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Asia Communications and Photonics Conference and Exhibition (ACP)

作者： Suwan Qin Xiongfeng Rao Li Yang Department of Electronic Engineering and Information Science University of Science and Technology of China Key Laboratory of Electromagnetic Space Information Chinese Academy of Science Hefei China

We propose an angular symmetry fiber and demon-strate its capability for the transmission of optical orbital angular momentum modes by using numerical analysis based on finite element method.

ISBN: (数字)9798350379266

ISBN: (纸本)9798350379273

We propose an angular symmetry fiber and demon-strate its capability for the transmission of optical orbital angular momentum modes by using numerical analysis based on finite element method.

关键词： Optical fibers Orbital calculations Perturbation methods Stability criteria Refractive index Optical variables control Optical fiber communication Orbits Optical refraction Photonics

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Two-stage self-supervised training vision transformers for small datasets 4

Two-stage self-supervised training vision transformers for s...

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4th International Conference on Computer Vision and Pattern Analysis, ICCPA 2024

作者： Yang, Jiaxian Cai, Taiwei Chen, Haojie School of Information Science and Engineering Yunnan University Yunnan Kunming650504 China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology Institute of Electronic Paper Displays South China Academy of Advanced Optoelectronics South China Normal University Guangzhou10587 China

ISBN: (纸本)9781510682528

After a series of achievements in the field of natural language processing, Transformers have shown promising results upon their introduction to computer vision, particularly under conditions of large-scale data. However, when faced with insufficient data, the performance of Vision Transformers(ViT) often falls short compared to Convolutional Neural Networks (CNNs), which are capable of capturing intrinsic biases in the data. In this paper, to address the performance disadvantage of ViT on small datasets, we propose a two-stage self-supervised training strategy. We enhance the ViT model by introducing Sequential Overlapping Patch Embedding (SOPE) and Improved Dynamic Aggregation Feed Forward (IDAFF) modules. Applying our approach to both single-block and multi-block ViT models on five commonly used small datasets (CIFAR10, CIFAR100, CINIC10, SVHN, Tiny-ImageNet) shows the efficacy of our approach. It narrows the performance difference between ViT and CNNs during training on small datasets from the ground up, and in some cases, even achieves better classification performance than CNNs. Our codes are available at: https://***/newer7/vosd. © 2024 SPIE.

关键词： Self-supervised learning

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Local density of optical states calculated by the mode spectrum in stratified media

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Chinese Physics B 2023年第4期32卷 135-141页

作者：傅廷陈静瑄王学友戴迎秋周旭彦王宇飞王明金郑婉华 Laboratory of Solid State Optoelectronics Information Technology Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China College of Future Technology University of Chinese Academy of SciencesBeijing 101408China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Weifang Academy of Advanced Opto-electronic Circuits Weifang 261021China

The local density of optical states(LDOS)is an important physical concept,which can characterize the spontaneous emission of *** order to calculate the LDOS,the relationship between the mode spectrum and the LDOS is ***,based on the transfer matrix method and the effective resonator model,the leaky loss of the leaky mode and the mode spectrum in the one-dimensional photonic bandgap crystal waveguide are calculated,results of which indicate that the mode spectrum can characterize the leaky loss of the leaky *** last,the density of optical states(DOS),and the LDOS in each layer are *** partial DOS and the partial LDOS in the quantum well,related to the fundamental leaky mode,can be used to find out the optimal location of the quantum well in the defect layer to couple more useful photons into the lasing mode for lasers.

关键词： local density of optical states mode spectrum transfer matrix method

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Multi-View Landmark-Assisted UAV Swarm 6-DoF Pose Estimation Using Resonant Beam and VIO

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IEEE Internet of Things Journal 2025年

作者： Du, Siyuan Xu, Mengyuan Li, Yixuan Fang, Wen Liu, Qingwen Yi, Peng Hong, Yiguang Tongji University School of Computer Science and Technology Shanghai201804 China Tongji University College of Electronic and Information Engineering Shanghai201804 China Chinese Academy of Sciences Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Beijing100190 China

As an essential aerial platform in Internet of Things (IoT) applications, UAV swarms require high-precision attitude estimation in GPS-limited and dynamic environments, which supports higher-level IoT functions such as smart logistics, disaster response, and environmental monitoring. However, most odometry-based pose estimation methods in dynamic scenarios without GPS encounter issues with cumulative errors over time. In this paper, we propose a method to reduce these cumulative errors by constraining the absolute positioning of Visual-Inertial Odometry (VIO) using relative poses obtained from multi-view landmark and Resonant-Beam (RBeam) sensors between UAVs. For synchronous moments, we estimate the 6 Degree-of-Freedom (DoF) relative pose using the Angle of Arrival and Time of Flight data from the RBeam, combined with nonlinear optimization. For asynchronous moments, a two-stage visual estimation method is introduced, combining multi-camera epipolar geometry for rotation recovery and depth reconstruction optimization for translation recovery, enabling the estimation of asynchronous relative poses. Finally, we design a global objective function based on a sliding window and factor graph, integrating RBeam, multi-view landmark, and VIO for absolute 6-DoF pose optimization of the UAV swarm. Simulation results demonstrate that optimizing with the addition of RBeam synchronous relative poses improves overall positioning accuracy by 32.94% compared to pure VIO. Incorporating both RBeam synchronous and visual asynchronous relative poses further enhances overall positioning accuracy by 37.65%. Additionally, the UAV’s attitude benefits from the rotational constraints provided by the RBeam, achieving over 30% improvement in the pitch and yaw directions. © 2014 IEEE.

关键词： Global positioning system

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Realizing submeter spatial resolution for Raman distributed fiber-optic sensing using a chaotic asymmetric paired-pulse correlation-enhanced scheme

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Photonics Research 2024年第10期12卷 2365-2375页

作者： BOWEN FAN JIAN LI ZIJIA CHENG XIAOHUI XUE MINGJIANG ZHANG College of Electronic Information and Optical Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Advanced Transducers and Intelligent Control Systems(Ministry of Education and Shanxi Province) Taiyuan University of TechnologyTaiyuan 030024China College of Physics Taiyuan University of TechnologyTaiyuan 030024China

The sensing spatial resolution and signal-to-noise ratio(SNR)of Raman distributed optical fiber sensors are limited by the pulse width and weak Raman scattering ***,the sensing spatial resolution cannot exceed the order of meters at several kilometers sensing *** break through this physical bottleneck,a novel,to our knowledge,Raman scattering model based on paired-pulse sensing is *** fundamental origins of the observed limited spatial resolution of conventional schemes are analyzed,and a chaotic asymmetric paired-pulse correlation-enhanced scheme for Raman distributed fiber-optic sensing is proposed and experimentally *** proposed scheme uses a chaotic asymmetric paired-pulse as the sensing signal and extracts the light intensity information of each data point of the sensing fiber,which carries the random undulation characteristics of chaotic time series,based on the time-domain differential reconstruction *** scheme overcomes the pulse width limitation of spatial resolution via correlation and demodulation,enhances the correlation characteristics between the temperature-modulated Raman scattered light field and detection signal,and improves the ***,a sensing performance of 10 km,a spatial resolution of 30 cm,and an SNR of 6.67 dB are realized in the *** scheme provides a new research idea for a high-performance Raman distributed optical fiber sensing system.

关键词： fiber pulse scattering

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Hybrid Seasonal Prediction of Meridional Temperature Gradient Associated with“Warm Arctic-Cold Eurasia”

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Advances in Atmospheric sciences 2023年第9期40卷 1649-1661页

作者： Tianbao XU Zhicong YIN Xiaoqing MA Yanyan HUANG Huijun WANG Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

The meridional gradient of surface air temperature associated with“Warm Arctic–Cold Eurasia”(GradTAE)is closely related to climate anomalies and weather extremes in the mid-low ***,the Climate Forecast System Version 2(CFSv2)shows poor capability for GradTAE *** on the year-to-year increment approach,analysis using a hybrid seasonal prediction model for GradTAE in winter(HMAE)is conducted with observed September sea ice over the Barents–Kara Sea,October sea surface temperature over the North Atlantic,September soil moisture in southern North America,and CFSv2 forecasted winter sea ice over the Baffin Bay,Davis Strait,and Labrador *** demonstrates good capability for predicting GradTAE with a significant correlation coefficient of 0.84,and the percentage of the same sign is 88%in cross-validation during 1983−*** also maintains high accuracy and robustness during independent predictions of 2016−***,HMAE can predict the GradTAE in 2021 well as an experiment of routine ***,well-predicted GradTAE is useful in the prediction of the large-scale pattern of“Warm Arctic–Cold Eurasia”and has potential to enhance the skill of surface air temperature occurrences in the east of China.

关键词： warm Arctic-cold Eurasia year-to-year increment climate prediction sea ice SST

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Size-Invariance Matters: Rethinking Metrics and Losses for Imbalanced Multi-object Salient Object Detection 41

Size-Invariance Matters: Rethinking Metrics and Losses for I...

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41st International Conference on Machine Learning, ICML 2024

作者： Li, Feiran Xu, Qianqian Bao, Shilong Yang, Zhiyong Cong, Runmin Cao, Xiaochun Huang, Qingming Institute of Information Engineering Chinese Academy of Sciences Beijing China School of Cyber Security University of Chinese Academy of Sciences Beijing China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing China School of Computer Science and Technology University of Chinese Academy of Sciences Beijing China Institute of Information Science Beijing Jiaotong University Beijing China School of Control Science and Engineering Shandong University Jinan China Key Laboratory of Machine Intelligence and System Control Ministry of Education Jinan China School of Cyber Science and Tech. Sun Yat-sen University Shenzhen Campus China Key Laboratory of Big Data Mining and Knowledge Management Chinese Academy of Sciences Beijing China

This paper explores the size-invariance of evaluation metrics in Salient Object Detection (SOD), especially when multiple targets of diverse sizes co-exist in the same image. We observe that current metrics are size-sensitive, where larger objects are focused, and smaller ones tend to be ignored. We argue that the evaluation should be size-invariant because bias based on size is unjustified without additional semantic information. In pursuit of this, we propose a generic approach that evaluates each salient object separately and then combines the results, effectively alleviating the imbalance. We further develop an optimization framework tailored to this goal, achieving considerable improvements in detecting objects of different sizes. Theoretically, we provide evidence supporting the validity of our new metrics and present the generalization analysis of SOD. Extensive experiments demonstrate the effectiveness of our method. The code is available at https://***/Ferry-Li/SI-SOD. Copyright 2024 by the author(s)

关键词： Object detection

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Small moving target interference suppression detection method in space-time Doppler frequency shift domain

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Chinese Journal of Acoustics 2023年第1期42卷 1-21页

作者： SUN Dajun HOU Kaiyang TENG Tingting MEI Jidan LIU Huimin LI Yecheng Acoustic Science and Technology Laboratory Harbin Engineering UniversityHarbin 150001 Key Laboratory of Marine Information Acquisition and Security(Harbin Engineering University) Ministry of Industry and Information TechnologyHarbin 150001 College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001 East China Research Institute of Electronic Engineering Hefei 230088 The 54thResearch Institute of China Electronics Technology Group Corporation Shijiazhuang 050081

Active sonar can separate clutter,reverberation,and moving targets in the Doppler frequency shift domain using Doppler sensitive signals,but time and Doppler leakages of strong interference can inundate weak targets at low signal-to-interference ***,a small moving target interference suppression detection method based on an adaptive least mean square(LMS)algorithm and wide-band ambiguity function(WAF)is ***,an adaptive notch filter based on LMS is used to suppress interference in the spatial Doppler frequency shift domain and then WAF used to detect targets in the fast-time Doppler frequency shift *** simulation and pool experiments are performed and the results demonstrated that the proposed method effectively suppress strong interference and accurately estimate the target delay and Doppler *** 13 dB of interference suppression is observed in *** addition,the system is able to tolerate interference fluctuations with normalized amplitude fluctuation variance less than 0.5 and improve the active detection capacity for small moving targets.

关键词： Small moving method

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A New Approach to Functional Zoning of Wetlands in Coastal Urban Agglomerations and Its Application in Two Coastal Urban Agglomerations, China

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Chinese Geographical science 2025年

作者： ZHANG Ze JIANG Weiguo LING Ziyan WU Zhengfang PENG Kaifeng State Key Laboratory of Remote Sensing and Digital Earth Faculty of Geographical Science Beijing Normal University Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities Faculty of Geographical ScienceBeijing Normal University School of Information and Control Engineering Qingdao University of Technology School of Geography and Remote Sensing Guangzhou University College of Geographic and Environmental Sciences Tianjin Normal University

Wetlands offer important ecological functions and *** functional zoning provides a reference and basis for sustainable fulfilment and *** this study,two coastal urban agglomerations in South China were taken as study areas,namely,the Guangxi Beibu Gulf (GBG) and Guangdong-Hong Kong-Macao Greater Bay Area (GBA).Based on multisource information data,a wetland functional zoning system was constructed with the four levels of zoning concept,zoning principle,zoning basis,and zoning *** functional zoning and dynamic analysis of wetlands from 1990 to 2020 were carried out from multiple perspectives of wetland ecological functions,wetland management and conservation *** results showed that:1) in terms of wetland ecological functions,the two coastal urban agglomerations were dominated by hydrological regulation and purification of environmental functional *** coastal region was largely characterized by the main functional areas of climate regulation and biodiversity maintenance.2) Regarding wetland management and conservation functions,two coastal urban agglomerations exhibited similar trends in terms of the sizes of their conservation and buffer zones from 1990 to *** and control zones were mainly located in core cities in a concentrated *** zones largely comprised mountainous woodlands and important wetlands.3) The two coastal urban agglomerations could be divided into 21 wetland functional *** central river area has remained the main prevention and control zone for many *** conservation zones,ecological protection and restoration should be the main *** buffer zones,the construction of wetlands and surrounding complex systems should be strengthened or *** prevention and control zones,activities that do not affect wetland functions should be allowed,provided that they comply with existing laws and *** study could provide technical support and prac

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A discrete moth-flame optimization algorithm for multiple automated guided vehicles scheduling problem in a matrix manufacturing workshop

A discrete moth-flame optimization algorithm for multiple au...

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作者： Zeng, Junhai Xie, Wei Pan, Mi School of Automation Science and Engineering South China University of Technology Guangdong Guangzhou510641 China Key Laboratory of Autonomous Systems and Networked Control Ministry of Education South China University of Technology Guangdong Guangzhou510641 China Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing South China University of Technology Guangdong Guangzhou510641 China Department of Civil and Environmental Engineering University of Macau 999078 China

The growing need for customized and varied production has highlighted the significance of smart and automated factories in the manufacturing sector. In this particular context, the scheduling of multiple Automated Guided Vehicles (AGVs) plays a pivotal role in enhancing the efficiency of operations within an intelligent manufacturing shop. This study centers on the material handling process within a matrix manufacturing shop with the objective of identifying the most cost-effective transportation routes for materials. To accomplish the specified objective, this research aims to identify an optimal solution for reducing transportation costs. In particular, this study formulates a mixed-integer linear programming model and introduces a novel discrete variant of the moth-flame optimization (MFO) algorithm, named DMFO, to address the scheduling problem. The DMFO algorithm incorporates several significant enhancements. Firstly, a population initialization method is proposed, which combines a nearest-neighbor-based adaptive heuristic and a random sorting technique to ensure the formation of a well-structured population. Secondly, the flame generation mechanism and spiral flight search processes within the MFO have been redefined to achieve a more optimal balance between exploration and exploitation. A neighborhood search mechanism is subsequently devised, employing the concept of neighborhood relevance to accelerate the convergence process. Additionally, a heuristic approach is introduced to reduce the computational cost. Moreover, a population regeneration mechanism is proposed to avoid the algorithm falling into a local optimum. To validate the effectiveness of the DMFO, a comparative analysis is conducted using a dataset of 110 real-world factory instances. In this analysis, eight well-established optimization algorithms are employed. The simulation results consistently demonstrate that the relative percentage deviation (RPD) value of the DMFO tends to approach 0% more

关键词： Materials handling

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