laser incidence (forward process) and exit (reverse process) surface, irradiated by a 1064nm nanosecond laser was studied based on the time-resolved pump-probe technology of intensified charge-coupled device (ICCD). Under the irradiation of the same fluence (52J/cm2), pits without and with the layer peeling existed in both forward and reverse processes. However, the lateral size and depth of the small pits generated by the reverse process are larger than those of the forward process. The finite element analysis shows that the electric field intensity (EFI) on the substrate-coating interface for the forward and reverse processes is similar, which is not enough to form the difference in damage morphology. These results indicate the develop process of the plasma after its formation under the subsequent laser pulse irradiation determines the damage difference in the above two cases. The time-resolved study of anti-reflective coating damage is of great significance for its damage mechanism analysis and practical application. © 2023 SPIE.

关键词： Laser damage

来源：评论

学校读者我要写书评

暂无评论

Stochastic model of noise for a quantum thermal transistor

引用

Physical Review B 2023年第23期108卷 235421-235421页

作者： Uthpala N. Ekanayake Sarath D. Gunapala Malin Premaratne Advanced Computing and Simulation Laboratory (AχL) Department of Electrical and Computer Systems Engineering Monash University Clayton Victoria 3800 Australia Jet Propulsion Laboratory California Institute of Technology Pasadena California 91109 USA

Our focus in this investigation lies in developing a noise model for a quantum thermal transistor model inspired by its electronic counterpart, with the primary aim of establishing a platform for constructing analogous models. Previous studies on coupled two-level systems-based thermal transistors were focused on their average energy exchange. In this paper, we shift our attention to exploring the stochastic behavior of such thermal transistors due to the disturbances caused to their environment, such as continuous measurements. In the literature, the master equation for the transistor model is derived using the reduced dynamics method. This way, it masks the study of the stochastic nature of the energy flows in the system due to disturbances to the environment. In this paper, we describe a quantum trajectory under measurement theory whose ensemble average unravels the master equation for a quantum thermal transistor. This allows us to analyze the fluctuations and noise levels in the transistor model with greater detail. Then, we produce a numerical solution for the transistor dynamics based on Euler-Maruyama approximation. This helps to establish a model for the thermal transistor, drawing parallels to the small-signal/noise model in an electronic transistor. We define two parameters, thermal conductance and output thermal resistance, to describe the small signal-like model for the thermal transistor. Through these investigations, we seek to gain insights that can help design advanced heat management devices at the quantum level.

关键词： Open quantum systems Quantum gates Thermal properties Nanotechnology Transistors

来源：评论

学校读者我要写书评

暂无评论

An Iterative Method for a Frequency Domain PID Controller Synthesis

An Iterative Method for a Frequency Domain PID Controller Sy...

引用

SICE Annual Conference

作者： Kenjiro Minamikawa Yasushi Kami Eitaku Nobuyama Atsushi Hosokawa Department of Mechanical and Electronic System Engineering Advanced Course of National Institute of Technology Akashi College Hyogo Japan Department of Electrical Systems Engineering Hiroshima Institute of Technology Hiroshima Japan Department of Intelligent and Control Systems Kyushu Institute of Technology Fukuoka Japan Department of Electrical and Computer Engineering National Institute of Technology Akashi College Hyogo Japan

This study is concerned with a control system design method with frequency response data named a finite number of frequency responses(an FNFR) model. In this paper a numerical descent direction is introduced and an iterative method for solving control problems formulated with the FNFR model is proposed with the descent direction. One feature of our approach is to update controller variables so that they approach to a feasible region of considering control problems from the outside. The efficiency of our method is shown by numerical examples.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Amplified Cooling of Light via Emergent Onsager Irreversible Thermodynamics

Amplified Cooling of Light via Emergent Onsager Irreversible...

引用

CLEO: Fundamental Science, CLEO:FS 2024 - Part of Conference on Lasers and Electro-Optics, CLEO 2024

作者： Xiong, Zhongfei Wu, Fan O. Liu, Yang Jiang, Jian-Hua Christodoulides, Demetrios N. Chen, Yuntian School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan430074 China School of Applied and Engineering Physics Cornell University IthacaNY14853 United States Ming Hsieh Department of Electrical and Computer School of Physical Science and Technology Soochow University Suzhou215006 China Suzhou Institute for Advanced Research University of Science and Technology of China Suzhou215123 China Department of Electrical Engineering University of Southern California Los AngelesCA90089 United States Wuhan National Laboratory of Optoelectronics Huazhong University of Science and Technology Wuhan430074 China

While conventional cooling schemes solely depend on temperature differences, here we demonstrate that in photonics configurations, amplified cooling can be achieved by judiciously manipulating Onsager coefficients thr... 详细信息

ISBN: (纸本)9781957171395

关键词： Photonics

来源：评论

学校读者我要写书评

暂无评论

Nanophotonic neural probe enabled light-sheet light-field fluorescence imaging microendoscope

Nanophotonic neural probe enabled light-sheet light-field fl...

引用

Conference on Lasers and Electro-Optics (CLEO)

作者： Peisheng Ding Hannes Wahn Fu-Der Chen Xianshu Luo Guo-Qiang Lo Joyce K. S. Poon Wesley D. Sacher Max Planck Institute of Microstructure Physics Halle Germany Department of Electrical and Computer Engineering University of Toronto Toronto Ontario Canada Advanced Micro Foundry Pte Ltd Singapore

We demonstrate a lensless volumetric imaging microendoscope for deep-brain fluorescence microscopy. It consists of a nanophotonic neural probe for light-sheet illumination and an image fiber bundle for light-field flu... 详细信息

ISBN: (纸本)9781957171258

关键词： Fiber bundles Fiber coatings Fluorescence microscopy Image quality Multicore fibers Plenoptic imaging

来源：评论

学校读者我要写书评

暂无评论

Hybrid surface waves in twisted anisotropic heterometasurfaces

引用

Physical Review Applied 2024年第6期21卷 064034-064034页

作者： Xinyan Zhang Chenxu Bian Zheng Gong Ruoxi Chen Tony Low Hongsheng Chen Xiao Lin Interdisciplinary Center for Quantum Information State Key Laboratory of Extreme Photonics and Instrumentation International Joint Innovation Center The Electromagnetics Academy at Zhejiang University Department of Electrical and Computer Engineering Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang Jinhua Institute of Zhejiang University Shaoxing Institute of Zhejiang University

Recent advances in twisted photonic structures (e.g., twisted bilayer graphene and twisted anisotropic metasurfaces) have enabled many exotic phenomena of light-matter interactions, such as topological transition of the isofrequency contour of surface waves at the magic angle, photonic flatbands, and localization-to-delocalization transition of light. In general, the optical features of these twisted photonic structures are sensitive to the interlayer twist angle. Here we investigate the mode hybridization of surface waves supported by twisted bilayer anisotropic heterometasurfaces, whose two constituent metasurfaces are nonidentical and support surface waves with similar spatial confinements but distinct polarizations. Counterintuitively, we find that the shape of the isofrequency contour of these hybrid surface waves—eigenmodes with both transverse magnetic and transverse electric wave components—can be insensitive to the twist angle, due to the weak interlayer electromagnetic coupling. Moreover, the interlayer distance provides a unique route to reshape the dispersion of one specific kind of hybrid surface wave, while it has negligible influence on the other kinds. Our finding enriches the physics of light-matter interactions in twisted photonic structures and may open new possibilities to mold the flow of light at the subwavelength scale.

关键词： Classical optics Light-matter interaction Metamaterials Metasurfaces Near-field optics Photonics Plasmonics Van der Waals interaction

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：