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Brockett's Second Example:A FAS Approach Treatment

Journal of systems Science & Complexity 2023年第5期36卷 1789-1808页

作者： DUAN Guang-Ren Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China Center for Control Theory and Guidance Technology Harbin Institute of TechnologyHarbin 150001China

In this paper,several equivalent forms of the well-known Brockett's second example system are firstly *** stabilization of the system is then treated in the fully actuated system approach.A simple continuous time-invariant sub-stabilizing controller is designed,and the corresponding region of attraction is *** a result,all trajectories of the system starting from the characterized region of attraction are driven exponentially to the *** the region of attraction is very large,the designed sub-stabilizing controller can be directly useful in many practical *** cases where the initial values are indeed needed to be chosen out of the region of attraction,extremely simple pre-controllers can be designed,which drive the system trajectories into the designed region of attraction.A simulation of the designed control system is carried out to show the effect of the proposed approach.

关键词： Brockett integrator continuous time-invariant controllers fully actuated system approach region of attraction sub-stabilization

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Characteristic model-based control of aerial manipulator for improved interaction stability

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Science China(Technological Sciences) 2025年第4期68卷 166-178页

作者： Bingkai XIU Zhan LI Yipeng YANG Huijun GAO Research Institute of Intelligent Control and Systems Harbin Institute of TechnologyHarbin150001China State Key Laboratory of Robotics and Systems(HIT) Harbin Institute of TechnologyHarbin150001China

Maintaining contact stability is crucial when the aerial manipulator interacts with the surrounding environment. In this paper, a novel output feedback framework based on a characteristic model is proposed to improve the contact stability of the aerial manipulator. First, only position measurements of the aerial manipulator are introduced to design the practical finite-time command filter-based force observer. Second, an attitude control architecture including characteristic modeling and controller design is presented. In the modeling part, input-output data is utilized to build the characteristic model with fewer parameters and a simpler structure than the traditional dynamic model. Different from conventional control methods, fewer feedback values,namely only angle information, are required for designing the controller in the controller part. In addition, the convergence of force estimation and the stability of the attitude control system are proved by the Lyapunov analysis. Numerical simulation comparisons are conducted to validate the effectiveness of the attitude controller and force observer. The comparative results demonstrate that the tracking error of x and θ channels decreases at least 10.62% and 10.53% under disturbances and the force estimation precision increases at least 45.19% in the different environmental stiffness. Finally, physical flight experiments are conducted to validate the effectiveness of the proposed framework by a self-built aerial manipulator platform.

关键词： aerial manipulator interaction stability contact force observer characteristic model

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Fixed-time stabilization of discontinuous spatiotemporal neural networks with time-varying coefficients via aperiodically switching control

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Science China(Information Sciences) 2023年第5期66卷 182-195页

作者： Xiaofang HU Leimin WANG Chuan-Ke ZHANG Xiongbo WAN Yong HE School of Automation China University of Geosciences Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of Education

This paper focuses on the challenge of fixed-time control for spatiotemporal neural networks(SNNs) with discontinuous activations and time-varying coefficients. A novel fixed-time convergence lemma is proposed, which facilitates the handling of time-varying coefficients of SNNs and relaxes the restriction on the non-positive definiteness of the derivative of the Lyapunov function. Besides, a more flexible and economical aperiodically switching control technique is presented to stabilize SNNs within a fixed time,efectively reducing the amount of information transmission and control costs. Under the newly established fixed-time convergence lemma and aperiodically switching controller, many more general algebraic conditions are deduced to ensure the fixed-time stabilization of SNNs. Numerical examples are provided to manifest the validity of the results.

关键词： spatiotemporal neural networks discontinuous activations time-varying coefficients fixed-time stabilization aperiodically switching control

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Aerial target threat assessment based on gated recurrent unit and self-attention mechanism

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Journal of systems Engineering and Electronics 2024年第2期35卷 361-373页

作者： CHEN Chen QUAN Wei SHAO Zhuang School of Automation Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing 100081China

Aerial threat assessment is a crucial link in modern air combat, whose result counts a great deal for commanders to make decisions. With the consideration that the existing threat assessment methods have difficulties in dealing with high dimensional time series target data, a threat assessment method based on self-attention mechanism and gated recurrent unit(SAGRU) is proposed. Firstly, a threat feature system including air combat situations and capability features is established. Moreover, a data augmentation process based on fractional Fourier transform(FRFT) is applied to extract more valuable information from time series situation features. Furthermore, aiming to capture key characteristics of battlefield evolution, a bidirectional GRU and SA mechanisms are designed for enhanced ***, after the concatenation of the processed air combat situation and capability features, the target threat level will be predicted by fully connected neural layers and the softmax classifier. Finally, in order to validate this model, an air combat dataset generated by a combat simulation system is introduced for model training and testing. The comparison experiments show the proposed model has structural rationality and can perform threat assessment faster and more accurately than the other existing models based on deep learning.

关键词： target threat assessment gated recurrent unit(GRU) self-attention(SA) fractional Fourier transform(FRFT)

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Two Peaks of Seasonal Influenza Epidemics -China, 2023

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China CDC weekly 2024年第36期6卷 905-910页

作者： Yiran Xie Shuxia Lin Xiaoxu Zeng Jing Tang Yanhui Cheng Weijuan Huang Jiandong Li Dayan Wang National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Disease National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina.

Introduction:Influenza is a communicable respiratory disease that causes annual epidemics and occasional unpredictable *** study examines the occurrence of two unexpected influenza peaks within the year ***:Influenza-like illness(ILI)data were reported,and specimens of ILI were collected by designated surveillance *** cases were confirmed using real-time reverse transcription polymerase chain reaction(rRT-PCR)testing conducted at national surveillance network *** data were then submitted to the Chinese Influenza Surveillance Information ***:From December 2022 to January 2023,influenza activity was minimal until a spring epidemic began in February,peaking in late *** outbreak spread from the north to the south,with A(H1N1)pdm09 being the predominant strain and A(H3N2)also circulating *** positivity rate in northern and southern provincial-level administrative divisions(PLADs)reached 60.0%(week 10)and 60.2%(week 13),respectively,before dropping to below 5%from May to ***,rates surged starting in week 41 in the south and week 44 in the north,peaking at 54.4%(week 50)and 44.0%(week 49),respectively,and remained high until the end of 2023.A(H3N2)became the prevailing strain,with a notable increase in B/Victoria lineage viruses from December,resulting in two peaks during the 2023 influenza ***:The pattern of the influenza epidemic shifted due to the coronavirus disease 2019(COVID-19)outbreak and is gradually returning to its usual seasonal and intensity *** is,therefore,crucial to continuously strengthen influenza surveillance,enhance the influenza surveillance network,and lay the groundwork for advancing integrated surveillance of multiple pathogens in China.

关键词： prevailing surveillance Influenza

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Genomic Surveillance for SARS-CoV-2 Variants: Dominance of XBB Replacement — China, January–June 2023

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China CDC weekly 2024年第15期6卷 324-331页

作者： Yenan Feng Qiudong Su Lili Li Xiaozhou He Peihua Niu Xiaojuan Guo Xiang Zhao Jing Tang Zhiyuan Jia Ji Wang Changcheng Wu Baicheng Xia Zhixiao Chen Yuchao Wu Jing Yang Songqi Chen Cao Chen Shiwen Wang Xiaoping Dong National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina NHC Key Laboratory of Medical Virology and Viral Diseases National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina

Introduction:In the first half of 2023,a global shift was observed towards the predominance of XBB *** faced a significant epidemic between late 2022 and early 2023 due to Omicron subvariants BA.5.2 and *** study aims to depict the evolving variant distribution among provincial-level administrative divisions(PLADs)in China and explore the factors driving the predominance of XBB ***:Sequences from local and imported coronavirus disease 2019(COVID-19)cases recorded between January 1 and June 30,2023,were *** study analyzed the changing distribution of viral variants and assessed how the prior dominance of specific variants,XBB subvariants,and imported cases influenced the prevalence of the XBB replacement ***:A total of 56,486 sequences were obtained from local cases,and 8,669 sequences were from imported *** in April,there was a shift in the prevalence of XBB from imported to local cases,with varying dominance among *** PLADs previously high in BF.7,the rise of XBB was delayed.A positive correlation was found between XBB proportions in imported cases from January to March and local cases in *** distribution pattern of XBB subvariants differed between local and imported cases within the same *** significant differences were noted in the replacement rates of XBB ***:The timing of XBB dominance differed among various PLADs in China in the first half of 2023,correlating closely with the prevalence of XBB variants among imported cases.

关键词： dominance imported distribution

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Willingness to Pay for Antiretroviral Drugs Covered by Medical Insurance among People Living with HIV in 18 Chinese Cities

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Biomedical and Environmental Sciences 2024年第11期37卷 1283-1293页

作者： Jingkun Hu Houlin Tang Wenting Kang Shuyu Wang Jie Xu Decai Zhao Yang Hao Xinlun Wang Fan Lyu Guang Zhang Peng Xu National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijing 102206China Chinese Association of STD&AIDS Prevention and Control Beijing 100050China National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Center for AIDS/STD Control and PreventionChinese Center for Disease Control and Prevention Beijing 102206China

Objective Antiretroviral drugs covered by medical insurance have been gradually used by people living with human immunodeficiency virus(PLWH)in recent years in *** study aimed to analyze their willingness to pay(WTP)for antiretroviral *** A mixed-methods study design involving a cross-sectional survey and in-depth interviews was conducted.A cross-sectional survey was performed to collect data on the general characteristics,economic status,antiretroviral therapy(ART)status,and WTP of PLWH in 18 Chinese cities from August 2022 to February *** logistic regression was used to analyze the factors associated with *** of PLWH were interviewed via in-depth interviews,and the data were thematically *** Among the 941 PLWH,271(28.80%)were willing to pay for antiretroviral drugs covered by medical *** basic medical insurance for urban and rural residents,PLWH with the following characteristics were more willing to pay:an educational level of senior high school or technical secondary school,having an undergraduate degree or higher,frequently working away from their hometowns,and homosexual ***-farm workers and recipients of government medical aid were more unwilling to *** basic medical insurance for urban employees,PLWH with the following characteristics were more willing to pay:frequently working away from their hometowns;homosexual transmission;personal annual income≥100,000 CNY;and adverse events of antiretroviral *** main reasons for PLWH’s WTP for antiretroviral drugs covered by medical insurance were that the drugs had fewer adverse events and were easier to *** main reasons for PLWH’s unwillingness to pay were financial difficulties and privacy *** Nearly one-third of PLWH are willing to pay for antiretroviral drugs covered by medical *** the future,PLWH with a high WTP can be guided to use these drugs.

关键词： PLWH Antiretroviral drugs covered by medical insurance Willingness to pay

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Emergence of Erythromycin-Resistant and Pertactin-and Filamentous Hemagglutinin-Deficient Bordetella pertussis Strains—Beijing,China,2022-2023

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China CDC weekly 2024年第20期6卷 437-441页

作者： Guilan Zhou Ying Li Hairui Wang Yuanyuan Wang Yuan Gao Juan Xu Fengshuang Wang Tao Peng Maojun Zhang Zhujun Shao National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina Shunyi District Center for Disease Control and Prevention BeijingChina

What is already known about this topic?Pertussis has reemerged as a significant public health threat,primarily due to variations in Bordetella pertussis strains,antimicrobial resistance,and vaccine *** is added by this report?All isolated strains were identified as ptxA1/ptxC2/ptxP3/prn150/fim2-1/fim3-1/fhaB1/tcfA2 type and exhibited resistance to erythromycin.

关键词： vaccine pertussis primarily

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Time-Varying Formation Tracking control of Heterogeneous Multi-Agent systems With Intermittent Communications and Directed Switching Networks

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IEEE/CAA Journal of Automatica Sinica 2025年第1期12卷 294-296页

作者： Yuhan Wang Zhuping Wang Hao Zhang Huaicheng Yan the Shanghai Research Institute for Intelligent Autonomous Systems Tongji University the National Key Laboratory of Autonomous Intelligent Unmanned Systems the Frontiers Science Center for Intelligent Autonomous System of Ministry of Education the College of Electronic and Information Engineering the Department of Control Science and Engineering Tongji University the Key Laboratory of Advanced Control and Optimization for Chemical Processes of Ministry of Education the School of Information Science and Engineering East China University of Science and Technology

Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present so... 详细信息

关键词： Switches Topology Observers Formation control Event detection Switched systems Multi-agent systems control theory Autonomous systems Stability

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Risk Assessments for Type 1 Wild Poliovirus and Type 2 Vaccine-Derived Poliovirus Importation and Transmission—China,2023

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China CDC weekly 2024年第42期6卷 1098-1104,I0007,I0008页

作者： Wei Kang Chunxiang Fan Yifan Song Zhaonan Zhang Xiaoqi Wang Miao Wang Jing Ma Mulei Chen Yuzhen Yang Yi Wen Lei Cao Lance Rodewald Fuzhen Wang Zundong Yin Ning Wen Hong Yang National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Chinese Center for Disease Control and PreventionBeijingChina National Immunization Program Chinese Center for Disease Control and PreventionBeijingChina Education and Training of Chinese Center for Disease Control and Prevention BeijingChina

Introduction:All countries face the potential threat of imported polioviruses,including both wild type and circulating vaccine-derived *** response,we conducted a province-level assessment in China to evaluate the risk of importation and transmission of type 1 wild poliovirus(WPV1)and type 2 vaccine-derived poliovirus(VDPV2).Methods:Distinct risk assessment tools for WPV1 and VDPV2 were employed,incorporating three primary indicators—population immunity,poliovirus surveillance,and importation ***1 was assessed using 13 secondary indicators,whereas VDPV2 utilized 21 secondary *** used comprehensive provincial data from the preceding five ***(S-values)were derived from the secondary indicators’criteria and ratings,and used to classify the provincial-level administrative divisions(PLADs)into three risk categories:high,medium,and *** top 10%of PLADs were designated as highrisk,with the remaining provinces equally distributed into medium-and low-risk ***:In 2023,Xizang,Qinghai,and Xinjiang PLADs faced the highest risk of WPV1 importation and transmission;Xizang,Shaanxi,and Hainan PLADs were at the greatest risk for VDPV2 importation and ***:Risk assessment for VDPV2 importation and transmission has identified a distinct set of high-risk provinces compared to those identified by WPV1 risk *** and proactive response measures tailored to the specific risks should be implemented to maintain China’s polio-free status.

关键词： immunity maintain utilized

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