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Inverse design of highly efficient and broadband mode splitter on SOI platform

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Chinese Optics Letters 2024年第1期22卷 59-64页

作者：廖俊鹏田野杨子荣徐豪达唐晨王钰恒张晓伟康哲 department of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China Centre for Optical and electromagnetic Research College of Optical Science and EngineeringZhejiang UniversityHangzhou 310058China

Mode splitters that directly separate modes without changing their orders are highly promising to improve the flexibility of the mode-division multiplexing *** this paper,we design a high-performance mode splitter on the silicon-oninsulator platform with a compact footprint of 14μm×2.5μm using an inverse design method based on shape *** fabrication of this mode splitter requires only a single lithography step and exhibits good fabrication *** experimental results show that the proposed device exhibits state-of-the-art insertion loss(<0.9 dB)and cross talk(<-16 dB)over a broad bandwidth(1500-1600 nm).Furthermore,the shape optimization method used is implemented to design a dual-mode(de)multiplexer,and the experimental results fulfill the design objective,demonstrating the excellent generality of the design method in this paper.

关键词： integrated optics inverse design mode splitter

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Improved organs at risk segmentation based on modified U‐Net with self‐attention and consistency regularisation

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CAAI Transactions on Intelligence Technology 2024年第4期9卷 850-865页

作者： Maksym Manko Anton Popov Juan Manuel Gorriz Javier Ramirez Electronic Engineering department Igor Sikorsky Kyiv Polytechnic InstituteKyivUkraine department of Signal theory Telematics and CommunicationsUniversity of GranadaGranadaSpain

Cancer is one of the leading causes of death in the world,with radiotherapy as one of the treatment *** planning starts with delineating the affected area from healthy organs,called organs at risk(OAR).A new approach to automatic OAR seg-mentation in the chest cavity in Computed Tomography(CT)images is *** proposed approach is based on the modified U‐Net architecture with the ResNet‐34 encoder,which is the baseline adopted in this *** new two‐branch CS‐SA U‐Net architecture is proposed,which consists of two parallel U‐Net models in which self‐attention blocks with cosine similarity as query‐key similarity function(CS‐SA)blocks are inserted between the encoder and decoder,which enabled the use of con-sistency *** proposed solution demonstrates state‐of‐the‐art performance for the problem of OAR segmentation in CT images on the publicly available SegTHOR benchmark dataset in terms of a Dice coefficient(oesophagus-0.8714,heart-0.9516,trachea-0.9286,aorta-0.9510)and Hausdorff distance(oesophagus-0.2541,heart-0.1514,trachea-0.1722,aorta-0.1114)and significantly outperforms the *** current approach is demonstrated to be viable for improving the quality of OAR segmentation for radiotherapy planning.

关键词： 3‐D computer vision deep learning deep neural networks image segmentation medical image processing object segmentation

Flexible 2 × 2 multiple access visible light communication system based on an integrated parallel GaN/InGaN micro-photodetector array module

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Photonics Research 2024年第4期12卷 793-803页

作者： ZENGYI XU XIANHAO LIN ZHITENG LUO QIANYING LIN JIANLI ZHANG GUANGXU WANG XIAOLAN WANG FENGYI JIANG ZIWEI LI JIANYANG SHI JUNWEN ZHANG CHAO SHEN NAN CHI Key Laboratory for Information Science of electromagnetic Waves(MoE) Department of Communication Science and EngineeringFudan UniversityShanghai 200433China National Institute of LED on Silicon Substrate Nanchang UniversityNanchang 330096China

In recent studies, visible light communication(VLC) has been predicted to be a prospective technique in the future 6G communication systems. To suit the trend of exponentially growing connectivity, researchers have intensively studied techniques that enable multiple access(MA) in VLC systems, such as the MIMO system based on LED devices to support potential applications in the Internet of Things(IoT) or edge computing in the nextgeneration access network. However, their transmission rate is limited due to the intrinsic bandwidth of ***, the majority of visible light laser communication (VLLC) research with beyond 10 Gb/s data rates concentrates on point-to-point links, or using discrete photodetector(PD) devices instead of an integrated array PD. In this paper, we demonstrated an integrated PD array device fabricated with a Si-substrated GaN/InGaN multiple-quantum-well(MQW) structure, which has a 4 × 4 array of 50 μm × 50 μm micro-PD units with a common cathode and anode. This single-integrated array successfully provides access for two different transmitters simultaneously in the experiment, implementing a 2 × 2 MIMO-VLLC link at 405 nm. The highest data rate achieved is 13.2 Gb/s, and the corresponding net data rate(NDR) achieved is 12.27 Gb/s after deducing the FEC overhead, using 2.2 GHz bandwidth and superposed PAM signals. Furthermore, we assess the Huffman-coded coding scheme, which brings a fine-grain adjustment in access capacity and enhances the overall data throughput when the user signal power varies drastically due to distance, weather, or other challenges in the channel condition. As far as we know, this is the first demonstration of multiple visible light laser source access based on a single integrated GaN/InGaN receiver module.

关键词： communication visible light

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Macroscopic model and statistical model to characterize electromagnetic information of a digital coding metasurface

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National Science Review 2024年第3期11卷 159-171页

作者： Rui Wen Shao Jun Wei Wu Zheng Xing Wang Hui Xu Han Qing Yang Qiang Cheng Tie Jun Cui Institute of electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University Peng Cheng Laboratory Pazhou Laboratory(Huangpu)

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

关键词： electromagnetic information theory current entropy current space digital coding metasurface macroscopic model statistical model

A Dynamic Network Game of the Fintech Industry

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Journal of the Operations Research Society of China 2024年第1期12卷 5-33页

作者： David W.K.Yeung Leon A.Petrosyan Ying-Xuan Zhang SRS Consortium for Advanced Study in Cooperative Dynamic Games Shue Yan UniversityHong KongChina Center of Game theory St Petersburg State UniversitySaint PetersburgRussia department of Finance Asia UniversityTaichung CityTaiwanChina Faculty of Applied Mathematics-Control Processes and Center of Game theory St Petersburg StateUniversitySaint PetersburgRussia

Economies of scale,economies of scope,and technology spillover are decisive eco-nomic elements that are crucial to the development in the Fintech *** externalities are often realized through network *** this paper,we presenta dynamic network ofﬁnancialﬁrms which exhibits these decisive *** game equilibria are characterized.A Pareto efﬁcient solution involving col-laboration of allﬁrms is *** obtain a fair-share distribution of cooperativegains,the Shapley value is adopted as the sharing *** distributionmechanisms which guarantee the fulﬁlment of the Shapley value distribution in eachstage of the cooperation duration are derived.

关键词： Network game Network equilibria Shapley value Pareto efﬁcientcooperation

An Elastoplastic Fracture Model Based on Bond-Based Peridynamics

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2349-2371页

作者： Liping Zu Yaxun Liu Haoran Zhang Lisheng Liu Xin Lai Hai Mei department of Engineering Structure and Mechanics Wuhan University of TechnologyWuhan430070China Hubei Key Laboratory of theory and Application of Advanced Materials Mechanics Wuhan University of TechnologyWuhan430070China

Fracture in ductile materials often occurs in conjunction with plastic ***,in the bond-based peridynamic(BB-PD)theory,the classic mechanical stress is not defined *** makes it difficult to describe plasticity directly using the classical plastic *** address the above issue,a unified bond-based peridynamics model was proposed as an effective tool to solve elastoplastic fracture *** to the existing models,the proposed model directly describes the elastoplastic theory at the bond level without the need for additional calculation *** results obtained in the context of this model are shown to be consistent with FEM results in regard to force-displacement curves,displacement fields,stress fields,and plastic deformation *** model exhibits good capability of capturing crack propagation in ductile material failure problems.

关键词： Ductile materials plastic deformation bond-based peridynamics isotropic hardening fracture analysis

Robustness Assessment of Wind Power Generation Considering Rigorous Security Constraints for Power System: A Hybrid RLO-IGDT Approach

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 518-529页

作者： Lianyong Zuo Shengshi Wang Yong Sun Shichang Cui Jiakun Fang Xiaomeng Ai Baoju Li Chengliang Hao Jinyu Wen State Key Laboratory of Advanced electromagnetic Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430073China State Grid Jilin Electric Power Company Changchun 130021China

Fossil fuel depletion and environmental pollution problems promote development of renewable energy(RE)*** increasing penetration of RE,operation security and economy of power systems(PS)are greatly impacted by fluctuation and intermittence of renewable *** this paper,information gap decision theory(IGDT)is adapted to handle uncertainty of wind power *** on conventional IGDT method,linear regulation strategy(LRS)and robust linear optimization(RLO)method are integrated to reformulate the model for rigorously considering security *** a robustness assessment method based on hybrid RLO-IGDT approach is proposed for analyzing robustness and economic performance of ***,a risk-averse linearization method is adapted to convert the proposed assessment model into a mixed integer linear programming(MILP)problem for convenient optimization without robustness ***,results of case studies validate superiority of proposed method in guaranteeing operation security rigorously and effectiveness in assessment of RSR for PS without *** Terms-Hybrid RLO-IGDT approach,information gap decision theory(IGDT),operation security,robustness assessment,robustness security region(RSR).

关键词： IGDT approach information gap decision theory(IGDT) operation security robustness assessment robustness security region(RSR)

Sampling-efficient path planning and improved actor-critic-based obstacle avoidance for autonomous robots

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Science China(Information Sciences) 2024年第5期67卷 197-214页

作者： Yefeng YANG Tao HUANG Tianqi WANG Wenyu YANG Han CHEN Boyang LI Chih-yung WEN department of Aeronautical and Aviation Engineering The Hong Kong Polytechnic University Center for Control theory and Guidance Technology Harbin Institute of Technology School of Engineering The University of Newcastle Research Center for Unmanned Autonomous Systems The Hong Kong Polytechnic University

Autonomous robots have garnered extensive utilization in diverse fields. Among the critical concerns for autonomous systems, path planning holds paramount importance. Notwithstanding considerable efforts in its development over the years, path planning for autonomous systems continues to grapple with challenges related to low planning efficiency and inadequate obstacle avoidance response in a timely *** study proposes a novel and systematic solution to the path planning problem within intricate office buildings. The solution consists of a global planner and a local planner. To handle the global planning aspect, an adaptive clustering-based dynamic programming rapidly exploring random tree(ACDP-RRT) algorithm is proposed. ACDP-RRT effectively identifies obstacles on the map by leveraging geometric *** obstacles are then represented as a collection of sequentially arranged convex polygons, optimizing the sampling region and significantly enhancing sampling efficiency. For local planning, a network decoupling actor-critic(ND-AC) algorithm is employed. The proposed ND-AC simplifies the local planner design process by integrating planning and control loops into a neural network(NN) trained via an end-to-end model-free deep reinforcement learning(DRL) framework. Moreover, the adoption of network decoupling(ND) techniques leads to an improved obstacle avoidance success rate when compared to conventional actor-critic(AC)-based methods. Extensive simulations and experiments are conducted to demonstrate the effectiveness and robustness of the proposed approach.

关键词： rapidly exploring random tree (RRT) adaptive clustering network decoupling actor critic (AC) path planning

Impact Performance Research of Re-Entrant Octagonal Negative Poisson’s Ratio Honeycomb with Gradient Design

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 3105-3119页

作者： Yiyuan Li Yongjing Li Shilin Yan Pin Wen department of Engineering Structure and Mechanics Wuhan University of TechnologyWuhan430070China Hubei Key Laboratory of theory and Application of Advanced Materials Mechanics School of ScienceWuhan University of TechnologyWuhan430070China

Based on the traditional re-entrant honeycomb,a novel re-entrant octagon honeycomb(ROH)is *** deformation mode of the honeycomb under quasi-static compression is analyzed by numerical simulation,and the results are in good agreement with the experimental *** deformation modes,mechanical properties,and energy absorption characteristics of ROH along the impact and perpendicular directions gradient design are investigated under different *** results indicated that the deformation mode of ROH is affected by gradient design along the direction of impact and impact *** addition,gradient design along the direction of impact can increase the initial peak stress of ROH and accelerate its densification *** design perpendicular to the impact direction can enhance the energy absorption performance of ROH,especially for ROH,with wall thickness increasing from the inside *** to ROH with uniform wall thickness at the same relative density,ROH with a gradient design can increase the plateau stress by over *** the elevation of impact velocity,the plateau stress and specific energy absorption exhibit an upward trend,aligning with the dynamic performance pattern observed in conventional *** results can be used as a reference for the design and application of honeycomb and provide a new idea for developing more efficient and reliable energy-absorbing materials.

关键词： Re-entrant honeycomb gradient design finite element analysis additive manufacturing technologies