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Estimating and enlarging the region of attraction of multi-equilibrium points system by state-dependent edge impulses

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nonlinear DYNAMICS 2021年第3期103卷 2421-2436页

作者： Li, Yi Li, Chuandong He, Zhilong Shen, Zixiang Southwest Univ Chongqing Key Lab Nonlinear Circuits & Intelligen Chongqing 400715 Peoples R China Southwest Univ Coll Elect & Informat Engn Chongqing 400715 Peoples R China

When an isolated equilibrium of a nonlinear system is locally attractive, it might be difficult to estimate and then enlarge its Region of Attraction (RA). To solve this problem, this paper, by means of impulsive control, provides an effective method, i.e., state-dependent edge impulse (STDEI) combining with SOS programming and trajectory reversing with convex hull. Based on SOS programming and trajectory reversing, the initial estimation of RA is established. Then, by applying STDEI, we can design and then obtain the enlarged estimation of RA. Three numerical examples are provided to demonstrate the performance of the proposed approaches.

关键词： State-dependent impulse control State-dependent edge impulse method (STDEI) Target point Region of attraction Sum-of-squares (SOS) programming Trajectory reversing

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The role of oxygen vacancies in Ga2O3-based solar-blind photodetectors

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JOURNAL OF ALLOYS AND COMPOUNDS 2024年 970卷

作者： Wang, Jinjin Ji, Xueqiang Yan, Zuyong Qi, Song Liu, Xue Zhong, Aoxue Li, Peigang Beijing Univ Posts & Telecommun Sch Integrated Circuits Beijing 100876 Peoples R China Beijing Univ Posts & Telecommun State Key Lab Informat Photon & Opt Commun Beijing 100876 Peoples R China Lanzhou Univ Technol Sch Sci Lanzhou 730050 Peoples R China Anhui Univ Inst Phys Sci & Informat Technol Sch Mat Sci & Engn Informat Mat & Intelligent Sensing Lab Anhui Prov Hefei 230601 Peoples R China

Gallium oxide (Ga2O3) with an ultrawide bandgap, is a promising and inherent material for solar-blind photodetectors (SBPDs). However, it remains a challenge to achieve a photodetector with large responsivity and fast response speed owing to the presence of intrinsic oxygen vacancies (VO) in the Ga2O3 films. Here, the annealing and doping engineering is proposed to break the compromise between the responsivity and response speed, based on the low-cost method for annealing nitrogen-doped Ga2O3 films with various concentrations of VO in Ar, O2, and N2 atmospheres. The mechanism of regulating VO in the nitrogen-doped Ga2O3 films under various annealing atmospheres has been clarified first. The influence of concentrations of VO in pristine films and annealing atmospheres on the photoelectric properties of annealed films was analyzed systematically. The nitrogen-doping, recrystallization, and the appropriate concentration of VO in pristine Ga2O3 films are favorable factors for optimizing the properties of the post-annealing Ga2O3 films. The photodetectors based on annealing and doping engineering exhibit impressive characteristics with high photo-to-dark current ratios (PDCRs) of 2.6 x 107, large rejection ratio of R254 /R365 = 1.0 x 106, especially the faster response speed of 0.359/0.110 s, 9.8 times higher R254, and 6.34 x 102 times lower Idark than pristine films. The regulation of VO via doping and annealing methods can provide an effective strategy for low-cost high-performance Ga2O3-based SBPDs.

关键词： Solar-blind photodetectors Nitrogen-doping Annealing engineering Oxygen vacancies

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A metaheuristic-based framework for index tracking with practical constraints

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COMPLEX & intelligent SYSTEMS 2022年第6期8卷 4571-4586页

作者： Yuen, Man-Chung Ng, Sin-Chun Leung, Man-Fai Che, Hangjun Hong Kong Metropolitan Univ Sch Sci & Technol Kowloon Hong Kong Peoples R China Anglia Ruskin Univ Sch Comp & Informat Sci Cambridge England Southwest Univ Coll Elect & Informat Engn Chongqing Key Lab Nonlinear Circuits & Intelligen Chongqing Peoples R China

Recently, numerous investors have shifted from active strategies to passive strategies because the passive strategy approach affords stable returns over the long term. Index tracking is a popular passive strategy. Over the preceding year, most researchers handled this problem via a two-step procedure. However, such a method is a suboptimal global-local optimization technique that frequently results in uncertainty and poor performance. This paper introduces a framework to address the comprehensive index tracking problem (IPT) with a joint approach based on metaheuristics. The purpose of this approach is to globally optimize this problem, where optimization is measured by the tracking error and excess return. Sparsity, weights, assets under management, transaction fees, the full share restriction, and investment risk diversification are considered in this problem. However, these restrictions increase the complexity of the problem and make it a nondeterministic polynomial-time-hard problem. Metaheuristics compose the principal process of the proposed framework, as they balance a desirable tradeoff between the computational resource utilization and the quality of the obtained solution. This framework enables the constructed model to fit future data and facilitates the application of various metaheuristics. Competitive results are achieved by the proposed metaheuristic-based framework in the presented simulation.

关键词： Passive investment Index-tracking problem Metaheuristic Tracking error Excess return Risk diversification Penalty method

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DTIL-Net: Dual-Task Interactive Learning Network for Automated Grading of Diabetic Retinopathy and Macular Edema 7th

DTIL-Net: Dual-Task Interactive Learning Network for Automat...

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7th Chinese Conference on Pattern Recognition and Computer Vision

作者： Long, Jie Tana, Yumei Song, Shuxiang Xia, Haiying Guangxi Normal Univ Sch Elect & Informat Engn Guangxi Key Lab Brain Inspired Comp & Intelligent Guilin 541004 Peoples R China Guangxi Normal Univ Educ Dept Guangxi Zhuang Autonomous Reg Key Lab Integrated Circuits & Microsyst Guilin 541004 Peoples R China Guangxi Normal Univ Sch Comp Sci & Engn Guilin 541004 Peoples R China

ISBN: (纸本)9789819784950;9789819784967

Diabetic retinopathy (DR) has been the leading cause of blindness associated with a common complication of diabetic macular oedema (DME). Automatic grading of diabetic retinopathy and diabetic macular oedema can reduce the risk of blindness. However, previous studies have focused only on grading DR or DME, often ignoring the interactive association between these two diseases. In this paper, we introduce the interactive learning network (DTIL-Net) for automated grading of DR and DME. DTIL-Net aims to explore and exploit the potential correlation between DR and DME. It consists of two main components: the attention module (AM) and the dual branch exchange module (DBEM). Specifically, we propose the Attention Module to create independent branches of lesion representations for these two diseases, thus enabling cross- channel interactions between high-level semantic features. Further, we introduce the Dual Branch Exchange Module (DBEM) to facilitate the exchange of lesion feature information between the two branches through feature squeezing and excitation operations, thus establishing an intrinsic link between DR and DME. In addition, considering the fine-grained nature of lesion features, we introduce a local diversity discrimination loss ( LDD loss) to encourage the network to focus on more discriminative lesion regions. Extensive experiments on the Messidor-1 and IDRiD datasets show that DTIL-Net achieves superior results over existing state-of-the-art methods. On the Messidor-1 dataset, DR and DME classification outperform most other methods (DR: AUC: 97.0%, Acc: 93.0%;DME: AUC: 92.6%, Acc: 91.2%).

关键词： Diabetic retinopathy Diabetic macular edema Joint grading

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Wide Color Gamut and Multi-Band Color Filtration With MIM Structure Plasmonic Filters

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ADVANCED MATERIALS TECHNOLOGIES 2025年第8期10卷

作者： Zhu, Jun Wu, Zhongbo Shandong Vocat & Tech Univ Int Studies Sch Intelligent Sci & Control Engn Rizhao 276826 Shandong Peoples R China Guangxi Normal Univ Sch Elect & Informat Engn Sch Integrated Circuits Guilin 541004 Peoples R China Suzhou Univ Sci & Technol Sch Chem & Life Sci Key Lab Adv Electrode Mat Novel Solar Cells Petr & Suzhou 215009 Jiangsu Peoples R China

Color filters are extensively utilized in various applications, including photovoltaic devices, printing, liquid crystal displays, image sensors, digital photography, projection systems, and other optical instruments. In this paper, an F-P cavity structure based on an metal-insulator-metal (Ag-ZnS-Ag) structure is designed. By selecting specific materials and tuning structural parameters, strong coupling effects are formed through the interaction between the Fabry-P & eacute;rot (FP) resonance in the intermediate dielectric cavity and the LSP resonance on the metal surface. This structure can generate a narrow-band resonance peak within the visible light spectrum. By tuning the thickness of the dielectric cavity, color filtration across the 380-700 nm range can be dynamically obtained, enabling continuous multi-band filtering within visible light. Within the visible light range, this structure, functioning as a filter, can achieve a transmission efficiency of up to 56% and a FWHM of 10-24 nm. Additionally, this structure can be used to design wide-color gamut plasma filters for constructing RGB color spaces. When the ZnS thickness is 55 nm, it corresponds to the blue channel of the color space;at 75 nm, it corresponds to the green channel;and at 95 nm, it corresponds to the red channel. This color space can cover 100% of the sRGB color gamut and 99.946% of the Adobe RGB color gamut. In summary, this structure provides a new approach for designing simple, photolithography-free plasma filters that enable multi-band color filtration and exhibit a wide color gamut.

关键词： Fabry-P & eacute rot (FP) resonance localized surface plasmon (LSP) resonance multi-band color filtration RGB color space

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CFMISA: Cross-Modal Fusion of Modal Invariant and Specific Representations for Multimodal Sentiment Analysis 7th

CFMISA: Cross-Modal Fusion of Modal Invariant and Specific R...

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7th Chinese Conference on Pattern Recognition and Computer Vision

作者： Xia, Haiying Chen, Jingwen Tan, Yumei Tang, Xiaohu Guangxi Normal Univ Sch Elect & Informat Engn Guangxi Key Lab Brain Inspired Comp & Intelligent Guilin 541004 Peoples R China Guangxi Normal Univ Educ Dept Guangxi Zhuang Autonomous Reg Key Lab Integrated Circuits & Microsyst Guilin 541004 Peoples R China Guangxi Normal Univ Sch Comp Sci & Engn Guilin 541004 Peoples R China

ISBN: (纸本)9789819785018;9789819785025

Multimodal sentiment analysis aims to identify and understand sentiment using data from different information sources. However, achieving effective fusion of different modalities is challenging due to heterogeneity, information redundancy, and distributional differences between modalities. Previous approaches deal with modal heterogeneity by projecting multiple modalities into a common latent space, but ignore the valuable unique information within each modality, and thus fail to capture rich semantic information of each modality from different perspectives. To address this problem, we propose a framework called CFMISA that effectively learns the commonalities and idiosyncrasies of different modal data, and improves the robustness of sentiment analysis. Specifically, each modality is first mapped to two spaces: a public subspace and a private subspace. Among them, the public subspace contains modality-invariant representations, while the private subspace contains modality-specific representations. Subsequently, we introduce the cross-modal fusion module MCROSS to facilitate effective interaction and fusion between modality-invariant and modality-specific representations, achieving commonality fusion while preserving the diversity of each individual modality. As a result, CFMISA is able to fully exploit the useful information of each modality to achieve more effective fusion and reduce redundant information. Experimental results on the MOSI and MOSEI datasets demonstrate the effectiveness of our proposed CFMISA, outperforming most of existing methods.

关键词： Multimodal sentiment recognition Multimodal representation learning Diversity Cross-modal fusion

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Plasmonic structure: toward multifunctional optical device with controllability

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APPLIED OPTICS 2022年第34期61卷 10320-10328页

作者： Chai, Junxiong Xie, Yiyuan Ye, Yichen Liu, Bocheng Jiang, Xiao Yang, Rong Tan, Jing Southwest Univ Coll Elect & Informat Engn Chongqing 400715 Peoples R China Chongqing Key Lab Nonlinear Circuits & Intelligen Chongqing 400715 Peoples R China Univ Elect Sci & Technol China Sch Optoelect Sci & Engn Chengdu 611731 Sichuan Peoples R China

Multifunctional plasmonic components are the foundation for achieving a flexible and versatile photonic integrated loop. A compact device that can transformbetween multiple different functions is presented. The proposed structure consists of a resonator with a rotatable oval core coupled with three waveguides. The temporal coupledmode theory and finite-difference time-domain method reveal that embedding of the elliptical core alters the original resonance mode, and the rotation of the core can manipulate field distribution in the cavity. Specifically, two switchable operating wavelengths are obtained, and the wavelengths can be adjusted by modifying the structural parameters of the elliptical core. Ultimately, a multifunctional optical device with signal controllability can be realized through the rotation of the embedded rotor: power splitter with selectable wavelengths and splitting ratios;bandpass filter with controllable output ports, wavelengths, and transmissions;demultiplexer with tunable output ports and transmissions;and switch with variable output ports, wavelengths, and transmissions. The fabrication tolerance of the device is investigated, considering waveguide width and coupling distance. This multifunctional plasmonic device is of great significance for the design and implementation of optical networks-on-chips. (c) 2022 Optica Publishing Group

关键词： Bandpass filters Coupled mode theory Diffraction limit Optical devices Surface plasmon polaritons Wavelength division multiplexing

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Autonomic nervous pattern analysis of sleep deprivation

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BIOMEDICAL SIGNAL PROCESSING AND CONTROL 2022年第0期77卷 000-000页

作者： Yang, Xuehong Kong, Fanmeng Xiong, Ronglong Liu, Guangyuan Wen, Wanhui Southwest Univ Coll Elect & Informat Engn Chongqing 400715 Peoples R China Chongqing Key Lab Nonlinear Circuits & Intelligent Chongqing 400715 Peoples R China

The cumulative long-term effects of sleep deprivation (SD) have been associated with a wide range of deleterious health consequences. In order to detect SD with machine learning methods, this paper analyzed the autonomic nervous patterns (ANP) of the normal sleep (NS) populations and those of the acute sleep deprivation (ASD) individuals in the morning. Besides, we also analyzed the ANP of people before sleep deprivation (BSD) and during sleep deprivation (DSD) at night. Electrocardiogram (ECG) data were acquired from 120 subjects. Twentyfive heart rate variability (HRV) features were extracted for statistical analysis and pattern recognition. Sequential backward selection method was applied to select the critical feature subset of SD pattern recognition. Three classical classifiers were trained with BSD and DSD samples, and their performance were validated and compared with each other, in order to obtain the best parameters of the SD recognition models. The results of statistical analysis showed that the ANP of NS and ASD groups were significantly different. Besides, the ANP of NS and ASD showed significant within-group sex difference. The results of SD pattern recognition showed that, with 3-dimension critical HRV features of the night ECG data, support vector machine classifier obtained validation accuracies of 76.92% for males and 83.02% for females. It is worth noting that, the low-frequency power of RR interval series increases with the increase of SD time, showing that SD leads to persistent activation of sympathetic nervous system.

关键词： Sleep deprivation Autonomic nervous system Heart rate variability Machine learning

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An inertial neurodynamic algorithm for collaborative time-varying energy management for energy internet containing distributed energy resources

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INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS 2023年第1期154卷

作者： Zhao, Gui He, Xing Li, Chaojie Southwest Univ Coll Elect & Informat Engn Chongqing Key Lab Nonlinear Circuits & Intelligent Chongqing 400715 Peoples R China Hong Kong Polytech Univ Dept Elect & Elect Engn Hong Kong Peoples R China

This paper investigates the energy management of an Energy Internet (EI) that integrates multiple energy networks. Based on the structure of EI and the fluctuation of load, an optimal energy management model considering part of the load as time-varying factor is proposed. Under the influence of load, the actual energy management problem (EMP) is formulated as a time-varying optimization problem subject to a set of global and local constraints. Its optimal solution varies continuously with time, which leads to difficulties in obtaining optimal solutions by conventional algorithms. Consequently, to obtain better tracking performance, this paper proposes a distributed inertial projection neurodynamics algorithm (DIPNA) based on the Nesterov accelerated gradient descent method. This algorithm tracks the optimal solution of the EMP with a fast convergence rate O (1/��2), providing a referenceable active power for each energy unit in real time. Finally, the performance evaluation results demonstrated the effectiveness and fast convergence of the proposed algorithm.

关键词： Energy management Energy internet Inertial neurodynamics Time-varying Convergence rate

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Distributed Nesterov Gradient and Heavy-Ball Double Accelerated Asynchronous Optimization

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IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 2021年第12期32卷 5723-5737页

作者： Li, Huaqing Cheng, Huqiang Wang, Zheng Wu, Guo-Cheng Southwest Univ Coll Elect & Informat Engn Chongqing Key Lab Nonlinear Circuits & Intelligen Chongqing 400715 Peoples R China Neijiang Normal Univ Coll Math & Informat Sci Data Recovery Key Lab Sichuan Prov Neijiang 641100 Peoples R China

In this article, we come up with a novel Nesterov gradient and heavy-ball double accelerated distributed synchronous optimization algorithm, called NHDA, and adopt a general asynchronous model to further propose an effective asynchronous algorithm, called ASY-NHDA, for distributed optimization problem over directed graphs, where each agent has access to a local objective function and computes the optimal solution via communicating only with its immediate neighbors. Our goal is to minimize a sum of all local objective functions satisfying strong convexity and Lipschitz continuity. Consider a general asynchronous model, where agents communicate with their immediate neighbors and start a new computation independently, that is, agents can communicate with their neighbors at any time without any coordination and use delayed information from their in-neighbors to compute a new update. Delays are arbitrary, unpredictable, and time-varying but bounded. The theoretical analysis of NHDA is based on analyzing the interaction among the consensus, the gradient tracking, and the optimization processes. As for the analysis of ASY-NHDA, we equivalently transform the asynchronous system into an augmented synchronous system without delays and prove its convergence through using the generalized small gain theorem. The results show that NHDA and ASY-NHDA converge to the optimal solution at a linear convergence as long as the largest step size is positive and less than an explicitly estimated upper bound, and the largest momentum parameter is nonnegative and less than an upper bound. Finally, we demonstrate the advantages of ASY-NHDA through simulations.

关键词： Optimization Convergence Delays Acceleration Directed graphs Approximation algorithms Computational modeling Asynchrony directed graph distributed optimization heavy ball linear convergence rate Nesterov

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